| 摘要 |
PURPOSE:To improve rotation transmission efficiency by fitting balls stating in the screw groove of a ball track provided in a driving screw shaft, into the groove of a ball track provided in a groove gear for speed increasing and decreasing. CONSTITUTION:The screw groove 3 of a ball track is provided on a screw shaft 1, and the end and the beginning of the groove are continued to each other through a circulating track 4 on the inner portion and the outer circumference of the screw shaft 1. The groove 5 of a ball track facing to the screw groove 3 of the ball track is provided on a groove gear 2 for increasing and decreasing speed. Balls 6 are continuously charged in the screw groove 3 of the ball track to freely roll and move. Accordingly, the balls 6 move by rolling to make the groove gear 5 for increasing and decreasing rotation at speed under the predetermined increased/decreased speed. Therefore, friction coefficient is very small so that rotation transmission efficiency is improved. |
