JP2002070729A - Swash plate compressor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a swash plate compressor, in which a radial bearing supporting a drive shaft and a shaft sealing unit are lubricated well in a simple constitution. SOLUTION: A front housing comprises a suction chamber 19 and a discharging chamber 20, and a crank chamber 17 is formed between a cylinder block 13 and a rear housing 14. The drive shaft 18 is supported with a housing 11 in a rotary way via the first and second radial bearing 24 and 25, the drive shaft 18 coming through the suction chamber 19 and projecting out from the front housing 12. In the drive shaft 18, a connecting hole 60, consisting of the passage communicating with the suction chamber 19 and the crank chamber 17, is formed, wherein the position of the connecting hole entrance 60a is closer to the rear than that of the second radial bearing 25, and the position of the connecting hole exit 60b is closer to the rear than that of the first radial bearing 24. The rotation of the drive shaft 18 is transformed into the reciprocation of the piston 34 contained in a cylinder bore 33, via a lag plate 36 fixed to the drive shaft 18 to be able to rotate together and a hinge mechanism 39.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a swash plate type compressor having a single-headed piston for use in an air conditioner for a vehicle, for example, and more particularly to a radial supporting a drive shaft (rotary shaft) for driving the piston. The present invention relates to a swash plate type compressor having a lubricating configuration of a bearing and a shaft sealing device.

[0002]

2. Description of the Related Art Generally, a swash plate type compressor of this type generally has a configuration shown in FIG.
As shown in (1), the housing includes a front housing 71, a cylinder block 72, and a rear housing 73 which are joined and fixed to each other. The drive shaft 74 is rotatably supported by the housing via a pair of radial bearings 75 and 76 on the first end side and the second end side such that the first end protrudes from the front housing 71. Refrigerant gas is supplied to the housing closer to the first end of the drive shaft 74 than the first radial bearing 75.
A shaft sealing device 78 for preventing leakage from the air 7 to the atmosphere is provided.

In a compressor, lubrication of a sliding portion such as a bearing is performed by lubricating oil present in a mist state in a refrigerant gas. Therefore, lubrication becomes insufficient in a portion where the flow of the refrigerant gas is stagnant. In recent years, a compressor used in a refrigeration circuit for performing heat exchange including cooling a refrigerant in a supercritical region exceeding a critical temperature of the refrigerant, such as carbon dioxide (CO ₂ ), has been proposed in place of chlorofluorocarbon. . When such a refrigerant is used, the refrigerant pressure is one pressure lower than the pressure when using chlorofluorocarbon.
Since it becomes 0 times or more, and the load on the bearing and the shaft sealing device becomes large, it is particularly necessary to perform good lubrication.

Japanese Patent Application Laid-Open No. 11-241681 discloses FIG.
As shown in FIG. 7, a pressure reducing passage 79 is formed in the drive shaft 74. The inlet 79a of the pressure reducing passage 79 is connected to the shaft sealing device 7 on the first end side of the drive shaft 74 with respect to the first radial bearing 75.
8 is open at a position corresponding to the isolation chamber 80 in which the drive shaft 74 is accommodated.
The end is open at the end face. A fan 81 is fitted and fixed to the second end of the drive shaft 74. When the fan 81 rotates integrally with the drive shaft 74, the refrigerant in the pressure reducing passage 79 is pumped to the outlet 79b. The refrigerant pumped to the outlet 79b flows out of the radial bearing 76 into the crank chamber 77.

The isolation chamber 80 communicates with the crank chamber 77 via a gap in the radial bearing 75 and a gap in the thrust bearing 82. Radial bearing 7
The gap in 5 and the gap in thrust bearing 82 function as an oil supply passage.

In Japanese Patent Application Laid-Open No. Hei 8-165987, as shown in FIG. 7, a second end of a drive shaft 74 is opposed to a chamber 84 which is communicated with a suction chamber 83, and the drive shaft 74 has an inlet. A configuration is disclosed in which a communication passage 85 is formed in which the opening 85 a is opened at a position corresponding to the isolation chamber 80 in which the shaft sealing device 78 is housed, and the outlet 85 b is opened to communicate with the chamber 84.

[0007]

Problems to be Solved by the Invention
In the device disclosed in Japanese Patent Publication No. 81, a part of the refrigerant gas in the crank chamber 77 is introduced into the pressure reducing passage 79 through the gap of the first radial bearing 75 or the thrust bearing 82 by the action of the fan 81 provided on the drive shaft 74. And
After passing through the gap of the second radial bearing 76, the crank chamber 7
7 and the radial bearings 75, 7
6 and the lubrication of the shaft sealing device 78 are improved. However, the fan 81 for generating the flow in the pressure reducing passage 79 is required, and the structure becomes complicated.

