Motor

• US 10,396,643 B2
• Filed: 11/29/2017
• Issued: 08/27/2019
• Est. Priority Date: 11/30/2016
• Status: Active Grant

• Current Assignee: Minebea Mitsumi, Inc.
• Original Assignee: Minebea Mitsumi, Inc.
• Inventors: Suzuki, Tomohisa, Kamogi, Yutaka
• Primary Examiner(s): Hollington, Jermele M
• Assistant Examiner(s): Fortich, Alvaro E
• Application Number:
  US15/825,228
• Publication Number:
  US 20180152088A1
• Time in Patent Office: 636 Days
• CPC Class Codes: H02K 1/2733 Annular magnets
• CPC Class Codes: H02K 11/215 Magnetic effect devices, e.g. Hall-effect or magneto-resistive elements
• CPC Class Codes: H02K 29/08 using magnetic effect devices, e.g. Hall-plates, magneto-resistors H02K29/12 takes precedence
• CPC Class Codes: H02K 29/12 using detecting coils using the machine windings as detecting coil
• CPC Class Codes: H02K 5/225 Terminal boxes or connection arrangements specially adapted for submersible motors H02K5/132
• CPC Class Codes: H02P 6/16 Circuit arrangements for detecting position

Abstract

A motor includes a rotational shaft, a bearing supporting the rotational shaft, a magnet including plural magnetic poles in a circumferential direction, a rotor core disposed inside the magnet, and a magnetic sensor. The magnet includes a projection portion projecting toward a side of the bearing with respect to the rotor core in a direction of the rotational shaft. The magnetic sensor is positioned between the rotor core and the bearing in the direction of the rotational shaft and is positioned inside an inner peripheral surface of the projection portion.

Claims

1. A motor comprising:

a rotational shaft;

a bearing supporting the rotational shaft;

a magnet including plural magnetic poles in a circumferential direction;

a rotor core disposed inside the magnet; and

a magnetic sensor, wherein

the magnet includes a projection portion projecting toward a side of the bearing with respect to the rotor core in a direction of the rotational shaft, and

the magnetic sensor is positioned between the rotor core and the bearing in the direction of the rotational shaft and is positioned inside an inner peripheral surface of the projection portion.

2. The motor according to claim 1, wherein

the rotor core is a magnetic body, and

a detection surface of the magnetic sensor faces the inner peripheral surface of the projection portion.

3. The motor according to claim 2, wherein

the detection surface of the magnetic sensor is positioned between the projection portion and the rotational shaft.

4. The motor according to claim 3, wherein

the magnetic sensor is at a position away from an end portion of the projection portion and the bearing in the direction of the rotational shaft.

5. The motor according to claim 4, wherein

the magnetic sensor detects a magnetic flux in a radial direction of the magnet.

6. The motor according to claim 1, comprising:

a holder supporting the magnetic sensor; and

a housing accommodating a bracket, the bracket supporting the bearing, wherein

the holder and the bracket are lined in the direction of the rotational shaft.

7. The motor according to claim 6, wherein

the magnetic sensor includes a terminal unit extending in the direction of the rotational shaft, and

the terminal unit of the magnetic sensor is attached to the holder.

8. The motor according to claim 7, comprising a conduction terminal to be electrically connected with an exterior, wherein

the conduction terminal is attached to the holder.

9. The motor according to claim 8, wherein

the holder is formed with a single member.

10. The motor according to claim 7, comprising

plate-like members including a conductive property, wherein

the plate-like members are electrically connected with the plural terminals, and

the terminal unit of the magnetic sensor includes plural terminals, and

the respective plural plate-like members in the holder are disposed and lined in the direction of the rotational shaft.