JP2730659B2 - Scroll compressor - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a scroll compressor and, more particularly, to applying a back pressure to an orbiting scroll. 2. Description of the Related Art In recent years, scroll compressors that have been put into practical use with the development of machine tools and have been receiving attention as compressors having low vibration and low noise characteristics are disclosed in, for example, Japanese Patent Application Laid-Open No.
As shown in Japanese Patent No. 49386, the suction chamber is located at the outer periphery of the spiral compression chamber, the discharge port is provided at the center, and the flow of the compressed fluid is unidirectional, so that the fluid resistance during high-speed operation is low. It is generally well known that they are small and have high compression efficiency. Further, as shown in Japanese Patent Application Laid-Open No. Sho 59-49386, this type of compressor having a high-pressure gas-sealed shell structure is proposed as shown in FIG. By setting, lubrication of each sliding portion was configured as follows while reducing the axial thrust force acting on the orbiting scroll. [0006] That is, in FIG. 6, the fixed scroll wrap 123 includes a main body frame 1 that supports the drive shaft 105.
The orbiting scroll wrap 116 is fixed to a lap support disk 115, and the orbiting scroll wrap 116 is fixed to the back pressure chamber 120 between the end plate 121 and the main body frame 102 in the axial direction by a small amount. The back pressure chamber 120 is arranged in a play state with a gap, and the back pressure chamber 120 is located outside the back pressure chamber A.
120a is rotatably supported via an Oldham ring 118 having a function of partitioning into an inner back pressure chamber B120b and a function of preventing rotation.
A revolving motion is performed by a drive shaft 105 having an eccentric part and an eccentric part. The gas sucked and compressed is supplied to the closed shell 101.
Discharge inside. The lubricating oil separated from the discharge gas is collected in an oil reservoir 109 at the bottom of the sealed shell 101, and the drive shaft 105
The oil is introduced into the back pressure chamber 120 at a high pressure by using a centrifugal pumping action through an oil hole 106 opened at the lower end of the oil pump and provided in an eccentric state and a bearing portion supporting the drive shaft 105. [0005] Further, the lubricating oil, which has been reduced to an intermediate pressure between the discharge pressure and the suction pressure through the minute gap of the sliding portion of the Oldham ring 118, flows into the back pressure chamber A120a, and then flows into the back pressure chamber A120a.
Each of the sliding portions is lubricated in the process of flowing into the suction chamber 122 through the fine hole balance passage 126 provided in the suction passage 21. [0006] However, in the above-described configuration in which only the sliding gap of the Oldham ring 118 is used as a reduced pressure oil supply passage from the inside of the back pressure chamber B120b to the back pressure chamber A120a as shown in FIG. The unevenness of the sliding gap causes variations in the resistance of the throttle passage, making it impossible to properly secure the intermediate pressure in the back pressure chamber A120a, resulting in excessive or insufficient back pressure biasing force to the orbiting scroll. As a result, input loss due to axial excessive contact between the orbiting scroll and fixed scroll and gas leakage during compression due to insufficient axial contact force are caused. Further, the lubrication passes through the sliding gap unevenly due to the variation in the sliding gap of the Oldham ring 118. As a result, the lubricating oil temperature distribution in the back pressure chamber B120b becomes non-uniform, and there is a problem that the thermal distortion of the orbiting scroll and the non-uniform thermal expansion cause a partial expansion of the compression chamber gap. In view of the above, the present invention provides an oil supply passage for providing a uniform temperature distribution of the lubricating oil in the back pressure chamber of the orbiting scroll, thereby ensuring an appropriate urging force to the orbiting scroll and sealing the compression chamber gap. An object of the present invention is to provide a scroll compressor which has excellent durability and compression efficiency. In order to solve the above-mentioned problems, a scroll compressor according to the present invention has a back pressure chamber of an orbiting scroll disposed at the center of a lap support disk of the orbiting scroll and has a discharge pressure. And a back pressure chamber C20c in the lubricating oil area, and a back pressure chamber B20b and a back pressure chamber A20a in the lubricating oil area arranged outside the back pressure chamber C20c and corresponding to the suction pressure. At the same time, a back pressure chamber A20a communicating with the suction chamber is disposed between the end plate of the fixed scroll and the thrust bearing seat of the main body frame to accommodate the lap support disk, and the back pressure chamber B20b supplies oil to the thrust bearing seat from the inside. The back pressure chamber B20b and the back pressure chamber A are arranged to secure the lubricating oil.
