DE102017130361A1 - Stator tooth and stator with good electrical insulation and at the same time very high thermal conductivity to increase the performance of electric motors - Google Patents

Abstract

The invention relates to a stator tooth (1) of a rotating field machine having a pole shoe (1a) and a pole core (1b), wherein the stator tooth (1) has longitudinal sides (L) and end faces (S) and is protected by electrical insulation (2, 20, 200) is completely or partially covered or sheathed, which is used for electrical insulation of the winding (5) relative to the stator tooth (1), characterized in that the electrical insulation is formed one or more parts, and at least a portion or region of the insulation (2 , 20, 200) or the entire insulation (2, 20, 200) is formed from a material having a heat-conducting property of greater than 1 W / mK, particularly preferably greater than 5 W / mK.

Description

The present invention relates to a stator tooth for a stator of a rotating field machine according to the preamble of claim 1.

State of the art:

Known induction machines or electric motors are usually designed as permanent-magnet internal or external rotor motors. These are increasingly used as an electric drive motor of two-wheeled vehicles, passenger cars (PKW), trucks (trucks), as well as propeller-driven propulsion systems in the maritime sector and aviation. Efficiency is the primary design choice, especially for vehicles powered by batteries or Li-ion battery, ships, and more recently electric aircraft, since efficiency is the primary factor determining the size of the battery and thus the overall cost. In the overall view, however, the cost of the electric motor must be considered, making a cost-efficient use of various materials is necessary and relevant. In the aviation sector, in particular in electrically powered aircraft, in addition to the efficiency, the power density must also be taken into account, which is why the use of permanent magnets is generally preferred.

In order to achieve high efficiency and power density, various measures are taken to reduce the losses in addition to the use of permanent magnets. A distinction is made between copper losses in the coils, the iron losses in all ferrous and magnetic circuit-relevant engine components, and the friction losses in the bearings.

In order to reduce copper losses, single tooth technique as well as winding of single or double teeth is favored. With the single-tooth winding technique, the exciting coil can be wound precisely, thereby increasing the degree of copper filling in electric motors. In external runners is in addition to single number technique also winding technology with bending stator, as in EP0815860 described, used.

In order to reduce iron losses, laminated stators with a small sheet thickness, in particular Si-Fe sheets with sheet thicknesses <= 0.3 mm and bladed rotors or optionally also used to reduce the eddy current losses and broken permanent magnets. In addition, materials with high temperature resistance, in particular permanent magnets with high remanence and at the same time high coercive force H _CJ , are increasingly being used. This high temperature resistance leads to very high costs, since, for example, such permanent magnets have a high dysprosium content. In addition, stator laminations with very low losses (sheet thickness 0.1-0.2 mm) or high degree of saturation (eg Co-iron sheets) are very expensive.

From the prior art, however, few approaches are known as the performance of the engine can be increased by very efficient heat conduction to increase the heat dissipation of the engine.

In WO 2010/099974 For example, a double rotor is realized with a very complex water cooling. The cooling channels are realized in a thermoset injection molding process and run between the excitation coils from the housing to the winding head and deflected at the winding head. Such cooling is extremely expensive and also not optimal, since winding space for copper coils is lost.

Another approach to heat conduction is in WO2010 / 099975 realized. In this twin-rotor engine, the stator is overmoulded with a thermoset material having good thermal conduction properties. At the same time, emphasis must be placed on rigidity in the selection of the thermoset material, since the encapsulation of the stator contributes substantially to the stability of the self-supporting stator during operation. Next is in WO2010 / 099975 discloses that the encapsulation and the good thermal conduction properties of the thermoset material, the heat transfer from the winding head of the excitation coils can be improved to the housing.

