| 摘要 |
PURPOSE:To obtain a rotary power transmission device which can attain a high multiply or reduction speed ratio and has a little backlash by transmitting a rotating motion between rotary shafts having screw grooves and different diameters through balls disposed in the corresponding screw grooves. CONSTITUTION:When the first rotary shaft 1 is turned once, the speed of the second rotary shaft 3 is reduced to one integerth, and the speed of the third rotary shaft 6 is reduced to one squared integerth. At this time, the lead angles of screw grooves 8 are same, so that there causes no resistance against balls 9 at the lead angles, and the speed is reliably reduced without slipping of the balls 9. On the contrary, when the third rotary shaft is rotated as an input shaft, in contrast with the above operation, the speed of the second rotary shaft and the first rotary shaft are multiplied. |
