Electric motor

Abstract

The invention relates to an electric motor, having a rotor shaft, a floating bearing and an end shield, wherein: the floating bearing is provided for rotatably mounting the rotor shaft; the floating bearing has an inner ring and an outer ring; the outer ring of the floating bearing is received in a bearing seat formed in the end shield; the inner ring is fitted onto the rotor shaft; the bearing seat is interrupted in places by slots; and the slots are mutually interspaced in the circumferential direction.

Description

[0001] electric motor

[0002] Description:

[0003] The invention relates to an electric motor.

[0004] It is generally known that at least two bearings, in particular rolling bearings, are used to support a shaft.

[0005] From DE 10 2008 028 607 A1, an electric motor is known as the closest state of the art.

[0006] A floating bearing arrangement is known from DE 10 2021 205 788 A1.

[0007] An electric motor is known from DE 20 2007 009 954 U1.

[0008] An electric motor is known from DE 10 2011 119 603 A1.

[0009] A torsional vibration damper with friction coefficient adjustment is known from DE 10 2020 120 389 A1.

[0010] From DE 10 2020 006 831 A1 an electric motor with a fan cover and a rotor shaft mounted so that it can rotate relative to the fan cover and an angle sensor is known.

[0011] From DE 10 2019207 290 A1 a friction brake body for a friction brake of a motor vehicle is known.

[0012] EP 1 711 642 B1 discloses an iron-containing layer of a sliding surface applied by thermal spraying.

[0013] A regulated powder deposition welding process is known from DE 10 2018 130 798 A1.

[0014] A bearing device is known from DE 10 2016 223 009 A1. The invention is therefore based on the object of developing an electric motor, whereby the operation of the electric motor is to be carried out as safely as possible.

[0015] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0016] Important features of the invention in the electric motor are that the electric motor has a rotor shaft, a movable bearing and a bearing shield, wherein the movable bearing is provided for the rotatable mounting of the rotor shaft, wherein the movable bearing has an inner ring and an outer ring, in particular wherein rolling elements are arranged between the inner ring and the outer ring, wherein the outer ring of the movable bearing is received in a bearing receptacle formed, in particular molded, in the bearing shield, in particular a cup-shaped bearing receptacle and / or blind hole, wherein the inner ring is placed onto the rotor shaft, wherein the bearing receptacle is interrupted by slots, wherein the slots are spaced apart from one another, in particular regularly, in the circumferential direction, in particular wherein the circumferential direction is related to the axis of rotation of the rotor shaft.

[0017] According to the invention, the bearing holder of the floating bearing is designed with slots.

[0018] The advantage here is that the bearing mount has greater elasticity, allowing the outer ring of the floating bearing to be accommodated in the bearing mount with such a transition fit that it prevents the outer ring from spinning or rotating along with the bearing while still allowing for low static friction during axial displacement of the outer ring. This prevents the outer ring from rotating and allows for axial displacement with minimal force.

[0019] The invention therefore has the advantage of ensuring safe operation because the outer ring of the floating bearing is prevented from rotating or slipping. On the one hand, the outer ring of the floating bearing is arranged so that it can be axially displaced, so that thermally induced axial length changes of the rotor shaft are tolerable. On the other hand, rotation in the circumferential direction of the outer ring is prevented by the rotationally fixed connection of the outer ring to the bearing mount of the bearing shield.

[0020] In an advantageous embodiment, the bearing shield comprises a base body and the bearing support, which has claw regions connected to the base body, particularly at their root regions. Advantageously, the claw regions protrude axially from the base body, allowing the bearing support to be thin-walled and with slots interrupting the bearing support. This allows for increased elasticity and thus a corresponding transition fit, enabling the outer ring to be displaced axially with minimal force.

[0021] In an advantageous embodiment, the base body is formed integrally with the claw areas, particularly as a single piece, particularly as a cast part. This is advantageous because it allows for simple manufacturing.

[0022] In an advantageous embodiment, the claw regions are spaced apart from one another in the circumferential direction by means of the slots. This is advantageous in that the elasticity of the claw regions is increased. In particular, the deflection of the respective claw region in the radial direction is facilitated, thus, in particular, the elasticity at the respective circumferential angular position is increased.

