KR20230015662A - Turbo compressor - Google Patents

Abstract

According to the present invention, a turbo compressor may comprise a suction side sealing part made of labyrinth seal provided on at least one of an inner circumferential surface of an impeller accommodating part, and an outer circumferential surface of an impeller facing the inner circumferential surface of the impeller accommodating part. Through this, the refrigerant compressed while passing through the impeller can be prevented from leaking by flowing backward from the discharge side of the impeller to the suction side, thereby increasing compressor efficiency.

Description

Turbo compressor {TURBO COMPRESSOR}

The present invention relates to turbocompressors.

In general, compressors can be largely divided into positive displacement type compressors and turbo type compressors. The volumetric compressor uses a piston or a vane like a reciprocating or rotary type compressor to suck in, compress, and then discharge fluid. On the other hand, the turbo-type compressor uses a rotating element to suction, compress, and then discharge the fluid.

The positive displacement compressor determines the compression ratio by appropriately adjusting the ratio of the suction volume and the discharge volume to obtain a desired discharge pressure. Therefore, the positive displacement compressor is limited in miniaturizing the overall size of the compressor relative to its capacity.

A turbo compressor is similar to a turbo blower, but has a higher discharge pressure and a smaller flow rate than a turbo blower. These turbocompressors increase the pressure of continuously flowing fluid, and can be divided into an axial flow type when the fluid flows in an axial direction and a centrifugal type when the fluid flows in a radial direction.

On the other hand, unlike volumetric compressors such as reciprocating compressors and rotary compressors, turbo compressors achieve the desired high pressure ratio with only one compression due to various factors such as workability, mass productivity, and durability, even if the blade shape of the rotating impeller is optimally designed. It is difficult. Accordingly, a multistage type turbocompressor is known which includes a plurality of impellers in an axial direction to compress fluid in multiple stages.

A multi-stage turbo compressor is known in which a plurality of impellers are installed on a rotating shaft at one side of a rotor or a plurality of impellers are installed to face each other at both ends of a rotating shaft with a rotor interposed therebetween to compress fluid in multiple stages. For convenience, the former can be classified into a one-sided type and the latter into a both-end type.

The single-sided turbocompressor can suppress a decrease in compressor efficiency by shortening pipes or fluid passages connecting a plurality of impellers. However, in the one-sided turbo compressor, the thrust directions of both impellers are in the same direction, so axial fluctuations increase accordingly, and as a result, the size of the thrust bearing increases, and the overall size of the compressor may increase. In addition, as the load applied to the driving unit increases during high-speed operation, the driving unit may overheat.

In the double-ended turbo compressor, thrust directions of both impellers are opposite to each other, so that axial fluctuations can be suppressed to a certain extent, thereby reducing the size of the thrust bearing and increasing motor efficiency. However, in the case of the double-ended type, complicated and long pipes or fluid passages are required to connect the plurality of impellers, which not only complicates the structure of the compressor, but also moves the compressed fluid from one impeller to the other impeller through a long flow path. Pressure loss may occur in the compressor and the efficiency of the compressor may decrease.

Patent Document 1 (US Patent Registration US5857348 B, registration date: 1999.01.12.) discloses an example of a double-ended turbo compressor. The double-stage turbocompressor disclosed in Patent Document 1 has a first impeller constituting a first compression unit (hereinafter referred to as a first compression unit) on one side of a rotating shaft and a two-stage compression unit (hereinafter referred to as a second compression unit) on the other side of the rotation shaft. The second impeller is provided, respectively, and connects the outlet of the first compression unit and the inlet of the second compression unit through a communication pipe.

In the double-ended turbo compressor as described above, radial bearings and axial bearings are provided at both ends or one end of a rotating shaft around the driving unit. As conventional turbo compressors, including double-ended turbo compressors, rotate at high speed (eg, 40,000 rpm or more), it is advantageous in terms of compressor efficiency to rapidly dissipate heat generated from the motor heat generated from the drive unit and frictional heat from the bearing supporting the rotating shaft. do.

Patent Document 2 (US Patent Registration US8931304 B2, Registration Date: 2015.01.13.) discloses a double-ended turbo compressor. In the double-stage turbocompressor disclosed in Patent Document 2, the refrigerant compressed in the first stage in the first compression unit is guided to the motor chamber, and the drive motor and bearing are cooled using the refrigerant compressed in the first stage led to the motor chamber, and then transferred to the second compression unit. The intake refrigerant flow path is disclosed.

In the turbo compressor having the refrigerant flow path as described above, as the high-temperature refrigerant compressed in the first stage passes through the drive motor and the bearing, there is a limit to effectively cooling the motor heat and friction heat. In addition, as the refrigerant preheated while passing through the motor chamber is sucked into the second compression unit, the specific volume of the refrigerant increases, resulting in volume loss, which may decrease compression efficiency in the second compression unit.

US registered patent US5857348 B (registration date: 1999.01.12.) US registered patent US8931304 B2 (registration date: 2015.01.13.)

An object of the present invention is to provide a turbo compressor capable of improving compressor performance by increasing the amount of refrigerant sucked into an impeller through a suction port.

Furthermore, the present invention is to provide a turbo compressor capable of suppressing leakage of compressed refrigerant passing through the impeller by flowing backward from the discharge side to the suction side through a gap between the outer circumferential surface of the impeller and a shroud surrounding the impeller.

Furthermore, an object of the present invention is to provide a turbo compressor having a suction-side sealing portion between an outer circumferential surface of an impeller and an inner circumferential surface of a shroud surrounding the impeller, but which can simplify the structure of the suction-side sealing portion.

Another object of the present invention is to provide a turbo compressor capable of rapidly dissipating heat generated from a motor housing.

Another object of the present invention is to provide a turbo compressor capable of stably supporting a rotary shaft rotating at high speed using a gas foil bearing.

Another object of the present invention is to provide a turbo compressor capable of optimizing compressor performance according to load.

In order to achieve the object of the present invention, the housing; And a turbo compressor including at least one or more impellers rotatably provided in the housing may be provided. The housing may include a suction port, a discharge port, an impeller accommodating portion, and a suction side sealing portion. The inlet may be formed at one end of the housing. The outlet may communicate with the inlet. The impeller accommodating portion is provided between the suction port and the discharge port, and the impeller may be rotatably inserted therein. The suction-side accommodating portion may be provided on at least one of an inner circumferential surface of the impeller accommodating portion and an outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating portion. Through this, the refrigerant compressed while passing through the impeller can be prevented from flowing back from the discharge side of the impeller to the suction side and leaking, thereby increasing the efficiency of the compressor.

For example, the suction-side sealing portion may be formed in at least one line along the axial direction. For example, the suction side sealing part may be formed radially on at least one of an inner circumferential surface of the impeller accommodating part and an outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating part. Through this, it is possible to effectively suppress refrigerant leakage from the suction side while simplifying the structure of the suction side sealing unit provided on the suction side of the impeller.

For example, the suction-side sealing portion may include an inner sealing portion formed on an outer circumferential surface of the impeller; And it may include an outer sealing portion formed on the inner circumferential surface of the impeller accommodating portion facing the outer circumferential surface of the impeller. The inner sealing part and the outer sealing part may be formed unevenly so as to be engaged with each other. Through this, the gap between the outer circumferential surface of the impeller and the shroud facing it forms a zigzag shape, so that the sealing distance is narrow and long, and refrigerant leakage from the suction side can be more effectively suppressed. .

Specifically, protrusions and grooves of the outer sealing portion may be alternately formed along an axial direction. Grooves corresponding to the protrusions of the outer sealing portion and protrusions corresponding to the grooves of the outer sealing portion may be alternately formed along the axial direction of the inner sealing portion. At least a portion of the projections of the outer sealing part and the projections of the inner sealing part may overlap in an axial direction. Through this, the suction-side sealing portion is formed to be engaged with each other between the outer circumferential surface of the impeller and the shroud facing it, so that the leakage gap between the impeller and the shroud is formed narrow and long, and refrigerant leakage from the suction side can be more effectively suppressed.

For example, a driving motor may be provided in the housing, the impeller may be coupled to an end of a rotating shaft coupled to a rotor of the driving motor, and a bearing supporting the rotating shaft may be provided between the rotating shaft and the housing. there is. A gap between the inner sealing part and the outer sealing part may be greater than or equal to a gap between the bearing and the rotating shaft. Through this, while forming the sealing passage of the suction-side sealing part as complicated and long as possible, the gap between the sealing passages is formed to be greater than or equal to the behavior of the rotating shaft, so that the reliability of the suction sealing part is reduced due to the behavior of the rotating shaft. It can be suppressed.

The housing according to this embodiment includes a motor housing; and an impeller housing provided with the impeller accommodating portion and coupled in an axial direction from an end side of the motor housing. The impeller housing may be composed of a plurality of housing blocks assembled in a radial direction. Through this, the impeller can be closely accommodated in the impeller housing while the suction-side sealing portion is formed to be engaged with each other between the outer circumferential surface of the impeller and the shroud facing the impeller.

Specifically, each of the plurality of housing blocks may include a portion of the impeller accommodating portion. A portion of the outer sealing portion may be provided in each of the impeller accommodating portions. An inner sealing portion may be provided on an outer circumferential surface of the impeller to form the suction-side sealing portion in engagement with the outer sealing portion. Through this, it is possible to increase the sealing effect at the suction side by forming the suction-side sealing portion to be engaged with each other between the outer circumferential surface of the impeller and the shroud facing the impeller.

More specifically, the inner sealing portion may have a plurality of annular protrusions and annular grooves alternately formed along the axial direction. The outer sealing portion may have a plurality of annular grooves and annular protrusions alternately formed along an axial direction. The annular projection of the inner sealing part is radially inserted into the annular groove of the outer sealing part at a predetermined interval, and the annular projection of the outer sealing part is radially inserted into the annular groove of the inner sealing part at a predetermined interval. there is.

For example, a plurality of annular projections of the inner sealing part and annular projections of the outer sealing part may be formed along an axial direction. Each of the plurality of annular protrusions may have the same radial height. Through this, while increasing the sealing effect in the suction-side sealing portion, it is possible to facilitate processing of the inner sealing portion and the outer sealing portion constituting the suction-side sealing portion.

On the other hand, the housing, the motor housing; and an impeller housing provided with the impeller accommodating portion and coupled in an axial direction from an end side of the motor housing. The impeller housing may be formed such that the impeller accommodating portion extends from the inlet at the center and penetrates in the axial direction. Through this, it is possible to easily manufacture and assemble the impeller housing while forming the suction-side sealing portion in the impeller accommodating portion.

Specifically, on the outer circumferential surface of the impeller, annular projections and annular grooves constituting the suction-side sealing portion may be alternately formed along the axial direction. A sealing part accommodating groove may be formed stepwise on an inner circumferential surface of the impeller accommodating part so that the suction side sealing part is inserted. Through this, while simplifying the suction-side sealing portion, it is possible to easily manufacture and assemble the impeller housing having the suction-side sealing portion.

More specifically, a plurality of the annular protrusions may be formed along the axial direction. The annular protrusion may be formed with a radial height increasing from a side of the inlet to a side of the outlet. The sealing unit accommodating groove may be formed in multiple stages, the inner diameter of which increases from the suction port toward the discharge port. Through this, it is possible to simplify the suction-side sealing part to facilitate the manufacture and assembly of the impeller housing having the suction-side sealing part, while further extending the sealing distance to increase the sealing effect.

As another example, a plurality of impellers may be provided, and the plurality of impellers may be rotatably accommodated in a plurality of different impeller accommodating units, respectively. Among the plurality of impellers, the discharge side of the first impeller located on the current side may communicate with the suction side of the second impeller located on the downstream side. The suction side sealing part may be provided between the outer circumferential surface of the plurality of impellers and the inner circumferential surface of the plurality of impeller accommodating portions accommodating the plurality of impellers. Through this, it is possible to further increase compressor efficiency by reducing suction loss in the plurality of compression units.

As another example, a plurality of impellers may be provided, and the plurality of impellers may be rotatably accommodated in a plurality of different impeller accommodating units, respectively. Among the plurality of impellers, the discharge side of the first impeller located on the current side may communicate with the suction side of the second impeller located on the downstream side. The suction-side sealing portion may be provided between an outer circumferential surface of the first impeller and an inner circumferential surface of the first impeller accommodating portion accommodating the first impeller. Through this, it is possible to suppress an excessive increase in the manufacturing cost of the compressor by simplifying the sealing structure while increasing the efficiency of the compressor by reducing the suction loss in the compression part where the refrigerant leakage is relatively large among the plurality of compression parts.

On the other hand, the impeller may be provided with a shroud coupled to surround the outer surface of the blade. The shroud may include an inlet portion adjacent to the inlet; and an outlet portion extending from the inlet portion and adjacent to the discharge port. The suction-side sealing portion may be provided between an outer circumferential surface of the inlet portion and an inner circumferential surface of the impeller accommodating portion facing the outer circumferential surface of the inlet portion. Through this, it is possible to increase the sealing effect while easily forming the suction-side sealing part.

In order to achieve the object of the present invention, a housing, a driving motor, a rotating shaft, a first compression unit and a second compression unit, a connection passage, an inflow passage, and an outflow passage may be included. The housing may include a motor room. The driving motor may include a stator and a rotor and be fixed to the motor room of the housing. The rotating shaft may be rotatably provided by being coupled to the rotor. The first compression unit and the second compression unit may be provided at both ends of the rotating shaft, respectively. The connection passage may be provided to connect an outlet of the first compression unit and an inlet of the second compression unit. The inflow passage may pass through one side of the housing, communicate with the inside of the motor room, and guide cooling fluid to the inside of the motor room. The outflow passage may be provided to pass through the other side of the housing, communicate with the inside of the motor room, and guide the cooling fluid in the motor room to the outside of the housing. Through this, the cooling fluid is supplied to the motor room to rapidly operate the gas foil bearing provided in the motor room, and at the same time, heat generated in the motor room can be quickly dissipated even during high-speed operation, thereby increasing the efficiency of the turbo compressor.

In order to achieve the object of the present invention, a housing accommodating a first compression unit and a second compression unit, a connection passage connecting a discharge side of the first compression unit and a suction side of the second compression unit, and a refrigerant communicated with the housing. An inflow passage part and an outflow passage part for circulating and supplying may be included. The outflow passage part may include a first connection passage, a second connection passage, and a refrigerant control valve. One end of the first connection passage may communicate with the second space, and the other end may communicate with the connection passage. One end of the second connection passage may be in communication with the connection passage part, and the other end may be in communication with an inlet side of the first compression part. The refrigerant control valve may be configured to control a flow direction of the refrigerant passing through the motor chamber toward the first connection passage or the second connection passage. Through this, the refrigerant passing through the motor room may be appropriately guided to the first compression unit or the second compression unit according to the operation mode of the compressor, thereby optimizing compression efficiency.

In the turbocompressor according to the present invention, a suction-side sealing unit may be provided on at least one of the inner circumferential surface of the impeller accommodating part and the outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating part. Through this, the refrigerant compressed while passing through the impeller can be prevented from flowing back from the discharge side of the impeller to the suction side and leaking, thereby increasing the efficiency of the compressor.

In addition, the suction-side sealing portion of the present invention may be formed radially on at least one of the inner circumferential surface of the impeller accommodating portion and the outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating portion. Through this, while simplifying the structure of the suction-side sealing portion provided on the suction side of the impeller, the suction-side sealing portion is formed in a zigzag shape so that the sealing distance at the suction side is narrow and long, and refrigerant leakage can be effectively suppressed.

In addition, the distance between the inner sealing part and the outer sealing part constituting the suction side sealing part of the present invention may be formed to be greater than or equal to the gap between the bearing and the rotating shaft. Through this, while forming the sealing passage of the suction-side sealing part as complicated and long as possible, the gap between the sealing passages is formed to be greater than or equal to the behavior of the rotating shaft, so that the reliability of the suction sealing part is reduced due to the behavior of the rotating shaft. It can be suppressed.

