Power transmitting mechanism

A power transmitting mechanism for transmitting power from an external drive source to a drive shaft of a compressor, comprising:

• a pulley;
• a hub connected to the drive shaft, which is coaxial to the pulley and is driven by the pulley;
• a coupler for connecting the pulley to the hub such that the coupler uncouples when the torque transmitted by the coupler exceeds a predetermined value, wherein the coupler includes a first coupling member, which is formed on the pulley, and a second coupling member, which is formed on the hub, wherein one of the coupling members includes an arm, a distal end of which engages the other of the coupling members, wherein when the arm is disengaged from the other of the coupling members, the distal end moves in a generally radial direction of the rotors to be kept in a non-interfering position as a result of contact between the arm and the other of the coupling members.

A power transmitting mechanism comprising:

• a first rotor;
• a second rotor, which is coaxial to the first rotor and is driven by the first rotor;
• a coupler for connecting the first rotor to the second rotor such that the coupler uncouples when the torque transmitted by the coupler exceeds a predetermined value, wherein the coupler includes a first coupling member, which is formed on the first rotor, and a second coupling member, which is formed on the second rotor, wherein one of the coupling members includes an arm, a distal end of which engages the other of the coupling members, wherein the arm is disengaged from the other of the coupling members and the distal end moves in a generally radial direction of the rotors to a non interfering position when the coupler uncouples, wherein the second coupling member includes the arm and wherein the first coupling member includes a roller and the arm includes a concave surface that engages the roller.