Stator, rotor, electric machine and method for producing a stator and method for producing a rotor

Abstract

Stator (1) for an electric machine (2), in particular for an electric machine (2) within a drive train (3) of a motor vehicle (4), comprising • a stator body (5) with a plurality of circumferentially distributed stator teeth (6) and stator slots (7) formed between the stator teeth (6) and extending in the axial direction through the stator body (5), wherein • the stator body (5) is formed from a packaged lamination stack (8) with a plurality of electrical laminations (9), • and the stator body (5) is fixed in or on a receiving structure (10), wherein a plurality of the electrical sheets (9) each have fixing means (11) formed integrally therewith, which, under the influence of an axial force (12) acting on the stator body (5) during assembly at room temperature in or on the receiving structure (10), effect a transverse press connection between the plurality of electrical sheets (9) having fixing means (11) and the receiving structure (10), so that the stator body (5) is fixed in or on the receiving structure (10) in its state mounted in or on the latter, wherein the fixing means (11) protrude radially from the stator body (5) and, when inserted into the receiving structure (10), have an oversize relative to the latter. characterized in that the sheet stack (8) comprises a first group (16) of electrical sheets (9), a second group (17) of electrical sheets (9) and a third group (18) of electrical sheets (9), wherein the first group (16) of electrical sheets (9) is positioned in or on the receiving structure (10) with play, the second group (17) of electrical sheets (9) is positioned with play relative to the receiving structure (10) in or on the latter, wherein the play (19) of the second group (17) of electrical sheets (9) relative to the receiving structure (10) is smaller than the play (20) of the first group (16) of electrical sheets (9) relative to the receiving structure (10), the third group (18) of electrical sheets (9) has the fixing means (11), wherein in each case an electrical sheet (9) of the third group (18) of electrical sheets (9) rests on both sides against an electrical sheet (9) of the first group (16) of electrical sheets (9), and in each case an electrical sheet (9) of the second group (17) of electrical sheets (9) rests on both sides against an electrical sheet (9) of the first group (16) of electrical sheets (9).

Description

The present invention relates to a stator for an electric machine, in particular for an electric machine within a drive train of a motor vehicle, comprising a hollow cylindrical stator body having a multiplicity of stator teeth arranged in a circumferentially distributed manner and stator grooves formed between the stator teeth and extending through the stator body in the axial direction, wherein the stator body is formed from a laminated sheet stack having a multiplicity of electric sheets, and the stator body is fixed in or on a receiving structure. The invention further relates to a rotor, an electric machine and a method for producing a stator and to a method for producing a rotor.Electric motors are increasingly used for the drive in motor vehicles in order to create alternatives to internal combustion engines that require fossil fuels. In order to improve the suitability of electric drives for all days and in addition to be able to offer users the usual riding comfort, considerable efforts have already been made.A detailed illustration of an electric drive is given in an article of the journal ATZ 113. Vol. 05 / 2011, pages 360-365 of Erik Schneider, Frank Fickl, Bernd Cebulski and Jens Liebold, with the title: High-Integration and Flexible Electric Drive Unit for E-vehicles. In this article, a drive unit for an axle of a vehicle is described, which drive unit comprises an electric motor which is arranged concentrically with respect to a bevel gear differential, wherein a shiftable 2-gear planetary gear set is arranged in the power train between electric motor and bevel gear differential, which is likewise positioned coaxially with respect to the electric motor or the bevel gear differential or spur gear differential. The drive unit is of very compact construction and, owing to the shiftable 2-gear planetary gear set, allows a good compromise between climbing capability, acceleration and energy consumption. Drive units of this type are also referred to as E-axles or electrically operable drive train.In addition to the purely electrically operated drive trains, hybrid drive trains are also known. Drive trains of this type of a hybrid vehicle usually comprise a combination of an internal combustion engine and an electric motor, and make possible, for example in balling areas, a purely electric operating mode with a simultaneously sufficient range and availability, especially during cross country drives. In addition, it is possible to drive simultaneously by the internal combustion engine and the electric motor in certain operating situations.In the development of electric machines intended for E-axles or hybrid modules, there is a continuing need to increase their power densities. A very important performance criterion for an electric machine in this context is its efficiency. Here, a minimum value for the maximum in the characteristic map, a minimum cycle efficiency or minimum efficiencies for specific operating points are usually required. Furthermore, all waste heat must also be dissipated by a cooling system, as well as thermal requirements being influenced by the amounts of heat (and localizations) generated at specific