In addition, the housing according to the present invention includes an impeller housing provided with an impeller accommodating portion and coupled in an axial direction from an end side of the motor housing, but the impeller housing may be composed of a plurality of housing blocks assembled in a radial direction. Through this, the impeller can be closely accommodated in the impeller housing while the suction-side sealing portion is formed to be engaged with each other between the outer circumferential surface of the impeller and the shroud facing the impeller.

In addition, in the present invention, a plurality of annular projections of the inner sealing part and annular projections of the outer sealing part constituting the suction side sealing part are formed along the axial direction, respectively, and each may have the same radial height. Through this, while increasing the sealing effect in the suction-side sealing portion, it is possible to facilitate processing of the inner sealing portion and the outer sealing portion constituting the suction-side sealing portion.

In addition, in the impeller housing according to the present invention, the sealing part accommodating groove may be formed stepwise on the inner circumferential surface of the impeller accommodating part so that the suction side sealing part is inserted. Through this, while simplifying the suction-side sealing portion, it is possible to easily manufacture and assemble the impeller housing having the suction-side sealing portion.

In addition, in the impeller housing of the present invention, a sealing unit accommodating groove is formed on its inner circumferential surface, and the sealing unit accommodating groove may be formed in multiple stages corresponding to the radial height of the annular projection provided on the outer circumferential surface of the impeller. Through this, it is possible to simplify the suction-side sealing part to facilitate the manufacture and assembly of the impeller housing having the suction-side sealing part, while further extending the sealing distance to increase the sealing effect.

In addition, in the present invention, a suction-side sealing portion may be provided between the outer circumferential surface of the plurality of impellers and the inner circumferential surface of the plurality of impeller accommodating portions, respectively. Through this, it is possible to further increase compressor efficiency by reducing suction loss in the plurality of compression units.

In addition, in the present invention, a suction-side sealing portion may be provided between the outer circumferential surface of the first impeller constituting the first-stage compression unit among the plurality of compression units and the inner circumferential surface of the first impeller accommodating unit. Through this, it is possible to suppress an excessive increase in the manufacturing cost of the compressor by simplifying the sealing structure while increasing the efficiency of the compressor by reducing the suction loss in the compression part where the refrigerant leakage is relatively large among the plurality of compression parts.

In the turbo compressor according to the present invention, an inlet passage portion passing through one side of the housing and communicating with the inside of the motor room and guiding the cooling fluid to the inside of the motor room, passing through the other side of the housing and communicating with the inside of the motor room, and the motor An outflow passage for guiding the cooling fluid in the seal to the outside of the housing may be included. Through this, the cooling fluid is supplied to the motor room to quickly drive the gas foil bearings provided in the motor room, and at the same time, the heat generated in the motor room is quickly dissipated even during high-speed operation, resulting in the efficiency of the turbo compressor and the refrigeration cycle device equipped with it. can increase

The turbo compressor according to the present invention may include a refrigerant control valve between the first connection passage and the second connection passage to select and connect the refrigerant passing through the motor chamber to the suction side of the second compression unit or the suction side of the first compression unit. . Through this, the refrigerant passing through the motor room may be appropriately guided to the first compression unit or the second compression unit according to the operation mode of the compressor, thereby optimizing compression efficiency.

1 is a schematic diagram showing a refrigeration cycle including a turbo compressor according to this embodiment;
2 is an exploded perspective view of the turbo compressor according to the present embodiment;
Figure 3 is a perspective view showing the inside of the assembly of the turbo compressor according to Figure 2;
Figure 4 is a cross-sectional view showing the inside of the turbo compressor according to Figure 3;
5 is an enlarged cross-sectional view of the first compression unit in FIG. 4;
Figure 6 is an enlarged cross-sectional view of the second compression unit in Figure 4;
7A and 7B are schematic diagrams shown to explain refrigerant flow for each operation mode in the turbo compressor according to the present embodiment;
8 is a flow chart shown to explain a process of controlling a flow direction of a refrigerant in a turbo compressor according to the present embodiment;
9 is a perspective view showing a separated first impeller housing according to this embodiment;
10 is a front view showing the assembly of the first impeller housing of FIG. 9;
11 is an enlarged cross-sectional view of the first suction-side sealing part and the second suction-side sealing part in FIG. 4;
12 is a perspective view showing a broken first impeller housing having a first suction-side sealing part according to another embodiment;
13 is an enlarged cross-sectional view of the first suction-side sealing part in FIG. 12;
14 is a perspective view showing a broken first impeller housing having a first suction-side sealing part according to another embodiment;
15 is an enlarged cross-sectional view of the first suction-side sealing part in FIG. 14;

Hereinafter, a turbo compressor according to the present invention and a refrigerating cycle device equipped with the same will be described in detail by an embodiment shown in the accompanying drawings. In this embodiment, the first impeller and the second impeller are installed at both ends of the rotating shaft, and the outlet of the first compression unit including the first impeller is connected to the inlet of the second compression unit including the second impeller. An example will be described, but it is not necessarily limited thereto. For example, the suction-side sealing part and the discharge-side sealing part, which will be described later, can be equally applied to a single-sided turbocompressor having at least one or more impellers provided at one end of a rotating shaft.

In addition, the turbo compressor according to the present embodiment will be described focusing on an example applied to a chiller system for supplying cold water to a customer, but the scope of application is not necessarily limited to the chiller system. For example, the turbo compressor according to the present embodiment may be equally applied to a refrigeration cycle system using a refrigerant.

In addition, in the turbo compressor according to the present embodiment, the longitudinal direction of the rotating shaft is defined as the axial direction and the thickness direction of the rotating shaft is defined as the radial direction, respectively, and the suction side of each impeller (or compression unit) is forward on the axial line, each The discharge side of the impeller is defined as the rear side, respectively, the front side is defined as the first side, and the rear side is defined as the second side.

1 is a schematic diagram showing a refrigeration cycle including a turbo compressor according to the present embodiment.

Referring to Figure 1, the refrigeration cycle apparatus to which the turbo compressor according to the present embodiment is applied, the compressor 10, condenser 20, expander 30, evaporator 40 is configured to form a closed loop. That is, the condenser 20, the expander 30, and the evaporator 40 are sequentially connected to the discharge side of the compressor 10, and the outlet of the evaporator 40 is connected to the suction side of the compressor 10. Accordingly, the refrigerant compressed in the compressor 10 is discharged toward the condenser 20, and the refrigerant passes through the expander 30 and the evaporator 40 in turn and is sucked back into the compressor 10, repeating a series of processes. .

2 is a perspective view showing an exploded turbocompressor according to the present embodiment, FIG. 3 is a perspective view showing an inside after assembling the turbocompressor according to FIG. 2, and FIG. 4 is a cross-sectional view showing the inside of the turbocompressor according to FIG. 3 , FIG. 5 is an enlarged cross-sectional view of the first compression unit in FIG. 4 , and FIG. 6 is an enlarged cross-sectional view of the second compression unit in FIG. 4 .

Referring to these drawings, the turbo compressor 10 according to the present embodiment includes a housing 110, a transmission unit 120 constituting a driving motor, a rotating shaft 130, a bearing unit 140, a first compression unit (1 stage) compression unit) 150, a second compression unit (two-stage compression unit) 160, and a refrigerant passage unit 170.

2 to 4, the housing 110 according to the present embodiment forms the appearance of the turbo compressor 10, and includes a motor housing 111, a first impeller housing 112, and a second impeller housing ( 113).

The motor housing 111 may be formed in a cylindrical shape with open ends in the axial direction. However, both ends of the motor housing 111 have a first flange portion 1111 and a second flange portion 1112 extending in the radial direction so as to be fastened with the first impeller housing 112 and the second impeller housing 113 to be described later. A depression 1113 in which the outer circumferential surface at the center of the motor housing 111 is depressed may be formed between the first flange portion 1111 and the second flange portion 1112 . Accordingly, both ends of the motor housing 111 are formed thickly to ensure fastening strength, while the center side is formed thinly so that motor heat generated in the transmission unit 120 can be quickly dissipated.

The first flange portion 1111 is formed in an annular shape, and a bearing shell seating groove 1111a into which a part of the first bearing shell 142 to be described later is inserted is formed therein, and an inner circumferential surface of the bearing shell seating groove 1111a is formed. A radially stepped bearing shell seating surface 1111b may be formed. A bearing support part 1115 to be described later may be formed extending in a radial direction from one side of the bearing shell seating surface 1111b. The bearing support 1115 will be described again later.

The depth of the bearing shell seating groove 1111a may be substantially the same as or slightly shallower than the thickness of the first bearing shell 142 . Accordingly, a part of the first side surface 142a side of the first bearing shell 142 seated on the bearing shell seating surface 1111b is inserted into the bearing shell receiving groove 112a provided in the first impeller housing 112 to be described later. and can be supported in the radial direction.

The second flange portion 1112 may be formed similarly to the first flange portion 1111 around the stator 121 as a whole. However, the second side surface 146a of the second bearing shell 146, which will be described later, may be fastened in close contact with the end surface of the second flange portion 1112.

A motor room 1114 is formed inside the motor housing 111 . In the motor room 1114, a stator 121 to be described later is shrink-fitted and press-fitted to the center thereof. Accordingly, the motor chamber 1114 has a first chamber 1114a on the side of the first compression unit 150 and a second chamber on the side of the second compression unit 160 based on the stator 121 to be described later. ) (1114b).

The first space 1114a is opened toward the first compression unit 150 and sealed by the first impeller housing 112, more precisely, the first bearing shell 142, and the second space 1114b is the second compression space 1114b. It is opened toward the part 160 but can be sealed by the second impeller housing 113, more precisely, the second bearing shell 146. The first space 1114a and the second space 1114b are the gap between the stator core 1211 and the stator coil 1212 constituting the stator 121 of the transmission unit 120 or the stator 121 and the rotor 122 ) are substantially in communication with each other through the gap between them. Accordingly, the refrigerant in the motor chamber 1114 can move smoothly between both spaces 1114a and 1114b according to the pressure difference.

A bearing support part 1115 constituting a part of a first bearing part 141 to be described later may be formed in the middle of the first space 1114a. Accordingly, the first space 1114a may be divided into a motor accommodating space 1114a1 and a bearing accommodating space 1114a2 centered on the bearing support 1115 .

Referring to FIGS. 4 and 5 , the bearing support 1115 may extend radially from the inner circumferential surface of the motor housing 111 constituting the first space 1114a toward the rotation shaft 130 . However, the bearing support 1115 may be pressed into the inner circumferential surface of the motor housing 111 or may be fastened using a fastening member (not shown) such as a bolt. An example in which the bearing support part 1115 according to the present embodiment extends from the inner circumferential surface of the motor housing 111 as a single unit is shown.

As the bearing support part 1115 is formed in the first space 1114a, the stator 121 moves from the second flange part (second end) 1111 of the motor housing 111 to the first flange part (first end) ( 1112) may be pressed in the direction. Accordingly, a stator fixing jaw (not marked) is formed on the inner circumferential surface of the motor housing 111 forming the end of the first space 1114a, so that the press-in depth of the stator 121 can be limited.

Although not shown in the drawing, when the bearing support 1115 is formed in the second space 1114b, the stator 121 may be press-fitted from the first flange 1111 toward the second flange 1112. In this case, a stator fixing step (not shown) may be formed on the inner circumferential surface of the motor housing 111 forming the end of the second space 1114b.

In addition, although not shown in the drawing, when the bearing support 1115 is post-assembled, the stator 121 can be press-fitted in either direction. In this case, the stator 121 may be fixed using the bearing support 1115 .

The bearing support 1115 may be formed in an annular disk shape. For example, a first through hole 1115c penetrating both side surfaces 1115a and 11115b in the axial direction may be formed at the center of the bearing support part 1115 . In the first through hole 1115c, a first radial bearing 143, which will be described later, is provided on the rotational shaft 130 to support an end portion of the rotational shaft 130 on the side of the first compression unit in the radial direction.

The first through hole 1115c has an inner diameter through which the rotation shaft 130 can pass. For example, the first through hole 1115c is larger than the outer diameter of the first impeller shaft portion 132 to be described later and smaller than the outer diameter of the thrust runner 1324 to be described later. Accordingly, when assembling the rotating shaft 130, the first impeller shaft portion 132 connects the first through hole 1115c of the bearing support portion 1115 to the first flange portion 1111 of the motor housing 111 to the second flange portion ( 1112), the second side surface 1324b of the thrust runner 1324 is axially supported by the first side surface 1115a of the bearing support 1115 facing it in the axial direction, which will be described later. A second axial bearing 1442 is formed. This will be explained later in the bearing section.

The bearing support part 1115 has a refrigerant through hole 1115d penetrating both sides in the axial direction between the first through hole 1115c forming the inner circumferential surface of the bearing support part 1115 and the root end forming the inner circumferential surface of the motor housing 111. can be formed A plurality of refrigerant through-holes 1115d may be formed along the circumferential direction. Accordingly, the motor accommodating space 1114a1 and the bearing accommodating space 1114a2 may communicate with each other by the first through hole 1115c and the refrigerant through hole 1115d.

The bearing accommodation space 1114a2 may be formed on the opposite side of the stator 121 with the bearing support 1115 as the center. The bearing accommodation space 1114a2 is the inner space of the first flange portion 1111 described above, that is, the inner circumferential surface of the bearing shell seating groove 1111a and the first side surface 1115a of the bearing support 1115 and the first impeller housing to be described later. (112).

The bearing accommodation space 1114a2 is entirely sealed except for the first through hole 1115c of the bearing support 1115, the refrigerant through hole 1115d, and the first shaft hole 142c of the first bearing shell 142, which will be described later. space can be formed. However, in this embodiment, a first inflow passage part 1711 to be described later may be formed to supply the liquid refrigerant that has passed through the condenser 20 to the bearing accommodation space 1114a2.

The first inlet passage part 1711 may be connected to the outlet side of the condenser 20 through the first refrigerant inlet pipe 1712 . Accordingly, the liquid refrigerant passing through the condenser 20 flows into the bearing accommodation space 1114a2 constituting a part of the first space 1114a, and the liquid refrigerant flows into the first bearing shell 142 provided on the inner circumferential surface. A radial bearing 143, a first axial bearing 1441 provided on the second side surface 142b of the first bearing shell 142, and a first provided on the first side surface 1115a of the bearing support 1115. It can be introduced into two axial bearings (1442). Accordingly, the liquid refrigerant, which is a working fluid, supports each of the bearings 143, 1441, and 1442 constituting the first bearing part 141 to secure a bearing force for the first compression part-side end of the rotary shaft 130, and at the same time Each of the bearings 143, 1441, and 1442 constituting the one-bearing unit 141 and the rotating shaft 130 facing them are cooled.

Meanwhile, the second space 1114b substantially communicates with the first space 1114a as described above. However, a second refrigerant inlet pipe 1716 to be described later may be connected to the motor housing 111 constituting the second space 1114b. The second refrigerant inlet pipe 1716 may be connected to the outlet side of the condenser 20 like the first refrigerant inlet pipe 1712 . Accordingly, a portion of the liquid refrigerant passing through the condenser 20 flows into the second space 1114b, and the liquid refrigerant may flow into the second radial bearing 147 communicating with the second space 1114b. . Accordingly, the liquid refrigerant, which is a working fluid, supports the bump foil constituting the second radial bearing 147 to secure a bearing force for the second end of the rotation shaft and at the same time cools the second radial bearing 147 and the rotation shaft facing the rotation shaft. will make

2 to 5, in the first impeller housing 112, the second side facing the motor housing 111 is in close contact with the first flange portion 1111 of the motor housing 111 and fastened with bolts, The first impeller housing 112 may be formed in a substantially disc shape.

A first sealing member 181 such as a gasket or an O-ring is provided between the second side surface of the first impeller housing 112 and the first flange portion 1111 of the motor housing 111 facing it, so that the motor housing 111 ) of the first space (1114a), more precisely, the bearing accommodation space (1114a2) can be tightly sealed.

