Rotary compressor with reduced lubrication sensitivity

• US 5,947,710 A
• Filed: 06/16/1997
• Issued: 09/07/1999
• Est. Priority Date: 12/07/1995
• Status: Expired due to Fees

• Current Assignee: Carrier Corporation (Carrier Global Corporation)
• Original Assignee: Carrier Corporation (Carrier Global Corporation)
• Inventors: Mertell, Martin M., Cooper, Clark V., Bushnell, Paul J.
• Primary Examiner(s): Vrablik, John J.
• Application Number:
  US08/877,018
• Time in Patent Office: 813 Days
• Field of Search: 418/63, 418/178, 428/408, 428/457, 428/634
• US Class Current: 418/63
• CPC Class Codes: F01C 21/0809 Construction of vanes or vane holders
• CPC Class Codes: F04C 18/356 with vanes reciprocating with respect to the outer member
• CPC Class Codes: F04C 18/3564 the surfaces of the inner and outer member, forming the working space, being surfaces of revolution
• CPC Class Codes: F04C 2210/26 Refrigerants with particular properties, e.g. HFC-134a
• CPC Class Codes: F04C 2230/91 Coating
• CPC Class Codes: F04C 23/008 Hermetic pumps
• CPC Class Codes: F05C 2203/0808 Carbon, e.g. graphite
• CPC Class Codes: F05C 2203/0813 Carbides
• CPC Class Codes: F05C 2253/08 Crystalline
• CPC Class Codes: Y10T 428/12625 Free carbon containing component
• CPC Class Codes: Y10T 428/30 Self-sustaining carbon mass or layer with impregnant or other layer

Abstract

Lubrication deficiencies related to the use of lubricants in HFC refrigeration compressors can be mitigated by providing a diamond-like-carbon coating on a member subject to wear due to lubrication deficiencies. Specifically, the tip of the vane of a rotary compressor is coated with a diamond-like-carbon coating made up of alternating layers of tungsten carbide and a lubricious material 0.5 to 5.0 microns thick.

Claims

1. An improved rotary compressor for compressing HFC refrigerant which is lubricated by a synthetic lubricant, said rotary compressor having pump means including a piston rollably disposed within a bore of a cylinder and a vane having a tip coacting with said piston, the improvement comprising:

said tip having a diamond-like-carbon coating thereon made up of a series of alternating hard and lubricious layers whereby the coefficient of friction between said tip and said piston is reduced and said tip has reduced wear even in the absence of sufficient lubricant as compared to a tip without said diamond-like-coating.

2. A high side rotary compressor for compressing HFC refrigerant which is lubricated by a lubricant selected from the group consisting of mineral oils, alkylbenzene, polyvinyl ether and polycarbonate lubricants comprising:

shell means having a first end and a second end;

cylinder means containing pump means including a vane and a piston coacting with said cylinder means to define suction and compression chambers;

said cylinder means being fixedly located in said shell means near said first end and defining with said first end a first chamber which has an oil sump containing said oil lubricant;

first bearing means secured to said cylinder means and extending towards said oil sump;

second bearing means secured to said cylinder means and extending towards said second end;

motor means including rotor means and stator means;

said stator means fixedly located in said shell means between said cylinder means and said second end and axially spaced from said cylinder means and said second bearing means;

eccentric shaft means supported by said first and second bearing means and including eccentric means operatively connected to said piston;

said rotor means secured to said shaft means so as to be integral therewith and located within said stator so as to define therewith an annular gap;

suction means for supplying gas to said pump means;

discharge means fluidly connected to said shell means;

said vane having a tip coacting with said piston;

said tip having a diamond-like-carbon coating thereon made up of a series of alternating hard and lubricious layers whereby the coefficient of friction between said tip and piston is reduced and said tip has reduced wear even in the absence of sufficient lubricant as compared to a tip without said diamond-like-coating.

3. The compressor of claim 2 wherein said oil sump contains said lubricant.

4. The compressor of claim 2 wherein said coating is 0.5 to 5.0 μ

m thick.

5. The compressor of claim 4 wherein said series is made up of a plurality of bilayers 1 to 20 nm thick.

6. The compressor of claim 2 wherein said series is made up of a plurality of bilayers 1 to 20 nm thick.

7. The compressor of claim 2 wherein said lubricious layers are amorphous carbon.

8. The compressor of claim 7 wherein said hard layers are an amorphous assemblage of carbon and a transition metal.

9. The compressor of claim 7 wherein said hard materials are an amorphous assemblage of carbon and a transition metal.

10. A high side rotary compressor for compressing HFC refrigerant which is lubricated by a synthetic lubricant comprising:

shell means having a first end and a second end;

cylinder means containing pump means including a vane and a piston coacting with said cylinder means to define suction and compression chambers;

said cylinder means being fixedly located in said shell means near said first end and defining with said first end a first chamber which has an oil sump containing said oil lubricant;

first bearing means secured to said cylinder means and extending towards said oil sump;

second bearing means secured to said cylinder means and extending towards said second end;

motor means including rotor means and stator means;

said stator means fixedly located in said shell means between said cylinder means and said second end and axially spaced from said cylinder means and said second bearing means;

eccentric shaft means supported by said first and second bearing means and including eccentric means operatively connected to said piston;

said rotor means secured to said shaft means so as to be integral therewith and located within said stator so as to define therewith an annular gap;

suction means for supplying gas to said pump means;

discharge means fluidly connected to said shell means;

said vane having a tip coacting with said piston;

said tip having a diamond-like-carbon coating thereon made up of a series of alternating hard and lubricious layers whereby the coefficient of friction between said tip and piston is reduced and said tip has reduced wear even in the absence of sufficient lubricant as compared to a tip without said diamond-like-coating.

11. The compressor of claim 10 wherein said oil sump contains said lubricant.

12. The compressor of claim 10 wherein said coating is 0.5 to 5.0 μ

m thick.

13. The compressor of claim 12 wherein said series is made up of a plurality of bilayers 1 to 20 nm thick.

14. The compressor of claim 10 wherein said series is made up of a plurality of bilayers 1 to 20 nm thick.

15. The compressor of claim 10 wherein said lubricious layers are amorphous carbon.

16. The compressor of claim 15 wherein said hard layers are an amorphous assemblage of carbon and a transition metal.

17. The compressor of claim 15 wherein said hard materials are an amorphous assemblage of carbon and a transition metal.