Magnetic field-generating part of an electric machine, such as a stator and / or a rotor, with improved winding head end plate, as well as electric machine and vehicle with it

Abstract

A magnetic field-generating part (6, 10) of an electric machine (1), such as a stator (6) or a rotor (10), is disclosed. It comprises a laminated core (7, 12), a winding head end plate (16, 16a, 16b), and wire windings (9, 14). The winding head end plate (16, 16a, 16b) has a star shape with a central opening (E) and radially extending arms (17), each having lateral boundary surfaces (G1, G2). Outer circumferential side walls (18) are provided on the arms (17), projecting from an end face (C1, C2) of the laminated core (7, 12). Axially below the wire windings (9, 14) the winding head end plate (16, 16a, 16b) has free spaces (J) adjacent to the lamella package (7, 12), each of which is spaced apart from an outer circumference of the winding head end plate (16, 16a, 16b) and leads continuously from a first lateral boundary surface (G1) to a second lateral boundary surface (G2) of a corresponding arm (17).Furthermore, an electric machine (1) with such a stator (6) and / or rotor (10) and a vehicle (20) with such an electric machine (1) are disclosed.

Description

TECHNICAL AREA

[0001] The invention relates to a magnetic field-generating part of an electric machine, such as a stator and / or a rotor. It comprises a lamination stack, a winding head end plate, and wire windings. The lamination stack comprises several axially stacked laminations with winding slots provided therein, wherein the lamination stack has a first end face and a second end face axially opposite the first end face. The winding head end plate is arranged on the lamination stack at the first end face. Viewed from the front, perpendicular to the first end face, it has a star shape with a central opening and radially extending arms, each of which has a first and a second lateral boundary surface located away from it. Furthermore, the winding head has outer circumferential side walls on the arms that project from the first end face.The wire windings are arranged in the winding slots of the laminated core and wound radially around the arms of the winding head end plate within the outer circumferential side walls. The invention further relates to an electric machine with such a stator and / or rotor, and to a vehicle with such an electric machine, wherein the electric machine is intended for propelling the vehicle. Finally, the invention relates to a method for manufacturing a magnetic field-generating part of an electric machine as defined above. STATE OF THE ART

[0002] A magnetic field-generating component, an electric machine, a vehicle, and a method of the above type are each generally known. Winding head end plates typically serve to guide the wire winding during the manufacture of the electric machine. Furthermore, they are used for the axial fixation of the rotor laminations and to prevent axial separation of the rotor laminations during rotor manufacturing and during operation of the electric machine. During the winding process, a tensile force is applied to the wire windings, which naturally causes elastic deformation of the wire windings and, in turn, an inward force acting with respect to the windings. Since the winding wire usually has a circular cross-section and the wire windings have a number of layers, lateral force components are also generated between the winding wires of the different layers.These lateral forces act circumferentially in the winding slots and radially at the winding heads. The laminated core is inherently relatively stiff, so these lateral circumferential forces do not play a significant role in the manufacture of an electric machine. However, the situation is different at the winding head end plates. Since the wire windings extend far outwards in the radial direction, the outer circumferential side walls that restrain the wire windings are naturally relatively thin. For this reason, these lateral radial forces can bend the circumferential side walls outwards and widen the outer diameter of the winding head end plates, which can lead to problems in the manufacture and operation of the electric machine.To avoid this phenomenon, comparatively rigid materials can be used for the winding head end plates, but this is unfortunately relatively expensive and increases the overall cost of the electric machine. REVELATION OF THE INVENTION

[0003] Accordingly, one object of the invention is to provide an improved magnetic field-generating part of an electric machine, such as a stator and / or a rotor, an improved electric machine, an improved vehicle, and an improved method for manufacturing a magnetic field-generating part. In particular, a cost-effective solution for winding head end plates is to be proposed that avoids widening the outer diameter of the winding head end plates during the winding process.

[0004] The object of the invention is achieved by a magnetic field-generating part disclosed in the introductory paragraph, in which the winding head end plate has clearances axially below the wire windings next to the laminate pack. Viewed from the front, the clearances are spaced apart from the outer circumference of the winding head end plate and extend continuously from the first lateral boundary surface to the second lateral boundary surface of the respective arm.

