Abstract: A female screw member includes a female screw part with a female screw, and a projection part projecting in the direction of a center shaft of the female screw and having a working face in the rotating direction centering on the center shaft. The female screw part and projection part are integrally molded with a resin. The projection part has a spiral inclination face spirally inclining by one round from the working face centering on the center shaft of the female screw. The height H of the working face is equal to or smaller than a pitch P of the female screw. Using the projection part as a fully opening fixing stopper, a motor operated valve includes a valve main body having a valve seat, the female screw member attached to the valve main body, a motor having a rotator and stator, and a valve shaft. The valve shaft is screwed to a female screw of the female screw member, and is rotated and driven by the rotor, and has a fully opening movable stopper capable of contacting the fully opening fixing stopper.

Abstract: To provide a stepping motor which can precisely and reliably detect stopping of a rotor with respect to a stopper with a simple structure, i.e., positioning of a base point of the rotor, and provide a motorized valve using it. The stepping motor includes a stator 55 and a rotor 57 rotationally driven by the stator 55, and a detection rotor 47 detecting a rotation position of the rotor 57. The detection rotor 47 is rotatably disposed on a co-axial center L with the rotor 57 and rotationally driven via a rotation drive mechanism between the rotor 57 and the detection rotor 47. The rotation drive mechanism has a drive play having a predetermined length or angle in the rotation direction.

Abstract: A female screw member includes a female screw part with a female screw, and a projection part projecting in the direction of a center shaft of the female screw and having a working face in the rotating direction centering on the center shaft. The female screw part and projection part are integrally molded with a resin. The projection part has a spiral inclination face spirally inclining by one round from the working face centering on the center shaft of the female screw. The height H of the working face is equal to or smaller than a pitch P of the female screw. Using the projection part as a fully opening fixing stopper, a motor operated valve includes a valve main body having a valve seat, the female screw member attached to the valve main body, a motor having a rotator and stator, and a valve shaft. The valve shaft is screwed to a female screw of the female screw member, and is rotated and driven by the rotor, and has a fully opening movable stopper capable of contacting the fully opening fixing stopper.

Abstract: To provide a stepping motor which can precisely and reliably detect stopping of a rotor with respect to a stopper with a simple structure, i.e., positioning of a base point of the rotor, and provide a motorized valve using it. The stepping motor includes a stator 55 and a rotor 57 rotationally driven by the stator 55, and a detection rotor 47 detecting a rotation position of the rotor 57. The detection rotor 47 is rotatably disposed on a co-axial center L with the rotor 57 and rotationally driven via a rotation drive mechanism between the rotor 57 and the detection rotor 47. The rotation drive mechanism has a drive play having a predetermined length or angle in the rotation direction.

Abstract: A female screw member includes a female screw part with a female screw, and a projection part projecting in the direction of a center shaft of the female screw and having a working face in the rotating direction centering on the center shaft. The female screw part and projection part are integrally molded with a resin. The projection part has a spiral inclination face spirally inclining by one round from the working face centering on the center shaft of the female screw. The height H of the working face is equal to or smaller than a pitch P of the female screw. Using the projection part as a fully opening fixing stopper, a motor operated valve includes a valve main body having a valve seat, the female screw member attached to the valve main body, a motor having a rotator and stator, and a valve shaft. The valve shaft is screwed to a female screw of the female screw member, and is rotated and driven by the rotor, and has a fully opening movable stopper capable of contacting the fully opening fixing stopper.

Abstract: To provide a motor-driven valve with a small number of parts, with excellent assemblage, capable of maintaining a large valve port diameter even downsized, and to prevent deterioration of housing environment due to sound caused by the impact and shortened life that are generated by collisions of closing limit stopper parts.

Abstract: To improve methods of manufacturing a rotor core, a rotor feed screw, and a rotor for motor-driven valves and reduce manufacturing cost of the motor-driven valves.

Abstract: A female screw member includes a female screw part with a female screw, and a projection part projecting in the direction of a center shaft of the female screw and having a working face in the rotating direction centering on the center shaft. The female screw part and projection part are integrally molded with a resin. The projection part has a spiral inclination face spirally inclining by one round from the working face centering on the center shaft of the female screw. The height H of the working face is equal to or smaller than a pitch P of the female screw. Using the projection part as a fully opening fixing stopper, a motor operated valve includes a valve main body having a valve seat, the female screw member attached to the valve main body, a motor having a rotator and stator, and a valve shaft. The valve shaft is screwed to a female screw of the female screw member, and is rotated and driven by the rotor, and has a fully opening movable stopper capable of contacting the fully opening fixing stopper.

Abstract: To provide a motor-driven valve with a small number of parts, with excellent assemblage, capable of maintaining a large valve port diameter even downsized, and to prevent deterioration of housing environment due to sound caused by the impact and shortened life that are generated by collisions of closing limit stopper parts.

Abstract: To improve methods of manufacturing a rotor core, a rotor feed screw, and a rotor for motor-driven valves and reduce manufacturing cost of the motor-driven valves.

Abstract: Objective To avoid undesirable contact between the moving side stopper and the fixed side stopper, to maximize the contact width at the time of hitting, to decrease damages, wearing, etc. to those stoppers, and to improve reliability of the moving side stopper and the fixed side stopper in terms of rigidity and durability. Solution To provide a motor operated valve comprising a valve body 20, a screw fed valve stem 30 and a shaft 35, a motor 10 which rotationally drive the aforementioned shaft 35, a sleeve 40 having a convexed moving side stopper 41 which is rotated with the aforementioned shaft 35 as a monolithic structure, and a fixed bearing washer having a convexed fixed side stopper 55 to which the aforementioned moving side stopper 41 hits, and where a clearance slope 41a to avoid hitting the fixed side stopper 55 is provided on the rear part, looking in the rotational direction, of the aforementioned moving side stopper 41.