operating points.The main part of these losses is formed by the copper losses and the iron losses, the composition here depending strongly on the respective operating point.For this reason, many different means are used to minimize the losses. In the case of iron losses, this often results in the selection of a thinner, less-loss electric sheet. A further possibility for reducing the iron losses in a stator is to anneal the individual laminations or the entire laminated core following the punching and stacking, which is however regularly disadvantageous from the standpoint of energy and cost.Stators of this type, which are constructed from electric laminated cores, are usually connected in a rotationally fixed manner to a receiving structure, for example a stator carrier or a housing structure.WO 2018 / 036 952 A1 discloses, for example, a rotor in which the rotor laminations are fastened to the shaft by means of deformable lugs. Other fastening possibilities, such as, for example. Clamping means can be taken from DE 10 2019 116 906 A1.In order to join such a stator having a cylindrical outer contour, for example, into a stator carrier having a cylindrical inner contour, the latter is generally heated to a temperature of 150 to 200° C., then joined and subsequently cooled down again to a temperature on a cooling section, which makes possible the further handling of the stator or of the joined assembly.It is the object of the invention to avoid or at least reduce the problems known from the prior art and to provide a stator which can be fixed particularly favorably and securely to or in a receiving structure in terms of energy. It is furthermore the object of the invention to realize an improved rotor, an optimized method for producing a stator or a rotor, and an improved electric machine.This object is achieved by a stator for an electric machine, in particular for an electric machine within a drive train of a motor vehicle, comprising a hollow cylindrical stator body having a multiplicity of stator teeth arranged in a circumferentially distributed manner and stator grooves formed between the stator teeth and extending through the stator body in the axial direction, wherein the stator body is formed from a laminated stack of sheets having a plurality of electric sheets, and the stator body is fixed in or on a receiving structure, wherein a plurality of the electric sheets each have fixing means formed integrally therewith, which bring about a transverse press connection between the plurality of electric sheets having the fixing means and the receiving structure under the influence of an axial force acting on the stator body during the mounting at room temperature in or on the receiving structure, such that the stator body is fixed in or on the receiving structure in its state mounted in or on the latter.This achieves the advantage that a stator can be provided with a cross-press bond that can be activated mechanically at room temperature, as a result of which thermal joining of the stator to a receiving structure can be dispensed with. By mechanically forming the cross-press fit at room temperature, damage to the stator, e.g. to the insulating materials, caused by thermal joining, which damage can arise by heating the stator to, e.g., 200° C., can likewise be avoided.Moreover, depending on the configuration, a reduction in the sensitivity of the shaft-hub connection with respect to the stator carrier diameter tolerance is possible. The separation of the stator and the receiving structure for the purpose of recycling can also be simplified by the mechanical process.Furthermore, it is provided that the fixing means protrude radially from the rotor body and have an excess dimension with respect to the receiving structure when it is inserted into the receiving structure. The advantageous effect of this embodiment is due to the fact that the stator already forms a transverse press connection when it is inserted into the receiving structure, so that an additional mechanical activation step can possibly be dispensed with.Furthermore, the sheet metal stack has a first group of electric sheets, a second group of electric sheets and a third group of electric sheets, wherein the first group of electric sheets is positioned in or on the receiving structure with play, the second group of electric sheets is positioned in or on the receiving structure with play, wherein the play of the second group of electric sheets relative to the receiving structure is smaller than the play of the first group of electric sheets relative to the receiving structure, the third group of electric sheets has the fixing means, wherein in each case one electric sheet of the third group of electric sheets bears on both sides in each case on one electric sheet of the first group of electric sheets, and in each case one electric sheet of the second group of electric sheets bears on both sides in each case on one electric sheet of the first group of electric sheets. The advantage of this embodiment is that a stator laminated core that can be mounted and activated particularly securely can be realized.First, the individual elements of the claimed subject matter of the invention are explained in the sequence in which they are stated in the set of claims and particularly preferred embodiments of the subject matter of the invention are described below.The stator according to the invention is preferably designed for use in a radial flux machine. A stator for a radial flux machine is usually of cylindrical construction and generally consists of electric sheets which are electrically insulated from one another and are