Electric machine having coupling device and method for assembling such electric machine

Abstract

The invention relates to an electric machine (1) having: a stator (2) with a stator body (3) and a multi-phase stator winding (4) having at least one winding end (7) for each phase, the stator (2) defining a stator axis (100); a housing (9), the housing (9) being divided into a receiving region (12) for receiving the stator body (3) in a rotationally fixed manner and an interface region (13) for electrically connecting the stator winding (4); a coupling device (14) having, for each phase, at least one busbar (15a, 15b, 15c) for electrically contacting the winding end (7) with the high-voltage connection, and having an electrically insulating insulating member (17) by means of which the busbar (15a, 15b, 15c) is mounted on the housing (9); and a positioning device (20) for positioning the winding ends (7) correctly on the busbars (15a, 15b, 15c), the insulating component (17) having at least one centering section (23a, 23b) by means of which the coupling device (14) and the positioning device (20) are jointly centered on the housing (9) into a final position.

Description

TECHNICAL FIELD

[0001] The invention relates to an electric machine having the features of the preamble of claim 1. Furthermore, the invention also relates to a method for assembling the electric machine. BACKGROUND

[0002] Electric machines are known, whose stator windings are contacted by means of a wiring assembly with a high-voltage interface, for example a power electronics, in order to apply a voltage to the individual phases of the stator windings. Due to installation space restrictions, it is known from the prior art to arrange the wiring assembly outside the housing of the electric machine instead of inside the housing. The wiring assembly can here be fastened, for example, axially on the side of the housing facing away from the stator.

[0003] Document DE 10 2019 133 674 A1 discloses an electric machine comprising a rotor and a stator, wherein the stator comprises a stator body which carries at least one respective winding of at least one phase, wherein the respective phase winding or at least one winding of the respective phase winding is in electrically conductive connection with a respective contact bridge, which connects the respective winding with an assigned current source and / or current sink. The respective winding and the contact bridge connected thereto each end in a conductor section which extends away from the stator body in the axial direction of the electric machine, wherein the conductor sections are in electrically conductive connection with one another. By fastening a fastening section of the respective contact bridge on the housing body which accommodates the stator and / or on the current source and / or current sink, which in turn is fastened on the housing, via an insulating element or directly, said fastening section is arranged in a position-fixed manner with respect to the housing. SUMMARY

[0004] It is an object of the present invention to provide an electric machine of the type mentioned at the outset, which is characterized by simple assembly and robust construction. Furthermore, it is a further object of the present invention to propose a corresponding method for assembling the electric machine.

[0005] This object is achieved by an electric machine having the features of claim 1 and by a method having the features of claim 15. Further design features and advantages according to the invention result from the respective subclaims and from the following description and the drawings.

[0006] The subject of the invention is an electric machine, which is in particular used and / or suitable for generating an electric drive torque, in particular a traction torque, of a vehicle. The electric machine is for example a so-called traction machine. The electric machine can be integrated into an electric drive train, preferably into an electric axle. The electric drive train can be a purely electric or hybrid drive train. Preferably, the electric machine is an internal rotor electric machine.

[0007] To this end, the electric machine has a stator and a rotor, which is preferably arranged radially inside the stator, the rotor defining an axis of rotation. The stator has a stator body and a multiphase stator winding, which has at least one or exactly one winding end per phase. The stator winding is preferably arranged on and / or partially accommodated in the stator body of the stator. In particular, the stator winding has exactly three phase windings for contacting the power electronics, wherein each phase winding comprises at least one sub-strand. Preferably, each sub-strand is formed by a plurality of plug-in coils. The plug-in coils can have at least one, preferably exactly two contact points on at least one side, by means of which the plug-in coils are connected to one another in pairs to form the respective sub-strand. In particular, the stator body is a ring-shaped lamination stack. In particular, the stator body has a plurality of grooves each extending along a longitudinal axis, wherein each plug-in coil passes through at least one, preferably exactly two grooves spaced apart in the circumferential direction. The stator winding is preferably a hairpin winding or a wave winding. To this end, the plug-in coils can be hairpins, I-pins or D-pins. In particular, the rotor mainly comprises a rotor shaft and a rotor body connected non-rotatably to the rotor shaft. The rotor is supported by the rotor shaft in a manner rotatable relative to the stator, wherein the rotor body is arranged radially inside the stator body. In particular, the stator axis is defined by the axis of rotation of the rotor.

[0008] The electric machine has a housing, which is in particular divided in the axial direction of the stator axis into an accommodation region for accommodating the stator body non-rotatably and an interface region for electrically contacting the stator winding. In principle, the accommodation region and the interface region can be spatially separated from one another. However, the accommodation region and the interface region are preferably spatially connected to one another.

[0009] The electric machine has a coupling device, which is in particular for and / or suitable for wiring the sub-strands or plug-in coils. In particular preferably, the coupling device is arranged on the end side of the stator facing away from the contact points in the axial direction of the stator axis. The coupling device has at least one or exactly one busbar per phase, which is used and / or suitable for electrically contacting the winding end with the high-voltage interface. In particular, the winding end is aligned in the axial direction of the stator axis to the interface region and in electrically conductive contact with the respective associated busbar. The busbar is preferably supported on the respective winding end in the radial direction of the stator axis here. In other words, the busbar is supported radially outside the winding end. Preferably, the winding end extends parallel and / or identically directed with respect to the stator axis. In particular, the winding end exceeds the winding head of the stator winding in the axial direction at least at one axial end side. Preferably, the high-voltage interface is an alternating high-voltage interface of the power electronics. "High voltage" here means an alternating voltage of 30 V and above.

[0010] The coupling device has an electrically insulating insulation member, wherein the busbars are fitted on the housing via the insulation member. In particular, the busbars are accommodated in or at the insulation member electrically insulated from one another. In principle, the busbars can be accommodated partially in the insulation member. Alternatively or as an optional supplement, the busbars are partially embedded in the insulation member. The insulation member can be made of any electrically insulating material, preferably of plastic. In particular, the arrangement of the busbars in the insulation member is such that at least the regions of the busbars that are in electric contact with the winding ends, more precisely the high-voltage connections, are exposed.