In the WO2010 / 099975 However, the solution disclosed has some weaknesses. On the one hand, in thermoset injection molding, primarily the strength must be taken into account, and thus, in the selection of the material, it is not only possible to emphasize the heat conduction properties. In addition, the method with a material with high strength and high thermal conductivity is very costly because the complete stator receives its final stability and thermal conductivity only in the Duroplastvergussverfahren. The stator teeth must be fixed very solid during the casting process, since the thermoset injection molding is operated with high injection pressures. In addition, a high material use with very expensive fillers (heat conductors such as boron nitride, strength-improving materials such as carbon fiber or glass fiber) is required. Finally, the concept of the double-rotor motor allows thermal conduction in one direction only.

Further common optimization methods are the use of plastic stator teeth end pieces and the insulation of the middle area by a thin Kapton foil with an acceptable conductance (0.12-0.3 W / mK) and sufficient dielectric strength> 2 kV. Such a configuration of the stator tooth is in 1 illustrated. This specific Thermal conductivity of the windings, not shown towards the stator tooth is comparable to the usually made of plastic end pieces. Due to the thinness of the Kapton film, however, more heat can be transferred via this heat path. The thin film reduces the heat path from the excitation coil to the stator and increases the degree of copper filling, since the thin-walled Kapton film allows more space for the copper coils in the winding window. However, this isolation technique is primarily used to improve the degree of copper filling of the electric motors. An improved cooling performance does not result because usually the coil is not applied to the Kapton film and thus there is a certain air gap between the hot coil and the heat dissipating Kapton film and the exciter coil, which is due to the lack of precision in the winding technique.

Object of the invention

The object of the invention is to improve the heat dissipation of the windings on the stator tooth or stator.

Solution of the task

This object is achieved with a stator tooth according to claim 1 and a stator according to claim 11. Advantageous embodiments of the stator tooth or stator result from the features of the subclaims.

The invention is based on the idea of improving the heat dissipation from the windings via the stator teeth. The necessary electrical insulation is made of a material with high electrical breakdown strength, at the same time the insulation wholly or partially a high thermal conductivity, in particular greater than 1 W / mK, more preferably greater than 5W / mK. The electrical insulation may be formed in one or more parts, wherein at least a portion or region of the insulation or the entire insulation has a thermal conductivity of greater than 1 W / mK, preferably greater than 5 W / mK.

The stator tooth has a pole shoe and a pole core and in each case has two longitudinal and end sides, wherein in particular the pole core is completely or partially covered or sheathed by the electrical insulation, which serves to electrically insulate the winding with respect to the stator tooth.

In an advantageous first embodiment, the electrical insulation can have two or more insulating bodies each encompassing an end face of one or more stator teeth. These may advantageously have grooves on their outside facing the winding for guiding the coil wires of the winding (s). This insulating body can be pushed in the axial direction of the stator tooth or stator. However, it is also possible that the insulating body are molded onto the stator tooth or stator. They can be formed from a thermoplastic or thermosetting plastic.

In a second possible embodiment, the electrical insulation is formed by a potting compound, which is applied by means of an injection molding process to the stator tooth or all stator teeth of the stator simultaneously. This potting compound may be formed of a thermoplastic or thermosetting plastic. If, apart from the potting compound, no further measures are provided to increase the thermal conductivity of the insulation, the potting compound is formed by a thermoset having a thermal conductivity of greater than 1 W / mK, preferably greater than 5 W / mK.

Advantageously, at least one, in particular solid and dimensionally stable, heat-conducting element, in particular in the form of a plate, abut against at least one longitudinal side of one or all of the pole cores in the two embodiments described above. Each heat-conducting element can in this case be inserted in a recess provided for it, in particular window-like, of the electrical insulation, which is formed by pushed-on insulating bodies or an injection molding compound. Advantageously, the heat-conducting element can have a thermal conductivity of greater than 5 W / mK.

However, it is also possible that the heat-conducting elements are arranged in the axial direction between two insulating bodies, which are each injected in the axial direction on the end faces of the stator tooth or stator sprayed onto the end faces. In this case, the insulating body to form a window for receiving the heat-conducting element may extend axially along the heat-conducting element, such that touch the two disposed on opposite end faces insulator. In this embodiment, at least the heat-conducting element has a thermal conductivity of greater than 5 W / mK.

