Stators for electric motors

Abstract

The invention relates to a stator (6) for an electric motor (2), the stator comprising a stator base body (16) having star-shaped stator teeth (17) and a stator yoke (22), wherein a certain number of axial grooves (26) are arranged on the outer circumference (24) of the stator base body (16), and spring elements (28) protruding radially on the circumference of the stator base body (16) are radially inserted into the axial grooves in a form-locking manner.

Description

Technical Field

[0001] The invention relates to a stator for an electric motor, in particular for an electric motor of a motor vehicle, comprising a stator base body with stator teeth arranged in a star shape and a stator yoke. The invention also relates to an electric motor having such a stator arranged in a motor housing and a spring element for such a stator. Background Art

[0002] In modern motor vehicles, electric motors are used in many ways as drives for various adjustment elements. For example, electric motors can be used as window lift drives, sunroof or seat adjustment drives, steering drives (EPS, Electric Power Steering), cooling fan drives or transmission actuators. Such electric motors must have a relatively high torque density or power density and must also be reliable in operation even at high temperatures.

[0003] An electric motor as an energy converter from electrical energy to mechanical energy comprises a stator forming the stationary motor part and a rotor forming the moving motor part. In the case of an inner rotor motor, the stator is usually provided with a stator yoke on which stator teeth are arranged projecting radially toward the center (this means in a star shape inwards), the free ends of the stator teeth facing the rotor forming so-called pole shoes. Windings or coils are applied to the stator teeth, which are interconnected to form a stator winding and generate a magnetic field during electric operation. In order to guide and intensify the magnetic field generated by the energized windings, the stator material is usually metallic, for example made of soft magnets.

[0004] For reliable and noise-reduced motor operation, it is necessary that the stator is securely supported in the motor housing. In particular, the anti-twist of the stator is desirable, which prevents the stator from tangential torsion or prevents such mechanical torsion.

[0005] In electric motors, the stator is usually supported by a press fit with the housing or by means of additional damping or decoupling elements. Here, the stator is pressed into the motor housing in a non-positive manner or is spliced ​​under load.

[0006] If the stator is fixed and supported by a press fit, the deformations caused by the electromagnetic forces during the operation of the motor are directly transmitted to the motor housing. In particular, in the case of synchronous motors in motor vehicles, the stator is deformed by the electromagnetic forces caused by operation, wherein such deformations can become very large, for example in a 10-pole electric motor, so that high structure-borne noise is transmitted to the motor housing that accommodates the stator. Therefore, in order to reduce the transmission of structure-borne noise, the stator should be decoupled from the housing. If the stator is supported by damping or decoupling elements, additional elements may be required to fix the stator and prevent it from twisting.

[0007] DE 10 2013 009 407 A1 discloses a stator for an electric motor, which is composed of a star-shaped stator lamination stack and a cylindrical stator yoke formed by stacked annular plates, wherein the star-shaped stator lamination stack is placed in the stator yoke, wherein a certain number of annular plates each have at least one bending tongue on the outer peripheral side. With the help of the radially extending bending tongues, it is possible to achieve fixation in the case of centering and positioning the stator at the same time in the housing. Here, the stator only uses the abutment points (which are formed by the bending tongues) arranged at the exposed parts to abut against the inner wall of the housing in the spliced ​​state. If each annular plate is provided with notches (the bending tongues are bent into these notches before or during the splicing process of the stator and the housing), then a space-saving structure of an electric motor with a stator placed in its housing can also be achieved.

[0008] JP 2014-018001 A1 discloses fixing the stator of an electric motor in a motor housing in a predetermined position by means of a spring tongue, wherein the fixing tongue is held on the housing with one end and the other end of the fixing tongue (which extends obliquely into the housing interior) is located in an axial splicing groove on the outer circumference of the stator.

[0009] DE 10 2007 058 072 A1 discloses an electric motor with a stator, which is constructed from a laminated core and is arranged in a housing, wherein the laminated core is held together by means of spring clips, which overlap the laminated core in the axial direction and support the laminated core radially against the inner wall of the housing. The spring clips have springbacks that protrude radially from the outer circumference of the laminated core and clamping feet on opposite narrow sides, which overlap the laminated core at the end. Summary of the invention

[0010] The object of the present invention is to specify a particularly suitable stator for an electric motor. In particular, the stator should be particularly suitable for reducing the transmission of structure-borne noise to the motor housing in terms of decoupling. The stator should be easily arrangable or installed in the housing and decoupled from the housing. In addition, it should be possible to prevent the stator from twisting in the motor housing. The object of the present invention is also to specify a particularly suitable electric motor with such a stator in a housing (motor housing) and a particularly suitable spring element for such a stator.