[0011] It is proposed within the framework of the invention that the electric machine has a positioning device for and / or adapted to position the winding ends correctly on the busbars. The insulation member has at least one or exactly one centring section, via which the coupling device and the positioning device are jointly centred to the final position on the housing. The positioning device and the coupling device are preferably two separate components, which are correctly centred and / or connected to one another via the at least one centring section. In particular, the positioning device and the coupling device are fixed and / or can be fixed on the housing in a unique orientation via the at least one centring section. The positioning device serves, inter alia, to capture the individual winding ends when the positioning device is fitted and subsequently to pre-align them with the respective conductor sections. When the coupling device is subsequently fitted, the individual winding ends are aligned such that they lie against and / or in contact with the respective busbar.

[0012] The invention is based on the recognition that the winding ends are axially lengthened in order to come into contact with the busbars. They are therefore affected by the vibrations of the drive train and can be torn away from the busbar as a result of the dynamic loads at the contact points. This can lead to the electric machine being taken out of operation. Furthermore, for technical reasons, the positioning device cannot always be integrated into the insulation member of the coupling device.

[0013] The advantage of the invention is that the winding ends are supported and guided by the positioning device and are thus held in a predetermined final position. The winding ends can thereby be protected from the effects of the vibrations of the drive train and thus from possible cracks or tearing away from the busbar. Furthermore, the centring section also significantly simplifies the fitting, since the two components (connection, positioning device) are centred to the predetermined final position on the housing by means of the centring section when fitted. Furthermore, since the orientation of the winding ends is always adjusted by means of the centring of the positioning device when fitted, the deviation of the winding ends from the final position can be much greater.

[0014] In one specific embodiment it is proposed that in the final position the positioning device is fixed on the centring section in the axial direction, in the radial direction and in the tangential direction of the stator axis. Preferably, within the frame of the stator assembly the positioning device and the coupling device are successively assembled on the stator winding, wherein during assembly of the coupling device the positioning device and the coupling device are centred relative to each other into the final position by means of the centring section. In particular, in the installed condition the positioning device is supported in the axial direction of the stator axis in a form-fitting manner on the coupling device, preferably on the insulating member, on the one hand, and on the housing, on the other hand. In particular, in the installed condition the positioning device is supported in the radial direction and in the tangential direction, i.e. in the circumferential direction, of the stator axis in a form-fitting manner on the centring section. Preferably, the insulating member has at least two or exactly two centring sections which are spaced apart from each other in the radial direction and / or in the tangential direction, i.e. in the circumferential direction, of the stator axis. Thereby, a centring connection is proposed which is very convenient and cost-effective to implement and at the same time the positioning device and the coupling device can be conveniently assembled or centred.

[0015] In one specific design it is proposed that the housing has at least one or exactly one centring receptacle in which the centring section is locally, precisely fittingly accommodated in the radial direction and in the tangential direction of the stator axis. During assembly of the coupling device the centring section is inserted into the centring receptacle, preferably in the axial direction of the stator axis, so that the centring section is accommodated in the centring receptacle in a gap-free manner in the radial direction and in the tangential direction. Preferably, the centring section is accommodated in the centring receptacle in a form-fitting and / or force-transmitting manner in the radial direction and / or in the tangential direction, i.e. in the circumferential direction, of the stator axis. Optionally, the centring receptacle and / or the centring section can have an insertion chamfer by means of which the centring section is inserted into the centring receptacle as axial movement progresses. The centring section is composed, for example, of a centring protrusion, a centring peg, a centring post, a centring pin or the like which is oriented in the axial direction. The centring receptacle is formed, for example, by an opening, a hole, a recess or the like which is complementary to the centring section. Thereby, centring of the insulating member on the housing is ensured in particular conveniently and reliably.

[0016] In another design it is proposed that the positioning device has a centering penetration, in which the centering section is accommodated locally, precisely in the radial direction and in the tangential direction of the stator axis. When fitting the coupling device, the centering section is preferably guided into the centering accommodation through the centering penetration in the axial direction of the stator axis, so that the centering section is accommodated without play in the radial direction and in the tangential direction in the centering penetration and in the centering accommodation at least in the final position. Preferably, the centering section is accommodated in the centering penetration in the radial direction and / or in the tangential direction, i.e. in the circumferential direction of the stator axis, in a form-fit and / or force-fit manner. Alternatively, the centering penetration can have an insertion chamfer, through which the centering section is inserted into the centering penetration as the axial movement progresses. The centering penetration is formed, for example, by an opening, a hole, a lug or a similar structure which is complementary to the centering section. Thereby, it is ensured that the positioning device is particularly easily and reliably centered on the centering section.

[0017] In an improvement it is proposed that the centering section has two different centering diameters, wherein a first centering diameter is used and / or adapted for centering on the housing and a second centering diameter is used and / or adapted for centering on the positioning device. In particular, the first centering diameter has a diameter which is complementary to the centering accommodation and the second centering diameter has a diameter which is complementary to the centering penetration. In short, the centering section has a stepped diameter. In particular, the transition from the first centering diameter to the second centering diameter is formed by a further insertion chamfer. By means of the different diameters high fitting tolerances and component tolerances in the radial direction and in the tangential direction of the stator axis between the coupling device, the positioning device and the housing can be compensated during fitting.

[0018] In another specific implementation it is proposed that the first centering diameter is smaller than the second centering diameter, so that the first centering diameter is accommodated with a radial clearance in the centering penetration in a pre-centering position. In particular, the pre-centering position is to be understood as meaning the axial position when the coupling device is inserted into the centering penetration of the positioning device with the first centering diameter. The difference between the first centering diameter and the second centering diameter is, for example, greater than 0.5 mm, preferably greater than 1 mm, in particular greater than 5 mm. Due to the radial clearance, the coupling device and the positioning device can move radially relative to one another, so that an easy insertion into the centering accommodation is facilitated. By pushing the centering section further into the centering accommodation, in addition the winding ends are overlapped with the busbar, so that the winding ends are radially bound in the positioning device.

