EP3114753A1

EP3114753A1 - Stator element for constructing a stator arrangement for an electric machine, stator arrangement and method for constructing a stator arrangement

Info

Publication number: EP3114753A1
Application number: EP15701962.1A
Authority: EP
Inventors: Matthias Steinle; Martin Braun; Jens BURGHAUS; Mickael Kremer; Keir Foster; Johannes Andrusch
Original assignee: Robert Bosch GmbH
Current assignee: Robert Bosch GmbH
Priority date: 2014-03-05
Filing date: 2015-01-28
Publication date: 2017-01-11
Also published as: DE102014203945A1; WO2015132022A1

Abstract

The invention relates to a stator element for constructing a stator arrangement (3) and a stator arrangement (3) for a multi-phase electric machine (1). Said stator element comprises at least one stator tooth (31) which is produced by compressing from a soft magnetic composite material. Said stator element is also designed to be assembled together with at least one other stator element to form a stator arrangement (3).

Description

description

title

Stator element for constructing a Statoranordnunq for an electric machine, Statoranordnunq and method for constructing a Statoranordnunq

Technical area

The present invention relates to electric machines for drive units of motor vehicles, in particular machines with disc rotors. The invention further relates to stator arrangements for such electrical machines and to methods for producing stator arrangements.

State of the art

As machines with disc rotors trained electrical machines are characterized by a high power density at a comparatively low

Weight off. For example, from document WO 2009/1 15247 A1 a

Transverse flux machine with a disc rotor known. In a rotor disk of the disk rotor permanent magnets are embedded at a constant distance from a rotation axis, which are magnetized in the circumferential direction. Adjacent permanent magnets are magnetized opposite to each other, so that the mutually facing poles of two adjacent permanent magnets are each similar. The field lines between these similar poles are thus superimposed so that a rotor magnetic field propagating in the axial and radial directions from the pole gap is generated.

The disk rotor is arranged axially between two stator arrangements, each having a stator winding extending around a motor axis. To each of the stator windings offset radially inwardly and outwardly, each of the stator arrangements in the circumferential direction and projecting in the direction of the disc rotor inner and outer stator teeth.

When current is applied to the stator winding of a stator arrangement, a force acts on the magnetic poles of the disk rotor in the direction of the magnetic pole of the opposite magnetization of the stator magnet, by which a torque dependent on the rotor position as well as magnitude and sign of the stator current can be generated.

A particularly cost-effective variant for the production of base bodies for machine components consists in a pressing and subsequent heat treatment of a soft magnetic powdery composite material (WMV, Soft Magnetic Composite, SMC). However, the basic body for

Stator assemblies for disc rotor machines are typically too large and overly complex to produce with satisfactory economy and quality in terms of sufficient magnetic and mechanical properties by pressing and heat treating a WMV material.

It is therefore an object of the present invention to provide a stator assembly for a machine with disc rotors available that can be produced as reliably and with little effort.

Disclosure of the invention

The above object is achieved by a stator for constructing a

Stator assembly for a multi-phase electric machine according to claim 1 and by a stator assembly for a multi-phase electric machine and a method for producing a stator assembly according to the independent claims.

Further embodiments are specified in the dependent claims. According to a first aspect, a stator element for constructing a stator assembly for a multi-phase electric machine, in particular for a A disc rotor machine, the stator element comprising at least one stator tooth made by compression of a soft magnetic composite, the stator element being further adapted to be assembled with at least one further stator element to the stator assembly.

According to a further aspect, a stator arrangement is provided for a multiphase electric machine, in particular for a machine with a disk rotor, wherein the stator arrangement comprises a plurality of stator elements designed as stator segments, wherein a plurality of the stator elements are joined at their tangential ends by gluing, welding, soldering, Crimping or by mechanical connections with rivets, pins or screws are connected together to form an annular stator assembly having projecting stator teeth in the axial direction.

