Stepping motor and motorized valve using it

Patent metadata

Field	Value
Publication number	US-9525373-B2
Application number	US-201414167021-A
Country	US
Kind code	B2
Filing date	Jan 29, 2014
Priority date	Feb 19, 2013
Publication date	Dec 20, 2016
Grant date	Dec 20, 2016

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.

First claim

What is claimed is:

1. A stepping motor motorized valve comprising;
a valve main body having a valve chamber and a valve port opening to the valve chamber,
a valve body disposed movably up and down in the valve chamber for opening and closing the valve port, said valve body being driven by a stepping motor,
the stepping motor comprising a stator and a rotor rotationally driven by the stator, the valve body being attached to the rotor,
a detection rotor attached to the rotor for detecting a rotation position of the rotor,
wherein the detection rotor is rotatably disposed on a co-axial center with the rotor, and rotationally driven by the rotor via a rotation drive mechanism provided between the rotor and the detection rotor, and
wherein the rotation drive mechanism has a drive play angle in a rotation direction of the rotor to such an extent as to allow the detection rotor to be moved in a direction opposite to the rotation direction of the rotor, when the detection rotor is rotated by the rotor;
a conversion mechanism for converting rotational movement of the rotor of the stepping motor to the up and down movement of the valve body, and
a rotation stop mechanism for stopping the rotation of the rotor in one direction, when the rotor is rotated by the stator in said one direction and the valve body is moved up and down by the conversion mechanism to reach a predetermined position,
wherein said angle of the drive play is defined to be equal to or greater than an angle to which the rotor is attracted in a direction opposite to said one direction due to change in magnetic pole of the stator by a subsequent drive pulse signal, when rotation of the rotor in said one direction is stopped by the rotation stop mechanism.

2. The motorized valve according to claim 1 ,
wherein a can is fixed to the valve main body, and wherein the rotor and the detection rotor is provided in the can.

3. The motorized valve of claim 1 ,
wherein the rotation drive mechanism comprises a plurality of projections provided on the rotor having a predetermined angle interval in the rotation direction, and another projection provided on the detection rotor between the plurality of projections of the rotor,
wherein said drive play is constituted by said detection rotor being relatively slidable with respect to the rotor inside the predetermined angle interval in the rotation direction.

4. The motorized valve of claim 1 ,
wherein the rotation drive mechanism comprises a drive play concave portion provided on the rotor having a predetermined angle interval in the rotation direction, and a projection provided on the detection rotor, and having a top end disposed in the drive play concave portion of the rotor,
wherein said drive play is constituted by said detection rotor being relatively slidable with respect to the rotor inside the predetermined angle interval in the rotation direction.

5. The motorized valve of claim 1 ,
wherein urging force inhibiting the rotation of the detection rotor is applied in the detection rotor.

6. The motorized valve of claim 5 ,
wherein the urging force is generated by a magnetic material provided outside the detection rotor.

7. The motorized valve according to claim 1 ,
wherein the predetermined position is a position in which the valve body closes the valve port or a position in which the valve body fully opens the valve port.

Assignees

• Fujikoki Corp

Inventors

• Shimura Tomonori
• Ohuchi Tomoari

Classifications

• H02P8/24

  Arrangements for stopping (H02P8/32 takes precedence) · CPC title

• H02K37/00 Primary

  Motors with rotor rotating step by step and without interrupter or commutator driven by the rotor, e.g. stepping motors · CPC title

• H02K11/225

  Detecting coils · CPC title

• H02K11/215

  Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements · CPC title

• H02P8/38 Primary

  the fault being step-out · CPC title