[0005] In general, the aforementioned magnetic field-generating part a) be a stator for the electric machine, wherein the laminated core is a stator laminated core, the winding slots are stator slots and the wire windings are stator wire windings, or b) be a rotor for the electric machine, wherein the lamination stack is a rotor lamination stack, the winding slots are rotor slots and the wire windings are rotor wire windings.

[0006] Furthermore, the object of the invention is solved by an electric machine comprising a stator and a rotor rotatably arranged relative to the stator, wherein the stator is designed according to case a) and / or wherein the rotor is designed according to case b).

[0007] Furthermore, the object of the invention is solved by a vehicle, wherein the vehicle comprises an electric machine of the above type and wherein the electric machine is provided for propelling the vehicle.

[0008] Furthermore, the object of the invention is achieved by a method for manufacturing a magnetic field-generating part of an electrical machine according to the above definition, wherein the method comprises the following steps: - Providing the louver package, - Arranging the winding head end plate on the first end face and - Arranging the wire windings in the winding slots of the lamination pack and winding them radially around the arms of the winding head end plate within the outer circumferential side walls; whereby a tensile force in the wire windings leads to a partial reduction in the height of the clearances and to an inward tilting of the outer circumferential side walls and / or to a bending stress within the winding head end plate, which causes an inwardly directed force acting on the outer circumferential side walls.

[0009] By utilizing the available space and the tensile force naturally occurring during the winding process in the wire windings, this inward tilting of the outer circumferential side walls and / or this inward force acting on the outer circumferential side walls is achieved, which in turn also causes a radial inward compression of the wire windings. In this way, a widening of the outer diameter of the winding head end plates during the winding process is avoided cost-effectively, and in particular, the winding head end plate can be manufactured from a comparatively inexpensive plastic.

[0010] Since the clearances are generally spaced from the outer circumference of the winding head end plate, external support surfaces are provided. If, in an optional embodiment, the clearances are spaced from the central opening, additional internal support surfaces are also provided. In both cases, this inward tilting of the outer circumferential side walls and / or this inward force acting on the outer circumferential side walls is caused by the tensile force in the wire windings. It should be noted, however, that the internal support surfaces are not strictly necessary, and the outer circumferential side walls will tilt inwards even without them.

[0011] The arms, viewed tangentially perpendicular to the first lateral boundary surface of a corresponding arm, can each have an essentially h-shaped profile. This h-shaped profile is a product of the outer circumferential side wall and the outer support surface (which together form the left long leg of the "h"), the inner support surface (which forms the right short leg of the "h"), and the clearance (which forms the gap in the "h").

[0012] In yet another advantageous embodiment, the arms can each have inner circumferential side walls projecting from the first end face, wherein the wire windings are wound radially around the arms of the winding head end plate between the inner circumferential side walls and the outer circumferential side walls. In this way, the winding wire is also reliably guided on the radially inner side.

[0013] The arms, viewed tangentially perpendicular to the first lateral boundary surface of a corresponding arm, can each have an essentially H-shaped profile. This H-shaped profile is a product of the outer circumferential side wall and the outer support surface (which together form the left long leg of the "h"), the inner circumferential side wall and the inner support surface (which together form the right long leg of the "H"), and the clearance (which forms the lower gap in the "H").

[0014] It should be noted that the proposed technical features generally relate to a magnetic field-generating part comprising a laminated core, laminations, winding slots, and wire windings. As already mentioned, the magnetic field-generating part can be configured as a stator or a rotor. If the magnetic field-generating part is configured as a stator, the aforementioned disclosure relates to a stator laminated core, stator laminations, stator winding slots, and stator wire windings. Likewise, if the magnetic field-generating part is configured as a rotor, the aforementioned disclosure relates to a rotor laminated core, rotor laminations, rotor winding slots, and rotor wire windings. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] The invention will now be described in more detail with reference to certain embodiments; however, the invention is not limited to these. Fig. Figure 1 shows a half-section view of an exemplary electrical machine; Fig. Figure 2 shows a cross-sectional view of an exemplary winding head end plate; Fig. Figure 3 shows a front view of the winding head end plate of Fig. 2, Fig. Figure 4 shows a detailed view of the winding head end plate of Fig. 2 in the radially outer area and Fig. Figure 5 shows a schematic representation of an electric vehicle. DETAILED DESCRIPTION

[0016] Generally, identical or similar parts are identified by the same / similar designations and reference numerals. The features disclosed in the description apply to parts with the same / similar designations or reference numerals. Information regarding orientation and relative position refers to the corresponding figure.