On the other hand, in the configuration disclosed in Japanese Patent Application Laid-Open No. H8-165987, instead of providing a drive shaft 74 with a fan, a chamber 8 communicating the second end of the drive shaft 74 with the suction chamber 83 is provided.
4, a communication path 85 is formed in the drive shaft 74 to allow the isolation chamber 80 and the chamber 84 to communicate with each other. Therefore, in this configuration, the pressure in the crank chamber 77 and the pressure in the chamber
The refrigerant moves so as to pass through the gap between the radial bearings 75 and 76 or the thrust bearing 82 due to the pressure difference between the radial direction and the radial direction. However, the inlet 85a is connected to the first radial bearing 75.
And the position of the thrust bearing 82, the flow of the refrigerant gas passing through one of them becomes weak and lubrication becomes insufficient.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and has as its object to provide a swash plate type which can favorably lubricate a radial bearing for supporting a drive shaft and a shaft sealing device with a simple structure. An object of the present invention is to provide a compressor.

[0010]

In order to achieve the above object, according to the first aspect of the present invention, a housing having a suction chamber and a discharge chamber, a crank chamber partitioned and formed in the housing, First and second sides at the first end side and the second end side such that the ends protrude from the housing.
A drive shaft rotatably supported by the housing via a radial bearing, a single-headed piston reciprocally housed in a cylinder bore formed in the housing, and the drive shaft housed in the crank chamber; A swash plate type compressor having a cam plate operatively connected to the piston to convert the rotational motion of the piston into a reciprocating motion of the piston, wherein the housing supports a first end of the drive shaft. A suction pressure area for accommodating a shaft sealing device for the drive shaft is provided on the first end side of the first radial bearing, and a part of a path that connects the suction pressure area and the crank chamber is provided on the drive shaft. The communication hole is formed such that the entrance is located at the second end side of the second radial bearing and the exit is located at the second end side of the first radial bearing.

In the present invention, the rotational motion of the drive shaft is converted into the reciprocating motion of the piston via the cam plate, and the compression operation of the refrigerant gas is performed. In the suction pressure area accommodating the shaft sealing device of the drive shaft, refrigerant gas in the crank chamber is formed through a communication hole formed in the drive shaft based on a pressure difference between the pressure in the crank chamber and the pressure in the suction pressure area. Inflow. Since the flow of the refrigerant gas passes through the second radial bearing and the first radial bearing, lubrication of both radial bearings is performed well. In addition, since the refrigerant gas constantly flows into the suction pressure region, lubrication of the shaft sealing device housed in the suction pressure region is also favorably performed.

According to a second aspect of the present invention, in the first aspect of the invention, the suction chamber and the discharge chamber are provided on a protruding side of the drive shaft with respect to the crank chamber. It is located in the suction chamber.

In the present invention, a compression reaction force of the piston acts on the drive shaft via the cam plate, and a pressure of the crank chamber acts on the second end. And
The latter force acts in a direction opposite to the compression reaction force. Therefore, the power required to drive the drive shaft is greatly reduced as compared with the conventional compressor in which the directions of action of the two are the same. The shaft sealing device for sealing between the housing and the drive shaft protruding from the housing only needs to secure a sealing force that can withstand a pressure difference between the suction chamber and the outside air. Therefore, the life of the shaft sealing device can be extended and the reliability of the shaft seal can be increased, as compared with a conventional compressor that requires a sealing force that can withstand a pressure difference between the crank chamber having a higher pressure than the suction chamber and the outside air. improves.
This is particularly effective when the pressure in the crank chamber is significantly higher than that of the CFC refrigerant, such as when CO ₂ is used as the refrigerant. Further, the present invention is more effective in the case of a variable displacement type compressor in which the pressure in the crank chamber is higher than that of a fixed displacement type compressor having a fixed piston stroke.

According to a third aspect of the present invention, in the first or second aspect of the present invention, the cam plate is supported by the drive shaft so that the inclination angle can be changed, and the compressor is provided with the cam plate. Inclination control means for changing the inclination of the piston to change the stroke of the piston. Note that the tilt angle of the cam plate means an angle formed by a virtual plane orthogonal to the drive shaft and the cam plate.

In the present invention, the inclination angle of the cam plate is changed by the inclination control means to change the stroke of the piston. The tilt angle is changed such that the piston stroke becomes a value corresponding to the cooling load, and the compressor is operated with an appropriate displacement.

According to a fourth aspect of the present invention, in the third aspect of the invention, a throttle portion is provided in the communication hole in the middle. Therefore, in the present invention, the amount of the refrigerant gas discharged from the crank chamber to the suction chamber through the communication hole is adjusted by the throttle section, and the operation when changing the pressure in the crank chamber to change the inclination angle of the swash plate is performed. It is performed smoothly. Further, the processing is simplified as compared with a configuration in which the diameter of the entire communication hole is reduced.

