Title:
GEAR SUPERIOR IN FATIGUE LIFE STRENGTH IN CONTACT
Document Type and Number:
Japanese Patent JP3537357
Kind Code:
B2
Abstract:
PROBLEM TO BE SOLVED: To find a simple and effective measure for improving pitting fatigue life of a gear so that the gear withstands increased bearing pressure by load as a result of miniaturization, weight reduction and power increase of automobile parts especially for a gear ground after heat treatment for noise reduction.
SOLUTION: A material of the gear consists of, in weight %, 0.1-0.3% C, 0.3-1.5% Mn, 0.01-0.06% S, 0.3-1.5% Cr, and the balance Fe with inevitable impurities. Also the material has the maximum ratio (L/D) of a length of a long diameter L of MnS to that of a short diameter D being not more than 7, or the maximum length being not more than 12 μm, and no oxidation layer of grain boundary on the gear surface.
Inventors:
Toda, Masahiro
Ito, Seiji
Kanisawa, Hideo
Ito, Seiji
Kanisawa, Hideo
Application Number:
JP21063499A
Publication Date:
June 14, 2004
Filing Date:
July 26, 1999
Export Citation:
Assignee:
NIPPON STEEL CORP
TOYOTA MOTOR CORP
TOYOTA MOTOR CORP
International Classes:
F16H55/17; C22C38/00; C22C38/18; C22C38/50; (IPC1-7): C22C38/00; C22C38/18; C22C38/50; F16H55/17