The heat-conducting elements are advantageously located directly on as large a part of the side surface or the entire longitudinal side of the pole core and can be made of ceramic or ceramic-based.

Advantageously, the heat-conducting element can have a greater thickness than the adjacent wall region of the insulating body or of the insulation, so that it is ensured that the heat-conducting element is in good contact with the coil wires of the winding (s).

It is also advantageous if the side of the heat-conducting element facing the winding is adapted to the contour of the winding, for example being concave or convex and / or grooved in cross-section, so that as far as possible all external coil wires of the adjacent winding (s) are formed the heat conduction element with the largest possible area and thus ensure the best possible heat transfer is guaranteed.

It goes without saying that the stator tooth described above can be a stator tooth of an external stator or an internal stator.

Likewise, a stator is claimed which has a plurality of stator teeth described above. Of course, the stator teeth can be formed as known from the prior art. In addition, they can be connected to each other via an inner ring (inner stator) or outer ring (outer stator). They can be integrally formed with the ring or pushed axially with its pole core on the ring and held in a form-fitting manner in the radial direction.

The stator according to the invention may have axially end-side insulating body, which engage around several or all stator teeth of the stator end side according to the first embodiment described above. However, it is also possible that the electrical insulation by means of an injection molding compound (second possible embodiment) is formed, wherein the injection molding compound may be a thermosetting plastic or a thermoplastic and enclose at least the pole cores completely or with the exception of recesses for receiving heat conducting elements.

In this case, two adjacent stator teeth each form a winding groove whose groove base is formed by the wall of the stator teeth connecting ring. The electrical insulation can also cover the groove bottom of the winding grooves. Thus, the front-side insulating parts described above can also extend over the groove bottom. However, it is also possible that the injection molding compound forming the electrical insulation covers the groove base and thus forms the electrical insulation. Also, separate inserts, which extend axially along the groove bottom and abut against this, may be provided. These may have on their side facing the winding groove a shape which is adapted to the adjacent windings, so that their outer coil wires abut the insert and a good heat transfer is achieved.

The space between the windings in the winding grooves can be cast advantageously in all the possible embodiments described above additionally by means of a further potting compound, such that no air between the coil wires of the windings longer exists. This potting compound may advantageously have a thermal conductivity of greater than 0.25 W / mK, preferably greater than 1.0 W / mK.

Through the targeted use of insulating heat conductors for the heat-conducting elements according to the invention, ie special materials with very good thermal conduction properties> 1 to 100 W / mK and at the same time high dielectric strength> 5 kV / mm (plates, pins preferably of boron-nitride or other ceramics, such as alumina or nitride with thermal conductivities of up to 30 to 100 W / mK and silicon carbide of up to 130 W / mK), the heat transfer can be optimized by the heating coil due to the copper losses exciting coils to the stator. Alternatively, a composite material made of a plastic compound with admixtures of thermally conductive material can be used, whereby any heat conduction properties at low cost manufacturability are made possible at low material costs. These compounds are advantageously used in the complete extrusion of stators or single teeth. In this way, we advantageously achieve the lowest possible specific temperature gradient relative to the engine losses ΔT / P _{V, the engine} between the heat sink and the loss sources in the interior of the engine.

As a result of the invention, a broadening of the thermally stable power range of the electric motor is advantageously achieved since the components of the electric motor are only permitted up to a respective maximum operating temperature. Thus, excitation coils can usually up to 200 ° C and permanent magnets of the rotor in magnetic opposing field to max. 160 ° C are operated. If the temperature gradient between the heat sink and the loss source is optimized by very good heat conduction, the copper losses are reduced, since the copper resistance decreases with temperature and, secondly, the electric motor can be operated at higher currents or, alternatively, less copper can be used with the same output due to better heat dissipation. Less copper reduces weight and manufacturing costs. Also, in terms of cost optimization, expensive stator laminations, e.g. be dispensed with 0.1 - 0.2 mm sheet thickness, if the higher losses are optimized by appropriate heat conduction.

