CN213928729U

CN213928729U - Scroll compressor

Info

Publication number: CN213928729U
Application number: CN202023089105.9U
Authority: CN
Inventors: 林楚辉; 李拥军; 师海峰; 李春晖
Original assignee: Jinba Intelligent Technology Co ltd
Current assignee: Jinba Intelligent Technology Co ltd
Priority date: 2020-12-18
Filing date: 2020-12-18
Publication date: 2021-08-10
Anticipated expiration: 2030-12-18

Abstract

The utility model provides a scroll compressor, which comprises a shell, a controller, a motor and a fixed scroll, the motor comprises a shell, a movable scroll, a main bearing seat and a support, wherein an air suction cavity is formed in the shell, the movable scroll is arranged in a fixed scroll and meshed with the fixed scroll to form a compression cavity, the mounting end of a crankshaft of the motor is mounted to a controller, the driving end of the crankshaft penetrates through the main bearing seat, the support is mounted to the movable scroll, the main bearing seat is mounted to the fixed scroll and connected with the movable scroll, the support is mounted in the main bearing seat, a first back pressure cavity is formed between the main bearing seat and the support, a second back pressure cavity is formed between the support and the movable scroll, the movable scroll is provided with a back pressure channel which is respectively communicated with the compression cavity and the second back pressure cavity, the crankshaft is provided with a first oil return channel and a second oil return channel, the first oil return channel is respectively communicated with the second back pressure cavity and the first back pressure cavity, and the second oil return channel is respectively communicated with the first back pressure cavity and the air suction cavity. The utility model discloses can realize the circulation of refrigeration oil in the compressor.

Description

Scroll compressor

[ technical field ] A method for producing a semiconductor device

The utility model relates to a compressor, concretely relates to automotive scroll compressor.

[ background of the invention ]

The existing vehicular scroll compressor comprises a machine shell, a controller installed at one end of the machine shell, a motor installed in the machine shell, a fixed scroll installed in the machine shell, a movable scroll, a main bearing seat and a support. The interior of the housing forms a suction chamber. The movable scroll is arranged in the fixed scroll and meshed with the fixed scroll to form a compression chamber. The installation end of the crankshaft of the motor is installed on the controller, and the driving end of the crankshaft penetrates through the main bearing seat and the support and is installed on the movable scroll plate. The main bearing seat is installed on the fixed scroll and connected with the movable scroll, the support is installed in the main bearing seat, a first back pressure cavity is formed between the main bearing seat and the support, and a second back pressure cavity is formed between the support and the movable scroll. The movable scroll plate is provided with backpressure channels which are respectively communicated with the compression cavity and the second backpressure cavity so as to lead compressed gas in the compression cavity into the second backpressure cavity, and the fixed scroll plate and the main bearing seat are provided with backpressure channels which are respectively communicated with the compression cavity and the first backpressure cavity so as to lead compressed gas in the compression cavity into the first backpressure cavity. Because the refrigeration oil for lubrication is mixed in the gas introduced into the second back pressure cavity and the gas introduced into the first back pressure cavity, a small amount of refrigeration oil can be exchanged between the first back pressure cavity, the second back pressure cavity and the corresponding back pressure channel, but along with the operation of the compressor, more refrigeration oil can be accumulated in the first back pressure cavity and the second back pressure cavity, so that the refrigeration oil cannot be smoothly discharged, the oil temperature of the refrigeration oil in the first back pressure cavity and the second back pressure cavity is increased, the cooling effect is influenced, meanwhile, the refrigeration oil quantity at other parts of the compressor is insufficient, and the reliability of the operation of the compressor is influenced.

Accordingly, there is a need for an improved scroll compressor.

[ Utility model ] content

The utility model discloses a main aim at provides a scroll compressor can realize the circulation of refrigeration oil in the compressor, has ensured the reliability of compressor operation.