of layered construction and are laminated to form laminated cores. Distributed over the circumference, grooves are let into the electric sheet, running essentially parallel to the rotor shaft, which grooves accommodate the stator winding or parts of the stator winding. The stator grooves preferably have a substantially U-shaped cross-sectional contour. Most preferably, a plurality of the stator slots have straight slot walls extending in the radial direction. In particular, a groove wall opposite a positioning portion in a stator groove is formed straight.One or more stator winding(s) are let into the stator slots of the stator according to the invention. A stator winding comprises an electrically conductive conductor, the longitudinal extent of which is substantially greater than its diameter. The electrical conductor can have basically any desired cross-sectional shape. Rectangular cross-sectional shapes are preferred, since high packing and consequently power densities can be achieved with these. Most preferably, a stator winding is formed from copper. Preferably, a stator winding has an insulation. For insulating the stator winding, mica paper, which for mechanical reasons may be reinforced by a glass fabric carrier, may be wound in strip form around one or more stator windings which are impregnated by means of a curing resin. In principle, it is also possible to use a curable lacquer layer without a mica paper in order to insulate a stator winding.The stator winding can be designed, for example, as a wave winding or a hairpin winding.The stator according to the invention also has a stator body. The stator body can be formed in one part or in multiple parts, in particular in segments. A one-piece stator body is distinguished in that the entire stator body, viewed circumferentially, is formed in one piece. The stator body is generally formed from a multiplicity of stacked laminated electric sheets, each of the electric sheets being formed closed to form a circular ring. A stator body of segmented construction is characterized in that it is constructed from individual stator segment parts. The stator body can be constructed from individual stator teeth or stator tooth groups, wherein each individual stator tooth or each individual stator tooth group can be formed from a multiplicity of stacked laminated electric sheets, wherein each of the electric sheets is formed as a stator segment sheet part.The stator body is preferably formed from one or more stator laminated cores. A stator laminated core is understood to mean a plurality of laminated individual laminations or stator laminations which are generally produced from electric sheet and are laminated and laminated one above the other to form a stack, the so-called stator laminated core. The individual sheets can then remain held together in the laminated core by adhesion, welding or screwing.The stator teeth of the stator are preferably formed in the stator body. Stator teeth are components of the stator body which are formed as circumferentially spaced, toothlike, radially inwardly directed parts of the stator body and between their free ends and a rotor body an air gap for the magnetic field is formed. The air gap is the gap existing between the rotor and the stator. In a radial flux machine, this is a substantially circular ring-shaped gap with a radial width which corresponds to the distance between the rotor body and the stator body.The stator is provided in particular for use in an electric machine within a drive train of a motor vehicle. The electric machine is provided in particular for use within a drive train of a hybrid or fully electrically driven motor vehicle. In particular, the electric machine is dimensioned such that vehicle speeds greater than 50 km / h, preferably greater than 80 km / h and in particular greater than 100 km / h can be achieved. The electric machine particularly preferably has a power greater than 30 kW, preferably greater than 50 kW and in particular greater than 70 kW. It is furthermore preferred that the electric machine provides rotational speeds greater than 5,000 U / min, particularly preferably greater than 10,000 U / min, very particularly preferably greater than 12,500 U / min.Advantageous embodiments of the invention are specified in the dependent claims. The features listed individually in the dependent claims can be combined with one another in a technically expedient manner and can define further embodiments of the invention. In addition, the features specified in the claims are more precisely described and explained in the description, further preferred embodiments of the invention being presented.According to an advantageous embodiment of the invention, it can be provided that the plurality of electrical sheets having fixing means are substantially identically shaped, as a result of which the manufacturing complexity and the manufacturing costs can be kept low.According to a further preferred development of the invention, it can also be provided that the fixing means is designed as a circular shaped deformation which protrudes in the axial direction out of the plane of an electric sheet. It can thereby be achieved that the fixing means can be formed in a particularly simple manner from a manufacturing standpoint.This embodiment furthermore has the advantage that such a stator laminated core can be inserted into a receiving structure with play and the transverse press fit is only activated mechanically when a predefined position is reached, which can simplify the assembly process.According to a further particularly preferred embodiment of the invention, it can be provided