Sleeve for Oil Film Bearing
A sleeve is disclosed for use in an oil film bearing of the type employed to rotatably support the tapered neck of a roll in a rolling mill. The sleeve is machined from a hollow forging of a base metal with a cylindrical outer surface and a tapered inner surface adapted to be seated on the tapered roll neck. The tapered inner surface of the sleeve is coated with a layer of material that is chemically dissimilar with respect to the base metal.
1 . A sleeve for use in an oil film bearing of the type employed to rotatably support the tapered neck of a roll in a rolling mill, said sleeve being machined from a hollow forging of a base metal with a cylindrical outer surface and a tapered inner surface adapted to be seated on said tapered neck, said tapered inner surface being coated with a layer of material that is chemically dissimilar with respect to said base metal.
2 . The sleeve of claim 1 wherein said layer is ablative.
3 . The sleeve of claim 2 wherein said layer comprises molybdenum-disulfide affixed to the surface with a heat activated binding agent.
4 . The sleeve of claim 1 wherein said layer comprises a chemical alteration of said base metal.
5 . The sleeve of claim 4 wherein said chemical alteration is produced by a vacuum furnace process.
6 . The sleeve of claim 2 or 3 wherein said layer has a hardness level lower than the hardness level of the base metal.
7 . The sleeve of claim 5 wherein said vacuum furnace process comprises plasma nitriding.
8 . The sleeve of claim 5 or 7 wherein said layer has a hardness level higher than that of the base metal.
9 . A sleeve for use in an oil film bearing of the type employed to rotatably support the tapered neck of a roll in a rolling mill, said sleeve being machined from a hollow forging of a base metal with a cylindrical outer surface and a tapered inner surface adapted to be seated on said tapered neck, said tapered inner surface being coated with a layer of material that is chemically dissimilar with respect to said base metal, said layer having a hardness which differs from the hardness of said base metal.