According to the fifth aspect of the present invention, the first to fourth aspects of the present invention are provided.
In any one of the above, the shaft sealing device comprises a mechanical seal. The mechanical seal is excellent in pressure resistance, and exhibits a particularly effective sealing effect when the refrigerant pressure is significantly higher than that of the CFC refrigerant, for example, when CO ₂ is used as the refrigerant.

According to the sixth aspect of the present invention, the first to fourth aspects are provided.
In any one of the above, the shaft sealing device comprises a lip seal. The lip seal makes it possible to configure the shaft sealing device at low cost, and is excellent in oil sealability.

[0019]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS An embodiment in which the present invention is embodied in a variable displacement compressor of a vehicle air conditioner will be described below with reference to FIGS.

As shown in FIG. 1, a front housing 12, a cylinder block 13 and a rear housing 14 constituting a housing 11 of a compressor 10
Are arranged in order from the first end side (the left side in FIG. 1), and are joined and fixed to each other by a plurality of through bolts (only one is shown) 15. The valve / port forming body 16 is interposed between the front housing 12 and the cylinder block 13. The crank chamber 17 is partitioned into a region surrounded by the cylinder block 13 and the rear housing 14.

The drive shaft 18 passes through a hole formed in the valve / port forming body 16, and has a first end protruding from the front housing 12 and a second end disposed in the crank chamber 17. And is rotatably supported by the housing 11. A suction chamber 19 as a suction pressure area is formed in the front housing 12 at a position corresponding to a position near the first end of the drive shaft 18, and a substantially annular discharge chamber 20 is defined so as to surround the suction chamber 19. . An accommodation recess 21 is formed in the front housing 12 on the side of the suction chamber 19 facing the valve / port formation body 16. A shaft hole 22 is formed in the cylinder block 13 so as to communicate the crank chamber 17 and the suction chamber 19. An accommodation recess 23 is formed in the rear housing 14 on the side of the crank chamber 17.
The accommodation recess 23 forms a part of the crank chamber 17.

The drive shaft 18 passes through an insertion hole formed in the shaft hole 22, the suction chamber 19, the accommodation recess 21, and the front housing 12, and a first radial bearing having an intermediate portion disposed in the shaft hole 22. The second end portion is rotatably supported by the cylinder block 13 and the rear housing 14 via a second radial bearing 25 disposed in the housing recess 23 via 24.

A shaft sealing device 26 made of a mechanical seal is provided in the suction chamber 19. That is, FIG.
As shown in (a), the shaft sealing device 26 includes a ring 27 fitted and fixed in the housing recess 21 and an O (O)
A sliding ring 2 made of carbon, which is rotatably attached via a ring 28 and is in sliding contact with the ring 27.
9 is provided. The ring 27 is loosely inserted into the drive shaft 18, and an O-ring 30 is interposed between the ring 27 and the front housing 12. A groove 29 a is formed in the outer peripheral portion of the sliding ring 29. The shaft sealing device 26 includes a support ring 31 that can rotate integrally with the drive shaft 18. The support ring 31 includes a hook 31 a that engages with the groove 29 a and attaches the slide ring 29 to the ring 27. A spring 32 is provided as urging means. And the drive shaft 1
8 and the housing 11 are O-rings 28,
It is held by the contact between the sliding ring 29, the ring 27 and the O-ring 30.

A plurality of (only one is shown in the drawing) cylinder bores 33 are formed in the cylinder block 13 so as to surround the drive shaft 18 at equal angular intervals. That is,
The cylinder bore 33 is provided in the crank chamber 1 in the housing 11.
7 and between the valve / port forming body 16. The single-headed piston 34 is accommodated in each cylinder bore 33 so as to be able to reciprocate. The front and rear openings of the cylinder bore 33 are:
The compression chamber 35, which is closed by the valve / port forming body 16 and the piston 34, changes in volume in accordance with the reciprocation of the piston 34 in the cylinder bore 33.

The lug plate 36 as a rotary support is
The crankshaft 17 is fixed to the second end of the drive shaft 18 so as to be integrally rotatable. The lug plate 36 is in contact with the inner wall surface 14a of the rear housing 14 via the first thrust bearing 37. The inner wall surface 14a supports an axial load due to the compression reaction force of the piston 34, and functions as a regulating surface that regulates the axial position of the drive shaft 18.

