WO2002055880A1

WO2002055880A1 - Swash plate compressor

Info

Publication number: WO2002055880A1
Application number: PCT/JP2001/011304
Authority: WO
Inventors: Takeshi Yamada; Naoya Yokomachi; Masakazu Murase; Toshiro Fujii; Junya Suzuki; Tatsuya Koide; Takayuki Imai; Kiyoshi Yagi
Original assignee: Kabushiki Kaisha Toyota Jidoshokki
Priority date: 2001-01-15
Filing date: 2001-12-21
Publication date: 2002-07-18
Also published as: CN1429317A

Abstract

In a swash plate compressor, a shaft seal device (26) for sealing a clearance between a drive shaft (18) and a housing is received in a suction chamber (19). The drive shaft (18) is supported at the first end thereof by a first radial bearing (24) and at the second end thereof by a second radial bearing (25). The suction chamber (19) is disposed closer to the first end of the drive shaft than the first radial bearing (24). The drive shaft (18) is formed with a communication hole (60), which provides communication between the suction chamber (19) and a crank chamber (17). The inlet (60a) of the communication hole is positioned closer to the second end than the second radial bearing (25), and the outlet (60b) is positioned closer to the second end than the first radial bearing (24).

Description

Specification

Swash plate compressor

Technical field

The present invention relates to, for example, a swash plate type compressor having a single-headed piston used for an air conditioner of a vehicle or the like, and more particularly to a radial bearing and a shaft sealing device for supporting a drive shaft for driving a biston. The present invention relates to improvement of a lubrication structure. Background art

In this type of swash plate compressor, as shown in FIG. 6, the housing is generally composed of a front housing 71, a cylinder block 72 and a rear housing 73 which are fixedly connected to each other. The drive shaft 74 is rotatable with respect to the housing via a pair of radial bearings 75, 76 at the first end and the second end so that the first end projects forward from the front housing 71. Supported. A shaft sealing device 78 for preventing refrigerant gas from leaking from the crank chamber 77 to the atmosphere is disposed closer to the first end of the drive shaft 74 than the first radial bearing 75 in the housing. In a compressor, lubrication of sliding parts such as bearings is performed by lubricating oil that exists in a mist state in the refrigerant gas. Therefore, lubrication becomes insufficient in the portion where the flow of the refrigerant gas is stagnant. In recent years, a compressor using carbon dioxide (co ₂ ) in a refrigeration circuit instead of chlorofluorocarbon has been proposed. When such a refrigerant is used, the pressure of the refrigerant is at least 10 times higher than the pressure when fluorocarbon is used, and the load on the bearings and shaft sealing device is increased. There is. In the compressor described in Japanese Unexamined Patent Application Publication No. Hei. 1—2 4] 681, as shown in FIG. 6, the shaft sealing device 78 has an isolation chamber 80 formed forward of the first radial bearing 75. It is contained in The drive shaft 74 has a pressure reducing passage 79 formed therein. The entrance 79 a of the decompression passage 79 opens toward the isolation chamber 80, and the exit 79 b of the decompression passage 79 is The drive shaft 74 is open at the end face of the second end. 'A fan 81 is 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 799b side flows out of the radial bearing 76 into the crankcase 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. The gap in the radial bearing 75 and the gap in the thrust bearing 82 function as an oil supply passage. Further, in another compressor described in Japanese Patent Application Laid-Open No. H08-165,897, as shown in FIG. 7, a chamber 8 in which a second end of a drive shaft 74 communicates with a suction chamber 83 is provided. 4 facing. A communication passage 85 is formed in the drive shaft 74. The entrance 85 a of the communication passage 85 opens toward the isolation chamber 80, and the outlet 85 b opens to communicate with the chamber 84. In the conventional apparatus disclosed in FIG. 6, a part of the refrigerant gas in the crank chamber 77 is made to flow by the action of the fan 81 provided on the drive shaft 74 or the first radial bearing 75 or the thruster. It is introduced into the pressure reducing passageway 79 through the gap between the bearings 82 and returns to the crank chamber 77 through the gap between the second radial bearing 76. Therefore, both radial bearings.

