Stator

Abstract

The stator comprises a stator core (1) with stator teeth (3), at least one first and one second end cap (7) each having a base (31) and a winding wire carrier (9), which end caps are arranged on the same stator tooth (3) such that the base (31) faces an end face of the stator tooth (3), and a stator winding with at least one winding wire (39), which end caps are arranged on the same stator tooth (3) such that the base (31) faces the end face of the stator tooth (3). And the winding wire is wound on the stator teeth (3) through the end part cover (7). The winding wire holder has two projections (33) which project opposite each other over the base, and the winding wire extends over the projections of the first and second end caps. According to the invention, an insulating film is provided, which comprises an end-side edge, extends between one of the projections of the first end cap and an opposite projection of the second end cap, and is arranged between the winding wire and the stator teeth, the winding wire extending over the projections without exerting a force effect on the end-side edge of the insulating film.

Description

Technical Field

[0001] The invention relates to a stator, in particular to a stator for an electric motor. Background Art

[0002] Electric motors can be used in vehicles, for example commercial vehicles. Vehicles can have a drive as an alternative to a fossil fuel internal combustion engine in order to reduce CO2 emissions. Such electric drives can be powered, for example, by fuel cells or batteries. One field of application of electric motors in vehicles is the cooling of drives, batteries or electronic devices. The electric motor drives a fan which cools the components. For such applications, compact dimensions, also in the axial direction, and high power are desirable.

[0003] The stator is part of an electrical machine, such as an electric motor. The stator is the fixed part of the electric motor, in which the rotor, which is the rotating part of the electric motor, rotates. The stator has a stator winding, through which a time-varying magnetic field is induced by means of a time-varying current, which causes the rotor to rotate.

[0004] The stator comprises a stator core with a plurality of stator teeth, on the opposite end sides of which end caps are arranged. The stator winding comprises winding wires which extend in a coil shape around the stator teeth and their end caps. The end caps hold and guide the stator winding. Conventional stators are wound manually. The windings and their wire guidance between the coils are manufactured by manual methods. The insulation between the stator components is achieved using Kapton tape, insulating paper or flame-retardant composite materials, which are classified as FR4, for example. These components are cast. Undesirable bubbles in the casting may lead to overheating, which adversely affects the thermal properties.

[0005] US8736129B2 shows an end cap of a stator segment, which is arranged to position the wire in a desired position in a segmented stator assembly. The end cap includes a body and an inner wall. A terminal recess is provided in the body for accommodating the wire and for establishing the desired electrical connection. A step located in the terminal recess helps to secure the connector in the terminal recess. There is a platform on the outside of the clip recess and a recess defined in the platform to trim the wire accommodated in the clip recess as required. There is a retaining structure around the end cap, which helps to place the wire in the desired position.

[0006] End covers for a segmented stator are also shown in US D539219 S.

[0007] US8278803B2 shows an electric motor provided with a set of end cap guides at the end of the stator winding assembly for controlling the end caps to the correct position relative to the stator winding assembly so that the rotor assembly is held concentrically with the stator. The end cap guides may be rings fitted into the winding insulator at the end of the stator laminations, or may be integrated into the winding insulator as guide segments to form a discontinuous cylindrical inner surface consistent with the inner diameter of the stator winding assembly. The guides allow the rotor assembly to be correctly positioned without increasing the length of the stator laminations. Summary of the invention

[0008] The object of the present invention is to provide an alternative stator in which the risk of overheating is reduced.

[0009] This object is achieved by a stator having the features of claim 1. The stator is provided with a stator core and at least one first end cap and at least one second end cap, the stator core comprising a plurality of stator teeth, the stator teeth each having a first end side and a second end side, the first end cap and the second end cap each comprising a base and a winding wire support, wherein the first end cap is arranged on the first end side of one of the stator teeth and the second end cap is arranged on the second end side of the same stator tooth, so that the base of the end cap faces the end side. The stator winding has at least one winding wire, which is wound around the stator tooth via the first end cap and the second end cap. The winding wire support has two projections, which protrude from the base on opposite sides, wherein the winding wire extends over the projections of the first and second end caps. An insulating film is provided, which has an edge at the end side and extends between one of the projections of the first end cap and the opposite projection of the second end cap and is arranged between the winding wire and the stator tooth, wherein the winding wire extends over the projection without exerting forces on the edge at the end side of the insulating film.

[0010] The stator is provided for an electrical machine, in particular an electric motor. The stator is the stationary part of an electrical machine, in particular an electric motor. Inside the stator is a cavity, in which the rotatable rotor of the electrical machine is arranged. The above-described system is advantageously cast, so that the stator winding is embedded in the hardened casting material.

