WO2016103601A1

WO2016103601A1 - Shaft sealing device and compressor using same

Info

Publication number: WO2016103601A1
Application number: PCT/JP2015/006087
Authority: WO
Inventors: 秋山　訓孝; 亨大隈; 卓瞳高橋
Original assignee: 株式会社デンソー
Priority date: 2014-12-25
Filing date: 2015-12-08
Publication date: 2016-06-30
Also published as: JP2016121762A

Abstract

A shaft sealing device is used in a compressor (51) for compressing a carbon dioxide refrigerant. The shaft sealing device is provided with a rotating ring (22) and a stationary ring (21). The rotating ring is affixed to a shaft (63) located inside a housing (53, 55, 57) for containing a refrigerant. The stationary ring is affixed to a shaft hole (53b) formed in the housing and rotatably supports the shaft passed through the shaft hole. The sealing face between the housing and the stationary ring and/or the sealing face between the shaft and the rotating ring is provided with an annular seal member (23, 24, 25) having an opening and having protrusions (23a, 24a, 25a, 23b, 24b, 25b) formed on both sides of the opening in the radial direction thereof. The seal member is disposed so that the opening is open toward the refrigerant within the housing, and the protrusions are pressed by elasticity against the sealing face between the housing and the stationary ring and/or the sealing face between the shaft and the rotating ring.

Description

Shaft seal device and compressor using the same

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2014-262228 filed on December 25, 2014, the disclosure of which is incorporated herein by reference.

The present disclosure relates to a shaft seal device and a compressor using the shaft seal device.

General compressors have a compression mechanism that generates fluid pressure in the fluid in the housing by rotating the shaft. Such a compressor includes a shaft seal device that prevents fluid from leaking out of the housing through a gap between the housing and the shaft.

In recent years, in such a compressor, carbon dioxide (CO ₂ ), which is replaced with chlorofluorocarbon, is being adopted as a refrigerant gas. When such a refrigerant gas is employed, the pressure acting on the shaft seal device may be 10 times or more than when the fluorocarbon is used. In that case, the load on the shaft seal device is large, and the durability of the shaft seal device is more easily reduced.

As a shaft seal device for the purpose of improving durability, there is a shaft seal device provided with a fixed ring, a rotating ring, a packing (O-ring), and a spring (for example, see Patent Document 1). The stationary ring is fixed to the shaft hole, has an annular shape, and has a stationary-side seal end face on the working part side of the stationary ring. The rotating ring is fixed to a shaft located in the housing, and has a rotating side seal end face that forms an annular shape and is in sliding contact with the fixed side sealing end face on the passive portion side of the rotating ring. The packing is fixed to the shaft and forms an annular shape to seal a gap between the shaft and the rotating ring. The spring is fixed to the shaft and presses the rotating ring in the axial direction out of the housing.

Japanese Patent Laid-Open No. 2007-9886

According to studies by the inventors of the present disclosure, in the shaft seal device of the compressor as described in Patent Document 1, the fixed-side seal end surface and the rotary-side seal end surface slide, and this slide Frictional heat is generated in the moving part. In addition, when carbon dioxide is employed, the ambient temperature of the shaft seal device is higher than that when chlorofluorocarbon is used. Therefore, such a shaft seal device is required to have excellent heat resistance.

Also, in such a compressor, the ambient pressure of the shaft seal device always fluctuates greatly during operation. In such a compressor, the refrigerant repeatedly enters and exits the packing that seals the gap between the shaft and the rotating ring by the pressure of the carbon dioxide refrigerant during operation. At this time, the refrigerant gas that has penetrated into the packing in a high-pressure environment repeats a process of expanding inside the packing during decompression or the like, and a foaming phenomenon occurs in which a crack or the like occurs in the packing. In order to prevent such a phenomenon from occurring, the shaft seal device of such a compressor is required to have excellent foam resistance.