[0019] In another implementation it is proposed that the positioning device has a positioning section for each busbar, which is used and / or adapted to position the winding end in the correct position on the associated busbar. To this end, the positioning section has a guide channel through which at least one or exactly one of the winding ends is guided in the radial direction and / or tangential direction of the stator axis in the correct position to the respective associated busbar. In particular, the winding end is guided and / or forced in a straight line in the axial direction of the stator axis through the respective guide channel. Preferably, the winding end is accommodated in the respective guide channel in a form-fitting manner in the radial direction and / or tangential direction, i.e. circumferential direction. To this end, the guide channel preferably has a constant, in particular rectangular, opening cross section through which the at least one winding end partially passes. Thereby, an insulation means is proposed which guarantees the reliable positioning of the winding end relative to the respective busbar. Thereby, the assembly process, in particular the joining process, of the winding end to the respective busbar is significantly simplified.

[0020] In another specific implementation it is proposed that in the end position the winding end is supported in the radial direction in a force-transmitting manner both on the respective associated guide channel and on the respective associated busbar. In short, in the end position of the coupling device and the positioning device the winding end is clamped or bound between the respective busbar and the guide channel. As an optional supplement, in the end position the winding end is at least supported in the tangential direction, i.e. circumferential direction, in the guide channel in a form-fitting manner. Thereby, the winding end is guided without play by the guide channel to the respective busbar, whereby the assembly reliability is significantly improved, in particular during the joining process. Clamping the winding end on the coupling device can in addition suppress vibrations of the winding end.

[0021] In an embodiment, it is proposed that the positioning sections each have at least one or exactly one insertion ramp, through which the winding end portions are inserted and / or can be inserted in position into the respective associated guide channel. In particular, during assembly of the coupling device, the winding end portions are oriented in position in the radial direction and / or in the tangential direction of the stator axis by means of the insertion ramps and are inserted or passed into the respective guide channel. Preferably, the insertion ramps are formed by at least one inclined face which extends obliquely from the insertion opening in the direction of the guide channel on the radially outer side and / or on the radially inner side, which is used and / or is suitable for inserting the respective winding end portion in position in the radial direction. As an alternative or in addition, the insertion ramps are formed by at least one further inclined face which extends obliquely from the insertion opening in the direction of the guide channel in the circumferential direction, which is used and / or is suitable for inserting the respective winding end portion in position in the tangential direction. During assembly, the winding end portions can be slid along the inclined faces, during which the winding end portions are simultaneously aligned in the radial and / or tangential direction in the direction of the guide channel. Particularly preferably, the positioning sections are designed funnel-shaped and / or have an opening diameter which converges towards the guide channel. Thus, it can be ensured by means of the insertion ramps that the winding end portions can be inserted easily and reliably into the respective guide channel. The converging cross-sectional variation can very conveniently compensate for large positional tolerances of the winding end portions, i.e. the winding end portions can be easily captured during assembly.

[0022] In another embodiment, it is proposed that the insulation member has at least one or exactly one fastening section which is used and / or is suitable for fastening the insulation member on the housing of the electric machine. In particular, the fastening section is used for accommodating and / or guiding a fastening element, wherein the insulation member is fastened and / or can be fastened on the housing inner side of the housing by means of the fastening element in the end position. To this end, the fastening section can have a fastening opening through which the fastening element is fixed and / or can be fixed in a form-fitting and / or force-transmitting manner in a corresponding fastening accommodation of the housing. Particularly preferably, the fastening element is a fastening screw, in which case the fastening accommodation accordingly has an internal thread for accommodating the fastening screw. In principle, the fastening opening can be formed by a through-hole formed in the fastening section. Alternatively, however, the fastening opening can also be formed by a separate bushing, sleeve or similar component which is fixed firmly in the fastening section. Alternatively, however, the fastening section can also have a fastening accommodation, in which case the fastening element passes through a fastening opening formed in the housing. To this end, the fastening accommodation can be formed, for example, by a threaded bushing, a nut or similar component which is fixed firmly in the fastening section.

[0023] According to the embodiment, it is proposed that the fastening section has an abutment face, by means of which the insulation member is supported on the housing in the axial direction of the stator axis. In particular, the housing has a preferably planar mating face, by means of which the insulation member is at least locally, preferably planarly, abutted against the abutment face in the axial direction. It is particularly preferred that the abutment face extends in the radial plane of the stator axis and / or parallel to the mating face. In particular, the abutment face is arranged adjacent to the fastening opening or the fastening receptacle. In particular, the abutment face is formed by an annular face which surrounds the fastening opening or the fastening receptacle. Thus, a final position of the insulation member in the axial direction is defined by the abutment face. Thereby, an insulation member is proposed, which is characterized by a particularly reliable assembly or fastening of the coupling device. As an optional supplement, the insulation member can have at least one further abutment face, by means of which the insulation member is supported on the housing in the axial direction of the stator axis. This further abutment face can be arranged on another fastening section or on an arbitrary location on the underside of the insulation member, preferably spaced apart from the abutment face described above. Thereby, a particularly stable fastening of the coupling device to the housing is ensured by means of the at least two abutment faces.

[0024] In another specific embodiment, it is proposed that the insulation member has at least one or exactly one fixing section for and / or adapted to fix the insulation member to the busbar, respectively. In particular, the fixing section serves to firmly fix the respective busbar to the insulation member. To this end, the busbar is fixed to the insulation member in the axial direction and / or in the radial direction of the stator axis by means of the respective fixing section in a form-fit and / or force-fit manner. Preferably, the busbar and the insulation member are connected to each other in one piece by means of the fixing section, preferably forming a common structural unit. In particular, the fixing section can interact with a fixing receptacle formed on the busbar, respectively. In principle, the busbar can be fixed to the insulation member in the axial direction of the stator axis by means of the fixing section. Alternatively, the busbar is fixed to the insulation member in the radial direction and / or in the tangential direction of the stator axis by means of the fixing section. In principle, the busbar can be detachably fastened to the insulation member by means of the fixing section, for example by means of a snap connection. Preferably, however, the busbar is non-detachably, i.e. permanently, fastened to the insulation member by means of the fixing section, for example by means of a rivet or a hot-pressed connection. Thereby, the busbar can be particularly easily and firmly fastened to the insulation member, which can be achieved without additional fastening means, for example screws.