[0011] The stator core has a cavity for the rotor and a plurality of stator teeth, which extend radially and on which the stator winding is arranged. The axial direction corresponds to the longitudinal axis extending through the cavity, which is also the axis of rotation of the rotor. The end side is in a plane perpendicular to the axial direction. The cavity is surrounded by an annular region of the stator core. The stator teeth advantageously extend outward. In one embodiment, the stator teeth each have a widened end region so that the stator winding is supported radially outward. The inward radial support is achieved by the annular region. The stator core advantageously comprises iron and is constructed as a laminated core consisting of stacked laminations.

[0012] The stator winding comprises at least one winding wire to form one or more poles on a stator tooth. The winding wire advantageously comprises copper and / or aluminum. In one embodiment, the stator winding is configured as a single winding, whereby a coil having a plurality of windings is wound around exactly one stator tooth. Such a single winding is also referred to as a concentrated winding. However, a pole may comprise a plurality of coils on a plurality of adjacent stator teeth. The opposite of a single winding is a distributed winding, in which a coil extends over a plurality of stator teeth.

[0013] These end caps are arranged on the end sides of the stator teeth. By winding the winding wire multiple times on the end caps and the stator teeth, the winding wire forms a coil around one of the stator teeth. The coil extends axially along the longitudinal side of the stator core. The axially extending longitudinal sides of two adjacent stator teeth face each other. The longitudinal sides of a stator tooth are opposite. The top view profile of the longitudinal side can be pot-shaped. The coil has multiple layers of winding wire, wherein the first layer contacts the end cap. The winding wire section on the edge also contacts the end cap.

[0014] The end caps are advantageously made of an insulating material, for example plastic. In one embodiment, the end caps are designed as injection molded parts. An alternative is to 3D print the end caps. The bottom profile of the end caps advantageously corresponds at least approximately to the top profile of the stator teeth, so that the end caps are placed flush or almost flush on the stator teeth in the region of the longitudinal sides. The connection between the end caps and the stator teeth can be, for example, an adhesive connection. However, adhesive bonding and clamping of the end caps also allow for rapid production.

[0015] The winding wire support of the end cover is a region which holds and supports the winding wire of the coil on the end cover, wherein the support is realized axially and radially. The winding wire support advantageously has a pot-shaped or rectangular profile, the bottom of which is a support and axial support for the first layer of the coil and the sides of which radially support the coil. Advantageously, the winding wire support has radially spaced apart outer and inner winding space limitation parts. The mutually facing sides of the outer and inner winding space limitation parts can be inclined so that the coil widens with increasing distance from the stator teeth. In one embodiment, the outer winding space limitation part has walls protruding axially from the base, between which there is a gap. The inner winding space limitation part comprises two hollow pillars, which have the basic shape of a hollow cylinder.

[0016] The recess in the support can be used to fix thereto another component arranged on the end side, which engages into the recess with a projection in order to form a connection with the support. These end caps thus provide a mounting and positioning possibility for a module, which can be placed on the end side of the end cap of the stator. Such a module can be provided for wiring and / or connecting and / or supplying a stator winding. For example, wire routing between poles spaced apart from one another and / or wiring between the poles and / or system supply can be achieved by means of the module, which is achieved, for example, by means of a lead frame in the module.

[0017] The base of the end caps separates the winding wire support from the end side of the stator core. The winding wire extends axially along the opposite longitudinal sides of the base. The projections on the opposite sides of the winding wire support protrude beyond the base, so that the base is defined by the protruding lower edge of the projection on the side facing away from the end side of the stator core. Advantageously, the projections extend transversely to the axial direction. In the winding area, the winding wire is guided along the base, and the projections advantageously extend on the base along the edge of the end side of the insulating film in the entire winding area. The winding wire extends axially between the opposite projections of the first and second end caps and is separated from the base and the longitudinal sides of the stator teeth by these projections.

[0018] In one embodiment, the end caps are each configured mirror-symmetrically with respect to the radial direction. The first and second end caps on the opposite end sides of the stator core are advantageously configured identically and arranged mirror-symmetrically with respect to one another. In one embodiment, the end caps are configured as a one-piece end disk on the first or second end side. Such an end disk comprises all the end caps of one end side and is advantageously configured as a one-piece plastic part. Alternatively, a plurality of but not all end caps are configured as one-piece end disk segments at the same end side, so that the end disk comprises a plurality of, for example three, arc-shaped end disk segments.

[0019] The insulating film is a film made of a non-conductive material. For this reason, the name "insulating paper" is also often used, but it does not necessarily have to be paper. The insulating film is arranged between the winding wire and one of the axially extending longitudinal sides of the stator tooth and the base at the end side in order to insulate the metal parts and protect them from partial discharges. The insulating film brings about axial insulation of the stator core. The insulating film is also arranged in the same way on the opposite longitudinal side of the stator tooth.

