Axial Force and Efficiency Tests of Fixed Center Variable Speed Belt Drive

Report describes experiments which investigated interactions of the axial “sheave spreading” forces with centerline force and torque in a fixed center compound variable speed rubber belt drive at different speed ratios, speeds, and loads. An experimental rig, geometrically similar to a belt drive CVT, was designed and built, and operated at selected speed ratios, power levels, and total tension. The data provide a preliminary determination of variable speed belt CVT axial force control requirements and indicate high transmission efficiencies over a wide range of conditions when the axial forces are moderated to keep the traction coefficient within a certain range.