Research on a novel discrete adjustable radiuses type continuously variable transmission

In order to explore a novel type of continuously variable transmission (CVT) with discrete adjustable radius pulley (DAR-pulley), which can directly change the driving and driven pulley diameters, are proposed. In particular, we focus on the feasibility of this novel-type structure. The DAR-CVT system consists of a pair of DAR-pulleys, input and output cones, speed changing actuator, and tensioning system. The operating principle is described, and the theoretical transmission ratio model is derived. Then, the force and speed modeling are performed to evaluate the mechanical property and kinematic feasibility of the DAR-CVT system computationally. Additionally, a method for calculating the critical friction force of the DAR-CVT is proposed, and the rationality of using average radius and line speed is verified. The multi-body dynamic simulation reveals a certain degree of volatility in the output speed of DAR-CVT, but the speed fluctuation is within the allowable range. Finally, a prototype is developed to prove the feasibility of the DAR-CVT.