Lubrication of 75, 76 and shaft sealing device 78 will be improved. However, the fan 81 is required to generate the flow of the lubricating oil in the pressure reducing passage 79, which complicates the structure.

On the other hand, in the conventional configuration disclosed in FIG. 7, instead of providing a fan on the drive shaft 74, the second end of the drive shaft 74 is disposed in the chamber 84, and the isolation chamber 8 is provided on the drive shaft 74. A communication passage 85 that connects the chamber 0 and the chamber 84 is formed. Therefore, the pressure in the crankcase 7 7 and the chamber

The refrigerant moves through the gap between the radial bearings 75 and 76 or the thrust bearing 82 based on the pressure difference between the refrigerant and the thrust bearing 82. However, since the inlet 85 a is located between the first radial bearing 75 and the thrust bearing 82, either The flow of the refrigerant gas passing through one side is weakened, resulting in insufficient lubrication. The present invention has been made in view of the above problems, and an object of the present invention is to provide a swash plate compressor that can favorably lubricate a radial bearing that supports a drive shaft and a shaft sealing device with a simple configuration. To provide. Disclosure of the invention

According to the present invention, there is provided a swash plate compressor having the following configuration. The swash plate compressor has a housing having a suction chamber, a discharge chamber, and a crank chamber. The housing has at least one cylinder bore. A drive shaft is rotatably supported by the housing. The drive shaft has a first end and a second end, and the first end is supported so as to protrude from the housing. The first and second ends of the drive shaft are supported by first and second radial bearings, respectively. The piston is reciprocally housed in each cylinder bore. A cam plate is housed in the crank chamber and is operatively connected to the piston for converting the rotational motion of the drive shaft into the reciprocating motion of the piston. The shaft sealing device seals between the drive shaft and the housing. The shaft sealing device is accommodated in the suction chamber, and the suction chamber is also disposed on the first end side of the drive shaft with the first radial bearing. The drive shaft has a communication hole for communicating the suction chamber and the crank chamber. The communication hole has an inlet and an outlet, and the inlet is located on the second end side of the second radial bearing, and the outlet is located on the second end side of the first radial bearing. BRIEF DESCRIPTION OF THE FIGURES

FIG. 1 is a cross-sectional view of the compressor according to the first embodiment.

Fig. 2 (a) is a partial cross-sectional view of the shaft seal device of the compressor in Fig. 1, Fig. 2 (b) is a partially enlarged cross-sectional view near the outlet of the communication hole, and Fig. 2 (c) is the second end of the drive shaft. FIG. FIG. 3 is a partial cross-sectional view of the compressor according to the second embodiment.

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

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

Fig. 6 is a cross-sectional view of a conventional variable displacement compressor.