that the fixing means are designed as circular ring sections, which can promote good mechanical activation and a sufficiently strong transverse press connection.In a likewise preferred embodiment variant of the invention, it can also be provided that the first group of electric sheets, the second group of electric sheets and the third group of electric sheets consist of substantially identically shaped electric sheets which are arranged in the stack of sheets rotated with respect to one another. This can achieve a complexity reduction of the production processes, which can also have positive effects on the production costs.It can also be advantageous to further develop the invention to the effect that the receiving structure is a housing, a stator carrier or a shaft. The stator can be designed for an electric machine configured as an internal rotor or external rotor.The object of the invention is also achieved by a method for producing a stator of an electric machine, comprising the following steps:• Provision of a receiving structure in or on which a stator body can be fixed,• Provision of a stator body having a multiplicity of stator teeth arranged in a circumferentially distributed manner and stator grooves formed between the stator teeth and extending through the stator body in the axial direction, wherein the stator body is formed from a laminated stack of sheets having a plurality of electric sheets, wherein a plurality of the electric sheets each have fixing means formed integrally therewith, which, under the influence of an axial force acting on the stator body during the mounting in or on the receiving structure, bring about a transverse press connection between the plurality of electric sheets having the fixing means and the receiving structure, such that the stator body can be fixed in or on the receiving structure in its state mounted in or on the receiving structure,• Mounting of the stator body in or on the receiving structure at room temperature.Furthermore, the object of the invention can also be achieved by means of a rotor for an electric machine, in particular for an electric machine within a drive train of a motor vehicle, comprising a rotor body which is formed from a laminated sheet stack having a plurality of electric sheets, and the rotor body is fixed in or on a rotor shaft, wherein a plurality of the electric sheets each have fixing means which are formed integrally with said electric sheets and which, under the influence of an axial force acting on the rotor body during the assembly at room temperature on the rotor shaft, bring about a transverse press connection between the plurality of electric sheets having the fixing means and the rotor shaft, with the result that the rotor body is fixed on the rotor shaft in its state in which it is mounted on said rotor shaft.It goes without saying that all the advantageous embodiments of the stator according to the invention described above can be transferred in an analogous manner to the rotor according to the invention.The object of the invention is furthermore achieved by a method for producing a rotor of an electric machine, comprising the following steps:• Provision of a rotor shaft in or on which a rotor body can be fixed,• Provision of a rotor body which is formed from a laminated stack of laminations having a plurality of electric laminations, wherein a plurality of the electric laminations each have fixing means which are formed integrally therewith and which, under the influence of an axial force acting on the rotor body during the mounting on the rotor shaft, bring about a transverse pressure connection between the plurality of electric laminations having the fixing means and the rotor shaft, with the result that the rotor body can be fixed in or on the rotor shaft in its state in which it is mounted on the rotor shaft,• Mounting of the rotor body on the rotor shaft at room temperature.Finally, the object of the invention can also be achieved by an electric machine, in particular for a drive train of a motor vehicle, comprising a stator according to one of Claims 1-8 and / or a rotor according to Claim 10.The invention will be explained in more detail below with reference to figures without limiting the general concept of the invention.It shows: FIG. 1 shows an electric machine in a cross-sectional view, FIG. 2 shows an electric machine in an axial sectional view, FIG. 3 shows a first embodiment of fixing means in a laminated sheet metal stack of a stator in a first mounting position in an axial sectional illustration, FIG. 4 shows a first embodiment of fixing means in a laminated sheet metal stack of a stator in a second mounting position in an axial sectional illustration, FIG. 5 shows a first embodiment of fixing means in a laminated sheet metal stack of a stator in a third mounting position in an axial sectional illustration, FIG. 6 shows an embodiment of an electric sheet in a cross-sectional view, FIG. 7 shows a second embodiment of fixing means in a laminated sheet metal stack of a stator in a first mounting position in an axial sectional illustration, FIG. 8 shows a second embodiment of fixing means in a laminated sheet metal stack of a stator in a second mounting position in an axial sectional illustration, FIG. 9 shows an embodiment of an electric sheet in a perspective detailed illustration, FIG. 10 shows a motor vehicle having an electrically operable drive train in a schematic block diagram.FIGS. 1-2 show an electric machine 2 for a drive train 3 of a motor vehicle 4, as is also outlined in FIG. 10.The stator 1 comprises a hollow cylindrical stator body 5 with a plurality of stator teeth 