Rotating electric machine

Patent metadata

Field	Value
Publication number	US-12003139-B2
Application number	US-202117411304-A
Country	US
Kind code	B2
Filing date	Aug 25, 2021
Priority date	Feb 25, 2019
Publication date	Jun 4, 2024
Grant date	Jun 4, 2024

Abstract

The rotating electric machine includes a stator having a stator winding and a rotor facing the stator in a radial direction. The rotor includes a carrier having a disk-shaped end plate section fixed to a rotating shaft and arranged coaxially with the rotating shaft, and an annular magnet unit arranged coaxially with the rotating shaft. The magnet has a cylindrical magnet holder whose one end in an axial direction is fixed to the end plate section, and a magnet fixed to a peripheral surface on a stator side in the radial direction in the magnet holder and having an alternating polarity in a circumferential direction. The magnet holder is made of a non-magnetic material. In the magnet, an orientation of an axis of easy magnetization on a q-axis is deviated from an orientation parallel to the q-axis.

First claim

What is claimed is:

1. A rotating electric machine comprising:
a stator having a stator winding; and
a rotor facing the stator in a radial direction, wherein
the rotor includes: a carrier having a disk-shaped end plate section fixed to a rotating shaft and arranged coaxially with the rotating shaft; and an annular magnet unit arranged coaxially with the rotating shaft,
the magnet unit includes a cylindrical magnet holder of which one end in an axial direction is fixed to the end plate section; and a magnet fixed to a peripheral surface on a stator side in the radial direction in the magnet holder and having an alternating polarity in a circumferential direction,
the magnet holder is made of a non-magnetic material having a specific gravity smaller than a specific gravity of iron,
in the magnet, an orientation of an axis of easy magnetization on a q-axis is deviated from an orientation parallel to the q-axis,
the carrier is made of a magnetic material,
the end plate section and the magnet are separated by a first distance in the axial direction,
the stator has a cylindrical stator core assembled on an opposite-to-rotor side in the radial direction in the stator winding, and
a second distance in the radial direction between the peripheral surface of the stator core on a side facing the rotor and the peripheral surface of the magnet on a side facing the stator is smaller than the first distance.

2. The rotating electric machine according to claim 1 , wherein
the magnet unit has an end plate fixed on both sides of the holder in the axial direction opposite to the carrier, and
the end plate is made of a non-magnetic material.

3. The rotating electric machine according to claim 2 , wherein the end plate is made of a non-magnetic material having a specific gravity greater than a specific gravity of the holder.

4. The rotating electric machine according to claim 1 , wherein
the rotor is arranged outside the stator in the radial direction,
the magnet unit has a cylindrical outer holder fixed to an outer peripheral surface of the magnet holder, and
a strength of the outer holder is higher than a strength of the magnet holder.

5. The rotating electric machine according to claim 1 , wherein a thickness dimension in the radial direction of the magnet is equal to or less than an arc length of a magnetic flux transfer surface between d-q axes.

6. The rotating electric machine according to claim 5 , wherein in the magnet, when an intersection of the q-axis and the magnetic flux transfer surface is a center point and a circle whose radius is a radial thickness dimension of the magnet is an orientation circle that defines the axis of easy magnetization of the magnet, the magnet covers a quarter circle of the orientation circle.

7. The rotating electric machine according to claim 1 , wherein the magnet is oriented so as to have a linear axis of easy magnetization tilted with respect to a d-axis.

Assignees

• Denso Corp

Inventors

• Tsuchiya Hiroyuki
• Koda Shinji
• Takahashi Yuki
• Iwase Kazuya
• Tamura Akito

Classifications

• H02K1/2766 Primary

  having a flux concentration effect · CPC title

• H02K1/2791

  Surface mounted magnets; Inset magnets · CPC title

• H02K3/47 Primary

  Air-gap windings, i.e. iron-free windings · CPC title

• H02K11/33

  Drive circuits, e.g. power electronics (H02K11/38 takes precedence) · CPC title

• H02K2213/03

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