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

FIG. 8 is a sectional view showing a compressor according to a fifth embodiment. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, a first embodiment in which the present invention is embodied in a variable displacement compressor of a vehicle air conditioner will be described with reference to FIGS. As shown in FIG. 1, the front housing 12, the cylinder block 13, and the rear housing 14, which constitute the housing 11 of the compressor 10, are connected to the first end of the housing 11 (the left side of FIG. 1). ) And are fixed to each other by a plurality of through bolts (only one is shown) 15. The valve plate 16 is interposed between the front housing 12 and the cylinder block 13. The crank chamber 17 is partitioned between the cylinder block 13 and the rear housing 14. The drive shaft 18 penetrates a hole formed in the valve plate 16, the first end of which protrudes from the front housing 12, and the second end of which is disposed in the crank chamber 17. It is rotatably supported on 1 1. Near the first end of the drive shaft 18, a suction chamber 19 as a suction pressure area is formed in the front housing 12, and a substantially annular discharge chamber 20 is formed so as to surround the suction chamber 19. Is formed. The front housing 12 has a receiving recess 21 facing the pulp plate 16 of the suction chamber 19. A shaft hole 22 is formed in the cylinder block 13 so that the crank chamber 17 and the suction chamber 19 communicate with each other. A housing recess 23 is formed in the rear housing 14 and opens toward the crank chamber 17. The housing recess 23 forms a part of the crank chamber 17. The drive shaft 18 penetrates through the shaft hole 22, the suction chamber 19, the accommodation recess 21, and the insertion hole formed in the front nosing 12. In this state, the intermediate portion of the drive shaft 18 is rotatably supported by the cylinder block 13 by the first radial bearing 24 disposed in the shaft hole 22, and the second end of the drive shaft is housed therein. The second radial bearing 25 disposed in the concave portion 23 rotatably supports the rear housing 14. In the suction chamber 19, a shaft sealing device 26 'composed of a mechanical seal is provided. That is, as shown in FIG. 2 (a), the shaft sealing device 26 includes a fixing ring 27 fitted and fixed in the housing recess 21, and a 0 (o) ring 28 on the drive shaft 18. And a sliding ring 29 made of carbon that slides on the fixing ring 27. The fixed ring 27 is loosely inserted into the drive shaft 18, and an O-ring 30 is interposed between the fixed ring 27 and the front housing 12. A groove 29 a extending in the axial direction is formed in the outer peripheral portion of the sliding ring 29. Further, the shaft sealing device 26 includes a support ring 31 that can rotate integrally with the drive shaft 18. The support ring 31 has a locking piece 31a that engages with the groove 29a and a panel 32 that urges the sliding ring 29 toward the fixed ring 27 side. Then, the seal between the drive shaft 18 and the housing 11 is held by the contact between the O-ring 28, the sliding ring 29, the fixed 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 formed between the crank chamber 17 in the housing 11 and the valve plate 16. The single-headed piston 34 is reciprocally accommodated in each cylinder bore 33. The front and rear openings of the cylinder bore 33 are closed by a valve plate 16 and a piston 34, and a piston 34 is provided in the cylinder bore 33. A compression chamber 35 whose volume changes according to the reciprocating motion is defined. A lug plate 36 as a rotary support is fixed to the crank chamber 17 near 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 the 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 1-8. The swash plate 38 as a cam plate has a through hole 38a, and is disposed in the crank chamber 17 with the drive shaft 18 penetrating the through hole 38a. Hinge mechanism 3

9 is interposed between the lug plate 36 and the swash plate 38. The hinge mechanism 39 includes two support arms 40 (only one is shown) protruding from the front surface of the lug plate 36, a guide hole 41 formed in each support arm 40, It consists of two guide bins (only one is shown) fixed to the plate 38. Guide bins

42 has a spherical portion 42a at the tip for engaging with the guide hole 41. And the swashplate