The swash plate 38 as a cam plate is provided with the crankshaft 17 in a state where the drive shaft 18 is passed through the through hole 38a.
It is arranged in. The hinge mechanism 39 is interposed between the lug plate 36 and the swash plate 38. Hinge mechanism 3
Reference numeral 9 denotes a projection 2 provided from the front surface of the lug plate 36.
It is composed of two support arms 40 (only one is shown), guide holes 41 formed in each support arm 40, and two guide pins (only one is shown) fixed to the swash plate. I have. Each of the guide pins 42 has a spherical portion 42a at the tip thereof for engaging with the guide hole 41. And the swash plate 38
Is rotatable synchronously with the lug plate 36 and the drive shaft 18 by the hinge connection between the lug plate 36 via the hinge mechanism 39 and the support of the drive shaft 18.
8 along with the sliding movement in the axial direction of the drive shaft 18.
It is possible to tilt with respect to. The lug plate 36 and the hinge mechanism 39 constitute an inclination control means. The swash plate 3
8, a counter weight portion 38b is integrally formed on the opposite side of the hinge mechanism 39 with respect to the drive shaft 18.

The drive shaft 18 has a crank chamber 17 having a shaft hole 22.
A locking ring (for example, a circlip) 43 is fixed at a position corresponding to the larger diameter portion 22a. Large diameter part 22a
A second thrust bearing 44 is accommodated therein while being inserted through the drive shaft 18, and a first coil spring 45 as biasing means is provided on the drive shaft 18 between the locking ring 43 and the thrust bearing 44. It is wound. At least when the operation of the compressor 10 is stopped, the coil spring 45
8 is urged toward the regulation surface (inner wall surface 14a) that regulates the axial position of the drive shaft 18.

A second coil spring 46 as an inclination-reducing spring is wound around the drive shaft 18 between the lug plate 36 and the swash plate 38. The coil spring 46 urges the swash plate 38 in a direction approaching the cylinder block 13 (that is, a direction in which the inclination angle decreases).

Further, a third coil spring 47 as a return spring is provided on the drive shaft 18 between the swash plate 38 and the locking ring 43. When the swash plate 38 is in a state of large inclination (for example, at the position shown by the solid line in FIG. 1), the third coil spring 47 merely exists around the drive shaft 18 with its natural length, and the swash plate 38 Or any other member. On the other hand, as shown by the chain line in FIG.
The coil spring 47 is sandwiched between the swash plate 38 and the locking ring 43 and contracted, and the locking ring 43 is used as a support to separate the swash plate 38 from the cylinder block 13 in accordance with the degree of coil contraction. (Ie, in the direction of increasing the tilt angle).

The piston 34 is connected to the swash plate 3 via a shoe 48.
8 are moored at the periphery. Therefore, the rotational motion of the swash plate 38 accompanying the rotation of the drive shaft 18 is converted into the reciprocating motion of the piston 34 via the shoe 48. The swash plate 38 and the shoe 48 are both made of an iron-based metal, and a surface treatment for preventing seizure, for example, a treatment such as thermal spraying or friction welding of an aluminum-based metal is performed on a sliding contact portion of the swash plate 38 with the shoe 48. It has been subjected.

The drive shaft 18 is operatively connected to an engine 50 as a drive source via a power transmission mechanism 49. The power transmission mechanism 49 may be a clutch mechanism (for example, an electromagnetic clutch) capable of selecting transmission / disconnection of power by external electric control, or a constant transmission type clutchless without such a clutch mechanism. It may be a mechanism (for example, a belt / pulley combination). In the present embodiment, a clutchless type power transmission mechanism 49 is employed.

In the valve / port forming body 16, a suction port 51, a suction valve 52 for opening and closing the port 51, a discharge port 53, and a discharge valve 54 for opening and closing the port 53 are formed corresponding to each cylinder bore 33. ing. Suction port 51
The suction chamber 19 communicates with each of the cylinder bores 33 via the port, and the cylinder bore 33 communicates with the discharge chamber 20 via the discharge port 53.

The cylinder block 13 and the rear housing 14 are provided with an air supply passage 55 for communicating the crank chamber 17 and the discharge chamber 20, and a control valve 56 constituting tilt control means is provided in the air supply passage 55. Is provided. The outlet 55a of the air supply passage 55 is formed above the first thrust bearing 37. The control valve 56 is formed of a known electromagnetic valve, a valve chamber is formed on the air supply passage 55, the air supply passage 55 is opened by excitation of the solenoid, and the air supply passage 55 is closed by demagnetization of the solenoid. ing. Further, the opening can be adjusted by the magnitude of the exciting current of the solenoid.

The suction chamber 19 and the discharge chamber 20 are connected by an external refrigerant circuit 57. The external refrigerant circuit 57 and the variable displacement compressor having the above configuration constitute a refrigeration circuit of the vehicle air conditioner.