20a is communicated with a plurality of balance passages that are alternately opened by the swiveling motion of the lap support disk, and the balance passages are opposed to the center of one of the back pressure chambers A20a and B20b.
And arranged at substantially opposite positions. According to the present invention, the above structure reduces the pressure equivalent to the suction pressure.
Back pressure chamber C20c that has been depressurized and has flowed into the back pressure chamber B20b.
Oil is exchanged with the orbiting motion of the orbiting scroll.
Back pressure through passages that are open to each other and
After flowing into the chamber A20a, the back pressure chamber A20a has a uniform temperature.
It becomes the lubricating oil atmosphere of the cloth. This lubricating oil is the lap support disk
Wrap support by lubricating and cooling the outer sliding part of
Non-uniform thermal deformation of the disk is reduced,
Realization of smooth swivel sliding, partial expansion of compression chamber gap and
Silent compression operation with no shrinkage and no collision between sliding parts
Rolls are obtained. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A scroll compressor according to one embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a longitudinal sectional view of a scroll refrigerant compressor according to one embodiment of the present invention,
FIG. 2 is a detailed explanatory view of a portion B in FIG. In FIG. 1, 1 is a closed shell, 2 is a body frame press-fitted and fixed in the closed shell 1, 3 and 4 are bearings provided at the center of the body frame 2, and 5 are bearings 3 and 4.
A drive shaft provided with an oil hole 7 in communication with the oil hole 6 at a position opposite to the oil hole 6 supported and penetrated by the oil hole 6, an eccentric shaft portion 8 is provided at an upper end thereof, and a closed shell 1 is provided at a lower end thereof. Extends to the bottom of the oil reservoir 9 and is immersed. As shown in FIG. 2, the upper end of the oil hole 6 has
A balance passage 50 having a throttle portion is provided. In the balance passage 50, a steel ball 41 and a coil spring 42 c which constantly urges the steel ball 41 toward the opening end of the oil hole 6 and a narrower hole than the oil hole 6. An oil supply passage control device including a cap 51 having a passage is disposed, and is configured to narrow the opening at both ends of the balance passage 50. A motor 10 has a rotor 11 fixed to the drive shaft 5 and a stator 12 fixed to the closed shell 1 by press fitting. An eccentric shaft 8 is connected to the center of the bearing 1.
3, the eccentric shaft portion 8 and the bearing portion 13 provide a back pressure chamber C20c.
The orbiting scroll disk 16 of the orbiting scroll 14 is integrally formed with an orbiting scroll wrap 16 standing upright on the upper surface thereof, and the lower surface thereof is supported by a thrust bearing seat 17 protruding from an opening at the upper end of the main body frame 2. . The orbiting scroll wrap 16 has a spiral planar shape, and its longitudinal section is rectangular, and is parallel to adjacent orbiting scroll wraps 16. The Oldham ring 18 for preventing rotation is provided with parallel key-shaped keys orthogonal to each other on both surfaces of a flat ring, and is provided between the lap support disk 15 and the thrust bearing seat 17. . This Oldham ring 18
The key portion on the upper surface side is fitted in a key groove (not shown) provided on the back surface of the lap support disk 15, and the key portion on the lower surface side is fitted in a key groove 19 provided on the thrust bearing seat 17. Due to the rotation of the shaft 5, the bearing portion 13 of the lap support disk 15 makes a circular motion around the axis of the drive shaft 5, and the orbiting scroll wrap 16 makes an orbiting motion. On the upper end surface of the main body frame 2, the end plate 21 of the fixed scroll 34 which covers the upper end opening hole and serves as the back pressure chamber 20 of the lap support disk 15 is provided with a thrust bearing seat 17.
