Automotive infinite transmission

Abstract

In an automotive infinite transmission, a rotation of an input pulley is transmitted to an output pulley through a belt in such a manner that a transmission ratio is continuously variable. Each of the input and output pulleys has a fixed pulley member fixedly mounted on a rotary shaft and a movable pulley member mounted on the rotary shaft for axial movement toward and away from the fixed pulley member. A tapered pulley surface of the fixed pulley member cooperates with a tapered pulley surface of the movable pulley member to define therebetween an annular groove having a generally V-shaped cross-section. A plurality of drive blocks are arranged between the pulley surfaces of the respective fixed and movable pulley members and circumferentially along the annular groove with the drive blocks being in sliding contact with the pulley surfaces. Provision is made between the drive blocks and the pulley surfaces in sliding contact therewith for reducing frictional forces. When the movable pulley member is moved axially relative to the fixed pulley member, the drive blocks are moved along generally radially extending slits formed in the tapered pulley surfaces of the respective movable and fixed pulley members. The drive blocks are biased radially inwardly against a centrifugal force due to the rotation of the movable and fixed pulley members.