WO2016103602A1

WO2016103602A1 - Shaft-sealing device and compressor

Info

Publication number: WO2016103602A1
Application number: PCT/JP2015/006088
Authority: WO
Inventors: 亨大隈; 秋山　訓孝; 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: JP2016121761A

Abstract

The present invention is a shaft-sealing device (20) for a compressor (51) and is provided with a rotating ring (22), which is fixed on a shaft (63) that is located inside a housing (53, 55, 57), and a fixed ring (21), which is fixed to a shaft hole formed in the housing and is for rotatably supporting the shaft that is inserted in the shaft hole. Multiple O-rings (23-26) for sealing between the housing and the fixed ring and/or between the shaft and the rotating ring are provided so as to line up side by side in the axial direction of the shaft. Of the multiple O-rings, the O-rings disposed on the coolant side towards the interior of the housing have better anti-foaming properties than the O-rings disposed on the atmospheric side towards the exterior of the housing. The O-rings disposed on the atmospheric side have better permeability resistance than the O-rings disposed on the coolant side. Such a configuration is able to satisfy the two requirements for anti-foaming properties and permeability resistance and is able to maintain sealing properties of the sealing surfaces for longer periods.

Description

Shaft seal device and compressor

Cross-reference of related applications

This application is based on Japanese Patent Application No. 2014-262227 filed on Dec. 25, 2014, the disclosure of which is incorporated herein by reference.

The present disclosure relates to a shaft seal device for a compressor that compresses a carbon dioxide refrigerant and a compressor.

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.

Recently, in such compressors, carbon dioxide (CO2) instead of Freon is being adopted as a refrigerant gas. When such a refrigerant gas is employed as the fluid to be compressed, the pressure acting on the shaft seal device may be 10 times or more than when using chlorofluorocarbon. In this case, the load on the shaft seal device is large, and the durability of the shaft seal device may be further reduced.

Therefore, in order to improve the durability, it is fixed to the shaft hole, and is fixed to the shaft that is fixed to the shaft located in the housing and the fixed ring having the fixed side seal end surface on the working part side of the fixed ring. A rotating ring having a rotating side seal end face that is in sliding contact with the fixed side seal end face on the passive part side of the rotating ring, and a packing (O-ring) that is fixed to the shaft and seals the gap between the shaft and the rotating ring; There is a shaft seal device provided with a spring that is fixed to a shaft and presses the rotating ring in the axial direction outside the housing (see, for example, Patent Document 1).

Japanese Patent Laid-Open No. 2007-9886

According to the inventors' investigation, the atmospheric pressure of the shaft seal device always fluctuates greatly during operation of the compressor as described above. In such a shaft seal device of the 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 under a high-pressure environment may repeat the process of expanding inside the packing during decompression or the like, which may cause a foaming phenomenon in which a crack or the like occurs in the packing. In order to prevent such a phenomenon from occurring, the packing used in 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 carbon dioxide 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 and the housing and the stationary ring. In order to prevent such a phenomenon from occurring, the packing used in the shaft seal device of such a compressor is also required to have excellent permeation resistance.

With a compressor that seals the contact surface (seal surface) of the shaft and rotating ring with one packing, it may be difficult to meet the requirements for foam resistance and permeation resistance with one packing. It may be difficult to maintain the sealing performance of the sealing surface over a long period of time.

This disclosure is intended to maintain the sealing performance of the sealing surface for a longer period of time.

A shaft seal device according to an aspect of the present disclosure is a shaft seal device for a compressor that compresses a carbon dioxide refrigerant, and is formed in a housing and a rotating ring fixed to a shaft positioned inside a housing that stores the refrigerant. A fixed ring that is fixed to the shaft hole and rotatably supports the shaft inserted through the shaft hole. A plurality of O-rings for sealing at least one of the housing and the fixed ring and between the shaft and the rotating ring are provided so as to be aligned in the axial direction of the shaft. Among the plurality of O-rings, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing. The O-ring arranged on the atmosphere side outside the housing has better permeation resistance than the O-ring arranged on the refrigerant side inside the housing.

