JPS643359A - Continuously variable automatic transmission - Google Patents

Abstract

PURPOSE:To make the captioned device a simple structure by linking the shaft body of a rotation driving means to the driving wheel body of a driving force transmitting means using a body via an elastic means. CONSTITUTION:When a driving sprocket 4 is energized counterclockwise via a driving shaft 1, a load, i.e., the road surface resistance of a rear wheel acts on the driving wheel 4 as a tensile force T in a tangential direction via driven sprocket 6 and a chain 5. Accordingly, since the driving sprocket 4 is pulled by the tensile force T while being energized counterclockwise by the driving shaft 1, due to the composition of both, the driving sprocket 4 is relatively moved to the driven sprocket 6 side with respect to the driving shaft 1, expanding/contracting the lengths of coil springs 3. In the figure, a spring 3a is contracted, springs 3b, 3e are almost neither expanded nor contracted, and springs 3c, 3d are expanded. Hence, the radius of gyration (effective diameter) on the driving side of the driving sprocket 4 is reduced by a displaced quantity E to r1a with respect to that r1 at an undriven time with its rate being proportionate to the tensile force T. Accordingly, the ratio of effective diameters of both sprockets 4, 6 (change gear ratio) becomes large.