| 摘要 |
<P>PROBLEM TO BE SOLVED: To provide a ball bearing of high rotation and low torque most suitable to support a rotation axis of a small universal motor such as a motor for an electric tool, a fan motor, etc., where generation of fretting abrasion of a side surface part of an inner ring is prevented and high fitting performance to a shaft is exhibited. <P>SOLUTION: This ball bearing is devised so that a pitch diameter Dp of a rotating element 13 is set smaller than a cross-section central diameter Dm and a diameter Db of the rotating element 13 is set less than 50% of thickness (w) in the radial direction. Additionally, a shape of an outer peripheral surface 12b of the inner ring 12 is formed linear toward an end surface in the axial direction of the inner ring 12 from an end part 12c of an inner ring raceway surface 12a and is constituted so as to secure a large flat surface part on a side surface part 12d. <P>COPYRIGHT: (C)2004,JPO |
