US3890069A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Coating for rotary engine rotor housings and method of making
Assignee: Ford Motor Co
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Filing: 1973-07-05
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Granted: 1975-06-17
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Expires: 1993-07-05
Abstract
Abstract A rotor housing for a rotary internal combustion engine is disclosed having a wear-resistant coating system characterized by high temperature hardness stability and controlled porosity to improve the lubricating characteristics of the surface-to-surface engagement with the rotary apex seals. The coating system comprises a self-fused composite of martensitic stainless steel powder and an equally hard powder consisting of a nickel-based alloy. Powder particle size is controlled to render a smoother machined surface and sub-surface porosity. An intermediate transition coating may be used consisting of a composition selected from nickel aluminide, arc sprayed nickel, molybdenum, all effective to operate as a bonding intermediate to a supporting aluminum structure. A method of producing the wear-resistant coating system for a rotor housing is disclosed, comprising preparation of an aluminum casting having a supporting epitrochoid end wall, machining a reference, embedment of thermally resistant plugs about certain openings in the end wall, removing a uniform layer of said casting end wall to a predetermined depth, soft grit blasting of the removed surface, coating of the margins about ports in the end wall with an anti-bond material flame spraying the entire end wall with a mixture of martensitic stainless steel and a nickelbased alloy, immersing said coated casting in oil for a predetermined period of time immediately after coating, and grinding off a portion of said coating to the depth of said reference.
Inventors
- 👤 Yeshwant P Telang
- 👤 James C Uy
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 02:09
CPC Classifications
F; F02; F02B; F02B55/00; F01; F01C; F01C19/00; F01C19/005; Y; Y02; Y02T; Y02T10/00; Y02T10/10; Y02T10/12; Y10; Y10T; Y10T29/00; Y10T29/49; Y10T29/49229; Y10T29/49231; Y10T29/49234
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
57 words
A WEAR AND CHATTER RESISTANT COATING SYSTEM FOR THE ROTOR HOUSING OF A ROTARY INTERNAL COMBUSTION ENGINE, THE SYSTEM COMPRISING: A. A SUPPORT PORTION COMPRISES OF A MATERIAL HAVING A THERMAL CONDUCTIVITY FACTOR AT LEAST EQUIVALENT TO ALUMINUM, AND B. AN OUTER EXPOSED PORTION COMPRISES OF AN ADMIXTURE OF GENERALLY EQUALLY HARD POWDER PARTICLE TYPES, ONE TYPE
Claim 2
Dependent Claim
57 words
A WEAR AND CHATTER RESISTANT COATING SYSTEM FOR THE ROTOR HOUSING OF A ROTARY INTERNAL COMBUSTION ENGINE, THE SYSTEM COMPRISING: A. A SUPPORT PORTION COMPRISES OF A MATERIAL HAVING A THERMAL CONDUCTIVITY FACTOR AT LEAST EQUIVALENT TO ALUMINUM, AND B. AN OUTER EXPOSED PORTION COMPRISES OF AN ADMIXTURE OF GENERALLY EQUALLY HARD POWDER PARTICLE TYPES, ONE TYPE
Claim 3
Dependent Claim
40 words
The system as in claim 1, in which the deposited particles exhibit a solidification structure whereby the martensitic stainless steel particles appear as spheres, the nickel-based alloy particles appear acicular and oxides or interstitial oxygen exist as randomly oriented pockets.
Claim 4
Dependent Claim
36 words
The system as in claim 1, in which the porosity of said exposed layer varies from about 9% at the base of the exposed layer to about 6% at the exposed surface of the exposed layer.
Claim 5
Dependent Claim
17 words
The system as in claim 1, in which said nickel-based alloy comprises 2.0-8.0% silicon and 1.5-4.5% boron.
Claim 6
Dependent Claim
107 words
In a rotary internal combustion engine having a combustion chamber arranged for planetary movement of a rotor therein, the improvement comprising: a. means defining an epitrochoid shaped supporting end wall forming part of said combustion chamber and adapted for continuous engagement by the extremities of said rotor, and b. a coating system metallurgically bonded to substantially the entire internal surface of said end wall, said system comprising a wear-resistant layer for interengagement with said rotor and an adherency transition layer interposed between said supporting end wall and said wear-resistant layer, said wear-resistant layer consisting essentially of a surface-fused mixture of martensitic stainless steel and a nickel-based alloy.