6 arranged in a circumferentially distributed manner and stator grooves 7 formed between the stator teeth 6 and extending through the stator body 5 in the axial direction, in which the stator winding 24 is accommodated. The electric machine 2 shown is shown as a radial flux machine in an internal rotor configuration in which the rotor 23 rotates in the hollow cylindrical stator body 5.The stator body 5 is formed from a laminated sheet stack 8 with a plurality of electric sheets 9 and is fixed in a receiving structure 10, which is for example a stator carrier or a housing structure, for example a motor housing.A plurality of the electric sheets 9 each have at least one fixing means 11 formed integrally therewith, which, under the influence of an axial force 12 acting on the stator body 5 during the assembly at room temperature in or on the receiving structure 10, bring about a transverse press connection between the plurality of electric sheets 9 having the fixing means 11 and the receiving structure 10, with the result that the stator body 5 is fixed in or on the receiving structure 10 in its state in which it is mounted in or on the latter.This is explained in more detail with reference to two embodiments.In a first embodiment, which is shown in FIGS. 3-5, the fixing means 11 project radially out of the stator body 5 and, when inserted into the receiving structure 10, have an excess with respect to the latter.The sheet metal stack 8 has a first group 16 of electric sheets 9, a second group 17 of electric sheets 9 and a third group 18 of electric sheets 9, wherein the first group 16 of electric sheets 9 is positioned therein with play with respect to the receiving structure 10. The second group 17 of electric sheets 9 is positioned therein with play relative to the receiving structure 10, wherein the play 19 of the second group 17 of electric sheets 9 relative to the receiving structure 10 is smaller than the play 20 of the first group 16 of electric sheets 9 relative to the receiving structure 10.The third group 18 of electric sheets 9 has the fixing means 11, wherein in each case one electric sheet 9 of the third group 18 of electric sheets 9 bears on both sides in each case against an electric sheet 9 of the first group 16 of electric sheets 9, and in each case one electric sheet 9 of the second group 17 of electric sheets 9 bears on both sides in each case against an electric sheet 9 of the first group 16 of electric sheets 9.The sheet metal stack 8 of the stator body 5 is therefore designed such that the outer contour of the sheet metal stack 8 has three different outer diameters. These can be realized either radially distributed in a single sheet metal cut or by three different sheet metal cuts which differ only in their outer diameter.The third group 18 of the electric sheets 9 has an excess size with respect to the receiving structure 10, for example a stator carrier inner diameter, and thereby forms a fixing means 11.The first group 16 and the second group 17 of electric sheets 9 then form clearance fits with the receiving structure 10 of different strengths.The groups 16, 17, 18 of the electrical sheets 9 are arranged in such a way that the desired sequence of the three different outer diameters is depicted in the axial direction. In the case of a realization in a single sheet metal section, this can be effected by rotating the individual electric sheets 9 with respect to one another. Such an electric sheet is shown in FIG. 6. The fixing means 11 are formed here as circular ring sections 15 on the electric sheet 9. In this case, the first group 16 of electric sheets 9, the second group 17 of electric sheets 9 and the third group 18 of electric sheets 9 then consist of substantially identically shaped electric sheets 9, which are arranged in the stack of sheets 8 rotated with respect to one another.In the case of three different sheet metal cuts, the corresponding sheet metal cuts of the groups 16, 17, 18 of the electric sheets 9 must be stacked in the correct sequence. The three different diameters are selected in such a way that the axial displacement of the sheet metal stacks 8 in the receiving structure 10 in an axial direction 12 can take place at room temperature in such a way that receiving structures 10 do not suffer any mechanical damage as a result. This is achieved in that the smaller diameters allow the oversized diameter or the fixing means 11 to be bent on one side in the axial direction (toward the plate shape).With such a sheet stack 8, the joining of the stator body 5 into the receiving structure 10 can then take place as follows: If necessary, the stator body 5 is initially axially prestressed. As can be easily followed with reference to FIG. 4, the stator body 5 is pressed axially into the receiving structure 10 at room temperature. As a result of this design, the necessary press-in force in relation to the lateral surface is substantially smaller than in the case of a purely cylindrical transverse press fit. The stator body 5 is first pressed in further than the intended end position.The stator body 5 is then moved in the opposite direction with respect to the receiving structure 10, which is shown in FIG. 5. In this case, the individual electric sheets 9 of the third group 18 engage the largest diameter in the stator body 5, are set up and are deformed axially again to a plate shape to such an extent that they axially abut the next electric sheet 9 of the second group 17 having the average diameter. As a result, a later axial displacement without a large, acting axial force is effectively prevented.FIGS. 7-8 show a second embodiment of a sheet