According to such a configuration, the plurality of O-rings sealing at least one of the housing and the stationary ring and between the shaft and the rotating ring are provided so as to be aligned in the axial direction of the shaft. Of the plurality of O-rings arranged in the axial direction of the shaft, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing. Therefore, this O-ring can satisfy the foaming resistance requirement. Further, since the O-ring arranged on the atmosphere side outside the housing has better permeation resistance than the O-ring arranged on the refrigerant side inside the housing, the O-ring arranged on the atmosphere side outside this housing The ring can meet the requirements of permeation resistance. Thus, the two requirements of foaming resistance and permeation resistance can be satisfied, and the sealing performance of the sealing surface can be maintained for a longer period.

A shaft seal device according to another aspect of the present disclosure is a shaft seal device for a compressor that compresses a carbon dioxide refrigerant, and is formed in a housing and a rotating ring fixed to a shaft positioned inside the housing that stores the refrigerant. A fixed ring that is fixed to the shaft hole and rotatably supports the shaft inserted through the shaft hole. At least one of a plurality of O-rings sealing between the housing and the fixed ring and a plurality of O-rings sealing between the shaft and the rotating ring is provided. Among the plurality of O-rings, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing. The O-ring arranged on the atmosphere side outside the housing has better permeation resistance than the O-ring arranged on the refrigerant side inside the housing.

According to such a configuration, at least one of a plurality of O-rings sealing between the housing and the fixed ring and a plurality of O-rings sealing between the shaft and the rotating ring is provided. Of the plurality of O-rings arranged in the axial direction of the shaft, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing. Therefore, this O-ring can satisfy the foaming resistance requirement. Further, since the O-ring arranged on the atmosphere side outside the housing has better permeation resistance than the O-ring arranged on the refrigerant side inside the housing, the O-ring arranged on the atmosphere side outside this housing The ring can meet the requirements of permeation resistance. Thus, the two requirements of foaming resistance and permeation resistance can be satisfied, and the sealing performance of the sealing surface can be maintained for a longer period.

It is a longitudinal section of the swash plate type compressor concerning a 1st embodiment of this indication. It is the Z section enlarged view in FIG. It is the figure which compared the characteristic in the use environment of the carbon dioxide refrigerant of various rubber materials. It is sectional drawing of the shaft seal apparatus of the swash plate type compressor which concerns on 2nd Embodiment of this indication.

Hereinafter, a plurality of modes for carrying out the present disclosure will be described with reference to the drawings. In each embodiment, parts corresponding to the matters 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 mode, the other modes described above can be applied to the other parts of the configuration. Not only combinations of parts that clearly show that combinations are possible in each embodiment, but also combinations of the embodiments even if they are not explicitly stated unless there is a problem with the combination. Is also possible.

(First embodiment)
Hereinafter, the compressor and the shaft seal device according to the first embodiment of the present disclosure will be described with reference to FIGS. 1 to 3. 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 carbon dioxide refrigerant. 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, and a rear housing 57 is provided at the cylinder block 55.

Radial bearings

59 and 61 are provided at the center portion of the bottom wall 53 a of the front housing 53 and the center portion of the cylinder block 55, and 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.

A shaft seal device 20 generally 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 is for preventing 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.

A disk-shaped lug plate 73 fixed to the shaft 63 is provided on the upper side of the bottom wall 53 a of the front housing 53. 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 at a portion of the shaft 63 between the lug plate 73 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. This is transmitted 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 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, and a suction valve 93 is provided between the valve plate 91 and the cylinder block 55 to seal the suction port. It is like that.

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, and a control gas is introduced 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 the swash plate compressor 51 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 stationary ring 21 has an annular shape, and has a stationary-side seal end face 21a on the rotating ring 22 side (right side in the drawing).

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 stationary ring 21 side (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 a seating surface of the spring 27, is fixed to the shaft 63, and rotates integrally with the shaft 63 and the rotary ring 22.

Between the fixed ring 21 and the shaft hole 53b (for example, a contact surface), two O-

rings

23 and 24 are provided so as to be aligned in the axial direction of the shaft 63. Specifically, two

groove portions

210 and 211 are formed on the outer peripheral surface of the fixed ring 21, and O-

rings

23 and 24 are disposed in these

groove portions

210 and 211, respectively. The O-

rings

23 and 24 seal the gap between the stationary ring 21 and the shaft hole 53b.

Further, two O-

rings

25 and 26 are provided between the rotary ring 22 and the shaft 63 (for example, a contact surface) so as to be aligned in the axial direction of the shaft 63. Specifically, two

grooves

220 and 221 are formed on the inner peripheral surface of the rotating ring 22, and O-

rings

25 and 26 are disposed in these

grooves

220 and 221, respectively. The O-

rings

25 and 26 seal the gap between the rotary ring 22 and the shaft 63.

