| 摘要 |
PROBLEM TO BE SOLVED: To promote cost reduction by using an integrally molded sleeve made of resin. SOLUTION: A dynamic pressure bearing for rotataly supporting a rotation polyhedral mirror 1 has the resin made sleeve 2 having dynamic pressure generating grooves 2a and 2b. When a collar 2c for positioning the sleeve 2 is projected with respect to a motor substrate 6, a recess in molding causes inner diameter size of the sleeve 2 to change to degrade bearing performance. Therefore, the collar 2c is disposed between the dynamic pressure generating grooves 2a and 2b to restrict thickness A of the sleeve 2, and axial thickness B and radial thickness C of the root of the collar 2c. |
