US Patent 7758013 Motor-operated valve

A motor-operated valve includes a driving unit including a rotor and a stator, a feed screw mechanism, and a valve main body unit. In order to remove backlash intrinsic in the feed screw mechanism, a coil spring that urges a valve body in a direction away from a valve seat is arranged in a valve chamber. A spring bearing that forms a housing, in which the coil spring is housed, in the valve chamber is provided. Therefore, the large valve chamber is secured in the valve main body unit and passing sound is reduced when a fluid passes the motor-operated valve. Contact surfaces of the valve body and the coil spring can be aligning curved surfaces that absorb a bend of the coil spring.