| 摘要 |
PROBLEM TO BE SOLVED: To provide a dynamic pressure bearing to ensure stable rotation and allowing suppression of the costs. SOLUTION: At the peripheral surface of a shaft 14, grooves 62 stretching in the circumferential direction are formed in such a way as mating with the upper part and lower part of a sleeve 40. The upper and lower grooves 62 are formed for 180 degs. around the axis in the same radial direction of the shaft 14. When the sleeve 40 rotates round the shaft 14, a dynamic pressure is generated between the shaft 14 and sleeve 40. The dynamic pressure generating area differs in the two areas with and without grooves about the axis interposed, and according to the formula that the force = pressure×area, the sleeve 40 can rotate stably in the condition that a force F is applied in the radial direction on the side free of such grooves 62. |