In order to achieve the above object, the present invention provides a scroll compressor, including a housing, a controller mounted at one end of the housing, a motor mounted in the housing, a fixed scroll mounted in the housing, a movable scroll, a main bearing seat and a bracket, wherein a suction cavity is formed inside the housing, the movable scroll is disposed in the fixed scroll and engaged with the fixed scroll to form a compression cavity, a mounting end of a crankshaft of the motor is mounted to the controller, a driving end of the crankshaft passes through the main bearing seat and the bracket and is mounted to the movable scroll, the main bearing seat is mounted to the fixed scroll and connected to the movable scroll, the bracket is mounted to the main bearing seat, a first back pressure cavity is formed between the main bearing seat and the bracket, and a second back pressure cavity is formed between the bracket and the movable scroll, move the scroll and be equipped with the backpressure passageway that compression chamber and second backpressure chamber communicate respectively, its characterized in that, the bent axle is equipped with first oil return passageway and second oil return passageway, first oil return passageway respectively with second backpressure chamber and first backpressure chamber link to be used for storing up the refrigeration oil in the second backpressure chamber is introduced first backpressure intracavity and carry out the throttle decompression to the refrigeration oil in order providing the required pressure in first backpressure chamber, second oil return passageway respectively with first backpressure chamber and the chamber intercommunication of breathing in are used for storing up the refrigeration oil in the first backpressure chamber is introduced breathe in the intracavity and carry out the throttle decompression to the refrigeration oil in order to provide the refrigeration oil that equals with the pressure of breathing in the intracavity.

As a preferable technical solution, the first oil return passage and the second oil return passage are respectively located at both sides of the crankshaft.

As a preferred technical scheme, the first oil return passage comprises a first loop and a second loop, the first loop is arranged at the end part of the driving end of the crankshaft, the second loop is arranged on the outer wall of the driving end of the crankshaft, the first loop is communicated with the second back pressure cavity, the second loop is communicated with the first back pressure cavity and is used for throttling and reducing pressure of the refrigerating oil so as to provide pressure required by the first back pressure cavity, and the first loop and the second loop are vertically arranged.

Preferably, the first circuit extends in an axial direction of the crankshaft, the second circuit extends in a radial direction of the crankshaft, and the second circuit is connected between both ends of the first circuit.

As a preferable technical scheme, the inner diameter of the first loop is 4-5 mm, and the inner diameter of the second loop is 1.2-1.5 mm.

As a preferred technical scheme, the second oil return passage comprises a third loop and a fourth loop, the third loop is arranged on the outer wall of the driving end of the crankshaft, the fourth loop is arranged on the end portion of the mounting end of the crankshaft, the third loop is communicated with the first back pressure cavity and used for throttling and reducing pressure of the refrigerant oil so as to provide the refrigerant oil with the same pressure as that in the air suction cavity, the fourth loop is communicated with the air suction cavity, and the third loop and the fourth loop are vertically arranged.

Preferably, the third circuit extends in a radial direction of the crankshaft, the fourth circuit extends in an axial direction of the crankshaft, and an end of the third circuit, which is away from the first back pressure chamber, is connected to an end of the fourth circuit, which is away from a mounting end of the crankshaft.

Preferably, the third circuit has an inner diameter of 1-1.2 mm, and the fourth circuit has an inner diameter of 4-5 mm.

As a preferable technical solution, a first shaft seal is arranged in a near-motor end of the main bearing seat, the first shaft seal is sleeved on the periphery of the crankshaft, and a far-motor end of the main bearing seat is mounted on the fixed scroll and connected with the movable scroll through a pin.

As a preferred technical scheme, a second shaft seal is arranged in a motor end, close to the support, of the support, the second shaft seal is arranged on the periphery of the crankshaft, a motor end, far away from the support, of the support is arranged in a motor end, far away from the main bearing seat, of the support, and a sealing ring is arranged between the motor end, far away from the support, of the support and the motor end, far away from the main bearing seat.