According to a further aspect, a stator arrangement is provided for a multi-phase electric machine, in particular for a machine with a disk rotor, wherein the stator arrangement has a plurality of stator elements formed as stator segments, wherein abutting tangential ends of adjacent stator segments are provided with corresponding steps, so that their overlapping areas interlock to form an annular stator assembly having axially projecting stator teeth. According to a further aspect, a stator arrangement is provided for a multi-phase electric machine, in particular for a machine with a disk rotor, wherein the stator arrangement has a plurality of stator elements formed as stator segments, wherein abutting tangential ends of adjacent stator segments are provided with corresponding steps, so that their overlapping areas for engaging the stator segments engage one another, wherein the at least one recess of the overlapping region of one of the plurality of stator segments wholly or partially receives the cross section of the base of at least one of the stator teeth of another of the plurality of stator segments. According to a further aspect, a stator arrangement is provided for a multi-phase electric machine, in particular for a machine with a disk rotor, wherein the stator arrangement comprises a plurality of stator elements formed as stator tooth elements, in particular the stator elements formed as stator tooth elements, wherein a main body consists of a soft magnetic Material is provided on, at or in which the

Statorzahnelemente by force and / or form and / or material connection are arranged. One idea of the above stator arrangements is to build them from individual stator elements. The stator elements may be inserted into or interconnected with a body to provide an annular stator assembly having axially projecting stator teeth. The connection of the stator elements with each other or with the base body can be achieved by a suitable fastening. In particular, when manufacturing the stator elements from a WMV material, these can be produced in a simple manner. In addition, the effort in the manufacture of a stator assembly of WMV material can be reduced because the stator segments represent significantly smaller components than the entire stator.

Furthermore, the stator element may be formed as a stator segment, which has a ring-segment-shaped return area and one or more stator teeth projecting on one side of the return area. According to one embodiment, the stator segment may have a step with an overlap region at at least one tangential end in order to overlap a region of the side provided with the stator teeth or the side opposite thereto when assembled with the at least one further stator element formed as a stator segment.

It can be provided that the stator segment has a step with an overlap region at at least one tangential end in order to overlap a region of the side provided with the stator teeth when assembled with the further stator segment, the overlap region having at least one recess with a contour a cross section the base of a stator tooth of another stator segment in whole or in part.

Furthermore, the stator segment can have corresponding steps with respective overlapping areas at both tangential ends, so that when combined with a similar further stator segment, the steps intermesh with each other.

According to one embodiment, the overlapping region may be provided with at least one tab which projects radially inwards and / or outwards from the overlapping region.

Furthermore, the stator element may be formed as a stator tooth element which is provided with a fastening device at its base, which corresponds to an end region associated with the return region, in order to be arranged on or in a soft-magnetic base plate designed as a return region.

In particular, the fastening device of the stator tooth element can connect to the base of the stator tooth to be formed and taper at its base and / or have a stop edge.

Furthermore, the stator tooth elements can be attached to the base plate by gluing, welding, soldering and / or pressing.

It can be provided that the fastening devices of the

Connect stator tooth elements to the base of the respective stator tooth. The attachment means may be tapered and / or have a stop edge, wherein the attachment means are received in the body or pass therethrough.

According to a further aspect, a method for producing the above stator arrangement is provided, wherein a plurality of stator elements formed as stator segments at their tangential ends by gluing, welding, soldering, Pressing or using mechanical connections with rivets, pins or screws interconnected.

According to a further aspect, a method for producing the above stator arrangement is provided, wherein a plurality of stator elements designed as stator tooth elements are arranged on, on or in a basic body of a soft magnetic material by force, form and / or material connection.

Brief description of the drawings

Embodiments are explained below with reference to the accompanying drawings. Show it:

Figures 1 a to 1 c representations of different views of a multi-phase electric machine with a disc rotor;

Figure 2 is a perspective view of an annular stator assembly having protruding in the axial direction stator teeth;

FIGS. 3a to 3c show different views of a stator element designed as a stator segment;

Figure 4 shows a way of connecting stator segments by nesting;

Figures 5a and 5b a way of fixing stator segments

by forming tabs;

FIG. 6 shows a section of a stator arrangement which passes through

Inserting stator tooth elements into a base body is made; and FIGS. 7a to 7c show various possibilities for fastening

Stator tooth elements on a stator yoke ring.

