US20060162546A1 - Sealing member of a compressor - Google Patents

Abstract

A coat of material impermeable to coolant gas is formed on the surface of a sealing member of a compressor for absorbing and compressing the coolant gas.

Description

BACKGROUND OF THE INVENTION
• The present invention relates to a sealing member of a compressor for absorbing and compressing coolant gas.
• Japanese Patent Laid-Open Publication No. 2003-246976 discloses a sealing member of a carbon dioxide compressor excellent in impermeability to carbon dioxide.
• The prior art disclosed in Japanese Patent Laid-Open Publication No. 2003-246976 provides a sealing member of a compressor suitable for use with a specific coolant gas and does not provide a sealing member of a compressor suitable for use with various kinds of coolant gases.
SUMMARY OF THE INVENTION
• An object of the present invention is to provide a sealing member of a compressor suitable for use with various kinds of coolant gases.
• In accordance with the present invention, there is provided a sealing member of a compressor for absorbing and compressing coolant gas, wherein a coat of material impermeable to coolant gas is formed on the surface of the sealing member.
• A sealing member provided with a coat of material impermeable to coolant gas formed on the surface thereof, can be used in compressors for various kinds of coolant gases.
• A coat of soft metal, ceramic, amorphous hard carbon or high polymer material such as polyethylene, polytetrafluoroethylene, or the like is highly impermeable to any kind of coolant gas. Each of the materials has a specific character. Therefore, the most suitable material is desired to be used for the coat considering the working environment of the compressor, working environment of the sealing member, etc.
• In accordance with another aspect of the present invention, there is provided a compressor for absorbing and compressing coolant gas comprising a sealing member, wherein a coat of material impermeable to coolant gas is formed on the surface of the sealing member.
• When a coat of material impermeable to coolant gas is formed on the surface of the sealing member, impermeability of the sealing member is enhanced to any kind of coolant gas. Therefore, the compressor of the present invention can effectively prevent leakage of coolant gas. The compressor of the present invention can compress various kinds of coolant gases, while effectively preventing leakage of coolant gas.
• A coat of soft metal, ceramic, amorphous hard carbon or high polymer material such as polyethylene, polytetrafluoroethylene, or the like is highly impermeable to any kind of coolant gas. Each of the materials has a specific character. Therefore, the most suitable material is desirably used for the coat considering the working environment of the compressor, working environment of the sealing member, etc.
• In accordance with a preferred embodiment of the present invention, the compressor further comprises a rotating shaft, a compressing mechanism driven by the rotating shaft, a housing for accommodating the rotating shaft and the compressing mechanism, and a shaft seal member. The sealing member is the shaft seal member.
• In accordance with a preferred embodiment of the present invention, the compressor further comprises a rotating shaft, a compressing mechanism driven by the rotating shaft, and a housing for accommodating the rotating shaft and the compressing mechanism. The housing is an assembly of a plurality of partial housings. Gaskets are inserted into joints of the partial housings, and the sealing member is one of the gaskets.
• The sealing member is suitably used as a shaft seal member, a gasket, etc.
BRIEF DESCRIPTION OF THE DRAWINGS
• In the drawings:
• FIG. 1 is a sectional view of a variable delivery swash plate compressor provided with a sealing member in accordance with a preferred embodiment of the present invention.
• FIG. 2 is a fragmentary sectional view of a variable delivery swash plate compressor provided with a sealing member in accordance with a preferred embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
• A variable delivery swash plate compressor provided with a sealing member in accordance with a preferred embodiment of the present invention will be described.
• As shown inFIG. 1, a variable delivery swash plate compressor A is provided with arotating shaft10, arotor11 fixed to the rotatingshaft10 and aswash plate12 supported by therotating shaft10 to be variable in inclination relative to the rotatingshaft10. Theswash plate12 is connected to therotor11 through alinkage13 for allowing theswash plate12 to vary in inclination relative to the rotatingshaft10 and inhibiting theswash plate12 from rotating around the rotatingshaft10. Theswash plate12 rotates synchronously with therotor11 and the rotatingshaft10.
• A plurality ofpistons15 engage theswash plate12 through a plurality of pairs ofshoes14 slidingly engaging the peripheral portion of theswash plate12. Thepistons15 are inserted incylinder bores16aformed in acylinder block16.
• Afront housing18 of circular cylindrical shape forms acrank chamber17 for accommodating the rotatingshaft10, therotor11 and theswash plate12. Thefront housing18 is closed at one end and provided with a boss18aat the closed end. The rotatingshaft10 passes through the boss18aout of thefront housing18 at the front end. An annular space is formed between the rotatingshaft10 and the inner circumferential surface of the boss18a.
• Ashaft seal19 is disposed to seal the annular space between the rotatingshaft10 and the inner circumferential surface of the boss18a. As shown inFIG. 2, theshaft seal19 is provided withlip seal members19aand19bslidingly contacting the circumferential side surface of the rotatingshaft10 and clampingmetals19cand19dfor clamping and fixing thelip seals19aand19b. Thelip seal19adisposed close to thecrank chamber17 is a rubber molding made mainly of hydro-nitrile rubber (HNBR) and is covered by a coat of soft metal such as tin (Sn), alloy metal containing copper (Cu) and tin (Sn), alloy metal containing nickel (Ni) and tin (Sn), alloy metal containing zinc (Zn) and tin (Sn), or the like. Thelip seal19ais provided with a fixedportion19a′ clamped by theclamping metals19cand19dand amovable portion19a″ slidingly contacting the circumferential side surface of the rotatingshaft10. Thelip seal19bdisposed close to one end of the rotatingshaft10 projecting from thefront housing18 is made of a synthetic resin such as polytetrafluoroethylene (PTFE). Thelip seal19bis provided with a fixedportion19b′ clamped by theclamping metals19cand19dand amovable portion19b″ slidingly contacting the circumferential side surface of the rotatingshaft10. Before theshaft seal19 is assembled with the boss18a, themovable portions19a″ and19b″ extend inwardly in radial direction as indicated by phantom lines inFIG. 2. After theshaft seal19 has been assembled with the boss18a, themovable portions19a″ and19b″ are forced against the circumferential side surface of the rotatingshaft10 to slidingly contact the circumferential side surface, thereby sealing the annular space between the rotatingshaft10 and the inner circumferential surface of the boss18a.
