Expansible chamber devices – Relatively movable working members – Interconnected with common rotatable shaft
Reexamination Certificate
2001-06-01
2003-04-08
Look, Edward K. (Department: 3746)
Expansible chamber devices
Relatively movable working members
Interconnected with common rotatable shaft
C029S888020
Reexamination Certificate
active
06543333
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to a swashplate type compressor for compressing a gas. More specifically, the present invention relates to an enriched cobalt—tin coating alloy that is particularly well suited for providing a coating surface on an aluminum or aluminum alloy swashplate of such a compressor. The present invention also provides a method of coating a swashplate with an enriched cobalt—tin coating alloy.
BACKGROUND OF THE INVENTION
Swashplate type compressors are frequently used in refrigeration circuits such as those used in automotive applications. These compressors operate through an engagement between one or more pistons and a swashplate. Rotation of the swashplate; which is oriented at an angle to the axis of rotation of a drive shaft, causes the engaged pistons to reciprocate within individual cylinder bores. This reciprocation allows the pistons to compress the refrigerant as part of the mechanical refrigeration process.
A pair of shoes are disposed between each piston and swashplate and swivel within concave pockets as the swashplate rotates. The interface between the shoes and swashplate is an area of sliding contact, giving rise to friction and wear. Over time, wear can lead to seizure of the compressor, especially in conditions in which lubricant supply to the swashplate is inadequate. This failure mode is one principal limitation on the useful life of a swashplate type compressor. Problems of maintaining low friction sliding contact between the shoes and swashplate are especially challenging for swashplates made of aluminum and aluminum alloys, because these materials are relatively soft, yet have abrasive qualities.
SUMMARY OF THE INVENTION
The present invention provides a swashplate-type compressor having a coating disposed on the aluminum or aluminum alloy swashplate. The coating preferably comprises a multi-layered structure on the surface of the swashplate substrate. Preferably, the coating is placed on the substrate in at least the areas that come into contact with the shoes. In a preferred embodiment, a base layer of tin is disposed on the substrate, and a layer of cobalt-tin is disposed on the tin layer. The cobalt-tin layer comprises between 12 and 28 weight % cobalt, with the balance comprising tin. In a preferred embodiment, the cobalt-tin layer comprises about 22 weight % cobalt, with the balance comprising tin.
The present invention provides a high weight percentage of cobalt in the surface coating layer. These layers can be deposited by chemical or electroplating deposition processes. However, electroplating is preferred since it allows for the achievement of higher cobalt concentrations, which improves the seizure resistance of the swashplate and compressor.
Electroplating deposition processes, when used in connection with this invention, also allows for the elimination of a second polishing step normally required for chemical deposition, commonly referred to as “superfinishing”. This step is normally required to achieve a desired chemically reactive surface of the swashplate and is done immediately prior to chemical coating. The enriched-cobalt-tin alloy according to the present invention provides a desirable coating that can be electroplated onto a machined surface. Such surfaces can be obtained in a single machining operation, and thus superfinishing can be eliminated. Consequently, the coating alloy and method of the present invention when applied by electroplating offers significant time and expense savings over coatings deposited by chemical conversion techniques.
REFERENCES:
patent: 1101220 (1914-06-01), Tebbetts
patent: 1443870 (1923-01-01), McArthur et al.
patent: 1654509 (1927-12-01), Claus
patent: 2022917 (1935-12-01), Larkin et al.
patent: 2741018 (1956-04-01), Schaefer
patent: 2766195 (1956-10-01), Combs et al.
patent: 3669719 (1972-06-01), Doede et al.
patent: 3947607 (1976-03-01), Gazzard et al.
patent: 4037522 (1977-07-01), Inoshita et al.
patent: 4244679 (1981-01-01), Nakayama et al.
patent: 4263814 (1981-04-01), Takaoka et al.
patent: 4285640 (1981-08-01), Mukai
patent: 4363854 (1982-12-01), Hodes et al.
patent: 4435482 (1984-03-01), Futamura et al.
patent: 4503179 (1985-03-01), Yoshimura et al.
patent: 4562122 (1985-12-01), Hodes et al.
patent: 4573878 (1986-03-01), Ohno et al.
patent: 4591536 (1986-05-01), Hodes et al.
patent: 4662267 (1987-05-01), Kaku et al.
patent: 4666787 (1987-05-01), Bickle et al.
patent: 4723572 (1988-02-01), Tuymer
patent: 4790727 (1988-12-01), Steele
patent: 4795682 (1989-01-01), Turner et al.
patent: 4830933 (1989-05-01), Hodes et al.
patent: 4935056 (1990-06-01), Miyasaka
patent: 5056417 (1991-10-01), Kato et al.
patent: 5087529 (1992-02-01), Engel et al.
patent: 5116692 (1992-05-01), Mori et al.
patent: 5167726 (1992-12-01), Loiacono et al.
patent: 5242657 (1993-09-01), Sahu
patent: 5286444 (1994-02-01), Tomikawa et al.
patent: 5330712 (1994-07-01), Singh
patent: 5413756 (1995-05-01), Sahu
patent: 5445896 (1995-08-01), Tanaka et al.
patent: 5468130 (1995-11-01), Yamada et al.
patent: 5655432 (1997-08-01), Wilkosz et al.
patent: 5712049 (1998-01-01), Huhn et al.
patent: 5864745 (1999-01-01), Kawagoe et al.
patent: 5875702 (1999-03-01), Kawagoe et al.
patent: 5911809 (1999-06-01), Cordy
patent: 5938864 (1999-08-01), Tomikawa et al.
patent: 5943941 (1999-08-01), Kato et al.
patent: 5996467 (1999-12-01), Churgay et al.
patent: 6123009 (2000-09-01), Kanayama et al.
patent: 6136454 (2000-10-01), Cordy
patent: 6189434 (2001-02-01), Kawaguchi et al.
patent: 6192784 (2001-02-01), Kato et al.
patent: 1577557 (1980-10-01), None
patent: 3147226 (1981-11-01), None
patent: 3447 194 (1986-07-01), None
patent: 0 024 507 (1980-06-01), None
patent: 0 218 274 (1986-08-01), None
patent: 0 244 396 (1987-04-01), None
patent: 0 244 619 (1987-06-01), None
patent: 0 713 972 (1996-05-01), None
patent: 0 776 986 (1997-06-01), None
patent: 0 854 286 (1998-07-01), None
patent: 0 890 743 (1999-01-01), None
patent: 0 911 517 (1999-04-01), None
patent: 0 926 340 (1999-06-01), None
patent: 0 992 683 (2000-04-01), None
patent: 1 106 704 (2001-06-01), None
patent: 1 116 881 (2001-07-01), None
patent: 1 118 768 (2001-07-01), None
patent: 1461371 (1977-01-01), None
patent: SHO 60-22080 (1985-02-01), None
patent: 60022080 (1985-02-01), None
patent: WO99/19625 (1999-04-01), None
patent: WO99/50556 (1999-10-01), None
patent: WO99/50557 (1999-10-01), None
patent: WO01/04492 (2001-01-01), None
Cordy Carl Edward
Griffin William J.
Ramamurthy Ram
Lazo Thomas E.
Look Edward K.
Visteon Global Technologies Inc.
LandOfFree
Enriched cobalt-tin swashplate coating alloy does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Enriched cobalt-tin swashplate coating alloy, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Enriched cobalt-tin swashplate coating alloy will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3106375