CN111371211A - Motor rotor for improving critical rotating speed, compressor and air conditioning equipment - Google Patents

Abstract

The invention relates to a motor rotor, a compressor and an air conditioner that can increase a critical rotational speed. The motor rotor comprises: a magnetic part (1), which is used to rotate under the action of an energized coil; and a shaft body (2), which is connected with the magnetic part. (1) Connect and extend away from the magnetic part (1) along the axial direction of the motor rotor, and the shaft body (2) is provided with a cavity (3) extending along the axial direction thereof. By applying the technical solution of the present application, the shaft body of the motor rotor is provided with a cavity, which improves the problem of the low critical speed of the motor rotor caused by the heavy weight in the prior art.

Description

Motor rotors, compressors and air conditioning equipment that increase critical speed

technical field

The invention relates to the field of refrigeration equipment, in particular to a motor rotor, a compressor and an air conditioner.

Background technique

Centrifugal refrigeration compressors are high-speed compressors. The rotor of the compressor rotates at high speed during operation and requires reliable bearings to support the rotor. The bearings used in conventional rotors mainly include rolling bearings, oil film bearings, and magnetic suspension bearings. For rolling bearings and oil film bearings, the compressor requires an additional oil lubrication system and a complex oil supply oil circuit system. At the same time, the refrigerant and lubricating oil are compatible, and a separation system needs to be added in the system, which will lead to the overall system being too complicated and huge.

Due to the high bearing capacity of rolling bearings and oil film bearings, the motor rotors used in conventional centrifugal compressors are all integrated structures. The weight of the compressor rotors of this structure is relatively heavy, which is not conducive to the improvement of the critical speed of the rotors. When the one-piece structure is used to make a larger rotor, the processing process is relatively complicated, and the equipment requirements are relatively high, which will increase the cost.

Therefore, in order to solve the complex oil circuit system of the compressor, an oil-free and environmentally friendly magnetic suspension bearing has appeared. For the magnetic suspension bearing, the oil supply system and separation system are omitted, but a more complex control system is added. Since the magnetic suspension bearing requires a stable power supply, in order to prevent the system from being suddenly cut off, a protection system needs to be added, which leads to the maintenance cost of the entire compressor. increase, the structure becomes more complex.

In order to solve the problem of the critical rotational speed of the compressor rotor, the existing compressors mainly increase the critical rotational speed of the rotor by reducing the length of the rotor or increasing the stiffness of the bearing. However, reducing the length of the rotor is affected by the size of each component, and the degree of optimization that can be done is relatively small. To improve the bearing stiffness, it is necessary to increase the volume of the bearing at high speed, which will lead to the overall increase of the compressor, which goes against the development trend of miniaturization.

SUMMARY OF THE INVENTION

The present invention aims to provide a motor rotor, a compressor and an air conditioner, so as to improve the problem of the low critical rotational speed of the motor rotor in the prior art due to its heavy weight.

According to an aspect of the embodiments of the present invention, the present invention provides a motor rotor of a compressor, the motor rotor comprising:

a magnetic portion for rotating under the action of an energized coil; and

The shaft body is connected with the magnetic part and extends away from the magnetic part along the axial direction of the motor rotor, and a cavity extending along the axial direction is arranged on the shaft body.

Optionally,

The cavity extends from the end of the shaft away from the magnetic part to the end of the shaft adjacent to the magnetic part; or

The cavity extends from the end of the shaft body away from the magnetic part towards the magnetic part and is spaced from the end of the shaft body adjacent to the magnetic part; or

The cavity includes a first cavity and a second cavity spaced from the first cavity.

Optionally, the first cavity extends from one end of the shaft body away from the magnetic portion toward the other end of the shaft body, and the second cavity extends from one end of the shaft body adjacent to the magnetic portion toward the other end.

Optionally, the shaft body includes a first shaft body disposed at the first end of the magnetic part along the axial direction of the motor rotor, the motor rotor further includes a sleeve connected to the first shaft body, and the magnetic part is sleeved in the sleeve .