Also, the molecular weight of carbon dioxide is lower than that of chlorofluorocarbon. For this reason, in such a compressor, the permeability is very high, and carbon dioxide tends to leak out of the housing through the packing that seals the gap between the shaft and the rotating ring. In order to prevent such a phenomenon from occurring, the shaft seal device of such a compressor is also required to have excellent carbon dioxide permeation resistance.

Also, the compressor mounted on the vehicle air conditioner may be used at a very low temperature. For this reason, such a shaft seal device of a compressor is also required to ensure airtightness even at extremely low temperatures.

As described above, such a shaft seal device of a compressor is required to be excellent in heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic resistance.

However, the compressor described in Patent Document 1 is configured to seal the contact surface (seal part) between the shaft and the rotating ring by packing (O-ring). Such a packing is generally made of a rubber material. However, when packing is made of rubber material, it is difficult to satisfy the four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic temperature resistance. Difficult to maintain.

The present disclosure has been made in view of the above points, and an object of the present disclosure is to provide a shaft seal device capable of maintaining the sealing performance of the seal surface for a longer period of time and a compressor using the same.

The shaft seal device of the present disclosure is used for a compressor that compresses a refrigerant of carbon dioxide. The shaft seal device includes a rotating ring and a fixed ring. The rotating ring is fixed to a shaft located inside the housing that houses the refrigerant. The fixed ring is fixed to a shaft hole formed in the housing, and rotatably supports a shaft inserted through the shaft hole. At least one of the sealing surface of the housing and the stationary ring and the sealing surface of the shaft and the rotating ring is provided with an annular sealing member having an opening and having protrusions formed on both sides in the radial direction of the opening. ing. The seal member is disposed such that the opening portion opens toward the refrigerant side inside the housing, and the protrusion portion is pressed against the seal surface by elasticity.

Here, as the seal member, a resin that satisfies the four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic temperature resistance can be used. Such a resin seal member can satisfy, for example, four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance, and cryogenic resistance that cannot be satisfied by a rubber material, and further elastic deformation. Since the protrusions formed on both outer sides of the opening can be pressed against the sealing surface, the sealing performance of the sealing surface can be maintained for a longer period of time.

The compressor of the present disclosure uses the above-described shaft seal device for sealing around the shaft.

The above and other objects, features, and advantages of the present disclosure will become more apparent from the following detailed description with reference to the accompanying drawings.
It is a longitudinal section of the compressor concerning a 1st embodiment. It is an enlarged view of the Z section in FIG. It is sectional drawing of the contact surface of the rotating ring and shaft of the shaft-seal apparatus which concerns on 1st Embodiment. It is the figure which showed the mode of the cross section of the U-ring of the shaft seal device which concerns on 1st Embodiment. It is a figure for demonstrating the action | operation of a U ring. It is the figure which compared the characteristic of the various rubber materials at the time of the refrigerant | coolant of a carbon dioxide. It is the figure which showed the structure of the U-ring of the shaft seal apparatus which concerns on 2nd Embodiment. It is a figure which shows the spring member used for the U-ring shown in FIG. It is the figure which showed the structure of the U-ring of the shaft seal apparatus which concerns on 3rd Embodiment. It is a figure which shows the spring member used for the U-ring shown in FIG.

Hereinafter, a plurality of embodiments for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, portions corresponding to those described in the preceding embodiment may be denoted by the same reference numerals, and redundant description may be omitted. When only a part of the configuration is described in each embodiment, the other parts of the configuration are the same as those of the embodiment described above. In addition to the combination of parts specifically described in each embodiment, the embodiments may be partially combined as long as the combination does not hinder.

(First embodiment)
Hereinafter, the compressor and the shaft seal device according to the first embodiment will be described with reference to FIGS. 1 to 6. The compressor according to the present embodiment changes the stroke of the reciprocating piston by changing the inclination angle of the swash plate arranged to be inclined with respect to the center line of the drive shaft, thereby reducing the discharge capacity of the compressor. The swash plate compressor 51 is changed. The swash plate compressor 51 is a compressor that compresses a refrigerant of carbon dioxide. The swash plate compressor 51 is applied to an air conditioner such as an automobile.

