Driving apparatus and method

摘要

A driving apparatus which includes a driving and driven belt pulleys at least one of which is constructed to change the effective diameter thereof, in response to the rotational speed of a driving power source. An endless v-belt serves as the driving connection between the driving and driven pulleys. The belt pulley with a changeable effective diameter has a first fixed pulley plate, a second slidable pulley plate and at least one weight operated by the centrifugal force acting thereon. The weight serves to shift the second pulley plate relative to the first pulley plate thereby to change the effective diameter of an annular groove defined between the first and second pulley plates with the increase of the centrifugal force. Therefore, the speed ratio of a driven unit to the driving power source is varied in response to the speed of the driving power source.