| 摘要 |
PURPOSE:To provide a high-precision, high rigidity speed change device which enables speed change with any desired speed change ratio by furnishing a rotary shaft having No.1 and No.2 screws with different leads, and fitting the No.1 screw in a stationary nut while the No.2 screw in a follower nut which is capable only of rotating. CONSTITUTION:When a motor 18 rotates a rotary cylinder 8 in one direction, a rotary shaft 10 rotates. As No.1 screw 11 is fitted in a stationary nut 6, the rotaty shaft 10 moves in the axial direction. As No.2 screw 12 of the rotary shaft 10 is fitted in a follower nut 7 which is free to rotate and not capable of moving in the axial direction, the follower nut 7 rotates according to the difference between the leads L1, L2 of the screws 11, 12, and No.1 arm 3 will rotate. Accordingly the speed reduction ratio of the rotary shaft 10 and follower nut 7 is expressed as (L1-L2), and a any desired high speed reduction ratio can be obtained by setting the difference between L1 and L2 to a small value. |