[0017] Fig. Figure 1 shows a half-section view of an exemplary electric machine 1. The electric machine 1 comprises a stator housing 2, a first end shield 3, and a second end shield 4. The stator housing 2, the first end shield 3, and the second end shield 4 together form a machine housing 5. The design of the machine housing 5 is merely exemplary, and other designs are possible. For example, the stator housing 2 can form a cup-shaped housing section with one of the end shields 3 or 4.

[0018] Furthermore, the electric machine 1 comprises a stator 6, which is arranged in the stator housing 2, and a stator lamination pack 7 with several axially stacked stator laminations 8 in which winding slots (in Fig. 1 not visible) are provided. In addition, the stator 6 comprises stator wire windings 9 arranged in the winding slots of the stator lamination stack 7, of which in Fig. 1 only the stator winding heads are visible.

[0019] Furthermore, the electric machine 1 comprises a rotor 10 with a rotor shaft 11 and a rotor lamination stack 12 mounted on the rotor shaft 11. The rotor lamination stack 12 comprises several axially stacked rotor laminations 13, in which winding slots B are provided. Additionally, the rotor 10 has rotor wire windings 14 arranged in the rotor winding slots B of the rotor lamination stack 12.

[0020] Furthermore, the electric machine 1 includes a first (roller) bearing 15a in the first bearing shield 3 and a second (roller) bearing 15b in the second bearing shield 4 to support the rotor 10 rotatably about a rotor axis or stator axis RA.

[0021] The rotor 10 comprises a first winding head end plate 16a on a first end face C1 of the rotor lamella pack 12 and a second winding head end plate 16b on a second end face C2 axially opposite the first end face C1. Finally, it shows Fig. 1 a frontal viewing direction D, which is aligned perpendicular to the first end face C1.

[0022] The Fig. Figures 2 to 4 now show in detail a winding head end plate 16, which is an example of one or both of the winding head end plates 16a, 16b of Fig. It can be 1. Specifically, it shows Fig. 2 a cross-sectional view of the winding head end plate 16, Fig. Figure 3 shows a front view of the winding head end plate 16 and Fig. Figure 4 shows a detail of the winding head end plate 16 in the radially outer area. For example, the winding head end plate 16 can be made of plastic.

[0023] Viewed from the front, the winding head end plate 16 has a star shape with a central opening E and radially extending arms 17, each of which has a first and a distant second lateral boundary surface G1, G2. The winding head end plate 16 has outer circumferential side walls 18 projecting from the first end surface C1 on the arms 17, with the rotor wire windings 14 being wound radially around the arms 17 of the winding head end plate 16 within the outer circumferential side walls 18.

[0024] Axially below the rotor wire windings 14, the winding head end plate 16 has clearances J adjacent to the rotor lamella assembly 7, which, viewed from the front D, are each spaced apart from an outer circumference of the winding head end plate 16 and extend continuously from the first lateral boundary surface G1 to the second lateral boundary surface G2 of a corresponding arm 17. The clearances J can be spaced apart from the central opening E, which is the case in the example of the Fig. 2 to 4 is the case. Furthermore, the arms 17, each viewed in a tangential direction H perpendicular to the first lateral boundary surface G1 of a corresponding arm 17, can have an essentially h-shaped profile I, which in the example of the Fig. 2 to 4 is also the case.

[0025] The winding head end plate 16 can include optional inner circumferential side walls 19 that project from the first end face C1, as shown in the Fig. Figures 2 to 4, shown with dashed lines, depict the rotor wire windings 14 being wound radially around the arms 17 of the winding head end plate 17 between the inner circumferential side walls 19 and the outer circumferential side walls 18. The arms 17, viewed tangentially H perpendicular to the first lateral boundary surface G1 of a corresponding arm 17, can each have a substantially H-shaped profile I', which is shown in Fig. 2 is shown with dashed lines.

[0026] A method for manufacturing a rotor 10 of an electric machine 1 can comprise the following steps, with particular emphasis on Fig. 4. Reference is made to: - Provision of the rotor blade package 12, - Arranging the winding head end plate 16, 16a, 16b on the first end face C1 and - Arranging the rotor wire windings 14 in the winding slots B of the rotor lamella pack 12 and winding them around the arms 17 of the winding head end plate 16, 16a, 16b radially within the outer circumferential side walls 18.