For example, on the second side surface of the first impeller housing 112, a bearing shell receiving groove 112a is formed wider than the outer diameter of the first volute 1124 to be described later, and an annular shape is formed outside the bearing shell receiving groove 112a. The first housing fastening surface 112b of may be formed stepwise from the bearing shell receiving groove 112a. The first housing fastening surface 112b may be in close contact with the first flange portion 1111 of the motor housing 111 with the first sealing member 181 therebetween and fastened with bolts.

The first impeller housing 112 according to the present embodiment includes a first inlet 1121, a first impeller accommodating part 1122, a first diffuser 1123, a first volute 1124, and a first discharge port 1125. includes

The first inlet 1121 may be formed in a direction penetrating both side surfaces in the axial direction from the center of the first impeller housing 112 . For example, the first inlet 1121 may be opened from the front surface (first side surface) of the first impeller housing 112 and extend in the axial direction. The first inlet 1121 may be formed in a truncated cone shape with a wide inlet end to which the refrigerant suction pipe 115 is connected and a narrow outlet end to which the first impeller accommodating part 1122 is connected. Accordingly, the flow rate and flow rate of the refrigerant sucked through the first inlet 1121 may be increased.

The first impeller accommodating portion 1122 extends from the outlet end of the first inlet 1121 toward the outer circumferential surface of the first impeller 151, and the first impeller 151 is inside the first impeller accommodating portion 1122. It can be inserted rotatably. Accordingly, the first impeller accommodating portion 1122 may be defined as a first fixed-side shroud, and the inner circumferential surface of the first impeller accommodating portion 1122 may be formed to be curved along the shape of the outer surface of the first impeller 151. can

The first impeller accommodating portion 1122 may be formed so that its inner circumferential surface is spaced apart from the outer surface of the first impeller 151 by as little as possible an air gap. Accordingly, the refrigerant passing through the first impeller 151 passes through the air gap between the outside of the first impeller 151, that is, the inner circumferential surface of the first impeller accommodating portion 1122 and the outer circumferential surface of the first impeller 151. It is possible to block the reverse flow from the discharge side of 151 to the suction side. Through this, it is possible to suppress suction loss in the first compression unit, which occurs when the refrigerant compressed in the first stage flows backward to the suction side of the relatively low-temperature and low-pressure first impeller 151.

A first suction-side sealing portion 155 or a part of the first suction-side sealing portion 155 may be formed on an inner circumferential surface of the first impeller accommodating portion 1122 . For example, a first outer sealing portion 1551 constituting the first suction-side sealing portion 155 may be formed on an inner circumferential surface of the first impeller accommodating portion 1122 .

The first outer sealing portion 1551 is formed unevenly along the axial direction and may be formed as a labyrinth seal together with a first inner sealing portion 1552 to be described later. Accordingly, leakage of refrigerant from the discharge side to the suction side between the inner circumferential surface of the first impeller accommodating portion 1122 and the outer circumferential surface of the first impeller 151 can be more effectively suppressed. The first suction-side sealing portion 155 including the first outer sealing portion 1551 will be described later.

The first diffuser 1123 may extend from the downstream end of the first impeller accommodating part 1122 . For example, the first diffuser 1123 may be formed as a space between the first side surface 142a of the first bearing shell 142 and the second side surface (unsigned) of the first impeller housing 112 facing the first side surface 142a. there is.

The first diffuser 1123 may include spiral protrusions protruding at predetermined intervals along the circumferential direction from the first side surface 142a of the first bearing shell 142, excluding the spiral protrusions described above and first diffuser 1123. It may be formed only as a space between the bearing shell 142 and the first impeller housing 112 facing the bearing shell 142 . The pressure of the refrigerant passing through the first diffuser 1123 increases as it approaches the first volute 1124 due to centrifugal force.

The first volute 1124 may be formed by being connected to the downstream side of the first diffuser 1123 . For example, the first volute 1124 may be formed by being recessed at the axial rear surface of the first impeller housing 112 . The first volute 1124 may be formed in a ring shape to surround the outer circumferential side of the first diffuser 1123, and may have a cross-sectional area gradually increasing toward a first outlet 1125 to be described later.

The first discharge port 1125 may be formed through the outer surface of the first impeller housing 112 in the middle of the first volute 1124 in the circumferential direction. Accordingly, the inlet end of the first outlet 1125 is connected to the first volute 1124, while the outlet end is connected to the second inlet of the second impeller housing 113 through the refrigerant connection pipe 116 to be described later. can

4 and 6, the second impeller housing 113 has a second side facing the motor housing 111 in close contact with the second flange portion 1112 of the motor housing 111, and the first impeller housing 112 is inserted into the motor housing 111 and fastened, while the second impeller housing 113 may be closely attached to the end surface of the motor housing 111 and fastened thereto. Accordingly, the outer diameter of the second impeller housing 113 may be larger than the inner diameter of the motor housing 111 .

The second impeller housing 113 may be formed substantially similar to the first impeller housing 112 . For example, the second impeller housing 113 according to this embodiment includes a second inlet 1131, a second impeller accommodating part 1132, a second diffuser 1133, a second volute 1134, a second An outlet 1135 may be included. The second inlet 1131 includes the first inlet 1121, the second impeller accommodating part 1132 includes the first impeller accommodating part (which can be defined as a second fixed-side shroud) 1122, and the second diffuser. 1133 may be formed in the same way as the first diffuser 1123, the second volute 1134 in the first volute 1124, and the second outlet 1135 in the first outlet 1125. . The second impeller housing 113 is replaced with the description of the first impeller housing 112.

In addition, the second suction-side sealing part 165 or a part of the second suction-side sealing part 165 may be formed on the inner circumferential surface of the second impeller accommodating part 1132 . Accordingly, leakage of the refrigerant from the discharge side to the suction side between the inner circumferential surface of the second impeller accommodating portion 1132 and the outer circumferential surface of the second impeller 161 can be more effectively suppressed. The second suction-side sealing part 165 will be described again later.

Referring to FIGS. 2 to 4 , the transmission unit 120 according to the present embodiment includes a stator 121 and a rotor 122 .

The stator 121 includes a stator core 1211 press-fitted and fixed to the motor housing 111 and a stator coil 1212 wound around the stator core 1211 .

The stator core 1211 is formed in a cylindrical shape, and one end in the axial direction of the stator core 1211 may be axially supported by a stator fixing shoulder (not shown) provided on an inner circumferential surface of the motor housing 111 . On the inner circumferential surface of the stator core 1211, a plurality of teeth protrude in the radial direction with the slot therebetween along the circumferential direction.

The stator coil 1212 is wound on each tooth through slots. Accordingly, a circumferential gap is generated between both stator coils 1212 in the slot, and this circumferential gap is a refrigerant passage that communicates the first space 1114a and the second space 1114b of the motor housing 111 with each other. do.

The rotor 122 is rotatably spaced apart from the inner circumferential surface of the stator 121 inside the stator 121 . The rotor 122 includes a rotor core 1221 and a permanent magnet 1222, but the rotor core 1221 may be coupled to the rotation shaft 130 or omitted. When the rotor core 1221 is omitted, the permanent magnet 1222 may be attached to an outer circumferential surface of the rotation shaft 130 or mounted inside the rotation shaft 130 . This embodiment shows an example in which the permanent magnet 1222 is inserted into the rotating shaft 130 and a part of the rotating shaft forms the rotor core 1221 .

Referring to FIGS. 3 and 4 , the rotating shaft 130 according to the present embodiment includes a driving shaft part 131 , a first impeller shaft part 132 , and a second impeller shaft part 133 .

The drive shaft portion 131 is formed in a cylindrical shape and is rotatably inserted into the stator 121 . For example, the length of the drive shaft portion 131 is longer than or equal to the axial length of the stator 121, and the axial center of the drive shaft portion 131 is positioned on the same line as the axial center of the stator 121 in the radial direction. can be combined to

A magnet accommodating part 1311 is formed inside the driving shaft part 131 , and a permanent magnet 1222 constituting the rotor 122 is inserted into the magnet accommodating part 1311 . Accordingly, the driving shaft unit 131 forms a part of the rotor 122 together with the permanent magnet 1222 while forming a part of the rotating shaft 130 .

The magnet accommodating portion 1311 has substantially the same shape as the outer circumference of the permanent magnet 1222 , and the inner diameter of the magnet accommodating portion 1311 may be substantially the same as the outer diameter of the permanent magnet 1222 . Accordingly, the permanent magnet 1222 inserted into the magnet accommodating part 1311 can maintain its position in the magnet accommodating part 1311 as much as possible.

A magnet fixing jaw 1311a supporting one end of the permanent magnet 1222 in the axial direction may be formed stepwise on the inside of the drive shaft part 131, that is, on the inner circumferential surface of the magnet accommodating part 1311. Accordingly, when assembling the permanent magnet 1222, the permanent magnet 1222 is not only easily positioned at the center of the stator, but also the permanent magnet 1222 maintains its position at the center of the stator even when the rotating shaft 130 rotates at a high speed. can be kept stable.

Although not shown in the drawings, at least one or more magnet restraining parts (not shown) may be further formed between the inner circumferential surface of the magnet accommodating part 1311 and the outer circumferential surface of the permanent magnet 1222 facing the inner circumferential surface. The magnet restraining part may be formed to correspond to each other on the inner circumferential surface of the magnet accommodating part 1311 and the outer circumferential surface of the permanent magnet 1222 . For example, the magnet restraining part may be formed in a decut shape or formed of a restraining protrusion and a restraining groove extending in an axial direction.

The first impeller shaft portion 132 includes a first shaft fixing portion 1321 , a first impeller fixing portion 1322 , a first bearing surface portion 1323 , and a thrust runner 1324 .

The first shaft fixing part 1321 extends in the axial direction from the first bearing surface part 1323 toward the second impeller shaft part 133, and is smaller than the outer diameter of the first bearing surface part 1323. Accordingly, the first shaft fixing part 1321 may be inserted into and fixed to the first compression part side end (hereinafter referred to as first end) of the driving shaft part 131 . For example, the first shaft fixing part 1321 may be welded and coupled in a press-fitted state to the first end of the drive shaft part 131 . Although not shown in the drawings, between the first shaft fixing part 1321 of the first impeller shaft part 132 and the first end of the drive shaft part 131, there is a de-cut or protrusion and groove (or slit) anti-rotation part (unsigned). ) may be further formed.

The first impeller fixing part 1322 extends in an axial direction from the first bearing surface part 1323 toward the first impeller 151 opposite to the first shaft fixing part 1321 . The first impeller fixing part 1322 is formed smaller than the outer diameter of the first shaft fixing part 1321 as well as the first bearing surface part 1323 and is inserted into the first hub 1511 of the first impeller 151 to be described later. can be combined

The first impeller fixing part 1322 may be formed in an angular shape or a decut shape. Accordingly, in a state where the first impeller fixing part 1322 is inserted into the first impeller 151, the rotational force of the transmission part 120 can be transmitted without slip.

The first bearing surface portion 1323 is formed in a rod or cylindrical shape between the first shaft fixing portion 1321 and the first impeller fixing portion 1322 . The first bearing surface portion 1323 is inserted into a first radial bearing 143 to be described later and supported in the radial direction, and the outer circumferential surface of the first bearing surface portion 1323 rotates with respect to the first radial bearing 143. It may be formed smoothly into a smooth tube shape so that resistance does not occur.

3 to 5, the thrust runner 1324 extends between the first shaft fixing part 1321 and the first impeller fixing part 1322, that is, from the outer circumferential surface of the first bearing surface part 1323 in a flange shape. It can be formed into a disc shape.

The thrust runner 1324 may be provided between the bearing support 1115 and the first bearing shell 142 and supported in both axial directions between the bearing support 1115 and the first bearing shell 142 . In other words, the thrust runner 1324 forms an axially movable side support (movable side support), and the bearing support 1115 and the first bearing shell 142 each form an axially fixed side support (fixed side support). can Accordingly, the rotating shaft 130 may be supported in both axial directions together with the first impeller 151 and the second impeller 161 coupled to both ends of the rotating shaft 130 .

Here, the bearing support 1115 constituting the fixed side support and the first bearing shell 142 form a second space 1114b with the thrust runner 1324 interposed therebetween, so that the first bearing shell 142 has a first As a partition wall, the bearing support part 1115 may be defined as a second partition wall.

The thrust runner 1324 may be formed so that its outer circumferential surface is spaced apart from the inner circumferential surface of the bearing accommodating space 1114a2. The outer diameter of the thrust runner 1324 is smaller than the inner diameter of the bearing accommodating space 1114a2, and the outer circumferential surface of the thrust runner 1324 and the inner circumferential surface of the bearing accommodating space 1114a2 are separated by a predetermined distance in the radial direction. An air gap G1 may be formed.

The first air gap G1 may communicate with a second air gap G2 provided with a first axial bearing 1441 to be described later and a third air gap G3 provided with a second axial bearing 1442 described later. there is. In other words, the outer peripheral side of the second air gap G2 formed between the first side surface 1324a of the thrust runner 1324 and the second side surface 142b of the first bearing shell 142 facing the same is the first air gap G1 ), and the outer circumferential side of the third gap G3 formed between the second side surface 1324b of the thrust runner 1324 and the first side surface 1115a of the bearing support 1115 facing it is 1 may be in communication with the inner circumferential side of the gap G1.

Accordingly, the refrigerant flows into the first gap G1 constituting the bearing accommodating space 1114a2 through the first refrigerant inlet 1713 to be described later, and the refrigerant moves in the circumferential direction in the first gap G1 and It may flow into the second void G2 and the third void G3. The refrigerant is supplied to the first axial bearing 1441 and the second axial bearing 1442 in the radial direction while moving from the outer circumferential side to the inner circumferential side of the second air gap G2 and the third air gap G3, so that the first shaft The directional bearing 1441 and the second axial bearing 1442 can each maintain a uniform bearing force.

The first shaft hole 142c of the first bearing shell 142 constituting the fourth air gap G4 communicates with the inner circumferential side of the second air gap G2, and the bearing support part 1115 communicates with the inner circumferential side of the third air gap G3. The first through holes 1115c of may communicate with each other. Accordingly, the refrigerant moving from the outer circumferential side to the inner circumferential side of the second air gap G2 is introduced into the first shaft hole 142c, and the refrigerant is transferred to the first radial bearing 143 provided in the first shaft hole 142c. Is supplied from one end to the other end of the first radial bearing 143 can maintain a uniform bearing force.

Meanwhile, the refrigerant moving from the outer circumferential side to the inner circumferential side of the third air gap G3 passes through the first through hole 1115c and moves into the motor accommodating space 1114a1.

Although not shown in the drawing, the first axial bearing 1441 is on the first side surface 1324a of the thrust runner 1324, and the second axial bearing 1442 is on the second side surface 1324b of the thrust runner 1324. may be provided in each. In this case, as both the first axial bearing 1441 and the second axial bearing 1442 are installed on the rotating shaft 130, the first axial bearing 1441 and the second axial bearing 1442 are installed and Assembly can be easy. The first axial bearing 1441 and the second axial bearing 1442 will be described again later.

Referring to FIG. 4 , the second impeller shaft portion 133 may be inserted into and fixed to a second compression portion-side end (hereinafter referred to as a second end) of the drive shaft portion 131 . For example, the second impeller shaft portion 133 may be welded and coupled in a press-fitted state to the second end of the drive shaft portion 131 like the first impeller shaft portion 132 .

The second impeller shaft portion 133 is formed to be symmetrical about the first impeller shaft portion 132 and the drive shaft portion 131, but the second bearing portion 145 does not have an axial bearing, so the thrust runner 1324 ) can be excluded. That is, the second impeller shaft portion 133 may include a second shaft fixing portion 1331 , a second impeller fixing portion 1332 , and a second bearing surface portion 1333 . However, in some cases, an axial bearing may be provided in the second bearing part 145, and the thrust runner 1324 may be provided in the second impeller shaft part 133.

The bearing part 140 according to this embodiment includes a first bearing part 141 and a second bearing part 145 . The first bearing part 141 is between the transmission part (or drive motor) 120 and the first compression part 150, and the second bearing part 145 is between the transmission part (or drive motor) 120 and It may be provided between the two compression units 160, respectively.