[0025] In an improvement it is proposed that the middle section and the fastening section are formed from a common material section. Alternatively or as an optional supplement it is proposed that the middle section and the fastening section are formed from a common material section. In other words, the middle section and the fastening section and / or the fixing section are integrally formed, in particular from a common plastic injection-molded part. In particular preferably, the entire insulation member is formed from exactly one material section, that is to say is integrally constructed. Thus, the insulation member can be manufactured integrally at low cost.

[0026] In a further implementation it is proposed that the stator winding has a further winding end for each phase, more precisely for each phase winding. Preferably, the stator winding has exactly three phase windings, which each have two winding ends. The connection device has a further busbar for and / or adapted to form a star contact of the further winding end, wherein the further busbar is arranged on a lower side of the insulation member, which faces away from one of the busbars. The phase windings can be wired to one another by means of the star contact to form a star circuit. Preferably, the further winding ends extend alternately between the winding ends and / or parallel to one another and / or in the same direction in the axial direction of the stator axis. Preferably, the further busbar forms a connection ring, through which the further winding ends are electrically conductively connected to one another. Thus, the star contact of the further winding ends of the three phase windings, which contact one another, is formed by the connection ring. Preferably, the busbar and the further busbar, that is to say the connection ring, are fastened to the insulation member electrically insulated from one another. In particular preferably, the insulation member has at least one further fixing section for fixing the further busbar on the insulation member and / or the positioning device has a further positioning section for positioning the further winding ends positionally correctly on the further busbar. The further fixing section and the other fixing sections and / or the further positioning section and the other positioning sections can be identically constructed. Thus, a connection device is proposed, which as a preassembled structural unit can be handled particularly conveniently during assembly.

[0027] In another design it is proposed that the housing has a housing base body and at least one bearing cover, which together delimit an interface region of the housing, wherein the coupling device and the positioning device are collectively centered to the final position on the housing base body by means of the centering section. In particular, the housing base body and the at least one bearing cover are connected to one another in the axial direction of the stator axis. Here, the housing base body can be open on one side or on both sides, while the bearing cover closes one side of the housing base body. Preferably, at least the stator body is arranged completely in a receiving region within the housing base body and is connected to the housing base body in a rotationally fixed manner. Particularly preferably, the rotor shaft passes through the stator body and is supported on the bearing cover in a rotationally fixed manner on the end side. On the other side, the rotor shaft can be supported in a rotationally fixed manner on the housing base body or on another bearing cover. Particularly preferably, the housing base body has at least one centering receptacle. In particular, the positioning device and the coupling device are centered in the radial direction and / or in the tangential direction of the stator axis by means of the centering section and are fixed in position on the housing base body in the axial direction by means of the fastening section. In principle, the coupling device and the positioning device are fixed on the housing base body in a form-fit manner, in particular by means of the centering section, and / or in a force-fit manner, in particular by means of at least one fastening element. Thereby, a solution is proposed which allows for a convenient and reliable fastening of the insulating component in the interface region.

[0028] A further subject of the present application relates to a method of assembling an electric machine as already described hereinbefore, wherein:

[0029] - assembling the stator into the housing;

[0030] - preassembling the positioning device on the winding end, wherein the winding end is pre-aligned by means of the positioning device;

[0031] - assembling the coupling device on the winding end, wherein the coupling device and the positioning device are collectively centered to the final position on the housing by means of the centering section.

[0032] In particular, the stator is assembled into the housing base body and is then provided as a preassembled structural unit. Within the final assembly frame, the positioning device and the coupling device can then be assembled on the stator winding one after the other. For this purpose, the positioning device is pushed on or plugged onto the winding end by means of the positioning section. The coupling device can then be oriented substantially coaxially with respect to the centering through-portion and / or the centering receptacle by means of at least one centering section.

[0033] In a further method step, the coupling device is transferred to the pre-centered position in the axial direction of the stator axis. For this purpose, the coupling device is inserted into the centering through-portion by means of the centering section, in particular by means of the first centering diameter, during which the coupling device and the positioning device are pre-centered with respect to one another.

[0034] The coupling device is then transferred into a final centred position corresponding to the final position in the axial direction of the stator axis. To this end, the coupling device is inserted into the centring penetration using the centring section, in particular using the first centring diameter, during which the coupling device and the positioning device are centred relative to one another into the final position. During this, the coupling device is moved in the axial direction until the at least one fastening section lies against the housing, in particular the housing base body, by the abutment face and / or the second centring diameter of the centring section is accommodated in the centring penetration.

[0035] In a further method step, the coupling device can be fixed on the housing by means of the at least one fastening. Alternatively, after the coupling device and the positioning device have been fixed in the final position, the axial overhang of the winding end relative to the busbar can be shortened. To this end, the overhanging winding end and, if necessary, further winding ends are shortened to flush with the busbar. During this, the coupling device preferably serves as a cutting aid.

[0036] Alternatively, within the framework of the joining process, the winding end can be connected to the busbar in a material connection, preferably by means of laser welding or tungsten inert gas welding (WIG). Preferably, to this end the coupling device is held in the final position during the joining process by means of the fastening section and the centring section. BRIEF DESCRIPTION OF DRAWINGS

[0037] The application is explained further below with reference to the drawings. The drawings show:

[0038] Figure 1 A motor as an embodiment of the application is shown in a sectional view along the stator axis;

[0039] Figure 2 An axial plan view of the motor in Figure 1 is shown without a bearing cover;

[0040] Figure 3 A perspective view of the lower side of the coupling device of the motor in Figure 1 is shown;

[0041] Figure 4 A perspective view of the upper side of the coupling device in Figure 3 is shown;

[0042] Figure 5 A perspective view of the lower side of the positioning device of the motor in Figure 1 is shown;

[0043] Figure 6 The motor is shown in the same illustration as Figure 1 with the positioning device in an assembled condition;

[0044] Figure 7 The motor is shown in the same illustration as Figure 1The same figure shows the electric machine, wherein the coupling device is in an assembled condition;

[0045] Figure 8 The same figure shows the electric machine, wherein the coupling device is in an assembled condition; Figure 1 The same figure shows the electric machine, wherein the coupling device is in an assembled condition;

[0046] Figure 9 The same figure shows the electric machine, wherein the coupling device is in an assembled condition; Figure 8 The same figure shows the electric machine, wherein the coupling device is in an assembled condition;

[0047] Figure 10 The same figure shows the electric machine, wherein the coupling device is in an assembled condition; Figure 1 The same figure shows the electric machine, wherein the coupling device is in an assembled condition. DETAILED DESCRIPTION

[0048] Figure 1 An electric machine 1 is shown, which is used to generate an electric drive torque, in particular a traction torque for an electric axle of a vehicle. The electric machine is an internal rotor electric machine and for this has a stator 2 and a not shown rotor arranged radially inside the stator 2.

