# US 12,009,699 B2 · Rotor and brushless motor

> Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt

- Number: US 12,009,699 B2
- Document ID: US12009699B2
- Status: Granted
- Kind: B2
- Application number: 17/666,408
- Filed: 2022-02-07
- Published: 2022-08-11
- Granted: 2024-06-11
- Earliest claimed: 2021-02-09
- Assignees: Mabuchi Motor Co., Ltd.
- Applicants: Mabuchi Motor Co., Ltd.
- Inventors: Wataru Kusakabe
- Web page: https://patentgrep.com/patent/US12009699B2

## CPC

- H02K 1/2766: {having a flux concentration effect}
- H02K 21/16: having annular armature cores with salient poles (with homopolar co-operation H02K21/20)
- H02K 2213/03: Machines characterised by numerical values, ranges, mathematical expressions or similar information
- H02K: DYNAMO-ELECTRIC MACHINES (dynamo-electric relays H01H53/00; conversion of DC or AC input power into surge output power {H03K3/53})

## Abstract

A rotor includes a cylindrical core main body having a columnar space on a rotation center side. A plurality of magnet accommodating hole pair penetrates the core main body in an axial direction and includes a pair of magnets accommodating holes arranged in a V shape so as to be separated from each other toward one side of the core main body which is a stator side in a radial direction. A plurality of permanent magnets is fixed in the respective magnet accommodating holes. The plurality of permanent magnets come into pressure contact with the permanent magnet from the q-axis side and the other side in the radial direction. A protrusion forming space penetrates in the axial direction and extending from a side surface to the one side in the radial direction along the side surface.

## Claims

### Claim 1

A rotor, comprising:
a cylindrical core main body that includes a plurality of laminated cores having the same shape and having a columnar space formed on a rotation center side;
a plurality of magnet accommodating hole pairs that is provided to penetrate the cylindrical core main body in an axial direction, includes a pair of magnet accommodating holes arranged in a V shape to be separated from each other toward a first side of the cylindrical core main body which is a stator side in a radial direction, and is provided to be separated from each other in a circumferential direction of the cylindrical core main body;
a plurality of permanent magnets accommodated and fixed in the plurality of magnet accommodating hole pairs, respectively;
protrusions provided in the pair of magnet accommodating holes in one-to-one correspondence,
each protrusion of the protrusions protruding from (i) a q-axis side as a magnetic pole boundary and (ii) a second side of the cylindrical core main body opposite to the first side in the radial direction, in an extending direction of a side surface of a corresponding magnet accommodating hole of the pair of magnet accommodating holes on the q-axis side, and coming into pressure contact with a permanent magnet of the plurality of permanent magnets accommodated in the corresponding magnet accommodating hole from the q-axis side and the second side; and
a protrusion forming space penetrating in the axial direction and extending from the side surface to the first side in the radial direction along the side surface, wherein the protrusion forming space overlaps the protrusions and the plurality of permanent magnets in the circumferential direction.

### Claim 2 (depends on 1)

The rotor according to claim 1,
wherein a protrusion forming surface forming the protrusion forming space is connected to a further side surface on the second side in the radial direction forming the magnet accommodating hole of the pair of magnet accommodating holes.

### Claim 3 (depends on 1)

The rotor according to claim 1,
wherein a length of said each protrusion in a width direction orthogonal to the extending direction is twice or less a plate thickness of one laminated core.

### Claim 4 (depends on 3)

The rotor according to claim 3,
wherein the length of said each protrusion in the width direction is equal to or greater than the plate thickness.

### Claim 5 (depends on 1)

The rotor according to claim 1,
wherein a length of said each protrusion in the extending direction is longer than a length of said each protrusion in a width direction orthogonal to the extending direction.

### Claim 6 (depends on 1)

The rotor according to claim 1,
wherein the rotor is disposed on a radially inner side of the stator, and
the first side in the radial direction is a radially outer side and the second side in the radial direction is the radially inner side.

### Claim 7 (depends on 6)

A brushless motor comprising:
the rotor according to claim 6;
a shaft configured to rotate integrally with the rotor; and
the stator that is fixed to a housing, has a space in which the rotor is disposed on an inner diameter side, and has a coil.

### Claim 8 (depends on 1)

The rotor according to claim 1, wherein
the side surface extends from the first side to the second side of the cylindrical core main body.

### Claim 9 (depends on 1)

The rotor according to claim 1, wherein
said each protrusion is between the protrusion forming space and the corresponding magnet accommodating hole in the circumferential direction.
