Abstract
Power loss in a pushing metal V-Belt continuously variable transmission is analysed and compared with the experiment. The steady state equation for the belt-pulley is derived to calculate the force distribution assuming that the belt is a continuous body. The loss of belt-pulley, the dominant factor in the CVT, is estimated at band-band, band-block and band-pulley interfaces taking the pulley deflection into account. Loss models for the other parts are also suggested to estimate the total loss of CVT. The efficiency test for a small torque capacity CVT is performed using the dynamometer to validate the loss model of this paper. Test results @ full under-drive and 1:1 pulley ratio show good agreement with the theory, but there is a little discrepancy under full over-drive condition. The contribution of each part to the efficiency of the CVT is analysed by the theory. The belt-pulley and oil pump are the major loss factors of the CVT. The pulley deformation and the clearance between the moving and fixed sheaves should be minimized to improve the belt-pulley efficiency. The effect of the pulley pressure is also analysed quantitatively.
KEYWORDS – Metal V-Belt, Continuously Variable Transmission, Power Loss, Prediction