PURPOSE: To simplify the structure of an automatic pressure regulating cam mechanism for a friction pulley by installing each of tangential cam grooves on the surface of a rotational member being opposed to a friction type continuously variable transmission clamped to a compressor part, and holding a ball between these cam grooves.
CONSTITUTION: A compressor and a friction type continuously variable transmission are solidly connected to each other, supporting an output disk 5 on an input shaft free of rotation, and it is connected to an output shaft via an automatic pressure regulating cam mechanism 20. This automatic pressure regulating cam mechanism 20 consists of a cam disk 21, the output disk 5 and a ball held between both these disks. A cam groove 31 is installed on the back of the output disk 5 and another cam groove 32 on the back of the cam disk 21 in the tangential direction of a virtual circle 33, respectively, and both ends of each cam groove are shallowed. The ball is correctly held in a position aright owing to the groove alone, so a retainer or the like becomes disused, thus the structure is simplified as a whole.
MATSUOKA AKIO