Optionally, the motor rotor further includes a first flow channel for discharging gas in the sleeve when the magnetic part is sheathed in the sleeve.

Optionally, the first flow channel includes:

a cavity provided on the first shaft body; and/or

The first hole provided on the magnetic part extends from one end of the magnetic part along the axial direction of the motor rotor to the other end.

Optionally, the first flow channel includes a cavity provided on the first shaft body, the cavity and the inner cavity of the sleeve are spaced apart, and the first flow channel also includes an inner cavity and a cavity provided on the first shaft body and communicated with the sleeve. The second channel of the cavity.

Optionally, the shaft body further includes a second shaft body disposed at the second end of the magnetic portion along the axial direction of the motor rotor, and the second shaft body is at least partially sleeved in the sleeve.

Optionally, the motor rotor further includes a second flow channel for discharging gas in the sleeve when the second shaft body is sleeved into the sleeve.

Optionally, the second flow channel includes:

a cavity provided on the second shaft body; and/or

A first hole arranged on the magnetic part and a cavity arranged on the first shaft body.

Optionally,

The first shaft body and the sleeve are integrally formed; or

The first shaft body is at least partially sleeved in the sleeve.

According to another aspect of the present application, there is also provided a compressor including the above-mentioned motor rotor.

Optionally, the compressor further includes:

a centrifugal impeller, connected to the end of the shaft body away from the magnetic part; and

The diffuser is used to compress the refrigerant accelerated by the centrifugal impeller.

Optionally, the compressor further includes an air suspension bearing for carrying the rotor of the motor.

According to another aspect of the present application, there is also provided an air-conditioning apparatus including the above compressor.

By applying the technical solution of the present application, the shaft body of the motor rotor is provided with a cavity, which improves the problem of the low critical speed of the motor rotor caused by the heavy weight in the prior art.

Other features and advantages of the present invention will become apparent from the following detailed description of exemplary embodiments of the present invention with reference to the accompanying drawings.

Description of drawings

In order to explain the embodiments of the present invention or the technical solutions in the prior art more clearly, the following briefly introduces the accompanying drawings that need to be used in the description of the embodiments or the prior art. Obviously, the accompanying drawings in the following description are only These are some embodiments of the present invention, and for those of ordinary skill in the art, other drawings can also be obtained from these drawings without any creative effort.

1 shows a schematic structural diagram of a compressor motor rotor according to an embodiment of the present invention;

FIG. 2 shows a schematic structural diagram of a compressor motor rotor according to an optional embodiment of the present invention;

Figure 3 shows an exploded view of a compressor motor rotor of another alternative embodiment of the present invention; and

FIG. 4 shows a schematic structural diagram of a compressor according to an embodiment of the present invention.

In the picture:

1. Magnetic part; 2. Shaft body; 3. Cavity; 4. Sleeve; 5. First channel; 6. Second channel; 7. Mandrel; 8. Centrifugal impeller; 9. Diffuser; 10. Volute; 11. Bearing support; 12. Bearing.

Detailed ways

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, but not all of the embodiments. The following description of at least one exemplary embodiment is merely illustrative in nature and is in no way intended to limit the invention, its application, or uses. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

FIG. 1 shows a schematic structural diagram of the motor rotor of the compressor of this embodiment. As shown in FIG. 1 , in this embodiment, the motor rotor of the compressor includes a magnetic part 1 for rotating under the action of the energized coil and a shaft connected to the magnetic part 1 and extending away from the magnetic part 1 along the axial direction of the motor rotor Body 2, the shaft body 2 is provided with a cavity 3 extending along its axial direction.

The motor rotor of the compressor of this embodiment is provided with a cavity 3 extending along its axial direction, and the weight of the electronic rotor is reduced, which is beneficial to increase the maximum rotational speed of the motor rotor.

In this embodiment, the cavity 3 extends from the end of the shaft body 2 away from the magnetic part 1 to the end of the shaft body 2 adjacent to the magnetic part 1 .

