| 摘要 |
PURPOSE:To generate a large damping force and thereby to provide a high-precision rotation without vibration by providing in the side portion of a roll bearing formation unit a magnetic fluid seal, a constrictor film surface member, and a fine gap filled with a magnetic fluid. CONSTITUTION:An inner rolling surface member 2 is fixed in the cylinder of an inner rolling-element supporting member 1, and an outer rolling surface member 4 in the cylinder of an outer rolling-element supporting member 3, with rolling elements 5 inserted between the members 2 and 4. To the member 3 is fixed a magnetic fluid seal 8 consisting of a permanent magnet 6 and disc-shaped yokes 7 which nip the magnet 6 and of which the inside peripheral surfaces form a fine gap between the member 1 and themselves. Between the yokes 7 is fixed a constricting oil film surface member 9 which forms a fine gap between itself and the member 1. This constitution enables generation of a pressure corresponding to the speed of the change of the gap, the pressure serving as a damping force for the gap change. |
