| 摘要 |
A machine tool includes a tool spindle rotatably mounted in a housing. A tool member is disposed in a front spindle segment of the spindle and is releasably clamped by a clamping member. An actuating member is mounted in and is axially movable relative to the spindle to actuate the clamping member. First and second anti-friction bearings are interposed between the housing and the spindle and have different outer diameters. A preload actuating member is disposed to force the second anti-friction bearing in the axial direction to take up the slack in a non-actuated state of the second anti-friction bearing when the spindle is running in a higher speed, thereby resuming the anti-friction function of the second anti-friction bearing when running the tool spindle at a lower speed is intended. |