Hereinafter, possible embodiments of the invention will be explained in more detail with reference to drawings.

• 1: Statorzahn mit Isolierfolie typischerweise aus Kapton, nach dem Stand der Technik;
• 2a: perspektivische Darstellung eines erfindungsgemäßen Statorzahns mit zwei stirnseitigen Isolierkörpern und axial dazwischen angeordnetem Wärmeleitelement;
• 2b: eine Querschnittsdarstellung durch den Statorzahn gem. 2a im Bereich eines Isolierkörpers;
• 2c und 2d: Seitenansichten auf den Isolierkörper;
• 2e: Seitenansicht und Querschnittsdarstellung durch ein Wärmeleitelement;
• 3: Statorzahn wie in 1b, wobei jedoch die stirnseitigen Isolierkörper über die gesamte axiale Länge des Statorzahns mit möglichst kleiner Trennfuge bedecken und zusammen jeweils eine fensterartige Ausnehmung für die Aufnahme eines Wärmeleitelementes an mindestens einer Polkernlängsseite bilden.
• 4: erfindungsgemäßer Statorzahn mit einer umspritzten Isolierung, welche an jeder Polkernlängsseite zwei Ausnehmungen zur Aufnahme von jeweils einem Wärmeleitelement bildet;
• 5: erfindungsgemäßer Statorzahn mit einer umspritzten Isolierung aus einem Duroplast mit einem Material mit guter Wärmeleitfähigkeit;
• 6: vier mögliche Ausführungsformen eines Stators, wobei jeweils in einem Quadranten A bis D eine mögliche Ausführungsform eines Stators dargestellt ist.

Show it:

• 1 : Stator tooth with insulating film typically made of Kapton, according to the prior art;
• 2a : perspective view of a stator tooth according to the invention with two end-side insulating bodies and axially interposed heat conducting element;
• 2 B a cross-sectional view through the stator tooth acc. 2a in the region of an insulating body;
• 2c and 2d : Side views of the insulating body;
• 2e : Side view and cross-sectional view through a heat conducting element;
• 3 : Stator tooth like in 1b However, wherein the end-side insulating body over the entire axial length of the stator tooth cover with the smallest possible parting line and together each form a window-like recess for receiving a heat conducting element on at least one Polkernlängsseite.
• 4 : Statorzahn according to the invention with an overmolded insulation, which forms two recesses on each Polkernlängsseite for receiving in each case a heat conducting element;
• 5 : Stator tooth according to the invention with an overmoulded insulation made of a thermoset with a material with good thermal conductivity;
• 6 Four possible embodiments of a stator, wherein in each case in a quadrant A to D, a possible embodiment of a stator is shown.

The 1 shows a stator tooth 1 in single-tooth winding technique with insulating bodies 2 on the front side S of the stator tooth 1 and an insulation film 3 in the groove in the area of the pole core 1b according to the prior art. These so-called insulating body 2 are preferably made of cheap and injection-moldable plastics and offer at the same time through the surface 2a . 2d the insulating body 2 Support for manufacturability. In particular, by the geometry 2a . 2d the insulating body 2 the windability of the first conductor layer of the stator winding can be specified and has an advantageous effect on the degree of filling of the copper on the stator tooth. The disadvantage, however, is that the plastic of the insulator 2 as well as the insulation film 3 not only reduces the electrical conductivity, but also thermally has an insulating effect.

The 2a shows a possible embodiment of a perspective tooth according to the invention shown in perspective 1 , which like the one in 1 illustrated stator tooth 1 with insulators 2 is provided on the winding head, but with the difference that the conventionally used insulation film 3 , which is typically made of Kapton, has been replaced by a heat conducting element 4 in the form of a plate. The heat-conducting element 4 has a much higher thermal conductivity and a high dielectric strength. It can be made of a material such as ceramic or ceramic-based material. This is advantageous on each longitudinal side L of the pole core 1b at least one heat conducting element 4 arranged, this (s) as large as possible on the pole core 1b abuts (s), more preferably on the entire longitudinal side L of the pole core 1b , The thus significantly increased thermal conductivity in the groove allows the cooling path of the exciter coil 5 to the stator tooth 1 to significantly improve.