The drive shaft 18 can rotate synchronously with the lug plate 36 and the drive shaft 18 via the hinge mechanism 39, and can tilt with respect to the drive shaft 18 while sliding in the axial direction of the drive shaft 18. It is possible. The lug plate 36 and the hinge mechanism 39 constitute tilt control means. The swash plate 38 is formed with a power weight part 38 b on the opposite side of the hinge mechanism 39 with respect to the drive shaft 18. A lock ring (for example, a circuit) 43 is fixed to the drive shaft 18, and the lock ring 43 is disposed in the large-diameter portion 22 a of the shaft hole 22. The second thrust bearing 44 is accommodated in the large diameter portion 22 a while being inserted through the drive shaft 18, and between the locking ring 43 and the thrust bearing 44 on the drive shaft 18. The first coil spring 45 is wound on the first coil spring. At least when the compressor 10 is stopped, the first coil spring 45 moves the drive shaft 18 to the regulating surface (the inner wall surface 14 of the rear housing 14). a) Bias toward. A second coil spring 46 is wound on the drive shaft 18 between the lug plate 36 and the swash plate 38. The second coil panel 46 urges the swash plate 38 in a direction to approach the cylinder block 13, that is, in a direction to decrease the tilt angle. A third coil spring 47 as a return panel is provided on the drive shaft 18 between the swash plate 38 and the locking ring 43. When the swash plate 38 is in the state of large inclination (for example, at the position shown by the solid line in FIG. 1), the third coil panel 47 simply exists around the drive shaft 18 with its natural length. It does not exert any biasing action on the swash plate 38 or other members. On the other hand, as shown by the chain line in FIG. 1, when the swash plate 38 shifts to the small angle state, the third coil spring 47 contracts between the swash plate 38 and the locking ring 43 and contracts. According to the degree of contraction, the swash plate 38 is urged in a direction away from the cylinder block 13 (that is, in a direction to increase the tilt angle). The piston 34 is moored to the periphery of the swash plate 38 via a shoe 48. Therefore, the rotational motion of the swash plate 38 accompanying the rotation of the drive shaft 18 is converted to the reciprocating motion of the piston 34 via the shoe 48. The swash plate 38 and the shroud 48 are both made of iron-based metal, and the sliding contact between the swash plate 38 and the shroud 48 is subjected to surface treatment to prevent seizure, such as thermal spraying or friction of aluminum-based metal. Processing such as pressure welding is performed. The drive shaft 18 is operatively connected to the engine 50 via a power transmission mechanism 49. The power transmission mechanism 49 may be a clutch mechanism (for example, an electromagnetic clutch) capable of selecting power transmission interruption by external electric control, or a constant transmission type that does not have such a clutch mechanism. A clutchless mechanism (for example, a combination of a belt Z pulley) may be used. In this embodiment, a clutchless type power transmission mechanism 49 is employed. The valve plate 16 corresponds to each cylinder bore 33 and has a suction port 51, a suction valve 52 for opening and closing the port 51, a discharge port 53, and a discharge valve 5 for opening and closing the port 53. 4 are formed. The suction chamber 19 communicates with each of the cylinder bores 33 via the suction port 51, 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.In the middle of the air supply passage 55, the inclination angle of the swash plate is set. A control valve 56 for controlling is provided. The outlet 55 a of the air supply passage 55 is formed above the first thrust bearing 37. The control valve 56 is formed of a known solenoid 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 formed by demagnetization of the solenoid. Is blocked. Also, the opening can be adjusted depending on the magnitude of the excitation 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 compressor constitute a refrigeration circuit of the vehicle air conditioner. As shown in FIGS. 1 and 2 (b) and (c), the drive shaft 18 is provided with a communication hole 60 that forms a part of a bleed passage that connects the suction chamber 19 and the crank chamber 17. Is formed. The communication hole 60 has an inlet 60 a located on the second end side of the second radial bearing 25 and an outlet 60 b located on the second end side of the first radial bearing 24. A throttle portion 61 is provided in the middle of the formed 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. At the second end of the drive shaft 18, a filter 62 is fixed to the opening of the entrance 60 a of the communication hole 60 so as to be rotatable. The filter 62 is formed of, for example, a net, a plate in which a number of holes are formed, or a porous plate. A seal is provided between the outlet 60b and the second thrust bearing 44 so as to be located between the outer peripheral surface of the drive shaft 18 and the inner surface of the cylinder block 13 in the shaft hole 22. Ring 63 is provided. The seal ring 63 prevents the pressure in the crank chamber 17 from leaking into the suction chamber 19 via the shaft hole 22. The seal ring 63 is made of, for example, a rubber material-fluorine resin, and has a U-shaped cross section. Next, the operation of the compressor configured as described above will be described.