metal stack 8 and will be explained below. In this embodiment, the fixing means 11 are designed as a circular shaped deformation 14 which protrudes in the axial direction out of the plane 13 of an electric sheet 9.The sheet metal section of the electric sheets 9 for the sheet metal stack 8 is therefore designed such that, in the initial state, before the mechanical activation of the transverse compression bond, there is a clearance or slight transition fit between the stator body 5 and the receiving structure 10, such that the stator body 5 can be inserted axially into the hollow cylindrical receiving structure 10, e.g. a stator carrier, without great force being required.The circular shaped forming 14 protruding in the axial direction from the plane 13 of an electric sheet 9 is perforated by oval openings 25 which are arranged equidistantly over the circumference of the forming 14. These openings 25 can also function, for example, as cooling channels in the stator body 5. The apertures 25 also allow embossing at various stages in the die for distributing forces along the die length.Connecting webs 27 extending in the radial direction are formed in the circumferential direction through the openings 25, which extend out of the plane 13 of the electrical sheet 9. In the circumferential direction between two adjacent openings 25, a triangular notch 26 extending radially inward from the outer circumference of the electric sheet 8 projects into the electric sheet 9. The notches 26 interrupt the outer diameter in order to prevent a continuous outer yoke part from reducing the normal force usable in the cross-press fit during the activation of the cross-press fit by circumferential tensile stresses (caused by diameter enlargement). The notch 26 can also have a contour that deviates from the triangular shape. Thus, in the case of the cross-section 26, in particular the notch base can also be rounded in order to prevent an excessively high notch effect and thus damage to the metal sheet during the activation of the cross-press fitThe forming 14 can be formed in the electric sheet, for example, during a punching process.During this punching process for forming the forming 14, the radially outer or radially inner part of the sheet metal stack 8 can be held in place with a hold-down device fixed in the plane, so that the outer diameter of the sheet metal stack remains unchanged during the forming. The holding-down device and its counterpart in the die can, however, also be designed to be movable in the radial direction by a certain distance, so that during the forming process this part is drawn somewhat inward. Here, it is to be ensured that in the region tangentially between the connecting webs 27 the radially outer part can deform out of the sheet metal plane. Thus, this part has the possibility of assuming the shape of a wave spring, whereby the outer diameter is reduced without plastic deformation of the electric sheet 9 in this region. The wave-shaped configuration of the parts between the movable holding-down devices allows the wave shape (position of the peaks and valleys) to be predefined.If the connecting webs 27 of the forming 14 are now deformed in the axial direction by an axial force 12, the stator body 5 after this deformation has a radially larger diameter than in the undeformed state of the forming 14, which can be easily understood from the overview of FIGS. 7-8. As a result, a press connection is formed between the stator body 5 and the receiving structure 10, which is shown in FIG. 8.In the axial direction, for the mechanical activation of the transverse press fit, the sheet metal stack 8 is supported on the stop 21. The stop 21 provides stop surfaces in this case, which make the sheet metal stack 8 abut radially inside as well as radially outside the connecting webs 27 or the forming 14. The stop 21 has recesses 22 in the region of the forming 14 which are formed such that the arc length in the radial direction is shorter than the arc length of the connecting webs 27 in the sheet metal stack 8.The sheet metal stack 8 is now first pushed axially into the attachment structure 10 with low force or even without force up to the stop 21. The sheet stack 8 is then pressed onto the stop 21 by means of a holding-down device, not shown, wherein this holding-down device has axially continuous recesses for the pre-embossed connecting webs 27. The cut-outs in the hold-down device subsequently press punches, which press or caulked the pre-embossed connecting webs 27 into the cut-outs 22 provided for them in the stop 21, which is shown in FIG. 8.Because the connecting webs 27 are shorter in the activated state than in the pre-embossed state, they form compressive stresses in themselves. These produce equally large, opposing forces on the two parts of the electrical sheets 9 connected by these webs, in this case therefore on the radially inner and outer regions of the sheet stack 8, which force is transmitted from the regions which directly participate in the transverse press bond to the partner of the transverse press bond and thus ensure that a torque can be transmitted via this bond.In the exemplary embodiments shown, the stator body 5 can thus be mounted in or on the receiving structure 10 by the mechanical activation of the transverse press fit at room temperature.The invention has been explained in the figures essentially for a stator 1. It is understood that the inventive concept can also be transferred from a stator 1 to a rotor 23 of an electric machine 2. In this case, the rotor 23 can then have a rotor body which is formed from a laminated sheet stack 8 having a plurality