| 摘要 |
<p>A continuously variable drive ratio transmission includes a support (10), a first shaft (16) rotatably mounted to the support so that the shaft (16) can rotate about a first axis, a helical rack (18) supported by the first shaft (16) so that the rack has a plurality of toothed convolutions (18a) spaced apart along the first shaft, the diameters of said convolutions (18a) being such that together they define an imaginary conical envelope encircling the first shaft (16). A second shaft (26) is rotatably mounted to the support (10) so that the second shaft is spaced from and extends parallel to the envelope, and a gear member (32) is mounted to the second shaft (26) for rotation therewith, the gear member (32) having teeth which mesh with those of the rack (18). The gear member (32) is slidable along the second shaft (26) so that the gear member may be positioned at any location along the rack (18). The gear member (32) comprises a pair of pinions (26a, 26b) positioned side by side on the second shaft (26) which are rotatable through small angles relative to the second shaft and relative to each other, a first resilient member (74) which biases one (64b) of the pinions to a home angular position on the second shaft (26) and a second resilient member (78) which biases the pinions (64a, 64b) relatively so that their teeth are in alignment.</p> |