The swash plate compressor 51 has a bottomed cylindrical front housing 53. A cylinder block 55 is provided at the opening of the bottomed cylindrical front housing 53 so as to close the opening. A rear housing 57 is provided in the cylinder block 55.

Radial bearings

59 and 61 are provided at the center of the bottom wall 53a of the front housing 53 and the center of the cylinder block 55, respectively. A shaft 63 is pivotally supported between the

radial bearings

59 and 61. The front housing 53, the cylinder block 55, and the rear housing 57 constitute a housing that stores the refrigerant.

Further, a shaft seal device 20 called a mechanical seal is provided on the bottom wall 53a of the front housing 53 on the front side (the left side in the drawing) from the radial bearing 59. The shaft seal device 20 prevents the refrigerant from leaking out of the front housing 53 through the gap between the front housing 53 and the shaft 63. The shaft seal device 20 will be described in detail later.

On the bottom wall 53 a of the front housing 53, a disk-shaped lug plate 73 fixed to the shaft 63 is provided. A thrust bearing 75 is interposed between the lug plate 73 and the bottom wall 53a, and receives an axial load due to a piston compression reaction force.

A swash plate 77 is provided between the lug plate 73 of the shaft 63 and the cylinder block 55 so as to be rotatable with respect to the axial direction of the shaft 63. The swash plate 77 and the lug plate 73 are coupled so as to be tiltable by a link mechanism 79 provided on the lug plate 73 and a pin 81 provided on the swash plate 77, and the rotation of the lug plate 73 is inclined. Transmit to the plate 77.

In the cylinder block 55, cylinder bores 83 are formed at equal intervals in the circumferential direction. The cylinder bore 83 is disposed parallel to the axis of the shaft 63, and a piston 85 is inserted therein so as to be able to reciprocate.

This piston 85 is provided with a spherical bearing 87. The spherical bearing 87 is engaged with a pair of shoes 89 holding the outer peripheral portion of the swash plate 77 so as to be slidable in the circumferential direction.

A valve plate 91 is interposed between the cylinder block 55 and the rear housing 57. A suction valve 93 is provided between the valve plate 91 and the cylinder block 55 to seal the suction port.

A suction chamber 95 and a discharge chamber 97 are provided inside the rear housing 57. In a discharge chamber 97 on the rear housing 57 side of the valve plate 91, a discharge valve 99 and a retainer 101 that regulates the valve lift amount are fastened to the valve plate 91 by bolts or the like.

The rear housing 57 is provided with a control valve 103, which introduces a control gas into the swash plate chamber 71 to adjust the inclination angle of the swash plate and set the discharge capacity. A passage for introducing control gas from the control valve 103 to the swash plate chamber 71 is formed in the cylinder block 55, the rear housing 57, the valve plate 91, etc., but is not shown here.

Next, the shaft seal device 20 of this embodiment will be described. The shaft seal device 20 seals the periphery of the shaft 63. The shaft seal device 20 is a balanced shaft seal device. The shaft seal device 20 is provided in a shaft hole 53 b formed in the center portion of the bottom wall 53 a of the front housing 53. As shown in FIG. 2, the shaft seal device 20 includes a fixed ring 21, a rotating ring 22, a spring 27, and a bracket 28.

The fixed ring 21 is made of, for example, silicon carbide, and is fixed to the shaft hole 53b. The shaft hole 53 b is formed in the front housing 53. The fixed ring 21 rotatably supports the shaft 63 inserted through the shaft hole 53b. The shaft 63 passes through the front housing 53 via the shaft hole 53b. One end of the shaft 63 is located outside the front housing 53. The fixed ring 21 has an annular shape, and has a fixed-side seal end face 21 a on the side adjacent to the rotating ring 22 (right side in the figure).

