JP2007218302A - Lip seal - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lip seal capable of reducing the leakage of a refrigerant during switching a rotating shaft between rotating and stopping states without causing a great cost increase or a structure change. <P>SOLUTION: The lip seal as a member for sealing the peripheral portion of the rotating shaft of a compressor, e.g., comprises a rubber lip provided on one axial side of a supporting ring, and a resin lip on the other side. A tip at the rotating shaft side of the rubber lip is formed thicker than a portion immediately before the tip, and/or a tip at the rotating shaft side of the resin lip is intentionally formed to extend so that the tip comes closer to the tip of the rubber lip. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a lip seal as a shaft seal member for a rotary shaft, and more particularly to a lip seal suitable for use in sealing a drive shaft of a compressor.

  As the shaft seal member for the rotary shaft, for example, a lip seal is frequently used as a shaft seal member that is provided around the drive shaft of the compressor and seals between the inside of the compressor and the outside of the compressor (outside). Various proposals have been made regarding this lip seal. For example, Patent Document 1 discloses that a spiral cut groove is formed on a rotation shaft contact surface of a lip seal portion that contacts an outer peripheral surface of a rotation drive shaft in a compressor, so that the high pressure portion side is accompanied by rotation of the rotation shaft. Disclosed is a technology for recirculating a refrigerant that is about to leak from a gap between a lip seal and a rotating shaft from a compressor internal side to a low pressure side (compressor external side) to a high pressure side by a screw pump action. Has been.

Further, Patent Document 2 discloses that a lip seal as a shaft seal member for a drive shaft of a compressor is subjected to surface treatment with a polymer film or a resin film that does not allow refrigerant to permeate on the surface of the seal material. A technique for reducing the amount of refrigerant leakage is disclosed.
Japanese Patent No. 2847277 JP 2005-155591 A

  However, the following problems remain in the prior art as described above. A conventional general lip seal is configured as shown in FIG. 6, for example. In FIG. 6, reference numeral 101 denotes a rotating shaft, and a lip seal 102 is disposed so as to seal the periphery of the rotating shaft 101. The lip seal 102 includes a rubber lip 104 on one side (for example, a compressor inner side) of a support ring 103 (for example, a metal ring) and a resin lip 105 on the other side. For example, the compressor inner side) can be sealed against the low-pressure resin lip arrangement side (for example, the compressor outer side).

  However, as described above, for example, the lip seal 102 for preventing the refrigerant leakage of the compressor is composed of the rubber lip 104 and the resin lip 105. However, the lip seal 102 depends on whether the compressor is operating or stopped. The main sealing part at is switched. That is, when the compressor is in operation, the sealing effect by the rubber lip 104 is low, and when the compressor is stopped (at rest), the sealing effect by the external resin lip 105 is low. Therefore, when the compressor is operated, the refrigerant easily passes through the rubber lip 104 portion and enters the space 106 between the rubber lip 104 and the resin lip 105. There is a phenomenon that leaks easily.

  For such a phenomenon, the technique described in Patent Document 1 is a refrigerant leakage prevention technique targeted at the compressor operating state, and the technique described in Patent Document 2 is targeted at the compressor stationary state. Thus, it is difficult to reduce refrigerant leakage at the time of switching between the operating state and the stationary state.

  Therefore, the problem of the present invention is to pay attention to such problems, and at the time of switching between the rotation and stop states of the rotating shaft (for example, the operation / stationary state of the compressor) without causing a significant increase in cost or a change in structure. It is an object of the present invention to provide a lip seal that can reduce leakage of refrigerant or the like at the time of switching.

  In order to solve the above problems, a lip seal according to the present invention is a member that seals the periphery of a rotating shaft, and is a lip seal provided with a rubber lip on one side in the axial direction of a support ring and a resin lip on the other side. The front end of the rubber lip on the rotating shaft side is formed thicker than the front end of the front end.

  The lip seal according to the present invention is a member that seals the periphery of the rotating shaft, and the lip seal includes a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. The shaft-side tip is intentionally or / and forcibly bent so that the tip is closer to the resin lip tip.

  The lip seal according to the present invention is a member that seals the periphery of the rotating shaft, and the lip seal includes a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. The tip portion on the rotating shaft side is formed to be thicker than the portion immediately before the tip portion.

  Furthermore, the lip seal according to the present invention is a member that seals the periphery of the rotating shaft, and the lip seal includes a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. The tip end portion on the rotating shaft side is intentionally extended so that the tip end portion is closer to the tip end side of the rubber lip.

  A lip seal provided with at least two of the configurations of the lip seal according to the present invention as described above is also included in the present invention.

  In such a lip seal according to the present invention, the support ring can be composed of, for example, a metal ring. Moreover, as resin of the said resin lip, a fluorine resin (for example, tetrafluoroethylene resin) can be used, for example.