As shown in FIG. 2, in another embodiment, the cavity includes a first cavity 3a and a second cavity 3b spaced from the first cavity 3a. Between the first cavity 3a and the second cavity 3b is a solid shaft body, and the solid shaft body plays a supporting role, which is beneficial to improve the structural strength of the motor rotor.

As shown in FIG. 3 , in another embodiment, the cavity 3 extends from the end of the shaft body 2 away from the magnetic part 1 toward the magnetic part 1 and is spaced apart from the end of the shaft body 2 adjacent to the magnetic part 1 . Between 3 and the magnetic part 1 is a solid shaft.

The shaft body 2 includes a first shaft body 2a arranged at the first end of the magnetic part 1 along the axial direction of the motor rotor. The motor rotor also includes a sleeve 4 connected with the first shaft body 2a. The magnetic part 1 is sleeved on the sleeve. inside the barrel 4.

In this embodiment, the sleeve 4 and the first shaft body 2a are integrally formed in this embodiment. In some other optional embodiments, part or all of the first shaft body 2 a is sleeved in the sleeve 4 .

The shaft body 2 further includes a second shaft body 2b disposed at the second end of the magnetic part 1 along the axial direction of the motor rotor, and the second shaft body 2b is at least partially sleeved in the sleeve 4 .

The motor rotor further includes a first flow channel for discharging the gas in the sleeve 4 when the magnetic part 1 is sleeved into the sleeve 4 .

The first flow channel includes a cavity 3 provided on the first shaft body 2a. The cavity 3 on the first shaft body 2a extends from one end of the first shaft body 2a adjacent to the magnetic part 1 to the other end. During the process of shrink-fitting the magnetic part 1 into the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 on the first shaft body 2a.

In some embodiments, the cavity 3 on the first shaft body 2a extends from one end of the first shaft body 2a adjacent to the magnetic part 1 toward the other end, and the first shaft body 2a is further provided with a connection for connecting the cavity 3 and the shaft body A through hole in the outer space of 2 , optionally extending along the radial direction of the shaft body 2 . The above-mentioned cavity 3 does not have to extend to the end of the first shaft body 2a adjacent to the magnetic part 1. During the process of shrinking the magnetic part 1 into the sleeve 4, the gas in the sleeve 4 passes through the first shaft body 2a. The upper cavity 3 and the above-mentioned through holes are discharged.

The motor rotor further includes a second flow channel for discharging the gas in the sleeve 4 when the second shaft body 2b is sheathed into the sleeve 4 .

The second flow channel includes a cavity 3 provided on the second shaft body 2b. The cavity 3 on the second shaft body 2b extends from one end of the second shaft body 2b adjacent to the magnetic part 1 toward the other end. During the process of shrink-fitting the second shaft body 2b into the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 provided on the second shaft body 2b.

In some embodiments, the cavity 3 extends from one end adjacent to the magnetic part 1 toward the other end, and the second shaft body 2b is further provided with a through hole communicating with the outer space of the shaft body 2 of the cavity 3 . Optionally, the through hole extends along the radial direction of the second shaft body 2 . During the process of shrink-fitting the second shaft body 2b into the sleeve 4, the gas in the sleeve 4 is discharged through the cavity 3 and the through hole provided on the second shaft body 2b.

In some embodiments, the cavity 3 extends from the end of the second shaft body 2b away from the magnetic part 1 toward the magnetic part 1, the cavity 3 is spaced from the magnetic part 1, and the cavity 3 and the solid shaft body of the magnetic part 1 Equipped with exhaust vents.

FIG. 2 shows a schematic structural diagram of a motor rotor according to another optional embodiment. The motor rotor of this embodiment includes a first flow channel for discharging gas in the sleeve 4 when the magnetic part 1 is heat-fitted into the sleeve 4 , the first flow channel includes a first channel 5 provided on the magnetic part 1 , and the first channel 5 extends from one end of the magnetic part 1 along the axial direction of the motor rotor to the other end. During the process of shrink-fitting the magnetic part 1 into the sleeve 4 , the gas in the sleeve 4 can be discharged through the first hole 5 on the magnetic part 1 .

