Patent ID: 7575528
Filing Date: 2009-08-18
Classification: F16H

Abstract:
1. A continuously variable transmission comprising: an input cone pulley pair on an input shaft and an output cone pulley pair on an output shaft wherein an encircling mechanism spanning the input and the output cone pulley pairs to transfer torque between the input and the output cone pulley pairs at a transmission ratio proportional to a ratio of the spacings between the cone pulleys of the input and the output cone pulley pairs and being variable between a low transmission ratio range and a high transmission ratio range, hydraulic devices connected with a hydraulic pressure supply for axially displacing the moveable cone pulleys of the input and the output cone pulley pairs in opposing directions to control the spacings between the respective cone pulleys of the input and the output cone pulley pairs, and in the high transmission ratio range of the input moveable cone pulley, a recoil spring solely engages the input moveable cone pulley and a contact surface fixed to the moveable cone pulley such that no force is exerted on the moveable cone pulley and, in the low transmission ratio range of the input moveable cone pulley, the recoil spring exerts a spring force on the input moveable cone pulley to axially displace the input moveable cone pulley toward the high transmission ratio range, an axially fixed contact surface and the input moveable cone pulley at least partially defining a pressure chamber, and the recoil spring being located within the pressure chamber, and in a deactivated state of the hydraulic pressure supply, the spring force of the recoil spring is sufficient to axially displace the input moveable cone pulley toward the high transmission ratio range.