  Moreover, the said rotating shaft consists of a drive shaft of a compressor, for example. A structure in which the resin lip is positioned on the inner side of the compressor and the rubber lip is positioned on the outer side of the compressor can be employed. As a compressor, it consists of what is used for a vehicle air conditioner, for example.

  According to the lip seal of the present invention, the rubber lip and / or the resin lip or both of them are thickened, or intentionally bent or extended so as to be closer to the other lip, compared with the conventional structure. The space between the rubber lip and the resin lip can be reduced, the amount of refrigerant entering the space through the rubber lip during operation of the compressor can be reduced, and the refrigerant leaking outside through the resin lip when stopped Etc. can be reduced.

  This reduction in the amount of refrigerant leakage can be achieved simply by forming the tip of the lip thicker or closer to the other lip, resulting in significant cost increases and structural changes. Can be achieved without.

Hereinafter, preferred embodiments of the present invention will be described with reference to the drawings.
FIG. 1 shows a lip seal 1 according to a first embodiment of the present invention, and shows an example applied to a drive shaft 2 as a rotating shaft of a compressor used in a vehicle air conditioner or the like. . The right side in FIG. 1 shows the inner side of the compressor, that is, the high-pressure side with the refrigerant compression operation, and the left side in FIG. 1 shows the outer side of the compressor, that is, the outside side. In the lip seal 1 according to the first embodiment, a rubber lip 4 is provided on one side (compressor internal side) of a support ring 3 made of a metal ring, and a resin lip 5 (for example, fluorine) is provided on the other side (compressor external side). A lip made of a base resin). And the front-end | tip part 4a by the side of the rotating shaft 2 of the rubber lip 4 is formed thicker than the front part of this front-end | tip part 4a. Due to this thick structure, the gap space 6 formed between the rubber lip 4 and the resin lip 5 is significantly reduced as compared with the conventional structure shown in FIG.

  In the lip seal 1 according to the first embodiment, the clearance space 6 between the rubber lip 4 and the resin lip 5 is reduced, so that the refrigerant intrusion amount through the rubber lip 4 portion during operation of the compressor is reduced. The amount of refrigerant leaking outside through the resin lip 5 from the gap space 6 when the compressor is stopped is reduced. Further, by making the tip portion 4a of the rubber lip 4 thick, it is possible to ensure a long refrigerant permeation distance between the rubber lip 4 and the rotating shaft 2, and the amount of refrigerant entering the gap space 6 through the rubber lip 4 portion. Will also be reduced. Therefore, comprehensively, the amount of refrigerant leakage is further reduced.

  FIG. 2 shows a lip seal 11 according to a second embodiment of the present invention. A rubber lip 14 is disposed on one side (compressor internal side) of the support ring 13 made of a metal ring, and a resin lip 15 (for example, a lip composed of a fluororesin) is disposed on the other side (compressor external side). In the lip seal 11 according to the second embodiment, the tip portion 14a of the rubber lip 14 on the rotating shaft 2 side is intentionally abruptly so that the tip portion 14a is closer to the tip portion side of the resin lip 15. It is bent and formed. In this case, for example, a cover 16 made of metal or the like is provided outside the tip portion 14a (inside the compressor), the tip portion 14a is forcibly bent so as to come closer to the tip portion side of the resin lip 15, and It is also possible to configure so that the folded state is maintained.

  Also in this second embodiment, the gap space 17 formed between the rubber lip 14 and the resin lip 15 is greatly reduced compared to the conventional structure shown in FIG. The amount of refrigerant entering through the rubber lip 14 portion is reduced, and the amount of refrigerant leaking outside through the resin lip 15 portion from the gap space 17 when the compressor is stopped is reduced.

  FIG. 3 shows a lip seal 21 according to a third embodiment of the present invention. A rubber lip 24 is disposed on one side (inside the compressor) of the support ring 23 made of a metal ring, and a resin lip 25 (for example, a lip composed of a fluorine-based resin) is disposed on the other side (outside the compressor). And in the lip seal 21 which concerns on this 3rd embodiment, the front-end | tip part 25a by the side of the rotating shaft 2 of the resin lip 25 is formed thicker than the front part of this front-end | tip part 25a. Due to this thick structure, the gap space 26 formed between the rubber lip 24 and the resin lip 25 is greatly reduced compared to the conventional structure shown in FIG. 6, and the rubber lip 24 during operation of the compressor is reduced. The amount of refrigerant entering through the portion is reduced, and the amount of refrigerant leaking outside through the resin lip 25 portion from the gap space 26 when the compressor is stopped is reduced.