[0049] The stator 2 is formed mainly from a stator body 3 and a multiphase stator winding 4, wherein the stator body 3 carries the stator winding 4. For this, the stator body 3 has a plurality of grooves which are distributed in the circumferential direction and extend in the axial direction of a stator axis 100.

[0050] The stator winding 4 is formed from a plurality of plug-in coils 5, for example in the form of hairpin coils or straight needle coils, which are wired to one another in a specific pattern. Here, the plug-in coils 5 are arranged in the grooves, wherein a plurality of plug-in coils 5 are arranged per groove.

[0051] The stator winding 4 here has exactly three phase windings 6a, 6b, 6c, which each have two winding ends 7, 8, as is shown in Figure 2 The winding ends extend parallel to one another and / or identically directed in the axial direction of the stator axis 100 at the outer diameter of the stator winding 4. The phase windings 6a, 6b, 6c each comprise two sub-strands, for example, which are each formed from a plurality of plug-in coils 5.

[0052] The electric machine 1 has a housing 9, wherein the stator 2 and the rotor are arranged coaxially with respect to the stator axis 100 in the housing 9. Here, the stator axis 100 is defined by the rotational axis of the rotor. The housing 9 has a housing base body 10 and a not shown bearing cover, which are connected to one another in the axial direction of the stator axis 100. The housing base body 10 and the bearing cover here delimit an inner space 11 of the housing 9, which is divided into a receiving region 12 and an interface region 13 in the axial direction of the stator axis 100.

[0053] The accommodation region 12 serves for accommodating the stator 2 and the rotor, wherein the stator 2, more precisely the stator body 3, is connected in the accommodation region 12 to the housing base body 10 in a rotationally fixed manner. The rotor shaft can pass through the interior space 11 in the axial direction of the stator axis 100 and is supported in a rotationally fixed manner both on the base body housing 10 and on the bearing cover.

[0054] The interface region 13 serves for electrically coupling the stator winding 4, wherein for this purpose coupling means 14 are arranged in the interface region 13. The coupling means 14 serve for wiring the winding ends 7 to form a star circuit, wherein the coupling means 14 are formed mainly from three busbars 15a, 15b, 15c, as Figure 3 shown, a further busbar 16 designed as a connection ring, and an insulating member 17. The winding ends 7, 8 of the individual phase windings 6a, 6b, 6c here extend in the axial direction of the stator axis 100 into the interface region 13 and are respectively in electrically conductive connection with the busbars 15a, 15b, 15c or the busbar 16.

[0055] As Figure 2 shown, the busbars 15a, 15b, 15c respectively have a conductor section 18 for contacting the first winding end 7, and the further busbar 16 has three further conductor sections 19 for contacting the second winding end 8, wherein the star point of the second winding ends 8 of the three phase windings 6a, 6b, 6c contacting one another is formed by the further busbar 16. The coupling means 14 are arranged outside the winding ends 7, 8 in the radial direction of the stator axis 100 and are supported on the respective winding end 7, 8 by means of the conductor sections 18, 19. The winding ends 7, 8 can be connected inseparably to the respective conductor section 18, 19, for example in a materially bonded manner, preferably by means of a welded connection. The conductor sections 18 and the further conductor sections 19 are respectively a winding terminal tab which extends in the axial direction of the stator axis 100, i.e. in the same direction of pointing as the respective winding end 7, 8.

[0056] As Figure 1 and Figure 2 shown, the electric machine 1 has a positioning device 20 for positioning the winding ends 7, 8 in position on the respective conductor section 18, 19. For this purpose, as Figure 5As shown, the positioning device 20 has positioning sections 21a, 21b, and 21c for each winding end 7, and positioning sections 22a, 22b, and 22c for each additional winding end 8, through which the winding ends 7 and 8 are correctly positioned to their respective conductor sections 18 and 19. In the current example, the positioning device 20 thus has three positioning sections 21a, 21b, and 21c, which respectively accommodate the first winding ends 7 of the corresponding phase windings 6a, 6b, and 6c; and three additional positioning sections 22a, 22b, and 22c, which respectively accommodate the second winding ends 8 of the corresponding phase windings 6a, 6b, and 6c, wherein each positioning section 21a-c and 22a-c respectively accommodates two sub-strands.

[0057] Furthermore, in order to contact the connecting device 14, the winding ends 7 and 8 are axially extended into the interface region 13. Therefore, the winding ends are affected by vibrations of the transmission system and may loosen due to dynamic loads at the contact points of the corresponding conductor sections 18 and 19, which could cause the motor 1 to stop. The winding ends 7 and 8 are fixed by positioning sections 21a-c and 22a-c to resist the effects of transmission system vibrations and thus prevent possible disengagement at the contact points. For this purpose, the winding ends 7 and 8 are supported or clamped, at least radially, on one hand to their respective conductor sections 18 and 19, and on the other hand to their respective positioning sections 21a-c and 22a-c.

[0058] Due to such Figure 3 As shown, an additional busbar 16 is arranged, so for technical reasons, the positioning sections 21a-c and 22a-c cannot be integrated into the insulating member 17 of the connecting device 14. Therefore, the insulating member 17 and the positioning device 20 are two separate components that must be aligned relative to each other in the fixed final position.

