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US 2005/0101392 A1Published application
Power transmission shaft
AssigneeNtn Corporation
InventorsKatsuhiro Sakurai, Kisao Yamazaki
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AssigneeNtn Corporation
InventorsKatsuhiro Sakurai, Kisao Yamazaki
Estimating the term…
An object of the present invention is to provide a technique for improving a strength, especially a fatigue strength of a power transmission shaft provided with a serrated portion for torque transmission such as a spline shaft. A power transmission shaft is serration-fitted to an inner joint member of respective constant velocity joints. A drive shaft is provided with a serrated portion as well as a smooth portion having a cylindrical outer circumferential surface. A cut-up portion is formed at the end portion of the serrated portion. When applying an induction hardening to the smooth portion and the serrated portion, a hardening ratio of the smooth portion is set at a different value from that of the serrated portion, and such that a fatigue strength of the smooth portion becomes equal to or greater than that of the serrated portion.
A power transmission shaft coupled to an inner joint member or an outer joint member of a constant velocity joint, and provided with a smooth portion having an outer circumferential surface of a cylindrical shape and a serrated portion for torque transmission having a cut-up portion at an end portion thereof,
Dependencies are inferred from the claim text.