| 摘要 |
PROBLEM TO BE SOLVED: To reduce resistance that a shaft body receives, in a bearing unit comprising a holder which holds each of spheres of a ball bearing.SOLUTION: A watch bearing unit comprises a shaft body 143 which is rotated around an axis and a bearing 181a which supports the shaft body in a rotatable manner. The bearing includes a plurality of spheres 183 disposed in a circumferential direction of the shaft body so as to be abutted to an outer circumferential surface of the shaft body, an outer ring 185 which holds the spheres with the shaft body, and a holder 189a including a body part 212a which is provided between the shaft body and the outer ring and holds the plurality of spheres mutually at fixed intervals. The body part has lightweight portions 204 which are provided at equal intervals in the circumferential direction around the shaft body and reduces a mass of the holder. |