Description of embodiments

Figures 1 a, 1 b and 1 c show cross-sectional views of a three-phase electric machine 1, which is formed in this embodiment as an electric machine with a disc rotor 2. The electric machine 1 may correspond to a pancake machine such as a transverse flux machine. 1 a shows a radial plan view of a cross section in the circumferential direction, FIG. 1 b shows a cross-sectional view in the tangential direction, and FIG. 1 c shows a perspective view of a section of one of the stator arrangements 3.

The electric machine comprises two stator assemblies 3 between which the disk rotor 2 is rotatably disposed about an axis of rotation extending along an axial direction A. The disc rotor 2 is formed of a magnetically and electrically non-conductive material, such as a carbon fiber composite material or the like, and includes an annular magnetically active device, e.g. in the form of embedded, annularly arranged, individual permanent magnets 4, annularly arranged, individual soft magnetic elements or a circumferential electrically conductive ring.

In the embodiment shown, the permanent magnets 4 are provided along an annular magnetic ring arrangement in the disc rotor 2, the permanent magnets 4 in the magnetic ring arrangement being spaced apart in a circumferential direction U.

The polarization of the permanent magnets 4 is aligned in the magnetic ring assembly in the circumferential direction U, wherein the polarizations of each two circumferentially adjacent U permanent magnets 4 are opposite to each other, so that each poles of the same magnetic poles face each other. The mutually in the circumferential direction U facing magnetic poles of the permanent magnets 4 form rotor poles with a resulting magnetic field, which is extends from the area between each two magnetic poles of the permanent magnets 4 in the radial direction R and axial direction A from the disc rotor 2.

It can also be provided two or more than two magnetic ring arrangements, wherein the magnetic ring arrangements can be preferably concentric. In this case, the radial width of each magnetic ring assembly is substantially identical, and preferably the number of permanent magnets 4 in each of the magnetic ring assemblies is also the same.

The stator assemblies 3 are arranged opposite one another, the disk rotor 2 being freely rotatably arranged between the stator arrangements 3 in such a way that the rotor poles formed by the permanent magnets 4 of the magnet ring arrangement extend between stator teeth 31 of the stator arrangements 3.

The stator teeth 31 are arranged annularly in each of the stator assemblies 3 along a Statorzahnanordnung 36, so that the Statorzahnanordnungen 36 of both stator 3 are opposite to each other. The

Statorzahnanordnungen 36 of both stator 3 preferably have the same radial width and face each other in the axial direction A.

The stator teeth 31 together with a magnetic return region 35 form a stator body of magnetically conductive material. The stator teeth 31 are each in the axial direction A, d. H. in the direction of the axis of rotation of the disc rotor 2, protruding from the stator body, d. H. as projections, formed.

The stator teeth 31 extend in the radial direction R as far as possible over the entire radial width of the permanent magnets 4 in the disk rotor 2, wherein the stator teeth 31 are spaced apart in the circumferential direction U by gaps 32 to therein winding strands of the stator windings 34 each having one or more winding wires (depending after number of turns). Each stator assembly 3 has a number of separate ones

Stator windings 34, which corresponds to the number of phases of the machine 1. The respective one stator associated windings 34 are arranged relative to the opposing stator 3 each offset in the circumferential direction U to each other. In this way, the field lines in the air gap, which result from the superimposition of the magnetic fields generated by the permanent magnets 4 in the disk rotor 2 and the stator windings 34 in the stator assemblies 3 and which cause the formation of the engine torque, substantially obliquely to the axial direction A and in the circumferential direction U inclined to the axial direction A, that is substantially transversely to the magnetization direction of the permanent magnets 4th

As can be seen in particular in FIG. 1 c, the stator teeth 31 in the embodiment shown have an elongate cross-section (with respect to the axial direction A) in the radial direction R, which can taper inwardly in the radial direction R. Radial inner and outer ends 37, 38 of the

Stator teeth 31 may be rounded, so that the corresponding winding strand of the corresponding stator winding 34 can be applied when applied to the course of the rounding.