[0020] The projections prevent forces from being applied to the edges of the end sides of the insulating film. Applying force means applying a force in the axial direction to the edges of the insulating film that face the projections and are axially opposite to each other. The axial direction extends between the end sides. The insulating film extends between the opposite balcony-like projections of the first and second end caps, so that the winding wire extending on the projections does not cause forces extending in the axial direction to be applied to the edges of the end sides of the insulating film that face the projections. When applying the winding or by the applied stator winding itself, the edges of the end sides are not subjected to the application of axial forces that could deform the insulating film. As a result, the insulating film lies flat between the end caps and the longitudinal sides of the stator and the winding wires.

[0021] Deformations of the insulating film are undesirable, since such deformations can have an adverse effect on the thermal properties of the stator. By means of deformations of the insulating film, in particular flattening or bulging in the insulating film, air can be trapped which can no longer escape during casting, so that gas bubbles are generated between the insulating film and the stator core. Since the stator core also serves to dissipate heat from the stator coils, a good thermal coupling between the stator coils and the stator core is important to prevent overheating. However, if gas bubbles are present, due to the thermal insulation effect of the gas bubbles, they will worsen the thermal coupling between the stator coils and the stator core and will hinder the dissipation of heat.

[0022] In order to avoid axial loads or deformations caused by the protrusions themselves, the length of the insulating film is advantageously slightly smaller than the spacing of the protrusions. The insulating film is loosely supported on the stator core so that it can move in the axial direction before the stator winding is applied. The protrusions (between which the insulating film extends) each have a stop, which is configured as a protruding edge of the protrusion to prevent the axial movement of the insulating film. The stop is configured in such a way that axial forces on the edges of the end sides of the insulating film are avoided. Such forces may deform the insulating film and have the above-mentioned consequences. Advantageously, the stop has a width corresponding to the thickness of the insulating film, so that forces are reliably prevented from being applied axially to the edges of the end sides of the insulating film, and the winding wire and the stator core are arranged as close to each other as possible in the region of the longitudinal side of the stator core due to good thermal coupling; there is only the insulating film between them. By arranging the stator coil as close as possible to the stator core, it is possible to achieve excellent heat transfer to the stator core, in particular a water-cooled stator core, and thus improve the thermal performance compared to conventional stators, and thus improve the overall performance of the stator.

[0023] When the insulation is matched, the insulating film enables matching of the necessary leakage resistance from the coil to the stator core so as not to exceed the predetermined creepage strength. The insulating film extends beyond the stator core so that the insulating film overlaps the base of the first end cover and the second end cover. In this overlapping area, the insulating film extends between the winding wire and the base. The overlapping length of the portion of the insulating film that overlaps the base contributes to the creepage distance between the metal (especially copper) coil and the metal (especially iron) stator core. The overlapping length is equivalent to the required creepage distance plus a safety buffer zone between the winding wire and the stator core. Due to this construction, there is no need for an end cover flange located above the stator core as in a conventional stator, and the end cover and the stator core do not overlap. The stator with the above-mentioned insulating film has not only good thermal characteristics, but also good insulation for improved performance.

[0024] The size of the stator can be large or small, taking into account factors such as the necessary inner diameter of the stator core, the maximum predetermined length, and the desire for a stator system that is as compact as possible. The short axial length makes the stator design possible, which complements the compact stator unit.

[0025] In one embodiment, the insulating film is a first insulating film extending along a first longitudinal side of the stator tooth. A second insulating film extends along a second longitudinal side of the stator tooth opposite to the first longitudinal side between another protrusion of the first end cap and an opposite protrusion of the second end cap and is arranged between the winding wire and the stator tooth and between the winding wire and the base. The insulating films on the longitudinal sides of the stator teeth also extend along adjacent longitudinal sides of adjacent stator teeth. Such an insulating film extending between two adjacent stator teeth can be pre-bent according to the top view contour of the stator teeth so that it can be clamped into its position between the stator teeth in a simple manner and held by the stator teeth in a force-locking manner.

[0026] All stator teeth of the stator core with their end covers and the insulating films on both longitudinal sides are designed in the same way as described above.

[0027] The stator can be manufactured by machine. The stator winding is advantageously applied by needle winding. In needle winding, a nozzle-like needle, which guides the winding wire to the stator core, is moved horizontally and vertically along the stator core. In this process, the needle runs around the stator core and winds it on the longitudinal side. With the stator teeth protruding outwards, the needle can apply the winding of the coil in a simple manner by guiding the needle between the gaps between adjacent stator teeth. This method of producing a machine-wound stator saves time and money.

