HIGH CONTACT FATIGUE LIFETIME GEAR AND MANUFACTURE THEREOF

摘要

PROBLEM TO BE SOLVED: To provide a high strength gear having excellent pitching fatigue strength by providing a gear with a working hardening layer at a specified depth over from a position close to a tooth root side than a tooth bearing part at a tooth root side to be engaged with other gear to, at least, a tooth bearing position at the tooth root side. ;SOLUTION: A tooth bearing position at a tooth root side as an engagement starting point of a gear is expressed with a point A, and a position at a tooth tip side is expressed with a point B, and contact of gears starts from the point A and finished at the point B. In real gear, the point A as a tooth bearing position at the both root side in not clearly defined because of the accuracy. A working hardening layer is therefor provided from a position closer to the tooth root than the point A to at least the point B. Namely, surface hardening treatment is performed to a gear, in a way having a working hardening layer at 0.2 mm of depth is provided at a position closer to the tooth root than the tooth bearing position to be engaged with other gear in this high contact fatigue lifetime gear. With this structure, pitching lifetime at the using time can be remarkably improved.;COPYRIGHT: (C)1999,JPO