As in 2 B can be seen, is the insulating body 2 with its inside over the entire surface of the pole core 1b and areas of the magnetic return of the pole, so the Polrückschlusses 1c and the pole shoe 1a on.

Each insulating body has a frontal area 2a on, in the area of the transition from the pole core 1b towards the pole piece 1a a collar-shaped section 2 B borders. In the area of the transition from the pole core 1b towards the pole conclusion 1c also borders a collar-shaped section 2c to the middle area 2a on. The insulator 2 is not just on the front 1 of the stator tooth 1 but also engages laterally around this and is also located on a short section of the long side L of the stator tooth, in particular in the region of the pole core 1b with his area 2d on ( 2c and 2d) , The area 2d points in the area of the pole core 1b also on its outer surface grooves for guiding the first layer of the coil wires of the field winding on. The area of the polkernel 1b forms together with the pole conclusion 1c and the pole piece 1a a groove N for receiving the coil wires or the winding.

2e shows a possible embodiment of the heat conducting element according to the invention 4 , which is a rectangular plate with a thickness D is trained. The fat D should be designed thicker advantageous than the thickness of the lateral projections 2d the insulating parts 2 to ensure that the heat conducting element 4 is in direct contact with the inner layer of the coil wires. The heat-conducting element 4 is made of a material with high thermal conductivity (> 5 W / mK) at the same time has a high electrical insulation capacity. For example, it can be made of boron nitride.

The 3 shows another possible optimization of the in the 2a-e illustrated and described stator tooth according to the invention. Each is an insulating body 2 at the two winding heads of the stator tooth 1 disposed the insulation body 2 in addition to the function of electrical insulation and the improvement of Spulenwickelbarkeit a holding device for the both sides of the pole core 1b arranged Wärmeleitelemente 4 form. The heat-conducting element 4 can be the same as in the embodiment according to the 2a to 2f ,

The 4 shows a further possible embodiment of a stator tooth according to the invention 1 in which the electrical insulation 200 directly to the stator core 1b sprayed. At the same time, the upper collar can be used during the encapsulation process 200b and the lower collar 200c as well as the groove bottom with grooves 200a be formed for improved wire guidance. In addition, during the extrusion process by means of at least one slide one or more recesses 200e for subsequently insertable heat conducting elements 4a kept free. Alternatively, after encapsulation, the outer contour 200a be exposed by machine.

The 5 shows a further variant of Statorzahnumspritzung, wherein the insulation body 7 . 7a . 7b . 7c . 7d in thermoset process directly to the stator core 1b is injected. The granules which are used for Statorumspritzung already contains the required for an optimized heat transfer ceramic admixtures. This results in a component, which is optimized both in terms of mechanical and thermal stability, electrical insulation and heat-conducting effect.

In the embodiments of the 2 to 4 become the insulating Wärmeleitelemente 4 . 4a between coil and stator along the axial extent of the stator tooth and serve a significantly improved heat transfer between the coil and stator over approximately the entire axial length of the stator. In the winding head area or end face S of the stator teeth 1 are preferably wire-leading and insulating plastic end pieces in the form of insulators 2 . 20 provided, which may be placed or molded. In this case, the heat-conducting elements 4 . 4a either frictionally by the insulator 2 . 20 be positioned or positively connected to the stator tooth, so that if possible, a very small distance and sufficient stability can be realized.

Alternatively, the stator tooth, as in 4 represented and described in the thermoplastic injection molding process with a standard plastic to be encapsulated and an area along the side surfaces of the pole core 1b be recessed so that there in a subsequent step, one or more heat conduction plates 4a or a composite concept with a plurality of heat-conducting elements can be inserted.