The rotary ring 22 is made of carbon, for example, and is fixed to a shaft 63 located inside the front housing 53. The rotating ring 22 has an annular shape, and has a rotating side seal end face 22a on the side adjacent to the fixed ring 21 (left side in the figure). The rotating ring 22 rotates integrally with the shaft 63.

The spring 27 is, for example, a coil spring, and is fixed to the shaft 63 via the bracket 28. Further, the spring 27 urges the rotary ring 22 in the axial direction toward the front side (left side in the drawing) of the front housing 53.

The bracket 28 forms the seating surface of the spring 27. The bracket 28 is fixed to the shaft 63 and rotates integrally with the shaft 63 and the rotary ring 22.

Further, U-rings 23 corresponding to sealing members are respectively provided on the contact surface (seal surface) of the shaft hole 53b of the housing of the fixed ring 21 and the front housing 53 and the contact surface (seal surface) of the rotary ring 22 and the shaft 63. Is provided.

Specifically, a U-ring insertion groove 210 is formed on the outer peripheral surface of the stationary ring 21. In the U-ring insertion groove 210, a flexible resin U-ring 23 is disposed. The U ring 23 seals the contact surface (seal surface) between the stationary ring 21 and the shaft hole 53 b of the front housing 53.

Further, a U-ring insertion groove 220 is formed on the inner peripheral surface of the rotary ring 22. Also in the U-ring insertion groove 220, a flexible resin U-ring 23 is arranged. The contact surface (seal surface) between the rotating ring 22 and the shaft 63 is sealed by the U ring 23. The configuration and material of each U-ring 23 are the same.

FIG. 3 is a cross-sectional view of the contact surface between the rotating ring 22 and the shaft 63. FIG. 4 is a view showing a cross section of the U-ring 23 of the shaft seal device according to the present embodiment. The U-ring 23 is an annular seal member, and has a U-shape from an outer seal wall portion and an inner seal wall portion that face each other in the radial direction in a cross section, and a seal bottom portion that connects both seal wall portions. The seal bottom portion connects one end side of the shaft 63 positioned outside the front housing 53 at the outer seal wall portion and the inner seal wall portion. On the other hand, an annular opening is formed between the open end of the outer seal wall and the open end of the inner seal wall.

In the cross section of the U-ring 23 shown in FIG. 3, a protrusion 23a and a protrusion 23b are formed on both sides (both open ends) in the radial direction of the opening. That is, the protrusion 23a is provided on the radially outer side of the open end of the outer seal wall, and the protrusion 23b is provided on the radially inner side of the open end of the inner seal wall. The protrusion 23a and the protrusion 23b protrude from both sides in the radial direction of the opening. More specifically, the protrusion 23a protrudes radially outward from the outer seal wall, and the protrusion 23b protrudes radially inward from the inner seal wall.

The U ring 23 is made of PTFE (polytetrafluoroethylene) which is a fluorocarbon resin.

The U-ring 23 is arranged so that the opening opens toward the refrigerant side inside the housing. That is, the U-ring 23 is provided so that the opening portion opens toward the side opposite to one end of the shaft 63 located outside the front housing 53. The U-ring 23 has a dimensional structure in which the

protrusions

23a and 23b are pressed against the seal surface by elasticity. That is, as shown in FIG. 5, when the pressure P of the refrigerant inside the housing increases, the U-ring 23 is elastically deformed to expand the opening, and the shaft 63 rotates with the

protrusions

23a and 23b. The force F that holds down the ring 22 works. Thereby, the

protrusions

23a and 23b seal the contact surface (seal surface) between the rotating ring 22 and the shaft 63 with a strong force.

Also, an annular metal spring member 230 is provided at the opening of the U-ring 23. This spring member 230 pushes and widens the opening of the U-ring 23. By the spring member 230, the protrusion 23a and the protrusion 23b of the U-ring 23 are more strongly pressed against the seal surface.

Note that the spring member 230 in the present embodiment has a W-shaped cross section. The spring member 230 expands the opening even when the pressure of the refrigerant inside the housing is low, and the protrusion 23a and the protrusion 23b are pressed against the seal surface.