The spaces 32 between the stator teeth 31 serve to the

To magnetically separate stator teeth from each other and to receive the stator windings 34. The winding strands of the stator windings 34 of the individual phases are looped around the stator teeth 31. The height of the stator teeth 31 in the axial direction A is selected such that the winding strand of the corresponding stator winding 34 can be inserted at least for each phase. As illustrated in FIG. 1 c using the example of the three-phase electrical machine 1, the height of the stator teeth 31 in the axial direction A is sufficient to arrange three layers of stator windings 34 one above the other.

For the operation of the stator assembly 3, it is necessary to form them from a soft magnetic material. However, the size of the

Stator assemblies 3 for machines with disc rotors usually too large to be able to produce such a stator assembly with sufficient yield and sufficient tolerance accuracy in one piece. It is therefore provided to construct the stator arrangement 3 from a plurality of individual stator elements. To construct a stator arrangement 3 of the embodiment of FIGS. 1a to 1c, which is shown separately in FIG. 2 in a perspective view, the stator segment 40 shown in different views in FIGS. 3a to 3c can be used, for example. FIG. 2 shows the

Stator assembly 3 with an annular yoke portion 35 as a base body and thereon in the axial direction A projecting stator teeth 31st

The stator element of FIGS. 3a to 3c corresponds to a stator segment 40, which is shaped corresponding to a ring segment. In this way, the stator assembly 3 can be formed from a plurality of such stator segments 40.

In order to ensure stable attachment of the individual stator segments 40 at their tangential ends (at their ends pointing in the circumferential direction U), they can be connected to one another by suitable connection methods. Thus, the stator segments 40 can be connected to each other by gluing, welding, soldering, pressing or by mechanical connections with rivets, pins or screws.

In particular, to increase the connection area between two stator segments 40, at least at one tangential end of the stator segments 40, there is provided a step 41 which, when placed against a corresponding tangential end of another stator segment 40, provides the step with the

Statorzähnen 31 provided side or the opposite side of the yoke portion 35 overlaps accordingly. In the overlapping region 42, a connection in the manner described above, in particular by gluing, welding, soldering, pressing or by mechanical connections with rivets, pins or screws, can be achieved.

If the steps 41 are provided at both tangential ends of the stator segment 40, then they should be designed to be complementary, so that they engage in the assembly of the stator segments 40 to form the annular stator assembly 3 and form the largest possible connection surface.

In order to obtain the largest possible overlap by the step 41, an overlap region 42, which overlap or cover a corresponding region of the provided with stator teeth 31 side of the yoke region 35 may be provided with a recess 43, the cutout or its shape corresponds to a part of the cross section or the entire cross section of a stator tooth 31. By juxtaposing two stator segments 40 then adds the relevant tangential end of the

Stator segment 40 next stator tooth 31 with the contour of its base in the recess 43, so that the overlap region 42 overlaps the corresponding region of the provided with stator teeth 31 side of the return region 35.

Concerns the recess 43, the entire cross-section of a stator tooth 31 at its base (and thus represents a passage opening in the overlap region 42), the joining of stator segments 40 can no longer be achieved by moving against each other in the tangential direction. Rather, a stator tooth 31 is inserted at a tangential end of a stator segment 40 through the corresponding recess 43 of the overlap region 42 by an axial movement relative to each other, so that a load on tangential train connection can be created, as for example in the sectional view of FIG is shown. It is, of course, also possible to provide the overlap region 42 in a tangential length in which a plurality of recesses 43 (two recesses 43 in the example of FIG. 4) are provided for receiving stator teeth 31 of a further stator segment 40.