[0011] According to the invention, this object is achieved with respect to the stator by the features of claim 1, with respect to the electric motor by the features of claim 9, and with respect to the spring element by the features of claim 10. Advantageous embodiments and developments are the subject matter of the respective dependent claims.

[0012] The stator according to the invention is provided for an electric motor, in particular for an electric motor of a motor vehicle, and is suitable for this purpose and is designed for this purpose. For this purpose, the stator has a stator base body with a stator yoke as a magnetic back iron and a number of stator teeth, which extend radially inwards in the direction of a central stator axis or motor axis and terminate in so-called pole shoes. The stator base body is designed as a solid body, for example in a so-called single-tooth design or star yoke design, wherein the stator teeth are inserted into a cylindrical stator yoke, for example, as star rings.

[0013] A number of axial grooves are provided on the outer circumference of the stator base body, into which spring elements are inserted radially and preferably tangentially in a form-fitting manner, which spring elements protrude radially on the circumference of the stator base body. According to the invention, the or each spring element thus protrudes radially at least partially beyond the outer circumference. In other words, at least one spring element protrudes radially from the axial groove at least in sections.

[0014] Here and below, a "positive fit" or "positive connection" between at least two interconnected components is understood to mean in particular that the interconnected components are held together at least in one direction (here the radial direction in relation to the central axis of the stator and the axis of rotation of the electric motor) by direct engagement of the contours of the components themselves with one another. The "blocking" of mutual movement in this direction (here the radial direction) is thus achieved in a form-dependent manner. In the present case, the splicing element is therefore held radially and positively in the axial groove of the stator tooth.

[0015] Here and below, an “axial groove” is understood to mean, in particular, radially inwardly directed grooves or groove-like recesses of the outer circumference which extend in the axial direction of the stator.

[0016] Here and below, “axial” or “axial direction” is understood to mean, in particular, a direction parallel (coaxial) to the rotation axis of the electric motor, i.e., perpendicular to the end face of the stator. Correspondingly, here and below, “radial” or “radial direction” is understood to mean, in particular, a direction along the radius of the stator or the electric motor, oriented perpendicularly (transversely) to the rotation axis of the electric motor. Here and below, “tangential” or “tangential direction” is understood to mean, in particular, a direction along the circumference of the stator or the electric motor (circumferential direction, azimuthal direction), i.e., perpendicular to the axial direction and radial direction.

[0017] The stator can be fixed radially in the motor housing by means of a spring element which at least partially protrudes radially from the outer circumference or radially extends from the axial groove. In particular, a spring element can be used to support the stator in the motor housing in an elastic and thus damped or vibration-damped manner. Furthermore, the spring element also provides a torsion-proof locking of the stator with respect to mechanical torsion in the motor housing. This provides a stator which is particularly suitable for the electric motor.

[0018] In a preferred embodiment, the axial groove or each axial groove is implemented as a radial undercut or radial undercut of the periphery. Thus, a reliable and operationally safe radial form-locking retention or fixation of the spring element in the axial groove is achieved in a structurally simple manner.

[0019] Preferably, the spliced ​​element used as a decoupling element or damping element, which is placed in the respective axial groove of the stator base body on the yoke side or the back iron side, in particular by being moved in or inserted in the axial direction, undercuts the undercut formed in the axial groove in a suitable manner. For this purpose, the respective axial groove is, for example, dovetail-shaped or T-shaped in cross section. It is important that the axial groove provides a radial undercut, which is at least partially undercut by the spring element. Also conceivable are other shapes (cross-sectional shapes) of the axial groove, such as a pitch circle shape or a T-shape, which has a local protrusion or a local depression (stressed rib) in the groove bottom of the horizontal T-shaped side of the axial groove.

[0020] Preferably, an axial groove is used, which is described, for example, in the as yet unpublished German application (case number 102019208426.5) filed by the applicant on June 11, 2019. The disclosure thereof, in particular the claims thereof (and the related elaborations), are hereby expressly included in the present application. With regard to the radial undercut of the axial groove, specific reference is made to claims 2 and 3, the related embodiments, in particular on pages 3 / 4 and 8 / 9, and Figure 6 to 1 2.

