Patent ID: 7494108

Claim:
A motor-operated valve comprising a rotor of a motor accommodated on the inside of a can and a stator including an exciting coil disposed on the outside of the can, in which rotational motion of the rotor is converted into advance and retreat motion by a screw mechanism, by which a valve opening with respect to a valve seat of a valve element is controlled, wherein the motor-operated valve further comprises a screw feed member rotating integrally with the rotor; a stem member fixed to a valve body that accommodates the valve seat; a valve stem which is inserted slidably in the stem member to support the valve element; and an external thread member fixed to the valve stem, and the screw feed member engages threadedly with a first screw portion provided between the screw feed member and the stem member and a second screw portion provided between the screw feed member and the external thread member, and the first screw portion has a larger pitch than the second screw portion.