Embedded magnet motor and rotor of embedded magnet motor

Patent metadata

Field	Value
Publication number	US-9997969-B2
Application number	US-201514879284-A
Country	US
Kind code	B2
Filing date	Oct 9, 2015
Priority date	Oct 16, 2014
Publication date	Jun 12, 2018
Grant date	Jun 12, 2018

Abstract

An embedded magnet motor includes a stator core, a plurality of permanent magnets each having a rectangular cross section, and a rotor core. The stator core and the rotor core define a first air gap being positioned at an intermediate portion of the rotor core, a second air gap being positioned at a first portion corresponding to a first axis of the rotor core, and a third air gap being positioned at a second portion corresponding to a second axis of the rotor core. Because a diameter of the intermediate portion being positioned between the first portion and the second portion of the rotor core is set smaller than a diameter of the first portion and than a diameter of the second portion, the first air gap is set greater than the second air gap and than the third air gap.

First claim

The invention claimed is:

1. An embedded magnet motor, comprising:
a stator core;
a plurality of permanent magnets each having a rectangular cross section; and
a rotor core being provided so as to face the stator core, the rotor core being embedded with the permanent magnets; wherein
the stator core and the rotor core define a first air gap being positioned at an intermediate portion of the rotor core, the first gap being positioned between the stator core and the rotor core;

the stator core and the rotor core define a second air gap being positioned at a first portion corresponding to a first axis of the rotor core, the second air gap being positioned between the stator core and the rotor core;
the stator core and the rotor core define a third air gap being positioned at a second portion corresponding to a second axis of the rotor core, the third air gap being positioned between the stator core and the rotor core; and
on a basis of the first axis being extended in a same direction as a main magnetic flux and the second axis serving as a direction electrically orthogonal to the first axis, because a diameter of the intermediate portion being positioned between the first portion and the second portion of the rotor core is set smaller than a diameter of the first portion and than a diameter of the second portion, the first air gap is set greater than the second air gap and than the third air gap,
wherein the first axis serves as a direction along the diameter of the rotor core, the direction that passes through a center of the permanent magnet;
wherein the second axis serves as a direction along the diameter of the rotor core, the direction that passes through a middle portion of the rotor core, the middle portion being positioned between the permanent magnets that are positioned next to each other,
wherein the stator core includes a plurality of teeth being provided with a wound portion that is wound with a winding wire; and
wherein the second portion includes a third portion corresponding to a magnetic path, the third portion having a width that is positioned along a tangential direction of an outer circumference of the rotor core, the width being constant or substantially constant along a diameter direction of the rotor core, and the width that s constant or substantially constant being equal to or greater than 20 percent and equal to or less than 32 percent of a width of the wound portion of the teeth of the stator core.

2. The embedded magnet motor according to claim 1 , wherein the first portion serves as a portion that includes the first axis and that has a constant diameter; and the second portion serves as a portion that includes the second axis and that has a constant diameter.

3. The embedded magnet motor according to claim 1 , wherein the stator core includes a plurality of teeth, the teeth being provided with a distal end portion; the first portion serves as a portion that includes the first axis and that has a constant diameter, and the first portion having the constant diameter has a width being positioned in a tangential direction of an outer circumference of the rotor core, the width being set smaller than a width of the distal end portion of the teeth of the stator core, the width being positioned along the tangential direction.

4. The embedded magnet motor according to claim 1 , wherein the rotor core includes a plurality of clearances, each clearance is positioned at a portion where the permanent magnet is embedded, is provided outwardly in a circumferential direction of the rotor core, and is for preventing the permanent magnet from being demagnetized; and the third portion being sandwiched by the clearances.

5. The embedded magnet motor according to claim 1 , wherein the stator core includes a plurality of teeth, the teeth being provided with a distal end portion; and the third portion being positioned in the tangential direction of the outer circumference of the rotor core, the width of the third portion is greater than a width of a protrusion protruding in a peripheral direction of the distal end portion of the teeth of the stator core, the width of the protrusion being positioned in the tangential direction.

6. The embedded magnet motor according to claim 1 , wherein the intermediate portion is V-shaped, the V-shaped intermediate portion including a base portion being provided at an inner portion of the intermediate portion in a diameter direction of the rotor core, the base portion having an angle that is an obtuse angle when seen from an axial direction of the rotor core.

7. The embedded magnet motor according to claim 1 , wherein the intermediate portion is a first intermediate portion, and the first intermediate portion and a second intermediate portion are provided at a first side and a second side in a circumferential direction of the first portion of the rotor core, respectively.

8. The embedded magnet motor according to claim 1 , wherein
the first portion serves as a portion that includes the first axis and that is positioned from the first axis to the intermediate portion of the rotor core; and
the second portion serves as a portion that includes the second axis and that is positioned from the second axis to the intermediate portion of the rotor core.

9. The embedded magnet motor according to claim 1 , wherein
the second portion includes a diameter that is greater than the diameter of the first portion of the rotor core.

Assignees

• Aisin Seiki
• Aisin Sieki Kk

Inventors

• Tsuzuki Takanori
• Miyata Daisuke

Classifications

• H02K2201/03

  Machines characterised by aspects of the air-gap between rotor and stator · CPC title

• H02K2213/03

  Machines characterised by numerical values, ranges, mathematical expressions or similar information · CPC title

• H02K29/03

  with a magnetic circuit specially adapted for avoiding torque ripples or self-starting problems · CPC title

• H02K1/276 Primary

  Magnets embedded in the magnetic core, e.g. interior permanent magnets [IPM] · CPC title