| 摘要 |
<p>A bearing unit for rotatably supporting a shaft body (51), comprising a radial bearing (55) for supporting the bearing body for its peripheral rotation, a thrust bearing (58) for supporting one thrust-direction end of the shaft body, a housing (56) that has the radial and thrust bearings supporting the shaft body disposed therein and that is charged with a viscous fluid (67), and a spacer member (65) that is disposed in the housing and retains the spacing between the end surface of the radial bearing and one surface of a projection (54)disposed on the shaft body. Formed in the end surface of the radial bearing opposed to the one surface of the projection is a first dynamic pressure producing groove (63) for producing dynamic pressure due to the viscous fluid, while the surface of the thrust bearing opposed to the other surface of the projection is formed with a second dynamic pressure producing groove (64) for producing dynamic pressure due to the viscous fluid. The rotation of the shaft body results in the viscous fluid flowing in the first and second dynamic pressure producing grooves, thus producing a dynamic pressure between the shaft body and the radial and thrust bearings. The provision of the spacer member makes it possible to accurately control the spacings between the projection and the first and second dynamic pressure producing grooves.</p> |