With the rotation of the drive shaft 18, the swash plate 38 is integrally rotated via the lug plate 36 and the hinge mechanism 39, and the rotational motion of the swash plate 38 causes the movement of each piston 3 4 Converted to reciprocating motion. Thus, in the compression chamber 35, the suction, compression, and discharge of the refrigerant are sequentially repeated. The refrigerant supplied from the external refrigerant circuit 57 to the suction chamber 19 is sucked into the compression chamber 35 through the suction boat 51 and subjected to the compression action by the movement of the piston 34, and then to the discharge port 53. Through the discharge chamber 20. The refrigerant discharged into the discharge chamber 20 is sent to the external refrigerant circuit 57 via a discharge passage. Then, 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) according to the cooling load, and the communication state between the discharge chamber 20 and the crank chamber 17 is changed. Is done. 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 pressure of the crank chamber ¹⁷ gradually decreases due to the escape of the refrigerant gas to the suction chamber 19 via the communication hole (bleed passage) 60. as a result, Since the difference between the pressure in the crank chamber 17 and the pressure in the cylinder bore 33 through the piston 4 becomes smaller, the swash plate 38 is displaced toward the maximum inclination angle. Therefore, the stroke amount of the piston 34 increases, and the displacement of the compressor increases. Conversely, when the cooling load decreases, the opening of the control valve 56 increases, and the flow rate of the refrigerant gas supplied from the discharge chamber 20 to the crank chamber 17 increases. When the amount of refrigerant gas supplied to the crank chamber 17 exceeds the amount of refrigerant gas leaked to the suction chamber 19 through the communication hole 60, the pressure in the crank chamber 17 gradually increases. . As a result, the difference between the pressure in the crank chamber 17 and the pressure in the cylinder bore 33 via the pistons 34 increases, so that the swash plate 38 is displaced to the minimum inclination angle side. Accordingly, the stroke amount of the piston 34 is reduced, and the discharge capacity of the compressor is reduced. When the piston 34 performs the compression operation of the refrigerant gas, the compression reaction force F 1 (not shown) of the biston 34 is applied to the drive shaft 18 by the shower 48, the hinge mechanism 39 and the lug plate 36, Acts toward the lya housing 14 side. At the second end of the drive shaft 18, the pressure P c (not shown) of the crank chamber 17 acts in the opposite direction to the compression reaction force F 1, and at the first end, the crank chamber 17 Atmospheric pressure Pa (not shown) lower than pressure Pc acts in the same direction as the compression reaction force F1. That is, the cross-sectional area S (not shown) of the portion corresponding to the seal ring 63 of the drive shaft 18 in the crank chamber 17 is determined by the differential pressure between the pressure P c of the crank chamber 17 and the atmospheric pressure Pa. The multiplied force F 2 = (P c -P a) · S acts on the drive shaft 18 in a direction opposite to the compression reaction force F 1. Conventionally, the action direction of the compression reaction force F1 and the force F2 are the same, whereas in the present invention, the latter force F2 acts in the opposite direction 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 the maximum. Although it is kept small, the compression operation by the piston 34 is performed, and the compression reaction force F 1 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 acts on the drive shaft 18 in the direction to cancel the compression reaction force F1, so that the air conditioner Power consumption during operation stop is reduced. When the operation of the compressor 10 is stopped, that is, when the compression reaction force F 1 of the bistone 34 does not act on the drive shaft 18, there is no force for urging the drive shaft 18 toward the regulation surface. Since the pressure in the housing 11 is higher than the pressure Pa of the outside air, the drive shaft 18 moves away from the rear housing 14 when there is no force to bias the drive shaft 18 toward the regulation surface. The lug plate 36 is moved away from the thrust bearing 37. However, in this embodiment, since the first coil spring 45 always urges the drive shaft 18 toward the rear housing 14 side, the lug plate 36 remains in the thrust even while the compressor 10 is stopped. Are held in contact with the bearings 37. The crank chamber 17 and the suction chamber 19 are communicated through a communication hole 60 formed in the drive shaft 18, and a seal ring 6 is provided on the crank chamber 17 side from the outlet 60 b of the communication hole 60. 3 are provided. Accordingly, the path connecting the crank chamber 17 and the suction chamber 19 is formed by the gap between the first thrust bearing 37, the gap between the lug plate 36 and the inner wall surface 14a of the lya housing 14, and the second gap. The path passes through the gap between the radial bearings 25, the accommodation recess 23, the communication hole 60, and the gap between the first radial bearing 24. As a result, the flow of the refrigerant gas moving 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 is The thrust bearing 37, the second radial bearing 25 and the first radial bearing 24 must pass through, and the bearings 37, 25, 24 are surely lubricated by the lubricating oil in the refrigerant gas. Also, since the refrigerant gas constantly flows into the suction chamber 19 containing the shaft sealing device 26, Lubrication of the shaft sealing device 26 is also performed well. This embodiment has the following effects.

