Self tensioned belt gear - has annular outer wheel at one end with inner offset tensioning gear wheel

摘要

To transmit rotary power from a driving wheel to a driven wheel (10) through a belt (17), the belt gearing uses an annular outside wheel (14) with either the driving or driven wheel. The annular outside wheel has an internal gear formed on its inner circumferential surface to operatively engage the outer circumferential surface of an inner wheel (12) in the central hollow portion. This transmits power from the outside wheel to the wheel inside. The belt extends between the outer circumferential surface of the outside wheel and the remaining one of the driving and driven wheels. The outside wheel is displaceable relative to the inner wheel to adjust automatically the tension of the belt.