[0059] like Figure 1 As shown, the insulating member 17 has two centering sections 23a and 23b that are spaced apart from each other, just as Figure 3 As shown, it is used to align the connecting device 14 and the positioning device 20 to their final positions on the housing base 10. For this purpose, the housing base 10 correspondingly has a centering receiving portion 24, and the positioning device 20 correspondingly has centering through portions 25a and 25b, as shown... Figure 5As shown, the corresponding centering sections 23a and 23b are guided into the centering receiving portion 24. In the correct final position, the two centering sections 23a and 23b are received in a form-fitting manner in the corresponding centering receiving portion 24 and the corresponding centering through portions 25a and 25b in the radial and tangential directions of the stator axis 100, so that the connecting device 14 and the positioning device 20 are aligned together to the final position on the housing base 10. The centering sections 23a and 23b are cross-shaped pins oriented in the axial direction of the stator axis 100, which are directly molded on the lower side of the insulating member 17.

[0060] like Figure 2 As shown, the insulating member 17 has fixing sections 26a, 26b, and 26c for each busbar 15a, 15b, and 15c, which are used to fix the corresponding busbars 15a, 15b, and 15c onto the insulating member 17. Here, each busbar 15a, 15b, and 15c has a fixing receiving portion 27 for accommodating the corresponding fixing section 26a, 26b, and 26c.

[0061] like Figure 3 As shown, the insulating member 17 has additional fixing sections 28a, 28b, and 28c for securing the additional busbars 16 to the insulating member 17. Each of the additional busbars 16 has an additional fixing receiving portion 29 for accommodating the corresponding additional fixing sections 28a, 28b, and 28c. The fixing sections 26a-c are formed by plastic protrusions oriented in the axial direction along the stator axis 100, passing through their respective fixing receiving portions 27 and 29 and being formed into a heat-filled profile by melting. This achieves a particularly convenient and cost-effective method of securing the busbars 15a, 15b, 15c and the additional busbars 16 to the insulating member 17.

[0062] Furthermore, the insulating member 17 has three spaced-apart fastening sections 30a, 30b, and 30c, through which the insulating member 17 can be fastened or secured to the housing base 10. The fastening sections 30a, 30b, and 30c each form a fastening opening 31, through which fasteners 32 are mounted. Figure 2 The fasteners 31, as shown, pass through these fastening openings and are fitted into fastening receptacles (not shown) formed in the housing base 10. The fastening openings 31 are through holes that, when the connecting device 14 is in its correct final position, are flush with and / or coincide with the fastening receptacles. The fastening openings 31 can be directly formed into the fastening sections 30a, 30b, and 30c, or they can be formed by bushings arranged non-rotatably in the respective fastening sections 30a and 30b. The fasteners 32 are, for example, fastening screws, in which case the fastening receptacles can be corresponding threaded holes.

[0063] likeFigure 1 and Figure 3 As can be seen, the fastening sections 30a, 30b, 30c each have a flat abutment face 33, against which the insulation member 17 abuts in axial direction of the stator axis 100 on a complementary mating face 34 of the housing base body 10. Here, the abutment face 33 is formed by a respective annular face which surrounds the fastening opening 31 and which extends in a radial plane of the stator axis 100.

[0064] As can be seen in Figure 4 , the busbars 15a, 15b, 15c each have a contact section 35 for coupling with a high-voltage interface. These contact sections 35 are used, for example, for electrical coupling with power electronics. The contact sections 35 are each external terminal lugs which extend in radial direction of the stator axis 100, i.e. in a radial plane of the stator axis 100. The busbars 15a-c, 16 are fastened in the insulation member 17 in electrical insulation from one another. For this purpose, the insulation member 17 and the positioning device 20 are each made of an electrically insulating material, for example plastic.

[0065] Furthermore, the insulation member 17 has a plurality of support sections 36a, 36b, 36c, 36d which extend between the busbars 15a, 15b, 15c. The support sections 36a, 36b, 36c, 36d serve, on the one hand, to prevent the busbars 15a, 15b, 15c from being twisted, so that they withstand the torques which occur in the process of establishing a threaded connection when coupled to a high-voltage interface. Furthermore, the support sections 36a, 36b, 36c, 36d also serve to safeguard the air gap and the creepage distance between the busbars 15a, 15b, 15c, that is to say to electrically insulate the busbars 15a, 15b, 15c from one another. The support sections 36a, 36b, 36c, 36d are each a spacer rib which is oriented in axial direction of the stator axis 100 and which is directly molded on the upper side of the insulation member 17.

[0066] Here, the centering sections 23a, 23b, the fixing sections 26a-c, 28a-c, the fastening sections 30a, 30b, 30c and the support sections 36a, 36b, 36c, 36d are made of a common material section. Thus, an insulation member 17 is proposed which can be made integrally, for example by means of plastic injection molding, in a simple and cost-effective manner.

[0067] As can be seen in Figure 5 , the positioning sections 21a-c, 22a-c and the centering penetrations 25a, 25b are made of a common material section. Here, the centering penetrations 25a, 25b are each formed by a lug which has a through-hole for guiding the respective centering section 23a, 23b.

[0068] As can be seen in Figure 5 and Figure 6As shown, positioning sections 21a-c and 22a-c each have a guide channel 37, through which the winding ends 7 and 8 pass in a straight line along the axial direction of the stator axis 100. The winding ends 7 and 8 are locally supported in the corresponding guide channels 37 in the radial and tangential directions, i.e., the circumferential directions, of the stator axis 100 in a form-fitting manner.

[0069] Furthermore, positioning sections 21a-c and 22a-c each have an insertion ramp 38 on the side facing the winding head. During assembly of the connecting device 14, this insertion ramp serves as an insertion aid for inserting the winding ends 7 and 8 into their respective guide channels 37. The winding ends 7 and 8 can undergo positional changes via the insertion ramp 38, thereby precisely pre-aligning with the connection points of the connecting device 14. This also compensates for manufacturing tolerances of the winding ends 7 and 8.

[0070] like Figure 6 As shown, the insertion ramps 38 are formed by inclined surfaces 39a and 39b, which extend from the insertion opening 40 at a constant angle toward the corresponding guide channel 37. Here, the inclined surfaces 39a and 39b are arranged opposite each other in the radial direction of the stator axis 100, and thus are used to correctly insert the winding ends 7 and 8. The funnel shape formed therefrom allows the winding ends 7 and 8 to be easily captured and correctly aligned with the corresponding conductor segments 18 and 19 when assembling the coupling device 14.

