Single phase brushless motor

Patent metadata

Field	Value
Publication number	US-10110102-B2
Application number	US-201514965303-A
Country	US
Kind code	B2
Filing date	Dec 10, 2015
Priority date	Dec 11, 2014
Publication date	Oct 23, 2018
Grant date	Oct 23, 2018

Abstract

A single phase brushless motor includes a stator and a rotor. The stator includes a stator core and stator windings wound on the stator core. The stator core includes a yoke portion, and first and second pole portions extending inwardly from the yoke portion. An end surface of the first pole portion includes a first arc surface having a first groove. An end surface of the second pole portion includes a second arc surface having a second groove. The first and second arc surfaces are opposed to each other and define a receiving space therebetween. The rotor includes a rotary shaft and permanent magnetic poles fixed to the rotary shaft. The permanent magnetic poles are received in the receiving space. A substantially uniform gap is formed between the first arc surface and the second arc surface and the permanent magnetic poles.

First claim

The invention claimed is:

1. A single phase brushless motor comprising:
a stator, the stator comprising a stator core and stator windings wound around the stator core, the stator core comprising a yoke portion, and a first pole portion and a second pole portion extending inwardly from the yoke portion, an end surface of the first pole portion comprising a first arc surface, the first arc surface comprising a first groove, an end surface of the second pole portion comprising a second arc surface, the second arc surface comprising a second groove, the first arc surface and the second arc surface being opposed to each other and defining a receiving space therebetween; and
a rotor, the rotor comprising a rotary shaft and permanent magnetic poles fixed to the rotary shaft, the permanent magnetic poles being received in the receiving space formed between the first arc surface and the second arc surface,
wherein major parts of the first arc surface and the second arc surface are located at a circle which is concentric with the rotor; and
wherein circumferential ends of the first pole portion and the second pole portion are connected by a magnetic bridge or separated by a slot, an angle formed between a center line of the first pole portion and a line connecting a center of the rotor and a center of the magnetic bridge or the slot being less than 90 degrees, a first slot and a second slot are formed between two circumferential ends of the first pole portion and two circumferential ends of the second pole portion to thereby separate the first and second pole portions, and the size of an opening of the first groove in a circumferential direction of the rotor is 1.5˜3 times of the circumferential width of the first and/or second slots, and/or the size of an opening of the second groove in the circumferential direction of the rotor is 1.5˜3 times of that of the first and/or second slots.

2. The single phase brushless motor according to claim 1 , wherein the yoke portion is a ring-shaped yoke portion, the first yoke portion and the second pole portion extend inwardly from the ring-shaped yoke portion, the rotor forms two permanent magnetic poles, and upon being energized, the stator windings produce two magnetic circuits passing through the rotor.

3. The single phase brushless motor according to claim 1 , wherein a first magnetic bridge and a second magnetic bridge are respectively formed between the circumferential ends of the first pole portion and the second pole portion, an angle formed between a line connecting a center of the first magnetic bridge and a center of the second magnetic bridge and the center line of the first pole portion being less than 90 degrees.

4. The single phase brushless motor according to claim 1 , wherein a uniform gap is formed between the first arc surface and the second arc surface and the rotor, a circumferential width of the first slot and the second slot is less than three times of the width of the uniform gap.

5. The single phase brushless motor according to claim 1 , wherein an angle formed between the center line of the first pole portion and a line connecting a center of the first slot and a center of the second slot is less than 90 degrees.

6. The single phase brushless motor according to claim 1 , wherein the end surface of the first pole portion further comprises a first flat surface and a second flat surface located at two circumferential ends of the first arc surface;
wherein the end surface of the second pole portion further comprises a third flat surface and a fourth flat surface located at two circumferential ends of the second arc surface;
wherein the first flat surface and the third flat surface are parallel to each other and form the first slot having a uniform width, the second flat surface and the fourth flat surface are parallel to each other and form the second slot having a uniform width, and a line connecting a center of the first slot and a center of the second slot passes through a center of the rotary shaft of the rotor.

7. The single phase brushless motor according to claim 6 , wherein the width of the first slot is equal to the width of the second slot.

8. The single phase brushless motor according to claim 1 , wherein a line connecting a center of the first groove and a center of the second groove passes through a center of the rotary shaft of the rotor.

9. The single phase brushless motor according to claim 1 , wherein the stator core consists of two F-shaped components having an identical configuration, with one component forming a half of the yoke portion and the first pole portion, and the other component forming the other half of the yoke portion and the second pole portion.

10. The single phase brushless motor according to claim 1 , further comprising:
an outer housing;
an end cover disposed at one end of the outer housing;
a support bracket mounted in the outer housing, the support bracket including an annular portion and a plurality of connecting members extending outwardly from the annular portion, the connecting members mounted to an inner surface of the outer housing such that the support bracket is spaced from the end cover by a predetermined distance.

11. The single phase brushless motor according to claim 10 , wherein the stator core is square-shaped, with an outwardly extending connecting portion formed at each vertex angle, and an inner surface of the outer housing forms corresponding receiving portions for receiving the connecting portions.

12. The single phase brushless motor according to claim 11 , wherein multiple ventilation holes are formed at opposite ends of the outer housing, and a flow passage in communication with the ventilation holes is formed between the stator core and the inner surface of the outer housing.

13. The single phase brushless motor according to claim 1 , wherein the motor further comprises a circuit board, a sensor is mounted to the circuit board at a location adjacent an axial end of the permanent magnetic poles of the rotor, the axial end of the permanent magnetic poles extends axially beyond the stator core, for cooperating with the sensor to sense a position of the rotor.

14. A single phase brushless motor comprising:
a stator, the stator comprising a stator core and stator windings wound around the stator core, the stator core comprising a yoke portion, and a first pole portion and a second pole portion extending inwardly from the yoke portion, an end surface of the first pole portion comprising a first arc surface, the first arc surface comprising a first groove, an end surface of the second pole portion comprising a second arc surface, the second arc surface comprising a second groove, the first arc surface and the second arc surface being opposed to each other and defining a receiving space therebetween; and
a rotor, the rotor comprising a rotary shaft and permanent magnetic poles fixed to the rotary shaft, the permanent magnetic poles being received in the receiving space formed between the first arc surface and the second arc surface,
wherein major parts of the first arc surface and the second arc surface are located at a circle which is concentric with the rotor;
wherein circumferential ends of the first pole portion and the second pole portion are connected by a magnetic bridge or separated by a slot, an angle formed between a center line of the first pole portion and a line connecting a center of the rotor and a center of the magnetic bridge or the slot being less than 90 degrees; and
wherein the stator core consists of two F-shaped components having an identical configuration, with one component forming a half of the yoke portion and

Assignees

• Johnson Electric Sa

Inventors

• Li Yue
• Zhou Chui You
• Li Gang
• Wang Yong
• Li Yong
• Zhang Wei
• Chen Ming
• Chai Jie

Classifications

• H02K1/146

  consisting of a generally annular yoke with salient poles · CPC title

• H02K1/141

  consisting of C-shaped cores · CPC title

• H02K21/225 Primary

  having I-shaped, E-shaped or similarly shaped armature cores · CPC title

• H02K17/04 Primary

  for single phase current · CPC title

• H02K9/02

  by ambient air flowing through the machine · CPC title