As shown in FIGS. 5 a and 5 b, at least one tangential end of the stator segment 40 may be provided with at least one tab 44 projecting inward in the radial direction R and / or outwardly from the inference region 35. Preferably, the at least one tab 44 is formed integrally with the return region 35. When two stator segments 40 are put together, the tabs 44 can then be crimped, as shown in FIG. 5b, so that the two stator segments 40 are connected to one another by force and / or positive engagement.

The return region of the stator segments 40 can preferably be provided as a ring segment with a segment angle which is suitable for an integral number of identical stator segments 40 to the Stator assembly 3 to connect with each other. For example, the inference regions 35 can be provided with segment angles of between 10 and 90 °, in particular between 45 ° and 60 °, whereby the overlap region 42 is disregarded in the determination of the segment angle. Of course, the stator segments 40 may also be provided with different segment angles, which are selected and assembled so that a complete ring of the stator assembly 3 is formed.

Preferably, the segment angle of the stator segments 40 should be selected so that the stator segments 40 are sized to be integrally formed, for example, by pressing a soft magnetic composite material and then sintering.

In Fig. 6 is a detail of a stator assembly 3, which corresponds to a stator assembly of Figures 1 a to 1 c, shown in a further construction. The

Structure of Figure 6 includes a separately formed annular yoke region 35, which is in the form of a soft magnetic base plate 51 (base body) is formed. The base plate 51 can be made of iron, steel or an electrical sheet or laminated core (stacked in the axial or radial direction A). The electric sheet can be easier to punch through a process

Be made way.

The stator elements 40 for constructing the stator assembly 3 are formed in this case only as a single stator tooth elements 52, which are arranged in a suitable manner in or on the base plate 51. Basically, the as

Statorzahnelemente 52 formed stator 40 by adhesion and / or positive connection and / or material connection to be arranged on or in the base plate 51. The stator teeth 52 may be molded from a powdered soft magnetic composite (WMV) material and made by compression and subsequent sintering. Due to the small volume and simple geometry of similar produced in this way

Stator tooth elements 52 are high densities and thus very good magnetic properties and strengths possible. In addition, such a production process for stator tooth elements 52 is favorable. Furthermore, the stability of such a produced stator assembly 3 can be improved because the base plate 51 can be made of a different dimensionally stable and robust material and not necessarily made of a compressed soft magnetic composite material must be prepared.

For example, as shown in FIG

Stator tooth member 52 is inserted into a corresponding recess 53 of the base plate 51 and held there by adhesion. That's it

Stator tooth member 52 formed on an inserted into the recess 53 of the base plate 51 end, which serves as a fastening device and adjoins the base of the stator tooth 31, is formed tapered. The attachment of the Statorzahnelements 52 in the base plate 51 is achieved by corresponding pressure of the Statorzahnelements 52 in the base plate 51.

In Figure 7b, a positive connection is shown, wherein a further embodiment of a Statorzahnelements 52 is inserted through a through hole 54 in the base plate 51 and held by a suitable stop edge 55 and an undercut on the stator teeth 31 side facing away from the base 51 at this. The stop edge 55 or the thus formed

Undercuts serve as fastening means of the stator tooth element 52.

FIG. 7c shows how one embodiment of a stator tooth element 52 is fastened on a surface of the base plate 51 by means of material connection. For example, the Storzahnelement 52 can be held by welding or gluing.

Claims

Stator element (40, 52) for constructing a stator arrangement (3) for a polyphase electrical machine (1), wherein the stator element (40, 52) comprises at least one stator tooth (31) produced by compression from a soft magnetic composite material, wherein the Stator element (40, 52) is further adapted to at least one other

Stator element (40, 52) to be assembled to the stator assembly (3).

Stator element (40) according to claim 1, wherein the stator element is designed as a stator segment (40) which has a ring-segment-shaped return region (35) and one or more stator teeth (31) projecting on a side of the return region (35) facing in the axial direction (A) ) having.

