| 摘要 |
PROBLEM TO BE SOLVED: To obtain a disc drive motor which has improved structure including a frame and its surroundings, in order to achieve the cost reduction. SOLUTION: A frame 20 of a rotary shaft type disc drive motor 1A is a stamping manufactured by applying stamp to a steel plate, etc. Therefore, the finish with the inner diameter, out-of-roundness, etc., of a bearing retaining part 21, which have certain quality level or higher which cannot be obtained without secondary machining when casting, can be obtained. The thickness of the bearing retaining part 21 is not larger than 0.8 times the thickness of the bottom part 23 of the frame 20, and further, is not smaller than the maximum thickness of the outer rings 15A and 17A of ball bearings 15 and 17. With this constitution, even of accuracy of the inner diameter and out-of- roundness of the bearing retaining part 21 is relatively low, when the ball bearings 15 and 17 are accommodated in the retaining part 21, the bearing retaining part 21 may be distorted but the ball bearings 15 and 17 are never distorted. |
