STATOR OF A ROTATING ELECTRICAL MACHINE, ROTATING ELECTRICAL MACHINE AND DRIVE UNIT HAVING A MACHINE OF THIS TYPE

Abstract

The invention relates to a rotating electrical machine with an external rotor having a permanent magnet assembly. The invention also relates to a stator of a rotating electric machine of this type. In order to increase the performance and/or reduce the weight and/or installation space, a permanent magnet assembly is provided having segments with changing magnetisation directions in such a way that the magnetic flow is increased over the inner casing surface of the hollow cylinder facing the stator and therefore in the air gap and it is reduced over the opposing outer casing surface. For the stator of a drive unit of this type, stator teeth of a trapezoidal shape are proposed, having an outwardly increasing tooth width, wherein a respective coil winding is arranged on the stator teeth.

Claims

1-15. (canceled)

16. A stator designed for use in an electric motor with an external rotor, the stator comprising: a stator body formed from at least one metal sheet, the outer contour of which stator body has a substantially round shape, wherein the stator body has stator teeth circumferentially arranged with stator slots located between them, the stator teeth are connected to one another by a stator flux guide, wherein coil windings run through the stator slots, and wherein: the stator teeth have a trapezoidal shape with a tooth width that increases outwardly; and/or the stator slots have parallel flanks and a coil winding of the coil windings is arranged on each of the stator teeth.

17. The stator of claim 16, wherein the coil windings are formed of separate coils, and wherein the separate coils each comprise a bottom face, a top face, a lateral face, and a coil former with a passage that runs between the bottom face and the top face and that carries a coil winding wound on the lateral face.

18. The stator of claim 17, wherein the bottom faces and the top faces of the coils are formed by an inner coil flange and an outer coil flange.

19. The stator of claim 18, wherein the outer coil flanges are rectangular in shape to form an outer lateral face of the stator.

20. The stator of claim 17, wherein the coil formers consist of plastic.

21. The stator of claim 17, wherein the coil formers are elastically deformable at least in some sections in such a way that their cross sectional areas can be deformed.

22. The stator of claim 17, wherein the separate coils are fitted onto the stator teeth.

23. The stator of claim 16, wherein the stator slots are open to the outside.

24. A rotating electrical machine, comprising: a rotatably mounted rotor having a hollow cylindrical permanent magnet arrangement formed from a plurality of segments; and the stator of claim 16 connected to a component of the rotating electrical machine that is fixed relative to the rotatably mounted rotor; wherein the rotatably mounted rotor is arranged coaxially with the stator so that the rotatably mounted rotor circumferentially surrounds the stator and forms an annular air gap between the rotatably mounted rotor and the stator and so that the rotor can rotate about the stator; wherein the stator has induction coils to form a magnetic field in the air gap; wherein directions of magnetization of the segments of the permanent magnet arrangement differ from segment to segment in such a way that magnetic flux is increased over an inner lateral face of a hollow cylinder facing the stator and thus in the air gap, and is reduced over an opposite, outer lateral face of the hollow cylinder.

25. The rotating electrical machine of claim 24, wherein the rotating electrical machine is an electric motor or a generator of a drive unit of a motorized vehicle for moving people and/or goods, wherein the stator is connected to a component of the drive unit which is fixed relative to the rotatably mounted rotor or is connectable to a component of the vehicle which is fixed relative to the rotatably mounted rotor.

26. The rotating electrical machine of claim 24, wherein the segments of the permanent magnet arrangement have circumferential dimensions differing from one another.

27. The rotating electrical machine of claim 26, wherein segments of the permanent magnet arrangement of which the direction of magnetization is radially oriented have a largest circumferential dimension.

28. The rotating electrical machine of claim 24, wherein the permanent magnet arrangement is enclosed by a concentric retaining ring directly adjacent to the permanent magnet arrangement.

29. A drive unit of a motorized vehicle for moving people and/or goods, the drive unit comprising the rotating electrical machine of claim 24.

30. The drive unit of claim 29, wherein the rotating electrical machine is a generator of the drive unit, and wherein the drive unit further comprises a coupling in series to the generator as a front serial member and an electric motor as a rear serial member.

Description

[0044] The invention will be explained in more detail below, by way of example but without limitation, with reference to drawings of a drive unit. The associated figures show in

[0045] FIG. 1 a segment of the rotor-stator unit of the drive unit according to the invention in plan view, and

[0046] FIG. 2 a coil which can be fitted to a stator tooth, in a sectional view.

[0047] The devices according to the invention are shown merely schematically to the extent necessary to explain the invention. It is not claimed that these are complete or to scale.

[0048] The segment in FIG. 1 shows part of a stator 1, which has trapezoidal stator teeth 3 and rectangular stator slots 5 (shown by dashed lines). A coil 7 is fitted to each stator tooth. The coils 7 are constructed and arranged in such a way that the coil flanges 77, directly adjacent to each other, form the outer lateral face 11 of the stator 1 with the outer radius R.sub.a of the stator 1.

[0049] Concentric to the stator 1, the rotor 13 is arranged in such a way that an air gap 17 (also referred to as a working gap) exists between the outer lateral face 11 of the stator 1 and the inner lateral face 15 of the rotor 13. The width of the air gap 17 is determined by the circumferentially uniform difference between the inner radius R.sub.i of the inner lateral face 15 of the rotor 13 and the outer radius R.sub.a of the outer lateral face 11 of the stator 1.

[0050] The rotor 13 comprises a permanent magnet assembly formed from a plurality of permanent magnets 19. The magnets 19 each have a direction of magnetization represented in FIG. 1 by north pole “N and south pole “S”. The magnets 19 are formed and arranged in such a way, that their direction of magnetization always rotates through 90° from one magnet to the next, adjacent magnet. The circumferential length L.sub.u′ of those magnets 19 which have a radial direction of magnetization is a multiple of the circumferential length L.sub.u″ of the magnets 19 with a direction of magnetization at right angles thereto.

[0051] The magnets 19 are mounted on a ring 21, which serves as a flux ring of the rotor 13 and optionally at the same time for stabilization. The rotor 13 and stator 1 are enclosed in a housing 23, of which only the annular closure is visible.

[0052] FIG. 2 shows a coil 7 which has a coil former 71 with a rectangular cross-section and a central passage 73. A multi-layer, dense coil winding 75 is formed on the coil former 71. The coil winding 75, viewed radially, is delimited on the inside and outside (FIG. 1) in each case by a coil flange 77.

[0053] The coil former 71 consists of an electrically insulating plastic and has flexible portions 79 on two opposite walls (shown by a kink in the wall). To fit the coils 7 onto the stator teeth 3, the distance between these two walls can be increased by applying a compressive force (shown by two arrows) to the other two walls. The pressing causes the flexible portions 79 to deform outwardly (shown by outwardly directed arrows), thus increasing the internal cross-section in that direction so that the coil can be pushed over the outer, larger cross-section of a trapezoidal stator tooth 3. When pressing is complete, the coil former 7 resumes its original form and is thus fixed on the stator tooth 3.