(1) In the housing 11, a suction pressure area for accommodating the shaft sealing device 26 of the drive shaft 18 is provided on the first end side of the first radial bearing 24 with respect to the first radial bearing 24. A communication hole 60 for communicating the pressure region with the crank chamber 17 is formed. The inlet 60 a of the communication hole 60 is formed so as to be located on the second end side of the second radial bearing 25, and the outlet 60 b is located on the second end side of the first radial bearing 24. . 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 and 25, and the lubricating oil contained in the refrigerant gas causes the two radial bearings 24 and 25 to flow. Good lubrication. In addition, the ambient temperature of the shaft sealing device 26 is lowered by the refrigerant gas in the suction pressure region as compared with the conventional configuration, and the durability is improved.

(2) A seal ring 63 is provided on the side of the crank chamber 17 from the outlet 6 Ob of the communication hole 60, and the refrigerant gas force from the crank chamber 17 to the suction pressure region The first thrust bearing 37 and both It passes through the radial bearings 24 and 25 reliably. Therefore, the lubrication of each of the bearings 24, 25, and 37 is performed more favorably. Also, the crankcase

The refrigerant gas in 17 is extracted into the suction chamber 19 only from the communication hole 60 functioning as a bleed passage, so that it is possible to accurately adjust the pressure in the crank chamber 17 when changing the discharge capacity. Will be possible.

(3) The suction chamber 19 and the discharge chamber 20 are provided on the projecting 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 as compared with a conventional compressor that requires a sealing force to withstand a differential pressure between the crankcase 17 having a higher pressure than the suction chamber 19 and the outside air. Therefore, the reliability of the shaft seal is improved. Also, the pressure of the crank chamber 17 against the drive shaft 18 A force F 2 proportional to the pressure difference between P c and the outside air (atmosphere) Pa acts in the opposite direction to the compression reaction force F 1 acting on the drive shaft 18. Therefore, the power for driving the drive shaft 18 can be greatly reduced as compared with the conventional compressor in which the directions of action of the two F 1 and F 2 are the same. Also, the durability of the thrust pairing 37 is improved. These effects, as in the case of using the C 0 ₂ as the refrigerant becomes particularly remarkable when the pressure of the crank chamber 1 in 7 is significantly higher than when using Freon. Further, the stroke of the piston 34 becomes more remarkable in the case of the variable displacement type in which the pressure in the crank chamber 17 becomes higher than that of the fixed displacement type compressor.

(4) The communication hole 60 formed in the drive shaft 18 functions as a bleed passage, and the communication hole 60 is formed with a throttle 61 in the middle. When using C 0 ₂ becomes high pressure in the crank chamber 1 within 7 as refrigerant, extraction air amount to the suction chamber 1 9 with a slight difference in the diameter of the bleed passage is greatly changed, the capacity control accurately Difficult to do. On the other hand, by arranging the throttle unit 61 as in the present embodiment, the capacity control is simplified.