As shown in FIG. 2 , the cavity 3 provided on the first shaft body 2a includes a first cavity 3a and a second cavity 3b spaced from the first cavity 3a.

The motor rotor also includes a second flow channel for discharging the gas in the sleeve 4 during the process of inserting the second shaft body 2b into the sleeve 4, and the second flow channel includes a cavity 3 provided on the second shaft body 2b , the cavity 3 extends from one end of the second shaft body 2b adjacent to the magnetic part 1 to the other end.

In some embodiments, the second shaft body 2 b is provided with a through hole for communicating the cavity 3 and the external space of the shaft body 2 . The cavity 3 on the second shaft body 2b extends from one end adjacent to the magnetic part 1 toward the other end, and the cavity 3 may not necessarily extend to the end of the second shaft body 2b away from the magnetic part 1 .

FIG. 3 shows a schematic structural diagram of a motor rotor of another optional embodiment. The motor rotor of this embodiment includes a first flow channel for discharging the gas in the sleeve 4 when the magnetic part 1 is heat-fitted into the sleeve 4 , The first flow channel includes a cavity 3 provided on the first shaft body 2 a and a second hole 6 for communicating the cavity 3 and the inner cavity of the sleeve 4 .

In this embodiment, the cavity 3 on the first shaft body 2a extends from the end of the first shaft body 2a away from the magnetic part 1 toward the magnetic part 1. The cavity 3 is spaced from the inner cavity of the sleeve 4, and the cavity 3 and The solid shaft body between the inner cavities of the sleeve 4 is provided with a second hole 6 , and both ends of the second hole 6 communicate with the cavity 3 and the inner cavity of the sleeve 4 respectively.

During the process of inserting the magnetic part 1 into the sleeve 4, the gas in the sleeve 4 is discharged through the second hole 6 and the cavity 3 provided on the first shaft body 2a.

In some embodiments, the second flow channel for exhausting gas when the second shaft body 2b is sleeved into the sleeve 4 includes a first hole provided on the magnetic part 1 and a hollow space provided on the first shaft body 2a Cavity 3.

According to another aspect of the present invention, a compressor is also provided, and FIG. 4 shows a schematic structural diagram of the compressor of this embodiment. As shown in FIG. 4 , the compressor of this embodiment includes a motor rotor, and the motor rotor includes a magnetic part 1 and a shaft body 2 connected to the magnetic part 1 .

The compressor also includes a centrifugal compression part driven by the motor rotor. The centrifugal compression part includes a centrifugal impeller 8 connected to the end of the motor rotor, a diffuser 9 for compressing the refrigerant accelerated by the centrifugal impeller therein, and a volute 10 for discharging the compressed refrigerant.

As shown in FIG. 4 , the compressor also includes a mandrel 7 . The first end of the mandrel 7 is inserted into the upper cavity of the shaft body 2 and is connected with the solid shaft body section of the shaft body 2 . The centrifugal impeller 8 is fixed on the mandrel 7 the second end.

The centrifugal compression part includes a first centrifugal compression part provided at a first end of the motor rotor and a second centrifugal compression part provided at a second end of the motor rotor. The suction port of the second centrifugal compression part communicates with the exhaust port of the first centrifugal compression part, and the second centrifugal compression part is used for compressing the refrigerant compressed by the first centrifugal compression part.

The compressor also includes a bearing support 11 and a bearing 12 mounted on the bearing support 11, and the bearing 12 is used to carry the motor rotor. The bearing 12 is an air suspension bearing. Preferably, the air suspension bearing is a dynamic pressure air suspension bearing.

1 to 4, the motor rotor of the compressor of this embodiment is mainly composed of three sections: a first shaft body 2a, a magnetic part 1 and a second shaft body 2b, wherein the middle section is the magnetic part 1, the first shaft body 2a and the second shaft body 2b are provided with an axially extending cavity 3. The overall mass of the motor rotor is reduced, thereby increasing the critical speed of the rotor and increasing the bearing capacity of the bearing.

