| 摘要 |
PURPOSE:To reduce the difference in the temperatures of the inner and outer rings of a main shaft, to reduce the gap of bearings and to prevent a seizure accident, by providing a circulation passage of the coolant of the main shaft and cooling the bearings from the inside of the main shaft. CONSTITUTION:An air curtain is formed with a main shaft being rotated and a pressure air being injected to the both end parts of before and after labyrinth seal faces by passing air passes 2c, 12b. A cooling oil is fed from a feeding port 8a, fed to six spline grooves 4a of the main shaft center hole via a rotary joint 8, the oil passing three grooves 4a is fed to an oil hole 4b via an oil pass 4c and the inner races of the main shaft 4 and bearing 3 are cooled. The oil having come out of the oil pass 4c is popped out of the opening of an oil pass 10a by the centrifugal force by the main shaft rotation, received by the inner peripheral groove 12c of a cover 12 and returned to a tank from a discharging pass 12a. On the other hand, the oil passing the other three of the grooves 4a is popped out of the opening of an oil pass 11a via an oil pass 4d, received by an inner peripheral groove 2d, passed through an oil pass 2a and fed to an oil jacket 2b to cool the bearing 3. |