4 and 5, the first bearing part 141 includes a first bearing shell 142, a first radial bearing 143, a first axial bearing 1441 and a second axial bearing 1442. ). The first radial bearing 143 is on the inner circumferential surface of the first bearing shell 142, the first axial bearing 1441 is on the second side surface 142b of the first bearing shell 142, the second axial bearing Numerals 1442 are located on the first side surface 1115a of the bearing support 1115, respectively.

The first bearing shell 142 may be bolted to the motor housing 111 between the bearing support 1115 and the first impeller housing 112 . For example, the first bearing shell 142 is inserted into the bearing shell seating groove 1111a of the motor housing 111, and the second side 142b of the first bearing shell 142, which is the opposite side of the first compression unit, is It is fastened with bolts in a state of close contact with the bearing shell seating surface (1111b).

However, in some cases, the fastening bolts are excluded, and both sides of the first bearing shell 142 are respectively connected to the bearing shell seating surface 1111b of the motor housing 111 and the impeller shell receiving groove of the first impeller housing 112 ( 112a) may be fixed in close contact. In this case, as a separate fastening member for fastening the first bearing shell 142 is excluded, the first bearing shell 142 can be easily assembled at low cost.

The first bearing shell 142 is formed in an annular shape, and the outer circumferential surface thereof may be depressed to have a substantially U-shaped cross-sectional shape. For example, the first bearing shell 142 may include an inner wall portion 1421 , a first side wall portion 1422 , a second side wall portion 1423 , and a refrigerant accommodating portion 1424 .

The inner wall portion 1421 is formed in an annular shape so as to surround the outer circumferential surface of the rotating shaft 130 in the circumferential direction, and the inner diameter of the inner wall portion 1421 may be larger than the outer diameter of the rotating shaft 130 . Accordingly, a first shaft hole 142c spaced apart from the outer circumferential surface of the rotating shaft 130 is formed on the inner circumferential surface of the inner wall portion 1421, and a first radial bearing 143 may be provided on the inner circumferential surface of the inner wall portion 1421. there is. The first radial bearing 143 may be formed of a gas foil bearing in the same manner as in the above-described embodiments.

The first side wall portion 1422 is an annular shape extending radially from one side of the outer circumferential surface of the inner wall portion 1421, to be precise, from the outer circumferential surface of the front side facing the first impeller 151 among both ends in the axial direction of the first side wall portion 1422. can be formed as

The outer diameter of the first side wall portion 1422 may be formed substantially similar to the inner diameter of the bearing shell receiving groove 112a provided in the first impeller housing 112 . Accordingly, the outer circumferential surface of the first side wall portion 1422 can be supported in the radial direction by being in close contact with the inner circumferential surface of the bearing shell receiving groove 112a. Through this, even when the first bearing shell 142 is bolted to the motor housing 111, the first bearing shell 142 can be stably supported while reducing the number of bolts. In addition, since the assembly position of the first bearing shell 142 can be determined using the bearing shell receiving groove 112a, manufacturing costs can be reduced by removing a separate reference pin.

A rear side sealing portion 1562 may be formed at the center of the front surface of the first side wall portion 1422 . The rear-side sealing part 1562 may form a first discharge-side sealing part 156 forming a labyrinth chamber together with a front-side sealing part 1561 to be described later. For example, the rear side sealing portion 1562 may be formed by alternately forming annular protrusions of a preset height and annular grooves of a preset depth in a radial direction.

The second side wall portion 1423 may extend in a radial direction from the other side of the outer circumferential surface of the inner wall portion 1421 to form an annular shape. The second side wall portion 1423 may be shorter than the first side wall portion 1422 . For example, the outer diameter of the second side wall portion 1423 may be smaller than the inner diameter of the motor housing 111 . Accordingly, a first air gap G1 may be formed between the outer circumferential surface of the second side wall portion 1423 and the inner circumferential surface of the motor housing 111 facing the outer circumferential surface in the radial direction.

However, in some cases, the outer diameter of the second side wall portion 1423 may be substantially the same as the inner diameter of the motor housing 111 . In this case, a separate refrigerant passage (not shown) having at least one hole or groove may be formed in the second side wall portion 1423 .

The coolant accommodating part 1424 may be formed between the first side wall part 1422 and the second side wall part 1423 . Specifically, the refrigerant accommodating portion 1424 is defined as a space formed in an annular shape by the outer circumferential surface of the inner wall portion 1421, the second side surface of the first side wall portion 1422, and the first side surface of the second side wall portion 1423. It can be. Accordingly, the inner circumferential side of the refrigerant accommodating portion 1424 facing the rotating shaft 130 may be sealed by the inner wall portion 1421, and at least a portion of the outer circumferential side facing the inner circumferential surface of the motor housing 111 may be opened.

The refrigerant accommodating part 1424 may be formed to overlap with the first refrigerant inlet 1713 in the radial direction. For example, the outlet of the first refrigerant inlet 1713 may be located between the first side wall portion 1422 and the second side wall portion 1423 .

Meanwhile, a refrigerant introduction passage 1714 may be formed in the inner wall portion 1421 .

The refrigerant inflow passage 1714 may be formed of a single passage with one inlet and one outlet, or a double passage with one inlet and a plurality of outlets. The refrigerant inflow passage according to the present embodiment shows an example of a double passage.

For example, the refrigerant inflow passage 1714 may include a first inflow passage 1714a and a second inflow passage 1714b with separated outlets. The inlet of the first inlet passage 1714a and the inlet of the second inlet passage 1714b may communicate with each other and open toward the refrigerant accommodating part 1424 at the middle of the outer circumferential surface of the inner wall part 1421 . An outlet of the first inflow passage 1714a may open to the second side surface 142b of the inner wall portion 1421, and an outlet of the second inflow passage 1714b may open to an inner circumferential surface of the inner wall portion 1421.

Although not shown in the drawing, the outlet of the first inflow passage 1714a may be formed to open to the side of the second side wall portion 1423 extending from the inner wall portion 1421 . However, this is a difference according to specifying the ranges of the inner wall portion 1421 and the second side wall portion 1423, and substantially, the outlet of the first inlet passage 1714a is the inner wall portion 1421 facing the thrust runner 1324. It can also be said that it is opened to the side of .

The refrigerant inlet passage 1714 may be formed only one, or may be formed in plurality along the circumferential direction at predetermined intervals. In this embodiment, an example in which a plurality of refrigerant introduction passages 1714 are formed at equal intervals along the circumferential direction of the inner wall portion 1421 is shown. Accordingly, while the refrigerant is uniformly supplied to each bearing through the plurality of refrigerant inlet passages 1714, the refrigerant is uniformly supplied to the first radial bearing 143 and the first and second axial bearings 1441 and 1442. can supply Through this, the rotation shaft 130 can be stably supported by uniformly maintaining the bearing force of the first axial bearing 143 and the first and second axial bearings 1441 and 1442 .

When the refrigerant accommodating portion 1424 is formed in an annular shape on the outer circumferential surface of the first bearing shell 142 as in the present embodiment, the refrigerant flowing into the bearing accommodating space 1114a2 flows into the refrigerant accommodating portion of the first bearing shell 142. It is directly introduced into the refrigerant 1424 and received therein, and the refrigerant can be evenly distributed throughout the refrigerant accommodating portion 1424 while moving in the circumferential direction. Accordingly, the first bearing shell 142 including the refrigerant accommodating portion 1424 can be quickly and evenly cooled by the refrigerant accommodated in the refrigerant accommodating portion 1424 .

In addition, as the refrigerant accommodating portion 1424 is formed to be depressed by a predetermined depth from the outer circumferential surface to the inner circumferential surface of the first bearing shell 142, the first inlet passage 1714a or the first inlet passage 1714a forming the outlet of the refrigerant inlet passage 1714 is formed. 2 The inlet passage 1714b may be processed to be inclined. Accordingly, the mass flow of the refrigerant can be increased by forming the outlet of the refrigerant inflow passage 1714 to be adjacent to the rotational shaft 130 as much as possible.

In addition, as the outlet of the refrigerant inlet passage 1714 is formed to be adjacent to the rotation shaft 130 as much as possible, the radial length of the first axial bearing 1441 is increased while securing the radial thickness of the inner wall portion 1421. can do. Through this, the bearing force of the first axial bearing 1441 can be secured.

On the other hand, forming a part of the first discharge-side sealing portion 156 on the front surface of the first bearing shell 142, that is, on the first side surface 142a of the first side wall portion 1422 facing the first impeller 151. A rear side sealing portion 1562 may be provided. The rear side sealing portion 1562 may be formed of at least one concave-convex annular labyrinth seal along a radial direction. Accordingly, the first discharge-side sealing portion 156 including the rear-side sealing portion 1562 forms a radial sealing portion.

In this case, the first discharge-side sealing part 156 may be formed only of the rear-side sealing part 1562, and the rear-side sealing part 1562 is a front-side sealing part on the rear surface of the first impeller 151 facing in the axial direction. A portion 1561 may be provided and formed by a combination of the front side sealing portion 1561 and the rear side sealing portion 1562.

For example, when the first discharge-side sealing part 156 is formed of a combination of the front-side sealing part 1561 and the rear-side sealing part 1562, the protrusion of the front-side sealing part 1561 is the rear-side sealing part 1562. ), both sealing parts 1561 and 1562 may be formed symmetrically with each other so that the protrusions of the rear sealing part 1562 are inserted into the groove of the front sealing part 1561 by a predetermined depth. Accordingly, as the first discharge-side sealing portion 156 is formed in a zigzag shape and the sealing passage is formed narrow and long, the refrigerant flows through the gap between the front surface of the first bearing shell 142 and the rear surface of the first impeller 151. Leakage to the motor room 1114 can be suppressed.

The first discharge-side sealing part 156 including the rear-side sealing part 1562 may be formed at a position overlapping with the first impeller 151 in the axial direction. Accordingly, the refrigerant passing through the first impeller 151 and the first diffuser 1123 is transferred to the rear surface (second side surface) of the first impeller 151 and the front surface (first side surface) of the first bearing shell 142. ), it is possible to increase the compression efficiency by minimizing leakage through the gap between them.

However, in this case, the refrigerant, which is a working fluid, is not sufficiently supplied to the first radial bearing 143 and the first and second axial bearings 1441 and 1442, which will be described later, so that the bearing force formation of each bearing is delayed or overheated. can Accordingly, as in the present embodiment, a refrigerant passage to be described later may be separately formed in the first radial bearing 143 and the first and second axial bearings 1441 and 1442 to supply refrigerant to each bearing. Through this, it is possible to increase the reliability of the bearings 143, 1441, and 1442 and suppress overheating while increasing compression efficiency by reducing refrigerant leakage in the first compression unit 150. This will be explained again later.

The first bearing shell 142 is provided with a first radial bearing 143 to be described later on the inner circumferential surface of the first shaft hole 142c, and the second of the first bearing shell 142 facing the thrust runner 1324. A first axial bearing 1441 may be provided on the side surface 142b.

Although not shown in the drawings, the first radial bearing 143 is on the outer circumferential surface (first bearing surface portion) of the rotating shaft 130, and the first axial bearing 1441 is on the first side surface 142a of the thrust runner 1324. may be provided in each.

The first radial bearing 143 may be made of a gas foil bearing. For example, the first radial bearing 143 may be formed of a concave-convex bump foil (unsigned) and an arc-shaped top foil (unmarked).

The first radial bearing 143 may be provided on the inner circumferential surface of the first bearing shell 142 so as to radially face the outer circumferential surface of the rotating shaft 130 , precisely the first bearing surface portion 1323 . Accordingly, when the rotary shaft 130 rotates, the refrigerant, which is a working fluid, is introduced into the first radial bearing 143 to form a kind of oil film and support the rotary shaft 130 in the radial direction. Since the gas foil bearing is commonly known, a detailed description thereof will be omitted.

However, in the first radial bearing 143 according to the present embodiment, the bump foil protrudes convexly in the radial direction and is formed irregularly along the circumferential direction, and the top foil is formed by a predetermined interval with respect to the outer circumferential surface of the rotating shaft 130. can be separated Accordingly, the first radial bearing 143 may be formed with an axial refrigerant passage in which both ends in the axial direction are opened.

Therefore, in this embodiment, the refrigerant inlet passage 1714 to be described later may be formed to be located outside the axial range of the first radial bearing 143. Accordingly, the refrigerant introduced into the bearing accommodating space 1114a2 is introduced from one axial end to the other end of the first radial bearing 143, so that the oil film between the rotary shaft 130 and the first radial bearing 143 is evenly distributed. can be formed The refrigerant inlet passage 1714 will be described later in the refrigerant passage section.

As described above, the first axial bearing 1441 may be fixedly installed on the second side surface 142b of the first bearing shell 142 . The first axial bearing 1441 is formed in a disk shape, and may be formed of a gas foil bearing similarly to the first radial bearing 143.

For example, the first axial bearing 1441 is composed of a concave-convex first pump foil (unsigned) and an arc plate-shaped first top foil (unsigned), and the second part of the first bearing shell 142 The side surface 142b may be disposed to face the first side surface 1324a of the thrust runner 1324. Even in this case, since the gas foil bearing is commonly known, a detailed description thereof will be omitted.

However, in the first axial bearing 1441 according to the present embodiment, the first bump foil (unsigned) protrudes convexly in the axial direction and is formed unevenly along the circumferential direction, and the first top foil (unmarked) is It may be spaced apart from the thrust runner 1324 by a predetermined interval. Accordingly, a radial refrigerant passage having both ends opened in the radial direction of the first axial bearing 1441 may be formed.

Accordingly, in this embodiment, the refrigerant inlet passage 1714 to be described later may be formed to be located outside the radial range of the first axial bearing 1441 . Through this, the refrigerant flowing into the bearing accommodating space 1114a2 flows from one radial end to the other end of the first axial bearing 1441, and the first side surface 1324a of the thrust runner 1324 and the first axial bearing ( 1441) can be evenly formed.

The second axial bearing 1442 is different from the first axial bearing 1441 only in its installation position, but has the same basic configuration and consequential effect. For example, the second axial bearing 1442 may be provided on the first side surface 1115a of the bearing support 1115 facing the second side surface 1324b of the thrust runner 1324. Accordingly, an oil film between the second side surface 1324b of the thrust runner 1324 and the second axial bearing 1442 can be evenly formed by the refrigerant flowing into the bearing accommodating space 1114a2.

Referring to FIGS. 4 and 6 , the second bearing part 145 according to the present embodiment includes a second bearing shell 146 and a second radial bearing 147 . The second radial bearing 147 may be provided in the second shaft hole 146c forming the inner circumferential surface of the second bearing shell 146 .

The second bearing shell 146 may be provided between the motor housing 111 and the second impeller housing 113 . For example, the first side surface 146a of the second bearing shell 146 facing the second compression unit 160 has the second sealing member 182 between it and the second impeller housing 113 in the axial direction. The second side surface 146b of the second bearing shell 146 opposite to the second side surface 146b may be fastened in close contact with the third sealing member 183 between the second flange portion 1112 of the motor housing 111, respectively. . Although not shown in the drawings, the second bearing shell 146 may be inserted into the second flange portion 1112 of the motor housing 111 and pressed and fixed to the motor housing 111 and the second impeller housing 113 . In this case, the assembly process for the second bearing shell 146 can be simplified by excluding a separate fastening member for fastening the second bearing shell 146 .

The second bearing shell 146 may be formed in an annular shape with an inner circumferential surface and an outer circumferential surface blocked. For example, the second bearing shell 146 may have a predetermined axial length and may be formed in an annular shape through which a second shaft hole 146c is axially penetrated at the center.

The inner diameter of the second shaft hole 146c may be larger than the outer diameter of the second bearing surface part 1333 provided on the rotating shaft 130, more precisely, the second impeller shaft part 133. Accordingly, the front end of the second impeller shaft portion 133 constituting the rotational shaft 130 may pass through the second shaft hole 146c of the second bearing shell 146 and be coupled to the second impeller 161 to be described later. .