Furthermore, the stator tooth, as in 5 represented, completely by thermoset injection molding with a thermally conductive material with high specific conductance, for example, boron nitride thermoset material to be encapsulated. In terms of process technology, this is far less complicated than overmolding the entire stator since the injection mold can be made significantly simpler. Also, it is not necessary to place emphasis on strength-enhancing fillers, but it is only a good heat-conducting and insulating material can be selected.

In all the embodiments described above, it makes sense to cast or steal the stator after the winding process in order to completely avoid air pockets between the copper wires and the coil-near stator insulation and thus to further optimize the thermal transition between the exciter coil and the stator. As potting material, a material with acceptable thermal conduction properties can usefully be used, with a specific conductance of 0.25-1 W / mK. A potting material with moderate thermal conductivity is always a factor 10 better than air, since air has a very low specific conductance of only 0.026 W / mK. By using the potting material, the transition between the coil layers on the stator and the insulating film and between the coil layers, for example, first and second coil layer, thus significantly improved.

The 6 shows the example of an external rotor in its four quadrants A - D four possible embodiments of an inner stator 100 , All stators in the quadrants A - D is common that the stator teeth have an inner ring 1f are integrally connected to each other. The inner stator can be made laminated. The embodiments shown may of course also be provided in an external stator of an internal rotor.

In quadrant A is shown an embodiment in which the entire stator 100 is encapsulated with a thermoset, as in the embodiment according to 5 , wherein no additional heat conducting elements are provided more. The thermoset has a thermal conductivity of more than 1 W / mK. Optionally, the winding groove WN after the winding process with an additional potting compound F potted or sprinkled to avoid air inclusions between the copper wires and the coil near stator insulation as completely as possible and thus to further optimize the thermal transition between excitation coil and stator.

In the quadrant B an embodiment is shown in which the stator teeth or Polkerne 1b are encapsulated with a thermoplastic, wherein in recesses 200e in the thermoplastic in the area of the long sides L the pole cores 1b are provided in the after the injection process heat conducting elements 4 . 4a can be inserted. The stator teeth are analogous to those in 4 formed trained.

The heat-conducting elements are thicker than the insulation and preferably convex.

In the quadrants C and D are embodiments of a stator according to the invention 100 shown, in which an insulation 7 by means of a spraying method analogous to the variants in the quadrant A or B are provided, in addition not yet shown heat-conducting 4 . 4a can be provided along the Polkernlängsseiten. At the bottom of the groove G the winding grooves WN are additional inserts 9 . 10 arranged, which at the bottom of the groove G abut the entire surface and, if necessary, one corresponding to the bottom of the groove G have curved wall. These inserts 9 . 10 are also designed as heat-conducting elements and preferably have a high thermal conductivity, in particular greater than 5 W / mK on. They can be made of boron nitride, for example. In the embodiment in the quadrant C are the inserts 9 plate-shaped or cup-shaped, whereas in the quadrant D have a web-shaped projection extending in the axial direction, with its two sides against the radial inner side of the windings 5 suppressed. In addition, even between the pole piece 1a and the radial coil end 5a the windings still heat conducting elements 11 einliegen, which are made of the same material as the parts 9 . 10 are made.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• EP 0815860 [0004]
• WO 2010/099974 [0007]
• WO 2010/099975 [0008, 0009]

Claims (15)