[0028] During the winding process, the wire guidance between the coils of adjacent stator teeth is supported by two struts of the inner winding wire restriction in that the winding wire between two adjacent coils is guided through the two struts and is guided on the inside along the struts. The struts thus serve not only for radial support of the coils but also for guiding the winding wire at the transition to the adjacent stator teeth.

[0029] The winding wire support is advantageously designed in such a way that it serves as a supporting structure for forming an orthogonal loop winding. The wires form a dense packing, wherein the upper wire layer lies in the groove of the lower layer. In order to support this winding, the winding wire support has a 60° bevel and a corresponding guide groove. The 60° bevel is integrated into the winding space limitation, whose sides facing each other have such a bevel. This design ensures static stability during the needle winding process by absorbing the loads that occur through the bevel and introducing the forces into the base and the bottom area of ​​the winding wire support. The winding space limitation with the pillars is integrated into the cover structure in order to provide structural rigidity for the forces that occur during machine winding. In addition, the pillars also provide the possibility of docking for another component, as described above.

[0030] The guide grooves in the radial and axial directions, in particular the guide grooves at the rounded projections, support the correct, predetermined positioning of the first winding layer, which is placed directly on the bottom between the winding space limits of the winding wire support. As a result, the first winding layer also provides a secure support with a predetermined position for all winding layers above it. The contour of the guide grooves is advantageously formed as a polynomial shape consisting of spline curves. Compared to a circular arc shape, the axial space requirement of the winding wire is reduced and, despite this, convex deformations of the winding wire from the radial direction (the so-called "belly effect") are minimized when winding pre-bent winding wires. In addition to the term "belly effect", the name "barrel effect" is also used.

[0031] In the next manufacturing step, the stator is cast. The flow channels in the end caps provide space for the still liquid casting material below the coils. This results in better flow properties of the casting material and fewer bubbles in the hardened casting material, which results in better thermal properties.

[0032] Advantageously, ventilation holes are provided in the end cap. The ventilation holes extend from the cavity on the bottom side of the end cap, in particular axially through the winding wire support and / or radially through the end face of the end cap. In one embodiment, the ventilation holes are arranged in the flow channel. The ventilation holes prevent air from accumulating under the end cap and facilitate the flow of the casting material during casting.

[0033] Overall, the stator combines good insulation coordination, machine windability and a small axial length in a castable system. The stable fit of the insulating film in the stator keeps axial loads away from the end edges of the insulating film, thus preventing deformation of the insulating film and the formation of bubbles during casting. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] Several embodiments are described in detail below with reference to the accompanying drawings.

[0035] Figure 1 shows a three-dimensional view of an embodiment of a stator,

[0036] Figure 2 is a top view of an embodiment of an end plate,

[0037] Figure 3 is a three-dimensional side view of one embodiment of an end cap on a stator tooth,

[0038] Figure 4 3D view of the end caps with insulating film on the stator teeth, viewed obliquely from above.

[0039] Figure 5 shows a partial perspective view of an embodiment of a stator having a plurality of stator teeth and end caps,

[0040] Figure 6 A three-dimensional view showing a section of the stator winding on the stator teeth and end caps,

[0041] Figure 7 This is a three-dimensional view of a part of the end plate.

[0042] Figure 8 A three-dimensional view of a detail of another embodiment of an end plate, seen from above, and

[0043] Fig. 9 Show Figure 8 3D view of a detail of the end plate in FIG. 1 from below. DETAILED DESCRIPTION

[0044] In the figures, identical or functionally identical components are provided with the same reference symbols.

[0045] Figure 1An embodiment of a stator is shown in a three-dimensional illustration. The stator comprises a stator core 1 with a laminated core. Stator teeth 3 are formed in the stator core 1 and extend outward in a circumferential manner. End disks 5 are arranged on two opposite end sides of the stator core 1, the bottom contour of which corresponds at least substantially to the top contour of the stator core 1. The end disks 5 are glued on. The end disks 5 comprise end caps 7 on the end sides of the stator teeth 3. The end disks 5 can be designed as one piece (as in the embodiment) or as multiple pieces. These end caps 7 have a winding wire support 9 with internal and external winding space limiters 11 for the stator winding 13. Each of the two end disks 5 is oriented on the stator core 1 in a predetermined manner by means of the positioning pins of the end disks 5 which engage in the grooves 53 in the stator core 1. The positioning pins and the grooves 53 are associated with simple production.

[0046] The stator winding 13 extending on the stator teeth 3 and their end covers 7 extends in the winding wire support 9, and the stator winding has a plurality of winding wires 39, which are held by the winding wire support 9 and radially supported by its winding space limiter 11. The stator winding 13 includes a plurality of individual windings, wherein each winding wire 39 is coiled around an adjacent stator tooth 3 to form a pole. The stator in this embodiment has six poles, each of which includes three stator teeth 3. For illustration purposes only, the winding wires 39 on the three stator teeth 3 arranged on the left side of the front are not shown. The stator winding 13 is powered by a three-phase current having three phases. For the sake of clarity, the power supply interface is not shown.