[0021] In an advantageous embodiment, the spring element has a preferably lamellar or strip-shaped base body and at least one first coupling spring or spring arm which is tilted in the radial direction and projects from the axial groove. This allows a reliable, damped or vibration-decoupled mounting of the stator in the motor housing.

[0022] In a suitable embodiment, the first coupling spring, which is also referred to as a radial spring below, is connected to the base body in one piece, i.e. in one piece or in a single piece. Here, the radial spring is in particular configured as a spring-elastic tongue of the base body. The radial spring is therefore connected to the base body at the fixed end and extends radially from the axial groove at least partially with a free end. The spring element arranged in the axial groove preferably forms a (mechanical) interface to the motor housing, in which the stator is installed. The interface has, in particular, a decoupling, damping, clamping, positioning and / or fixing effect (function). In the installed state in which the stator is accommodated in the motor housing, the free end of the radial spring bounces or elastically rests on the inner wall of the motor housing.

[0023] The spring element preferably has more than one radial spring, that is to say a certain number of radial springs or at least two radial springs. The number of radial springs is preferably adapted to the respective running part length of the stator. In other words, it is possible to provide spring elements with a different number of radial springs for different structural sizes of the stator. This allows a particularly flexible and appropriate coordination of the stator support with the acoustic properties during motor operation.

[0024] In order to additionally or further improve the acoustic properties, for example, the width of the radial spring and / or the material thickness of the radial spring and thus its spring strength or restoring force can be flexibly adapted to the respective electric motor and / or the respective application situation. The conjunction "and / or" is to be understood here and below as meaning that the features linked by this conjunction can be formed both jointly and as alternatives to one another.

[0025] The base body protrudes beyond the first coupling spring or radial spring on both sides transversely to the axial direction in the circumferential direction or in the tangential direction. With the azimuthally protruding sections on the longitudinal sides extending in the axial direction, the base body undercuts the (azimuthally) groove sides of the axial groove extending in the circumferential direction of the stator, thereby establishing a radial form fit between the spring element and the respective stator tooth.

[0026] In a suitable development, the spring element has a second coupling spring on the narrow side or end side of the base body, which second coupling spring protrudes axially from the axial groove. The axial groove extends substantially over the entire axial structural length of the stator, so that the second coupling spring stands axially from the stator end side. Therefore, the second coupling spring is also referred to as axial spring in the following. Due to the axial spring, the spring element is therefore also provided for the axial support and fixing of the stator in the motor housing and is suitable and designed for this purpose.

[0027] In an expedient embodiment, the spring element or the axial spring has in a suitable manner a contact edge or a contact surface, by means of which the splice element rests against the end face of the stator base body, in particular in the region of the respective stator tooth.

[0028] An advantageous functional integration is achieved by the radial spring and the axial spring. In particular, the spring element is thus multifunctional and achieves radial support and tangential anti-twist protection as well as axial support of the stator.

[0029] Here, the spring ends or free ends of the radial springs bear against the motor housing in a form-locking and / or force-locking manner. The radial springs act as a primary protection against mechanical torsion of the stator in the tangential direction. Here, the axial springs act as an additional secondary protection against torsion, for example by pressing the stator with an axial force at the bearing cap by means of the axial springs. Here, the axial springs are supported on the stator lamination stack by means of a bearing edge or a bearing surface and are compressed in the spring installation space relative to the motor bearing cap. Furthermore, the secondary protection of the tangential locking by the axial springs can also act as a primary protection against axial movement of the stator.

[0030] Reliable radial and axial support and fixation of the stator as well as rotational protection are thus achieved by the multifunctional spring element.

[0031] A "non-positive fit" or "non-positive connection" between at least two components connected to one another is understood here and hereinafter to mean in particular that the components connected to one another are prevented from sliding against one another due to friction forces acting between them. If the "connecting force" causing the friction forces (that is, the force pressing the components against one another, such as a screwing force or the force of gravity itself) is absent, the non-positive connection cannot be maintained and is therefore released.