• As shown inFIG. 1, anelectromagnetic clutch20 mounted on the boss18aof thefront housing18 transfers rotating force from external power source not shown in the figures to the front end of the rotatingshaft10.
• Acylinder head21 forming aninlet chamber21aand anoutlet chamber21bis installed.
• Avalve plate22 provided withinlet holes22aandoutlet holes22bis disposed between thecylinder block16 and thecylinder head21. Theinlet holes22aand theoutlet holes22bcommunicate with thecylinder bores16a.
• Thefront housing18, thecylinder block16, thevalve plate22 and thecylinder head21 are assembled in a unit bybolts23.
• Agasket24 is inserted into the joint between thefront housing18 and thecylinder block16. Agasket25 is inserted into the joint between thecylinder block16 and thevalve plate22. Agasket26 is inserted into the joint between thevalve plate22 and thecylinder head21. Thegaskets24,25 and26 seal the aforementioned joints.
• Thegaskets24,25 and26 are rubber moldings made mainly of hydro-nitrile rubber (HNBR) or nitrile rubber (NBR). Each of them is covered by a coat of soft metal such as tin (Sn), alloy metal containing copper (Cu) and tin (Sn), alloy metal containing nickel (Ni) and tin (Sn), alloy metal containing zinc (Zn) and tin (Sn), or the like.
• The rotatingshaft10 is rotatably supported by thefront housing18 and thecylinder block16.
• Therotor11, thelinkage13, theswash plate12, theshoes14 and thepistons15 form a compressing mechanism.
• The operation of the variable delivery swash plate compressor A in accordance with the present preferred embodiment will be described.
• Rotating force is transferred to the rotatingshaft10 from the external power source not shown in the figures through theelectromagnetic clutch20, and rotation of the rotatingshaft10 is transferred to theswash plate12 through therotor11 and thelinkage13. The rotation of theswash plate12 causes reciprocal movement of the peripheral portion of theswash plate12 in the longitudinal direction of therotating shaft10. The reciprocal movement of the peripheral portion of theswash plate12 is transferred to thepiston15 through theshoes14, and thepiston15 moves reciprocally in the cylinder bore16a. Coolant gas enters into theinlet chamber21afrom an external coolant circuit through an inlet port following the reciprocal movement of thepiston15. The coolant gas is sucked into the cylinder bores16athrough the inlet holes22aand inlet valves not shown in the figures to be pressurized in the cylinder bores16a. The pressurized coolant gas in the cylinder bores16adischarges into theoutlet chamber21bthrough the outlet holes22band outlet valves not shown in the figures, and then discharges from theoutlet chamber21binto the external coolant circuit through an outlet port.
• Theshaft seal19 and thegaskets24 to26 prevent leakage of the coolant gas from the variable delivery swash plate compressor A.
• A coat of soft metal is formed on each of thelip seal19aand thegaskets24 to26. Therefore, they are highly impermeable to various kinds of coolant gases, such as Freon, carbon hydride, alternative Freon, carbon dioxide, ammonia, etc. Therefore, whatever kind of coolant gas is compressed by the variable delivery swash plate compressor A, leakage of the coolant gas from the variable delivery swash plate compressor A is reliably prevented. Hydro-nitrile rubber is easy to obtain because it is used as the material of sealing members of coolant gas compressors. The soft metal is suitable for use on sliding contact parts because it reduces friction resistance.
• A coat of ceramic such as silicon carbide (SiC), alumina (Al₂O₃), silicon nitride (Si₃N₄), zirconia (ZrO₂), etc., amorphous hard carbon (DLC), or high polymer material such as polyethylene, polytetrafluoroethylene, etc. may be formed on the surface of thelip seal19aand thegaskets24 to26. The impermeability of the aforementioned seal members to the various coolant gases is enhanced and the ability of the coolant gas compressor to prevent leakage of coolant gas is enhanced.
• Ceramic has advantages such as low apparent density, low thermal expansion coefficient, high hardness, high corrosion resistance, non-magnetism, high insulation performance, etc. Especially, silicon nitride has large flexural strength at high temperature and is suitable for use on bearings. Silicon carbide has advantages such as high hardness, large thermal conductivity, high resistance against thermal shock, etc. and is suitable for use on the shaft seal.
• Amorphous hard carbon has advantages such as high hardness, low friction coefficient, high ware resistance, high sliding ability, etc. Film thickness and surface roughness can be easily controlled when amorphous hard carbon is coated on the surface of a seal member. Therefore, finishing becomes unnecessary and coating cost decreases.
• Polyethylene has advantages such as high thermal stability, high chemical resistance, inexpensiveness, etc. Polytetrafluoroethylene has an advantage in that it decreases friction resistance and is suitable for use on sliding contact parts.
• The most suitable material is desirably used for the coat formed on the surface of a seal member considering the working environment of the compressor, working environment of the sealing member, etc.
• The present invention can be used for sealing members of any kind of coolant gas compressor.
• While the present invention has been described with reference to preferred embodiments, one of ordinary skill in the art will recognize that modifications and improvements may be made while remaining within the spirit and scope of the present invention. The scope of the invention is determined solely by the attached claims.