[0047] When manufacturing such a stator, the stator winding 13 is formed by needle winding. In needle winding, a needle that guides the winding wire 39 to the stator core 1 moves around each stator tooth 3 of one pole. Here, the needle runs around the stator core 3 and winds the stator core.

[0048] A wire guide module 15 having a recess 17 for a winding wire 39 extending between the poles is placed on one of the end disks 5 and forms a positive or non-positive connection 21 with the end disk 5. For example, the wire guide module 15 is clamped, clamped or glued. In this exemplary embodiment, the inner winding space delimiter 11 is designed as a pair of hollow struts 19. Two projections of a corresponding connecting element 55 of the wire guide module 15 engage in the recesses 47 of two adjacent struts 19 serving as connecting elements in order to form the connection.

[0049] The winding wire 39 is guided between the spaced-apart poles for the same phase through the wire guide module 15. Furthermore, the wiring is carried out on the wire guide module 15, for example in the manner of a star connection. However, for the sake of clarity, the winding wire on the wire guide module 15 is not shown.

[0050] The above-mentioned stator is also cast in order to achieve a permanent connection between the wire guide module 15 and the end disk 5 and to protect the components, in particular the stator winding 13 .

[0051] Figure 2 The top view of an embodiment of an end disk 5 is shown as it is placed on both end sides of the stator core 1. The end disk 5 has an annular inner region 23, from which radial T-shaped regions 25 extend outwards. The T-shaped region 25 has widened end regions.

[0052] The end disk 5 is designed in one piece and comprises a plurality of end caps 7, in the exemplary embodiment eighteen end caps, which are attached to the stator teeth 3. Each end cap 7 comprises an arcuate section of the end disk 5 having an outwardly projecting T-shaped region 25.

[0053] On the upper side of each end cap 7, a winding wire support 9 for the stator winding 13 is arranged. The winding wire support 9 is delimited radially by an outer and an inner winding space limitation 11, between which the winding wire 39 of the stator winding 13 extends. The winding space limitation 11 supports the winding wire in the radial direction on the annular inner region 23 and the widened end region. Between the winding space limitation 11 is the bottom 29 of the winding wire support 9, which supports the coil axially. The side edges of the bottom 29 extend substantially parallel to the radial direction. The outer winding space limitation 11 comprises walls 27 protruding axially from the winding wire support, between which there is a gap. The inner winding space limitation 11 comprises two hollow pillars 19 with a cylindrical basic shape. A flow channel 49 for the casting material extends in the radial direction between the gap and the pillars 19 as a recess in the winding wire support 9.

[0054] The winding wire support 9 is formed protrudingly on a base 31 below the winding wire support 9 (at Figure 2 The opposite projection 33 above the base 31 has a guide groove 35 in the bottom region, in which the winding wire 39 extends substantially transversely to the radial direction on the bottom 29. The guide groove 35 predetermines the placement of the winding wire section for the first layer directly on the winding wire support 9. The further layers are arranged above.

[0055] Figure 3 A side view of an embodiment of an end cap 7 on a stator tooth 3 is shown in three dimensions. Figure 3 Only one of the end covers 7 and a part of the stator teeth 3 are shown.

[0056] The end cap 7 has a base 31 which faces the end side of the stator tooth 3. The base 31 extends below the winding wire support 9 and spaces it apart from the stator core 1. The base 31 extends flush or almost flush with a longitudinal side 37 of the stator, and the winding wire 39 (at Figure 3 The stator core 1 is provided with a plurality of projections 33 (not shown in the figure). The end caps 7 do not overlap the stator core 1. The longitudinal sides 37 of the stator teeth 3 have a pot-shaped top view profile, which radially supports the coils formed by the winding wires 39. On the upper side of the base 31 is an edge 41, which protrudes not only from the base 31 but also from the longitudinal sides 37 of the stator core 1. This edge 41 is the lower side of the projection 33 facing the base 31. The projection 33 has a guide groove 35 for the winding wire 39, which results in a wavy top view profile of the bottom edge.

[0057] The wall 27 and the support 19 as the inner or outer winding space limiter 11 are configured as ramp-shaped slopes 43 on the sides facing each other and thereby form an inclined support and radial support for the stator winding 13. The ramp-shaped side surface is a 60° slope to radially support and support the orthogonal loop winding.

[0058] On the other end side of the stator tooth 3, the opposite Figure 3 The end caps 7 not shown in the figure are designed identically and are arranged in a mirror-image manner. The other stator teeth 3 and their end caps 7 are designed in the same way.