A second discharge-side sealing portion 166 may be provided on an inner circumferential surface of the second shaft hole 146c. The second discharge-side sealing portion 166 may be formed of a labyrinth seal in which annular grooves are formed at predetermined intervals along the axial direction. Accordingly, the refrigerant passing through the second diffuser 1133 via the second impeller 161 passes through the fifth air gap G5 between the outer circumferential surface of the second impeller shaft portion 133 and the inner circumferential surface of the second bearing shell 146. It is possible to increase compression efficiency by minimizing leakage into the motor chamber 1114 .

A second radial bearing 147 may be provided on one side of the second discharge-side sealing portion 166, that is, on a side adjacent to the transmission unit 120 on the inner circumferential surface of the second shaft hole 146c. The second radial bearing 147 may be made of the same gas foil bearing as the first radial bearing 143 . For the second radial bearing 147, it is replaced with the description of the first radial bearing 143.

However, as described above, the second radial bearing 147 is injected into the motor room 1114 as it is provided to communicate with the motor room (exactly, the second space) 1114 on the side facing the motor room 1114. The liquid refrigerant may be directly supplied to the second radial bearing 147. Accordingly, the second compression unit 160 and the motor chamber (more precisely, the second space) 1114 are sealed by the second discharge-side sealing unit 166 to increase compression efficiency in the second compression unit 160 and , The second radial bearing 147 quickly secures a bearing force by the refrigerant flowing into the second space 1114b, and at the same time, the second radial bearing 147 and the rotating shaft 130 can be cooled.

Referring to FIGS. 4 and 5 , the first compression unit 150 according to the present embodiment includes a first impeller 151 , a first diffuser 1123 , and a first volute 1124 . However, among the components constituting the first compression unit 150, the first diffuser 1123 and the first volute 1124 are the same as those described above for the first impeller housing 112. That is, the first diffuser 1123 may be formed between the first impeller housing 112 and the first bearing shell 142 , and the first volute 1124 may be formed in the first impeller housing 112 . Therefore, the first compression unit 150 in the following description will be centered on the first impeller 151 .

The first impeller 151 includes a first hub 1511, a first blade, and a first shroud. As described above, the first impeller 151 together with the first diffuser 1123 and the first volute 1124 form the first compression unit 150, which is functionally a first stage compression unit. Accordingly, the suction side of the first impeller 151 is connected to the refrigerant suction pipe 115, and the discharge side of the first impeller 151 is the suction side of the second impeller 161 forming part of the two-stage compression unit (second compression unit). It can be connected to the refrigerant connection pipe 116.

The first hub 1511 is coupled to the rotating shaft 130 to receive rotational force, and the center of the first hub 1511 is inserted into the first impeller shaft portion 132 of the rotating shaft 130 to be coupled.

The first hub 1511 may be formed to have the same outer diameter in the axial direction, but may be formed in a truncated cone shape in which the outer diameter increases from the front to the rear, as in the present embodiment. Accordingly, the refrigerant can be compressed while smoothly moving from front to rear along the outer circumferential surface of the first hub 1511 .

A front side sealing portion 1561 forming a part of the first discharge side sealing portion 156 described above may be formed on one side of the first hub 1511, that is, on a second side facing the first bearing shell 142. there is.

The front side sealing portion 1561 may be formed to form a labyrinth seal by being concavo-convexly coupled to the rear side sealing portion 1562 provided on the first side surface 142a of the first bearing shell 142. Accordingly, leakage of the refrigerant passing through the first diffuser 1123 into the first space 1114a constituting the motor chamber 1114 can be suppressed.

The first blade 1512 may include a plurality of blades spaced apart at equal intervals along the circumferential direction of the first hub 1511 . The first blade 1512 composed of a plurality of blades extends in a radial direction from the outer circumferential surface of the first hub 1511 and may be spirally formed along an axial direction. Accordingly, the refrigerant sucked in the axial direction through the first inlet 1121 of the first impeller housing 112 passes through the first blade 1512 of the first impeller 151 while being helically wound around the first diffuser 1513. ) will move towards Through this, the flow rate of the refrigerant passing through the first diffuser 1513 is further increased, so that the first pressure in the first compression unit 150 can be further increased.

The first shroud 1513 may be formed to surround an outer surface of the first blade 1512 . For example, the first shroud 1513 may be formed in a hollow cylindrical shape, but may be formed in a truncated cone shape to correspond to an imaginary shape connecting the outer surface of the first blade 1512 .

The first shroud 1513 may be formed as a single body extending from the outer surface of the first blade 1512 using 3D printing or powder metallurgy, or may be manufactured separately and then assembled. In this embodiment, an example of post-assembling and welding the first shroud 1513 is shown. Although not shown in the drawing, the first shroud 1513 may surround only a portion of the first blade 1512 or may be formed on the current side of the first blade 1512 .

Referring to FIGS. 4 and 5 , the first shroud 1513 may include a first inlet portion 1513a and a first outlet portion 1513b.

The first inlet portion 1513a may be formed in a cylindrical shape with a single diameter, and the first outlet portion 1513b may be formed in a conical shape with multiple diameters. The first end of the first outlet part 1513b may be connected to the second end of the first inlet part 1513a to be formed as a single body.

The inner circumferential surface of the first inlet portion 1513a is formed in a smooth tube shape, and the first inner sealing portion 1552 constituting the first suction-side sealing portion 155 described above is formed on the outer circumferential surface of the first inlet portion 1513a. can be formed

The first inner sealing portion 1552 is formed unevenly along the axial direction and may be formed as a labyrinth seal together with the first outer sealing portion 1551 described above. The first suction-side sealing portion 155 including the first inner sealing portion 1552 will be described later.

The first outlet part 1513b may be formed in a smooth tube shape with smooth inner and outer circumferential surfaces. However, in some cases, an annular protrusion like the first inner sealing part 1552 described above may be formed on the outer circumferential surface of the first outlet part 1513b. In this case, an annular groove similar to that of the first outer sealing portion 1551 described above may be formed on the inner circumferential surface of the impeller accommodating portion 1122 of the first impeller housing 112 facing the first outlet portion 1513b. In this case, the first inner sealing portion 1552 and the first outer sealing portion 1551 are formed inclined with respect to the axial direction to form an inclined labyrinth seal. Accordingly, the refrigerant compressed in the first stage in the first impeller 151 flows backward through the air gap between the first impeller 151 and the first impeller housing 112 due to the pressure difference and more effectively suppresses leakage. can do.

Referring to FIGS. 4 and 6 , the second compression unit 160 according to the present embodiment includes a second impeller 161 , a second diffuser 1133 , and a second volute 1134 . However, among the components forming the second compression unit 160, the second diffuser 1133 and the second volute 1134 are the same as those described above for the second impeller housing 113. That is, the second diffuser 1133 may be formed between the second impeller housing 113 and the second bearing shell 146, and the second volute 1134 may be formed in the second impeller housing 113. Therefore, the second compression unit will be described below with a focus on the second impeller 161 .

The second impeller 161 includes a second hub 1611 , a second blade 1612 , and a second shroud 1613 . As described above, the second impeller 161 together with the second diffuser 1133 and the second volute 1134 functionally form a two-stage compression unit. Accordingly, the suction side of the second impeller 161 is connected to the discharge side of the first impeller 151 by the refrigerant connection pipe 116, and the discharge side of the second impeller 161 is connected to the condenser 20 by the refrigerant discharge pipe 117. It can be connected to the inlet side of.

The second impeller 161 is smaller than the diameter of the first impeller 151, but the overall shape may be substantially the same as that of the first impeller 151. Accordingly, the shape of the second impeller 161 is replaced with the description of the first impeller 151.

For example, the second suction side sealing portion 165 may be formed on the outer circumferential surface of the second impeller 161 and the inner circumferential surface of the second impeller accommodating portion 1132 of the second impeller housing 113 facing the outer circumferential surface. The second suction side sealing part 165 includes a second outer sealing part 1651 provided on the inner circumferential surface of the second impeller accommodating part 1132 and a second inner sealing part provided on the outer circumferential surface of the second impeller 161 ( 1652). However, as the second discharge-side sealing part 166 according to this embodiment is formed between the second bearing shell 146 and the rotating shaft 130, the second side of the second impeller 161 has a first impeller 151 ), the sealing portion may not be formed.

2 to 6, the refrigerant passage part 170 according to the present embodiment includes an inlet passage part 171, an outflow passage part 172, and a connection passage part 173. The inflow passage part 171 is a passage for guiding the refrigerant from the refrigerating cycle device to the motor chamber 1114 of the motor housing 111, and the outflow passage part 172 transfers the refrigerant from the motor chamber 1114 to the motor housing 111. is a passage for discharging to the outside, and the connection passage part 173 is a passage for guiding the refrigerant discharged from the motor housing 111 to the second compression unit 160 or the first compression unit 150 according to the operation mode.

The inflow passage part 171 may include a first inflow passage part 1711 and a second inflow passage part 1715 . The first inlet passage part 1711 guides the refrigerant to the first space 1114a of the motor housing 111 and the second inlet passage part 1715 to the second space 1114b of the motor housing 111, respectively. is a passage Accordingly, the first inflow passage portion 1711 and the second inflow passage portion 1715 may be formed as parallel conduits branched from one inlet to a plurality of outlets, or in series having different inlets and outlets independently. It may also consist of a conduit. This embodiment will be described taking a parallel type conduit as an example.

For example, the inlet end of the first inflow passage part 1711 and the inlet end of the second inflow passage part 1715 are branched from the outlet of the condenser 20 and connected in parallel, and the outlet of the first inflow passage part 1711 The ends may be independently connected to the first space 1114a of the motor housing 111 and the outlet end of the second inlet passage 1715 may be independently connected to the second space 1114b of the motor housing 111 . Accordingly, the liquid refrigerant passing through the condenser 20 is injected into the first space 1114a through the first inlet passage part 1711 and into the second space 1114b through the second inlet passage part 1715 ( can be injected).

Referring to FIGS. 4 and 5 , the first inflow passage part 1711 may include a first refrigerant inlet pipe 1712 , a first refrigerant inlet 1713 , and a refrigerant inlet passage 1714 .

The first refrigerant inlet pipe 1712 has one end branched with a second refrigerant inlet pipe 1716 to be described later at the middle of the refrigerating cycle device, that is, at the outlet of the condenser 20, and the other end of the first refrigerant inlet pipe 1714 of the motor room 1114. It may be inserted into and coupled to the first refrigerant inlet 1713 penetrating between the outer and inner circumferential surfaces of the motor housing 111 constituting the space 1114a.

The first refrigerant inlet pipe 1712 may be formed smaller than or equal to the inner diameter of the refrigerant circulation pipe constituting the refrigeration cycle device, that is, the refrigerant circulation pipe between the condenser 20 and the expander 30. Accordingly, excessive flow of refrigerant circulating through the refrigerating cycle device into the motor housing 111 of the compressor 10 can be suppressed.

One end of the first refrigerant inlet 1713 may be connected to the first refrigerant inlet pipe 1712 , and the other end of the first refrigerant inlet 1713 may be connected to the refrigerant inlet passage 1714 . Accordingly, the first refrigerant inlet pipe 1712 and the first refrigerant inlet 1713 may communicate with the first space 1114a of the motor housing 111 .

For example, the inlet end of the refrigerant inlet passage 1714 is opened to the outer circumferential surface of the first bearing shell 142 at least partially overlapping the first bearing shell 142 in the radial direction, and the refrigerant inlet passage 1714 The other end of ) may be opened to the second side surface 142b facing the thrust runner 1324 among both side surfaces of the first bearing shell 142 . Accordingly, the refrigerant flowing into the refrigerant inlet passage 1714 through the first refrigerant inlet pipe 1712 and the first refrigerant inlet 1713 passes through the first bearing shell 142 and the first bearing shell 142. will cool down Through this, it is possible to suppress overheating of the first radial bearing 143 and the first axial bearing 1441 provided in the first bearing shell 142 .

The refrigerant inlet passage 1714 may be formed in the shape of a single hole having substantially the same inner diameter between both ends. Accordingly, the refrigerant introduction passage 1714 can be easily formed and the refrigerant can be quickly injected into a desired position of the bearing accommodating space 1114a2.

The outlet end of the refrigerant inlet passage 1714 is open to the second side surface 142b of the first bearing shell 142, and the outlet end of the refrigerant inlet passage 1714 is located within the radial range of the thrust runner 1324. can be formed

For example, the outlet end of the refrigerant inlet passage 1714 has at least a portion of the first gap G1 formed between the inner circumferential surface of the motor housing 111 and the outer circumferential surface of the thrust runner 1324 facing the radial direction. It overlaps in the axial direction but may be formed at a position that does not overlap in the axial direction with the first axial bearing 1441. In other words, the outlet end of the refrigerant inflow passage 1714 may be formed to be located outside the radial range of the first axial bearing 1441 . Accordingly, the refrigerant injected into the bearing receiving space 1114a2 is supplied to the outer circumferential side of the first axial bearing 1441, and the refrigerant passes through the inside of the first axial bearing 1441 from the outer circumferential side to the inner circumferential side. It is possible to uniformly secure the bearing force of one axial bearing (1441).

Also, the first inflow passage portion 1711 may be formed to be equal to or larger than the second inflow passage portion 1715 . In other words, the cross-sectional area of the pipe of the first inflow passage portion 1711 may be formed to be the same as the cross-sectional area of the pipe of the second inflow passage portion 1715, but the cross-sectional area of the pipe of the first inflow passage portion 1711 is the second inflow passage portion. (1715) may be formed larger than the cross-sectional area of the pipe.

For example, the inner diameter of the first refrigerant inlet pipe 1712 constituting the first inflow passage portion 1711 or the inner diameter of the first refrigerant inlet port 1713 is the second refrigerant constituting the second inflow passage portion 1715 to be described later. It may be formed larger than the inner diameter of the inlet pipe 1716 or the inner diameter of the second refrigerant inlet 1717. Accordingly, a large amount of liquid refrigerant is introduced toward the first space 1114a, more precisely toward the bearing accommodating space 1114d2, so that the various bearings 143, 1441, and 1442 accommodated in the bearing accommodating space 1114d2 are more It can run quickly and be cooled at the same time.

Referring to FIGS. 4 and 6 , the second inflow passage part 1715 may include a second refrigerant inlet pipe 1716 and a second refrigerant inlet 1717 .

The second refrigerant inlet pipe 1716 has one end branched with the first refrigerant inlet pipe 1712 in the middle of the refrigerating cycle device, and the other end of the motor housing 111 constituting the second space 1114b of the motor room 1114. ) Can be inserted into and coupled to the second refrigerant inlet 1717 penetrating between the outer and inner circumferential surfaces of the

The second refrigerant inlet pipe 1716 may be formed smaller than or equal to the inner diameter of the refrigerant circulation pipe constituting the refrigeration cycle device. Accordingly, it is possible to suppress excessive injection of refrigerant circulating through the refrigerating cycle device into the motor housing 111 of the compressor.

The second refrigerant inlet 1717 may be formed to be positioned on substantially the same axial line as the first refrigerant inlet 1713 . Accordingly, the first refrigerant inlet 1713 and the second refrigerant inlet 1717 are positioned farthest from the refrigerant outlet 1721 to be described later, so that the refrigerant flows through the first space 1114a and the second space of the motor room 1114. (1114b) can stay for a long time, through which each bearing and rolling element can be effectively cooled.

Although not shown in the drawing, the inlet passage part 171 may be formed of one inlet passage part. In this case, as the axial bearings 1441 and 1442 are provided in the first space 1114a, the inflow passage part 171 is the first inlet passage part 171 of the motor room 1114 like the first inflow passage part 1711 described above. It may be desirable to be formed to communicate with the space 1114a.

Referring to FIGS. 4 and 6 , the outflow passage part 172 includes a refrigerant outlet 1721 and a refrigerant outlet pipe 1722 .

