Rotary electrical machine with configuration minimizing torque undulations

Patent metadata

Field	Value
Publication number	US-10574102-B2
Application number	US-201715468528-A
Country	US
Kind code	B2
Filing date	Mar 24, 2017
Priority date	Mar 25, 2016
Publication date	Feb 25, 2020
Grant date	Feb 25, 2020

Abstract

A rotary electrical machine comprises a stator and a rotor having an axis of rotation, wherein, on a plane radial to the axis of rotation has a rotor tooth with an arc of a circle. The arc is defined by a centre situated on the axis of symmetry of the tooth, a first point at an intersection between the axis of symmetry and a circle centred on the axis of rotation, and an outer radius. A second point is situated on an axis which passes via the axis of rotation, and forms an angle of 360° divided by a number equal to twice the number of magnetic poles. The second point is situated from the axis of rotation an amount equal to the outer radius decreased by an allowance. A ratio between the allowance and the outer radius is between 0.015 and 0.07.

First claim

The invention claimed is:

1. A rotary electrical machine ( 10 ), comprising:
a stator ( 15 ) comprising a stator body ( 16 ) provided with a number of stator teeth ( 20 ) defining a plurality of notches ( 24 ), and a stator winding ( 17 ) inserted in the notches ( 24 ); and
a rotor ( 11 ) having an axis of rotation (X) and comprising a plurality of rotor teeth ( 40 ) defining cavities ( 36 ) in which permanent magnets ( 37 ) are disposed, the rotor ( 11 ) comprising a set of magnetic poles;
the rotor ( 11 ) is contained in a cylinder of revolution with an outer radius (L 3 ), each rotor tooth ( 40 ) comprising:
an axis of symmetry (Y) passing through the axis of rotation (X) of the rotor; and
an outer face ( 42 ) opposite an inner periphery of the stator ( 15 ), on a plane (PI_R) radial relative to the axis of rotation (X);
the outer face ( 42 ) having a curvature in the form of an arc of a tooth circle, the arc of the tooth circle being defined by:
a center (O 1 ) situated on the axis of symmetry (Y);
a first point (P 1 ) situated at an intersection of the axis of symmetry (Y) and a circle centered on the axis of rotation (X), and a radius of which is the outer radius (L 3 ); and
a second point (P 2 ) situated on an axis (Z) passing through the axis of rotation (X) of the rotor, and forming an angle of 360° divided by a number equal to twice the number of magnetic poles relative to the axis of symmetry (Y);

the second point (P 2 ) being situated at a distance from the axis of rotation (X) of the rotor which is equal to the outer radius (L 3 ) decreased by an allowance (L 5 ); and
a ratio (R 3 ) of the allowance (L 5 ) to the outer radius (L 3 ) is between 0.015 and 0.07.

2. The rotary electrical machine according to claim 1 , wherein a number of notches per pole and per phase is equal to 0.5.

3. The rotary electrical machine according to claim 2 , wherein:
the stator ( 15 ) comprises a stator tooth pitch (A 1 ) equal to 360° divided by a number of the stator teeth ( 20 );
on a plane (PI_R) radial relative to the axis of rotation (X) of the rotor, a rotor tooth opening (A 2 ) is equal to an angle between two straight lines (D 1 , D 2 ) each passing via the axis of rotation (X) of the rotor and an ortho-radial end of the outer face ( 42 ); and
a ratio (R 1 ) of the rotor tooth opening (A 2 ) in degrees to the stator tooth pitch (Al) in degrees is between 0.8 and 1.2.

4. The rotary electrical machine according to claim 2 , wherein a ratio (R 2 ) of an inner diameter (L 2 ) of the stator ( 15 ) expressed in mm to a number of pairs of rotor poles (p) is between 12 and 22.

5. The rotary electrical machine according to claim 1 , wherein a ratio (R 2 ) of an inner diameter (L 2 ) of the stator ( 15 ) expressed in mm to a number of pairs of rotor poles (p) is between 12 and 22 .

6. The rotary electrical machine according to claim 1 , wherein the stator winding ( 17 ) is formed by a set of coils ( 28 ) each wound around one of the stator teeth ( 20 ).

7. The rotary electrical machine according to claim 1 , wherein the rotor ( 11 ) is fitted on a shaft ( 12 ).

8. The rotary electrical machine according to claim 1 , wherein the stator body ( 16 ) and the rotor ( 11 ) are each formed by a set of plates.

9. The rotary electrical machine according to claim 1 , wherein a number of pairs of poles is equal to five.

10. The rotary electrical machine according to claim 1 , wherein an inner diameter (L 2 ) of the stator body ( 16 ) is between 60 mm and 115 mm.

11. The rotary electrical machine according to claim 1 , wherein an outer diameter (L 8 ) of the stator body is between 100 mm and 150 mm.

12. The rotary electrical machine according to claim 1 , wherein the outer radius (L 3 ) of the cylinder of revolution (Cyl) in which the rotor ( 11 ) is disposed is substantially equal to 34 mm.

13. The rotary electrical machine according to claim 1 , wherein a rotor tooth opening (A 2 ) is approximately 24°.

14. The rotary electrical machine according to claim 1 , wherein a stator tooth opening (A 3 ) is approximately 20°.

15. The rotary electrical machine according to claim 1 , wherein each of the permanent magnets ( 37 ) has a beveled end ( 44 ) situated on a side of the axis of rotation (X).

16. The rotary electrical machine according to claim 1 , wherein the rotor ( 11 ) is of a flux concentration type.

Assignees

• Valeo Equip Electr Moteur
• Valeo Equipments Electriques Moteur

Inventors

• Legranger Jérome
• El Baraka Khadija
• Jugovic Svetislav

Classifications

• H02K1/2773 Primary

  consisting of tangentially magnetized radial magnets · CPC title

• H02K2201/03

  Machines characterised by aspects of the air-gap between rotor and stator · CPC title

• H02K3/18

  Windings for salient poles · CPC title

• H02K1/146

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

• H02K2213/03

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