JP2009108688A - Shaft sealing device for compressor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a shaft sealing device for a compressor capable of securely preventing leakage of oil at an initial stage of operation before starting of control operation and having excellent reliability. <P>SOLUTION: The shaft sealing device for the compressor uses a mechanical seal comprising a mating ring positioned around a rotating shaft of the compressor and fixed to a housing side and a seal ring rotated together with the rotating shaft, having a side face slidably abutting on the side face of the mating ring and forming a seal part between the mating ring and the seal ring. In the shaft sealing device for the compressor, an oil seal member having a function to seal oil between axial both sides of the mating ring is fitted between the inner peripheral face of the mating ring and the outer peripheral face of the rotating shaft. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a shaft seal device for a compressor used in, for example, a refrigeration system for a vehicle air conditioner.

  A shaft seal device for sealing the inside and outside of the compressor is generally provided around the rotation shaft of the compressor. As a shaft seal device, a shaft seal device having a mechanical seal structure as shown in FIG. 7 is known. In FIG. 7, reference numeral 100 denotes a rotating shaft (shaft) of the compressor, and a shaft seal device 101 is provided around the rotating shaft 100. The shaft seal device 101 includes a seal ring 102 and a mating ring 103. The seal ring 102 is configured to be rotatable together with the rotating shaft 100. The seal ring 102 is urged toward the mating ring by a spring 104, and the side surface 102 a of the seal ring 102 is in sliding contact with the side surface 103 a of the mating ring 103 fixed to the housing 105. A seal structure that prevents leakage of the sealed fluid (for example, refrigerant) is formed by the oil film on the sliding contact surface.

  Such a shaft seal device having a mechanical seal structure can significantly reduce leakage of fluid and oil (lubricating oil), reduce power loss, and generate less heat. In addition, it has excellent properties such as low wear of sliding parts, excellent durability, and use under high temperature and high pressure environments.

  However, particularly when the shaft seal device is new or when the device has been stopped for a long period of time, since the familiarity between the side surface 102a and the side surface 103a has not progressed, oil film formation is not possible. There is a risk that oil (lubricating oil) and the enclosed fluid may leak to the outside of the compressor through a path as indicated by an arrow in FIG. In particular, during the operation of the refrigeration system, since the maximum internal pressure of the compressor is applied before the system control is started (for example, before the inclination angle of the swash plate is changed in a swash plate compressor), the control operation is started Oil is likely to leak out of the system during the initial phase of the previous run.

In order to solve such a problem, for example, proposals have been made regarding a damming structure that prevents oil leakage (for example, Patent Documents 1 and 2), but it is sufficient to prevent oil leakage at the initial stage of operation. It's hard to say. Moreover, in these proposals, the structure may be complicated.
JP-A-7-145780 JP 2000-136770 A

  Therefore, an object of the present invention is to provide a shaft seal device for a compressor that can reliably prevent oil leakage particularly in the initial stage of operation before the start of control operation and has excellent reliability.

  In order to solve the above-described problems, a shaft seal device for a compressor according to the present invention includes a mating ring fixed to a housing around a rotating shaft of the compressor, and the mating ring and side surfaces that rotate together with the rotating shaft. In a shaft seal device of a compressor using a mechanical seal comprising a seal ring that is slidably contacted with each other to form a seal portion between both rings, the inner peripheral surface of the mating ring and the rotary shaft An oil seal member having a function of sealing oil between both sides in the axial direction of the mating ring is mounted between the outer peripheral surface and the outer peripheral surface. In such a configuration, since an oil seal member having a function of sealing oil between both sides in the axial direction of the mating ring is mounted, oil leakage to the outside of the compressor can be reliably prevented. . In addition, by securely sealing the oil between both sides of the mating ring in the axial direction, an oil reservoir is formed in the portion, so that it is possible to contribute to prevention of fluid leakage by the sealing effect of the oil reservoir.

  The compressor according to the present invention is suitable for a compressor of a vehicle air conditioner, for example, but in such a refrigeration system, before the system control is started (for example, swash plate compression) In the machine, the maximum internal pressure of the compressor is applied inside the compressor before changing the inclination angle of the swash plate. For this reason, it becomes easy for oil to leak in the initial stage of the operation before starting the control operation. Therefore, the oil seal member is mated when a differential pressure is generated between the external pressure outside the compressor on the other axial side of the mating ring when the maximum internal pressure of the compressor is applied to one side of the mating ring in the axial direction. A member having a function of sealing oil between both axial sides of the ring is preferable. According to such a configuration, it is possible to effectively prevent oil leakage particularly in the initial stage of the operation before the start of the control operation.