The refrigerant outlet 1721 is formed to penetrate between the inner and outer circumferences of the motor housing 111 in the second space 1114b of the motor chamber 1114. The refrigerant outlet 1721 may be formed at a position spaced apart from the second refrigerant inlet 1717 along the circumferential direction, for example, at a position with a phase difference of about 180° from the second refrigerant inlet 1717. Accordingly, the refrigerant outlet 1721 is located farthest from the second refrigerant inlet 1717 in the circumferential direction, so that the refrigerant flowing into the second space 1114b stays in the second space 1114b for a long time while controlling the transmission unit and the The two radial bearings 147 can be effectively cooled.

One end of the refrigerant outlet pipe 1722 is inserted into and coupled to the refrigerant outlet 1721, and the other end of the refrigerant outlet pipe 1722 passes through a refrigerant control valve 1733 to be described later to the suction side of the first compression unit 150 or It may be connected to the suction side of the second compression unit 160 .

Although not shown in the drawing, the other end of the refrigerant outlet pipe 1722 may be connected to the refrigerant circulation pipe of the refrigerating cycle device. For example, the other end of the refrigerant outflow pipe 1722 is between the outlet of the expander 30 and the inlet of the evaporator 40 (hereinafter, the first position) or between the outlet of the evaporator and the inlet of the compressor (the first inlet) (hereinafter, the second position). location) may be connected.

However, in these cases, as the refrigerant passing through the motor chamber 1114 is converted from liquid refrigerant to gas refrigerant, it may be preferable that the refrigerant outlet pipe 1722 is connected to the second position rather than the first position.

Referring to FIG. 4 , the connection passage part 173 according to the present embodiment includes a first connection pipe 1731, a second connection pipe 1732, a refrigerant control valve 1733, and a valve control unit 1734.

The first connection pipe 1731 is connected to the suction side of the outflow passage part 172 and the second compression part 160, and the second connection pipe 1732 is connected to the outflow passage part 172 and the first compression part 150. ) can be connected between the suction side of

Specifically, the first connection pipe 1731 may be connected between the refrigerant outlet pipe 1722 and the refrigerant connection pipe 116, and the second connection pipe 1732 may be connected between the middle of the refrigerant outlet pipe and the refrigerant suction pipe. Accordingly, the refrigerant discharged through the refrigerant outlet pipe 1722 moves to the suction side of the second compression unit 160 through the first connection pipe 1731 or through the second connection pipe 1732 to the first compression unit ( 150) can be moved to the suction side.

In other words, the refrigerant supplied to the motor room 1114 through the inlet passage 171 moves to the second compression unit 160 during high-load operation and is compressed in two stages, whereas during low-load operation, the first compression unit Moving to (150), the cooling capacity of the first compression unit 150 may be lowered.

The refrigerant control valve 1733 may be installed at a point where the refrigerant outlet pipe 1722, the first connection pipe 1731, and the second connection pipe 1732 meet each other. For example, the refrigerant control valve 1733 is composed of a solenoid-type 3-way valve, the first opening of the refrigerant control valve 1733 has the other end of the refrigerant outlet pipe, and the second opening has a first connection. One end of the tube 1731 and one end of the second connection tube 1732 may be connected to the third opening, respectively.

The opening and closing directions of the refrigerant control valve 1733 may be controlled by a valve control unit 1734 to be described later. For example, during high load operation, the refrigerant outlet pipe 1722 and the first connection pipe 1731 are opened while the refrigerant outlet pipe 1722 and the second connection pipe 1732 are controlled to be closed. In this case, the refrigerant outlet pipe 1722 and the second connection pipe 1732 may be opened while the refrigerant outlet pipe 1722 and the first connection pipe 1731 may be controlled to be closed.

Although not shown in the drawings, the refrigerant control valve 1733 may be independently installed in the middle of the refrigerant outlet pipe 1722, the middle of the first connection pipe 1731, and the middle of the second connection pipe 1732. In this case, the refrigerant control valve 1733 is composed of a 2-way valve, and the flow direction of the refrigerant according to the load is the same as in the above-described embodiment.

1 and 4, the valve control unit 1734 determines whether to discharge the refrigerant injected into the motor housing 111 in the middle of the refrigerating cycle device to the suction side of the second compression unit 160 or the first compression unit ( 150) to select whether to discharge to the suction side, and may include a measuring unit 1734a and a control unit 1734b.

The measuring unit 1734a may include a pressure sensor, a temperature sensor, and a flow rate sensor to measure the refrigerant state, for example, the pressure (P), temperature (T), and heat quantity (Q) of the refrigerant.

The control unit 1734b calculates the changed flow rate (ΔQ) of the refrigerant supplied to the motor room 1114 of the motor housing 111 through the inlet passage 171, and calculates the operating range according to the changed flow rate to meet the demand load. It determines whether the operation range is out of range, and if the required load is within the range of operation range, the refrigerant control valve 1733 is fixed. ) can be controlled.

The turbo compressor according to the present embodiment as described above operates as follows.

That is, when power is applied to the transmission unit 120, rotational force is generated by an induced current between the stator 121 and the rotor 122, and the rotational shaft 130 is moved along with the rotor 122 by this rotational force. will make a turn

Then, the rotational force of the transmission unit 120 is transmitted to the first impeller 151 and the second impeller 161 by the rotation shaft 130, and the first impeller 151 and the second impeller 161 are respectively impellers. The accommodation spaces 1122 and 1132 rotate simultaneously.

Then, the refrigerant passing through the evaporator 40 of the refrigeration cycle device is introduced into the first impeller accommodating space 1122 through the refrigerant suction pipe 115 and the first inlet 1121, and the refrigerant flows through the first impeller 151 While moving along the first blade 1512, the static pressure rises and at the same time passes through the first diffuser 1123 with centrifugal force.

Then, the kinetic energy of the refrigerant passing through the first diffuser 1123 leads to an increase in the pressure head by the centrifugal force in the first diffuser 1123, and the centrifugally compressed high-temperature and high-pressure refrigerant flows in the first volute 1124. It is collected and discharged from the first compression unit 150 through the first discharge port 1125.

Then, the refrigerant discharged from the first compression unit 150 is guided to the second inlet 1131 of the second impeller housing 113 constituting the second compression unit 160 through the refrigerant connection pipe 116, As the refrigerant moves along the second blade 1612 of the second impeller 161, the static pressure rises again, and at the same time, it passes through the second diffuser 1133 with centrifugal force.

Then, the refrigerant passing through the second diffuser 1133 is compressed to a desired pressure by centrifugal force, and the high-temperature and high-pressure refrigerant compressed in two stages is collected in the second volute 1134 and discharged through the second outlet 1135 and the refrigerant. A series of processes of being discharged to the condenser 20 through the pipe 117 are repeated.

At this time, the first impeller 151 and the second impeller 161 are each impeller 151 by the refrigerant sucked through the first inlet 1121 and the second inlet 1131 of each impeller housing 112, 113. ) (161) is subjected to thrust pushed toward the rear. However, in the case of a so-called double-ended turbo compressor in which the first impeller 151 and the second impeller 161 are arranged so as to be opposite to each other as in the present embodiment, the thrust generated by the first impeller 151 and the second impeller 161 The thrust generated in can be offset while forming the opposite direction to each other.

However, even in such a double-ended turbo compressor, during actual operation, the thrust generated from the first compression unit 150 and the thrust generated from the second compression unit 160 may not be the same or constant. Due to this, the rotating shaft 130 can be pushed in the axial direction toward the first compression unit 150 or the second compression unit 160, typically toward the first compression unit 150 or/and the second compression unit ( Axial bearings 1441 and 1442 may be installed on the 160 side.

In addition, radial bearings 143 and 147 are provided inside the housing 110 to support the rotating shaft 130 with respect to the housing 110 in a radial direction. The radial bearings 143 and 147 may be provided on both sides of the rotation shaft 130 in the axial direction, that is, on the first compression unit 150 side and the second compression unit 160 side, respectively.

As the axial bearings 1441 and 1442 and the radial bearings 143 and 147 as described above rotate at high speed (approximately 40,000 rpm or more), the high-temperature frictional heat between them and the rotary shaft 130 this will happen In addition, high-temperature motor heat is generated while the transmission unit 120 generates high-speed rotational force. Accordingly, the motor compartment 1114 of the motor housing 111 may be overheated due to frictional heat and motor heat, resulting in deterioration in performance of the compressor.

Therefore, in addition to the refrigerant described above, a separate cooling fluid is supplied to the motor housing 111 to cool the heat generated in the motor chamber 1114, or as described above, a portion of the refrigerant that has passed through the condenser 20 is transferred to the motor housing. Heat generated in the motor room 1114 can be cooled by supplying it to 111.

In this embodiment, one end of the first refrigerant inlet pipe 1712 and one end of the second refrigerant inlet pipe 1716 are connected in parallel to the outlet of the condenser 20, and the other end of the first refrigerant inlet pipe 1712 and the second The other end of the refrigerant inlet pipe 1716 is connected to the first refrigerant inlet 1713 and the second refrigerant inlet 1717 penetrating the motor housing 111 to form the motor room 1114 and the first space 1114a and It can communicate with each of the second spaces 1114b. Accordingly, the liquid refrigerant passing through the condenser 20 is injected into the first space 1114a and the second space 1114b, and the refrigerant is supplied to each of the first space 1114a and the second space 1114b. Heat exchange with the bearings [(143)(147)][(1441)(1442)] and the rolling element 120 causes evaporation to cool each of the bearings and the rolling element.

For example, part of the liquid refrigerant flowing into the first space 1114a, specifically, the bearing accommodating space 1114a2 through the first refrigerant inlet 1713 connects to the first side surface 1324a of the thrust runner 1324. It passes through the second air gap G2 formed between the facing second side surfaces 142b of the first bearing shell 142 . At this time, the refrigerant moves from the outer circumferential side of the first axial bearing 1441 to the inner circumferential side of the first axial bearing 1441 as well as the first bearing shell 142 facing the first axial bearing 1441. The second side surface 142b and the first side surface 1324a of the thrust runner 1324 are cooled.

In addition, part of the liquid refrigerant flowing into the first space 1114a, specifically, the bearing accommodating space 1114a2 through the first refrigerant inlet 1713 faces the second side surface 1324b of the thrust runner 1324. It passes through the third air gap G3 formed between the first side surfaces 1115a of the bearing support part 1115 . At this time, while moving from the outer circumferential side of the second axial bearing 1442 to the inner circumferential side, the first side surface 1115a of the bearing support 1115 facing the second axial bearing 1442 as well as the second axial bearing 1442 ) and the second side surface 1324b of the thrust runner 1324 are cooled.

In addition, a part of the refrigerant flowing into the second air gap G2 flows into the fourth air gap G4 provided between the first shaft hole 142c of the first bearing shell 142 and the rotating shaft, and the fourth air gap It acts as a working fluid for the first radial bearing 143 provided in (G4) and at the same time cools the first radial bearing 143 and the rotating shaft 130.

In addition, another part of the liquid refrigerant flowing into the bearing receiving space 1114a2 passes through the second axial bearing 1442 through the first air gap G1 formed between the inner circumferential surface of the motor housing 111 and the outer circumferential surface of the thrust runner 1324. While moving from the outer circumferential side of the second axial bearing 1442 to the inner circumferential side, the refrigerant moves toward the second axial bearing 1442 and the thrust runner 1324 facing the second axial bearing 1442. The second side surface 1324b and the first side surface 1115a of the bearing support 1115 are cooled.

This refrigerant moves to the motor accommodating space 1114a1 of the first space 1114a through the first through hole 1115c and the refrigerant through hole 1115d provided in the bearing support part 1115, and the refrigerant is transferred to the electric motor 120 ) passes through the gap (unsigned) in the axial direction and moves to the second space 1114b. At this time, the transmission unit 120 is in contact with the refrigerant passing through the air gap of the transmission unit 120 and the refrigerant flowing into the second space 1114b, so that the motor heat generated in the transmission unit 120 can be quickly cooled. there is.

Meanwhile, part of the refrigerant that has moved to the second space 1114b is part of the refrigerant supplied to the second space 1114b through the second refrigerant inlet pipe 1716 and the second refrigerant inlet 1717 together with the fifth air gap. (G5) flows into the second shaft hole 146c of the second bearing shell 146, and this refrigerant acts as a working fluid for the second radial bearing 147 and at the same time the second radial bearing 147 and the rotation shaft 130 are cooled.

The refrigerant introduced into the second space 1114b circulates through the second space 1114b and then is discharged to the outside of the motor housing 111 through the refrigerant outlet 1721 and the refrigerant outlet pipe 1722, and the refrigerant is refrigerant. The refrigerant may be supplied to the suction side of the second compression unit 160 or to the suction side of the first compression unit 150 through a conduit to which the refrigerant outlet pipe 1722 is connected through the control valve 1733 . At this time, the valve control unit 1734 may increase compression efficiency by performing a load response operation for controlling the opening and closing direction of the refrigerant control valve 1733 in real time.

Referring to FIGS. 1 and 8 , the measuring unit 1734a measures the pressure (P), temperature (T), and heat quantity (Q) of the refrigerant in real time (S10).

Then, the control unit 1734b calculates the changed flow rate ΔQ as the refrigerant is additionally supplied to the first compression unit 150 or the second compression unit 160 based on the value measured by the measurement unit 1734a (S11 ), calculates the operating range according to the changed flow rate to determine whether the required load has deviated from the operating range (S12), and fixes the opening and closing direction of the refrigerant control valve 1733 when the required load converges within the operating range (S13), on the other hand, if it is out of the required load, the opening and closing direction of the refrigerant control valve 1733 is switched to control the flow rate according to the required load (S14).

For example, during high load operation, the refrigerant control valve 1733 is opened toward the first connection pipe 1731 as shown in FIG. 7A to supply the refrigerant passing through the motor housing 111 to the second compression unit 160. . The refrigerant that has passed through the motor housing 111 has a lower refrigerant temperature than the refrigerant compressed in the first stage in the first compression unit 150 . Then, the temperature of the refrigerant flowing into the second compression unit 160 is lowered to increase the refrigerant intake amount, and at the same time, the required energy for driving the second compression unit 160 is reduced, thereby improving compression efficiency.

However, the flow rate of the refrigerant supplied to the second compression unit 160 may be appropriately adjusted according to circumstances. For example, in a surging state, the minimum flow rate at which the compressor can be driven is supplied, and in a choking state, the maximum possible flow rate may be supplied. This can be controlled by the control method in the valve control unit 1734 described above.

On the other hand, during low-load operation, the refrigerant control valve 1733 is opened toward the second connection pipe 1732, and the refrigerant passing through the motor housing 111 can be supplied toward the first compression unit 150, as shown in FIG. 7B. The temperature of the refrigerant passing through the motor housing 111 is higher than that of the refrigerant sucked into the first compression unit 150 . Then, as the temperature of the suction refrigerant rises and suction loss occurs, the cooling capacity of the compressor is appropriately reduced. Even in this case, the opening/closing direction or/and opening amount of the refrigerant control valve 1733 can be controlled through the control method in the valve controller 1734 described above.

On the other hand, in the turbo compressor as described above, the impellers 151 and 161 suck refrigerant while rotating at high speed inside the respective impeller accommodating parts (ie, outer shrouds) 1122 and 1132. Accordingly, between the outer circumferential surfaces of the impellers 151 and 161 and the inner circumferential surfaces of the impeller accommodating portions 1122 and 1132 facing them, the impellers 151 and 161 can rotate with respect to the impeller housings 112 and 113. The gap (rotation gap) must be secured. The rotation interval may be determined by the radial bearings 143 and 147 and the axial bearings 1441 and 1442 described above, and is approximately several tens of μm or more.

However, the rotation interval may act as a leakage passage through which the refrigerant may leak. In particular, the suction side of the impellers 151 and 161, that is, the part where the suction port 1121 and 1131 and the impeller accommodating part 1122 and 1132 are connected forms the beginning of the rotation interval, so refrigerant leakage is prevented at this part. It is advantageous to reduce the suction loss of the refrigerant.

