Electromagnetic actuator

Patent metadata

Field	Value
Publication number	US-10637317-B2
Application number	US-201715595146-A
Country	US
Kind code	B2
Filing date	May 15, 2017
Priority date	Oct 21, 2016
Publication date	Apr 28, 2020
Grant date	Apr 28, 2020

Abstract

The present disclosure provides an electromagnetic actuator that drives an armature by an electromagnetic force. The electromagnetic actuator includes a stator, a coil, and an insulator. The stator is formed of a magnetic material and has a cylindrical portion. The coil is disposed outside of the stator. The coil generates a magnetic field when being energized. The insulator is disposed in a particular region of the stator facing the coil in a radial direction. The insulator extends partially along the stator in a circumferential direction and suppresses a current flowing through the stator in the circumferential direction. The stator is continuously formed entirely along the circumferential direction by the magnetic material.

First claim

What is claimed is:

1. An electromagnetic actuator that drives an armature by an electromagnetic force, the electromagnetic actuator comprising:
a stator that is formed of a magnetic material and has a cylindrical portion;
a coil that is disposed outside of the stator, the coil generating a magnetic field when being energized; and
an insulator that extends partially along the stator in a circumferential direction and suppresses a current flowing through the stator in the circumferential direction, wherein
the stator includes a portion that is continuously formed entirely along the circumferential direction by the magnetic material,
the cylindrical portion of the stator is provided with the insulator, and
the insulator is formed of a slit extending along an axial direction of the cylindrical portion and located in a region of the stator where the stator faces the coil in a radial direction of the cylindrical portion.

2. The electromagnetic actuator according to claim 1 , further comprising:
a stopper that is formed in a pipe shape and is disposed inside the stator, the stopper being brought into contact with the armature when the armature is moved; and
a spring that is disposed inside the stopper, the spring biasing the armature, wherein
a clearance is defined between an inner wall of the stator and an outer wall of the stopper in the region where the coil faces the stator.

3. The electromagnetic actuator according to claim 1 , wherein the slit passes through a wall of the stator.

4. The electromagnetic actuator according to claim 3 , further comprising
a first resin portion that is made of a resin and is located in the slit.

5. The electromagnetic actuator according to claim 2 , further comprising a second resin portion that is formed of a resin and is disposed in the clearance.

6. The electromagnetic actuator according to claim 3 , wherein
the stator includes an end portion facing the armature,
the cylindrical portion is provided with at least two slits including the slit, and
the at least two slits each extends along the axial direction over the region and face each other in the radial direction.

7. The electromagnetic actuator according to claim 3 , wherein
the stator has a positioning portion that is recessed from an outer surface of the cylindrical portion in the radial direction, the positioning portion configured to position the coil, and
the slit is formed in the positioning portion.

8. An electromagnetic actuator that drives an armature by an electromagnetic force, the electromagnetic actuator comprising:
a stator;
a coil located outside of the stator and generating a magnetic field when being energized; and
an insulator suppressing a current flowing through the stator along a circumferential direction of the stator, wherein
the stator includes:
a first portion facing the coil in a radial direction of the stator and provided with the insulator; and
a second portion located adjacent to the first portion in an axial direction of the stator, located outside of the coil along the axial direction, and continuously formed entirely along the circumferential direction, and

the insulator is formed of a slit extending along the axial direction.

9. The electromagnetic actuator according to claim 8 , wherein
the slit extends from a distal end of the first portion toward the second portion along the axial direction.

10. The electromagnetic actuator according to claim 9 , wherein
the first portion has a hollow cylindrical shape, and
the slit passes through the first portion in the radial direction.

Assignees

• Denso Corp

Inventors

• Sassa Kazuya
• Adachi Naofumi
• Kitani Shingo

Classifications

• H02K3/30 Primary

  Windings characterised by the insulating material · CPC title

• H02K3/28

  Layout of windings or of connections between windings (windings for pole-changing H02K17/06, H02K17/14, H02K19/12, H02K19/32) · CPC title

• H02K1/34

  Reciprocating, oscillating or vibrating parts of the magnetic circuit · CPC title

• H01F2007/1676

  Means for avoiding or reducing eddy currents in the magnetic circuit, e.g. radial slots · CPC title

• F02M51/0628 Primary

  having a stepped armature · CPC title