In the above configuration, when the shaft 63 is rotated by an external driving force (for example, a vehicle engine), the lug plate 73 fixed to the shaft 63 is rotated, and the swash plate 77 connected by the pin 81 and the link mechanism portion 79 is rotated. . Here, the outer peripheral portion of the swash plate 77 is gripped by a shoe 89 so as to be slidable in the circumferential direction, and the shoe 89 is slidably engaged with a spherical bearing of the piston 85. Accordingly, the rotational swing motion of the swash plate 77 is converted into the reciprocating motion of the piston 85, and the fluid in the cylinder is discharged or sucked.

In such a shaft seal device 20 of the swash plate compressor 51, (A) a contact surface between the fixed-side seal end surface 21a and the rotation-side seal end surface 22a, (B) a contact surface between the rotation ring 22 and the shaft 63, (C) At three locations on the contact surface of the shaft ring 53b of the stationary ring 21 and the housing of the front housing 53, seal portions that prevent leakage of the refrigerant to the outside are generated. Hereinafter, the seals shown in (A) to (C) will be described.

(A) When the seal shaft 63 of the contact surface between the fixed-side seal end surface 21a and the rotation-side seal end surface 22a rotates, the fixed-side seal end surface 21a of the fixed ring 21 and the rotation-side seal end surface 22a of the rotation ring 22 are connected to the spring 27 and The slider slides while being pressed by the refrigerant internal pressure of the compressor. Lubricating oil is mixed in the carbon dioxide refrigerant used as the refrigerant. The lubricating oil is drawn into the contact surface between the fixed-side seal end surface 21a of the fixed ring 21 and the rotary-side seal end surface 22a of the rotating ring 22, whereby an oil film is formed. Thus, the minute gap between the fixed-side seal end surface 21a and the rotation-side seal end surface 22a is filled with the lubricating oil, and the refrigerant in the housing is sealed so as not to leak to the outside.

Even if the shaft 63 is displaced in the axial direction, the spring 27 allows the rotation ring 22 to move in the axial direction of the shaft 63, so that the fixed-side seal end surface 21 a of the fixed ring 21 and the rotation-side seal of the rotation ring 22 are allowed. The seal of the end face 22a is maintained.

(B) Sealing of the contact surface between the rotating ring 22 and the shaft 63 An annular U-ring 23 having a U-shape in cross section is provided on the contact surface (seal surface) of the shaft 63 and the rotating ring 22. In the present embodiment, the U ring 23 is made of resin. The U-ring 23 has

protrusions

23a and 23b on both sides in the radial direction of the opening. The

protrusions

23a and 23b are pressed against the sealing surface by elasticity, and the sealing surfaces of the shaft 63 and the rotary ring 22 are sealed.

(C) Sealing of the contact surface between the fixed ring 21 and the shaft hole 53b of the front housing 53 The contact surface (seal surface) of the fixed ring 21 and the shaft hole 53b of the front housing 53 has protrusions 23a on both outer sides of the opening. An annular resin U-ring 23 having a U-shaped cross section with 23b formed therein is provided. The

protrusions

23 a and 23 b are pressed against the sealing surface by elasticity, and the sealing surface of the stationary ring 21 and the shaft hole 53 b of the front housing 53 is sealed.

Since the swash plate compressor 51 employs carbon dioxide as a refrigerant, the shaft seal device 20 satisfies the four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic resistance. Is required.

The two U rings 23 provided in the shaft seal device 20 of the present embodiment are each made of PTFE (polytetrafluoroethylene) which is a fluorocarbon resin. Here, with reference to FIG. 6, various characteristics comparison between various rubber materials and PTFE which is resin will be described.

