| 摘要 |
A variable-speed drive unit, in particular for a variable-speed drive device, such as a riding mower, includes at least one belt transmission between two pulleys, each mounted on a shaft, each pulley including variably-spaced flanges. In this variable-speed drive unit, each pulley has a flange that equipped with a loading device that tends to exert, in a permanent manner and in the active state of the transmission, an axial effort in the direction in which the flanges move toward the pulley to clamp the belt between the flanges, whereby one of the pulleys has a loading device that exerts a lesser axial effort than the other device, and whereby one of the pulleys also includes, independently of the loading device, a manual control element for drawing together or separating flanges that can exert on the flange a slight control effort corresponding essentially to the power difference of the loading devices. |
