Bearing for alternator and bearing for pulley
AssigneeNtn Corporation
InventorsChikara Ohki, Tomoaki Goto
Life of this patent
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Abstract
A bearing for alternators and a bearing for pulleys for reducing hydrogen embrittlement or cracking is used when the bearing is in an environment having a severe condition, such as, when hydrogen is generated from grease or the like. The bearing includes a rolling element, an inner ring and an outer ring, and at least one of the rolling element, where the inner and outer rings have a nitrogen enriched layer containing austenite crystal grains having a grain size number exceeding 10.
Claims2
A bearing for an alternator, supporting a rotor shaft having one end with a pulley attached thereto and having a belt engaged therearound to transmit a driving force to said pulley to allow said rotor shaft to rotate a rotor, the bearing having a rolling element, an inner ring and an outer ring, at least one of said rolling element and said inner and outer rings having a nitrogen enriched layer and containing austenite crystal grains having a grain size number exceeding 10,
- wherein said at least one of said rolling element and said inner and outer rings having said nitrogen enriched layer has a surface layer containing globular carbide having an area ratio of no less than 10%, and said at least one of said rolling element and said inner and outer rings is formed of steel of SUJ2 as defined by JIS.
A bearing posed between a pulley having a belt engaged therearound and a rotative shaft passing through said pulley, the bearing comprising a rolling element, an inner ring and an outer ring, at least one of said rolling element and said inner and outer rings having a nitrogen enriched layer and containing austenite crystal grains having a grain size number exceeding 10,
- wherein said at least one of said rolling element and said inner and outer rings having said nitrogen enriched layer has a surface layer containing globular carbide having an area ratio of no less than 10%, and said at least one of said rolling element and said inner and outer rings is formed of steel of SUJ2 as defined by JIS.
Dependencies are inferred from the claim text.