Electric machine

Abstract

An electric machine (1) comprising a stator body (2) having several circumferentially distributed, axially extending stator slots (3) which extend radially along slot walls (6) between a radially outer end wall (4) and a slot opening (5), wherein the electric machine (1) has conductor elements (8), in particular in the form of a wave winding, which are arranged in the stator slots (3), wherein the conductor elements (8) are arranged in at least one stator slot (3) in a receiving device (7) enclosing the conductor elements (8), which is arranged in the stator slot (3) and is fixed in the stator slot (3) in the region of the end wall (4).

Description

The invention relates to an electric machine comprising a stator base body which has a plurality of stator slots distributed in the circumferential direction and running in the axial direction, which slots extend in the radial direction along slot walls between a radially outer end wall and a slot opening, wherein the electric machine has conductor elements, in particular in the form of a wave winding, which are arranged in the stator slots.Electric machines of the type mentioned at the beginning, which have a stator base body in which a plurality of stator grooves running in the axial direction are provided for receiving conductor elements, are known in principle from the prior art. For the introduction of the conductor elements or the arrangement of the conductor elements, in principle a plurality of variants are known, for example the introduction of so-called "hair pins", which are inserted through the stator grooves and are connected to one another in the region of so-called "end windings", the application of single-tooth windings, which are wound around the teeth formed by the stator grooves, and the introduction of the conductor elements as a so-called "wave winding", in which the conductor elements are connected together and are subsequently introduced as a "mat" from the radially inside into the stator grooves.In all the cases described, it is necessary to secure the conductor elements in the stator grooves or to delimit between the stator space, which is ultimately defined by the stator base body, and a rotor space lying radially inside the stator space. For this purpose, it is known, for example, to introduce a so-called split tube into the base body opening of the stator base body, which split tube separates the stator space from the rotor space. However, the production and the assembly of the can are complicated.The object of the invention is to specify an electrical machine which is improved in comparison with it, in which in particular the mounting or fastening of the conductor elements and / or the separation between the stator space and the rotor space is improved.The object is achieved by an electric machine having the features of claim 1. Advantageous embodiments are the subject matter of the dependent claims.As described, the invention relates to an electric machine, in particular an electric machine for a motor vehicle, which comprises a stator base body. The stator base body has a plurality of stator grooves distributed in the circumferential direction and running in the axial direction. The grooves extend in the radial direction along groove walls between a radially outer end wall and a radially inner groove opening. The definition of the directions or axes is referred to, within the scope of this application, a longitudinal axis or axis of symmetry, in particular the axis of rotation, of the electric machine. The axial direction extends along the axis of rotation or parallel thereto. The radial direction is perpendicular to the axis of rotation. Accordingly, the circumferential direction is aligned around the axis of rotation. In other words, the stator base body has a plurality of stator grooves which extend in the axial direction between a first axial end face of the stator base body and a second axial end face of the stator base body. The stator slots are open in the radial direction, i.e. their slot openings point toward the axis of rotation. The end wall of the stator grooves forms the "base" or "cover", i.e. that end of the stator grooves which lies opposite the groove opening and which delimits the stator groove on the outside in the radial direction. The end walls of the individual stator grooves therefore extend within the stator grooves along the axial extent or the entire axial length of the stator base body. In the circumferential direction, each stator slot is defined by slot walls. Radially on the outside, the slot walls are connected by the end wall in each stator slot or merge into one another there.The invention is based on the finding that the conductor elements of at least one stator slot are arranged in a receiving device which surrounds the conductor elements and is arranged in the stator slots and is fastened in the stator slot in the region of the end wall. In comparison with the can described with reference to the prior art, it is thus proposed to provide a receiving device for the at least one stator groove, in particular to provide a receiving device for each stator groove. The conductor elements to be introduced into the stator grooves are thus introduced into the receiving device and mounted together with the receiving device in the stator groove.The fastening of the receiving device lies in the region of the end wall, that is to say that portion of the stator slot which lies opposite the slot opening in the radial direction. The end wall is in particular that wall of the stator grooves which connects the groove walls radially outwards between them in the circumferential direction, i.e. forms the "base" or the "ceiling" of the stator grooves. Advantageously, all conductor elements