A power transmission apparatus which can function as a torque limiter during an overload condition. A Belleville spring is provided for generating mutual frictional engagement in areas between a flange part integral to an inner holder member, a washer, arc shaped projections of a flange part of a hub and a washer. As a result, during a normal condition of a compressor, the rotating movement of the inner holder member located adjacent to the rotating movement source is transmitted via the frictional engagement mechanism to a hub and then to a rotating shaft. Contrary to this, during an overloaded condition, a slippage is generated in the area between the washer and the arc shaped projections of the flange part of the hub as a frictional engaging area of a lower coefficient of friction. This slippage causes the washer to sink into the recess of the hub, which causes the washer to be displaced in the direction of the axis of the rotating shaft, which causes the pressing force to be reduced in the Belleville spring, resulting in a free rotating movement of the flange part.