[0032] An additional or further aspect of the invention provides that the spring element has at least one clamping claw or claw-like nose on the longitudinal side of the base body for tangentially and / or axially fastening or fixing in the axial groove. The respective clamping claw is bent up from the plane of the base body of the spring element in a suitable manner. This achieves a reliable fixation (holding, fastening) of the spring element in the axial groove of the stator base body assigned to the spring element. This means that the spring element is implemented in a claw-shaped design so as to tangentially and / or axially grip in the axial groove. This ensures a reliable form-locking and / or force-locking fixation of the spring element in the tangential direction. Preferably, the clamping claws or claw-like noses are arranged in pairs on the opposite longitudinal sides of the base body. For example, three pairs of clamping claws are provided on the base body.

[0033] In a particularly structurally simple embodiment, the spring element is designed as an integral, i.e. one-piece or single-piece stamped and bent part. In this context, integral means, in particular, that at least one radial spring and one axial spring as well as the clamping jaws are designed integrally with the base body. This allows a particularly cost-effective embodiment of the spring element with fewer components, which is advantageously transferred to the production costs of the stator.

[0034] The electric motor according to the invention has a motor shaft (rotor shaft) and a rotor fixed relative to the shaft, as well as a stator and a housing as described above, in which the stator is arranged in the housing in a manner decoupled from structure-borne noise, clamped and / or damped, in particular, by means of a spring element which is axially arranged in an axial groove on the outer circumference and radially held therein in a form-fitting manner. The stator is supported on the bearing shield of the electric motor by means of the axial spring of the spring element which is arranged in the axial groove, so that the stator is also decoupled from the bearing shield or damped relative to the bearing shield.

[0035] The advantages and embodiments listed with regard to the stator can also be transferred to the electric motor according to the invention and vice versa.

[0036] The stator according to the invention improves the acoustic properties of the electric motor during motor operation, since the vibrations and / or oscillations generated by the stator are substantially not transmitted to the motor housing as structure-borne noise due to the spring element. In other words, the vibrations and / or oscillations are transmitted to the motor housing with reduced structure-borne noise amplitude. In particular in the case of installation close to the driver's cabin of a motor vehicle, for example in the use of the electric motor as a steering motor, the reduced noise generation is advantageously transferred to the user or driver comfort.

[0037] The spring element according to the invention is arranged to be used in the above-mentioned electric motor or stator and is suitable for this and is designed for this purpose. Here, it is meaningful that the embodiments related to the spring element are also applicable to the stator and / or the electric motor and vice versa.

[0038] The spring element is designed in particular for insertion or insertion into an axial groove of the stator, preferably in a radially positively locking manner. For this purpose, the spring element has a base body with at least one first coupling spring, which is preferably introduced into the base body as a punched tongue and bent out of the plane of the base body. In addition, the spring element has a second coupling spring, which is arranged on the narrow side or end side of the base body. This achieves a particularly suitable spring element. In particular, a multifunctional spring element is thus achieved, which allows radial and axial support and fixation of the stator in the motor housing and anti-twist protection.

[0039] In the installed state, the spring element is preferably received radially and form-fittingly in the axial groove of the stator, wherein the base body is provided in a suitable manner with clamping jaws for, in particular, tangential fixation in the stator groove. As a result, the spring element is automatically fixed relative to the axial groove. Preferably, the spring element has three first coupling springs and one second coupling spring. The first coupling springs, as radial springs, extend radially from the axial groove at least in sections on the free end side, so that the first coupling springs center the stator in the motor housing during installation or insertion. In this case, the first radial coupling springs fix the stator tangentially (primarily) and axially (secondarily) in the housing. The second coupling spring fixes the stator axially (primarily) in the housing.

[0040] The spring element according to the invention can be adapted particularly flexibly to the respective stator or electric motor. Thus, due to the multifunctional spring element which can be variably configured in terms of development parameters, it can be adapted particularly optimally to the acoustic requirements of the electric motor. This means that the spring element can be adapted to the respective application, for example in terms of the width, number and material thickness of the coupling springs. BRIEF DESCRIPTION OF THE DRAWINGS

[0041] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0042] Figure 1 An electric motor with a motor housing and a bearing cover is shown in a perspective view;

[0043] Figure 2 The stator and rotor of the electric motor are shown in perspective view;

[0044] Figure 3 The electric motor is shown in a cross-sectional view;

[0045] Figure 4 The spring element of the stator is shown in a sectional view in section;

[0046] Figure 5 The spring element is shown in perspective view;

[0047] Figure 6 The spring element is shown in side view; and

[0048] Figure 7 The spring element is shown in a top view.