can thus be introduced in groups into their stator grooves, namely in the receiving device enclosing them in groups. By fastening the receiving device in the region of the end wall, a return of the conductor elements radially inward and thus an exit from the stator grooves is prevented. Due to the arrangement of the fastening point or fastening section in the region of the end wall, further measures, for example in the region of the slot opening, are not required, so that an assembly of the conductor elements and the receiving devices is possible in an improved manner.The described electric machine can furthermore be further developed to the effect that the receiving device has at least one fastening means which is received, in particular in a form-fitting manner, in a fastening receptacle provided in the end wall. The fastening means can basically be designed in any desired manner and can be brought into engagement with the fastening receptacle provided in the end wall or can cooperate in such a way that the receptacle device is fastened in the stator groove in the assembled state. The fastened receiving device holds the conductor elements in the stator slot, so that they cannot "fall back" out of the stator slot. By means of positively locking the fastening, a particularly simple assembly process can be carried out, in which the receiving device is introduced into the stator grooves until the positive locking between the fastening means and the fastening receptacle is produced. In the simplest case, the receiving device is inserted into the stator groove until the connection is established, for example inserted.Furthermore, in the electric machine, it can be provided that the receiving device is opened in the direction of the end wall, in particular rectangular or U-shaped in cross section. The receiving device thus has an opening in the region of the fastening means, in particular a gap or a slot which extends in the axial direction along the entire receiving device. The receiving device can thus be placed over the group of conductor elements or the opening of the receiving device can be opened and the conductor elements can thus be introduced into the receiving device. The receiving device can then encompass the conductor elements. When the receiving device is introduced into the stator grooves, the opening lies on the end wall, so that the closed side of the receiving device faces the axis of rotation or the rotor space and thus lies on or in the region of the groove opening.The opening in the receiving device can also entail the advantage that a tempering medium can be guided from the radially outside into the receiving device and thus directly to the conductor elements. The receiving device can be plugged or clipped onto the conductor elements through the opening. The U-shaped profile allows the receiving device to be expanded for assembly around the conductor elements and then to be set back, wherein the receiving device engages around the conductor elements. The U-shaped profile can have connecting sections in the region of the end wall which are approximately in contact, wherein the gap or the slot is formed between the connecting sections. Finally, the U-shaped profile can thus also be embodied as rectangular and substantially correspond to the shape of the stator grooves.The receiving device can have latching hooks or snap hooks designed as fastening means. As described, the receiving device is advantageously fastened by being introduced into the stator grooves in such a way that the fastening means engage in the fastening receptacle in a positive-locking manner. For example, the receiving device is inserted into the stator groove, so that the latching hooks or snap hooks can latch or snap into the fastening receptacle. The receiving device can thus be designed as a "retaining clip".The electric machine can also have a temperature control device or be coupled to a temperature control device which has at least one temperature control channel running in the stator base body, wherein an outlet of at least one temperature control channel is arranged on or in the end wall of the stator grooves and connects the interior of the receiving device to the temperature control channel. According to the described embodiment, the temperature control channel can run in the stator base body in such a way that an outlet of the temperature control channel is guided into the stator groove, namely on or into the described end wall. As a result, temperature control medium can flow from the temperature control channel through the outlet into the stator groove and temperature control the conductor elements.Advantageously, the receiving device, as described above, can be opened, in particular slotted, in the direction of the end wall, so that the temperature control medium can enter the receiving device from the outlet and can be guided within the receiving device. For example, starting from the outlet, the temperature control medium can be guided along the receiving device in the axial direction and thus flow around the conductor elements over their entire length in the axial direction within the stator base body. The receiving device seals the stator grooves such that the temperature control medium cannot leave the receiving device in the radial direction, since the receiving device is closed in the region of the groove opening, as described. The receiving device thus likewise forms a channel section for the temperature control medium, so that the temperature control medium can be guided along the conductor elements.According to a further embodiment of the electric machine, the outlet of the temperature control channel can be arranged in the region of the fastening receptacle, wherein temperature control medium