At the same time, the wrap support disk 15 of the orbiting scroll 14 is mounted so as to be sandwiched by the minute gap, and forms a back pressure chamber 20 of the orbiting scroll 14. The back pressure chamber 20 is partitioned by a lap support disk 15, and is divided into a back pressure chamber A20a on the outer peripheral surface side and a back pressure chamber B20b on the back side. An annular suction chamber 22 is provided inside the head plate 21.
Is provided. A discharge port 25 having a discharge space 24 inside the closed shell 1 is provided inside the suction chamber 22 at the center of the spiral of the fixed scroll wrap 23 having the same shape and dimensions parallel to the orbiting scroll wrap 16. A balance passage 26 of a small hole opened on the sliding surface with the lap support disk 15 and communicating the suction chamber 22 and the back pressure chamber A20a, and a balance of a small hole communicating the back pressure chamber A20a and the back pressure chamber B20b. A passage 27 is provided in the end plate 21 and the thrust bearing seat 17, and the lap support disk 15 is moved in a predetermined turning angle range (in the process of increasing the suction volume of the outermost compression chamber).
Passage 26 and balance passage 27 only when
The balance passage 27a provided in the thrust bearing seat 17 is closed so that the
And the balance passage 27a are connected to the back pressure chamber A20a or B20
b are disposed at positions substantially opposite to each other with respect to the center of either one . As shown in FIG. 2, a case 40 is press-fitted into the end plate 21 in the middle of the balance passage 26 so as to sandwich the openings at both ends of the balance passage 26, and is provided upstream of the center of the passage. A steel ball 41 is mounted on the downstream side, and a coil spring 42 is mounted on the downstream side to form an oil supply passage control device 43. The coil spring 42 acts on the steel ball 41 based on a pressure difference between the back pressure chamber 20 and the suction chamber 22. Steel ball 41 against back pressure
And the steel ball 41 is constantly urged to continuously change the opening degree of the balance passage 26. A suction pipe 28 penetrating the sealing shell 1 from the side is connected to the annular suction chamber 22, and a discharge pipe 29 opening toward the inner surface of the sealing shell 1 is provided on the upper surface of the sealing shell 1. It is connected. A groove 30 is provided on the outer surface of the main body frame 2 which is press-fitted and fixed to the closed shell 1. The groove 30 connects the discharge space 24 on the end plate 21 side of the closed shell 1 to the motor 10. ing. The operation of the scroll refrigerant compressor configured as described above will be described below with reference to FIGS. 1 and 2. FIG. 1 is a longitudinal sectional view of a scroll refrigerant compressor,
FIG. 2 is a detailed view of a portion B in the vicinity of the balance passage 50 in FIG. 1. When the rotor 11 of the motor 10 rotates and the drive shaft 5 is driven to rotate, the orbiting scroll 14 makes a orbiting motion, The refrigerant gas is sucked into the suction chamber 22 through 28, and the refrigerant gas is confined in a compression chamber formed between the orbiting scroll wrap 16 and the fixed scroll wrap 23, and is compressed with the orbiting movement of the orbiting scroll wrap 16, A part of the lubricating oil discharged from the discharge port 25 into the discharge space 24 and separated from the refrigerant gas by its own weight or the like is separated from the refrigerant gas by way of the groove 30 between the closed shell 1 and the main body frame 2 and the like. The remaining lubricating oil is discharged to the external refrigeration cycle through the discharge pipe 29 together with the discharged refrigerant gas. On the other hand, the difference between the oil reservoir 9 on the high pressure side and the suction chamber 22 on the low pressure side via the back pressure chamber 20 formed separately from the discharge space 24 by the end plate 21 of the fixed scroll 34 and the body frame 2. Pressure lubrication is performed as follows. That is, for a while after the cold start of the compressor, the pressure differences between the back pressure chamber 20 and the suction chamber 22 and between the oil reservoir 9 and the back pressure chamber 20 are small. The opening of the passage 50 is narrowed to the minimum state. On the other hand, the highly viscous lubricating oil in the oil reservoir 9 at the bottom of the closed shell 1 filled with the discharged refrigerant gas supports the oil holes 6, 7 provided in the drive shaft 5, the balance passage 50, and the drive shaft 5. The differential pressure is supplied to the back pressure chambers 20b and 20c via the minute gaps between the bearings 3 and 4 and the bearing 13 of the eccentric shaft 8. After passing through the balance passage 50, the pressure is reduced and flows into the back pressure chamber 20c.