  FIG. 4 shows a lip seal 31 according to a fourth embodiment of the present invention. A rubber lip 34 is disposed on one side (compressor internal side) of the support ring 33 made of a metal ring, and a resin lip 35 (for example, a lip composed of a fluororesin) is disposed on the other side (compressor external side). In the lip seal 31 according to the fourth embodiment, the tip 35a of the resin lip 35 on the rotating shaft 2 side is intentionally extended so that the tip 35a is closer to the tip of the rubber lip 34. Has been. With this extended structure, the gap space 36 formed between the rubber lip 34 and the resin lip 35 is greatly reduced compared to the conventional structure shown in FIG. Through the resin lip 35 is reduced from the gap space 36 when the compressor is stopped.

  The structure according to the present invention as described above can be adopted by combining at least two structures. For example, FIG. 5 shows a lip seal 41 according to a fifth embodiment of the present invention. In this embodiment, the structures according to the first embodiment and the fourth embodiment are substantially combined. A rubber lip 44 is disposed on one side (compressor internal side) of the support ring 43 made of a metal ring, and a resin lip 45 (for example, a lip composed of a fluororesin) is disposed on the other side (compressor external side). And in the lip seal 41 which concerns on this 5th embodiment, the front-end | tip part 44a by the side of the rotating shaft 2 of the rubber lip 44 is formed thicker than the front part of this front-end | tip part 44a. Further, the tip 45 a of the resin lip 45 on the rotating shaft 2 side is intentionally extended so that the tip 45 a is closer to the tip of the rubber lip 44. Due to the thick structure of the tip end portion 44a of the rubber lip 44 and the extension structure of the tip end portion 45a of the resin lip 45, a gap space 46 formed between the rubber lip 44 and the resin lip 45 as compared with the conventional structure shown in FIG. However, the amount of refrigerant entering through the rubber lip 44 during operation of the compressor is reduced, and the amount of refrigerant leaking outside from the gap space 46 through the resin lip 45 during operation of the compressor is reduced. Is done. At the same time, by thickening the tip end portion 44a of the rubber lip 44, a long refrigerant permeation distance can be secured between the rubber lip 44 and the rotating shaft 2, and the amount of refrigerant entering the gap space 46 through the rubber lip 44 portion. Will also be reduced. Therefore, comprehensively, the amount of refrigerant leakage is further reduced.

  Although each said embodiment demonstrated the example applied when using the lip seal which concerns on this invention as a shaft sealing member of the rotating shaft of a compressor, and reducing the leak amount of a refrigerant | coolant, the lip seal which concerns on this invention is However, the present invention is not limited to this, and can be applied to any device that is required to be used as a shaft seal member with respect to a rotating shaft.

It is a fragmentary longitudinal cross-sectional view of the lip seal which concerns on the 1st embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the lip seal which concerns on the 2nd embodiment of this invention. It is a partial longitudinal cross-sectional view of the lip seal which concerns on the 3rd embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the lip seal which concerns on the 4th embodiment of this invention. It is a fragmentary longitudinal cross-sectional view of the lip seal which concerns on the 5th embodiment of this invention. It is a partial longitudinal cross-sectional view of the conventional lip seal.

Explanation of symbols

1, 11, 21, 31, 41 Lip seal 2 Rotating shafts 3, 13, 23, 33, 43 Support rings 4, 14, 24, 34, 44 Rubber lips 4a, 14a, 44a Rubber lip tips 5, 15, 25, 35, 45 Resin lips 25a, 35a, 45a Resin lip end portions 6, 17, 26, 36, 46 Clearance space 16 Cover

Claims (10)

  A member that seals the periphery of the rotating shaft, and is a lip seal provided with a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. A lip seal characterized by being formed thicker than the immediately preceding portion.   A member that seals the periphery of the rotating shaft, and is a lip seal provided with a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. A lip seal that is intentionally or / and forcibly bent so as to be closer to the resin lip tip side.   A member that seals the periphery of the rotating shaft, and is a lip seal provided with a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. A lip seal characterized by being formed thicker than the portion immediately preceding the portion.   A member that seals the periphery of the rotating shaft, and is a lip seal provided with a rubber lip on one side in the axial direction of the support ring and a resin lip on the other side. A lip seal that is intentionally extended so that the portion is closer to the end of the rubber lip.   A lip seal comprising at least two of the configurations of the lip seal according to claim 1.   The lip seal according to any one of claims 1 to 5, wherein the support ring is made of a metal ring.   The lip seal according to any one of claims 1 to 6, wherein the resin of the resin lip is made of a fluorine resin.   The lip seal according to any one of claims 1 to 7, wherein the rotary shaft is a drive shaft of a compressor.   The lip seal according to claim 8, wherein the resin lip is located on the inner side of the compressor and the rubber lip is located on the outer side of the compressor.   The lip seal according to claim 8 or 9, wherein the compressor is used for a vehicle air conditioner.

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