Rotating electric machine with various ratios for permanent magnets and holes, rotor salient and magnetic poles, rotor laminations, air gaps and stator tooth thickness

1. A rotating electric machine comprising:

a rotor boss having a plurality of soft magnetic material poles extending radially outward from the rotor boss;

a plurality of magnetic poles extending radially outward from the rotor boss and separated from the plurality of soft magnetic material poles by a circumferential gap;

a permanent magnet that is buried in each of the plurality of magnetic poles;

a yoke having a cylindrical shape that connects a plurality of teeth that are positioned along an inner periphery of the yoke and extend radially inward toward the rotor from the inner periphery of the yoke; and

a winding disposed in a slot that is defined as a space between two teeth, wherein

d0 is defined as a product of a radial thickness of the permanent magnet in millimeters and a number (p) of soft magnetic material poles,

w0 is defined as a product of a circumferential width of each soft magnetic material pole extending radially outward from the rotor boss in millimeters and the number of soft magnetic material poles, and

360 millimeters≤( w 0 2 /d 0)≤400 millimeters, and

G is defined as a circumferential width in millimeters of the circumferential gap on a circumferential edge of the rotor between each magnetic pole and each soft magnetic material pole,

B is defined as a circumferential width in millimeters of an inner end of each tooth along an inner circumferential edge of the inner end of each tooth, and

G<B.

2. The rotating electric machine of claim 1 , wherein the winding is a full-pitch winding.

3. The rotating electric machine of claim 1 , wherein

an outer diameter of the rotor is less than or equal to 60 millimeters.

4. The rotating electric machine of claim 1 , wherein

the rotating electric machine is used in a vehicular electric power steering system.

5. The rotating electric machine of claim 1 , wherein

w1 is defined as a circumferential width of each tooth at a narrowest region of a leg portion of each tooth, and

d 0/ p≥ 2 w 1.

6. The rotating electric machine of claim 5 , wherein

δ1 is defined as a length of a narrowest non-zero gap in the radial direction between the rotor and the plurality of teeth, and

2 w 1≤ d 0/ p≤ 2 w 1+δ1.

7. The rotating electric machine of claim 1 , wherein

the rotor boss, the soft magnetic material pole, and the magnetic pole are formed as a plurality of layered board members that are layered along the axial direction,

the magnetic pole has an accommodation aperture that houses the permanent magnet,

t is defined as a thickness of each of the plurality of layered board member,

w2 is defined as a circumferential width of the permanent magnet,

w3 is defined as a circumferential width of the accommodation aperture of the magnetic pole, and

w 3≤ w 2+2 t.

8. The rotating electric machine of claim 7 , wherein

w4 is defined as a circumferential width of the magnetic pole,

β is a width along a circumferential direction of a side part on ends of the accommodation aperture, the side part enclosing ends of the permanent magnet,

w 4= w 0/ p+ 2 t+ 2β, and

t≤β≤ 2 t.

9. The rotating electric machine of claim 1 , wherein

the magnetic pole has a first convex surface extending radially outward,

the soft magnetic material pole has a second convex surface extending radially outward, and

the first convex surface has a radius of curvature that is equal to a radius of curvature of the second convex surface.

10. The rotating electric machine of claim 9 , wherein

a gap between the first convex surface and the plurality of teeth and a gap between the second convex surface and the plurality of teeth are respectively smallest at a center of the circumferential width of the convex surfaces, and respectively wider toward both ends of the convex surfaces.

11. A rotor for a rotating electric machine comprising:

a rotor boss having a plurality of soft magnetic material poles extending radially outward from the rotor boss;

a plurality of magnetic poles extending radially outward from the rotor boss and separated from the plurality of soft magnetic material poles by a circumferential gap; and

a permanent magnet that is buried in each of the plurality of magnetic poles, wherein

d0 is defined as a product of a radial thickness of the permanent magnet in millimeters and a number (p) of soft magnetic material poles,

w0 is defined as a product of a circumferential width of each soft magnetic material pole extending radially outward from the rotor boss in millimeters and the number of soft magnetic material poles, and 360 millimeters≤(w0 2 /d0)≤400 millimeters.

12. A rotor for a rotating electric machine comprising:

a rotor boss;

a first plurality of salient magnetic poles that are soft magnetic material poles extending radially outward from the rotor boss; and

a second plurality of salient magnetic poles extending radially outward from the rotor boss, separated from the plurality of soft magnetic material poles by a circumferential gap and with a permanent magnet buried in each of the second plurality of salient magnetic poles, wherein

d0 is defined as a product of a radial thickness of the permanent magnet in millimeters and a number (p) of soft magnetic material poles,

w0 is defined as a product of a circumferential width of each soft magnetic material pole in millimeters and the number of soft magnetic material poles, and

360 millimeters≤( w 0 2 /d 0)≤400 millimeters.