Claims (16)

1. A sealing member of a compressor for absorbing and compressing coolant gas, wherein a coat of material impermeable to coolant gas is formed on the surface of the sealing member.

2. A sealing member ofclaim 1, wherein the material of the coat is soft metal.

3. A sealing member ofclaim 1, wherein the material of the coat is ceramic.

4. A sealing member ofclaim 1, wherein the material of the coat is amorphous hard carbon.

5. A sealing member ofclaim 1, wherein the material of the coat is high polymer material.

6. A sealing member ofclaim 5, wherein the high polymer material is polyethylene.

7. A sealing member ofclaim 5, wherein the high polymer material is polytetrafluoroethylene.

8. A compressor for absorbing and compressing coolant gas comprising a sealing member, wherein a coat of material impermeable to coolant gas is formed on the surface of the sealing member.

9. A compressor ofclaim 8, wherein the material of the coat is soft metal.

10. A compressor ofclaim 8, wherein the material of the coat is ceramic.

11. A compressor ofclaim 8, wherein the material of the coat is amorphous hard carbon.

12. A compressor ofclaim 8, wherein the material of the coat is high polymer material.

13. A compressor ofclaim 12, wherein the high polymer material is polyethylene.

14. A compressor ofclaim 12, wherein the high polymer material is polytetrafluoroethylene.

15. A compressor ofclaim 8 further comprising a rotating shaft, a compressing mechanism driven by the rotating shaft, a housing for accommodating the rotating shaft and the compressing mechanism, and a shaft seal member, wherein the sealing member is the shaft seal member.

16. A compressor ofclaim 8 further comprising a rotating shaft, a compressing mechanism driven by the rotating shaft, and a housing for accommodating the rotating shaft and the compressing mechanism, wherein the housing is an assembly of a plurality of partial housings, gaskets are inserted into joints of the partial housings, and the sealing member is one of the gaskets.

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