Cleaning and liquid contact with solids – Apparatus – For work having hollows or passages
Reexamination Certificate
1999-02-05
2001-04-17
Stinson, Frankie L. (Department: 1746)
Cleaning and liquid contact with solids
Apparatus
For work having hollows or passages
C134S152000, C015S304000
Reexamination Certificate
active
06216710
ABSTRACT:
TECHNICAL FIELD OF THE INVENTION
The present invention generally relates to a process for manufacturing permeable metal parts, and more specifically to a method and apparatus for removing quench oil from such permeable metal parts.
BACKGROUND OF THE INVENTION
Self lubricating powder metal bearings have been manufactured by the powder metal industry since the 1930's. These bearing are traditionally compacted from bronze metal powder, sintered, and then impregnated with a lubricating oil. A sealed self lubricating bearing releases lubricating oil as the bearing heats from friction, and then absorbs the oil back into the porosity of the bearing after it cools. The advent of copper ferrous alloys in the 1940's allowed the manufacture of self lubricating powder metal bearings which are made of steel, and can be heat treated for high wear and high compressive strength applications. These bearings are compacted from iron copper alloy powders, sintered, heat treated, tempered, and then impregnated with the lubricating oil.
A drawback to self lubricating bearing sleeves that have heretofore been used is that a liquid can became absorbed in the porous powdered metal bearing sleeve during its manufacture prior to impregnating the bearing sleeve with the lubricant. In particular, in order to strengthen the powdered metal bearing sleeve, the bearing sleeve may be quenched in oil during a heat treatment process. While the heat treatment process significantly strengthens the bearing sleeve, the quench oil is absorbed into the pores of the powered metal structure. A drawback to absorbing quench oil into the pores is that the quench oil occupies volume within the pores that would otherwise be impregnated with lubricant.
One method of removing the quench oil is to heat the bearing sleeve in a furnace to combust the quench oil within the pores. However, combusting the quench oil has the drawback of creating smoke and fires within the furnace. The smoke and fire are not only inconvenient, but also releases a significant amount of pollution into the environment. In addition, the combustion of the quench oil within the pores leaves residual combustion products within the pores. These residual combustion products can significantly reduce the volume of the pores. A drawback to the reduced pore volume is that the amount of lubricant that can subsequently be absorbed by the powdered metal bearing sleeve is reduced thereby decreasing the effectiveness of the self lubricating bearing sleeve.
What is needed therefore is a method and apparatus for removing quench oil from a powdered metal bearing sleeve which overcomes the above-mentioned drawbacks.
DISCLOSURE OF THE INVENTION
In accordance with a first aspect of the present invention, there is provided a method of removing liquid from pores contained in a permeable metal part. The part has a tubular construction defining an interior surface and an exterior surface having an upper end opening and a lower end opening at an opposite end thereof. The method includes the step of sealing the upper end opening and the lower end opening of the permeable metal part so as to define an closed interior chamber. The method further includes the steps of injecting a cleaning fluid into the closed interior chamber. The method yet further includes the step of pressurizing the interior chamber with a gas at a pressure sufficient to cause the cleaning fluid to permeate through the pores from the interior surface to the exterior surface. The liquid is forced through the exterior surface and removed from the pores.
In accordance with a second aspect of the present invention, there is provided an apparatus for removing liquid from a permeable metal part. The permeable metal part entraps a quantity of liquid in pores defined therein. The permeable metal part also defines an upper end opening and a lower end opening. The apparatus includes a first sealing member which seals the lower end opening and a second sealing member which seals the upper end opening. The permeable metal part, the first sealing member, and the second sealing member define an closed interior chamber. The apparatus further includes a compressor operable to fill the interior chamber with pressurized gas and an injector operable to inject cleaning fluid into the interior chamber. The injector injects cleaning fluid into the interior chamber. The compressor pressurizes the interior chamber with the pressurized gas. The cleaning fluid is advanced by the pressurized gas from the interior chamber to an exterior of the permeable metal part via the pores so as to remove the entrapped liquid from the pores.
REFERENCES:
patent: 2774362 (1956-12-01), Nordling
patent: 3608567 (1971-09-01), Neill, Jr.
patent: 3765051 (1973-10-01), Wanat
patent: 3921248 (1975-11-01), Effenberger et al.
patent: 3998656 (1976-12-01), Grotto
patent: 4090309 (1978-05-01), Rollins
patent: 4299245 (1981-11-01), Clapper
patent: 4585019 (1986-04-01), Jacobson
patent: 4750505 (1988-06-01), Inuta et al.
patent: 4808234 (1989-02-01), McKay et al.
patent: 5001805 (1991-03-01), Stouky et al.
patent: 5078763 (1992-01-01), Blount-Gillette
patent: 5163486 (1992-11-01), Rogers et al.
patent: 5305493 (1994-04-01), Prenn
patent: 5332448 (1994-07-01), Phillips
patent: 5339843 (1994-08-01), Benedict et al.
patent: 5419351 (1995-05-01), Ciari
patent: 5444892 (1995-08-01), Ris et al.
patent: 5524652 (1996-06-01), Neubauer
White Scott E.
Winkler Harold E.
Caterpillar Inc.
Morrison John W.
Stinson Frankie L.
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