Stepping motor and system thereof

Patent metadata

Field	Value
Publication number	US-9293976-B2
Application number	US-201414291220-A
Country	US
Kind code	B2
Filing date	May 30, 2014
Priority date	Sep 17, 2013
Publication date	Mar 22, 2016
Grant date	Mar 22, 2016

Abstract

A stepping motor includes a housing, a stator assembly, a rotor, and a sensor portion. The stator assembly is disposed inside the housing. The rotor is rotatably disposed inside the stator assembly and includes a rotation shaft, and opposite ends of the rotation shaft are supported by the housing. The sensor portion is disposed inside the housing and detects a magnetic field of the rotor.

First claim

What is claimed is:

1. A stepping motor comprising:
a housing;
a stator assembly disposed inside the housing;
a rotor that is rotatably disposed inside the stator assembly and includes a rotation shaft, and opposite ends of the rotation shaft are supported by the housing; and
a sensor portion that is disposed inside the housing and detects a magnetic field of the rotor,
wherein the sensor portion is disposed at a position that is spaced apart from the top end of the rotor, and the position is at an intersection of a center line of an upper pole piece of an upper yoke of the stator assembly, a straight line passing through a center of the rotor, and a tangent line of an outer diameter of the rotor.

2. The stepping motor of claim 1 , wherein the sensor portion comprises a magneto resistive sensor.

3. The stepping motor of claim 2 , wherein the magneto resistive sensor is disposed above a top end of the rotor.

4. The stepping motor of claim 2 , wherein:
the rotor comprises an upper rotor disposed on the rotation shaft and a lower rotor that is spaced apart from the upper rotor and is disposed on the rotation shaft coaxially with
the upper rotor; and
the magneto resistive sensor is disposed in a space between the upper rotor and the lower rotor.

5. The stepping motor of claim 2 , wherein the sensor portion further comprises a support portion to support the magneto resistive sensor.

6. The stepping motor of claim 1 , wherein the sensor portion comprises two magneto resistive sensors that are arranged with a 90 degree phase difference.

7. The stepping motor of claim 1 , wherein the sensor portion comprises a Hall sensor.

8. A stepping motor system comprising:
a stepping motor, wherein the stepping motor comprises:
a housing;
a stator assembly disposed inside the housing;
a rotor that is rotatably disposed inside the stator assembly and includes a rotation shaft, and opposite ends of the rotation shaft are supported by the housing; and
a sensor portion that is disposed inside the housing and detects a magnetic field of the rotor, wherein the sensor portion is disposed at a position that is spaced apart from the top end of the rotor, and the position is at an intersection of a center line of an upper pole piece of an upper yoke of the stator assembly, a straight line passing through a center of the rotor, and a tangent line of an outer diameter of the rotor; and
a controller configured to control the stepping motor, wherein the controller comprises:
a step-out determination unit configured to determine whether a step-out phenomenon of the stepping motor has occurred by receiving a signal from the sensor portion; and
a driving unit configured to drive the stepping motor.

9. The stepping motor system of claim 8 , wherein when the step-out determination unit detects a step-out phenomenon of the stepping motor, the controller controls the driving unit to increase a driving force of the stepping motor.

10. The stepping motor system of claim 8 , wherein the sensor portion comprises a magneto resistive sensor or a Hall sensor.

11. The stepping motor system of claim 10 , wherein the magneto resistive sensor is disposed above the rotor.

12. The stepping motor system of claim 10 , wherein:
the rotor comprises an upper rotor disposed on the rotation shaft and a lower rotor that is spaced apart from the upper rotor and is disposed on the rotation shaft coaxially with the upper rotor, and
the magneto resistive sensor is disposed in a space between the upper rotor and the lower rotor.

13. The stepping motor system of claim 10 , wherein the sensor portion further comprises a support portion to support the magneto resistive sensor.

14. The stepping motor system of claim 8 , wherein the sensor portion comprises two magneto resistive sensors that are arranged with a 90 degree phase difference.

Assignees

• Samsung Electronics Co Ltd

Inventors

• Lee Kun-Woo
• Shim Jae-Kyu
• Cho Woo-Jong
• Koo Bon-Min

Classifications

• 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

• H02P8/38

  the fault being step-out · CPC title

• H02K37/14

  with magnets rotating within the armatures · CPC title

• H02K11/0021

  Electricity · mapped topic

• H02K11/215 Primary

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