| 摘要 |
PURPOSE:To prevent different lubricating fluids from mixing with each other and from overflowing, by enclosing a magnetic fluid in one of plural thrust gaps and enclosing air in the other. CONSTITUTION:Radial bearings 16R, 17R employ a magnetic fluid as lubricant. A dynamic pressure thrust bearing 16T also employs a magnetic fluid as lubricant. Another dynamic pressure thrust bearing 17T employs air as lubricating fluid. The radial bearings 16R, 17R comprise shallow herringbone grooves 16Ra, 17Ra cut in a shaft 2 or in the inside surface of a rotation assisting member 3 which has a slightly larger diameter than the shaft 2, and the lubricant filling the grooves 16Ra, 17Ra. Since the thrust bearing 17T having the air as lubricant always receives a strong thrust from the thrust bearing 16T having the magnetic fluid as lubricant and the viscosity of the air is kept nearly constant by temperature, the clearance of the thrust bearing 17T is maintained in a stable position. |
