| 摘要 |
PURPOSE:To eliminate backlash nearly perfectly by closely engaging at least three roller elements with the spiral cam of a cam member and executing the deceleration transmission of the revolution movement in an exceedingly stable state. CONSTITUTION:When a shaft 30 is rotatingly-driven by the quantity corresponding to a prescribed dividing angle in the direction shown by the arrow A by a dividing motor, also a cam member 20 is revolved in the same direction to the arrow A. In this case, the roller element 74 of a turret cam-engaged with each part of the spiral cam parts of the half parts 26 and 28 of the cam member 20 is rolled in the directions of arrows B and C in close contact stated along the prescribed cam surface of the spiral cam part, and shifted over the dividing angle of the turret in the revolution direction shown by the arrow D and then stops. In this case, over the whole period of the driving operation, the close contact state between five or six roller elements 74 and the spiral cams 44 and 46 of the cam member 20 is prepressure-maintained, always uniformly. Therefore rigidity can be increased, and backlash can be eliminated nearly perfectly, and the speedy dividing operation can be obtained. |