[0027] Since the clearances J are generally spaced from the outer circumference of the winding head end plate 16, external support surfaces K are provided. If the clearances J are spaced from the central opening E, additional optional internal support surfaces L are provided, which is necessary for the Fig. 2 to 4 apply. In both cases, the tractive force F Tin the rotor wire windings 14 to a partial reduction of the height d of the free spaces J and to an inward tilting M of the outer circumferential side walls 18 and / or to a bending stress within the winding head end plate 16, 16a, 16b, which causes an inwardly directed force F acting on the outer circumferential side walls 18 IN This results in the following: It should be noted that the inner support surfaces L are not absolutely necessary and that the outer circumferential side walls 18 will tilt inwards even without an inner support surface L.

[0028] It should be noted that the square profile of the cross-section of Fig. The four free spaces shown are not strictly necessary and other forms are also possible. For example, it shows Fig. 4 In this context, schematically an alternative beveled or angled clearance profile N and a rounded clearance profile N'.

[0029] It should also be noted that although the proposed technical features were presented with reference to the rotor 10, the same technical teaching applies equally to the stator 6. Thus, in the disclosure above, the rotor 10 can be replaced by the stator 6, the rotor lamination stack 12 can be replaced by the stator lamination stack 7, the rotor lamination 13 can be replaced by the stator lamination 8, the rotor winding slots B can be replaced by stator winding slots, and the rotor wire winding 14 can be replaced by the stator wire winding 9. More generally, the stator 6 and the rotor 10 are magnetic field-generating parts and can be referred to as such. In this context, reference can also simply be made to a lamination stack 7, 12, a lamination 8, 13, a winding slot B, and a wire winding 9, 14.

[0030] The use of the free spaces J generally provides a radial inward compression of the wire windings 9, 14, which in turn avoids a widening of the outer diameter of the winding head end plates 16, 16a, 16b during the winding process.

[0031] Finally, it shows Fig. 5 an electric vehicle 20 with an electric machine 1 as defined above, which is intended for propelling the electric vehicle 20. In detail, the electric machine 1 is coupled to an optional transmission 21, side shafts 22 and finally to the wheels 23. The electric machine 1 can be designed to propel the electric vehicle 20 permanently in a fully electric vehicle or temporarily, e.g. in combination with an internal combustion engine, in a hybrid vehicle.

[0032] It should be noted that the invention is not limited to the embodiments disclosed herein, but that combinations of the different variants are possible. In practice, the electric machine 1 and the electric vehicle 20 may have more or fewer parts than shown in the figures.

[0033] It should also be noted that the electric machine 1 and the electric vehicle 20, or parts thereof, are not necessarily drawn to scale in the figures. Furthermore, the description may include subject matter of other independent inventions.

[0034] It should also be noted that the term "comprises" does not exclude other elements, and the use of the articles "a" does not preclude the plural form. Furthermore, elements described in connection with different embodiments may be combined. It should also be noted that reference numerals in the claims are not to be interpreted as limiting the scope of protection of the claims. Reference symbol list 1 electric machine 2 Stator housings 3 first warehouse sign 4 second warehouse sign 5 machine housings 6. Magnetic field-generating part (stator) 7 (stator) laminate pack 8 (stator) lamellae 9 (stator) wire winding 10. Magnetic field generating part (rotor) 11 Rotor shaft 12 (rotor) louver package 13 (rotor) blades 14 (rotor) wire winding 15a, 15b (roller) bearings 16, 16a, 16b Winding head end plate 17 Arm of the coiled head endplate 18 outer circumferential side wall 19 inner circumferential side wall 20 vehicles 21 gearboxes 22 Side shaft 23 wheel RA Rotor axis / Stator axis B Winding groove C1, C2 end face, rotor disk pack D frontal viewing direction E central opening of the winding head end plate F IN inward-directed force F T traction G1, G2 lateral boundary surface of the winding head end plate arm H tangential viewing direction I h-shaped profile I' H-shaped profile J Free space K outer support surface L inner support surface M Inward tilting / Inward tilting movement N beveled clearance profile N' rounded clearance profile d Height of the free space

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