within the receptacle moves the at least one fastening means of the receptacle device against the fastening receptacle. As described, the fastening means can be designed, for example, as snap hooks or latching hooks, which are in engagement in a fastening receptacle designed as a fastening opening. If tempering medium is guided into the receiving device, this has the result that the side walls of the receiving device, i.e. those side walls which are arranged parallel to the groove walls, are moved against the groove walls and thus bear firmly against the groove walls. At the same time, the fastening means in the fastening receptacle are moved against the fastening receptacle, for example outer surfaces of the fastening means on the inner surfaces of the fastening receptacle, so that a sealing effect is likewise achieved there. Finally, the sealing effect is improved by the internal pressure within the receiving device, since as a result of the receiving device pressing against the inner surfaces of the stator grooves and the fastening receptacle, temperature control medium does not pass, or does not pass significantly, into the gap between the receiving device and stator grooves, but rather is guided within the receiving device. In addition, a sealing element can be provided in the region of the fastening receptacle.As described, the receiving device extends within the stator grooves, so that the receiving device can surround the conductor elements. According to one embodiment of the electric machine, the at least one receiving device can project beyond the stator grooves in the axial direction. In other words, the receiving device is designed to be longer in the axial direction than the stator grooves, so that a protrusion of the receiving device with respect to the stator groove is produced. The receiving device can project in particular on both axial sides. A gap space which forms at the transition between the stator space and the rotor space can be sealed off as a result, since the temperature control medium which leaves the receiving device is guided beyond the gap space in the axial direction. In addition, a sealing element can be provided which is attached to the receiving device, in particular a sealing element at each of the two axial end regions, so that the gap space described can be sealed in an improved manner.According to a further embodiment of the electric machine, the at least one receiving device can be designed to electrically isolate the conductor elements from the stator base body. As described, the receiving device forms a casing or a housing for the conductor elements received in the receiving device. By the arrangement of the conductor elements within the receiving device, insulation of the conductor elements is effected by the receiving device. This contributes to meeting requirements with respect to HV safety. The receiving device thus increases an air and / or creepage distance with respect to the conductor elements. As a result, an insulation paper which is usually used and which is laid around the conductor elements is not required. The receiving device can be manufactured in particular from an insulating or non-current-conducting or poorly current-conducting material, for example from a plastic, or can comprise such a material.In addition to the electric machine, the invention relates to a motor vehicle which comprises an electric machine described above. The invention further relates to a method for producing an assembly for an electric machine, comprising a stator base body which has a plurality of stator grooves distributed in the circumferential direction and running in the axial direction, which extend in the radial direction along groove walls between a radially outer end wall and a groove opening, wherein conductor elements, in particular in the form of a wave winding, are surrounded by at least one receiving device and are introduced into the stator grooves, wherein the conductor elements of at least one stator groove are surrounded by the at least one receiving device and the at least one receiving device is fastened in the stator groove in the region of the end wall. As described, the conductor elements, in particular in the form of a wave winding, are advantageously surrounded in groups by a receiving device and introduced into the stator slots and fastened in the stator slot by the fastening means of the receiving device. The method can be used in particular for producing an electrical machine described above.All advantages, details and features described with respect to the electric machine can be completely transferred to the motor vehicle and the method.The invention is explained below on the basis of exemplary embodiments with reference to the figures. The figures are schematic representations and show: FIG. 1 shows a schematic illustration of a detail of an electric machine in a cross section according to a first exemplary embodiment; FIG. 2 shows a schematic illustration of a detail of the electric machine from FIG. 1 in a longitudinal section; FIG. 3 ashows a schematic illustration of a cross section of a receiving device of the electric machine of FIGS. 1, 2 ; FIG. 3 bshows a schematic illustration of a cross section of the receiving device of the electric machine from FIG. 3 awith conductor elements; FIG. 3 cshows a schematic illustration of an assembly process of a receiving device; FIG. 4 ashows a schematic representation of the receiving device of FIG. 3 ain perspective representation; FIG. 4 bshows a schematic illustration of the receiving device from FIG. 3 bin a perspective illustration; FIG. 5 shows a schematic illustration of a detail of an electric machine in a cross section according to a second exemplary embodiment; and FIG. 6 shows a schematic