Accordingly, in the present embodiment, the suction-side sealing portion is provided at the portion where the suction port and the impeller accommodating portion are connected, so that leakage of refrigerant into the rotational interval can be suppressed. Through this, the suction loss can be minimized and the compressor performance can be improved.

The suction-side sealing part may be formed of only one of the outer sealing part and the inner sealing part, or may be formed of a combination of the outer sealing part and the inner sealing part. Hereinafter, the suction-side sealing portion composed of the combination of the outer sealing portion and the inner sealing portion will be described first.

9 is a perspective view of the first impeller housing according to the present embodiment in which it is separated, and FIG. 10 is a front view of the assembled first impeller housing of FIG. 9, and FIG. 2 This is a cross-sectional view of the suction-side sealing part enlarged.

Referring to FIGS. 9 to 11 , the first suction-side sealing part 155 according to the present embodiment may include a first outer sealing part 1551 and a first inner sealing part 1552 . For example, the first outer sealing portion 1551 may be formed on an inner circumferential surface of the first impeller accommodating portion 1122 , and the first inner sealing portion 1552 may be formed on an outer circumferential surface of the first impeller 151 . The first suction-side sealing portion 155 including the first outer sealing portion 1551 and the first inner sealing portion 1552 forms a first axial sealing portion.

Specifically, the first outer sealing portion 1551 may include a first outer annular protrusion 1551a and a first outer annular groove 1551b formed on the inner circumferential surface of the first impeller accommodating portion 1122 . The first outer annular projection 1551a may correspond to a first inner annular groove 1552b to be described later, and the first outer annular groove 1551b may be formed to correspond to a first inner annular projection 1552a to be described later. In other words, the first outer annular projection 1551a is inserted into the first inner annular groove 1552b to be described later, and the first inner annular projection 1552a to be described later is inserted into the first outer annular groove 1551b, respectively, to form a kind of labyrinth seal. (labyrinth seal) can be formed.

The first outer sealing portion 1551 may be formed one by one or in plurality along the axial direction. In other words, the first outer annular projection 1551a and the first outer annular groove 1551b may be formed one by one along the axial direction or alternately formed one by one along the axial direction. The number of first outer annular projections 1551a and the number of first outer annular grooves 1551b constituting the first outer sealing portion 1551 may be directly related to the sealing force of the first suction side sealing portion 155 . Accordingly, it may be advantageous in terms of sealing that the first outer annular groove 1551b of the first outer annular projection 1551a is formed as many times as possible. In this embodiment, the first outer annular projection 1551a and the first outer annular groove 1551b are formed in three rows in an axial direction.

The first outer annular projection 1551a may be formed to have the same height and cross-sectional area along the circumferential direction. Accordingly, the first inner annular groove 1552b into which the first outer annular projection 1551a is inserted may have the same depth and cross-sectional area along the circumferential direction as the first outer annular projection 1551a. Through this, the distance between the first outer annular projection 1551a and the first inner annular groove 1552b may be maintained constant in the circumferential direction.

The first outer annular projection 1551a and the first inner annular groove 1552b may be formed in various shapes such as a rectangular cross section or a wedge cross section. However, when the first outer annular projection 1551a and the first inner annular groove 1552b are formed in a rectangular cross-section, the sealing passage between the first outer annular projection 1551a and the first inner annular groove 1552b becomes longer, thereby preventing sealing. effect can be improved.

In addition, each of the first outer annular projections 1551a arranged along the axial direction may have the same height and cross-sectional area. Accordingly, each of the first inner annular grooves 1552b into which each of the first outer annular projections 1551a are inserted may have the same depth and cross-sectional area along the axial direction. Through this, the distance between each first outer annular projection 1551a and each first inner annular groove 1552b can maintain a constant length in the axial direction and radial direction.

However, in some cases, each of the first outer annular projection 1551a and the first inner annular groove 1552b arranged along the axial direction may have different heights and cross-sectional areas. For example, in the case of the first outer annular projection 1551a and the first inner annular groove 1552b arranged along the axial direction, the height of the first outer annular projection 1551a gradually increases toward the first inlet 1121. The depth of the first inner annular groove 1552b may be gradually widened. Accordingly, the sealing force of the first suction-side sealing part 155 is greatest at the upstream side in the direction in which the refrigerant flows backward, so that leakage of the refrigerant can be more effectively reduced.

The first inner sealing portion 1552 may be formed to correspond to the first outer sealing portion 1551 described above. In other words, the first inner sealing portion 1552 may include a first inner annular groove 1552b and a first inner annular protrusion 1552a formed on the outer circumferential surface of the first impeller 151 .

The first inner annular groove 1552b and the first inner annular projection 1552a may be formed to correspond to the first outer annular projection 1551a and the first outer annular groove 1551b described above, respectively. In other words, the first inner annular groove 1552b and the first inner annular projection may have the same shape as the first outer annular projection 1551a and the first outer annular groove 1551b except for a different order. . Accordingly, the first inner annular groove 1552b is replaced with the description of the first outer annular groove 1551b, and the first inner annular projection 1552a is replaced with the description of the first outer annular projection 1551a.

As described above, when the first suction-side sealing portion 155 is composed of a combination of the first outer sealing portion 1551 and the first inner sealing portion 1552, the first outer annular shape of the first outer sealing portion 1551 The protrusion 1551a is formed in the first inner annular groove 1552b of the first inner sealing portion 1552 and in the first outer annular groove 1551b of the first outer sealing portion 1551. The first inner sealing portion 1552 Each of the first inner annular projections 1552a may be inserted and engaged by a preset depth. Accordingly, the first suction-side sealing part 155 has a zigzag shape with a narrow and long sealing passage, so that the refrigerant compressed in the first stage while passing through the first impeller 151 passes through the inner circumferential surface of the first impeller accommodating part 1122. It is possible to effectively suppress leakage while flowing backward through between the outer circumferential surfaces of the first impeller 151 . Through this, the performance of the compressor can be improved by reducing the suction loss in the first compression unit.

However, when the first outer sealing portion 1551 and the first inner sealing portion 1552 are formed unevenly and interlocked with each other, the first outer annular projection 1551a constituting the first outer sealing portion 1551 and the second outer ring-shaped projection 1551a The first inner annular projections 1552a constituting the first inner sealing portion 1552 may overlap each other in the axial direction. Then, when assembling by pushing the first impeller housing 112 to the motor housing 111 in the axial direction, the protruding side of one sealing part is caught on the protruding side of the other sealing part (inner surface of the groove), and thereby the first impeller housing ( 112) cannot be assembled to the motor housing 111.

Therefore, as in the present embodiment, when the first outer sealing portion 1551 and the first inner sealing portion 1552 constituting the first suction side sealing portion 155 are engaged with each other to form a labyrinth seal, the first impeller The housing 112 may be assembled by separating the left and right housing blocks. For example, the first impeller housing 112 is formed by assembling the housing blocks on both sides independent of each other, and the first impeller housing 112 can be bolted to the first flange portion 1111 of the motor housing 111. .

9 and 10, the first impeller housing 112 may include a first left housing block 112' and a first right housing block 112". The first left housing block and the first The right housing blocks are formed to be symmetrical to each other, so that both sides of the first impeller 151 can be butted and fastened.

For example, the first left housing block 112' is formed in an approximate semicircular shape with its right side forming a flat surface when projected in an axial direction, and the first right housing block 112" is formed in a substantially semicircular shape with the first left housing block 112'. may be formed in an opposite shape, that is, an approximately semicircular shape in which the left side is a plane when projected in an axial direction.

At the center of the right side of the first left housing block 112', there is a first left inlet 1121', a first left impeller accommodating part 1122', a first left diffuser 1123', and a first left volute 1124'. ) are formed successively, and in the center of the left side of the first right housing block 112", the first right inlet 1121", the first right impeller accommodating part 1122", the first right diffuser 1123", One right volute 1124" may be formed in succession.

The first left inlet 1121' is combined with the first right inlet 1121" to form the first inlet 1121, and the first left impeller accommodating portion 1122' is combined with the first right impeller accommodating portion 1122". Combined to form the first impeller accommodating part 1122, the first left diffuser 1123' is combined with the first right diffuser 1123" to form the first diffuser 1123, the first left volute 1124' In combination with the first right volute 1124 ", the first volute 1124 may be formed.

As described above, the first left housing block 112' and the first right housing block 112" constituting the first impeller housing 112 are provided with fastening protrusions 1126' and 1126", respectively, so that the first impeller ( As both sides of 151) are butted and fastened, the first outer sealing portion 1551 of the first impeller housing 112 and the first inner sealing portion 1552 of the first impeller 151 are formed in multiple stages to each other. can be combined interlockingly. Accordingly, the gap between the inner circumferential surface of the first impeller housing 112 and the outer circumferential surface of the first impeller 151 becomes longer while forming a zigzag shape as described above, so that the sealing effect in this gap can be enhanced. Through this, the refrigerant compressed in the first stage in the first impeller 151 through the first inlet 1121 is suppressed from leaking between the inner circumferential surface of the first impeller housing 112 and the outer circumferential surface of the first impeller 151, thereby improving compressor performance. can be raised

Although not shown in the drawings, only the part corresponding to the first outer sealing part 1551 is formed in the first impeller housing 112, that is, the part corresponding to the first impeller accommodating part 1122. 112") may be separately formed and assembled. In this case, the first inlet 1121, the first diffuser 1123, and the first volute 1124 may be formed in a circular shape on one housing block.

Meanwhile, the second suction-side sealing part 165 may include a second outer sealing part 1651 and a second inner sealing part 1652 . For example, the second outer sealing portion 1651 may be formed on an inner circumferential surface of the second impeller accommodating portion 1132 , and the second inner sealing portion 1652 may be formed on an outer circumferential surface of the second impeller 161 . The second suction-side sealing portion 165 including the second outer sealing portion 1651 and the second inner sealing portion 1652 forms a second axial sealing portion.

The second outer sealing portion 1651 may correspond to the first outer sealing portion 1551 , and the second inner sealing portion 1652 may correspond to the first inner sealing portion 1552 . For example, the second outer sealing portion 1651 includes the second outer annular projection 1651a and the second outer annular groove 1651b, and the second inner sealing portion 1652 includes the second inner annular projection 1652a and the second outer annular groove 1651b. 2 may be formed of an inner annular groove (1652b).

The second outer annular projection 1651a may correspond to the first outer annular projection 1551a, and the second outer annular groove 1651b may correspond to the first outer annular groove 1551b. The second inner annular projection 1652a may correspond to the first inner annular projection 1552a, and the second inner annular groove 1652b may correspond to the first inner annular groove 1552b. Accordingly, the second suction-side sealing part 165 is replaced with the description of the first suction-side sealing part 155 .

In addition, the second impeller housing 113 according to this embodiment may correspond to the first impeller housing 112 described above. For example, the second impeller housing 113 is composed of a second left housing block 113' and a second right housing block 113", and the second left housing block 113' and the second right housing block ( 113 ") are formed symmetrically with each other and can be fastened by facing each other on both sides of the second impeller 161.

The second left housing block 113' may correspond to the first left housing block 112', and the second right housing block 113" may correspond to the first right housing block 112". Accordingly, the second impeller housing 113 is replaced with the description of the first impeller housing 112.

As described above, as the second left housing block 113′ and the second right housing block 113″ constituting the second impeller housing are butted and fastened on both sides of the second impeller 151, the second impeller housing 113 ) The second outer sealing portion 1651 of the second impeller 161 and the second inner sealing portion 1652 of the second impeller 161 may be formed in multiple stages, respectively, and combined to engage with each other.

Accordingly, the gap between the inner circumferential surface of the second impeller housing 113 and the outer circumferential surface of the first impeller 161 becomes longer while forming a zigzag shape, so that the sealing effect in this gap can be enhanced. Through this, it is possible to suppress leakage of the refrigerant compressed in two stages in the second impeller 161 by flowing backward from the discharge side to the suction side through the air gap between the inner circumferential surface of the second impeller housing 113 and the outer circumferential surface of the second impeller 161. Yes. (See Fig. 11)

However, it may not be easy to complicate and lengthen the sealing passage constituting each of the sealing parts [(155)(156)][(165)(166)] in the turbocompressor of this embodiment, especially in the small turbocompressor. Accordingly, minimizing the gap in the simple and short sealing passage is advantageous in suppressing refrigerant leakage through the sealing passage. However, if the gap between the sealing passages is formed too small, reliability may be deteriorated because projections constituting the sealing passages or projections and grooves collide with each other during radial and axial movement of the rotating shaft. Accordingly, it may be preferable that the gap between the sealing passage of the first discharge-side sealing part is smaller than the amount of movement of the rotating shaft while securing the sealing force.

Referring to FIG. 11, the axial clearance t11 of the first suction-side sealing part 155 is the axial clearance t31 of the first axial bearing 1441 or the axial clearance of the second axial bearing 1442. It is formed larger than or equal to the gap t32, and the radial gap t12 of the first suction side sealing part 155 is the radial gap t41, t42 of the first and second radial bearings 143 and 147. ) can be formed greater than or equal to.

Here, the axial gap t11 of the first suction-side sealing part 155 is the axial gap between the projections of the sealing part facing each other, and the radial gap t12 of the first suction-side sealing part 155 is It can be defined as the radial spacing between projections and grooves facing each other.

In addition, the axial clearance t31, t32 or the radial clearance t41 (unsigned) of each bearing [(1441)(1442)][(143)(147)] faces the rotating shaft 130. As the distance between the main surfaces of the bearing, when a gas foil bearing is applied as in this embodiment, it can be defined as a bearing gap in a maximum pressed state in which the bump foil of each bearing is maximally pressed.

The axial gap t11 and the radial gap t12 of the first suction-side sealing part as described above are the amount of pressure of the bump foil, the deformation amount of the first suction-side sealing part by centrifugal force, and the deformation amount of the first suction-side sealing part by thermal expansion. etc. can be formed in consideration. However, the radial gap t12 of the first suction-side sealing part may be formed by additionally considering the amount of tilt due to the inclination of the rotation shaft and the amount of deformation due to pressure.

This may be equally applied to the first discharge-side sealing portion 156 , the second suction-side sealing portion 165 , and the second discharge-side sealing portion 166 in addition to the first suction-side sealing portion 155 . However, when the second discharge-side sealing portion 166 is unevenly formed on only one sealing portion as in the present embodiment, the second discharge-side sealing portion 166 may be formed considering only the gap between the radial bearings 143 and 147. can

On the other hand, the case where there is another embodiment for the suction-side sealing part is as follows.

That is, in the above-described embodiment, the outer sealing part and the inner sealing part are each formed unevenly, and the protrusions are inserted into the grooves facing them, respectively, but in some cases, only one of the outer sealing part and the inner sealing part may be formed unevenly. may be

12 is a perspective view showing a first impeller housing having a first suction-side sealing unit according to another embodiment after being broken, and FIG. 13 is an enlarged cross-sectional view of the first suction-side sealing unit in FIG. 12 .

Referring to FIGS. 12 and 13 , the first suction-side sealing part 155 according to the present embodiment may include a first outer sealing part 1551 and a first inner sealing part 1552 . Either one of the first outer sealing portion 1551 and the first inner sealing portion 1552 may be formed unevenly. In this embodiment, an example in which the first inner sealing portion 1552 is unevenly formed will be described.

The first inner sealing portion 1552 may include a first inner annular protrusion 1552a and a first inner annular groove 1552b. The first inner annular projection 1552a and the first inner annular groove 1552b may be formed in the same manner as in the embodiment of FIG. 11 described above. Therefore, the description of the first inner annular projection 1552a and the first inner annular groove 1552b is replaced with the description of the first inner annular projection 1552a and the first inner annular groove 1552b in the embodiment of FIG. 11 . .

The first outer sealing portion 1551 may include a first sealing portion receiving groove 1551c.