(5) An air supply passage 55 communicating the discharge chamber 20 and the crank chamber 17 is provided, and the opening of the air supply passage 55 is provided by a control valve 56 provided in the middle of the air supply passage 55. Change the pressure in the crankcase 17 to 'adjust. Therefore, the pressure in the crank chamber 17 can be easily adjusted.

(6) The shaft sealing device 26 is made of a mechanical seal, and the mechanical seal has excellent pressure resistance. Therefore, as in the case of using the C_〇 ₂ as the refrigerant, if the pressure in the crank chamber 1 in 7 is significantly higher compared to CFCs, so a particularly effective sealing action. Further, the stroke of the piston 34 is more effective in the case of the variable displacement type in which the pressure in the crank chamber 17 becomes higher than that of the fixed displacement type compressor. The embodiment is not limited to the above, and may be configured as follows, for example. Les ,.

The shaft sealing device 26 does not necessarily need to be disposed in the suction chamber 19, and sucks the chamber 64 as a suction pressure area in which the shaft sealing device 26 is housed, as in the second embodiment shown in FIG. A partition wall 65 defines the inside of the chamber 19, and the suction chamber 19 and the chamber 64 communicate with each other through the hole 65a. In this case, substantially the same effect as in the above embodiment can be expected. When the suction pressure area accommodating the shaft sealing device 26 is formed independently of the suction chamber 19, the suction chamber 19 may be arranged outside the discharge chamber 20. As in the third embodiment shown in FIG. 4, the suction chamber 19 and the discharge chamber 20 may be provided in the rear housing 14 and arranged on the side opposite to the protruding end of the drive shaft 18. The chamber 64 serving as the suction pressure area is communicated with the suction chamber 19 by a passage (not shown). This passage may be an external pipe or a passage formed in the wall of the housing. 'The bleed passage 60 may be formed to have a constant inner diameter by eliminating the throttle portion 61 in the bleed passage 60 in FIG. The compressor is not limited to the variable capacity type, but may be a fixed capacity type compressor. Instead of a structure in which the cam plate (swash plate 38) rotates integrally with the drive shaft 18, the present invention can be applied to a puple-type compressor in which the cam plate is supported to be rotatable relative to the drive shaft and swings. Good. The shaft sealing device is not limited to the mechanical seal 26, and a lip seal may be used. The lip seal allows the shaft sealing device to be constructed at low cost and has the advantage of excellent oil sealing. In particular, in the lip seal 67 of the fourth embodiment shown in FIG. 5, a resin lip ring 67 b and a lip ring 67 c made of a resin such as a fluororesin are held in a main body bracket 67 a. ing. Includes multiple rip rings 67b, 67c As a result, shaft sealing performance is enhanced. A spiral groove 67 d centering on the axis of the drive shaft 18 is formed on the sliding surface of the rip ring 67 b with the drive shaft 18. The helical groove 67 d acts to guide the lubricating oil to the suction chamber 19 by relative rotation with the drive shaft 18, further improving the oil sealing performance of the lip seal 67. The control valves 56 and the like for adjusting the opening degree of the control passage are not limited to the electromagnetic control valves. A so-called internal control valve may be provided which includes a diaphragm that is displaced by the displacement and a valve mechanism that controls the opening degree of the control passage by the displacement of the diaphragm. However, in a clutchless type compressor, an externally controllable solenoid valve is preferable. The drive source of the compressor is not limited to the engine 50, but may be an electric motor. In this case, it can be installed in electric vehicles. In the fifth embodiment shown in FIG. 8, a spiral for returning lubricating oil to the crank chamber 1.7 side with the rotation of the drive shaft 18 is provided on the sliding surface of the seal ring 63 with the drive shaft 18. A groove 63a is formed. In this case, the lubricating oil existing between the seal ring 63 and the drive shaft 18 is sent out to the crank chamber 17 side. As a result, the lubricating oil is not excessively supplied to the suction chamber 19, and there is no possibility that the lubricating oil leaks out of the housing 11 from the shaft sealing device 26. '

Incidentally, instead of forming the spiral groove 63a on the seal ring 63 side, it may be formed on the drive shaft 1'8 side. In this case, the same effect as that formed on the seal ring 63 side can be obtained.

