The novel mechanism CVT (Shaft Drive CVT, S-CVT) was developed by the authors. It transmits power by a traction drive same as the half toroidal CVT. S-CVT has parallel input/output shafts with conical or concave disks and the idler shaft having conical rollers at both ends, which is placed perpendicularly to the input/output shafts. All disks and rollers can move along each axis directions, and these movements produce the ratio changing by the changes of the rotational radii. The efficiency is the key evaluation function of CVT. To improve the efficiency, the backup roller mechanism was devised. Its effectiveness was confirmed by the experiment, and the efficiency of 95% was obtained by modified prototype S-CVT. This paper deals with the expansion of ratio range of S-CVT. In case of using the present disks, S-CVT has a difficulty to expand the narrow ratio range of 4 (0.5 to 2) because of the large slip brought by the spin. To expand the ratio range, the zero-spin disk/roller was devised. The shape of zero-spin disk/roller satisfies the condition that the spin does not occur at any speed ratio. According to the calculation, the slip rate becomes less than 1% at any speed ratio. To confirm the effectiveness, the prototype S-CVT with zero-spin disk was manufactured. It has the ratio range of 0.43 to 2.35. To obtain the slip rate the experiments were carried out at the speed ratio of 0.43, 1 and 2.35. At each speed ratio, the slip rate of less than 1% was obtained, and the effect of the zerospin disk was confirmed.
A convenient and accurate parallel Input/Output USB device for E-Prime
