WO2013037553A2 - Stator for an electrical machine - Google Patents

Abstract

A stator for an electrical machine has a plurality of stator segments which form a stator ring and have support teeth for holding coils to which power can be supplied and also radially outer yoke segments which form the outer face of the stator ring. Each stator segment has three support teeth for holding in each case one coil, wherein all the coils of a stator segment are wound from a common, continuous coil wire.

Description

 Description title

 Stator for an electric machine

The invention relates to a stator for an electric machine, in particular for a permanent-magnet synchronous motor, according to the preamble of claim 1.

State of the art

In DE 10 2004 043 424 A1 an internal rotor motor is described, the stator of which has a stator ring and a plurality of circumferentially uniformly distributed, radially inwardly extending carrier teeth for receiving energizable coils. The stator ring consists of individual toothed segments, each having a radial carrier tooth on a yoke or yoke segment, wherein in the mounted state, the yoke segments placed against one another form the continuous stator ring. To connect the toothed segments, nub-shaped elevations or corresponding recesses are arranged on the peripheral end faces of the yoke segments, which engage in a form-fitting manner in the mounted state.

The invention has for its object to provide a stator for an electric motor with simple design measures, which can be easily assembled and is characterized by high efficiency.

This object is achieved with the features of claim 1. The dependent claims indicate expedient developments.

The stator according to the invention is used in electric machines, in particular in permanent-magnet synchronous motors, which can be used for example as servo motors in motor vehicles, for example as a servomotor for seat adjustment or as servomotor for steering assistance. An application is also independent of motor vehicles, for example in hand tools or in electric bicycles (pedelecs).

The stator for the electric machine has a plurality of stator segments, which in the assembled state form a continuous stator ring. Each stator segment has at least three carrier teeth for receiving in each case an energizable coil and a yoke segment, which is part of the stator ring and at the same time carrier of the carrier teeth. At least three radially extending carrier teeth are arranged on each cup-shaped yoke segment. The partially annular yoke segment forms the radially outer, circumferentially extending portion of the stator, from which the support teeth extend radially inwardly, wherein the at least three support teeth are arranged one behind the other in the circumferential direction. The yoke segment and the support teeth are preferably formed in one piece, wherein optionally also a separate embodiment is contemplated, in which the yoke segment and the support teeth are interconnected.

The arrangement of at least three carrier teeth, each with one coil per stator segment, is particularly suitable for so-called 3/2 topologies in which the ratio of number of teeth to number of poles is 3: 2.

Each carrier tooth is a carrier of an energizable coil, which is wound from a coil wire. In the stator according to the invention all coils are wound on the carrier teeth of a common stator segment of a common, continuous coil wire.

This embodiment has several advantages. On the one hand, the assembly of the stator is simplified because at least three carrier teeth and an associated yoke segment form a coherent structural unit, so that the number of components to be mounted for the stator is reduced compared to segments with only one carrier tooth. In addition, the stability of the stator is increased because the stator segments extend over a larger angle portion than in the case of only one carrier tooth. Since all the coils of a stator segment consist of a common, continuous coil wire, there is only one wire start and one wire end per stator segment. This configuration is preferably used as a delta connection, in each case a phase connection is formed between two coils and the two coil wire ends are brought together to form a further, third phase connection. Each stator segment thus forms a threefold group, wherein the stator segments which are combined to form a complete circle can be connected in parallel with the respectively present delta-connected circuits by connecting identical phase connections to the different stator segments in parallel.

Another advantage of the embodiment according to the invention, in particular the delta connection, lies in the possibility of obtaining a higher number of turns per coil with a thinner coil wire and thus a better filling factor as well as an improved possibility of adaptation of the characteristic curve. The higher fill factor also increases the electric power of the electric machine equipped with such a stator.

In the case of a delta connection of the three coils per stator segment with correspondingly three phase connections, the phase connections arranged between two coils advantageously project radially over and are formed as a wire loop. The wire loop extends in particular beyond the radial outer side of the stator segment or beyond the outer side of the yoke segment. On the other hand, the third phase terminal, which is formed by the two coil wire ends, does not necessarily project radially beyond the outside of the stator segment, but can be configured such that the coil wire ends are bent in the axial direction and are within the radius that is from the outside of the coil Yoke segments is formed. The two adjacent coil wire ends are expediently at least approximately - in the circumferential direction - in the middle of the stator segment, ie at the level of the middle coil, but advantageously in the axial direction above the coil.

The adjoining yoke segments, which form the outer ring, are joined together in a suitable manner. For example, welding along the end faces of adjoining yokes may be considered. segments either by single welds or a continuous weld. In principle, however, it is also possible to fix it by means of an encompassing fastening ring, preferably via two fastening rings, which are placed on the two end faces of the stator ring. Also possible is an axially centrally arranged, circumferential fastening ring, for example a rubber ring. In addition, however, other connection measures are also possible, for example positive connections on the front sides of adjacent yoke segments.

Further advantages and expedient embodiments can be taken from the further claims, the description of the figures and the drawings. Show it:

1 is a perspective view of a stator for a stator of an electrical machine, with a circular yoke segment, on which three radially inwardly extending support teeth are arranged, which are each carrier of an energizable coil, wherein the coils of a common, continuous Coil wire are wound,

2 the stator segment in plan view,

3 shows a stator composed of a plurality of stator segments in a perspective view,

4 shows a further stator segment in a perspective view with a fastening ring arranged centrally on the outside for fixing the stator segments,

5 a view corresponding to FIG. 4 of a stator segment, but with two attachment rings arranged on the front side, FIG.