The utility model provides a scroll compressor through first oil return passageway and the second oil return passageway that sets up, can realize compression chamber, second backpressure chamber, first backpressure chamber and inhale UNICOM between the chamber, is favorable to the circulation of refrigeration oil in the compressor, has ensured the cooling effect of refrigeration oil in first backpressure chamber, second backpressure intracavity, has ensured the reliability of compressor operation.

[ description of the drawings ]

To further disclose the specific technical content of the present disclosure, please refer to the attached drawings, wherein:

fig. 1 is a schematic structural diagram of a scroll compressor according to an embodiment of the present invention;

FIG. 2 is an exploded view of the scroll compressor shown in FIG. 1;

FIG. 3 is a cross-sectional schematic view of the scroll compressor shown in FIG. 1;

FIGS. 4 and 5 are schematic cross-sectional views of the orbiting scroll, the fixed scroll, the main bearing housing, the bracket and the crankshaft of the scroll compressor shown in FIG. 1;

FIG. 6 is a schematic illustration of a first angle of a crankshaft of the scroll compressor shown in FIG. 1;

FIG. 7 is a schematic illustration of a second angle of the crankshaft of the scroll compressor shown in FIG. 1;

FIG. 8 is a schematic view of a first angled portion of a fixed scroll of the scroll compressor of FIG. 1;

FIG. 9 is a second angled configuration of a fixed scroll of the scroll compressor shown in FIG. 1;

FIG. 10 is a schematic view of a first angled configuration of the orbiting scroll of the scroll compressor shown in FIG. 1;

FIG. 11 is a second angled configuration of the orbiting scroll of the scroll compressor shown in FIG. 1.

Description of the symbols:

scroll compressor 500 shell 10

Intake opening 122 of housing 12

Vent 142 of top lid 14

Controller 16 controller housing 162

Mounting location 1622 first bearing 164

Crankshaft 22 of motor 20

First oil return passage 222 and first circuit 2222

Second circuit 2224 second oil return passage 224

Third circuit 2242 fourth circuit 2244

Eccentric shaft 24 and second bearing 26

Shaft sleeve 28

Fixed scroll 30

Ring portion 34 non-orbiting scroll portion 36

Mounting plate 38 air intake 302

Air outlet 304

End plate 42 of orbiting scroll 40

Orbiting scroll 44 hub 46

Compression chamber 408

Main bearing seat 50 first shaft seal 52

First circlip 56 third bearing 58

Second shaft seal 62 of bracket 60

Second circlip 64

First back pressure chamber 71 and second back pressure chamber 72

Back pressure channel 74

Sealing ring 80

Gasket 90 through hole 94

Pin 100

[ detailed description ] embodiments

Referring to fig. 1, the present embodiment provides a scroll compressor 500, which is a vehicular scroll compressor. The scroll compressor 500 includes a casing 10 and a controller 16 mounted to one end of the casing 10. The enclosure 10 includes a housing 12 and a top cover 14, and the controller 16 includes a controller housing 162 and control components mounted within the controller housing. The controller case 162 and the top cover 14 are mounted to both ends of the case 12, respectively. The housing 12 has a suction port 122 for allowing the refrigerant gas to enter therein, and the top cover 14 has a discharge port 142 for discharging the refrigerant gas. The casing 10 has an intake chamber formed therein, the intake port 122 for taking in refrigerant gas into the intake chamber, and the discharge port 142 for discharging compressed refrigerant gas.

Referring to fig. 2 to 5, the scroll compressor 500 further includes a motor 20 installed in the casing 10, a fixed scroll 30 installed in the casing 10, a movable scroll 40, a main bearing housing 50, and a bracket 60. The operation of the motor 20 is controlled by the control assembly. The fixed scroll 30 is mounted to the top cover 14 by a mounting plate 38.

