| 摘要 |
PURPOSE: To apply fine positioning to the shift angle by dynamically altering the preload between cones and the ball of a ball joint to desired levels. CONSTITUTION: This ball-type pivot joint is provided with a ball 50, a pair of opposing bearing members 52, 53, and a pair of cones 67, 68 which are dynamically preloaded by the servo control of a preload actuator 55. When a stage or another device is in motion, the prelaod is reduced to provide low friction and wear. When the stage or the other device is not in motion, the preload is increased to provide zero backlash and high stiffness. |