The compressor of this embodiment is a two-stage dynamic pressure air suspension centrifugal compressor. The compressor includes a first compression part, a second compression part for compressing the refrigerant compressed by the first compression part, a motor for driving the first compression part and the second compression part, and a circulating air supply self-cooling system. The circulating air supply self-cooling system provides refrigerant for cooling and/or lubricating the bearing 12 in the compressor cavity.

The motor rotor system of the compressor mainly includes a centrifugal impeller 8 of the first compression part, a hollow first shaft body 2a, a magnetic part 1, a hollow second shaft body 2b, a centrifugal impeller 8 of the second compression part, and a thrust bearing thrust body. The shaft body 2 of the motor rotor of the compressor includes a hollow structure and a solid structure. The motor rotor of this structure type can be applied to rotating machinery such as centrifugal refrigeration compressors and screw refrigeration compressors.

The bearing involved in the scheme can be a sliding bearing, a rolling bearing, a magnetic suspension bearing or an air suspension bearing. Considering the oil-free environmental protection structure is simple, the air suspension bearing is preferred.

The schematic diagram of the new three-section hollow high-speed rotor is shown in Figure 2. The motor rotor is mainly composed of three sections: the first shaft body 2a, the magnetic part 1 and the second shaft body 2b. The left and right shaft bodies 2 are processed into a hollow structure, and the middle is The integral magnetic part 1 omits the intermediate mandrel, which is beneficial to simplify the structure and reduce assembly. The first shaft body 2a at the left end is processed into a two-section hollow structure, the left end is a cooling gas channel, and the right end is a hollow sleeve for assembling the magnetic part 1 . Or the second shaft body 2b at the right end is processed into a structure similar to the first shaft body 2a; the solid part of the first shaft body 2a at the left end can be set away from the magnetic part 1, and the first hole 5 is machined in the center of the magnetic part 1, A hole can be a smooth hole or a threaded hole. The number of the first holes 5 is reasonably arranged according to the spatial structure. Similarly, the second shaft body 2b at the right end can use the same structure as the first shaft body 2a. The hollow structure of the first shaft body 2a and the second shaft body 2b at the left and right ends can also be machined with a full hole or a small hole or threaded hole structure in the solid part, but the diameter of the hole needs to be strictly controlled to prevent the shaft and the magnetic part 1 The contact area is too small to damage the magnetic part 1, that is, D hole≤(1/2)D magnetic part 1. The volume of the cavity 3 of the two shaft bodies 2 remains the same or differs by the volume of the sleeve segment, or is adjusted by the solid section of the shaft body 2 so that the center of gravity of the motor rotor is close to the center of the whole rotor.

为宜。由于电机转子在热套过程中存在气体无法排除，需要在第一轴体2a或第二轴体2b的实心部分增加小孔排气，孔径为2至3mm。The rotor of the motor is processed separately. By processing the first shaft body 2a, the second shaft body 2b and the magnetic part 1 respectively, the required key dimensions can be effectively guaranteed, the processing complexity is simplified, the rotor inspection is convenient, and the inspection accuracy is improved. . A small hole can be machined in the center of the two sections of shaft body 2 and the magnetic part 1, but due to the influence of the material of the magnetic part 1, the size of the small hole cannot be too large.

appropriate. Since the motor rotor has gas that cannot be eliminated during the shrink-fit process, it is necessary to add small holes for exhaust gas in the solid part of the first shaft body 2a or the second shaft body 2b, and the hole diameter is 2 to 3 mm.

The above structure not only effectively solves the bearing capacity problem of the bearing, but also increases the critical rotational speed of the rotor by reducing the length of the cantilever end, and further improves the working stability and reliability of the motor.

The invention uses the dynamic pressure air suspension bearing, which not only makes the compressor not need to use lubricating oil and control system, but also makes the compressor more environmentally friendly and simpler in structure; at the same time, it also solves the difficult problem of the integrated processing and inspection of the compressor rotor, and effectively improves the rotor The critical speed can ensure the reliability and safety of the shaft system and reduce the maintenance cost of the compressor.

