Claims
- 1. A coking-resistant bushing and pintle shaft sub-assembly for use in a pintle-type valve assembly, comprising:
a) a bushing having a bore therethrough; and b) a pintle shaft disposed in said bore and having an outer surface,
wherein at least one of said bore and said surface is at least partially relieved radially to define at least one residual bearing area for radially supporting said shaft in said bushing.
- 2. A sub-assembly in accordance with claim 1 wherein said pintle-type valve assembly includes a solenoid actuator assembly, and wherein the total area of said residual bearing area is selected such that coking deposits formed thereupon during use of said pintle-type valve may be sheared by the actuating force of said solenoid actuator.
- 3. A sub-assembly in accordance with claim 1 wherein a portion of said residual bearing area is formed in a helical shape.
- 4. A sub-assembly in accordance with claim 1 wherein a portion of said residual bearing area is formed in a shape comprising both a clockwise helix and a counterclockwise helix.
- 5. A sub-assembly in accordance with claim 1 wherein said valve is an exhaust gas recirculation valve for an internal combustion engine.
- 6. A sub-assembly in accordance with claim 1 wherein said radially relieved areas have a radial depth of at least 0.05 mm.
- 7. A coking-resistant pintle-type valve assembly, comprising:
a) a valve body including an internal chamber; b) a bushing disposed in a first bore in said valve body and having a second bore extending between said chamber and the exterior of said valve body; and c) a valve pintle shaft axially disposed in said second bore and extending into said chamber and having a shaft surface,
wherein at least one of said second bore and said shaft surface is at least partially relieved radially to define at least one residual bearing area for radially supporting said shaft in said bushing.
- 8. An internal combustion engine, comprising a coking-resistant pintle-type exhaust gas recirculation valve assembly having
a valve body including an internal chamber, a bushing disposed in a first bore in said valve body and having a second bore extending between said chamber and the exterior of said valve body, and a valve pintle shaft axially disposed in said second bore and extending into said chamber and having a shaft surface,
wherein at least one of said second bore and said shaft surface is at least partially relieved radially to define at least one residual bearing area for radially supporting said shaft in said bushing.
RELATIONSHIP TO OTHER APPLICATIONS AND PATENTS
[0001] The present application claims priority from U.S. Provisional Patent Application, Serial No. 60/415,584, filed Oct. 2, 2002.
Provisional Applications (1)
|
Number |
Date |
Country |
|
60415584 |
Oct 2002 |
US |