As shown in FIGS. 1 and 2 (b) and 2 (c), the drive shaft 18 is provided with a communication hole 60 which forms a part of a path connecting the suction chamber 19 and the crank chamber 17. I have. The communication hole 60 is formed such that the entrance 60 a is located on the second end side of the second radial bearing 25 and the exit 60 b is located on the second end side of the first radial bearing 24. A throttle 61 is provided in the middle of the communication hole 60. The throttle portion 61 is formed by fitting and fixing a separate member having a predetermined small-diameter hole in the communication hole 60.

A filter 62 is fixed to the second end of the drive shaft 18 at a portion where the entrance 60a of the communication hole 60 is opened so as to be integrally rotatable. The filter 62 is formed of, for example, a net, a plate having a large number of holes, or a porous plate. The communication hole 60 forms a bleed passage that connects the crank chamber 17 and the suction chamber 19.

In the shaft hole 22, between the outer peripheral surface of the drive shaft 18 and the inner surface of the cylinder block 13, a seal ring 63 as a seal member is provided on the second thrust bearing 44 side from the outlet 60b. Seal ring 63
Prevents the pressure in the crank chamber 17 from leaking into the suction chamber 19 through the shaft hole 22. The seal ring 63 is made of, for example, a rubber material or a fluororesin, and has a U-shaped cross section. Therefore, the crank chamber 17 and the suction chamber 19
Is a communication path only through the communication hole 60.

Next, the operation of the compressor configured as described above will be described. With the rotation of the drive shaft 18, the lug plate 36
And the swash plate 38 is integrally rotated via the hinge mechanism 39,
Rotational movement of the swash plate 38 causes each piston 3 to move through the shoe 48.
4 reciprocations. With the continuation of the driving, the suction, compression and discharge of the refrigerant are sequentially repeated in the compression chamber 35. The refrigerant supplied from the external refrigerant circuit 57 to the suction chamber 19 is sucked into the compression chamber 35 via the suction port 51, undergoes a compression action due to the movement of the piston 34, and then enters the discharge chamber 20 via the discharge port 53. Discharged. The refrigerant discharged into the discharge chamber 20 passes through the discharge passage to the external refrigerant circuit 5.
It is sent to 7.

The opening of the control valve 56, that is, the opening of the air supply passage 55, is adjusted by a control device (not shown) in accordance with the cooling load, and the communication between the discharge chamber 20 and the crank chamber 17 is changed. .

When the cooling load is large, the opening of the air supply passage 55 is reduced, and the flow rate of the refrigerant gas supplied from the discharge chamber 20 to the crank chamber 17 is reduced. When the amount of the refrigerant gas supplied to the crank chamber 17 decreases, the communication hole (bleed passage)
With the escape of the refrigerant gas to the suction chamber 19 via 60,
The pressure in the crank chamber 17 gradually decreases. As a result, the difference between the pressure in the crank chamber 17 and the pressure in the cylinder bore 33 via the piston 34 is reduced, and the swash plate 38 is displaced toward the maximum inclination angle. Therefore, the stroke amount of the piston 34 increases, and the discharge capacity increases.

Conversely, when the cooling load decreases, the control valve 5
6, the flow rate of the refrigerant gas supplied from the discharge chamber 20 to the crank chamber 17 increases. Crank chamber 17
When the amount of the refrigerant gas supplied to the suction chamber 19 exceeds the amount of refrigerant gas released to the suction chamber 19 through the communication hole 60, the pressure in the crank chamber 17 gradually increases. As a result, the piston 3 between the pressure in the crank chamber 17 and the pressure in the cylinder bore 33
Since the difference via 4 becomes large, the swash plate 38 is displaced to the minimum inclination angle side. Therefore, the stroke amount of the piston 34 is reduced, and the discharge capacity is reduced.

When the piston 34 performs the compression operation of the refrigerant gas, the compression reaction force F1 of the piston 34 acts on the drive shaft 18 toward the rear housing 14 via the shoe 48, the hinge mechanism 39 and the lug plate 36. I do. Also,
The pressure Pc of the crank chamber 17 acts on the second end of the drive shaft 18 in a direction opposite to the compression reaction force F1, and the first end of the drive shaft 18 has an external pressure (high pressure) in an atmosphere lower than the pressure Pc of the crank chamber 17. The pressure Pa) acts in the same direction as the compression reaction force F1. That is, the difference between the pressure Pc of the crank chamber 17 and the external pressure (atmospheric pressure Pa) is applied to the drive shaft 18 in the crank chamber 17.
F2 = (Pc−Pa) · S obtained by multiplying the cross-sectional area S of the portion corresponding to the seal ring 63 by the compression reaction force F1
Acts on the drive shaft 18 in the opposite direction. Conventionally, the compression reaction force F
1 and the force F2 act in the same direction, whereas in the present invention, the latter force F2 acts in a direction opposite to the compression reaction force F1. Therefore, the power for driving the drive shaft 18 is reduced.

