| 摘要 |
<p>Disclosed is a speed change system with a planetary gear assembly. When first and second sun gear portions, which lie in input and output stages respectively, rotate as a single body by an input rotational force, first and second ring gear portions, which lie in the input and output stages respectively, are also rotated as asingle body by the medium of first planetary gears of the input stage. The second sun gear portion and the second ring gear portion rotate in opposite directions and in different tangential velocities. By these rotations, each of second planetary gears engaged with both the second sun gear portion and the second ring gear portion rotates around its axis and revolves, at the same time, along the second ring gear portion. An output rotation can be obtained from a second planet carrier coupled with the second planetary gears. The variable speed ratio of the system is determined by a difference between two tangential velocities of the second sun gear portion and the second ring gear portion.</p> |