6 shows the detail VI of FIG. 5 in an enlarged view,

Fig. 7 is a schematic diagram of the phase connections of the arranged in delta connection coils of the stator segments, wherein coil groups of different stator segments are connected in parallel. In the figures, the same components are provided with the same reference numerals.

FIGS. 1 and 2 each show a stator segment 1 for the stator of a permanent magnet synchronous motor. The stator segment 1 is part of the stator, wherein a plurality of stator segments 1 are assembled to the stator.

Each stator segment 1 comprises a part-circular yoke segment 2, which forms the circumferential stator ring in the assembled state, and three carrier teeth 3, 4, 5 extending radially inwardly, which are arranged one behind the other in the circumferential direction on the inside of the yoke segment 2. The yoke segment 2 and the carrier teeth 3, 4, 5 may be integrally formed. But also comes in a two-part design, in which case the support teeth 3, 4, 5 are held on the inside of the yoke segment 2 and connected thereto. In an alternative embodiment, not shown, the stator segment 1 is composed of three individually produced individual segments, wherein the individual segments have exactly one carrier tooth 3, 4, 5.

Each of the three carrier teeth 3, 4, 5 is the carrier of an energizable coil 6, 7 and 8, respectively. All three coils 6, 7, 8 of the stator segment 1 are wound from a common, continuous coil wire 9. The winding takes place in such a way that the coil wire 9 is wound adjacent to a circumferential end face of the stator segment to form an outer coil 6 or 8, then forms the middle coil 7 and finally the opposite, outer coil 8 or 6 The free coil wire ends 9a and 9b are guided from the peripheral edge to the center of the stator segment and bent axially upwards.

In the transition between the outer coils 6 and 8 to the middle coil 7 of the coil wire 9 is formed as a respective wire loop 10 and 1 1, which extends radially beyond the outer surface of the yoke segment 2 outgoing. For this purpose, the coil wire is guided through openings 13 in a wall 14, which are arranged on the inside of the yoke segment 2. Overall, in this way two wire loops 10 and 1 1 between each an outer coil 6 or 8 and the central coil 7 is formed. The two wire loops 10, 1 1 each form a phase connection. Another phase connection 12 is formed by the two merged, adjacent coil wire ends 9a, 9b. In this way, a delta connection of the coils with the phase terminals 10, 11 and 12 is formed, to each of which a phase U, V and W is assigned.

In Fig. 3, a stator 15 is shown with a continuous stator ring, which is composed of individual yoke segments 2. The stator consists of a total of six individual stator segments 1 and thus has eighteen coils, wherein three phase terminals 10, 1 1, 12 for phases U, V, W are arranged per stator segment.

As can also be seen from FIG. 3, adjacent yoke segments 2 are welded together via three axially distributed spot welds 16. In this way, a firm connection of the individual stator segments 1 is achieved.

Further types of connection are shown in FIGS. 4 to 6. 4, a fastening ring 17 is arranged on the outer side of the yoke segment 2, which extends axially centrally on the outside of the yoke segment 2 and encloses all the stator segments 1 in the region of the wall of the yoke segment 2. The fastening ring 17 is formed for example as a rubber ring.

In the embodiment according to FIGS. 5 and 6, a total of two fastening rings 17 are arranged on the outer side of the yoke segment 2, wherein the fastening rings 17 enclose all yoke segments or stator segments. The fastening rings 17 are located on the two axially opposite end faces of the yoke segment 2 and can, as shown in the enlarged detail of FIG. 6, engage over them in the radial direction.

In Fig. 7, the interconnection is shown at the phase terminals on each stator segment 1 in a schematic manner. The phase connections are connected in parallel so that identical phase connections 10, 11, 12 of the various stator segments 1 are connected in parallel and can be assigned to the phases U, V and W.

Claims

claims 1 . Stator for an electric machine, in particular for a permanently excited synchronous motor, with a plurality of stator segments (1) which form a stator ring and carrier teeth (3, 4, 5) for receiving energizable coils (6, 7, 8) and radially outer, the outer side of the stator ring forming yoke segments (2), which are carriers of the radially inwardly directed carrier teeth (3, 4, 5), characterized in that each stator segment (1) has three carrier teeth (3, 4, 5) for receiving one each Coil (6, 7, 8) and that all coils (6, 7, 8) of a stator segment (1) from a common, continuous coil wire (9) are wound. 2. Stator according to claim 1, characterized in that for realizing a delta connection between each two coils (6, 7, 8), a phase connection (10, 1 1, 12) is formed and the two coil wire ends (9a, 9b) to another Phase connection (10, 1 1, 12) are joined together. 3. Stator according to claim 2, characterized in that between two coils (6, 7, 8) lying phase terminals (10, 1 1, 12) are formed as a radially projecting wire loop. 4. Stator according to claim 2 or 3, characterized in that the of the two coil wire ends (9a, 9b) formed phase connection (10, 1 1, 12) is arranged in the circumferential direction at least approximately in the middle of the stator segment (1). 5. Stator according to one of claims 1 to 4, characterized in that the end faces of adjoining yoke segments (2) are welded together. 6. Stator according to one of claims 1 to 5, characterized in that the stator to the stator ring segments (1) via a fastening ring (17) are fixed. 7. Stator according to claim 6, characterized in that the fastening ring (17) is mounted on an end face of the stator ring. 8. Stator according to claim 7, characterized in that on both end sides of the stator ring in each case a fastening ring (17) is placed. 9. Stator according to one of claims 1 to 8, characterized in that the same phase terminals (10, 1 1, 12) are connected in parallel to the different stator segments (1). 10. Stator according to one of claims 1 to 9, characterized in that the stator segment (1) is composed of three separate individual segments, each having exactly one carrier tooth (3, 4, 5). 1 1. Electric motor with a stator (15) according to one of claims 1 to 9.