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 so as to be slidable in the circumferential direction, and the shoe 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 and sucked.

In the shaft seal device 20 having the above-described configuration, when the shaft 63 rotates, the fixed-side seal end surface 21a of the fixed ring 21 and the rotation-side seal end surface 22a of the rotary ring 22 are pressed by the spring 27 and the refrigerant internal pressure of the compressor. It slides while being done. In addition, lubricating oil is mixed in the carbon dioxide refrigerant used as the refrigerant gas, and this lubricating oil is drawn into the contact surface between the stationary seal end surface 21a of the stationary ring 21 and the rotational sealing end surface 22a of the rotating ring 22. As a result, 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 housing is sealed so that the refrigerant in the housing does not leak to the outside.

Further, 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 end surface of the rotation ring 22 are allowed. The 22a seal is maintained.

Further, O-

rings

25 and 26 are provided between the rotary ring 22 and the shaft 63 (seal surface). The space between the rotary ring 22 and the shaft 63 (seal surface) is sealed by these O-

rings

25 and 26. Here, the O-ring 25 arranged in the inner (refrigerant side) direction of the housing is more excellent in foam resistance than the O-ring 26 arranged in the outer direction of the housing. Further, the O-ring 26 disposed in the outer (atmosphere side) direction of the housing is superior in permeation resistance than the O-ring 25 disposed in the inner direction of the housing. Specifically, the O-ring 25 is made of silicon rubber having excellent foam resistance, and the O-ring 26 is made of fluorine rubber or nitrile rubber having excellent permeation resistance.

Further, O-

rings

23 and 24 are provided between the fixed ring 21 and the shaft hole 53 b of the front housing 53 (seal surface), and the O-

rings

23 and 24 provide a shaft hole 53 b of the fixed ring 21 and the front housing 53. Is sealed. Here, the O-ring 23 arranged in the housing (refrigerant side) direction is superior in foam resistance to the O-ring 24 arranged in the housing outside (atmosphere side) direction. Further, the O-ring 24 arranged in the outer direction of the housing is superior in permeation resistance than the O-ring 23 arranged in the inner direction of the housing. Specifically, the O-ring 23 is made of silicon rubber having excellent foam resistance, and the O-ring 24 is made of fluorine rubber or nitrile rubber having excellent permeation resistance.

In such a compressor, the fixed-side seal end surface 21a and the rotary-side seal end surface 22a slide, and frictional heat is generated in the sliding portion. In addition, when carbon dioxide is employed as the refrigerant for the compressor, the ambient temperature of the shaft seal device becomes higher than that when chlorofluorocarbon is used. Therefore, the O-ring used in such a shaft seal device is also required to have excellent heat resistance.

Here, the characteristics of various rubber materials in the usage environment of carbon dioxide refrigerant will be described. FIG. 3 is a diagram comparing the characteristics of various rubber materials in the environment where carbon dioxide refrigerant is used.

Here, the heat resistance is evaluated by the time during which the O-ring can function as a rubber having elasticity when the O-ring having a predetermined shape is left in an environment of 150 ° C. The heat resistance becomes higher as the time that can function as a rubber having elasticity is longer.

Moreover, the carbon dioxide permeation resistance is evaluated by the gas permeability of carbon dioxide. The carbon dioxide permeation resistance is evaluated by gas permeability at a pressure difference of 5 MPa of carbon dioxide. The carbon dioxide permeation resistance becomes higher as the gas permeability of carbon dioxide is lower.

In addition, the foaming resistance is determined by immersing an O-ring of a predetermined shape in liquefied carbon dioxide at 20 ° C. for 15 hours, then immediately releasing it into the atmosphere and leaving it in a high-temperature atmosphere at 100 ° C. for 1 hour. It was evaluated by the number of visible cracks confirmed on each cut surface when divided at a place. The foaming resistance becomes higher as the number of cracks is smaller.

