Improvement of Power to Weight Ratio of Shaft Drive CVT Using Zero-Spin Disk : 3rd Report, Improvement of Power to Weight Ratio by Giving Large Loading Force(Machine Elements, Design and Manufacturing)

Abstract

A novel mechanism CVT (Shaft Drive CVT, S-CVT) was developed by the authors. The use of zero-spin disk and roller was proposed in order to increase the power to weight ratio, because the power to weight ratio is important index for applying the S-CVT to automobiles. The amount of spin caused by the changing in the contact point is less than 0.9% using the zero-spin disk and roller. Their performance has been confirmed theoretically and by the experiment. In this report, the effect of novel zero-spin disk and roller is evaluated using a prototype CVT. A hydraulic cylinder is equipped to give a large loading force. A counter shaft, which connects the two backup rollers to transmit the torque between them, is added to enlarge the torque capacity. The power to weight ratios are improved to 1.4 and 3.0 times compared with those of present concave disk at high and low ratio, respectively. The maximum value is 72.3W/kg at high ratio in the case of transmitted torque of 195Nm.