In the case of the clutchless type, the rotation of the engine 50 is transmitted to the drive shaft 18 even when the operation of the air conditioner is stopped. At this time, the inclination angle of the swash plate 38 is kept to a minimum, but the compression operation of the piston 34 is performed (compressor off operation), and a compression reaction force F1 acts on the drive shaft 18. However, as described above, the force F2 based on the differential pressure between the crank pressure Pc and the atmospheric pressure Pa is applied to the drive shaft 18 by the compression reaction force F.
1 acts in the direction of canceling, so that the power consumption of the compressor 10 during the off operation is reduced.

When the operation of the compressor 10 is stopped, that is, when the piston 3
When the compression reaction force F1 of No. 4 does not act on the drive shaft 18, there is no force for urging the drive shaft 18 toward the regulating surface.
Since the pressure in the housing 11 is higher than the pressure Pa of the outside air, in a state where there is no force for urging the drive shaft 18 toward the regulating surface, the drive shaft 18 moves away from the first end side, that is, in a direction away from the rear housing 14. The lug plate 36 is moved away from the thrust bearing 37. However, in this embodiment, since the first coil spring 45 constantly urges the drive shaft 18 toward the rear housing 14, the lug plate 36 keeps the thrust bearing 3 even when the operation of the compressor 10 is stopped.
7 is held.

The crank chamber 17 and the suction chamber 19 are connected to the drive shaft 1.
8 through a communication hole 60 formed in the communication hole 6.
A seal ring 63 is provided on the side of the crank chamber 17 from the outlet 60b. Therefore, the path that connects the crank chamber 17 and the suction chamber 19 includes a gap between the first thrust bearing 37, a gap between the lug plate 36 and the inner wall surface 14a of the rear housing 14, a gap between the second radial bearing 25, and a housing recess. 23, the communication hole 60 and the first radial bearing 24 only pass through the gap. As a result, the flow of the refrigerant gas that moves from the crank chamber 17 to the suction chamber 19 based on the pressure difference between the pressure Pc of the crank chamber 17 and the pressure Ps of the suction chamber 19 flows through the first thrust bearing 37 and the second radial bearing. 25 and the first radial bearing 24, and each bearing 37, 25, 24 is reliably lubricated by the lubricating oil in the refrigerant gas.

The suction chamber 1 in which the shaft sealing device 26 is housed
Since the refrigerant gas constantly flows into the shaft 9, the lubrication of the shaft sealing device 26 is also performed well. This embodiment has the following effects.

(1) The housing 11 is provided with a suction pressure area for accommodating the shaft sealing device 26 of the drive shaft 18 on the first end side of the first radial bearing 24 supporting the first end side of the drive shaft 18. The drive shaft 18 has a communication hole 6 which forms a part of a path for communicating the suction pressure region with the crank chamber 17.
0, the inlet 60a is located on the second end side of the second radial bearing 25, and the outlet 60b is located on the first radial bearing 24.
It is formed so as to be located closer to the second end. Therefore, the flow of the refrigerant gas from the crank chamber 17 to the suction pressure region surely passes through the two radial bearings 24, 25, and the lubricating oil contained in the refrigerant gas effectively lubricates the two radial bearings 24, 25. Will be Further, the ambient temperature of the shaft sealing device 26 is lowered by the suctioned refrigerant gas as compared with the conventional configuration, and the durability is improved.

(2) Since the suction chamber 19 constitutes the suction pressure region, there is no need to separately arrange the suction pressure region, and the structure is simplified. (3) A seal ring 63 is provided on the crank chamber 17 side (the second end side of the drive shaft 18) from the outlet 60b of the communication hole 60, and the flow path of the refrigerant gas from the crank chamber 17 to the suction pressure region is the There is only a path passing through one thrust bearing 37 and both radial bearings 24, 25, and the lubrication of each bearing 24, 25, 37 is performed better. Further, since the refrigerant gas in the crank chamber 17 is bled into the suction chamber 19 only from the communication hole 60 functioning as a bleed passage, the pressure in the crank chamber 17 can be accurately adjusted when changing the discharge capacity. Become.

