Granted Patent B2

US 12,272,994 · App. 17/320,952 · Granted Apr 8, 2025

Inventor: Yuki Takahashi (Kariya, JP)

Assignee: DENSO CORPORATION

H02K1/28H02K1/2791H02K21/22H02K2213/03

Abstract

Claims (85)

1. A rotating electrical machine comprising:

a field generator that includes a magnet unit, the magnet unit having a plurality of magnetic poles whose polarities are alternately arranged in a circumferential direction; and

an armature that includes a multi-phase armature winding, one of the field generator and the armature serving as a rotor of the rotating electrical machine, wherein:

the magnet unit comprises:

a plurality of magnets arranged in the circumferential direction; and

a holder member that is made of a magnetic material and has a plurality of magnet installation holes in which the magnets are respectively installed;

each of the magnet installation holes is formed to be in conformity with a radial cross-sectional shape of a corresponding one of the magnets to be installed therein;

each of the magnets and the corresponding magnet installation holes has opposite peripheral surfaces, one of the opposite peripheral surfaces serving as a far-stator peripheral surface located to be farther from the stator than the other of the opposite peripheral surfaces;

the far-stator peripheral surface of each of the magnets and the corresponding magnet installation holes has a circumferential end and a circumferential middle;

the magnet unit has a first radial dimension defined from the circumferential end of the far-stator peripheral surface to the stator, and a second radial dimension defined from the circumferential middle of the far-stator peripheral surface to the stator;

the first radial dimension is less than the second radial dimension;

each of the magnets has a d-axis side region on or adjacent to a corresponding d-axis and a q-axis side region adjacent to a corresponding q-axis, the d-axis of each of the magnets being a center of a corresponding one of the magnetic poles, the q-axis being a boundary between a corresponding adjacent pair of the magnetic poles;

each of the magnets has a first length in the circumferential direction and a second length in a corresponding radial direction, the first length being longer than the second length;

each of the magnets is magnetically oriented to have:

a first set of easy axes of magnetization formed in the d-axis side region and arranged to intersect with the radial direction;

a second set of easy axes of magnetization formed in the q-axis side region and arranged to intersect with the radial direction, the easy axes of magnetization formed in the d-axis side region being more parallel to the d-axis than the easy axes of magnetization formed in the q-axis side region;

first magnetic paths created along the respective easy axes of magnetization formed in the d-axis side region; and

second magnetic paths created along the respective easy axes of magnetization formed in the q-axis side region; and

each adjacent pair of the magnets is separated from one another with respect to a corresponding one of the d-axes or a corresponding one of the q-axes.

2. The rotating electrical machine according to claim 1 , wherein:

each of the magnets and the corresponding magnet installation holes has corners formed on the far-stator peripheral surface, each of the corners formed on the far-stator peripheral surface having an obtuse interior angle.

3. The rotating electrical machine according to claim 1 , wherein:

every corner of each of the magnets is rounded.

4. The rotating electrical machine according to claim 1 , wherein:

the circumferential end of the far-stator peripheral surface of each of the magnets and the corresponding magnet installation holes has an inclined surface formed thereat, the inclined surface formed at the circumferential end of the far-stator peripheral surface of each of the magnets and the corresponding magnet installation holes being radially inclined toward the armature.

5. The rotating electrical machine according to claim 1 , wherein:

the far-stator peripheral surface of each of the magnets and the corresponding magnet installation holes is shaped as a curved surface.

6. The rotating electrical machine according to claim 1 , wherein:

the holder member has a cylindrical shape;

the magnet unit has radial thicknesses from a far-stator peripheral surface of the holder member to the far-stator peripheral surface of each of the magnet installation holes;

each of the magnets has radial thicknesses; and

a minimum of the radial thicknesses of the magnet unit is larger than or equal to half a maximum of the radial thicknesses of each magnet.

7. The rotating electrical machine according to claim 1 , wherein:

the magnet installation holes of the holder member are arranged in the circumferential direction;

the holder member is comprised of radial wall portions, each of the radial wall portions being arranged between a corresponding adjacent pair of the magnet installation holes;

each of the radial wall portions has circumferential widths;

each of the magnets has circumferential widths; and

a minimum of the circumferential widths of each of the radial wall portions is less than half a maximum of the circumferential widths of each of the magnets.