The fixed scroll 30 has an inlet port 302 (see fig. 2, 8, and 9) and an outlet port 304 (see fig. 9). The air inlet 302 communicates with the suction chamber and the air outlet 304 communicates with the exhaust 142. The orbiting scroll 40 is disposed inside the fixed scroll 30 and meshes with the fixed scroll 30 to form a compression chamber 408. The inlet 302 and outlet 304 ports communicate with the compression chamber 408, respectively. The refrigerant gas entering from the suction port 122 enters the compression chamber 408 through the suction chamber and the inlet 302, is compressed in the compression chamber 408, and is discharged to the outside of the scroll compressor 500 through the outlet 304 and the outlet 142.

The mounting end of the crankshaft 22 of the motor 20 is mounted to a controller housing 162 of the controller 16. Specifically, the controller housing 162 has a mounting location 1622 to which a mounting end of the crankshaft 22 is mounted via a first bearing 164 at the mounting location 1622, the first bearing 164 providing rotational support to the mounting end of the crankshaft 22. The drive end of the crankshaft 22 passes through the main bearing housing 50, the bracket 60 and is mounted to the orbiting scroll 40 to drive the orbiting scroll 40 in rotational motion within the fixed scroll 30. Specifically, the driving end of the crankshaft 22 is provided with an eccentric shaft 24, the eccentric shaft 24 is mounted to the orbiting scroll 40 through a second bearing 26, and the orbiting scroll 40 is driven to perform a rotational motion in the fixed scroll 30 and compress a refrigerant gas by an eccentric motion of the eccentric shaft 24. The second bearing 26 provides rotational support to the drive end of the crankshaft 22. A bushing 28 is provided between the eccentric shaft 24 and the second bearing 26.

The main bearing seat 50 is installed on the fixed scroll 30 and connected with the movable scroll 40, the bracket 60 is installed in the main bearing seat 50, a first back pressure cavity 71 is formed between the main bearing seat 50 and the bracket 60, a second back pressure cavity 72 is formed between the bracket 60 and the movable scroll 40, and the movable scroll 40 is provided with a back pressure channel 74 (see fig. 4) respectively communicated with the compression cavity 408 and the second back pressure cavity 72.

As shown in fig. 2 and 5, the crankshaft 22 is provided with a first oil return passage 222 and a second oil return passage 224. The first oil return passage 222 is respectively communicated with the second back pressure chamber 72 and the first back pressure chamber 71 to introduce the refrigeration oil accumulated in the second back pressure chamber 72 into the first back pressure chamber 71 and throttle and depressurize the refrigeration oil to provide the pressure required by the first back pressure chamber 71, and the second oil return passage 224 is respectively communicated with the first back pressure chamber 71 and the suction chamber to introduce the refrigeration oil accumulated in the first back pressure chamber 71 into the suction chamber and throttle and depressurize the refrigeration oil to provide the refrigeration oil equal to the pressure in the suction chamber.

In actual use, the refrigerant gas enters the suction chamber through the suction port 122, cools the controller 16 and the motor 20, enters the compression chamber 408 from the inlet 302, is compressed, and is discharged to the outside of the scroll compressor 500 from the outlet 304 and the discharge port 142. In the process, the high-pressure gas formed by compressing the refrigerant gas can be introduced into the second back pressure cavity 72 through the back pressure channel 74 and then introduced into the first back pressure cavity 71 through the first oil return channel 222, so that the buoyancy force for attaching the orbiting scroll 40 to the fixed scroll 30 is provided. Meanwhile, the refrigeration oil mixed with the high-pressure gas in the compression chamber 408 can also be introduced into the second back pressure chamber 72 through the back pressure passage 74, along with the operation of the scroll compressor 500, the refrigeration oil stored in the second back pressure chamber 72 is introduced into the first back pressure chamber 71 through the first oil return passage 222, generally, the pressure in the first back pressure chamber 71 is smaller than the pressure in the second back pressure chamber 72, the first oil return passage 222 simultaneously throttles and reduces the pressure of the refrigeration oil to provide the pressure required by the first back pressure chamber 71, the refrigeration oil stored in the first back pressure chamber 71 is introduced into the suction chamber through the second oil return passage 224, generally, the pressure in the suction chamber is smaller than the pressure in the first back pressure chamber 71, and the second oil return passage 224 simultaneously throttles and reduces the pressure of the refrigeration oil to provide the refrigeration oil equal to the pressure in the suction chamber. After the refrigerant oil returns to the suction cavity, the refrigerant oil and the refrigerant gas sucked from the suction port 122 enter the compression cavity 408 through the air inlet 302 of the fixed scroll 30 to be compressed, so that the circulation of the refrigerant oil in the scroll compressor 500 is realized, the refrigeration effect of the refrigerant oil in the first back pressure cavity 71 and the second back pressure cavity 72 is ensured, and the operation reliability of the scroll compressor 500 is ensured.