  The oil seal member is a seal member held on the inner peripheral surface side of the mating ring so as to be slidable on the outer peripheral surface of the rotating shaft, for example, any of an O-ring, a square ring, a cylindrical seal, and a lip seal. Can be formed.

  In the shaft seal device for a compressor according to the present invention, oil leakage from the inside of the compressor can be reliably prevented, and oil leakage can be effectively prevented particularly at the initial stage of operation before the start of system control.

  The oil seal member can be formed of, for example, an O-ring, a square ring, a cylindrical seal, or a lip seal, and can be easily applied to existing compressors simply by making improvements. can do.

Preferred embodiments of a shaft seal device for a compressor according to the present invention will be described below with reference to the drawings.
1 to 3 show a shaft seal device for a compressor according to a first embodiment of the present invention. 1, reference numeral 1 denotes a compressor. In the following embodiments, the compressor is configured as a compressor applied to a refrigeration cycle of a vehicle air conditioner. The compressor 1 has a housing 2, and a rotating shaft 4 is rotatably supported on the housing 2 via bearings 3a and 3b. A shaft seal device 5 is provided around the rotation shaft 4. The shaft seal device 5 includes a mating ring 6 fixed to the housing side and a seal ring 7 that rotates together with the rotary shaft 4. The seal ring 7 is configured to be movable in the axial direction of the rotary shaft 4 and is biased toward the mating ring 6 by a spring 20 in this embodiment. The side surface 9 of the seal ring 7 is in sliding contact with the side surface 8 of the mating ring 6.

  Between the inner peripheral surface 10 of the mating ring 6 and the outer peripheral surface 11 of the rotating shaft 4, an O-ring 12 as an oil seal member having a function of sealing oil between both axial sides of the mating ring 6. Is provided. The O-ring 12 is mounted in a groove 13 provided on the inner peripheral surface 10 of the mating ring 6 and is in contact with the outer peripheral surface 11 of the rotating shaft 4. An O-ring 16 that contacts the inner peripheral surface of the housing 2 is attached to the groove 15 provided on the outer peripheral surface 14 of the mating ring 6.

  The O-ring 12 is the other side in the axial direction of the mating ring 6 when the highest internal pressure of the compressor is applied to one side of the mating ring 6 in the axial direction (the right side of the mating ring 6 in FIG. 1). 1 is configured as a member having a function of sealing oil between both sides of the mating ring 6 in the axial direction when a pressure difference between the atmospheric pressure outside the compressor on the left side of the mating ring 6 occurs.

  In this embodiment, since the O-ring 12 is mounted as an oil seal member having a function of sealing oil between both sides of the iting ring 6 in the axial direction, oil leakage to the outside of the compressor is surely prevented. can do. In addition, by securely sealing the oil between both sides of the mating ring 6 in the axial direction, an oil reservoir is formed upstream of the O-ring 12, which contributes to prevention of fluid leakage due to the sealing effect of the oil reservoir. can do. Further, the O-ring 12 is the other side in the axial direction of the mating ring 6 when the compressor internal maximum pressure is applied to one side of the mating ring 6 in the axial direction (the right side of the mating ring 6 in FIG. 1). When the pressure difference between the atmospheric pressure outside the compressor (on the left side of the mating ring 6 in FIG. 1) is generated, the member is configured as a member having a function of sealing oil between both sides of the mating ring 6 in the axial direction. . Therefore, when the oil is likely to leak, that is, before the system control is started (for example, before the inclination angle of the swash plate is changed in a swash plate compressor), the maximum internal pressure of the compressor is applied. Oil leakage at the time can be reliably prevented. On the other hand, when the initial stage of operation has passed and the side surface 8 and the side surface 9 have become familiar, oil and fluid leakage is reliably prevented by the sealing surface formed between the side surface 8 and the side surface 9. In this case, there is no problem even if the O-ring 12 and the outer peripheral surface 11 of the rotary shaft 4 are not in contact with each other.

  FIG. 4 shows a shaft seal device for a compressor according to a second embodiment of the present invention. In the following embodiments, the same members as those in the first embodiment are denoted by the same reference numerals and description thereof is omitted. In the present embodiment, a square ring 17 is provided as an oil seal member having a function of sealing oil between both axial sides of the mating ring 6. The square ring 17 has a square cross-sectional shape and is mounted in the groove 13 of the mating ring 6.

