Patent ID: 7582993

Claim:
A motor having a reverse-rotation preventing unit, comprising: a casing; a stator fixedly-coupled to an inside of the casing; a primary rotor rotatably inserted into the stator; a motor shaft coupled to the primary rotor; a secondary rotor having a permanent magnet and rotatably inserted into an air gap between the stator and the primary rotor; a locking unit installed at an inner wall of the casing; a ratchet unit rotatably coupled to the secondary rotor, and locked or unlocked to/from the locking unit when the secondary rotor is forward-rotated or reverse-rotated, for rotating the secondary rotor in a forward direction; and a position setting unit that moves the ratchet unit using a restoration force to a locked position when the secondary rotor is stationary, and moves the ratchet unit to an unlocked position when the secondary rotor is rotating using a centrifugal force generated by the rotation of the secondary rotor.