The lubricating oil that is depressurized again when passing through the sliding gap 3 and the lubricating oil that is depressurized when passing through the sliding gap between the bearings 3 and 4 are joined to form a discharge pressure and suction pressure. Inflow at intermediate pressure. Further, the lubricating oil is depressurized through alternately opening and closing narrow passages 27 , 27a intermittently opened and closed by the orbiting motion of the lap support disk 15 of the orbiting scroll 14, and is intermittently supplied to the back pressure chamber A20a. The lubricating oils are provided at positions opposite to each other.
Flows alternately into the back pressure chamber A0a from the impedance passages 27 and 27a .
By doing so, the back pressure chamber A20a and the back pressure chamber B20b
Lubricating oil is evenly distributed and cools the sliding surface evenly.
The temperature distribution of the lap support disk 15 is averaged
become. As the pressure in the back pressure chamber A20a rises, the opening of the balance passage 26 gradually widens, and the lubricating oil in the back pressure chamber A20a is intermittently supplied to the suction chamber 22 little by little, and is again discharged together with the suction refrigerant gas. You. As time elapses after the start of the compressor, the discharge pressure increases, the compression chamber pressure also increases, and the thrust load acting on the orbiting scroll 14 increases during gas compression. Back pressure chamber 20 via bearing 13
The amount of lubricating oil flowing into the orifice increases, the pressure in the back pressure chamber 20 increases, the back pressure chamber biasing force on the orbiting scroll 14 is increased, and the thrust force acting on the orbiting scroll 14 is reduced.
The orbiting scroll 14 is pressed against the fixed scroll 34 with an appropriate force. The oil supply passage control device 43c provided in the balance passage 50 has a steel ball 41 attached to the coil spring 42c by the pressure difference between the oil hole 6 and the back pressure chamber 20c following the rise of the discharge pressure. It moves in the direction away from the opening end of the oil hole 6 against the force, widens the opening of the passage, reduces the degree of pressure reduction of the lubricating oil, and increases the back pressure of the back pressure chambers 20c and 20b. The thrust load acting on the orbiting scroll 14 is reduced against the compression chamber pressure that increases following the increase in the discharge pressure (the discharge gas flows back into the compression chamber and increases the compression chamber distribution pressure). The maximum opening degree of the passage of the oil supply passage control device 43 is limited by the narrow passage provided in the central portion of the cap 51, and excessive lubricating oil flows from the oil reservoir 9 into the back pressure chamber 20. Is preventing. In the event that clogging or the like occurs in the piping system of the refrigeration cycle, the suction pressure drops abnormally, and the discharge pressure rises abnormally, the pressure in the back pressure chamber 20 is excessive compared to the pressure in the compression chamber. In such a case, the opening degree of the throttle passage of the oil supply passage control device 43c is increased to control the pressure of the back pressure chamber 20 within an appropriate range. Naturally, even during a normal operation in which the suction pressure and the discharge pressure are normal, the oil supply passage control device 43c controls the throttle opening of the oil supply passage between the oil reservoir 9 and the back pressure chamber 20, and the back pressure chamber The opening degree of the throttle passage of the oil supply passage between the oil supply passage 20 and the suction chamber 22 is controlled by the oil supply passage control device 43c, whereby the pressure in the back pressure chamber 20 is set according to the suction pressure and the discharge pressure. Also, the scroll refrigerant compressor is incorporated in a heat pump type refrigerating cycle, and immediately after switching from the heating refrigerating cycle to the defrosting refrigerating cycle, the discharge chamber