| 摘要 |
PURPOSE:To stabilize rotational torque and prevent the rise of startup torque by supporting both ends of a main spindle with a casing cover plate and a bottom bearing part and providing a seal ring between the upper surface of the large diameter part of the main spindle and the lower surface of a cover part. CONSTITUTION:The upper end part of a main spindle 2 is supported with a bearing part 5 fitted to the cover part 4 of a casing 6 and the lower end part 10 is supported with another bearing part 11 formed on the bottom surface 7 of the casing 6. A large diameter part 3 is formed on the main spindle 2 and a seal ring 9 is fitted between the upper surface of the large diameter part 3 and the lower surface of the cover part 4, and supported with a support division 12 provided at the cover part 4. According to the aforesaid construction, the contact of the main spindle 2 and the like with the casing 6 due to inclination can be prevented and a gap between the bottom surface 7 and the lower surface of the large diameter part 3 is kept constant, thereby keeping the quantity of a brake fluid 8 constant in the gap and stabilizing rotational torque. Furthermore, the pressure of the seal ring 9 is applied only in an axial direction and the rise of startup torque is thereby prevented. |