Stator element (40) according to claim 2, wherein the stator segment (40) has a step (41) with an overlap region (42) at at least one tangential end to form a region of the stator element when assembled with the at least one further stator element formed as a stator segment (40) overlap with the stator teeth (31) provided side or the opposite side.

The stator element (40) according to claim 2, wherein the stator segment (40) has a step (41) with an overlapping area (42) at at least one tangential end in order to assemble with the other

Stator segment (40) to overlap a portion of the provided with the stator teeth (31) side, wherein the overlap region (42) has at least one recess (43) with a contour to a cross section of the base of a stator tooth (31) of a further stator segment (40 ) in whole or in part. Stator element (40) according to claim 3 or 4, wherein the stator segment (40) at both tangential ends corresponding Stuf ments (41) with respective overlap regions (42), so that when assembled with a similar further stator segment (40) the gradations (41 ) mesh.

A stator element (40) according to any one of claims 2 to 5, wherein the overlap region (42) is provided with at least one tab (44) projecting inwardly and / or outwardly from the overlap region (42) in the radial direction (R).

The stator element (52) according to claim 1, wherein the stator element (52) is formed as a stator tooth element (52) provided with a fixing device at its base, which corresponds to an end portion (35), on or in one to be arranged as a return region (35) formed soft magnetic base plate (51).

Stator element (52) according to claim 7, wherein the attachment means of the stator tooth element (52) adjoins the base of the stator tooth (31) and tapers at its base and / or has a stop edge (55).

Stator assembly (3) for a multi-phase electric machine (1), wherein the stator assembly (3) more than one stator segments (40) formed

Stator elements according to one of claims 2 to 6, wherein a plurality of the stator elements are connected at their tangential ends by gluing, welding, soldering, pressing or by mechanical connections with rivets, pins or screws with each other to an annular

Stator assembly (3) with in the axial direction (A) projecting stator teeth (31) to form.

Stator elements according to claim 3 or 4, wherein adjoining tangential ends of adjacent stator segments (40) are provided with corresponding steps (41), so that their overlapping areas (42) for connecting the stator segments (40) mesh with one another to form a ring. shaped stator assembly (3) with in the axial direction (R) projecting stator teeth (31) to form.

Stator elements according to claim 4 or 5, wherein adjoining tangential ends of adjacent stator segments (40) are provided with corresponding steps (41), so that their overlapping areas (42) interlock, wherein the at least one recess (43) of the overlapping area (42). one of the plurality of stator segments (40) wholly or partially receives the cross section of the base of at least one of the stator teeth (31) of a further one of the plurality of stator segments (40).

Stator arrangement (3) for a multiphase electric machine (1), wherein the stator arrangement (3) comprises a plurality of stator elements (52) formed as Statorzahnelemente (52), in particular stator elements (52) according to claim 7, summarized, wherein a main body of a soft magnetic Material is provided on, on or in which the stator tooth elements (52) are arranged by force, form and / or material connection.

Stator assembly (3) according to claim 12, wherein the stator tooth elements (52) are attached to the base plate (51) by gluing, welding, soldering and / or pressing.

Stator assembly (3) according to claim 12, wherein the fastening means of the stator tooth elements (52) adjoin the base of the respective stator tooth (31) and are tapered and / or have a stop edge (55), wherein the fastening means are received in the base body or go through it.

A method of manufacturing a stator assembly (3) according to any one of claims 9 to 11, wherein a plurality of stator segments (40) are formed

Stator elements (40) according to one of claims 2 to 6 are connected to each other at their tangential ends by gluing, welding, pressing or by mechanical connections with rivets, pins or screws. Method for producing a stator arrangement (3) according to one of claims 12 to 14, wherein a plurality of stator elements (52) formed as stator tooth elements (52) according to claim 7 on, on or in a base body of a soft magnetic material by force, shape and / or or fabric bond can be arranged.