Patent ID: 6827496
Filing Date: 2004-12-07
Classification: F16C

Abstract:
A four-point contact ball bearing comprising:an inner ring and an outer ring defining raceway grooves, respectively, each of the raceway grooves comprising: two circular arcs different in curvature provided on opposite sides of a widthwise center of the raceway groove; and a plurality of balls arranged between the inner and outer rings so that the balls can roll, wherein 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, wherein a curvature radius of the raceway groove of the outer ring is selected to be greater than 55% and not greater than 56.5% of a diameter of the ball.