EPDM (ethylene propylene rubber) is inferior in all of heat resistance, carbon dioxide permeation resistance, foam resistance and cryogenic temperature. Moreover, although HNBR (nitrile rubber) for high temperature is excellent in heat resistance, carbon dioxide permeation resistance and cryogenic temperature, it is inferior in foaming resistance. Moreover, VMQ (silicone rubber) is inferior in carbon dioxide permeation resistance although it is excellent in heat resistance, foam resistance and cryogenic temperature. FKM (fluoro rubber) is excellent in heat resistance and carbon dioxide permeation resistance, but is inferior in foam resistance and cryogenic temperature. As described above, the rubber agent cannot satisfy the four requirements of heat resistance, carbon dioxide permeation resistance, foam resistance and cryogenic temperature.

On the other hand, the two U-rings 23 provided in the shaft seal device 20 of the present embodiment are made of PTFE (polytetrafluoroethylene) which is a flexible resin. PTFE satisfies four requirements of heat resistance, carbon dioxide permeation resistance, foam resistance and cryogenic temperature.

According to the configuration described above, the shaft seal device 20 is provided with the U-ring 23 on each of the seal surface of the housing and the stationary ring 21 and the seal surface of the shaft 63 and the rotary ring 22. The U-ring 23 is disposed so that the opening portion opens toward the refrigerant side inside the housing, and the

protrusions

23a and 23b formed on both sides in the radial direction of the opening portion are pressed against the sealing surface by elasticity. As a material for forming the U-ring 23, a resin that satisfies the four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic resistance can be used. Such a resin U-ring 23 can satisfy, for example, four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic resistance that cannot be satisfied by a rubber material. Further, the U-ring 23 is elastically deformed, so that the

protrusions

23a and 23b are pressed against the seal surface. Thereby, the sealing performance of a sealing surface can be maintained over a long period of time.

Further, on the seal surface of the shaft 63 and the rotary ring 22, the rotary ring 22 biased by the spring 27 may move in the axial direction of the shaft 63 together with the shaft 63. By providing the U-ring 23 on the sealing surface, it is possible to effectively perform the sealing.

Also, as a resin that can satisfy the four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance and cryogenic temperature resistance, for example, PTFE (polytetrafluoroethylene) can be used.

Further, the U-ring 23 has a spring member 230 that pushes the opening of the U-ring 23, and the

protrusions

23a and 23b are pressed against the seal surface by the spring member 230, so that the pressure of the refrigerant inside the housing is low. Even in this case, the sealing property can be ensured.

(Second Embodiment)
Hereinafter, a compressor and a shaft seal device according to the second embodiment will be described with reference to FIGS. 7 and 8. The U-ring 23 in the first embodiment has a spring member 230 having a W-shaped cross section. On the other hand, the U-ring 24 in this embodiment has two annular plate-

like spring members

240 and 241 having different diameters.

The U-ring 24 is an annular seal member, and has a U-shape including an outer seal wall portion and an inner seal wall portion that are opposed in the radial direction in a cross section, and a seal bottom portion that couples both seal wall portions. The seal bottom portion connects one end side of the shaft 63 positioned outside the front housing 53 at the outer seal wall portion and the inner seal wall portion. On the other hand, an annular opening is formed between the open end of the outer seal wall and the open end of the inner seal wall.

In the cross section of the U-ring 24 shown in FIG. 7, a protrusion 24a and a protrusion 24b are formed on both sides (both open ends) in the radial direction of the opening. That is, the protrusion 24a is provided on the radially outer side of the open end of the outer seal wall, and the protrusion 24b is provided on the radially inner side of the open end of the inner seal wall. The protrusion 24a and the protrusion 24b protrude from both sides in the radial direction of the opening. More specifically, the protrusion 24a protrudes radially outward from the outer seal wall, and the protrusion 24b protrudes radially inward from the inner seal wall.

The

spring members

240 and 241 are each composed of a thin metal plate formed in an annular shape, and are elastically deformed.

The spring member 240 is disposed on the wall surface on the opposite side of the protruding portion 24a in the outer seal wall portion of the U-ring 24. The spring member 240 is slightly larger than the outer seal wall portion (the outer peripheral side surface of the opening) of the U ring 24 before being placed on the wall surface of the U ring 24. In other words, the diameter of the spring member 240 is slightly larger than the diameter of the opening of the U-ring 24 in a state before being arranged at the opening of the U-ring 24. Therefore, when arranged in the opening of the U-ring 24, a force acts radially outward as shown in FIG.