[0049] In all the figures, parts and variables that correspond to one another are always provided with the same reference symbols. DETAILED DESCRIPTION

[0050] Figure 1 The electric motor 2 shown has a motor housing 4 with a stator 6 and a rotor 8 arranged therein ( Figure 2). In this embodiment, the electric motor 2 is configured as an inner rotor. The rotor 8 is spliced ​​with the motor shaft 10 in a manner fixed relative to the shaft. The motor shaft 10 is supported in a rotatable manner by two bearings 12. The bearings 12 are implemented as ball bearings, for example. One of the bearings 12 is arranged in a bearing seat 13 of the housing bottom 14 of the motor housing 4, which is implemented as a (housing) intermediate wall. The other bearing 12 is arranged in a bearing cover 15, which is placed axially on the pot-shaped motor housing 4 as a cover at the end side opposite to the housing bottom 14.

[0051] exist Figure 2 and Figure 3 The stator 6 shown in detail in FIG. 1 has a stator base body 16. In the exemplary embodiment shown, the stator base body 16 is embodied with twelve stator teeth 17, which extend inwardly in the radial direction R (radial direction) in the direction of the central rotation axis D shown in the figure. Free spaces (not shown in detail) are formed between the stator teeth 17, in which windings of (stator) coils 18 are accommodated, which are connected to one another by means of end-side interconnecting rings 19, for example in a star circuit or a delta circuit, to form a stator winding or a rotating field winding. The coils 18 are arranged on an insulating coil body 20, which is placed on the stator teeth 17 ( Figure 3 ). The coil 18 and the coil body 20 are provided with reference numerals in the figures only by way of example. The interconnecting ring 19 is placed on the stator base body 16 at the end and is fastened in the axial groove 26 by means of locking tongues 21. The locking tongues 21 serve here as locating means or centering lugs.

[0052] The stator base body 16 has a stator yoke 22 or back iron which surrounds the stator teeth 17 on the circumference. In the exemplary embodiment shown, the stator base body 16 is designed in a so-called single-tooth design, wherein the stator 6 or its stator base body 16 consists of individual stator teeth 17. In an alternative exemplary embodiment not shown, the stator base body 16 is designed in a star-shaped yoke design, wherein the stator yoke 22 is a separate component and wherein the stator teeth 17 form a so-called stator star which is installed in the stator yoke 22. The stator 6 or the stator base body 16 or the stator teeth 17 are designed, for example, as a solid body or as a laminated core consisting of individual laminates.

[0053] Axial grooves 26 extending in the axial direction A and radially inwardly toward the axis of rotation D are introduced into the stator base body 16 on the outer circumference 24 of the stator yoke 22, i.e. on the outer circumference. The respective axial groove 26 is designed here in particular as a dovetail-shaped or T-shaped radial undercut of the outer circumference 24. The spring element 28 is seated radially in a form-fitting manner in the respective axial groove 26. The axial grooves 26 and the spring elements 28 are provided with reference numerals merely by way of example in the figures.

[0054] like Figures 4 to 7As shown, the spring element 28 has a strip-shaped or plate-shaped base body 30 , on which three first coupling springs or spring arms 32 and a second coupling spring 34 as well as three pairs of clamping jaws 36 are integrally formed.

[0055] The coupling spring or spring arm 32 is also referred to below as a radial spring, and the coupling spring 34 is referred to as an axial spring. The spring element 28 is in particular designed as a stamped bent part. The axial spring 34 is a spring-elastic (spring) tongue bent approximately in a C- or U-shape, which is arranged on the narrow side or end side of the substantially rectangular base body 30.

[0056] The spring-elastic radial springs 32 are formed from the base body 30 as stamped tongues and are bent out of the plane of the base body 30 in an approximately C-shaped or U-shaped manner. For this purpose, two of the radial springs 32 are arranged in the body of the base body 30, so that two window-like stamped openings or recesses 38 are formed in the base body 30. The third radial spring 32 is formed on the narrow side or end side of the base body 30 opposite the axial spring 34. The base body 30 protrudes beyond the radial springs 32 in the radial direction R and at least for the two stamped radial springs 32 inside the base body 30 in the axial direction A. The base body 30 therefore protrudes beyond the radial springs 32 on both sides in the circumferential direction or tangential direction T, which can be, for example, Figure 7 4. With the projections 40 on both sides, the spring element 28 undercuts the groove side formed by the dovetail shape or T-shape in the axial groove 26. The projections 40 are also referred to as connecting tabs or connecting tabs in the following. In other words, the groove side forms an undercut for the spring element 28 that is axially inserted into the axial groove 26.

