Deep V-magnet cavity structure rotor

Patent metadata

Field	Value
Publication number	US-9479017-B2
Application number	US-201414337820-A
Country	US
Kind code	B2
Filing date	Jul 22, 2014
Priority date	Jul 22, 2014
Publication date	Oct 25, 2016
Grant date	Oct 25, 2016

Abstract

A rotor for a permanent magnet synchronous machine. A first layer of cavities formed circumferentially within the rotor core structure. Pairs of the cavities in the first layer form V-shaped configurations and are spaced circumferentially about the rotor core structure in the first layer. A second layer of cavities is formed circumferentially within the rotor core structure. Pairs of the cavities in the second layer form V-shaped configurations and are spaced circumferentially about the rotor core structure in the second layer. A first set of permanent magnets is inserted within each cavity in the first layer and a second set of permanent magnets inserted within each cavity in the second layer. Each respective V-shaped configuration of the second layer having permanent magnets disposed therein extend greater than half a radial distance from the outer cylindrical wall to the inner cylindrical wall.

First claim

What is claimed is:

1. A rotor for a permanent magnet synchronous machine comprising:
a rotor core structure having a cylindrical body, the cylindrical body including an inner cylindrical wall and an outer cylindrical wall;
a first layer of cavities formed circumferentially within the rotor core structure, pairs of the cavities in the first layer form V-shaped configurations and are spaced circumferentially about the rotor core structure in the first layer, each V-shaped configuration includes a first leg cavity and a second leg cavity, an apex of each V-shaped configuration formed by the first leg cavity and the second leg cavity extends toward the inner cylindrical wall, and an open end of each V-shape configuration extends toward the outer cylindrical wall;
a second layer of cavities formed circumferentially within the rotor core structure, pairs of the cavities in the second layer form V-shaped configurations and are spaced circumferentially about the rotor core structure in the second layer, each V-shaped configuration of the second layer includes a first leg cavity and a second leg cavity, an apex of each V-shaped configuration in the second layer formed by the first leg cavity and the second leg cavity extends toward the inner cylindrical wall, an open end of each V-shape configuration in the second layer extends toward the outer cylindrical wall;
a first set of permanent magnets inserted within each cavity in the first layer; and
a second set of permanent magnets inserted within each cavity in the second layer, the magnetic field strength of the first set of permanent magnets is greater than the magnetic field strength of the second set of permanent magnets;
wherein each respective V-shaped cavity and associated magnets of the first layer is paired with a respective V-shaped cavity and associated magnets of the second layer to form rotor poles, wherein each respective first leg in the second layer of each respective pole is outwardly offset and parallel to an associated first leg in the first layer of each respective pole, and wherein each respective second leg in the second layer of each respective pole is outwardly offset and parallel to an associated second leg in the first layer of each respective pole, and wherein each respective V-shaped configuration of the second layer having permanent magnets disposed therein extend greater than half a radial distance from the outer cylindrical wall to the inner cylindrical wall.

2. The rotor of claim 1 wherein each respective V-shaped configuration of the second layer having permanent magnets disposed therein extends greater than three-quarters of a radial distance from outer cylindrical wall to the inner cylindrical wall.

3. The rotor of claim 1 further comprising a plurality of bridges each extending between the apex of each V-shaped configuration in the second layer and the inner cylinder wall, the plurality of bridges providing structural support of the rotor core structure when operating, wherein a width of each respective bridge determines the radial distance that each of the legs of the V-shaped configuration extend to the inner cylinder wall.

4. The rotor of claim 1 further comprising a plurality of bridges each extending between the first and second legs of each V-shaped configuration of the open end in the second layer and the outer cylinder wall, the plurality of bridges providing structural support of the rotor core structure when operating.

5. The rotor of claim 1 wherein the plurality of cavities each includes a first air gap formed between a first end of each respective magnet disposed within each of the plurality of cavities and a first distal end of each of the plurality of cavities, wherein the first distal end is closest to the inner cylinder wall, and wherein the first air gap within each of the plurality of cavities reduces demagnetization.

6. The rotor of claim 5 wherein the plurality of cavities each includes a second air gap disposed between a second end of each respective magnet disposed within each of the plurality of cavities and a second distal end of each of the plurality of cavities, wherein the second distal end is closest to the outer cylinder wall, and wherein the second air gap within each of the plurality of cavities reduces demagnetization.

7. The rotor of claim 6 wherein each of the plurality of cavities includes a first indentation formed a first predetermined distance from the first distal end of the plurality of cavities, wherein each of the plurality of cavities includes a second indentation formed a second predetermined distance from the second distal end of the plurality of cavities, and wherein the first and second indentations prevent movement of each of the permanent magnets within the plurality of cavities from moving.

8. The rotor of claim 6 wherein the first and second air gaps generates a magnetic reluctance that assists in reducing demagnetization.

9. The rotor of claim of claim 1 further comprising a plurality of interim bridges separating the first legs and the second legs at each respective apex of each V-shaped configuration in the first layer and second layers.

10. The rotor of claim 9 wherein the plurality of interim bridges maintains rotor integrity.

11. The rotor of claim 10 wherein the plurality of interim bridges limits the short-circuited flux.

12. The rotor of claim 1 wherein the V-shaped configurations of the first layer are uniformly spaced about the first layer.

13. The rotor of claim 1 wherein the V-shaped configurations of the second layer are uniformly spaced about the second layer.

14. The rotor of claim 1 wherein the first set of magnets is rare earth magnets and the second set of magnets is ferrite magnets.

15. The rotor of claim 1 wherein the first set of magnets and second set of magnets are ferrite magnets, wherein the first set of magnets generate a greater magnetic field relative to the second set of magnets.

16. The rotor of claim 1 wherein the first set of magnets and second set of magnets are rare earth magnets, wherein the first set of magnets generate a greater magnetic field relative to the second set of magnets.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Hao Lei
• Nehl Thomas W

Classifications

• H02K1/2766 Primary

  having a flux concentration effect · CPC title

• H02K1/02

  characterised by the magnetic material · CPC title

• H02K2213/03

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