EPDM (ethylene propylene rubber) has normal heat resistance but is inferior in carbon dioxide permeation resistance and foam resistance. HNBR (nitrile rubber) is excellent in carbon dioxide permeation resistance but inferior in heat resistance and foam resistance. Moreover, CR (chloroprene rubber) has ordinary carbon dioxide permeation resistance but is inferior in heat resistance and foam resistance. ACM (acrylic rubber) has normal heat resistance but is inferior in carbon dioxide permeation resistance and foam resistance. VQM (silicone rubber) is excellent in heat resistance and foam resistance but inferior in carbon dioxide permeation resistance. Moreover, FKM (fluoro rubber) is excellent in heat resistance and carbon dioxide permeation resistance, but inferior in foam resistance.

In the shaft seal device 20, the O-ring 25 arranged in the direction of the refrigerant inside the housing is made of silicon rubber having excellent foam resistance. Therefore, the foaming phenomenon in which the carbon dioxide refrigerant permeates into the O-ring 25 due to pressure fluctuation and cracks are generated is suppressed.

Moreover, since the O-ring 25 is made of silicon rubber and has poor permeation resistance, the refrigerant permeates. For this reason, an O-ring 26 made of fluorine rubber or nitrile rubber having excellent permeation resistance is disposed in the atmosphere side direction outside the housing with respect to the O-ring 25. The O-ring 26 may be disposed closer to the atmosphere outside the housing than the O-ring 25.

Although the O-ring 26 is inferior in foaming resistance, the O-ring 25 made of silicon rubber having excellent foaming resistance is arranged in the refrigerant side direction inside the housing relative to the O-ring 26, so that the pressure is reduced. The effects of fluctuations are also suppressed. The O-ring 25 may be disposed closer to the refrigerant inside the housing than the O-ring 26.

According to the configuration described above, a plurality of O-rings 23 to 26 are provided between the housing and the stationary ring 21 and between the shaft 63 and the rotating ring 22 so as to be aligned in the axial direction of the shaft 63. Among the plurality of O-rings arranged in the axial direction, O-

rings

23 and 25 arranged in the refrigerant side direction inside the housing are O-

rings

24 and 26 arranged in the atmosphere side direction outside the housing. Therefore, the O-

rings

23 and 25 can satisfy the requirements for foam resistance. Further, since the O-

rings

24 and 26 arranged in the atmosphere side direction outside the housing have better permeation resistance than the O-

rings

23 and 25 arranged in the refrigerant side direction inside the housing, these O-

rings

24 and 26 can satisfy the requirement of permeation resistance. Thus, the two requirements of foaming resistance and permeation resistance can be satisfied, and the sealing performance of the sealing surface can be maintained for a longer period. At least one of a plurality of O-

rings

23 and 24 that seal between the housing and the stationary ring 21 and a plurality of O-

rings

25 and 26 that seal between the shaft 63 and the rotating ring 22 may be provided. .

In addition, between the shaft 63 and the rotating ring 22 (seal surface), the rotating 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 above-described O-rings 23 to 26 between the rings 22 (seal surface), it is possible to effectively seal.

In addition, the O-

rings

23 and 25 arranged in the inner direction of the housing are made of silicon rubber, and the O-

rings

24 and 26 arranged in the outer direction of the housing are made of fluorine rubber or nitrile rubber, thereby being heat resistant. Three requirements of resistance, foam resistance and permeation resistance can be satisfied, and the sealing performance of the sealing surface can be maintained for a longer period of time.

(Second Embodiment)
Hereinafter, the compressor and the shaft seal device according to the second embodiment of the present disclosure will be described with reference to FIG. 4. In the compressor according to the first embodiment, the

groove portions

210 and 211 are separately formed on the outer peripheral surface of the stationary ring 21, and the

groove portions

220 and 221 are separately formed on the inner peripheral surface of the rotating ring 22. O-rings 23 to 26 are disposed at 210, 211, 220, and 221 respectively. On the other hand, in the compressor according to this embodiment, one groove portion 212 is formed on the outer peripheral surface of the stationary ring 21, and the O-

rings

23 and 24 are disposed in the groove portion 212. One groove portion 222 is formed on the inner peripheral surface of the rotating ring 22, and O-

rings

25 and 26 are disposed in the groove portion 222.

As described above, the O-

rings

23 and 24 may be disposed in one groove 212 and the O-

rings

25 and 26 may be disposed in one groove 222.

In this embodiment, the effect produced from the configuration of the first embodiment can be obtained as in the first embodiment.