[0057] As especially in Figure 6 As can be seen in the figure, the approximately U-shaped radial spring 32 is bent so that its horizontal U-shaped side has an acute inclination angle α relative to the base body 30. In the embodiment shown, the radial spring 32 has an inclination angle α of approximately 40°, ie, in particular 40°±5°. The characteristic curve of the radial spring 32, ie, the ratio between the spring force and the spring travel, is adjusted by the inclination angle α. In this case, the inclination angle α is preferably adapted to the respective application.

[0058] Here, the radial spring 32 or the angle of inclination α opens in the direction of the bearing cover 15. Thus, the spring element 28 in the side view ( Figure 6 ) has an approximately Christmas tree-shaped or sawtooth-shaped geometry. For installation, the stator 6 is inserted axially into the motor housing 4, wherein the radial springs 32 slide along the motor housing 4 with their free ends and are compressed in the direction of the rotation axis D or in the direction of the base body 30. The braced radial springs 32 thus also serve as an introduction aid for positioning the stator 6 in the motor housing 4.

[0059] On the base body 30 of the spring element 28 , outside the projection 40 , on the two long sides, three clamping jaws or clamping teeth 36 are each formed as a roughly triangular claw-like nose. The clamping jaws 36 are bent out of the plane of the base body 30 in the direction of the supported radial spring 32 .

[0060] Between the narrow side of the base body 30 and the axial spring 34, an approximately U-shaped bend 42 is provided, which bends first from the plane of the base body 30 in the direction of the radial spring 32 and then in the opposite direction, wherein a vertical U-shaped leg 44 of the bend 42 transitions into or passes into the approximately U-shaped bend of the axial spring 34. The U-shaped leg 44 forms a contact edge or a contact surface, which extends essentially from the plane of the base body 30 on the side of the base body 30 facing away from the radial spring 32 in the radial direction R. With this contact edge or contact surface 44, the spring element 28 (e.g., Figure 3 and especially in Figure 4 In the installed state, the stator base body 16 or its stator yoke 22 (as can be seen in FIG. 2 ) rests against the end face 46 of the stator base body 16 or its stator yoke 22 .

[0061] The axial spring 34 extends axially beyond the axial groove 6 and the end side 46 of the stator base body 16 in the installed state. The axial spring 34 is arranged in particular on the end side 46 of the stator base body 16 facing away from the interconnecting ring 19. The interconnecting ring 19 is arranged in particular facing the housing bottom 14 and the axial spring 34 is arranged facing the bearing cover 15.

[0062] Figure 3 and Figure 4 The electric motor 2 is shown in a sectional illustration in radial and axial section.

[0063] As especially Figure 3 As can be seen in FIG. 2 , the stator 6 rests against the inner wall 48 of the motor housing 4 via radial springs 32 of the spring elements 28, which are arranged radially and thus protrude beyond the stator 6 on the outer circumference 24 in the radial direction R. In particular, the radial springs 32 rest against the inner wall 48 in a sprung or articulated manner in the region of their free ends or outlets. In this way, the stator 6 is decoupled from the motor housing 4 of, for example, a 10-pole electric motor 2.

[0064] Furthermore, the stator 6 bears against the bearing cover 15 at the end via the axial spring 34 of the spring element 28 and is thus also decoupled from the bearing cover ( Figure 4). The axial spring 34 is supported on the end side 46 by means of a contact edge or a contact surface 44, and is compressed or bent relative to the bearing cover 15 at the edge of the spring installation space 50 on the free end side. This reduces the transmission of structure-borne noise caused by electromagnetic forces caused by operation to the motor housing 4 and the bearing cover 15, wherein the stator 6 is decoupled from the motor housing 4 and, if necessary, from the bearing cover 15 by means of the spring element 28. The spring element 28 preferably also has damping, fixing and / or positioning properties. In particular, the stator 6 is prevented from twisting in the motor housing 4 by the spring element 28 that is in contact with the inner wall 48 and the bearing cover 15.