The above are only exemplary embodiments of the present invention, and are not intended to limit the present invention. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention. Inside.

Claims (15)

1. A motor rotor, characterized in that, comprising: a magnetic part (1) for rotating under the action of an energized coil; and A shaft body (2) is connected to the magnetic part (1) and extends away from the magnetic part (1) along the axial direction of the motor rotor, and the shaft body (2) is provided with a shaft extending along the axial direction of the shaft body (2). cavity (3). 2. The motor rotor according to claim 1, characterized in that, The cavity (3) extends from the end of the shaft body (2) away from the magnetic part (1) to the end of the shaft body (2) adjacent to the magnetic part (1); or The cavity (3) extends from the end of the shaft body (2) away from the magnetic part (1) towards the magnetic part (1), and is adjacent to the magnetic part (1) of the shaft body (2). one end of part (1) is spaced apart; or The cavity (3) includes a first cavity (3a) and a second cavity (3b) spaced from the first cavity (3a). 3 . The motor rotor according to claim 2 , wherein the first cavity ( 3 a ) is directed from the end of the shaft body ( 2 ) away from the magnetic part ( 1 ) toward the shaft body ( 3 . 2) extends from the other end, and the second cavity (3b) extends from one end of the shaft body (2) adjacent to the magnetic part (1) toward the other end. 4. The motor rotor according to claim 1, wherein the shaft body (2) comprises a first shaft provided at a first end of the magnetic part (1) along the axial direction of the motor rotor A body (2a), the motor rotor further comprises a sleeve (4) connected to the first shaft body (2a), and the magnetic part (1) is sleeved in the sleeve (4). 5 . The motor rotor according to claim 4 , further comprising a motor for discharging gas in the sleeve ( 4 ) when the magnetic part ( 1 ) is sheathed into the sleeve ( 4 ). 6 . the first channel. 6. The motor rotor according to claim 5, wherein the first flow channel comprises: the cavity (3) provided on the first shaft body (2a); and/or The first hole (5) provided on the magnetic part (1) extends from one end of the magnetic part (1) along the axial direction of the motor rotor to the other end. 7 . The motor rotor according to claim 5 , wherein the first flow channel comprises a cavity ( 3 ) provided on the first shaft body ( 2 a ), and the cavity ( 3 ) is connected to the The inner cavity of the sleeve (4) is arranged at intervals, and the first flow channel further includes a second channel which is arranged on the first shaft body (2a) and communicates with the inner cavity of the sleeve and the cavity (3). orifice (6). 8 . The motor rotor according to claim 4 , wherein the shaft body ( 2 ) further comprises a second shaft body provided at the second end of the magnetic portion ( 1 ) along the axial direction of the motor rotor. 9 . (2b), the second shaft body (2b) is at least partially sleeved in the sleeve (4). 9. The motor rotor according to claim 8, characterized in that it further comprises a device for discharging into the sleeve (4) when the second shaft body (2b) is sleeved into the sleeve (4) the second flow channel of the gas. 10. The motor rotor according to claim 9, wherein the second flow channel comprises: the cavity provided on the second shaft body (2b); and/or A first hole (5) provided on the magnetic part (1) and a cavity (3) provided on the first shaft body (2a). 11. The motor rotor according to claim 4, characterized in that, The first shaft body (2a) and the sleeve (4) are integrally formed; or The first shaft body (2a) is at least partially sleeved in the sleeve (4). 12. A compressor, characterized in that the compressor comprises the motor rotor of any one of claims 1 to 11. 13. The compressor of claim 12, wherein the compressor further comprises: a centrifugal impeller (8) connected to the end of the shaft body (2) away from the magnetic part (1); and A diffuser (9) for compressing the refrigerant accelerated by the centrifugal impeller (8). 14. The compressor of claim 12, further comprising an air suspension bearing for carrying the motor rotor. 15. An air conditioner, characterized by comprising the compressor according to any one of claims 12 to 14.

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