  FIG. 5 shows a shaft seal device for a compressor according to a third embodiment of the present invention. In the present embodiment, a cylindrical seal 18 is provided on the inner peripheral surface 10 of the mating ring 6 as an oil seal member having a function of sealing oil between both axial sides of the mating ring 6. The cylindrical seal 18 is fixed to the inner peripheral surface 10 of the mating ring 6 by adhesion or the like.

  FIG. 6 shows a shaft seal device for a compressor according to a fourth embodiment of the present invention. In this embodiment, a lip seal 19 is provided as an oil seal member having a function of sealing oil between both axial sides of the mating ring 6. The lip seal 19 is mounted in the groove 13 of the mating ring 6.

  In the second to fourth embodiments, since the oil seal member having the function of sealing the oil between both axial sides of the iting ring 6 is mounted, oil leakage to the outside of the compressor is surely prevented. can do. In addition, since oil is securely sealed between both sides of the mating ring 6 in the axial direction, an oil reservoir is formed upstream of the oil seal member, so that fluid leakage is effectively prevented by the oil reservoir seal. be able to. Further, the oil seal member is arranged in the axial direction of the mating ring 6 when the maximum internal pressure of the compressor is applied to one axial side of the mating ring 6 (the right side of the mating ring 6 in FIGS. 4 to 6). A member having a function of sealing oil between both sides in the axial direction of the mating ring 6 when a differential pressure with the atmospheric pressure outside the compressor on the other side (the left side of the mating ring 6 in FIGS. 4 to 6) is generated. It is configured as. Therefore, when the oil easily leaks, that is, before the system control is started (for example, before changing the inclination angle of the swash plate in a swash plate compressor), the maximum internal pressure of the compressor is applied. Oil leakage at the time can be reliably prevented.

  The compressor shaft seal device according to the present invention can be applied to a compressor used in various fields, and is particularly suitable as a shaft seal device for a compressor used in a refrigeration system for a vehicle air conditioner.

It is a fragmentary longitudinal cross-sectional view of a compressor provided with the shaft seal device according to the first embodiment of the present invention. It is an expanded sectional view of the shaft seal device of the compressor of FIG. It is an enlarged view of the A section of FIG. It is a partial expanded sectional view of the shaft seal device of the compressor concerning the 2nd embodiment of the present invention. It is a partial expanded sectional view of the shaft seal device of the compressor concerning the 3rd embodiment of the present invention. It is a partial expanded sectional view of the shaft seal device of the compressor concerning the 4th embodiment of the present invention. It is an expanded sectional view of the conventional shaft seal device of a compressor.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Compressor 2 Housing 3 Bearing 4 Rotating shaft 5 Shaft seal device 6 Mating ring 7 Seal ring 8 Side surface of mating ring 9 Side surface of sealing ring 10 Inner peripheral surface of mating ring 11 Outer peripheral surface of rotating shaft 12 Oil seal member O-ring 13 as groove 14 outer peripheral surface of mating ring 15 groove 16 O-ring 17 square ring as oil seal member 18 cylindrical ring as oil seal member 19 oil lip seal as seal member 20 spring

Claims (3)

  A mating ring fixed on the housing side around the rotating shaft of the compressor, and a seal that rotates together with the rotating shaft and that is slidably contacted with the mating ring to form a seal portion between the rings. In a shaft seal device of a compressor using a mechanical seal composed of a ring, between the inner peripheral surface of the mating ring and the outer peripheral surface of the rotary shaft, oil is sealed against both sides in the axial direction of the mating ring. A shaft seal device for a compressor, comprising an oil seal member having a function of   When the differential pressure between the oil seal member and the atmospheric pressure outside the compressor on the other side in the axial direction of the mating ring occurs when the highest pressure inside the compressor is applied to one side in the axial direction of the mating ring, the mating ring The shaft sealing device for a compressor according to claim 1, comprising a member having a function of sealing oil between both axial sides of the compressor. The oil seal member is formed of any one of an O-ring, a square ring, a cylindrical seal, and a lip seal that are slidably held on the outer peripheral surface of the rotating shaft on the inner peripheral surface side of the mating ring. A shaft seal device for a compressor according to claim 1 or 2.

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