The first oil return passage 222 and the second oil return passage 224 are located on both sides of the crankshaft 22, respectively.

In the present embodiment, as shown in fig. 5 and 6, the first oil return passage 222 includes a first loop 2222 disposed at the end of the driving end of the crankshaft 22 and a second loop 2224 disposed on the outer wall of the driving end of the crankshaft 22, the first loop 2222 is communicated with the second back pressure chamber 72, and the second loop 2224 is communicated with the first back pressure chamber 71 for throttling and depressurizing the refrigerant oil to provide the pressure required by the first back pressure chamber 71. The first loop 2222 and the second loop 2224 are vertically arranged.

The first circuit 2222 extends in the axial direction of the crankshaft 22, the second circuit 2224 extends in the radial direction of the crankshaft 22, and the second circuit 2224 is connected between both ends of the first circuit 2222. Through the structure, the throttling and pressure reducing effects can be achieved, and a certain pressure difference is generated while the first back pressure cavity 71 and the second back pressure cavity 72 are communicated.

The first loop has an internal diameter of 4-5 mm and the second loop has an internal diameter of 1.2-1.5 mm.

As shown in fig. 5 and 7 in conjunction, the second oil return passage 224 includes a third circuit 2242 provided on an outer wall of the drive end of the crankshaft 22 and a fourth circuit 2244 provided on an end of the mounting end of the crankshaft 22, the third circuit 2242 communicating with the first back pressure chamber 71 for throttling and depressurizing the refrigerant oil to supply the refrigerant oil equal to the pressure in the suction chamber, and the fourth circuit 2244 communicating with the suction chamber. Third circuit 2242 and fourth circuit 2244 are vertically disposed.

The third circuit 2242 extends in the radial direction of the crankshaft 22, the fourth circuit 2244 extends in the axial direction of the crankshaft 22, and an end of the third circuit 2242 remote from the first back pressure chamber 71 is connected to an end of the fourth circuit 2244 remote from the mounting end of the crankshaft 22.

The third loop has an inner diameter of 1-1.2 mm and the fourth loop has an inner diameter of 4-5 mm.

As shown in fig. 2 and 3, a first shaft seal 52 is disposed in a side of the main bearing housing 50 close to the motor, and the first shaft seal 52 is sleeved on an outer circumference of the crankshaft 22. The first shaft seal 52 is used to effect a seal between the first back pressure chamber 71 and the suction chamber. The distal motor end of the main bearing housing 50 is mounted to the fixed scroll 30 and is connected to the orbiting scroll 40 by a pintle 100 to effect support of the fixed scroll 30 and orbiting scroll 40. A second shaft seal 62 is provided in the end of the bracket 60 near the motor, and the second shaft seal 62 is fitted around the outer periphery of the crankshaft 22. The second shaft seal 62 is used to seal between the first back pressure chamber 71 and the second back pressure chamber 72. The distal motor end of bracket 60 is mounted within the distal motor end of main bearing housing 50. The compressed high pressure gas in the compression chamber 408 is introduced into the two back pressure chambers, so that the pressure difference between the back pressure chamber and the suction chamber is borne by the two shaft seals respectively, the pressure difference borne by the shaft seals can be greatly reduced, the working conditions of the shaft seals are improved, and the service lives of the shaft seals are prolonged. Compared with the scroll compressor in the prior art, the utility model, applicable high-pressure refrigerant gas such as CO with high suction pressure and high exhaust pressure₂(carbon dioxide), and the like.