[0071] The following is for reference. Figures 6 to 10 The method for assembling motor 1 is described. Here, stator 2 is as follows: Figure 1 The stator 2 is shown to be assembled in the housing base 10, particularly in the receiving area 12, without the need for the connecting device 14 and the positioning device 20. For example, the stator 2 is forcibly pressed or joined to the housing base 10 to form a suitable size or stop.

[0072] In the first assembly step, such as Figure 6 As shown, the positioning device 20 is inserted into the winding ends 7 and 8, during which time the winding ends 7 and 8 pass through the corresponding insertion openings 40 and slide along the inclined surfaces 39a and 39b in the direction of the guide channel 37. For this purpose, the positioning device 20 must be guided radially inward or outward so as to capture the winding ends 7 and 8 by the insertion inclined surface 38. The positioning device 20 can then be inserted into the winding ends 7 and 8 in the axial direction, i.e., moved axially. Here, the winding ends 7 and 8 are in a position that is pre-aligned substantially correctly with the conductor sections 18 and 19.

[0073] Here, the positioning device 20 is pushed onto the winding ends 7 and 8 until the positioning device is axially attached to the housing base 10 through the centering through portions 25a and 25b. Figure 8and are oriented substantially coaxially with respect to the associated centering receptacle 24 of the housing base body 10.

[0074] In a second assembly step, the coupling device 14 is pre-positioned, as shown in Figure 7 , with its two centering sections 23a, 23b substantially coaxially with the centering receptacles 24 and then moved in axial direction into a pre-centering position, as shown in Figure 8 , in another assembly step. Here, the centering sections 23a, 23b are partially inserted into the respective centering through-penetrations 25a, 25b.

[0075] Figure 9 A detail view A of Figure 8 shows that the centering sections 23a, 23b have two different centering diameters 41a, 41b, respectively. The first centering diameter 41a is used for centering on the housing base body 10 and the second centering diameter 41b is used for centering on the positioning device 20. Here, the first centering diameter 41a has a smaller diameter than the second centering diameter 41b, wherein the centering receptacles 24 and the centering through-penetrations 25a, 25b have an opening diameter complementary to the centering diameters 41a, 41b, respectively.

[0076] In the pre-centering position, as shown in Figure 8 , the centering sections 23a, 23b with the first centering diameter 41a are accommodated in the respective centering through-penetrations 25a, 25b with a radial clearance. Due to this radial clearance, the coupling device 14 and the positioning device 20 can be displaced relative to each other or relative to the housing base body 10, so that the penetration of the centering sections 23a, 23b is facilitated. Furthermore, the conductor sections 18, 19 radially overlap the winding end portions 7, 8 in the final position, thereby binding them in the positioning device 20. The radial clearance in the pre-centering position at least partially eliminates the overlap, so that the coupling device 14 is easily axially moved.

[0077] Furthermore, it can be seen from Figure 9 that the centering sections 23a, 23b have an insertion chamfer 42 on the end side, respectively, and the centering through-penetrations 25a, 25b have another insertion chamfer 43, respectively, through which the centering sections 23a, 23b are inserted or centered into the respective centering through-penetrations 25a, 25b when transferred into the pre-centering position. Thereby, the centering can be further simplified.

[0078] By further axial displacement, the coupling device 14 is transferred into a final centering position, as shown in Figure 1As shown, during this time the centering sections 23a, 23b are further inserted into the respective centering receptacles 24, so that the coupling device 14 and the positioning device 20 are centered into the final position. The coupling device 14 is moved here in the axial direction until the abutment faces 33 of the fastening sections 30a, 30b, 30c abut against the mating faces 34 of the housing base body 10.

[0079] Figure 10 A detail view B is shown Figure 1 from which it can be seen that the centering sections 23a, 23b are received without play, i.e. with exact fit, in the respective centering receptacles 24 with a first centering diameter 41a and in the respective centering through- openings 25a, 25b with a second centering diameter 41b, whereby the coupling device 14 is centered into the final position in the radial direction and in the tangential direction of the stator axis 100. Here, the centering through-openings 25a, 25b are coaxial to the second centering diameter 41b, while the first centering diameter 41b is coaxial to the respective centering receptacle 24. Thereby, the coupling device 14 and the positioning device 20 are jointly centered into the final position on the housing base body 9. At the same time, the winding end portions 7, 8 are re-created with an overlap with the conductor sections 18, 19, whereby the insulation member 17 and the positioning device 20 and the winding end portions 7, 8 received therein are subjected to a position change, so that a clear constriction of the winding end portions 7, 8 is formed in the guide channel 37. By the resulting clamping, the mechanical properties, for example the vibration load, can be improved.

[0080] The coupling device 14 can then be fixed in the axial direction by means of the assembly fastening 32. Thereby, the coupling device 14 is held in the desired installation position during the subsequent assembly process. In the final position of the coupling device 14, the winding end portions 7, 8 can have an axial overhang or overlength relative to the conductor sections 18, 19, which is shortened to the height of the conductor sections 18, 19, i.e. flush with the conductor sections 18, 19, after the insulation member 17 is fixed on the housing base body 10. Thereby, axial tolerances between the coupling device 14 and the stator 2 can be easily compensated.

[0081] In a further assembly step, the conductor sections 18, 19 can then be welded to the respective associated winding end portions 7, 8 within the framework of the joining process, for example by means of laser welding or WIG welding. Here, the welding process is carried out in the housing 9, more precisely in the interface region 12.