[0059] Figure 4 The three-dimensional illustration shows a view of the end cap 7 on the stator tooth 3 and the insulating film 45 on the longitudinal side 37 of the stator tooth 3 from obliquely above. Instead of the insulating film 45, the name "insulating paper" is also commonly used. Figure 4 Only one of the end caps 7 and a part of the stator teeth 3 are shown.

[0060] The insulating film 45 extends between the opposite projections 33 of the end cap 7 on the opposite end side of the stator tooth 3 on the longitudinal side 37 of the stator tooth 3 which is located at the front in the view. The insulating film 45 is longer than the axial height of the stator tooth 3 so that its upper and lower sections overlap with the base 31 of the end cap 7. Advantageously, the insulating film 45 extends up to the edge 41 of the projection 33. However, the insulating film 45 is not crushed by the edge 41. On the contrary, the insulating film 45 has a gap in the axial direction, which is limited by the edge 41 which serves as a stop. In order to prevent the insulating film 45 from being crushed, a buffer is provided as a difference between the distance and the length between its length and the distance between the opposite projections 33 of the opposite end cap 7. Advantageously, the thickness of the insulating film 45 is the same as the width of the edge 41 or slightly smaller than the width of the edge 41. However, the area of ​​the projection 33 which defines the guide groove 35 can extend beyond the insulating film 45, and the winding wire 39 (at Figure 4 (not shown) extends between these regions.

[0061] A further insulating film 45 is arranged in the same manner on the opposite longitudinal side 37 of the stator tooth 3. It extends up to the adjacent longitudinal side 37 of the adjacent stator tooth 3 and, as described above, on its adjacent longitudinal side 37 between the end caps 7.

[0062] The insulating film 45 forms an insulating layer between the metal winding wire 39 wound around the stator tooth 3 and the metal stator tooth 3 .

[0063] Figure 5 A detail of a stator with a plurality of stator teeth 3 and end caps 7 is shown in a three-dimensional illustration. For a better understanding, the stator winding 13 is shown only on three of the stator teeth 3, which correspond to one pole. The end caps 7 are glued to the upper and lower end sides of the stator teeth 3.

[0064] In the absence of stator teeth 3 and end caps 7 of the stator winding 13, the course of the insulating film 45 can be seen, which extends between the longitudinal sides 37 of two adjacent stator teeth 3 and forms an insulating layer in the axial direction along the stator teeth 3. Only in the gaps between the end regions of the stator teeth 3 is the insulating film 45 not provided so that the needle can be guided between the stator teeth 3 during needle winding in order to wind the winding wire 39 around the stator teeth 3 and the end caps 7.

[0065] The winding wire 39 of the stator winding 13 is wound around the stator tooth 3 as a coil and extends on the end cover 7. In this case, the winding wire 39 extends substantially transversely to the radial direction on the winding wire support 9 of the end cover 7. The winding wire 39 extends between opposite projections 33 of the end cover 7 on the same stator tooth 3 along the base side and the longitudinal side 37 of the stator tooth 3, wherein the winding wire 39 is guided by the projections 33 of the winding wire support 9 on the end edges of the insulating film 45 without the insulating film 45 being flattened in the axial direction. As a result, the insulating film 45 lies flat and free of bubbles on the base side and the longitudinal side 37 of the stator tooth 3.

[0066] The winding wire 39 wound around the stator teeth 3 is supported radially by the axially protruding winding space limitation 11 and the cup-shaped longitudinal sides 37 of the stator teeth 3. The winding wire between adjacent stator teeth 3 is guided through the annular inner region 23 of the end disk 5. Here, the winding wire 39 is guided inwards between the struts 19 of one of the end caps 7, then extends on the inside along the struts 19 and then between the struts 19 of the adjacent end caps 7 to its winding wire support 9.

[0067] Figure 6 A detail of the stator winding 13 onto the stator tooth 3 and the end cap 7 is shown in detail in a three-dimensional view. An insulating film 45 extends between the winding wire 39 and the stator tooth 3 and the base 31 .

[0068] Due to the protrusion 33, no axial force (neither through the winding wire 39 nor through the application of the winding wire during needle winding) acts on the insulating film 45. This prevents the insulating film 45 from bending toward the gap between adjacent stator teeth 3 and prevents air that may not leak out during casting from being enclosed. If the insulating film 45 is flattened due to the axial force, bubbles may be generated between the insulating film 45 and the stator core 1 during the casting, resulting in poor thermal performance of the stator. Since the width of the edge 41 corresponds to the thickness of the insulating film 45, the winding wire 39 is as close to the stator core 1 as possible despite the presence of the insulating film 45 between the winding wire 39 and the stator core 1.

