Title:
MECHANICAL PART HAVING ROLLING ELEMENTS
Document Type and Number:
WIPO Patent Application WO/1995/007417
Kind Code:
A1
Abstract:
A mechanical part consisting of an outer member having a race surface on the inner side therof, an inner member having a race surface on the outer side thereof, and rolling elements inserted between the race surfaces of these outer and inner members. Mechanical parts of this kind include a hub bearing and a constant-speed universal joint for automobiles, which are required to reduce the dimensions and weight thereof. The outer member having a complicated shape is formed out of medium carbon steel which can be processed easily, and its race surface is subjected to induction hardening, so that the resultant hardened surface layer can ensure a sufficient abrasion resistance. However, how to prolong the lifetime of the rolling elements, such as balls, used under a high surface pressure but increasingly reducted in weight, is posing a problem. The mechanical part according to the present invention has an induction hardened layer as a race surface layer of its outer member, and consists of medium carbon steel containing 0.50-0.70 % by weight of carbon and 0.5-1.0 % by weight of silicon and/or aluminum. The rolling elements rolling or slidingly moving on the mentioned race surfaces are formed out of hardened and tempered high carbon chromium bearing steel, and have carbonitrided surface layer, and this enables the lifetime of the rolling elements under a high surface pressure to be improved.
Inventors:
TSUSHIMA NORIYUKI (JP)
NAKAJIMA HIROKAZU (JP)
NAKAJIMA HIROKAZU (JP)
Application Number:
PCT/JP1993/001278
Publication Date:
March 16, 1995
Filing Date:
September 08, 1993
Export Citation:
Assignee:
NTN TOYO BEARING CO LTD (JP)
TSUSHIMA NORIYUKI (JP)
NAKAJIMA HIROKAZU (JP)
TSUSHIMA NORIYUKI (JP)
NAKAJIMA HIROKAZU (JP)
International Classes:
B60B27/00; F16C33/32; F16C33/62; F16D3/224; (IPC1-7): F16C33/62
Foreign References:
| JPH03199340A | 1991-08-30 | |||
| JPH02125841A | 1990-05-14 | |||
| JPH04194415A | 1992-07-14 | |||
| JPS57178902A | 1982-11-04 | |||
| JPS5022726A | 1975-03-11 |
Other References:
See also references of EP 0718513A4
Download PDF: