The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 07, 2004
Filed:
Aug. 27, 2002
Applicant:
Inventors:
Takashi Iwata, Nara, JP;
Yoshitaka Nakagawa, Osaka, JP;
Assignee:
Koyo Seiko Co., Ltd., Osaka, JP;
Attorney:
Primary Examiner:
Int. Cl.
CPC ...
F16C 3/358 ;
U.S. Cl.
CPC ...
F16C 3/358 ;
Abstract
A four-point ball bearing includes: an inner ring and an outer ring defining raceway grooves, respectively. Each of the raceway grooves is constituted by two circular arcs different in curvature provided on opposite sides of a widthwise center of the raceway groove. A plurality of balls are arranged between the inner and outer rings so that the balls can roll. In at least one of the raceway grooves, a center of curvature of one of the circular arcs and a center of curvature of the other circular arc are displaced from each other at least in a radial direction so that spin is generated in each of the balls.