pressure becomes low and the suction chamber pressure becomes high. From this relationship, the refrigerant gas tends to flow backward from the suction chamber 22 to the back pressure chamber 20 via the balance passages 26 , 27 and 27a , but the passage is formed by the check valve action of the steel ball 41 provided in the balance passage 26. It is closed to prevent the refrigerant gas from flowing back to the oil reservoir 9 via the back pressure chamber 20, and to prevent the lubricating oil from flowing out of the back pressure chamber 20 and the bearing sliding surface and seizure of the sliding surface. In the above-described embodiment, the opening on the downstream side of the balance passage 26 is configured to communicate with the end of the coil spring 42. However, as shown in FIG. A configuration in which the fuel supply passage control device 43b is provided in the balance passage 27 as shown in FIG. 5, or a combination thereof, may be used. According to this differential pressure oil supply system, the pressure in the back pressure chamber 20 on the back of the lap support disk 15 can be freely set from a state close to the discharge pressure to a state close to the suction pressure by adjusting the passage resistance of the oil supply passage. . Therefore, the load difference between the back urging force acting on the back of the lap support disk 15 and the gas pressure load in the compression chamber can be freely adjusted, whereby the lap support disk 15 can be pressed against the end plate 21 side. Further, it can be pressed away from the end plate 21 toward the thrust bearing seat 17. In the above embodiment, the lubricating oil has good fluidity, such as during steady operation, and when the required amount of lubricating oil is supplied from the back pressure chamber 20c to the suction chamber 22, the lap supporting disk 15 slides constantly with the end plate 21. When the lubricating oil temperature is low and the fluidity is poor, such as immediately after a cold start, and the required amount of lubricating oil is not supplied from the back pressure chamber 20c to the suction chamber 22, the lap support disk 15 is provided with a thrust bearing seat. The area and the pressure of the back pressure chamber 20 are set so as to always make sliding contact with 17, and the passage openings of the oil supply passage control devices 43 and 43c are set to realize the pressure and the oil supply amount. If the axial clearance of the compression chamber is very small and no special consideration is required for sealing the compression chamber, as apparent from the above description, the passage resistance adjustment of the oil supply passage control devices 43 and 43c is performed. Accordingly, each lubricating oil pressure of the back pressure chamber 20 and each region are set so as to constantly contact the thrust bearing seat 17 so that the orbiting scroll 14 can perform a stable orbiting motion without tilting or axial contact with the fixed scroll 34. Can also be partitioned. Even when the differential pressure between the discharge pressure and the suction pressure is small and the differential pressure oil supply amount is small, the orbiting scroll 14 constantly contacts the thrust bearing seat 17 to perform a stable orbiting motion. Thrust bearing seat 17
, And between the orbiting scroll 14 and the eccentric shaft portion 8 of the drive shaft 5, collision of the sliding surface and intermittent sliding are avoided, and the destruction of the lubricating oil film is prevented, and the durability is improved. In addition, vibration and noise generation are suppressed by the buffering action of the lubricating oil film. In particular, in order to simplify the back pressure chamber 20 and the oil supply passage, the back pressure chamber 20b and the back pressure chamber 20a are set to the suction pressure, and the back pressure chamber 20c is set to the lubricating oil area corresponding to the discharge pressure. Can be set easily. As described above, according to the present invention, the back pressure chamber of the orbiting scroll is disposed at the center of the lap support disk of the orbiting scroll, and the back pressure chamber C20c of the lubricating oil area corresponding to the discharge pressure is provided.