Further, the spring member 241 is disposed on the wall surface on the opposite side of the projecting portion 24b in the inner seal wall portion of the U ring 24. The spring member 241 is slightly smaller than the inner seal wall portion (the inner peripheral side surface of the opening) of the U ring 24 before being disposed on the wall surface of the U ring 24. In other words, the diameter of the spring member 241 is slightly smaller than the diameter of the opening of the U-ring 24 in a state before being arranged at the opening of the U-ring 24. Therefore, when arranged at the opening of the U-ring 24, a force acts radially inward as shown in FIG.

These

spring members

240 and 241 open the opening even when the pressure of the refrigerant inside the housing is low, and the protrusion 24a and the protrusion 24b are pressed against the seal surface.

Such U-rings 24 are provided on the contact surface (seal surface) of the shaft hole 53b of the stationary ring 21 and the front housing 53, and on the contact surface (seal surface) of the rotary ring 22 and the shaft 63, respectively.

In this embodiment, it is possible to obtain the same effect as that of the first embodiment, which is obtained from the configuration common to the first embodiment.

In addition, the U-ring 24 including the

spring members

240 and 241 formed of a metal thin plate in an annular shape as in the present embodiment can be reduced in cost because of its simple configuration. Miniaturization is also possible.

In addition, although this embodiment is embodiment based on 1st Embodiment, it is also possible to combine this embodiment with either of the above-mentioned 1st Embodiment.

(Third embodiment)
Hereinafter, a compressor and a shaft seal device according to a third embodiment will be described with reference to FIGS. 9 and 10. The spring member 230 of the U-ring 23 in the first embodiment is W-shaped in cross section. On the other hand, the spring member 250 of the U ring 25 in the present embodiment has a U shape in cross section.

The U-ring 25 is an annular seal member, and has a U shape from an outer seal wall portion and an inner seal wall portion that are opposed in the radial direction in a cross section, and a seal bottom portion that couples both seal wall portions. The seal bottom portion connects one end side of the shaft 63 positioned outside the front housing 53 at the outer seal wall portion and the inner seal wall portion. On the other hand, an annular opening is formed between the open end of the outer seal wall and the open end of the inner seal wall.

In the cross section of the U-ring 25 shown in FIG. 9, a protrusion 25a and a protrusion 25b are formed on both sides (both open ends) in the radial direction of the opening. That is, the protrusion 25a is provided on the radially outer side of the open end of the outer seal wall, and the protrusion 25b is provided on the radially inner side of the open end of the inner seal wall. The protrusion 25a and the protrusion 25b protrude from both sides in the radial direction of the opening. More specifically, the protrusion 25a protrudes radially outward from the outer seal wall, and the protrusion 25b protrudes radially inward from the inner seal wall.

The spring member 250 is formed by forming a thin metal plate into an annular shape, and has a U-shape in cross section. When the spring member 250 is disposed at the opening of the U-ring 24, a force acts in the direction of opening the opening of the spring member 250 as shown in FIG.

The spring member 250 expands the opening even when the pressure of the refrigerant inside the housing is low, and the protrusion 25a and the protrusion 25b are pressed against the seal surface.

Such U-rings 25 are provided on the contact surface (seal surface) of the shaft hole 53b of the stationary ring 21 and the front housing 53, and on the contact surface (seal surface) of the rotary ring 22 and the shaft 63, respectively.

Further, since the U-ring 25 including the spring member 250 having a U-shaped cross section as in the present embodiment has a simple configuration, the cost can be reduced, and the shaft seal device 20 can be downsized. Is possible.

(Other embodiments)
In the first to third embodiments, the compressor of the present disclosure has been described by taking a swash plate compressor using carbon dioxide as a refrigerant as an example, but can be applied to various compressors other than the swash plate compressor. .

