| 摘要 |
<p>A multispeed drive unit utilizes a single piston to toggle between multiple high and low gear reduction ratios. The drive unit includes a pair of clutch mechanisms, each of which acts upon a moveable ring gear of a planetary transmission. With the piston in a high-reduction position, one of the pair of clutch mechanisms engages while the other remains disengaged, such that the other planetary transmission components are allowed to rotate with respect to the ring gear, which is rotationally fixed. In this arrangement, the planetary transmission is operable to provide a high gear reduction. When the piston is shifted to a low-reduction position, the previously-engaged clutch mechanism disengages, and the previously-disengaged clutch mechanism engages. In this arrangement, the ring gear is free to rotate, and is fixed to the planet gear carrier of the planetary transmission, such that the planetary transmission provides no gear reduction. DMS US 51160904v1</p> |
