Refrigerant compressor and friction control process therefor

• US 7,134,381 B2
• Filed: 08/19/2004
• Issued: 11/14/2006
• Est. Priority Date: 08/21/2003
• Status: Active Grant

• Current Assignee: Nissan Motor Co., Ltd.
• Original Assignee: Nissan Motor Co., Ltd.
• Inventors: Kano, Makoto, Hamada, Takahiro, Ueno, Takafumi
• Primary Examiner(s): Look, Edward K.
• Assistant Examiner(s): LESLIE, MICHAEL S
• Application Number:
  US10/921,346
• Publication Number:
  US 20050084390A1
• Time in Patent Office: 817 Days
• Field of Search: 92/122, 92/71, 92/72, 921/54, 921/55
• US Class Current: 92/71
• CPC Class Codes: C10M 171/008 Lubricant compositions compatible with refrigerants
• CPC Class Codes: C10M 2203/1006 used as base material
• CPC Class Codes: C10M 2207/022 containing at least two hydroxy groups
• CPC Class Codes: C10M 2207/0225 used as base material
• CPC Class Codes: C10M 2207/289 containing free hydroxy groups
• CPC Class Codes: C10M 2209/1033 used as base material
• CPC Class Codes: C10M 2209/1045 used as base material
• CPC Class Codes: C10N 2030/06 Oiliness; Film-strength; Anti-wear; Resistance to extreme pressure
• CPC Class Codes: C10N 2040/30 Refrigerators lubricants or compressors lubricants
• CPC Class Codes: C10N 2080/00 Special pretreatment of the material to be lubricated, e.g. phosphatising or chromatising of a metal
• CPC Class Codes: F04B 27/1036 Component parts, details, e.g. sealings, lubrication
• CPC Class Codes: F04B 39/0215 characterised by the use of a special lubricant
• CPC Class Codes: F04C 18/3446 the inner and outer member being in contact along more than one line or surface
• CPC Class Codes: F04C 2230/91 Coating
• CPC Class Codes: F05C 2203/0808 Carbon, e.g. graphite
• CPC Class Codes: F05C 2203/0882 Carbon, e.g. graphite
• CPC Class Codes: F05C 2253/12 Coating

Abstract

There is provided a refrigerant compressor including compressor parts having sliding portions slidable relative to each other and a refrigeration oil applied to the sliding portions of the compressor parts. At least one of the sliding portions of the compressor parts has a hard carbon coating formed thereon with a hydrogen content of 20 atomic % or less.

Claims

1. A refrigerant compressor, comprising:

compressor parts having sliding portions slidable relative to each other; and

a refrigeration oil applied to the sliding portions of the compressor parts,

wherein at least one of the sliding portions of the compressor parts comprises a hard carbon coating formed with a hydrogen content of 20 atomic % or less and wherein the refrigeration oil comprises at least one oxygen-containing organic compound as a friction modifier.

2. A refrigerant compressor according to claim 1, wherein the hard carbon coating has a hydrogen content of 10 atomic % or less.

3. A refrigerant compressor according to claim 2, wherein the hard carbon coating has a hydrogen content of 5 atomic % or less.

4. A refrigerant compressor according to claim 3, wherein the hard carbon coating has a hydrogen content of 0.5 atomic % or less.

5. A refrigerant compressor according to claim 1, wherein the sliding portion has a surface toughness Ra of 0.1 μ

m or smaller in a condition that the hard carbon coating has not yet been formed on the sliding portion.

6. A refrigerant compressor according to claim 1, wherein said at least one oxygen-containing compound is selected from the group consisting of alcohols, carboxylic acids, ethers, esters and derivatives thereof.

7. A refrigerant compressor according to claim 1, wherein the refrigeration oil has a base oil selected from the group consisting of mineral oils, synthetic oils and mixtures thereof.

8. A refrigerant compressor according to claim 1,

the compressor parts including:

a drive shaft;

a bearing;

a wobble plate supported by the bearing so as to make a reciprocating motion upon rotation of the drive shaft;

a guide ball fitted to the wobble plate;

a guide pin having a sliding portion slidably inserted through a sliding portion of the guide ball;

a cylinder having a cylinder bore formed therein;

a piston having a sliding portion slidably disposed in a sliding portion of the cylinder bore; and

a piston rod for transmitting the reciprocating motion of the wobble plate to the piston;

at least one of the sliding portions between the guide pin and the guide ball having a hard carbon coating formed with a hydrogen content of 20 atomic % or less; and

at least one of the sliding portions between the piston and the cylinder bore having a hard carbon coating formed with a hydrogen content of 20 atomic % or less.