Preferably, the first shaft seal 52 and the second shaft seal 62 are identical in construction.

A first elastic retainer ring 56 is disposed in a motor end of the main bearing seat 50, and the first elastic retainer ring 56 is sleeved on the outer circumference of the crankshaft 22 and is located on a side of the first shaft seal 52 away from the motor 20 to limit the first shaft seal 52. A second elastic retainer ring 64 is arranged in the end of the bracket 60 close to the motor, and the second elastic retainer ring 64 is sleeved on the periphery of the crankshaft 22 and is positioned on one side of the second shaft seal 62 far away from the motor 20 to limit the second shaft seal 62.

Mounting locations may be provided in the motor-proximal end of main bearing housing 50 and in the motor-proximal end of bracket 60, respectively, to enable mounting of first seal 52 and first circlip 56, and second seal 62 and second circlip 64, respectively.

A third bearing 58 is disposed in the main bearing seat 50, and the third bearing 58 is sleeved on the outer periphery of the crankshaft 22 and located between the first circlip 56 and the bracket 60 to provide a rotational support for the crankshaft 22.

Further, a sealing ring 80 is provided between the outer wall of the bracket 60 at the distal motor end and the inner wall of the main bearing housing 50 at the distal motor end to seal the first back pressure chamber 71 and the second back pressure chamber 72.

Further, a gasket 90 is provided between the main bearing housing 50 and the orbiting and fixed

scrolls

40 and 30 to reduce noise and vibration generated by friction between the main bearing housing 50 and the orbiting and fixed scrolls 40. The spacer 90 has a through hole 94 through which the pin 100 passes.

In the present embodiment, as shown in fig. 8 and 9 in conjunction, the fixed scroll 30 includes an annulus 34 and a non-orbiting scroll portion 36 disposed within the annulus 34. The ring 34 is mounted to a mounting plate 38. The distal motor end of main bearing housing 50 is mounted to ring portion 34. The outer wall of the ring portion 34 is provided with the air inlet 302, and one end of the ring portion 34 close to the top cover 14 is provided with the air outlet 304.

In the present embodiment, as shown in fig. 10 and 11, the orbiting scroll 40 includes an end plate 42 and an orbiting scroll portion 44 provided at one end of the end plate 42. The orbiting scroll portion 44 meshes with the non-orbiting scroll portion 36 to form the compression chamber 408 described above. End plate 42 is adjacent main bearing housing 50 and main bearing housing 50 is connected to end plate 42 by a pin 100. One end of the back pressure passage 74 is located at an end of the orbiting scroll 44 near the compression chamber 408, and the other end is located at an end of the end plate 42 near the main bearing housing 50.

A hub 46 is formed at an end of the end plate 42 adjacent to the main bearing seat 50, and the hub 46 extends into the second back pressure chamber 72. The end of the back pressure passage 74 adjacent the compression chamber 408 is located inboard of the hub 46. An eccentric shaft 24 provided at the drive end of the crankshaft 22 is mounted in the hub 46 via a second bearing 26.

The above-mentioned embodiments only represent some embodiments of the present invention, and the description thereof is specific and detailed, but not to be construed as limiting the scope of the present invention. It should be noted that, for those skilled in the art, without departing from the spirit of the present invention, several variations and modifications can be made, which are within the scope of the present invention. Therefore, the protection scope of the present invention should be subject to the appended claims.