[0065] The spring element 28 can be automatically and particularly easily inserted into the axial groove 26 in the axial direction A. Furthermore, the spring element 28 is held radially in a positively locking and thus secure manner in the axial groove 26. Furthermore, the spring element 28 is also secured as much as possible by the azimuthally supported and slightly radially bent clamping jaws 36. In particular, a positively locking and / or non-positively locking fixation in the tangential and axial directions of the axial groove 26 is achieved here.

[0066] The present invention is not limited to the above-mentioned embodiments. On the contrary, those skilled in the art can also derive other key points of the present invention therefrom without departing from the subject matter of the present invention. In addition, in particular, the individual features described in conjunction with the embodiments can also be combined with each other in other ways without departing from the subject matter.

[0067] The electric motor 2 shown in the exemplary embodiment is in particular a steering motor for a motor vehicle. The above-described solution can be used not only for the specifically shown application, but also in a similar embodiment for other motor vehicle applications, such as electric brake motors, door and tailgate systems, window lifters and electric drives and their arrangement in the vehicle or other electric machines and systems.

[0068] Reference numerals list

[0069] 2 Electric motor

[0070] 4 Motor housing

[0071] 6 Stator

[0072] 8 Rotor

[0073] 10 Motor shaft

[0074] 12 Bearings

[0075] 13 Bearing seat

[0076] 14 Shell bottom

[0077] 15 Bearing cap

[0078] 16 Stator base

[0079] 17 stator teeth

[0080] 18 Coil

[0081] 20 Coil body

[0082] 21 Lock tongue

[0083] 22 Stator yoke

[0084] 24 Periphery

[0085] 26 Axial groove

[0086] 28 Spring element

[0087] 30 Matrix

[0088] 32 Coupling spring / radial spring

[0089] 34 Coupling spring / axial spring

[0090] 36 jaws

[0091] 38 blank space

[0092] 40 protrusion

[0093] 42 Bend

[0094] 44 U-shaped edge / contact edge / contact surface

[0095] 46 End side

[0096] 48 Inner wall

[0097] 50 Spring installation space

[0098] A Axial direction

[0099] R Radial direction

[0100] T Tangential direction

[0101] D Rotation axis

Claims

1. A stator (6) for an electric motor (2), comprising a stator base body (16) with stator teeth (17) arranged in a star shape and a stator yoke (22), wherein: A number of axial grooves (26) are arranged on the outer circumference (24) of a stator base body (16), in which spring elements (28) protruding radially on the circumference of the stator base body (16) are arranged in a radially positively locked manner, wherein the spring element (28) has a base body (30) and at least one first coupling spring (32) which is tilted in a radial direction (R) and protrudes from the axial groove (26), and wherein the spring element (28) has at least one clamping claw (36) on the longitudinal side of the base body (30) for tangential fastening in the axial groove (26).

2. The stator (6) according to claim 1, characterized in that The respective axial groove (26) is designed as a radial undercut of the outer circumference (24).

3. The stator (6) according to claim 1, characterized in that The spring element (28) has, on a narrow side of the base body (30), a second coupling spring (34) which protrudes axially from the axial groove (26).

4. The stator (6) according to claim 3, characterized in that The spring element (28) has a contact edge or a contact surface (44) in the region of the second coupling spring (34), with which the spring element (28) rests against an end face (46) of the stator base body (16).

5. The stator (6) according to claim 1, characterized in that The respective clamping jaw (36) is bent out from the plane of the base body (30).

6. The stator (6) according to claim 1, characterized in that The spring element (28) is designed as a one-piece stamped and bent part.

7. An electric motor (2), comprising a motor shaft (10), a rotor (8) fixed relative to the shaft, a stator (6) according to any one of claims 1 to 6, and a motor housing (4), wherein the stator (6) is arranged in the motor housing with a spring element (28) which is inserted into an axial groove (26) on the outer circumference and is held therein in a radially positive locking manner.

8. The electric motor (2) according to claim 7, characterized in that The spring element (28) is axially seated in the axial groove (26).

9. A spring element (28) for placement in an axial groove (26) of a stator (6), the spring element having a base body (30) having: at least one first coupling spring (32), which is introduced into the base body (30) as a stamped tongue and is bent out of the plane of the base body (30), and a second coupling spring (34), which is arranged on a narrow side of the base body (30), in, The at least one first coupling spring (32) is tilted in the radial direction (R) and protrudes from the axial groove (26), and the spring element (28) has at least one clamping claw (36) on the longitudinal side of the base body (30) for tangential fastening in the axial groove (26).

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