Process for manufacturing rolling contact member, process for manufacturing rolling bearing, raceway member of rolling bearing and rolling bearing
AssigneeNtn Corporation
InventorsKikuo Maeda, Yuji Okamoto
Life of this patent
Estimating the term…
Abstract
A process for manufacturing a rolling contact member comprises preparing a steel member consisting of a steel containing 0.7 mass % or more of carbon; performing hot forging of the steel member prepared in the steel member preparation step to thereby obtain a blank ring as the first forged member; performing turning of the blank ring obtained in the hot forging step to thereby remove part of the blank ring; and performing cold forging of the blank ring wrought in the first turning step to thereby obtain a stepped ring. In the steps subsequent to the cold forging step, on the stepped ring, the area wrought in the first turning step is not subjected to cutting.
Claims7
A process for manufacturing a raceway member comprising:
- a steel member preparation step of preparing a steel member made of steel containing at least 0.7 mass % of carbon;
- a hot forging step of preparing a first forged member by hot-forging said steel member prepared in said steel member preparation step to form the first forged member having an annular shape;
- an annealing step of annealing said first forged member to form an annealed first forged member;
- a first cutting step of removing a part of said annealed first forged member by cutting said first forged member;
- a cold forging step of preparing a second forged member by cold-forging said annealed first forged member cut in said first cutting step to form the second forged member as a stepped ring having a first annular portion and a second annular portion wherein a diameter of an opening in the first annular portion is greater than a diameter of an opening in the second annular portion;
- and
- a second cutting step of removing a part of said second forged member wherein
- an area of said second forged member cut in said first cutting step is not cut in a step subsequent to the cold forging step.
Dependencies are inferred from the claim text.