illustration of a detail of the electric machine from FIG. 5 in a longitudinal section.FIG. 1 shows an electric machine 1, in particular for a motor vehicle. The electric machine 1 can be part of an electric final drive of the motor vehicle or can generally be used as a traction drive for the motor vehicle. The electric machine 1 can thus be designed to output a torque for driving the motor vehicle.The electric machine 1 has a stator base body 2 which comprises a plurality of stator slots 3 distributed in the circumferential direction. The stator grooves 3 extend in the axial direction through the stator base body 2, as is illustrated for example in the longitudinal section in FIG. 2, As can be seen, the stator grooves 3 thus extend in the axial direction parallel to the longitudinal axis, in particular the longitudinal central axis, of the electric machine 1 or to the rotational axis of the electric machine 1, The stator grooves extend in the radial direction, i.e. perpendicular to the rotational axis or longitudinal axis or longitudinal central axis of the electric machine 1, from a terminating wall 4 to a groove opening 5. In the circumferential direction, each stator groove 3 is bounded by groove walls 6, which likewise extend substantially in the radial direction and axial direction.The electric machine 1 further comprises a receiving device 7 in which conductor elements 8 of the electric machine 1 are received within the stator slots 3. In other words, a group of conductor elements 8 is arranged in each stator slot 3, which are surrounded by a separate receiving device 7. In each stator slot 3 there is therefore provided a receiving device 7 which encloses the conductor elements 8 arranged there. The conductor elements 8 extend in the axial direction within the receiving device 7, so that the receiving device 7 closes the stator grooves 3 in the radial direction.Each receiving device 7 has a base section 9, which is arranged in the region of the groove opening 5. Furthermore, wall sections 10 of the receiving device 7 extend from the base section 9, which rest against the groove walls 6. In the region of the end wall 4 of the stator grooves 3, a fastening receptacle 11 is provided, in which fastening means 12, for example latching hooks or snap hooks, of the receptacle device 7 engage, in particular in a form-fitting manner. The receiving devices 7 delimit the stator grooves 3 from a rotor space adjoining within a base body opening of the stator base body 2. In particular, the conductor elements 8 are secured within the receiving devices 7 so that they remain within the stator slots 3. By providing the fastening means 12 radially on the outside and by fastening inside the fastening receptacle 11, a particularly simple assembly is possible, which is shown schematically stepwise in FIGS. 3 a- 3 c.FIG. 3 ashows schematically a cross section through an empty receiving device 7. As can be seen, the receiving device 7 has, as viewed in cross section, a substantially U-shaped profile which is designed to be open or slotted in the region of the fastening means 12, that is to say opposite the base section 9. The receiving direction 7 can thus be arranged around conductor elements 8 with the opening opposite the base section 9, for example plugged on or clipped on, as is illustrated in FIG. 3 b. The mounting of the receiving devices 7 on the conductor elements 8 joined together in groups can thus take place in the wound state, for example a wave winding or a so-called "broadband winding". Subsequently, the conductor elements 8 accommodated in the accommodation devices 7 can be fitted, in particular in groups, into the provided stator grooves 3, as is schematically shown in FIG. 3 cfor an accommodation device 7. In particular, all conductor elements 8 can be wound together in groups and inserted as a "mat" from radially inside to radially outside into the stator slots 3, so that the fastening means 12 of each receiving device 7 can be inserted into the fastening receptacle 11 provided in each stator slot 3.FIGS. 4 a, 4 b show the receiving device 7 illustrated in FIGS. 3 aand 3 bin a perspective view. As can be seen, the conductor elements 8 extend within the receiving device 7, so that the receiving device 7 encloses the conductor elements 8 at least within the stator base body 2. In addition, the receiving device 7 fulfills an insulation effect and a sealing effect. By surrounding the conductor elements 8 with the receiving device 7, which is formed from a poorly current-conductive, insulating or non-current-conductive material or comprises such a material, for example plastic, air and creepage distances can be increased. Specifically, the use of commonly used insulation paper can be dispensed with. As a result, direct contact of the conductor elements 8 with the stator base body 2 is prevented. Even if the conductor elements 8 are surrounded by an additional protective layer, the insulation effect can be further improved or additionally secured by the receiving device 7.As is further illustrated in FIG. 2, it is possible to provide a temperature control device through which temperature control medium can be guided through the receiving device 7. The receiving device 7 seals the stator grooves 3 in the radial direction, namely by the base section 9. tempering medium, which is introduced into the receiving device 7, for example on one axial side of the stator base body 2, flows through the receiving device 7 and thus flows around the conductor elements 8 within the receiving device 7. As is shown in FIG. 2, the receiving direction 7 extends beyond the stator grooves 3 in the axial direction, so that a sealing effect with respect to a rotor space is achieved. In the region of the axial ends of the receiving