And a back pressure chamber B20b and a back pressure chamber A20a, which are arranged outside the back pressure chamber C20c and are in the lubricating oil area corresponding to the suction pressure, are communicated so that the lubricating oil passes through the back pressure chamber B20b and the back pressure chamber which communicates with the suction chamber. The chamber A20a is arranged between the end plate of the fixed scroll and the thrust bearing seat of the main body frame to accommodate the lap support disk, and the back pressure chamber B20b is arranged to secure the lubricating oil supplied to the thrust bearing seat from the inside, The back pressure chamber B20b and the back pressure chamber A20a are communicated with each other by a plurality of balance passages that are alternately opened by the swirling motion of the lap support disk, and the balance passage is one of the back pressure chambers A20a and B20b.
By disposed in the approximate opposite positions to each other with respect to the center, the lubricating oil from the back pressure chamber C20c which has flowed to the back pressure chamber B20b is reduced to the suction pressure equivalent, along with the orbiting motion of the orbiting scroll alternately And flows into the back pressure chamber A20a through the passages arranged on the opposite sides, so that the back pressure chamber A20a has a lubricating oil atmosphere having a uniform temperature distribution. This lubricating oil lubricates and cools the outer peripheral sliding portion of the lap support disk, thereby reducing uneven thermal deformation of the lap support disk, realizing smooth orbital sliding of the orbiting scroll and partially expanding the compression chamber gap. And shrinkage can be avoided. As a result, there is an effect that the compression chamber is maintained at a small gap to improve compression efficiency and reduce noise and vibration without collision between the sliding parts.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a longitudinal sectional view of a scroll refrigerant compressor according to a first embodiment of the present invention. FIG. 2 is a sectional view of a portion B in FIG. 1. FIG. FIG. 4 is a partial cross-sectional view of a scroll refrigerant compressor showing another embodiment of the present invention. FIG. 5 is a partial cross-sectional view of a scroll refrigerant compressor showing another different embodiment of the present invention. FIG. 6 is a longitudinal sectional view of a different conventional scroll compressor. [Description of References] 1 Sealed shell 2 Body frame 5 Drive shaft 10 Motor 14 Orbiting scroll 15 Wrap support disk 16 Orbiting scroll Wrap 20 Back pressure chamber 21 End plate 22 Suction chamber 23 Fixed scroll wrap 25 Discharge ports 26, 27 Balance passage 34 Fixed scroll 41 Steel 42 coil spring 43 oil passage control device

Claims (1)

(57) [Claims] The orbiting scroll wrap on the wrap support disk that forms part of the orbiting scroll oscillates with the spiral scroll wrap that is formed on one surface of the end plate that forms part of the fixed scroll, and the vortex is formed between the two scrolls. A fixed compression wrap is formed at the center of the fixed scroll wrap, a discharge port is provided, a suction chamber is formed outside the fixed scroll wrap, and the wrap support disk is configured to support a drive shaft. The thrust bearing seat provided on the end plate and the end plate are arranged in a play state, and are adjacent to a back pressure chamber for biasing the orbiting scroll toward the fixed scroll, and the orbiting scroll is prevented from rotating. By engaging with a mechanism, the fluid is compressed using a change in volume of a compression chamber formed between the fixed scroll wrap and the orbiting scroll wrap. A scroll-type compression mechanism having an oil supply passage having an oil reservoir communicating with the discharge port, a back pressure chamber, and a throttle portion sequentially passing through the suction chamber, wherein the back pressure chamber is provided with the lap support. Back pressure chamber C located in the center of the disk and in the lubricating oil area equivalent to the discharge pressure
20c, a back pressure chamber B20b and a back pressure chamber A20a, which are disposed outside the back pressure chamber C20c and are in a lubricating oil area corresponding to the suction pressure, are communicated so that the lubricating oil passes through the suction chamber sequentially. The communicating back pressure chamber A20a is disposed between the end plate and the thrust bearing seat of the main body frame to accommodate the lap support disk, and the back pressure chamber B20b is provided with lubricating oil for supplying the thrust bearing seat from the inside. is arranged to ensure, during said back pressure chamber B20b and the back pressure chamber A20a is communicated with a plurality of balance passage for opening alternately by pivoting movement of the lap supporting disk, said balance passage wherein
To the center of either back pressure chamber A20a or B20b
Scroll compressors located approximately opposite to each other.