[0082] List of reference signs:

[0083] 1 electric machine

[0084] 2 stator

[0085] 3 stator body

[0086] 4 stator winding

[0087] 5 plug-in coil

[0088] 6a-6c phase winding

[0089] 7 winding end

[0090] 8 further winding end

[0091] 9 housing

[0092] 10 housing base body

[0093] 11 inner space

[0094] 12 accommodation region

[0095] 13 interface region

[0096] 14 coupling device

[0097] 15a-15c busbar

[0098] 16 further busbar

[0099] 17 insulating member

[0100] 18 conductor section

[0101] 19 further conductor section

[0102] 20 positioning device

[0103] 21a-21c positioning section

[0104] 22a-22c further positioning section

[0105] 23a, 23b centering section

[0106] 24 centering accommodation

[0107] 25a, 25b centering through-passage

[0108] 26a-26c fixing section

[0109] 27a-27c fixing accommodation

[0110] 28a-28c further fixing section

[0111] 29a-29c further fixing accommodation

[0112] 30a-30c fastening section

[0113] 31 fastening opening

[0114] 32 fastening element

[0115] 33 abutment face

[0116] 34 mating face

[0117] 35 contact section

[0118] 36a-36d support sections

[0119] 37 guide channel

[0120] 38 insertion bevel

[0121] 39a, 39b inclined faces

[0122] 40 insertion opening

[0123] 41a, 41b centering diameters

[0124] 42 insertion chamfer

[0125] 43 further insertion chamfer

[0126] 100 stator axis

Claims

1. Electric machine (1), having: - a stator (2) having a stator body (3) and a multiphase stator winding (4) having at least one winding end (7) for each phase, wherein - a stator (2) defining a stator axis (100); - a housing (9), wherein the housing (9) is divided into an accommodation region (12) for accommodating the stator body (3) non-rotatably and an interface region (13) for electrically coupling the stator winding (4); - a coupling device (14) having, for each phase, at least one busbar (15a, 15b, 15c) for electrically contacting the winding end (7) with a high-voltage interface, and an electrically insulating insulation member (17) by means of which the busbar (15a, 15b, 15c) is fitted on the housing (9); characterized in that a positioning device (20) is provided for correctly positioning the winding end (7) on the busbar (15a, 15b, 15c), wherein the insulation member (17) has at least one centering section (23a, 23b) by means of which the coupling device (14) and the positioning device (20) are jointly centered on the housing (9) into a final position.

2. The electric machine (1) according to claim 1, characterized in that In the final position, the positioning device (20) is fixed between the coupling device (14) and the housing (20) in the axial direction of the stator axis (100) and on the at least one centering section (23a, 23b) in the radial and tangential direction of the stator axis (100).

3. The electric machine (1) according to claim 1 or 2, characterized in that The housing (9) has at least one centering accommodation (24), wherein the centering section (23a, 23b) is accommodated in the centering accommodation (24) in the radial and tangential direction of the stator axis (100) with a partial, positive fit.

4. The electric machine (1) according to any one of the preceding claims, characterized in that, The positioning device (20) has at least one centering passage (25a, 25b), wherein the centering section (23a, 23b) is accommodated in the centering passage (25a, 25b) in the radial and tangential direction of the stator axis (100) with a partial, positive fit.

5. The electric machine (1) according to any one of the preceding claims, characterized in that, The centering section (23a, 23b) has two different centering diameters (41a, 41b), wherein a first centering diameter (41a) is used for centering on the housing (9) and a second centering diameter (41b) is used for centering on the positioning device (20).

6. The electric machine (1) according to claims 4 and 5, characterized in that, The first centering diameter (41a) is smaller than the second centering diameter (41b), so that the first centering diameter (41a) is accommodated in the centering passage (25a, 25b) with a radial clearance in a pre-centering position.

7. The electric machine (1) according to any one of the preceding claims, characterized in that, The positioning device has, for each busbar (15a, 15b, 15c), a positioning section (21a, 21b, 21c) for positionally correct positioning of the winding end (7) on the busbar (15a, 15b, 15c), wherein the positioning section (21a, 21b, 21c) has a guide channel (37) through which the at least one winding end (7) is positionally correctly guided in the radial direction and / or tangential direction of the stator axis (100) to the respective associated busbar (15a, 15b, 15c).

8. The electric machine (1) according to claim 7, characterized in that In the end position, the winding end (7) is supported in a force-fitting manner in the radial direction on the respective associated guide channel (37) on the one hand and on the respective associated busbar (15a, 15b, 15c) on the other hand.

9. The electric machine (1) according to claim 7 or 8, characterized in that The positioning section (21a, 21b, 21c) has at least one insertion ramp (38) through which the winding end (7) is positionally correctly inserted and / or can be positionally correctly inserted into the respective associated guide channel (37).

10. The electric machine (1) according to any one of the preceding claims, characterized in that, The insulation member (17) has at least one fastening section (30a, 30b, 30c) for fastening the insulation member (17) on the housing (9), wherein the fastening section (30a, 30b, 30c) has an abutment face (33) on which the insulation member (17) is supported in the axial direction of the stator axis (100) on the housing (9) in the end position.

11. The electric machine (1) according to any one of the preceding claims, characterized in that, The insulation member (17) has, for each busbar (15a, 15b, 15c), at least one fastening section (26a, 26b, 26c) for fastening the busbar (15a, 15b, 15c) on the insulation member (17), wherein the busbar (15a, 15b, 15c) is fastened in a form-fitting and / or force-fitting manner on the insulation member (17) in the axial direction and / or radial direction of the stator axis (100) by the respective fastening section (26a, 26b, 26c).

12. The electric machine (1) according to claim 10 or 11, characterized in that The at least one centering section (23a, 23b) and the at least one fastening section (30a, 30b, 30c) and / or the at least one fastening section (26a, 26b, 26c) are formed from a common material section.

13. The electric machine (1) according to any one of the preceding claims, characterized in that, The stator winding (4) has, for each phase, a further winding end (8), and the coupling device (14) has a further busbar (16) for forming a star contact of the further winding end (8), wherein the further busbar (16) is arranged on a lower side of the insulation member (17) facing away from the busbars (15a, 15b, 15c).

14. The electric machine (1) according to any one of the preceding claims, characterized in that, The housing (9) has a housing base body (10) and at least one bearing cover, which together delimit an interface region (13) of the housing (9), wherein, in the final position, the coupling device (14) and the positioning device (20) are jointly centered on the housing base body (10) by the at least one centering section (23a, 23b).

15. Method for assembling an electrical machine (1) according to any one of the preceding claims, wherein: - a stator (2) is assembled into a housing (9); - a positioning device (20) is pre-assembled on the winding end (7), wherein the winding end (7) is pre-aligned by the positioning device (20); - the coupling device (14) is assembled on the winding end (7), wherein the coupling device (14) and the positioning device (16) are jointly centered on the housing (9) by at least one centering section (23a, 23b) into a final position.

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