(4) The suction chamber 19 and the discharge chamber 20 are provided on the protruding side of the drive shaft 18 with respect to the crank chamber 17, and the shaft sealing device 26 is disposed in the suction chamber 19. Therefore,
The life of the shaft sealing device 26 can be extended and the reliability of the shaft seal can be extended as compared with a conventional compressor that requires a sealing force to withstand a differential pressure between the crank chamber 17 having a higher pressure than the suction chamber 19 and the outside air. Is improved. Further, a force F2 proportional to the pressure difference between the pressure Pc of the crank chamber 17 and the outside air (atmosphere) Pa acts on the drive shaft 18 in a direction opposite to the compression reaction force F1 acting on the drive shaft 18. Therefore, both F1, F2
The power for driving the drive shaft 18 can be greatly reduced as compared with the conventional compressor in which the action direction of the drive shaft 18 is the same. Further, the durability of the thrust bearing 37 is improved. These effects are particularly effective when the pressure in the crank chamber 17 is significantly higher than that of the refrigerant, such as when CO ₂ is used as the refrigerant. This is more effective in the case of a variable displacement type compressor in which the pressure in the crank chamber 17 is higher than that of a fixed displacement type compressor in which the stroke of the piston 34 is constant.

(5) Communication hole 6 formed in drive shaft 18
0 serves as a bleed passage, and a throttle 61 is formed in the communication hole 60. When using CO ₂ as a refrigerant, the pressure in the crank chamber 17 becomes high, the amount of air extracted into the suction chamber 19 changes greatly due to a slight difference in the diameter of the air extraction passage, and it becomes difficult to accurately control the capacity. . When the communication hole 60 as a bleed passage is formed with a constant diameter, it is difficult to process,
The processing is simplified by inserting and providing the drawing portion 61 in the middle.

(6) An air supply passage 55 communicating the discharge chamber 20 and the crank chamber 17 is provided, and the opening degree of the air supply passage 55 is changed by a control valve 56 provided in the middle of the air supply passage 55. To adjust the pressure in the crank chamber 17. Therefore, the pressure in the crank chamber 17 can be easily adjusted by adjusting the opening of the control valve 56.

(7) The shaft sealing device 26 is formed of a mechanical seal, and the mechanical seal has excellent pressure resistance. Therefore, when the pressure in the crank chamber 17 is significantly higher than that of the CFC refrigerant, as in the case of using CO ₂ as the refrigerant, a particularly effective sealing effect is achieved. This is more effective in the case of a variable displacement type compressor in which the pressure in the crank chamber 17 is higher than that of a fixed displacement type compressor in which the stroke of the piston 34 is constant.

The embodiment is not limited to the above, and may be configured, for example, as follows. The shaft sealing device 26 does not necessarily need to be disposed in the suction chamber 19, and a chamber 64 as a suction pressure area in which the shaft sealing device 26 is housed is provided inside the annular suction chamber 19 as shown in FIG. A configuration may be made in which the suction chamber 19 and the chamber 64 communicate with each other through the hole 65a. Also in this case, the effects (1), (3) to (7) of the above embodiment are obtained.

When the suction pressure area for accommodating the shaft sealing device 26 is independent of the suction chamber 19, the suction chamber 19 may be arranged outside the discharge chamber 20. As shown in FIG. 4, the suction chamber 19 and the discharge chamber 20 may be applied to the rear housing 14, that is, to the compressor 10 configured to be provided on the side opposite to the projecting side of the drive shaft 18. The chamber 64 serving as the suction pressure area communicates with the suction chamber 19 through a passage (not shown). The passage may be either an external pipe or a passage formed in the wall of the housing.

The bleed passage 60 may be formed to have a constant diameter without the throttle 61 of the bleed passage 60. But,
The processing is simplified by providing the drawing portion 61. ○ The compressor is not limited to the variable capacity type, but may be a fixed capacity type compressor.

The cam plate (swash plate 38) is the drive shaft 1
Instead of the configuration in which the cam plate rotates integrally with the drive shaft 8, the present invention may be applied to a wobble type compressor in which a cam plate is supported so as to be rotatable relative to a drive shaft and swings.

The shaft sealing device is not limited to the mechanical seal 26, and a lip seal whose sliding surface is the peripheral surface of the drive shaft 18 may be used. The lip seal has an advantage that the shaft sealing device can be configured at a low cost and has excellent oil sealing properties. In particular, the lip seal 67 shown in FIG.
A lip ring 67b made of a resin such as a fluororesin and a lip ring 67c made of a rubber are held in the main body fitting 67a. Provision of the plurality of lip rings 67b and 67c enhances shaft sealing performance. A helical groove 67d centering on the axis of the drive shaft 18 is formed in the sliding surface of the lip ring 67b with the drive shaft 18. Spiral groove 6
7d has an oil return action of guiding lubricating oil to the suction chamber 19 side by relative rotation with the drive shaft 18, and further improves the oil sealing property of the lip seal 67.