In the first to third embodiments, the balance type shaft seal device has been described as an example. However, the present invention is not limited to such a type shaft seal device. For example, an unbalanced shaft seal device may be used. It can also be applied.

In the first to third embodiments, the U-rings 23, 24, and 25 have a U-shaped cross section, but may have a V-shaped cross section, for example.

In the first to third embodiments,

spring members

230, 240, 241, and 250 are provided at the openings of the U-rings 23, 24, and 25. However, it is not always necessary to provide such a spring member.

In the first to third embodiments, the U-rings 23, 24, and 25 are made of PTFE (polytetrafluoroethylene). However, you may comprise by resin other than PTFE which satisfy | fills four requirements of heat resistance, foam resistance, carbon dioxide permeation resistance, and cryogenic temperature resistance.

The U-ring 23 of the first embodiment includes a spring member 230 having a W-shaped cross section, and the U-ring 25 of the second embodiment includes a spring member 250 having a U-shaped cross section. However, for example, the U-ring may be provided with a spring member having a V-shaped cross section.

In the first to third embodiments, U rings 23, 24, and 25 are provided on both the seal surfaces of the front housing 53 and the stationary ring 21 and the seal surfaces of the shaft 63 and the rotating ring 22. However, the U rings 23, 24, and 25 may be provided on any one of the seal surface of the front housing 53 and the stationary ring 21 and the seal surface of the shaft 63 and the rotating ring 22. Further, a U-ring may be provided on the seal surfaces of the shaft 63 and the rotary ring 22, and for example, the seal surfaces of the front housing 53 and the fixed ring 21 may be joined so that the sealing performance is maintained.

In the first to third embodiments, the U rings 23, 24, and 25 are provided on the contact surface of the stationary ring 21 with the front housing 53. However, the U ring 23 is disposed on the contact surface of the front housing 53 with the stationary ring 21. , 24, 25 may be provided. In the first and second embodiments, the U-rings 23, 24, 25 are provided on the contact surface of the rotating ring 22 with the shaft 63. However, the U-rings 23, 24 are provided on the contact surface of the shaft 63 with the rotating ring 22. 25 may be provided.

Note that the present disclosure is not limited to the above-described embodiment, and can be appropriately changed without departing from the gist of the present disclosure. In each of the above embodiments, when referring to the material, shape, positional relationship, etc. of the constituent elements, etc., unless otherwise specified, or in principle limited to a specific material, shape, positional relationship, etc. The material, shape, positional relationship, etc. are not limited.

Claims

A shaft seal device of a compressor (51) for compressing a carbon dioxide refrigerant,
A rotating ring (22) fixed to a shaft (63) located inside a housing (53, 55, 57) containing the refrigerant;
A fixed ring (21) fixed to a shaft hole (53b) formed in the housing and rotatably supporting the shaft inserted through the shaft hole;
At least one of the sealing surface of the housing and the stationary ring and the sealing surface of the shaft and the rotary ring has an opening, and protrusions (23a, 24a, 25a, 23b, 24b, 25b) are provided with annular sealing members (23, 24, 25),
The seal member is a shaft seal device in which the opening is disposed so as to open toward the refrigerant inside the housing, and the protrusion is elastically pressed against the seal surface.
The shaft seal device according to claim 1, wherein the seal member is a U-ring having a U-shaped cross section.
The shaft seal device according to claim 1 or 2, wherein the seal member is provided on a seal surface of the shaft and the rotary ring.
The shaft seal device according to any one of claims 1 to 3, wherein the seal member is made of PTFE.
The seal member has spring members (230, 240, 241, 250) that spread the opening of the seal member,
The shaft sealing device according to claim 1, wherein the protrusion is pressed against the seal surface by the spring member.
The shaft seal device according to claim 5, wherein the spring member has a U-shaped, V-shaped, or W-shaped cross section.
A compressor using the shaft seal device according to any one of claims 1 to 6 for sealing around the shaft.