Study on Forces Transmitting Between Pulleys and Blocks of a Block-Type CVT Belt 921746
The purpose of this paper is to analyze the force distribution between pulleys and blocks of a newly developed CVT belt. Three components of the force (transmitting force, normal force and frictional force) were measured directly using a newly devised pulley. The experimental results reveal that the transmitting force distribution on the driving pulley is similar to that on the driven pulley as long as blocks do not slip while the distribution of the normal force component for both pulleys does not resemble each other as well as the distribution of friction force in the radial direction of the pulley. It is also found that no idle arc exists in the contact arc of both driven and driving pulleys even in the case that the transmitting torque is low.
The experimental force distribution is compared with a theory based on the discrete spring model taking no consideration of slippage between the pulley and the blocks. Until the block slips in the groove of the pulley, the theoretical result for the transmitting forces both on the driven and driving pulleys well coincides with the experimental one, while it does not agree with the experiment for other force distributions except for the normal force on the driven pulley.