Claim 7
Dependent Claim
107 words
In a rotary internal combustion engine having a combustion chamber arranged for planetary movement of a rotor therein, the improvement comprising: a. means defining an epitrochoid shaped supporting end wall forming part of said combustion chamber and adapted for continuous engagement by the extremities of said rotor, and b. a coating system metallurgically bonded to substantially the entire internal surface of said end wall, said system comprising a wear-resistant layer for interengagement with said rotor and an adherency transition layer interposed between said supporting end wall and said wear-resistant layer, said wear-resistant layer consisting essentially of a surface-fused mixture of martensitic stainless steel and a nickel-based alloy.
Claim 8
Dependent Claim
27 words
The improvement as in claim 5, in which said intermediate layer comprises a composition selected from the group consisting of nickel aluminide, arc sprayed nickel and molybdenum.
Claim 9
Dependent Claim
46 words
The improvement as in claim 5, in which said structure further comprises means for maintaining a positive supply of oil across the entire exposed surface of said rotor housing, said rotor housing having an operative dynamic coefficient of friction in the range of 0.005 to 0.02.
Claim 10
Dependent Claim
156 words
In a rotary internal combustion engine having a combustion chamber arranged for planetary movement of a rotor therein, the combination comprising: a. a rotor housing defining an epitrochoid shaped supporting end wall, b. a rotor carrying a plurality of apex seals effective to continuously engage the rotor housing during planetary movement, each seal presenting an engaging surface comprised of a composition selected from the group consisting of cast iron, aluminum-carbon, tungsten carbide, electroplated composite of nickel-silicon carbide and chromium, c. a coating system metallurgically bonded to substantially the entire surface of said rotor housing end wall, said coating system comprising an exposed wear-resistant layer for engagement by said rotor seals, said exposed layer consisting essentially of a self-fused powder composite of martensitic stainless steel and a nickel-based alloy having a hardness generally equal to said stainless steel, said composite having a hardness value of at least Rockwell C 30 at an elevated operating temperature of 400*F.
Claim 11
Dependent Claim
156 words
In a rotary internal combustion engine having a combustion chamber arranged for planetary movement of a rotor therein, the combination comprising: a. a rotor housing defining an epitrochoid shaped supporting end wall, b. a rotor carrying a plurality of apex seals effective to continuously engage the rotor housing during planetary movement, each seal presenting an engaging surface comprised of a composition selected from the group consisting of cast iron, aluminum-carbon, tungsten carbide, electroplated composite of nickel-silicon carbide and chromium, c. a coating system metallurgically bonded to substantially the entire surface of said rotor housing end wall, said coating system comprising an exposed wear-resistant layer for engagement by said rotor seals, said exposed layer consisting essentially of a self-fused powder composite of martensitic stainless steel and a nickel-based alloy having a hardness generally equal to said stainless steel, said composite having a hardness value of at least Rockwell C 30 at an elevated operating temperature of 400*F.
Claim 12
Dependent Claim
49 words
The combination as in claim 8, in which said rotor housing has at least opening in said end wall for receiving means to ignite a combustible mixture in said combustion chamber, and an annular plug being recessed in said end wall about said opening and consisting essentially of carbon.
Claim 13
Dependent Claim
14 words
The combination as in claim 9, in which said plug consists essentially of copper.
Claim 14
Dependent Claim
38 words
The combination as in claim 9, in which the housing further contains an exhaust port at one location in the surface of said supporting end wall, said coating system being absent from a predetermined margin of said port.
Claim 15
Dependent Claim
23 words
The system as in claim 1, in which said coating system has a generally uniform thickness in the range of 0.01- 0.03 inch.
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) | 1978-06-16 | 1978-12-16 | 1979-06-17 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1982-06-16 | 1982-12-16 | 1983-06-17 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1986-06-16 | 1986-12-16 | 1987-06-17 | $7700.00 | Window Closed / Lapsed |