Claims

The scope of the claims

1. A housing having a suction chamber (1 9), a discharge chamber (20) and a crank chamber (17), and having at least one cylinder bore (33);

A drive shaft (18) rotatably supported by the housing, having a first end and a second end, the first end being supported so as to protrude from the housing; and First and second radial bearings (24, 25) supporting first and second ends, respectively;

A piston (34) housed in each of the cylinder pores so as to be able to reciprocate; and a piston (34) housed in the crank chamber (17) for converting the rotational movement of the drive shaft into the reciprocating movement of the piston. A cam plate (3 8) 'operatively connected to Viston,

A shaft sealing device (26) for sealing between the drive shaft and the housing;

The shaft sealing device is housed in the suction chamber (19), and the suction chamber (19) is disposed closer to the first end of the drive shaft than the first radial bearing (24).

A communication hole (60) formed in the drive shaft for communicating the suction chamber (19) with the crank chamber (17); the communication hole has an inlet (60a) and an outlet ( 60b), the inlet (60a) is located on the second end side from the second radial bearing (25), and the outlet (60b) is located from the first radial bearing (24). Be located on the second end side

A swash plate compressor.

2. The swash plate compressor according to claim 1, wherein the discharge chamber (20) is provided on a first end side of the drive shaft with respect to the crank chamber (17).

3. The cam plate (38) is supported on the drive shaft so that its inclination can be changed, and the compressor changes the stroke of the biston by changing the inclination of the cam plate. Or the swash plate type compressor according to 2.

4. The swash plate compressor according to claim 1, wherein the communication hole (60) is provided with a throttle (61) in the middle thereof.

5. The swash plate compressor according to claim 2, wherein the shaft sealing device comprises a mechanical seal (26).

6. The swash plate compressor according to claim 1, wherein the shaft sealing device comprises a lip seal (67).

7. The swash plate type compressor according to claim 1, wherein the second end of the drive shaft is located closer to the second end of the drive shaft than the outlet of the communication hole. A swash plate type compressor equipped with a sealing device (63) for sealing between spaces.

8. The swash plate compressor according to claim 6, wherein the lip seal (67) has a plurality of lip rings.

9. The swash plate compressor according to claim 6, wherein the lip seal (67) is provided with a groove (67d) for returning lubricating oil into the housing as the drive shaft rotates. Swash plate compressor.

10. The swash plate compressor according to claim 1 or 2, wherein a filter is provided in the communication hole.

1 1. The swash plate compressor according to claim 4, wherein a filter is disposed upstream of the throttle section.

1 2. A housing having a suction chamber (1 9), a discharge chamber (20), and a crank chamber (17), and having at least one cylinder bore (33).

A drive shaft (18) rotatably supported by the housing, having a first end and a second end, the first end being supported so as to protrude from the housing; A piston (34) accommodated in the crank chamber (17), which is reciprocally accommodated in the piston, and a piston, which is adapted to convert the rotational movement of the drive shaft into the reciprocating movement of the piston, The operatively connected cam plate (38) and the tilt angle of the cam plate are controlled by controlling the pressure in the crank chamber, and discharge from the cylinder pore to the discharge chamber accompanying the reciprocation of the biston. That the capacity changes

In a swash plate type compressor equipped with

A shaft sealing device (26) for sealing between the drive shaft and the housing, and the shaft sealing device is housed in the suction chamber (19);

A sealing device (63) for sealing between the suction chamber and the crank chamber; and a sealing device formed on one of the sealing device and the drive shaft, and a lubricating oil as the drive shaft rotates. Spiral grooves (63a) that cause the flow of

A swash plate compressor.

13. The swash plate compressor according to claim 12, wherein the spiral groove returns lubricating oil to the crank chamber with rotation of the drive shaft.