WO2021219164A1

WO2021219164A1 - Stator unit for an electric machine, and corresponding electric machine

Info

Publication number: WO2021219164A1
Application number: PCT/DE2021/100369
Authority: WO
Inventors: Alexandre Fischer; Andreas Ruppert
Original assignee: Schaeffler Technologies AG & Co. KG
Priority date: 2020-04-30
Filing date: 2021-04-22
Publication date: 2021-11-04
Also published as: DE102020111760A1

Abstract

The invention relates to a stator unit (10) for an electric machine, comprising a stator support (14), a stator (12) which is fixed to the stator support (14) and comprises stator teeth (16), concentric windings (18) arranged on the stator teeth (16), at least one connection ring (22) for connecting the windings (18), and a support device (24) which supports the at least one connection ring (22). According to the invention, the stator unit (10) has a positioning assembly (30) which has multiple positioning elements (32) for positioning the support device (24) and/or the connection ring (22) relative to the stator support (14), wherein each positioning element (32) is arranged in a distributed manner over the circumference between the stator support (14) and the support device (24) with respect to an axis which forms the rotational axis of the electric machine. The invention additionally relates to a corresponding electric machine with a rotor and such a stator unit (10).

Description

Stator unit for an electrical machine and corresponding electrical machine

The invention relates to a stator unit for an electrical machine, with a stator support, a stator attached to the stator support with stator teeth, concentrated windings arranged on the stator teeth, at least one connection ring for connecting the windings and a carrier device carrying the at least one connection ring.

The invention also relates to a corresponding electrical machine with a rotor and such a stator unit.

Electrical machines are used in a wide variety of application areas. An example is the use of such electrical machines in motor vehicles in the form of electric hybrid vehicles and in purely electric vehicles. The electrical machines can be designed as drive machines, for example as wheel hub motors. An electrical machine usually has a stator and a rotor that interact magnetically. Different winding techniques are known for forming the coils for the stator. The so-called concentrated winding is used for a particularly dense and compact winding. In this winding technology, individual windings are provided on the individual stator teeth, which enables a very high packing density, the adjacent windings are extremely close to one another. One electrical machine that has been increasingly used recently is the permanent magnet synchronous machine (PSM). Such a permanently excited synchronous machine consists of a stator to be energized and a permanently excited rotor. The stator unit usually consists of a stator with (wire) windings, a stator carrier, a connection ring and a connection terminal for connecting power electronics (LE). Other electrical machines with concentrated stator windings are asynchronous machines (ASM) and separately excited synchronous machines (FSM). Electrical machines with concentrated windings have different numbers of stator teeth. As a rule, three consecutive stator teeth form a pole pair. For electrical machines with a concentrated winding arrangement and star connection for the stator, the individual pole pairs, for example three teeth, must be coupled / connected to one another.

In series-produced permanent magnet synchronous machines (PSM), asynchronous machines (ASM) and separately excited synchronous machines (FSM), the connection rings are often placed, positioned and centered directly on the stators (1 laminated core with distributed winding per x individual teeth with concentrated winding). Three phase-related busbars and, if necessary, a star bar are installed on the carrier device. The connection to the power electronics is established from these three busbars via the connection terminal. In the following these rails are to be referred to as interconnection rings. Notwithstanding this, the rails are sometimes referred to as a connecting ring in their entirety.

The document DE 102018 119831 A1 describes an electrical machine with egg ner stator unit, which has a stator, a stator attached to the stator with stator teeth, arranged on the stator teeth concentrated windings, at least one interconnection ring for interconnecting the windings and at least one interconnection ring carrying the having annular carrier device. A connection terminal for corresponding power electronics is also attached to the carrier device.

It is the object of the invention to specify measures by which a machine-fixed alignment of the at least one interconnection ring, the carrier device and / or components of the electrical machine aligned thereon is ensured in a simple manner.

The object is achieved according to the invention by a stator unit with the features of claim 1 and an electrical machine with the features of claim 10. Preferred embodiments of the invention are set out in the dependent claims. Chen and the following description given, each of which can represent an aspect of the invention individually or in combination.

In the stator unit according to the invention for an electrical machine, which has a stator carrier, a stator with stator teeth attached to the stator carrier, concentrated windings arranged on the stator teeth, at least one connection ring for connection of the windings and a carrier device carrying the at least one connection ring, it is provided that the stator unit furthermore has a positioning arrangement having a plurality of positioning elements for positioning the carrier device and / or the connection ring relative to the stator carrier. The positioning elements are distributed circumferentially with respect to an axis forming the axis of rotation of the electrical machine between the stator carrier and the carrier device. The stator carrier is permanently installed in the housing of the electrical machine, so it is machine-proof. The carrier device, the at least one interconnection ring and / or further components of the electrical machine that are aligned with it are then simply aligned in a machine-fixed manner via the positioning arrangement. If necessary, these components are also fastened to the stator carrier via the positioning elements.

