Electric machine

Patent metadata

Field	Value
Publication number	US-9647499-B2
Application number	US-201314374093-A
Country	US
Kind code	B2
Filing date	Jan 21, 2013
Priority date	Jan 23, 2012
Publication date	May 9, 2017
Grant date	May 9, 2017

Abstract

An electric machine, especially a transversal flux machine, the stator being composed of a stack of phase segments, each phase segment having at least one stator segment and one stator winding, especially a single winding, each stator segment having an annular stator bridge, on which pole shoes are premolded, which in particular extend radially inward, and/or which extend in the direction of the rotor and/or which are situated between the rotor and the annular stator bridge, the pole shoes having the same shape, in particular, the axial width of the pole shoe decreasing with increasing radial clearance, the associated profile being disposed between a first and a second profile, the first profile being a linear function of the radial clearance, the pole back associated with the first profile being a planar area, in particular, the second profile being a circular function, in particular a circular segment function, the pole back associated with the second profile being a cylindrical section area, in particular.

First claim

The invention claimed is:

1. An electric machine, comprising:
a stator including a stack of phase segments, each phase segment including at least one stator segment and at least one stator winding; and
a plurality of pole shoes, each stator segment including an annular stator bridge on which the pole shoes are premolded, the pole shoes having the same shape, wherein:
an associated profile is disposed between a first and a second profile,
the first profile is a linear function of a radial clearance,
a pole back associated with the first profile is a planar surface,
the second profile is a circular function, and
a pole back associated with the second profile is a cylindrical section area.

2. The electric machine as recited in claim 1 , wherein the electric machine is a transversal flux machine.

3. The electric machine as recited in claim 1 , wherein the at least one stator winding includes a single winding.

4. The electric machine as recited in claim 1 , wherein the pole shoes at least one of:
extend in a radially inward direction,
extend in a direction of a rotor, and
are situated between the rotor and the annular stator bridge.

5. The electric machine as recited in claim 1 , wherein an axial width of each pole shoe decreases with increasing radial clearance.

6. The electric machine as recited in claim 1 , wherein the circular function is a circular segment function.

7. The electric machine as recited in claim 1 , wherein the pole shoe has a planar design on a side thereof facing away from another stator segment in order to allow a very tight and contacting design of the stack of the phase segments.

8. The electric machine as recited in claim 5 , wherein an associated profile of the axial width as a function of the radial clearance is made up of two segments that are not parallel with each other, in which a pole back includes two planar surface pieces that are not parallel with each other.

9. The electric machine as recited in claim 8 , wherein each segment not parallel with each other is a linear function of the radial clearance.

10. The electric machine as recited in claim 5 , wherein an associated profile of the axial width as a function of the radial clearance includes a concave section and at least one of a bulbous section and a convex section, the concave section having an arc length that is at least five times shorter than the convex section.

11. The electric machine as recited in 1 , wherein an air-gap-side surface of the pole shoe includes one of an area value of the same magnitude, and an area value that differs by maximally 20% in comparison with a transition area toward the stator bridge.

12. The electric machine as recited in claim 1 , wherein the pole shoe has a pole back, the pole back at least one of at least partially facing in a direction of the stator winding and at least partially facing in a direction of the other stator segment, the pole back connecting an air-gap-side surface of the pole shoe facing a rotor, with the stator bridge, the pole back having a bulbous shape and being composed of two planar surface pieces that are not parallel with each other.

13. The electric machine as recited in claim 1 , wherein the pole shoe is formed in such a way that essentially no subregion of the pole shoe goes into saturation as long as a surface area of a side surface of the pole shoe on the side of an air gap, corresponding to a side surface facing a rotor, does not go into saturation yet.

14. The electric machine as recited in claim 1 , wherein the pole shoe has a width in a circumferential direction that increases with increasing radial clearance, wherein with the increasing radial clearance, a width in the circumferential direction increases.

15. The electric machine as recited in claim 14 , wherein the width increases in inverse proportion essentially to an extent that an axial width decreases.

16. The electric machine as recited in claim 1 , wherein at least one of:
the pole shoe is symmetrical with a plane of symmetry, the plane of symmetry running through a center of mass of the pole shoe and being defined by a radial direction starting at the center of mass, and the axial direction, and
the pole shoe is symmetrical with the plane of symmetry, the plane of symmetry running through the center of mass of the pole shoe, and a direction of a surface normal being a tangential direction at the center of mass.

17. The electric machine as recited in claim 1 , wherein an edge of the pole shoe has a broader shape in order to reduce a risk of an edge fracture.

18. The electric machine as recited in claim 1 , wherein with increasing radial clearance, an area value of a surface of intersection of the pole shoe with respect to a first area is essentially equal to an area value of an air-gap-side side surface corresponding to a side surface facing a rotor, of the pole shoe, or at least deviates by less than 10% or 20%, wherein one of:
a first surface being a tangential plane, at least one of:
which has individual radial clearance with respect to a rotor shaft axis,
which is aligned parallel to the rotor shaft axis,
which has a radial clearance,
which is aligned perpendicularly to an axis of symmetry, and
whose direction of normal connects the rotor shaft axis to a center of mass of the pole shoe, and

the first area being a cylinder sleeve area that at least one of has the individual radial clearance with respect to the rotor shaft axis and which is aligned parallel to the rotor shaft axis.

19. The electric machine as recited in claim 1 , wherein the stack is accommodated in a housing component, and wherein the housing component has an axially extending cable channel, corresponding to an axially extending depression on its surface, corresponding to an inner surface, facing the stack, wherein the housing component is connected to the stack in a force-locking manner, and wherein the housing component is one of thermally shrink-fitted and bonded.

20. The electric machine as recited in claim 1 , wherein each stator segment has two radially extending depressions, which are set apart from each other by one half of a pole shoe clearance in a circumferential direction, so that when joining two stator segments to form a phase segment, the depressions are able to be brought into congruence to form a passage for at least one of an incoming line and an outgoing line of the individual stator winding.

21. The electric machine as recited in claim 20 , wherein the depressions include slots.

22. The electric machine as recited in claim 1 , wherein the stator segment is made from pressed or sintered iron powder.

23. The electric machine as recited in claim 22 , wherein the pressed or sintered iron powder includes SMC.

24. A method for producing an electric machine comprising:
a stator including a stack of phase segments, each phase segment including at least one stator segment and at least one stator winding; and
a plurality of pole shoes, each stator segment including an annular stator bridge on which the pole shoes are premolded, the pole shoes having the same shape, wherein:
an associated profile is disposed between a first and a second profile,
the first profile is a linear function of a radial clearance,
a pole back associated with the first profile is a planar surface,
the second profile is a circular function, and
a pole back associated with the second profile is a cylindrical section area, the method comprising:

Assignees

• Sew Eurodrive Gmbh & Co Kg

Inventors

• Dreher Florian

Classifications

• H02K1/02

  characterised by the magnetic material · CPC title

• H02K2201/12

  Transversal flux machines · CPC title

• H02K37/14

  with magnets rotating within the armatures · CPC title

• H02K15/022

  with salient poles · CPC title

• H02K1/145 Primary

  having an annular coil, e.g. of the claw-pole type · CPC title