9. A refrigerant compressor according to claim 1,

the compressor parts including:

a rotor shaft;

a rotor rotated together with the rotor shaft;

a plurality of vanes retractably attached to the rotor;

a ring disposed around the rotor and having a sliding portion slidable relative to a sliding portion of the rotor or vane; and

a pair of side plates disposed on open ends of the ring and having respective sliding portions slidable relative to sliding portions of the rotor or vane;

at least one of the sliding portions between the ring and the rotor or vane having a hard carbon coating formed with a hydrogen content of 20 atomic % or less; and

at least one of the sliding portions between the side plate and the rotor or vane having a hard carbon coating formed with a hydrogen content of 20 atomic % or less.

10. A refrigerant compressor, comprising:

compressor parts having sliding portions slidable relative to each other; and

a lubricant predominantly comprises a hydroxyl group containing compound applied to the sliding portions of the compressor parts,

wherein at least one of the sliding portions of the compressor parts comprises a hard carbon coating formed with a hydrogen content of 20 atomic % or less.

11. A refrigerant compressor according to claim 10, wherein the hydroxyl group containing compound is an alcohol.

12. A refrigerant compressor according to claim 11, wherein the alcohol is either glycerol or ethylene glycol.

13. A refrigerant compressor according to claim 10, wherein the hard carbon coating has a hydrogen content of 10 atomic % or less.

14. A refrigerant compressor according to claim 13, wherein the hard carbon coating has a hydrogen content of 5 atomic % or less.

15. A refrigerant compressor according to claim 14, wherein the hard carbon coating has a hydrogen content of 0.5 atomic % or less.

16. A refrigerant compressor according to claim 10, wherein the sliding portion has a surface roughness Ra of 0.1 μ

m or smaller in a condition that the hard carbon coating has not yet been formed on the sliding portion.

17. A refrigerant compressor according to claim 10,

the compressor parts including:

a drive shaft;

a bearing;

a wobble plate supported by the bearing so as to make a reciprocating motion upon rotation of the drive shaft;

a guide ball fitted to the wobble plate;

a guide pin having a sliding portion slidably inserted through a sliding portion of the guide ball;

a cylinder having a cylinder bore formed therein;

a piston having a sliding portion slidably disposed in a sliding portion of the cylinder bore; and

a piston rod for transmitting the reciprocating motion of the wobble plate to the piston;

at least one of the sliding portions between the guide pin and the guide ball having a hard carbon coating formed with a hydrogen content of 20 atomic % or less; and

at least one of the sliding portions between the piston and the cylinder bore having a hard carbon coating formed with a hydrogen content of 20 atomic % or less.

18. A refrigerant compressor according to claim 10,

the compressor parts including:

a rotor shaft;

a rotor rotated together with the rotor shaft;

a plurality of vanes retractably attached to the rotor;

a ring disposed around the rotor and having a sliding portion slidable relative to a sliding portion of the rotor or vane; and

a pair of side plates disposed on open ends of the ring and having respective sliding portions slidable relative to sliding portions of the rotor or vane;

at least one of the sliding portions between the ring and the rotor or vane having a hard carbon coating formed with a hydrogen content of 20 atomic % or less; and

at least one of the sliding portions between the side plate and the rotor or vane having a hard carbon coating formed with a hydrogen content of 20 atomic % or less.

19. A process for controlling sliding friction between compressor parts in a refrigerant compressor, the process comprising:

covering at least one of opposed sliding portions of the compressor parts with a hard carbon coating, while adjusting a hydrogen content of the hard carbon coating to 20 atomic % or less; and

applying a refrigeration oil comprising an oxygen-containing organic friction modifier, to a sliding interface between the sliding portions of the compressor parts.

20. A process according to claim 19, wherein the hydrogen content of the hard carbon coating is controlled to 10 atomic % or less.

21. A process according to claim 20, wherein the hydrogen content of the hard carbon coating is controlled to 5 atomic % or less.

22. A process according to claim 21, wherein the hydrogen content of the hard carbon coating is controlled to 0.5 atomic % or less.

23. A process for controlling sliding friction between compressor parts in a refrigerant compressor, the process comprising:

covering at least one of opposed sliding portions of the compressor parts with a hard carbon coating, while adjusting a hydrogen content of the hard carbon coating to 20 atomic % or less; and

applying a lubricant predominantly comprising of a hydroxyl group containing compound, to a sliding interface between the sliding portions of the compressor parts.

24. A process according to claim 23, wherein the hydrogen content of the hard carbon coating is controlled to 10 atomic % or less.

25. A process according to claim 24, wherein the hydrogen content of the hard carbon coating is controlled to 5 atomic % or less.

26. A process according to claim 25, wherein the hydrogen content of the hard carbon coating is controlled to 0.5 atomic % or less.