This measure results in a simplified and more precise interconnection ring structure and, if necessary, an improved positioning of a connection terminal to power electronics.

In the following, advantageous configurations of the positioning elements and their interaction with the contours of the stator carrier are given.

According to a preferred embodiment of the invention it is provided that the positioning elements (i) are arranged on the carrier device and have alignment structures for interaction with a respective contour of the stator carrier or (ii) are arranged on the stator carrier and alignment structures for interaction with a respective contour have the carrier device.

It is preferably provided that the positioning arrangement is designed in such a way that the interaction of alignment structures and contours results in an axial alignment. th and / or radial alignment and / or circumferential alignment with respect to the axis caused.

In connection with the design of the positioning elements, it is furthermore preferably provided that the contours or the alignment structures include step structures. The step structures bring about the axial and radial alignment in particular.

In connection with the design of the positioning elements, it is furthermore preferably provided that at least one of the contours and the alignment structure that interacts with it form a projection-recess engagement system. In other words, (a) a recess is provided in the contour and a recess engaging projection is provided in the alignment structure or (b) a recess is provided in the alignment structure and a recess engaging projection is provided in the contour.

In particular, it is provided that the projection-recess engagement system is designed in such a way that it effects the circumferential alignment.

According to a further preferred embodiment of the invention, the stator unit has a connection terminal with a number of connection elements corresponding to the number of connection rings.

It is advantageously provided that the position of power electronics that can be connected to the connection terminal is determined directly or indirectly via the connection terminal.

In the case of the electrical machine according to the invention with a rotor and a stator unit comprising a stator, it is provided that this stator unit is designed as a stator unit mentioned above. Furthermore, the electrical machine generally has a housing and the aforementioned power electronics.

In the following, the invention is explained by way of example with reference to the accompanying drawings using preferred exemplary embodiments, the following The features shown can represent an aspect of the invention both individually and in combination. Show it:

1: Components of a stator unit for an electrical machine according to a preferred embodiment of the invention,

Fig. 2: Details of a stator carrier, a stator and a corresponding circuit arrangement of the stator unit in a sectional view,

Fig. 3: Corresponding details in the area of a positioning element for positioning the interconnection arrangement relative to the stator support in a sectional representation,

FIG. 4: the details of FIG. 3 from a different perspective and FIG

5: Details of another positioning element and its surroundings within the stator unit.

FIG. 1 shows components of a stator unit 10 for an electrical machine, namely the components of a stator 12 of the electrical machine and components that are directly related to this stator 12. The stator 12 has egg NEN annular stator carrier 14 and a plurality of circumferentially arranged around an axis forming the axis of rotation of the electrical machine axis 16, which are surrounded by corresponding windings 18 and are therefore not directly visible. The windings 18 are concentrated windings, so that a concentrated winding structure results. One of the stator teeth 16 is shown as an example in the sectional view of FIG.

Furthermore, FIG. 1 shows an interconnection arrangement 20 for the electrical interconnection of the stator windings 18 of the stator 12 arranged on the stator teeth 16 Support device 24 are held. Each of the interconnection rings 22 is a type of ring-shaped busbar. The interconnection arrangement 20 has Furthermore, a connection terminal 26 with connection elements 28, of which only two of three connection elements 28 are shown here in FIG. These connection elements 26 are often also referred to as HV contacts. The position of power electronics that can be connected / connected to the connection terminal 26 is determined via the connection terminal.

The interconnection arrangement 20 furthermore has a positioning arrangement 30 with positioning elements 32 for positioning the carrier device 24 and / or the interconnection rings 22 relative to the stator carrier 14. In the example shown, the positioning elements 32 are arranged on the carrier device 24 and, in this specific case, are part of the carrier device 24. One of these positioning elements 32 is shown in FIG. Details of the positioning arrangement 30 and its positioning elements 32 are discussed in connection with FIGS. 3 to 5. The finger-shaped connection element 26 is connected to the carrier device 24 via a threaded bushing 34 and makes contact via its free end 36 with contacts 38 of the corresponding connection ring 22.

FIG. 2 shows details of the stator 12, the stator carrier 14 and the corresponding interconnection arrangement 20 of the stator unit 10 in a sectional view through one of the stator teeth 16. The corresponding Wicklun gene 18 contact the interconnection rings 22 with their winding ends forming a respective phase input. On the other side of the carrier device 24, one of the connection elements 28 is arranged.

3 shows corresponding details in the area of one of the positioning elements 32 for positioning the interconnection arrangement 20 relative to the stator carrier 14 in a sectional illustration. The positioning element 32 is arranged on a base body of the carrier device 24 and has an alignment structure 40 for interacting with the contour 42 of an edge of the stator carrier 14. The carrier device 24 and the positioning elements 32 are made from one piece or, in other words, the carrier device 24 has the positioning elements 32. The alignment structure 40 is designed as a step structure 44 and is supported radially and axially on the contour 42 of the stator carrier 14 in relation to the axis A. FIG. 4 shows the details of FIG. 3 from a different perspective. It can be seen how the windings 18 electrically contact the interconnection rings 22 with phase inputs bil Denden winding ends 46. The alignment structure 40 of the positioning element 32 of the carrier device 24 with its step structure 44 overlaps the (edge) contour 42 formed by the end face 46 and inner radius 48 of the stator carrier 14 and axially on the contour 42 of the stator carrier 14.

