| 摘要 |
PURPOSE:To obtain prepressurizing effect of a plurality of spheres of a rolling bearing having high reliability with a simple structure by providing electromagnetic means for generating a motor power and a force for axially attracting a motor shaft and prepressurizing the spheres by this attracting force. CONSTITUTION:A motor pulley 12 is press-fitted to a motor shaft 10. A radial race 18 is press-fitted into the top of a motor housing 16, and a bearing housing 20 is press-fitted into the bottom. In order to obtain a motor power, a pair of permanent magnets 28, 30 which generate magnetic fluxes are bonded fixedly to the inside of a motor housing 16. A rotor 32 is affected by an attracting force of the direction of an arrow 36 via the permanent magnets 28, 30. This attracting force is acted to urge by the race surface 12a of a motor pulley 12 steel balls 22 to the race surface 24a of a thrust race 24. Accordingly, the balls 22 are restricted in an axial movement of the shaft 10, thereby accurately rotating around the shaft. |
