Abstract: An improved apparatus for transmitting a rotational power from a pulley to a drive shaft of a compressor is disclosed. A coil spring is mounted on the drive shaft to absorb a load applied to the drive shaft when power is transmitted. The coil spring is arranged to be deformed upon generation of the load. A structure that transmits the power to the coil spring is securely attached to the pulley and coupled to the coil spring with a predetermined interference.

Abstract: A fluidic apparatus includes a pulley driven by an engine, torque limiting means disposed in the pulley and adapted to shut off the transmission of driving force transmitted by the pulley when overload is applied thereto, and a driving shaft driven by the torque limiting means. The torque limiting means includes a boss formed coaxially with the pulley, a collar disposed integrally and coaxially with the driving shaft, and a coiled spring adapted to hold outer peripheral surfaces of the boss and the collar by tightening with a predetermined tightening allowance. With the torque limiting means, if abnormal loads should be applied to the driving shaft, there hardly occur internal breakages, or the like, in the fluidic apparatus. In addition, because the torque limiting means has such a simple construction, the fluidic apparatus is down-sized and reduced in manufacturing cost.