of electric sheets 9 and the rotor body is fixed in or on a rotor shaft, as is indicated in FIG. 2. In this case, a plurality of the electric sheets 9 then each have fixing means 11 formed integrally therewith, which, under the influence of an axial force 12 acting on the rotor body during the assembly at room temperature on the rotor shaft, bring about a transverse press connection between the plurality of electric sheets 9 having the fixing means 11 and the rotor shaft, with the result that the rotor body is fixed thereon in its state in which it is mounted on the rotor shaft.The invention is not limited to the embodiments shown in the figures. The foregoing description is, therefore, not to be considered as limiting, but illustrative. The following claims should be understood to mean that a said feature is present in at least one embodiment of the invention. This does not exclude the presence of further features. If the patent claims and the above description define "first" and "second" features, this designation serves to distinguish two features of the same type without specifying a ranking.List of reference characters1 Stator 2 Electric machine 3 Drive train 4 Motor vehicle 5 Stator body 6 Stator teeth 7 Stator grooves 8 Sheet metal stack 9 Electric sheets 10 Receiving structure 11 Fixing means 12 Axial force 13 Plane 14 Forming 15 Circular ring sections 16 Group 17 Group 18 Group 19 Clearance 20 Clearance 21 Stop 22 Cutout 23 Rotor 24 Stator winding 25 Openings 26 Notches 27 Connecting webs

Claims

Stator (1) for an electric machine (2), in particular for an electric machine (2) within a drive train (3) of a motor vehicle (4), comprising • a stator body (5) having a multiplicity of stator teeth (6) arranged in a circumferentially distributed manner and stator grooves (7) formed between the stator teeth (6) and extending through the stator body (5) in the axial direction, wherein • the stator body (5) is formed from a laminated sheet stack (8) having a plurality of electric sheets (9), • and the stator body (5) is fixed in or on a receiving structure (10), wherein a plurality of the electric sheets (9) each have fixing means (11) formed integrally therewith, which, under the influence of an axial force (12) acting on the stator body (5) during assembly at room temperature in or on the receiving structure (10), bring about a transverse press connection between the plurality of electric sheets (9) having fixing means (11) and the receiving structure (10), with the result that the stator body (5) is fixed in or on the latter in its state mounted in or on the receiving structure (10), wherein the fixing means (11) project radially from the stator body (5) and, when inserted into the receiving structure (10), have an excess with respect to the latter, characterized in that the sheet stack (8) has a first group (16) of electric sheets (9), a second group (17) of electric sheets (9) and a third group (18) of electric sheets (9), wherein the first group (16) of electric sheets (9) is positioned in or on the receiving structure (10) with play, the second group (17) of electric sheets (9) is positioned in or on the receiving structure (10) with play, wherein the play (19) of the second group (17) of electric sheets (9) relative to the receiving structure (10) is smaller than the play (20) of the first group (16) of electric sheets (9) relative to the receiving structure (10), the third group (18) of electric sheets (9) has the fixing means (11), wherein in each case one electric sheet (9) of the third group (18) of electric sheets (9) bears on both sides in each case on one electric sheet (9) of the first group (16) of electric sheets (9), and in each case one electric sheet (9) of the second group (17) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9).Stator (1) according to Claim 1, wherein the plurality of electrical laminations (9) having fixing means (11) are substantially identically shaped.Stator (1) according to Claim 1 or 2, wherein the fixing means (11) is designed as a circular shaped deformation (14) which projects in the axial direction out of the plane (13) of an electric sheet (9).Stator (1) according to one of the preceding claims, wherein the fixing means (11) are formed as circular ring sections (15).Stator (1) according to one of the preceding claims, wherein the first group (16) of electric sheets (9), the second group (17) of electric sheets (9) and the third group (18) of electric sheets (9) consist of substantially identically shaped electric sheets (9) which are arranged in the stack of sheets (8) rotated with respect to one another.The stator (1) according to any one of the preceding claims, wherein the receiving structure (10) is a housing, a stator carrier or a shaftMethod for producing a stator (1) of an electric machine (2), comprising the following steps: • providing a receiving structure (10) in or on which a stator body (5) can be fixed, • providing a stator body (5) having a multiplicity of stator teeth (6) arranged in a circumferentially distributed manner and stator grooves (7) formed between the stator teeth (6) and extending through the stator body (5) in the axial direction, wherein the stator body (5) is formed from a laminated sheet stack (8) having a plurality of electric sheets (9), wherein a plurality of the electric sheets (9) each have fixing means (11) formed integrally therewith, which, under the influence of an axial force (12) acting on the stator body (5) during the mounting in or on the receiving structure (10), bring about a transverse press connection between the plurality of electric sheets (9) having fixing means (11) and the receiving structure (10), with the result that the stator body (5) can be fixed in or on the receiving structure (10) in its state mounted in or on the latter, wherein the fixing means (11) project radially from the stator body (5) and, when it is inserted into the receiving structure (10), have an excess dimension with respect to the latter, wherein the sheet stack (8) has a first group (16) of electric sheets (9), a second group (17) of electric sheets (9) and a third group (18) of electric sheets (9), wherein the first group (16) of electric sheets (9) is positioned in or on the receiving structure (10) with play, the second group (17) of electric sheets (9) is positioned in or on the receiving structure (10) with play, wherein the play (19) of the second group (17) of electric sheets (9) relative to the receiving structure (10) is smaller than the play (20) of the first group (16) of electric sheets (9) relative to the receiving structure (10), the third group (18) of electric sheets (9) has the fixing means (11), wherein in each case one electric sheet (9) of the third group (18) of electric sheets (9) bears on both sides in each case on one electric sheet (9) of the first group (16) of electric sheets (9), and in each case one electric sheet (9) of the second group (17) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9), • mounting the stator body (5) in or on the receiving structure (10) at room temperature.Rotor (23) for an electric machine (2), in particular for an electric machine (2) within a drive train (3) of a motor vehicle (4), comprising • a rotor body which is formed from a laminated sheet stack (8) having a plurality of electric sheets (9), • and the rotor body is fixed in or on a rotor shaft, wherein a plurality of the electric sheets (9) each have fixing means (11) which are formed integrally therewith and which bring about a transverse press connection between the plurality of electric sheets (9) having the fixing means (11) and the rotor shaft under the influence of an axial force (12) acting on the rotor body during the assembly at room temperature on the rotor shaft, such that the rotor body is fixed thereon in its state mounted on the rotor shaft, wherein the fixing means (11) project radially from the stator body (5) and, when inserted into the receiving structure (10), have an excess size with respect to the latter, characterized in that the stack of laminations (8) has a first group (16) of electrical laminations (9), a second group (17) of electrical laminations (9) and a third group (18) of electrical laminations (9), wherein the first group (16) of electrical laminations (9) is positioned in or on the receiving structure (10) with play, and the second group (17) of electrical laminations (9) is positioned in or on the receiving structure (10) with play, wherein the clearance (19) of the second group (17) of electric sheets (9) with respect to the receiving structure (10) is smaller than the clearance (20) of the first group (16) of electric sheets (9) with respect to the receiving structure (10), the third group (18) of electric sheets (9) has the fixing means (11), wherein in each case one electric sheet (9) of the third group (18) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9), and in each case one electric sheet (9) of the second group (17) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9).Method for producing a rotor (23) of an electric machine (2), comprising the following steps: • providing a rotor shaft in or on which a rotor body can be fixed, • providing a rotor body which is formed from a laminated sheet stack (8) having a plurality of electric sheets (9), wherein a plurality of the electric sheets (9) each have fixing means (11) which are formed integrally with said electric sheets and which, under the influence of an axial force (12) acting on the rotor body during the mounting on the rotor shaft, bring about a transverse press connection between the plurality of electric sheets (9) having the fixing means (11) and the rotor shaft, such that the rotor body can be fixed in or on the rotor shaft in its state mounted on the rotor shaft, wherein the fixing means (11) project radially from the rotor body (5) and, when being inserted into the receiving structure (10), have an excess size with respect to the latter, wherein the stack of sheets (8) has a first group (16) of electric sheets (9), a second group (17) of electric sheets (9) and a third group (18) of electric sheets (9), wherein the first group (16) of electric sheets (9) is positioned in or on the receiving structure (10) with play, the second group (17) of electric sheets (9) is positioned in or on the receiving structure (10) with play, wherein the play (19) of the second group (17) of electric sheets (9) with respect to the receiving structure (10) is smaller than the play (20) of the first group (16) of electric sheets (9) with respect to the receiving structure (10), the third group (18) of electric sheets (9) has the fixing means (11), wherein in each case one electric sheet (9) of the third group (18) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9), and in each case one electric sheet (9) of the second group (17) of electric sheets (9) bears on both sides in each case against an electric sheet (9) of the first group (16) of electric sheets (9), • mounting the rotor body on the rotor shaft at room temperature.Electric machine (2), in particular for a drive train (3) of a motor vehicle (4), comprising a stator (1) according to one of Claims 1-6 and / or a rotor (23) according to Claim 8.

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