| 摘要 |
PURPOSE:To prevent the inflow of a lubricant into a disk chamber while suppressing torque loss by using a lubricant relatively low in viscosity for one of a pair of bearing members, and using a lubricant relatively high in viscosity for the other. CONSTITUTION:An upper bearing 3 is a ball bearing type, and a magnetic fluid seal mechanism 9 is provided in the vicinity, and a lubricant relatively low in viscosity is used for it. By the magnetic fluid seal mechanism 9, the outside and the inside of the spindle motor are sealed surely, and the diffusion of the mist of the lubricant into a disk chamber 10 is prevented. A lower bearing 4 is ball bearing type, and labyrinth mechanism 12 is arranged in the vicinity, and a lubricant relatively low in viscosity is used for it. The viscosity of the lubricant is made relatively large, whereby the splash of the lubricant itself is suppressed, and the labyrinth effect is improved. The torque loss is suppressed, and the inflow of the mist of the lubricant into the disc chamber is prevented. |
