Hollow roller
AssigneeKoyo Seiko Co., Ltd.
InventorsKeiji Suzuki, Kouichi Ueda
Life of this patent
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Abstract
A hollow roller which comprises a hardened outer surface, and a non-hardened inner surface which has not been subjected to carburization process, whereby soft portions remain at the inner surface of the hollow roller in order to prevent the inner surface from being cracked in response to external shock. Preferably, the hollow roller is applied to a planet roller or a cylindrical roller.
Claims11
A thin-sectional hollow roller, disposed rotatably between a first rotatable member and a second stationary member, comprising:
- a hardened outer surface;
- a pair of hardened end surfaces adjacent to both sides of said hardened outer surface;
- and
- a non-hardened soft inner surface;
- whereby soft portions remain at said inner surface of the hollow roller in order to prevent said inner surface from being cracked in response to external shock.
A method of preparing a hollow roller having a hardened outer surface and a non-hardened inner surface comprising:
- providing a hollow roller of a soft metallic material having an outer surface including end surfaces and an inner surface;
- and
- selectively subjecting said hollow roller to a hardening means such that said outer surface of said hollow roller inclusive of said end surfaces are hardened while said inner surface remains soft.
A method of preparing a plurality of hollow rollers with a hardened outer surface and a non-hardened inner surface which comprises:
- providing a plurality of hollow rollers of a soft metallic material having an outer surface including end surfaces and an inner surface;
- inserting a shaft into said hollow of said hollow rollers;
- and
- selectively subjecting said plurality of hollow rollers to a hardening process such that said outer surfaces of said rollers are hardened while said end surfaces and inner surfaces of said rollers remain soft.
Dependencies are inferred from the claim text.