Statorzahn (1) an induction machine, a pole piece (1a) and a pole core (1b) comprising, wherein the stator tooth (1) has longitudinal sides (L) and end faces (S) and of an electrical insulation (2, 20, 200) or the whole partially covered or sheathed, which is used for electrical insulation of the winding (5) relative to the stator tooth (1), characterized in that the electrical insulation is formed in one or more parts, and at least a portion or region of the insulation (2, 20, 200) or the entire insulation (2, 20, 200) is formed from a material with a heat-conducting property of greater than 1 W / mK, preferably greater than 2.5 W / mK. Stator tooth (1) to Claim 1 , characterized in that the electrical insulation (2, 20) has two respective end faces (S) embracing insulating body (2, 20), in particular on its the winding (5) side facing grooves (R) for the coil wires of the winding ( 5). Stator tooth (1) to Claim 1 , characterized in that at least one longitudinal side (L) of the pole core (1b) at least one, in particular solid and dimensionally stable, heat-conducting element (4), in particular in the form of a plate rests, which between two in each case one end face (S) embracing insulating bodies (2 , 20), in particular in recesses (20e) of the insulating body (20), wherein at least one heat-conducting element (4) has a thermal conductivity of greater than 5 W / mK, preferably greater than 10 W / mK, particularly preferably greater than 20 W / mK, has, in particular on ceramic or Siliziumcarbidbasis or made of boron nitride composite materials is manufactured and / or the heat conducting element (4) has a thermal conductivity which is at least a factor of 2, preferably greater than 5 times that of the insulating body (2, 20). Stator tooth (1) to Claim 3 , characterized in that the heat-conducting element (4) directly on a part or the entire side surface of the pole core (1b) and is made of ceramic or ceramic-based and has both electrically insulating properties and a thermal conductivity> 10 W / mK, particularly preferred Alumina or nitride ceramic or silicon carbide or boron nitride. Stator tooth (1) according to one of the preceding claims, characterized in that the electrical insulation (200) or at least one insulating body (2, 20) by means of encapsulation of the stator tooth (1), in particular by encapsulation of at least the pole core (1b) is formed, wherein the potting material is a thermoplastic or a thermosetting plastic, wherein the thermoset in particular has a thermal conductivity of greater than 1 W / mK, preferably greater than 5 W / mK. Stator tooth (1) to Claim 5 , characterized in that the formed by encapsulation electrical insulation (200) at least one window-like recess (200e) or a recess with thin-walled area for particular positive reception of at least one heat conducting element (4), wherein the heat conducting element (4) laterally on the pole core (1b ) is arranged, in particular rests against this and has a thermal conductivity of greater than 5 W / mK, in particular made of boron nitride. Stator tooth (1) after one of Claims 3 to 6 , characterized in that the heat-conducting element (4) has a greater thickness (D) than the adjacent wall region (2d, 20d, 200d) of the electrical insulation (2, 20, 200). Stator tooth (1) after one of Claims 3 to 7 , characterized in that the winding (5) facing side (4w) of the heat-conducting element (4) of the outer contour of the winding (5) is adapted, in particular convex in cross-section. A stator (100) having a plurality of stator teeth (1) according to any one of the preceding claims forming an outer or inner stator. Stator (100) after Claim 9 , characterized in that the stator teeth (1) are connected to an annular region (1f). Stator (100) after Claim 9 or 10 , characterized in that the end-side insulating body (2, 20) engage around a plurality or all of the stator teeth (1) of the stator (100). Stator (100) after Claim 11 , characterized in that the electrical insulation (2, 20, 200) is formed by means of an injection molding compound, wherein the injection molding compound is a thermoset or a thermoplastic, and at least the pole cores (1b) completely or with the exception of recesses (200e) for receiving Heat conducting elements (4, 4a) encloses. Stator (100) after Claim 11 or 12 , characterized in that two stator teeth (1) between them form a winding groove (WN) whose groove bottom (G) through the annular portion (1f) is formed, wherein the electrical insulation (2, 20, 200) and the groove bottom (G ) of the winding grooves (WN) and formed by the injection molding compound or by separate inserts (9, 10) which extend axially along the groove bottom (G) and abut the groove base (G). Stator (100) after one of Claims 11 to 13 , characterized in that between two stator teeth, of which at least one wound (5), near the pole pieces (1a), a heat conduction member (11) is inserted in the winding groove (WN) having a heat conductivity of greater than 5 W / mK and extending in the axial direction of the stator (100). Stator (100) after one of Claims 1 to 15 , characterized in that the space between the windings (5) in the winding grooves (WN) by means of an additional potting compound (F), in particular with a thermal conductivity of at least 0.25 W / mK, is shed, in particular such that no more air pockets between the coil wires of the windings (5) are more present.

Images