[0069] The base 31 of the end cap 7 overlaps the insulating film 45. The axial length of the overlapping area corresponds to a predetermined creepage distance, wherein a safety buffer is located between the iron of the stator core 1 and the copper of the winding wire 39, thereby avoiding discharges.

[0070] During the subsequent casting of the stator, the stator winding 13 is embedded in the casting material. Through the flow channels 49 in the end caps 7, the casting material can flow under the winding wires 39 on the winding wire support 9 and the air can escape. The casting body formed by the hardened casting material has a substantially hollow cylindrical shape, in which the stator winding 13 extends on the stator teeth 3. In order to avoid air inclusions, in the cast state, as described above, the insulating film 45 also extends flat and is not deformed between the stator winding 13 and the stator teeth 3 and the base 31.

[0071] Figure 7 A three-dimensional illustration shows a detailed section of an end plate 5 with a plurality of end caps 7. The above-described features of the end caps 7 can be clearly seen in this figure.

[0072] The base 31 brings about an axial spacing of the winding wire support 9 from the stator core 1. The base length and, in particular, the insulating film 45 overlapping the base 31 (in Figure 7 The desired creepage distance is achieved by combining the two (not shown).

[0073] The winding wire support 9 extends laterally on the base 31 and forms a balcony-like projection 33 which has an edge 41 as a stop for an insulating film 45 .

[0074] The outer winding space limitation 11 comprises a wall 27 which protrudes axially from the winding wire support 9, between which there is a gap. The inner winding space limitation 11 has two hollow struts 19. The winding space limitation 11 has 60° bevels 43 facing each other in order not only to support the coil radially but also to achieve an orthogonal winding. The guide grooves 35 in the radial and axial direction of the winding wire support 9 support the correct positioning of the first winding layer. The struts 19 additionally serve as winding wire guides and for the assembly and positioning of modules, which can be placed on the end side of the stator.

[0075] The flow channel 49 extends in the radial direction over the entire upper side of the end cap 7. The flow channel extends between the winding space restrictions 11 and provides space below the coil, whereby the casting material can flow well and avoid bubbles. In this embodiment, the flow channel 49 has a triangular cross section.

[0076] Figure 8 A three-dimensional top view shows a detailed section of a further exemplary embodiment of an end plate 5 with a plurality of end caps 7. The following description focuses on the differences from the above-described embodiment.

[0077] The top view contour of the winding wire support 9 increases with increasing radius, so that it has a trapezoidal basic shape. This facilitates the winding of the needle. The winding wire support 9 extends laterally on the base 31 and forms a balcony-like projection 33, which has an edge 41 as a stop for the insulating film 45. A plurality of guide grooves 35 are provided in the edge region of the winding wire support 9.

[0078] The flow channel 49 extends in the radial direction over the entire upper side of the end cap 7. The flow channel extends between the winding space restrictions 11 and provides space below the coil, whereby the casting material can flow below the coil and avoid bubbles. In this embodiment, the flow channel 49 has a rectangular cross section.

[0079] On the end side of the end cap 7, below the flow channel 49, a recess 63 is provided, through which the casting material can flow under the end cap 7. A continuous, axially extending ventilation hole 57 is provided in the flow channel 49, which extends into the cavity 59 below the placed end cap 7. Alternatively or additionally, one or more ventilation holes 57 can be arranged on the radially outward end side 61 of the end cap 7, so that they extend essentially radially. It is also conceivable to position the ventilation holes 57 outside the flow channel 49 on the winding wire support 9.

[0080] Fig. 9 Shown in a three-dimensional bottom view Figure 8 Detail of the end plate 5.

[0081] On the underside of the end cap 7, below the winding wire support 9, support frames 65 are provided, which serve for stability and facilitate the production of the end plate 5 with the end cap 7. Between the support frames 65, the casting material can flow into the cavity 59 below the end cap 7 placed above. The ventilation holes 57 not only allow air to escape, but also facilitate the flow of the casting material, especially when casting in a vacuum, so that no cavities are formed in the hardened casting material.

[0082] The features mentioned above and specified in the claims and evident from the drawings can be implemented advantageously both individually and in different combinations. The invention is not limited to the described embodiments but can be modified in many ways within the capabilities of a person skilled in the art.