A control valve 56 for adjusting the opening of the control passage
Are not limited to the electromagnetic control valve.
As in the case of a control valve disclosed in Japanese Patent Publication No. 81, even a so-called internal control valve having a diaphragm that detects and changes the suction pressure and a valve mechanism that controls the opening of the control passage by the displacement of the diaphragm. Good. However, in a clutchless type compressor, an electromagnetic valve that can be controlled from the outside is preferable.

The drive source is not limited to the engine 50 but may be an electric motor. In this case, it can be installed in an electric vehicle. The technical idea grasped from each of the embodiments will be described.

(1) In the invention according to any one of the first to sixth aspects, a seal member is provided on a second end side of the drive shaft from an outlet of the communication hole. In this case, the flow of the refrigerant gas from the crank chamber to the suction pressure region in which the shaft sealing device is accommodated through the communication hole becomes smooth,
Good lubrication of both radial bearings.

(2) In the invention according to claim 6,
The shaft sealing device (lip seal) includes a plurality of lip rings. (3) In the invention according to any one of (6) and (2), the lip ring of the shaft sealing device (lip seal) returns oil into the housing by relative rotation with a drive shaft. Is formed.

[0062]

As described above in detail, according to the first to sixth aspects of the present invention, the lubrication of the radial bearing for supporting the drive shaft and the shaft sealing device can be favorably performed with a simple structure. it can.

[Brief description of the drawings]

FIG. 1 is a sectional view of a compressor according to an embodiment.

2A is a partial sectional view of a shaft sealing device, FIG. 2B is a partial enlarged sectional view near an outlet of a communication hole, and FIG. 2C is a partial enlarged sectional view near a second end of a drive shaft.

FIG. 3 is a partial cross-sectional view of another embodiment.

FIG. 4 is a sectional view of a variable displacement compressor according to another embodiment.

FIG. 5 is a partial cross-sectional view of a shaft sealing device according to another embodiment.

FIG. 6 is a sectional view of a conventional variable displacement compressor.

FIG. 7 is a cross-sectional view of another prior art variable displacement compressor.

[Explanation of symbols]

10 compressor, 11 housing, 17 crankcase,
18: drive shaft, 19: suction chamber as suction pressure area, 20
... discharge chamber, 24 ... first radial bearing, 25 ... second
Radial bearing, 26: shaft sealing device, 33: cylinder bore, 34: piston, 36: lug plate as a rotary support, 38: swash plate as a cam plate, 39: hinge mechanism constituting tilt angle control means, 56 ... Control valve, 60: communication hole, 60a: inlet, 60b: outlet, 61
... throttle section, 64 ... chamber as suction pressure area.

 ──────────────────────────────────────────────────続 き Continuing on the front page (72) Inventor Masakazu Murase 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Junya Suzuki 2-1-1 Toyota-cho, Kariya-shi, Aichi Prefecture Stock Inside Toyota Industries Corporation (72) Inventor Tatsuya Koide 2-1-1 Toyotamachi, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Takayuki Imai 2-1-1 Toyotamachi, Kariya City, Aichi Prefecture Inside Toyota Industries Corporation (72) Inventor Toshiro Fujii 2-1-1 Toyota-cho, Kariya-shi, Aichi F-term inside Toyota Industries Corporation (Reference) 3H076 AA06 BB17 CC12 CC20 CC36 CC72

Claims (6)

[Claims] A housing including a suction chamber and a discharge chamber; a crank chamber defined in the housing; a first end and a second end such that a first end protrudes from the housing. A drive shaft rotatably supported by the housing via first and second radial bearings on a side, a single-headed piston reciprocally housed in a cylinder bore formed in the housing, and the crank chamber A swash plate compressor having a cam plate operatively connected to the piston to convert a rotational motion of the drive shaft into a reciprocating motion of the piston. A suction pressure area for accommodating a shaft sealing device for the drive shaft is provided on the first end side of the first radial bearing supporting the one end side, and the suction pressure area is provided on the drive shaft. A communication hole that forms a part of a path that communicates with the crank chamber has an inlet located at a second end side of the second radial bearing and an outlet located at a second end side of the first radial bearing. Swash plate type compressor formed as follows. 2. The swash plate type compression according to claim 1, wherein the suction chamber and the discharge chamber are provided on a protruding side of the drive shaft with respect to the crank chamber, and the shaft sealing device is disposed in the suction chamber. Machine. 3. The cam plate is supported on the drive shaft such that the tilt angle can be changed, and the compressor includes tilt angle control means for changing the tilt angle of the cam plate to change the stroke of the piston. The swash plate type compressor according to claim 1 or 2. 4. The swash plate compressor according to claim 3, wherein a throttle portion is provided in the communication hole in the middle. 5. The swash plate type compressor according to claim 1, wherein said shaft sealing device comprises a mechanical seal. 6. The swash plate type compressor according to claim 1, wherein said shaft sealing device comprises a lip seal.