| 摘要 |
PURPOSE:To allow an arbitrary planning of the ratio of a rotary angle to a linear displacement and to reduce the size of a device, by locating a ball, being capable of moving in and out from a ball circulating passage, at the intersection of a screwed groove in a ball screw and a screwed groove in a ball nut. CONSTITUTION:A ball screw has a screwed groove in which it moves forward by a distance of l1 by one complete turn, and a ball nut has a screwed groove in which it moves backward by a distance of l2 by one full turn. A ball 5 is located at the intersection, marked with a circle, of the two screwed grooves. If the ball 5 rolls on the periphery by a distance of L by a relative rotation between the ball screw and the ball nut, a ball screw 1 is displaced by a distance of (l1/L1)L and the ball nut is displaced in the opposite direction thereto by a distance of (l2/L2)L, and thereby the ball screw and the ball nut are relatively displaced in a linear manner by a distance of (l2/L2-l1/L1)L. Additionally, the L is a distance proportional to a rotary angle, and the distance of (l2/L2-l1/L1) is equivalent to a factor of proportionality which converts rotation into straight movement. The distance can be planned in any small value. |