8. The rotating electrical machine according to claim 1 , wherein:

each of the magnets is located on the corresponding d-axis to be symmetrical about the corresponding d-axis, and is located between the corresponding circumferentially adjacent pair of q-axes.

9. The rotating electrical machine according to claim 1 , wherein:

the easy axes of magnetization of the first set and the easy axes of magnetization of the second set formed in each of the magnets are oriented along a magnetic-orientation circular arc, the magnetic-orientation circular arc being defined to extend about a center point determined on the corresponding d-axis;

first circular-arc magnetic paths are created as the first magnetic paths along the respective easy axes of magnetization formed in the d-axis side region;

second circular-arc magnetic paths are created as the second magnetic paths along the respective easy axes of magnetization formed in the q-axis side region; and

each of the magnets is located on the corresponding q-axis to be symmetrical about the corresponding q-axis, and is located between the corresponding circumferentially adjacent pair of d-axes.

10. The rotating electrical machine according to claim 1 , wherein:

each of the magnets is located between the corresponding circumferentially adjacent pair of d- and q-axes; and

the magnet unit has a third radial dimension from a far-stator surface of the magnet unit to the stator through the q-axis side region of each magnet, and the magnet unit has a fourth radial dimension defined from the far-stator surface of the magnet unit to the stator through a circumferential middle of the corresponding magnet,

the third radial dimension being less than the fourth radial dimension.

11. The rotating electrical machine according to claim 1 , wherein:

the holder member has a cylindrical shape;

the magnet installation holes of the holder member are arranged in the circumferential direction;

the magnet unit has:

first radial thicknesses from a far-stator peripheral surface of the holder member to the far-stator peripheral surface of each of the magnet installation holes; and

second radial thicknesses from a near-stator peripheral surface of the holder member to a near-stator peripheral surface of each of the magnet installation holes;

each of the magnets has radial thicknesses thereof;

a minimum of the first radial thicknesses and the second radial thicknesses is less than half a maximum of the radial thicknesses of each magnet;

the holder member is comprised of radial wall portions, each of the radial wall portions being arranged between a corresponding adjacent pair of the magnet installation holes;

each of the radial wall portions has circumferential widths;

each of the magnets has circumferential widths; and

a minimum of the circumferential widths of each of the radial wall portions is less than half a maximum of the circumferential widths of each of the magnets.

12. The rotating electrical machine according to claim 1 , wherein:

each of the magnets has an intrinsic coercive force of not less than 400 [kA/m] and a remanent flux density of not less than 1.0 [T].

13. The rotating electrical machine according to claim 1 , wherein:

the multi-phase armature winding includes a plurality of conductive members that face the field generator and are arrayed at given intervals away from each other in the circumferential direction; and

the armature has any one of a first configuration and a second configuration,

the first configuration having inter conductor members, each of the inter conductor members being disposed between a corresponding adjacent pair of the conductive members of the multi-phase armature winding,

the second configuration having no inter conductor member between each adjacent pair of the conductive members of the multi-phase armature winding,

each of the inter conductor members being made of any one of a magnetic material and a non-magnetic material,

the magnetic material satisfying the following relation:

Wt×Bs≤Wm×Br

where:

Wt represents a total circumferential width of one or more of the inter conductor members lying within a range of one of the magnetic poles of the magnet unit;

Bs represents a saturation magnetic flux density of the inter conductor members;

Wm represents a circumferential width of a portion of the magnet unit equivalent to one of the magnetic poles of the magnet unit; and

Br represents a remanent flux density of the magnet unit.

14. The rotating electrical machine according to claim 1 , wherein:

the multi-phase armature winding includes a plurality of conductive members that face the field generator and are arrayed at given intervals away from each other in the circumferential direction; and

each of the conductive members has a radial thickness that is smaller than a circumferential width of a portion of the armature winding, the portion of the armature winding lying in a region of a corresponding one of the magnetic poles and serving as one of the multi-phases of the armature winding.

15. The rotating electrical machine according to claim 1 , wherein:

the multi-phase armature winding includes a plurality of conductive members that face the field generator and are arrayed at given intervals away from each other in the circumferential direction;

each of the conductive members comprises a plurality of conductors;

each of the conductors is made of a collection of wires;

the wires have a first resistance therebetween; and

each of the wires has a second resistance within itself, the first resistance being larger than the second resistance.

Assignments (1)

Priority Claims (1)

Continuity (2)

References Cited (24)