| 摘要 |
A bearing 4 is accommodated within a cylindrical bearing support portion 2 projecting from an end surface of a motor casing 1 made of a metal. The bearing 4 has an outer diameter smaller than the inner diameter of the bearing support portion 2 such that a clearance is formed between the bearing 4 and the bearing support portion 2. At an approximate center of the bearing 4 with respect to the thrust direction, a projection 19 is continuously or non-continuously formed on the inner circumferential surface of the bearing support portion 2 along a circular line centered on the motor shaft. Further, a depression 20 corresponding to the projection 19 is continuously or non-continuously formed on the outer circumferential surface of the bearing 4 along the circular line. Thus, the bearing 4 is supported within the bearing support portion 2 in such a manner that thrust movement is prevented, but slight tilting about the projection 19 is permitted. Therefore, run-out of a rotor and generation of noise do not occur even when the perpendicularity of the bearing and the bush relative to the motor shaft deteriorates slightly. <IMAGE> |
