Patent ID: 7303478

Claim:
A power transmission mechanism for transmitting a torque to a rotating shaft of a compressor of an air conditioner for a vehicle comprising: a rotating body having a female screw formed in a center thereof; a rotating shaft having a male screw formed on a part of an outer surface thereof and thereby being screwed into the rotating body; a pulley rotatably supported by a bearing on an outer surface of a housing of the compressor; a torque limiter located between the rotating body and the pulley, wherein the torque limiter transmits torque from the pulley to the rotating body; an end surface, in an axial direction, formed on the rotating body side as a bearing surface for transmitting a torque between the rotating body and the rotating shaft by being pressed against a bearing surface of an opposite rotating shaft side by action of the female screw and the male screw and by being brought into frictional contact therewith, and for preventing the male screw from being screwed excessively into the female screw; and an end surface, in an axial direction, formed on the rotating shaft side as the bearing surface for the same purpose, corresponding to the end surface on the rotating body side and for mating therewith; wherein the two end surfaces are arranged in opposite positions to each other; and an annular space is formed around the rotating shaft in order to form a part, near a center of at least one of the two end surfaces in frictional contact with each other, which does not come into contact with the other end surface and does not act as a bearing surface.