| 摘要 |
<p>PURPOSE:To vary the revolution speed of a base plate by rotatably fitting two driving gears each havng a sun gear and an internal gear fixed, and also rotatably fitting planet gears engaging with both said gears on the base plate. CONSTITUTION:A driving-side pulley 2 having a sun gear 3 fixed and a driving- side pulley 6 having an internal gear 7 are fitted rotatably on a shaft 12. Planet gears 13 and 14 engaging with the gear 3 and gear 7 are fitted rotatably to a carrier 10 forming a driven-side rotating member, and the carrier 10 is stuck to the shaft 12 to rotate together with the shaft 12. As the sun gear 3 rotates as shown by an arrow A, the planet gears 13 and 24 generate turning forces as shown by an arrow B to rotate as shown by an arrow C. The rotation of the internal gear also allows the planet gears 13 and 24 to rotate around the shaft 12 as well. Thus, the speed of a belt which is not shown in the figure and abuts on the pulleys 2 and 6 is controlled to adjust the revolution speed of the shaft 12 successively in the forward and reverse directions over a wide range, thus suitably performing speed control over the reel of VTR.</p> |