[0083] Reference numerals list

[0084] 1 stator core

[0085] 3 stator teeth

[0086] 5 end plate

[0087] 7 End caps

[0088] 9 Winding wire support

[0089] 11 Winding space limitation

[0090] 13 stator winding

[0091] 15-wire guide module

[0092] 17 Concave

[0093] 19 Pillars

[0094] 21 connections

[0095] 23Inner Area

[0096] 25T-shaped area

[0097] 27 walls

[0098] 29 bottom

[0099] 31 Base

[0100] 33 protrusions

[0101] 35 guide groove

[0102] 37 longitudinal side

[0103] 39 Winding Wire

[0104] 41 Edges

[0105] 43 bevel

[0106] 45 Insulation film

[0107] 47 Gap

[0108] 49 Flow Channel

[0109] 53 Groove

[0110] 55 Connectors

[0111] 57 Ventilation holes

[0112] 59 Cavity

[0113] 61 End side

[0114] 63 Gap

[0115] 65 Support frame

Claims

1. A stator, comprising: A stator core (1), the stator core comprising a plurality of stator teeth (3), the stator teeth respectively having a first end side and a second end side, at least one first end cover (7) and at least one second end cover (7), the first end cover and the second end cover respectively comprising a base (31) and a winding wire support (9), the first end cover (7) being arranged on a first end side of one of the stator teeth (3) and the second end cover (7) being arranged on a second end side of the same stator tooth (3), so that the base (31) of the end cover (7) faces the end side, A stator winding (13), the stator winding having at least one winding wire (39), the winding wire being wound around the stator tooth (3) via a first end cap (7) and a second end cap (7), It is characterized in that The winding wire support (9) has two protrusions (33) which protrude from the base (31) on opposite sides, the winding wire (39) extending over the protrusions (33) of the first and second end caps (7), and An insulating film (45) is provided, which comprises an end edge and extends between one of the projections (33) of the first end cover (7) and an opposite projection (33) of the second end cover (7) and is arranged between the winding wire (39) and the stator tooth (3), wherein the winding wire (39) extends over the projection (33) without exerting forces on the end edge of the insulating film (45).

2. The stator according to claim 1, wherein: The projection (33) extends at least along a section of the end-side edge of the insulating film (45), over which the winding wire (39) extends.

3. The stator according to claim 1 or 2, wherein: The insulating film (45) extends beyond the stator core such that the insulating film (45) overlaps the base (31) of the first and second end covers (7).

4. A stator according to any one of the preceding claims, wherein: The insulating film (45) extends between the protrusions (33), and the protrusions respectively have a stopper, which is configured to prevent axial movement of the insulating film (45), and the width of the stopper corresponds to the thickness of the insulating film (45).

5. The stator according to claim 4, wherein: The overlapping length of the section of the insulating film (45) overlapping the base (31) is related to the creepage distance, in particular to a predetermined leakage current resistance.

6. A stator according to any one of the preceding claims, wherein: The insulating film (45) is a first insulating film, which extends along a first longitudinal side (37) of the stator tooth (3), and a second insulating film extends along a second longitudinal side (37) of the stator tooth (37) opposite to the first longitudinal side (37) and between another protrusion (33) of the first end cover (7) and an opposite protrusion (33) of the second end cover (7), and is arranged between the winding wire (39) and the stator tooth (3).

7. A stator according to any one of the preceding claims, wherein: The winding wire supports (9) of the first and / or second end cap (7) each have radially spaced-apart outer and inner winding space delimiters (11).

8. A stator according to any one of the preceding claims, wherein: The projection (33) has a plurality of guide grooves (35) in which the winding wire (39) extends.

9. The stator according to claim 8, wherein: The guide groove (35) has rounded edges, the contour of which is in particular polynomial.

10. A stator according to any one of the preceding claims, wherein: The winding wire (39) of the stator winding (13) is wound by means of a needle.

11. A stator according to any one of the preceding claims, wherein: A flow channel (49), in particular extending radially, extends in the winding wire carrier (9).

12. A stator according to any one of the preceding claims, wherein: Ventilation holes (57) are provided in the end cap (7), which ventilating holes extend in particular radially or axially.

13. The stator according to any one of claims 7 to 12, wherein: The outer winding space limitation (9) is designed as a wall (27) or a plurality of walls (27) protruding axially above the winding wire support, and / or the inner winding space limitation (9) comprises two hollow struts (19) which can be used as connecting elements.

14. A stator according to any one of the preceding claims, wherein: The first and second end covers (7) are included in a plurality of first end covers (7) and a plurality of second end covers (7), wherein the plurality of first end covers (7) and the plurality of second end covers (7) are arranged on a first end side or a second end side of the plurality of stator teeth (3).

15. A stator according to any one of the preceding claims, wherein: The insulating film (45) extends along mutually facing longitudinal sides (37) of two adjacent stator teeth (3).

16. The stator according to claim 14 or 15, wherein: The plurality of first end caps (7) are configured as a one-piece end plate (5) and / or the plurality of second end caps (7) are configured as a one-piece end plate (5), and / or A plurality of the plurality of first end caps (7) are configured as one-piece end plate segments, and / or a plurality of the plurality of second end caps (7) are configured as one-piece end plate segments.

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