Claims

1. A scroll compressor comprises a machine shell, a controller installed at one end of the machine shell, a motor installed in the machine shell, a fixed scroll installed in the machine shell, a movable scroll, a main bearing seat and a support, wherein a suction cavity is formed in the machine shell, the movable scroll is arranged in the fixed scroll and meshed with the fixed scroll to form a compression cavity, the installation end of a crankshaft of the motor is installed in the controller, the driving end of the crankshaft penetrates through the main bearing seat and the support and is installed on the movable scroll, the main bearing seat is installed on the fixed scroll and connected with the movable scroll, the support is installed in the main bearing seat, a first back pressure cavity is formed between the main bearing seat and the support, a second back pressure cavity is formed between the support and the movable scroll, and the movable scroll is provided with back pressure channels respectively communicated with the compression cavity and the second back pressure cavity, its characterized in that, the bent axle is equipped with first oil return passageway and second oil return passageway, first oil return passageway respectively with second backpressure chamber and first backpressure chamber link to be used for will depositing in the refrigeration oil of second backpressure intracavity introduces first backpressure intracavity and carry out the throttle to the refrigeration oil and step down in order to provide the required pressure in first backpressure chamber, second oil return passageway respectively with first backpressure chamber and suction chamber intercommunication are used for with depositing in the refrigeration oil of first backpressure intracavity is introduced suction chamber and carry out the throttle to the refrigeration oil and step down in order to provide the refrigeration oil equal with the pressure of suction chamber.

2. The scroll compressor of claim 1, wherein the first and second oil return passages are located on either side of the crankshaft.

3. The scroll compressor of claim 1, wherein the first oil return passage comprises a first circuit disposed at the end of the driving end of the crankshaft and a second circuit disposed at the outer wall of the driving end of the crankshaft, the first circuit is communicated with the second back pressure cavity, the second circuit is communicated with the first back pressure cavity for throttling and depressurizing the refrigerant oil to provide the pressure required by the first back pressure cavity, and the first circuit and the second circuit are disposed vertically.

4. The scroll compressor of claim 3, wherein the first circuit extends in an axial direction of the crankshaft and the second circuit extends in a radial direction of the crankshaft, the second circuit being connected between ends of the first circuit.

5. The scroll compressor of claim 3, wherein the first circuit has an inner diameter of 4-5 mm and the second circuit has an inner diameter of 1.2-1.5 mm.

6. The scroll compressor of claim 1, wherein the second oil return passage comprises a third circuit disposed on an outer wall of a driving end of the crankshaft and a fourth circuit disposed on an end of a mounting end of the crankshaft, the third circuit being in communication with the first back pressure chamber for throttling and depressurizing the refrigerant oil to provide refrigerant oil having a pressure equal to a pressure in a suction chamber, the fourth circuit being in communication with the suction chamber, the third circuit and the fourth circuit being disposed vertically.

7. The scroll compressor of claim 6, wherein the third circuit extends in a radial direction of the crankshaft, the fourth circuit extends in an axial direction of the crankshaft, and an end of the third circuit distal from the first back pressure chamber is connected with an end of the fourth circuit distal from a mounting end of the crankshaft.

8. The scroll compressor of claim 6, wherein the third circuit has an inner diameter of 1-1.2 millimeters and the fourth circuit has an inner diameter of 4-5 millimeters.

9. The scroll compressor of claim 1, wherein a first shaft seal is disposed in a proximal motor end of the main bearing housing, the first shaft seal being sleeved to an outer circumference of the crankshaft, and a distal motor end of the main bearing housing being mounted to the fixed scroll and connected to the orbiting scroll by a pin.

10. The scroll compressor of claim 1, wherein a second shaft seal is provided in the near motor end of the bracket, the second shaft seal being provided to the outer circumference of the crankshaft, the far motor end of the bracket being mounted in the far motor end of the main bearing housing, a sealing ring being provided between the far motor end of the bracket and the far motor end of the main bearing housing.