device 7, sealing elements can additionally be provided.FIGS. 5, 6 show an electric machine 1 according to a second exemplary embodiment. In principle, the same reference numerals are used for the same components. The exemplary embodiment shown differs from the exemplary embodiment shown with reference to FIGS. 1, 2 with regard to the course of the temperature control channels 13. In the exemplary embodiment shown, temperature control channels 13 running through the stator base body 2 in the axial direction are shown, in particular one temperature control channel 13 per stator groove 3, each of which has an outlet 14 in the region of the end wall 4. As a result, it is possible to introduce temperature control medium from each outlet 14 directly into the associated stator groove 3, namely directly into the receiving device 7 arranged there. As is illustrated in FIG. 5, the outlet 14 is located within the fastening receptacle 11. temperature control medium introduced into the stator groove 3 thus flows directly into the opening of the receiving device 7 which is situated opposite the base section 9. The temperature control medium is thus distributed within the receiving device 7, as is illustrated in FIG. 6, and can flow through the receiving device 7 in the axial direction.The embodiment shown increases the sealing effect when introducing the temperature control medium into the receiving direction 7, since the internal pressure within the receiving device 7 presses the wall sections 10 against the groove walls 6 and the fastening means 12, for example the latching hooks or the snap hooks, against the inner wall of the fastening receptacle 11.The advantages, details and features described in the individual exemplary embodiments with reference to the various figures can be combined with one another as desired, interchanged with one another and transferred to one another. The electric machine 1 shown can be produced in particular as described by the method described herein.Reference numerals denote reference numerals1 Electric machine 2 Stator base body 3 Stator groove 4 End wall 5 Groove opening 6 Groove wall 7 Receiving device 8 Conductor element 9 Base portion 10 Wall portion 11 Fastening receptacle 12 Fastening means 13 Temperature control channel 14 Outlet

Claims

Electric machine (1) comprising a stator base body (2) which has a plurality of stator slots (3) distributed in the circumferential direction and running in the axial direction, which slots extend in the radial direction along slot walls (6) between a radially outer end wall (4) and a slot opening (5), wherein the electric machine (1) has conductor elements (8), in particular in the form of a wave winding, which are arranged in the stator slots (3), characterized in that the conductor elements (8) of at least one stator slot (3) are arranged in a receiving device (7) which surrounds the conductor elements (8) and is arranged in the stator slot (3) and is fastened in the stator slot (3) in the region of the end wall (4).Electric machine (1) according to Claim 1, characterized in that the receiving device (7) has at least one fastening means (11) which is received, in particular in a positively locking manner, in a fastening receptacle (12) provided in the end wall (4).Electric machine (1) according to Claim 1 or 2, characterized in that the receiving device (7) is open in the direction of the end wall (4), in particular rectangular or U-shaped in cross section.Electric machine (1) according to Claim 1 or 2, characterized in that the receiving device (7) has latching hooks or snap hooks which are designed as fastening means (11).Electric machine (1) according to one of the preceding claims, characterized bya temperature control device which has at least one temperature control channel (13) running in the stator base body (2), wherein an outlet (14) of at least one temperature control channel (13) is arranged on or in the end wall (4) of the stator groove (3) and connects the interior of the receiving device (7) to the temperature control channel (13).Electric machine (1) according to Claim 5, characterized in that the outlet (14) of the temperature control duct (13) is arranged in the region of the fastening receptacle (12), wherein temperature control medium within the receptacle device (7) moves the at least one fastening means (11) of the receptacle device (7) against the fastening receptacle (12).Electric machine (1) according to one of the preceding claims, characterized in that the at least one receiving device (7) projects beyond the stator groove (3) in the axial direction.Electric machine (1) according to one of the preceding claims, characterized in that the at least one receiving device (7) is designed to electrically isolate the conductor elements (8) from the stator base body (2).Motor vehicle comprising an electric machine (1) according to one of the preceding claims.Method for producing an assembly for an electric machine (1), comprising a stator base body (2) which has a plurality of stator slots (3) distributed in the circumferential direction and running in the axial direction, which extend in the radial direction along slot walls (6) between a radially outer terminating wall (4) and a slot opening (5), wherein conductor elements (8), in particular in the form of a wave winding, are surrounded by at least one receiving device (7) and are introduced into the stator slots (3), characterized in that the conductor elements (8) of at least one stator slot (3) are surrounded by the at least one receiving device (7) and the at least one receiving device (7) is fastened with the surrounded conductor elements (8) in the region of the terminating wall (4) in the stator slot (3).

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