In the first and second embodiments, the two O rings 23 and 24 are provided between the stationary ring 21 and the front housing 53 (for example, the contact surface), but three or more O rings may be provided. In the first and second embodiments, the two O-

rings

25 and 26 are provided between the rotating ring 22 and the shaft 63 (for example, the contact surface), but three or more O-rings may be provided. .

In the first and second embodiments, the O-rings 23 to 26 are provided between the fixed ring 21 and the front housing 53, and between the rotary ring 22 and the shaft 63. However, the fixed ring 21 and the front housing 53 are provided. Each O-ring may be provided between the rotary ring 22 and the rotary ring 22 and the shaft 63.

In the first and second embodiments, the two O-

rings

23 and 24 are provided between the fixed ring 21 and the front housing 53. However, a plurality of O-rings are provided between the fixed ring 21 and the front housing 53. It may be provided. In the first and second embodiments, a plurality of O-

rings

25 and 26 are provided between the rotating ring 22 and the shaft 63, but a plurality of O-rings are provided between the rotating ring 22 and the shaft 63. Also good.

In the first and second embodiments, an example is shown in which the present invention is applied to a compressor that compresses a carbon dioxide refrigerant, but the present invention can also be applied to a compressor that compresses a fluid other than carbon dioxide.

In the first and second embodiments, the balance-type shaft seal device has been described as an example. However, the present invention is not limited to such a type of shaft seal device, and is applied to, for example, an unbalanced shaft seal device. You can also.

In the first and second embodiments, the O-rings 23 to 26 are provided on both the sealing surfaces of the housing 53 and the stationary ring 21 and the sealing surfaces of the shaft 63 and the rotating ring 22. An O-ring may be provided on at least one of the seal surface of the ring 21 and the seal surface of the shaft 63 and the rotary ring 22. Further, O-

rings

25 and 26 may be provided on the seal surfaces of the shaft 63 and the rotating ring 22, and for example, the seal surfaces of the housing 53 and the fixed ring 21 may be joined so that the sealing performance is maintained.

Note that the present disclosure is not limited to the above-described embodiment, and can be changed as appropriate. 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.

Although the present disclosure has been described based on the embodiments, it is understood that the present disclosure is not limited to the embodiments and structures. The present disclosure includes various modifications and modifications within the equivalent range. In addition, various combinations and forms, as well as other combinations and forms including only one element, more or less, are within the scope and spirit of the present disclosure.

Claims

A shaft seal device (20) for a compressor (51) for compressing 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 formed in the housing and rotatably supporting the shaft inserted through the shaft hole;
A plurality of O-rings (23 to 26) for sealing at least one of the housing and the stationary ring and between the shaft and the rotating ring are provided so as to be aligned in the axial direction of the shaft,
Among the plurality of O-rings, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing, and the housing A shaft seal device in which the O-ring arranged on the atmosphere side outside the tube is superior in permeation resistance than the O-ring arranged on the refrigerant side inside the housing.
The shaft seal device according to claim 1, wherein the plurality of O-rings are provided so as to seal between the shaft and the rotating ring.
2. The O-ring arranged on the refrigerant side inside the housing is made of silicon rubber, and the O-ring arranged on the atmosphere side outside the housing is made of fluorine rubber. Or the shaft seal apparatus of 2.
A shaft seal device according to any one of claims 1 to 3, comprising:
The shaft seal device is a compressor that seals the periphery of the shaft.
A shaft seal device (20) for a compressor (51) for compressing 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 formed in the housing and rotatably supporting the shaft inserted through the shaft hole;
At least one of a plurality of O-rings (23, 24) for sealing between the housing and the stationary ring and a plurality of O-rings (25, 26) for sealing between the shaft and the rotating ring is provided. Provided,
Among the plurality of O-rings, the O-ring arranged on the refrigerant side inside the housing has better foam resistance than the O-ring arranged on the atmosphere side outside the housing, and the housing A shaft seal device in which the O-ring arranged on the atmosphere side outside the tube is superior in permeation resistance than the O-ring arranged on the refrigerant side inside the housing.
The shaft seal device according to claim 5, wherein a plurality of O-rings for sealing between the shaft and the rotating ring are provided.
The O-ring arranged on the refrigerant side inside the housing is made of silicon rubber, and the O-ring arranged on the atmosphere side outside the housing is made of fluorine rubber or nitrile rubber. The shaft seal device according to claim 5 or 6.