| 摘要 |
A chain or belt drive has one or more spiral chainwheels or pulleys. The driving chainwheel 5 is made to oscillate back and forth, perhaps by an eccentric cam. The driven chainwheel 3 also oscillates and drives the output shaft 1 through a one-way clutch 2. The cam driving the driving chainwheel may be shaped in such a way that a constant output speed is produced during the course of each forward stroke despite the continuously changing radius. Slack in the chain is taken up by a chain tensioner, or the spirals are shaped so that no slack occurs. The gearing ratio is changed by changing the relative positions of the output shaft and of the arc through which the driving chainwheel oscillates. The complete transmission generally consists of two or more of these drives, all mounted on the same output shaft and each taking the load in turn. <IMAGE> |
