US4802332A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Sliding surface lubrication particularly advantageous for a free piston stirling engine
Assignee: Sunpower Inc
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Filing: 1987-11-20
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Granted: 1989-02-07
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Expires: 2007-11-20
Abstract
Abstract A Stirling cycle engine is provided with gas cavities at an interface between an engine piston and a mating surface that guides the piston in its reciprocative motion to thereby achieve improved lubrication with the resulting gas film.
Inventors
- 👤 William T. Beale
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-04 16:56
CPC Classifications
F; F02; F02G; F02G1/00; F02G1/04; F02G1/043; F02G1/053; F02G1/0535; F02G1/0435; F16; F16J; F16J1/00; F16J1/08; F02G2243/00; F02G2243/02; F02G2243/04; F02G2243/08; F02G2253/00; F02G2253/02
Claims Analysis
Total Claims: 13
Claim 1
Independent Claim
90 words
In an engine having opposed spaces that are each filled with fluid and have an imposed cyclic pressure difference variation, the engine further having a piston member that separates said spaces, has an outer bearing surface, and moves within and relative to a female bearing member having an interior bearing surface interfacing the bearing of the piston, a lubricating means comprising a plurality of fluid cavities opening to the interfacing bearing surfaces for the cyclic intake and exhaust of said fluid out of phase with said imposed cyclic pressure variation.
Claim 2
Dependent Claim
90 words
In an engine having opposed spaces that are each filled with fluid and have an imposed cyclic pressure difference variation, the engine further having a piston member that separates said spaces, has an outer bearing surface, and moves within and relative to a female bearing member having an interior bearing surface interfacing the bearing of the piston, a lubricating means comprising a plurality of fluid cavities opening to the interfacing bearing surfaces for the cyclic intake and exhaust of said fluid out of phase with said imposed cyclic pressure variation.
Claim 3
Dependent Claim
25 words
The invention defined by claim 1 wherein the fluid cavities are of one size and are distributed uniformly over the path of said piston member.
Claim 4
Dependent Claim
31 words
The invention defined by claim 1 wherein the fluid cavities are of at least two different sizes, said different sizes being mixed and distributed over the path of said piston member.
Claim 5
Dependent Claim
21 words
The invention defined by claim 1 wherein said piston member is a free power piston of a free piston Stirling engine.
Claim 6
Dependent Claim
20 words
The invention defined by claim 1 wherein said piston member is a displacer piston of a free piston Stirling engine
Claim 7
Dependent Claim
18 words
The invention defined by claim 4 wherein said cavities are positioned in a housing guiding said power piston.
Claim 8
Dependent Claim
18 words
The invention defined by claim 5 wherein said cavities are positioned in a rod guiding said displacer piston.
Claim 9
Dependent Claim
16 words
The invention defined by claim 1 wherein the cavity is formed by a resiliently expansible receptacle.
Claim 10
Dependent Claim
67 words
In an engine having mating surfaces formed by a piston surface and by a bearing surface guiding said piston surface, the improvement comprising one of said mating surfaces having fluid cavities which open only to the mating surfaces and which provide a film of lubricating fluid between said mating surfaces when said piston surface is worked on relative to said bearing surface by a fluid pressure differential.
Claim 11
Dependent Claim
67 words
In an engine having mating surfaces formed by a piston surface and by a bearing surface guiding said piston surface, the improvement comprising one of said mating surfaces having fluid cavities which open only to the mating surfaces and which provide a film of lubricating fluid between said mating surfaces when said piston surface is worked on relative to said bearing surface by a fluid pressure differential.
Claim 12
Dependent Claim
34 words
The invention defined by claim 9 wherein said fluid cavities are comprised of an entrance opening and a cavity opening connected to the entrance opening, said cavity opening being larger than said entrance opening.
Claim 13
Dependent Claim
24 words
The invention defined by claim 9 wherein said gas cavities are situated and distributed in diametrical symmetry over the extent of said mating surfaces.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1992-02-07 | 1992-08-08 | 1993-02-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1996-02-07 | 1996-08-08 | 1997-02-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2000-02-07 | 2000-08-08 | 2001-02-07 | $7700.00 | Window Closed / Lapsed |