FIG. 5 shows details of another positioning element 32 and its surroundings within the stator unit 10. This positioning element 32 is more like a cam.

The alignment structure 40 of the positioning element 32 and the corresponding contour 42 of the stator carrier are configured somewhat differently. The contour 42 is shaped by a recess 50 in the stator carrier 14 and the alignment structure 40 by a projection 52 engaging in this recess 50. Together, the recess 50 and the projection 52 engaging in the recess 50 form a projection-recess engagement system 54. This projection-recess engagement system 54 is now designed so that it allows circumferential alignment of the carrier device 24 relative to the stator carrier 14 with respect to the Causes the axis of rotation of the electrical machine forming the axis.

In the following, the most important aspects should be briefly recapitulated:

The carrier device 24 for the interconnection ring 22 is made with a certain number of finger-shaped positioning elements 32 (for short: fingers) on the outer diameter, as shown in FIGS. 1, 3 and 4 or with cam-shaped positioning elements 32 (for short: cams), as shown in FIG 5 shown. The stator carrier 14 is produced with corresponding recesses 50 (notches). Included

(a) the fingers 32 rest axially on the stator carrier 14 so that the degree of freedom along the axis (Z-axis) is blocked (initially called axial alignment),

(b) the fingers 32 are centered on the inner diameter of the stator carrier, so that one degree of freedom in the X and Y directions is blocked (initially called radial alignment) and (c) the projections 52 of the cams 32 are engaged in the notches 50 of the stator carrier 14, so that the degree of freedom of rotation with respect to the axis (Z-axis) is blocked (initially called circumferential alignment).

This direct positioning of the carrier device 24 and the interconnection ring 22 on the stator carrier ensures a very short tolerance chain to the stator carrier, which results in a more precise position of the connection terminal 26 for fixing the housing of the electrical machine. This increased positioning accuracy enables either “stricter accuracy requirements” to be met or, in the case of “softer accuracy requirements”, other manufacturing tolerances can now be opened, which can reduce costs for corresponding parts of the electrical machine.

In addition, this positioning / centering of the connection ring 22 results in a safer, simpler and / or faster assembly process.

List of references stator unit stator stator carrier stator tooth winding interconnection arrangement interconnection ring carrier device connection terminal connection element positioning arrangement positioning elements threaded bushing free end (connection element) contact (interconnection ring) alignment structure contour step structure end face (stator carrier) inner radius (stator carrier) recess projection projection-recess engagement system

Claims

1. Stator unit (10) for an electrical machine, with a stator carrier (14), a stator (12) attached to the stator carrier (14) with stator teeth (16), concentrated windings (18) arranged on the stator teeth (16), at least an interconnection ring (22) for interconnecting the windings (18) and a carrier device (24) carrying the at least one interconnection ring (22), characterized by a positioning arrangement (30) having a plurality of positioning elements (32) for positioning the carrier device (24) and / or of the interconnection ring (22) relative to the stator carrier (14), the positioning elements (32) being arranged circumferentially distributed between the stator carrier (14) and the carrier device (24) with respect to an axis forming the axis of rotation of the electrical machine.

2. Stator unit according to claim 1, characterized in that the positioning elements (32)

- Are arranged on the carrier device (24) and have alignment structures (40) for interacting with a respective contour (42) of the stator carrier (14) or

- Are arranged on the stator carrier (14) and have alignment structures (40) for interaction with a respective contour (42) of the carrier device (24).

3. stator unit according to claim 2, characterized in that the positioning arrangement (30) is designed such that the interaction of alignment test structures (40) and contours (42) axial alignment and / or radial alignment and / or circumferential alignment with respect to the Axis causes.

4. stator unit according to claim 2 or 3, characterized in that the Kon structures (42) or the alignment structures (40) comprise step structures (44).

5. stator unit according to claim 4, characterized in that the step structures (44) effect the axial and radial alignment.

6. stator unit according to one of claims 2 to 5, characterized in that at least one of the contours (42) and the cooperating with it from straightening structure (40) form a projection-recess engagement system (54).

7. stator unit according to claim 6, characterized in that a projection recess engagement system (54) is designed such that it effects the circumferential alignment.

8. stator unit according to one of claims 1 to 7, characterized by a connection terminal (26) with one of the number of interconnection rings (22) corre sponding number of connection elements (28).

9. The stator unit according to claim 8, characterized in that via the connection terminal (26) the position of a power electronics that can be connected to the connection terminal (26) is determined directly or indirectly.

10. Electrical machine, in particular one for a motor vehicle, with a rotor and a stator unit (10) comprising a stator (12) according to one of claims 1 to 9.