| 摘要 |
PURPOSE:To prevent a magnetic fluid from outflowing to the outside due to the thermal expansion of a lubricating fluid in use of the magnetic fluid for lubricant by providing a space between a magnetic fluid seal and bearing section and supporting a lubricating mechanism for lubricating fluid utilizing the rotation of a shaft by the bearing. CONSTITUTION:A magnetic fluid seal 2 consisting of a permanent magnet 3, magnetic pole piece 4, cover 5 and magnetic fluid 12 is provided coaxially with a bearing housing 14, while first and second radial bearings 6, 7 and a thrust bearing 8 are disposed. Lubricating fluid 11 is enclosed to an end b of the first radial bearing 6 and fluid paths a-d are formed by the bearing housing 14, radial bearings 6, 7 and rotary shaft 1 while a thrust bearing 8 is formed with a circulating path passing through a gap F and holes 9, 10 formed of a lubricating film formed by the rotation of the rotary shaft 1. The magnetic fluid seal 2 is stuck to the opened end side of the bearing housing 14 to be spaced from the first radial bearing 6 so that the lubricating fluid is blocked from outflow to the outside. |