The first sealing unit accommodating groove 1551c may be made of a single groove to accommodate one or a plurality of first inner annular projections 1552a. For example, the first inner annular projections 1552a of each row arranged in the axial direction may have the same height in the radial direction. Accordingly, the first sealing unit receiving groove 1551c is formed to be recessed in the radial direction on the inner circumferential surface of the first impeller housing unit 1122, and the first sealing unit receiving groove 1551c is recessed to the same depth along the axial direction. can be formed

Specifically, the first sealing unit receiving groove 1551c is formed in an annular shape, and one end in the axial direction, that is, the downstream end facing the first diffuser 1123 in the axial direction is opened in a smooth tube shape, and the other end in the axial direction, That is, the end of the current side facing the first inlet 1121 in the axial direction may be formed stepwise. In other words, the inner diameter of the downstream end of the first sealing part receiving groove 1551c is larger than the outer diameter of the first inner annular projection 1552a, and the inner diameter of the current end of the first sealing part receiving groove 1551c is the first inner diameter. It may be formed smaller than the outer diameter of the annular protrusion 1552a.

As described above, when the first inner sealing portion 1552 is formed unevenly, while the first outer sealing portion 1551 is formed as a groove with one end open, the first impeller when assembling the first impeller housing 112 The housing 112 may be assembled by pushing in the axial direction without assembling the first impeller 151 on both sides. Through this, the first impeller housing 112 can be manufactured and assembled as a single component without being separated into left and right housing blocks, so that manufacturing and assembly of the first impeller housing 112 can be facilitated.

Although not shown in the drawing, the second suction-side sealing part 165 may be formed in the same way as the first suction-side sealing part 155 . Accordingly, the second impeller housing 113 may be formed as a single component like the first impeller housing 112 and inserted into the second impeller 161 by pushing it in the axial direction.

On the other hand, the case where there is another embodiment for the suction-side sealing part is as follows.

That is, in the above-described embodiment, the outer sealing portion and the inner sealing portion have the same protrusion height, but in some cases, the outer sealing portion and/or the inner sealing portion may have different protrusion heights and groove depths.

14 is a perspective view showing a first impeller housing having a first suction-side sealing unit according to another embodiment after being broken, and FIG. 15 is an enlarged cross-sectional view of the first suction-side sealing unit in FIG. 14 .

Referring to FIGS. 14 and 15 , the first suction-side sealing part 155 according to the present embodiment may include a first outer sealing part 1551 and a first inner sealing part 1552 . The first outer sealing portion 1551 and the first inner sealing portion 1552 may be formed unevenly with corresponding protrusions and grooves, and only one sealing portion is uneven with protrusions and grooves, and the other sealing portion has the opposite sealing portion. The first sealing unit receiving groove 1551c may be formed to be recessed so as to be accommodated. In this embodiment, an example in which the first inner sealing portion 1552 is unevenly formed will be described.

The first inner sealing portion 1552 may include a first inner annular protrusion 1552a and a first inner annular groove 1552b. The first inner annular projection 1552a and the first inner annular groove 1552b may be formed similarly to the embodiment of FIG. 11 described above. However, in this embodiment, the first inner annular projection 1552a may be differently formed along the axial direction.

Specifically, among the first inner annular projections 1552a, the height of the other first inner annular projection 1552a located on the downstream side of the height of the first inner annular projection 1552a adjacent to the first suction port 1121 on the current side can be formed high. Accordingly, among the first inner annular grooves 1552b, the other first inner annular grooves 1552b located on the downstream side may be formed deeper than the depth of the first inner annular grooves 1552b located on the current side.

The first outer sealing portion 1551 may include a first sealing portion receiving groove 1551c.

The first sealing unit accommodating groove 1551c may be made of a single groove to accommodate one or a plurality of first inner annular projections 1552a. However, the first sealing unit accommodating groove 1551c according to this embodiment is formed to be recessed in the radial direction on the inner circumferential surface of the first impeller accommodating unit 1122, but the first sealing unit accommodating groove 1551c is stepped along the axial direction. It can be formed in multiple stages.

Specifically, the first sealing unit receiving groove 1551c is formed in an annular shape, and one end in the axial direction, that is, the downstream end facing the first diffuser 1123 in the axial direction is opened in a smooth tube shape, and the other end in the axial direction, That is, the end of the current side facing the first inlet 1121 in the axial direction may be formed stepwise.

In addition, the gap between the current side end and the downstream end of the first sealing unit receiving groove 1551c is formed stepwise in multiple stages, and the inner diameter of the first sealing unit receiving groove 1551c is formed in a direction from the current side end to the downstream end. can be formed to increase In other words, of the first sealing unit receiving groove 1551c, the portion corresponding to the first inner annular projection 1552a on the current side is relatively shallow, and the portion corresponding to the first inner annular projection 1552a on the downstream side is formed relatively deep. It can be.

As described above, if the height of the first inner annular projection 1552a on the downstream side is formed higher than the height of the first inner annular projection 1552a on the current side, the depth of the first inner annular groove 1552b on the current side is greater than the depth of the first inner annular groove 1552b on the downstream side. The depth of the inner annular groove 1552b may be formed deeper. Then, not only the volume of the first inner annular groove 1552b constituting the labyrinth chamber increases, but also the sealing distance increases, so that the sealing effect for the refrigerant passing through the first suction-side sealing part 155 can be enhanced.

In addition, since the height of the first inner annular projection 1552a on the downstream side is formed higher than the height of the first inner annular projection 1552a on the current side, when the first impeller housing 112 is assembled, the first impeller housing 112 ) can be assembled by pushing in the axial direction without assembling on both sides of the first impeller 151. Through this, the first impeller housing 112 can be manufactured and assembled as a single component without being separated into left and right housing blocks, so that manufacturing and assembly of the first impeller housing 112 can be facilitated.

Although not shown in the drawing, the second suction-side sealing part 165 may be formed in the same way as the first suction-side sealing part 155 . Accordingly, the second impeller housing 113 may be formed as a single component like the first impeller housing 112 and inserted into the second impeller 161 by pushing it in the axial direction.

Meanwhile, in the above-described embodiments, an example in which both the first suction-side sealing unit 155 and the second suction-side sealing unit 165 are provided has been reviewed, but in some cases, the first suction-side sealing unit 155 And only one of the second suction side sealing portion 165 may be formed.

For example, the suction-side sealing unit described above may be formed only in the first compression unit 150 without forming the suction-side sealing unit in the second compression unit 160 . In other words, since the refrigerant sucked into the second compression unit 160 is positioned between the first compression unit 150 and the second compression unit 160, a portion of the refrigerant is transferred between the second impeller accommodating unit 1132 and the second compression unit 1132. Even if it leaks between the impellers 161, it is substantially located inside the compressor. On the other hand, the refrigerant sucked into the first compression unit 150 has not yet been sucked into the compressor 10, so some of the refrigerant not sucked into the first compression unit 150 is transferred to the evaporator depending on the condition of the refrigerating cycle device. It may flow back toward (40). Therefore, when only one of the first suction-side sealing part 155 and the second suction-side sealing part 165 is formed, the second suction-side sealing part 165 is excluded and only the first suction-side sealing part 155 is formed. can be formed

Accordingly, the manufacturing cost of the suction-side sealing unit can be reduced by reducing the number of suction-side sealing units. In addition, it is possible to secure performance of the compressor by optimizing the installation position of the suction-side sealing unit while reducing the number of suction-side sealing units.

10: compressor 20: condenser
30: expander 40: evaporator
110: housing 111: motor housing
1111: first flange portion 1111a: bearing shell seating groove
1111b: bearing shell seating surface 1112: second flange portion
1113: depression 1114: motor room
1114a: first space 1114b1: motor accommodating space
1114b2: bearing receiving space 1114b: second space
1115: bearing support 1115a: first side
1115b: second side surface 1115c: first through hole
1115d: refrigerant through hole 112: first impeller housing
112': first left housing block 112": second right housing block
112a: bearing shell receiving groove 112b: first housing fastening surface
1121: first inlet 1121': first left inlet
1121 ": first right inlet 1122: first impeller accommodating part
1122': first left impeller accommodating part 1122": first right impeller accommodating part
1123: first diffuser 1123': first left diffuser
1123 ": first right diffuser 1124: first volute
1124': first left volute 1124": first right volute
1125: first discharge port 1126', 1126": fastening protrusion
113: second impeller housing 113': second left housing block
113 ": second right housing block 1131: second inlet
1132: second impeller accommodating part 1133: second diffuser
1134: second volute 1135: second outlet
115: refrigerant suction pipe 116: refrigerant connection pipe
117: refrigerant discharge pipe 120: transmission part
121 stator 1211 stator core
1212: stator coil 122: rotor
130: rotation shaft 131: drive shaft
1311: magnet receiving part 1311a: magnet fixing jaw
132: first impeller shaft portion 1321: first shaft fixing portion
1322: first impeller fixing part 1323: first bearing surface part
1324: thrust runner 1324a: first side
1324b: second side surface 133: second impeller shaft portion
1331: second shaft fixing part 1332: second impeller fixing part
1333: second bearing surface portion 140: bearing portion
141: first bearing part 142: first bearing shell
142a: first side 142b: second side
142c: first soccer hole 1421: inner wall portion
1422: first side wall portion 1423: second side wall portion
1424: refrigerant receiving part 143: first radial bearing
1441: first axial bearing 1442: second axial bearing
145: second bearing part 146: second bearing shell
146a: first side 146b: second side
146c: second shaft hole 147: second radial bearing
150: first compression unit 151: first impeller
1511: first hub 1512: first blade
1513: first shroud 1513a: first inlet
1513b: first outlet part 155: first suction side sealing part
1551: first outer sealing portion 1551a: first outer annular projection
1551b: first outer annular groove 1551c: first sealing unit receiving groove
1552: first inner sealing part 1552a: first inner annular projection
1552b: first inner annular groove 156: first discharge-side sealing part
1561: front side sealing part 1562: rear side sealing part
160: second compression unit 161: second impeller
1611: second hub 1612: second blade
1613: second shroud 165: second suction side sealing part
1651: second outer sealing portion 1651a: second outer annular projection
1651b: second outer annular groove 1652: second inner sealing portion
1652a: second inner annular projection 1652b: second inner annular groove
166: second discharge side sealing part 170: refrigerant passage part
171: inflow passage part 1711: first inflow passage part
1712: first refrigerant inlet pipe 1713: first refrigerant inlet
1714: refrigerant inflow passage 1714a: first inflow passage
1714b: second inflow passage 1715: second inflow passage part
1716: second refrigerant inlet pipe 1717: second refrigerant inlet
1718: third inflow passage 172: outflow passage part
1721: refrigerant outlet 1722: refrigerant outlet pipe
173: connection passage part 1731: first connector
1732: second connection pipe 1733: refrigerant control valve
1734: valve control unit 1734a: measuring unit
1734b: control unit 1751: first refrigerant passage
1752: second refrigerant passage 1753: third refrigerant passage
1754: fourth refrigerant passage 181: first sealing member
182: second sealing member 183: third sealing member
G1, G2, G3, G4, G5: first, second, third, fourth, fifth pores
t11: Axial clearance of the first suction-side sealing part
t12: Radial gap of the first suction side sealing part
t31, t32: Axial clearance of the first and second axial bearings
t41: radial clearance of the first radial bearing

Claims (15)

housing; and
Including at least one impeller rotatably provided in the housing,
the housing,
intake;
a discharge port communicating with the suction port;
an impeller accommodating portion provided between the inlet and the outlet and into which the impeller is rotatably inserted; and
A turbo compressor comprising a suction-side sealing portion provided on at least one of an inner circumferential surface of the impeller accommodating portion and an outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating portion. According to claim 1,
The suction-side sealing portion is formed in at least one line along the axial direction,
The suction side sealing part,
A turbocompressor formed to be uneven in a radial direction on at least one of the inner circumferential surface of the impeller accommodating part and the outer circumferential surface of the impeller facing the inner circumferential surface of the impeller accommodating part. According to claim 1,
The suction side sealing part,
an inner sealing portion formed on an outer circumferential surface of the impeller; and
Including an outer sealing portion formed on the inner circumferential surface of the impeller accommodating portion facing the outer circumferential surface of the impeller,
The inner sealing part and the outer sealing part are formed unevenly so as to be engaged with each other. According to claim 3,
The outer sealing portion is alternately formed with protrusions and grooves along the axial direction,
The inner sealing part has grooves corresponding to the protrusions of the outer sealing part and protrusions corresponding to the grooves of the outer sealing part alternately formed along the axial direction,
A turbocompressor wherein at least a portion of the projections of the outer sealing part and the projections of the inner sealing part overlap in an axial direction. According to claim 3,
A driving motor is provided in the housing,
The impeller is coupled to an end of a rotating shaft coupled to a rotor of the driving motor,
A bearing supporting the rotation shaft is provided between the rotation shaft and the housing,
The distance between the inner sealing part and the outer sealing part,
A turbo compressor formed to be greater than or equal to a gap between the bearing and the rotating shaft. According to claim 1,
the housing,
motor housing; and
It includes an impeller housing provided with the impeller accommodating portion and coupled in an axial direction from an end side of the motor housing,
The impeller housing,
A turbo compressor consisting of a plurality of housing blocks assembled in a radial direction. According to claim 6,
The plurality of housing blocks,
A portion of the impeller accommodating portion is provided, respectively,
A part of the outer sealing part is provided in each of the impeller accommodating parts,
A turbocompressor having an inner sealing portion engaged with the outer sealing portion to form the suction side sealing portion on an outer circumferential surface of the impeller. According to claim 7,
The inner sealing portion has a plurality of annular projections and annular grooves alternately formed along the axial direction,
The outer sealing part has a plurality of annular grooves and annular projections alternately formed along the axial direction,
The annular projections of the inner sealing part are radially inserted into the annular groove of the outer sealing part at predetermined intervals, and the annular projections of the outer sealing part are radially inserted into the annular groove of the inner sealing part at predetermined intervals. compressor. According to claim 8,
The annular projection of the inner sealing part and the annular projection of the outer sealing part are each formed in plurality along the axial direction,
The plurality of annular projections,
Turbo compressors each having the same radial height. According to claim 1,
the housing,
motor housing; and
It includes an impeller housing provided with the impeller accommodating portion and coupled in an axial direction from an end side of the motor housing,
The impeller housing,
A turbo compressor in which the impeller accommodating portion extends from the inlet in the center and penetrates in the axial direction. According to claim 10,
On the outer circumferential surface of the impeller, annular projections and annular grooves constituting the suction-side sealing portion are alternately formed along the axial direction,
A turbocompressor wherein a sealing part receiving groove is formed stepwise on an inner circumferential surface of the impeller receiving part so that the suction side sealing part is inserted. According to claim 11,
A plurality of the annular projections are formed along the axial direction,
The annular projection is formed with a radial height increasing toward the discharge port from the inlet side,
The sealing part receiving groove,
A turbocompressor formed in multiple stages with an inner diameter increasing from the inlet side toward the discharge port. According to claim 1,
A plurality of the impellers are provided, and the plurality of impellers are rotatably accommodated in a plurality of different impeller accommodating units, respectively,
Among the plurality of impellers, the discharge side of the first impeller located on the current side communicates with the suction side of the second impeller located on the downstream side,
The turbocompressor wherein the suction-side sealing portion is provided between the outer circumferential surface of the plurality of impellers and the inner circumferential surface of the plurality of impeller accommodating portions respectively accommodating the plurality of impellers. According to claim 1,
A plurality of the impellers are provided, and the plurality of impellers are rotatably accommodated in a plurality of different impeller accommodating units, respectively,
Among the plurality of impellers, the discharge side of the first impeller located on the current side communicates with the suction side of the second impeller located on the downstream side,
The suction-side sealing portion is provided between the outer circumferential surface of the first impeller and the inner circumferential surface of the first impeller accommodating portion accommodating the first impeller. According to any one of claims 1 to 14,
The impeller is provided with a shroud coupled to surround the outer surface of the blade,
The shroud,
an inlet portion adjacent to the inlet; and
An outlet portion extending from the inlet portion and adjacent to the discharge port,
The suction side sealing part,
A turbo compressor provided between the outer circumferential surface of the inlet and the inner circumferential surface of the impeller accommodating part facing the same.

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