[0023] In an advantageous embodiment, the bearing mount has a conical shape on its inner side. The advantage here is that the pressure acting on the radial outer circumference of the outer ring of the floating bearing does not change when the floating bearing is axially displaced, particularly as long as this displacement remains below a critical amount. If the outer ring is positioned closer to the base body of the bearing shield, i.e., deeper in the bearing mount, the amount of deflection in the claw area is smaller. However, due to the conical shape and the resulting greater expansion when the outer ring is positioned deeper, the radial distance between the outer ring of the floating bearing and the inner side of the respective claw area and / or the bearing mount remains constant.For this purpose, however, the cone angle of the conical shape must be dimensioned appropriately, in particular in such a way that the pressure of the bearing seat on the radial outer circumference of the outer ring of the floating bearing is independent of the axial depth of the outer ring in the bearing seat.

[0024] In an advantageous embodiment, the inside diameter of the bearing mount increases with decreasing distance from the base body of the bearing shield in the axial direction. The advantage here is that the pressure acting on the radial outer circumference of the outer ring of the floating bearing does not change when the floating bearing is axially displaced, particularly as long as this displacement remains below a critical amount. This is because if the outer ring is positioned closer to the base body of the bearing shield, i.e. deeper in the bearing mount, the amount of deflection in the claw area is smaller, but due to the increase in the inside diameter, the radial distance between the outer ring of the floating bearing and the inside of the respective claw area and / or the bearing mount remains constant when the outer ring is positioned deeper.Preferably, the increase in the clear diameter is such that the pressure of the bearing seat on the radial outer circumference of the outer ring of the loose bearing is independent of the axial depth of the outer ring in the bearing seat.

[0025] The radial direction and the circumferential direction are always related to the axis of rotation of the rotor shaft; the axial direction is aligned parallel to the axis of rotation of the rotor shaft.

[0026] In an advantageous design, the slots extend radially through the bearing mount. This is advantageous because the claw areas can be elastically deflected independently of one another, thus enabling optimized adaptation to the outer ring. Additionally, transverse forces acting on the rotor shaft can be optimally distributed and dissipated around the circumference.

[0027] In an advantageous embodiment, a spring washer is arranged in the axial direction between the outer ring and the bearing plate, in particular the bottom of the bearing receptacle, wherein the spring washer has a coating at least on first and second surface areas or is roughened by sandblasting or laser-structured, in particular with elevations that extend further in the radial direction than in the circumferential direction.

[0028] The advantage here is that safe operation is possible because the outer ring of the floating bearing is prevented from rotating or slipping. On the one hand, the outer ring of the floating bearing is arranged so that it can be moved axially, so that thermally induced axial changes in length of the shaft are tolerable, but on the other hand, rotation in the circumferential direction for the outer ring is prevented by the outer ring being rotationally fixedly connected to the bearing mount of the bearing shield. The spring washer is axially deflected by the thermally induced axial changes in length, but the outer ring is prevented from rotating in the circumferential direction by the spring washer. This is achieved by the increased adhesion or friction that can be brought about by the coatings, especially in comparison to an uncoated spring washer made of sheet steel and held in the steel bearing mount, whereby the outer ring is also made of steel.Thus, even a simple rubber coating of the spring washer can achieve high adhesion between the spring washer and the bearing plate, as well as between the spring washer and the outer ring. However, if adhesive is used as a coating at the contact points between the spring washer and the bearing plate, as well as between the spring washer and the outer ring, a particularly torsion-resistant connection can be achieved, thus preventing the outer ring from slipping or rotating.

[0029] In particular, the first surface areas are spaced apart from one another in the circumferential direction, and the second surface areas are spaced apart from one another in the circumferential direction. The first surface areas are arranged in the axial direction on the front side of the spring washer, and the second surface areas are arranged in the axial direction on the rear side of the spring washer. The advantage here is that

[0030] In particular, the spring washer can also be referred to as a spring wave washer, as the spring washer is designed as an annular perforated washer whose edge area runs in a wave-like manner in the circumferential direction in the axial direction. As the circumferential angle increases, the axial position of the spring washer fluctuates. This means that the axial position of the spring washer is a periodic function of the circumferential angle. Instead of coating, the surface can also be roughened, particularly by sandblasting or laser structuring. In the latter case, it is advantageous to create elongated structures in the microscale in the radial direction so that the static friction prevents the spring washer or the outer ring of the floating bearing from rotating as effectively as possible.

[0031] In an advantageous design, the spring washer rests against both the bearing plate, particularly the base of the bearing housing, and the outer ring. This provides increased grip and thus anti-twist protection.

[0032] In an advantageous embodiment, the axial position of the spring washer, in particular the axial position of the mean value of the area covered by the spring washer in the axial direction, is a periodic, in particular non-vanishing, function of the circumferential angular position. Advantageously, the spring washer periodically oscillates back and forth in the circumferential direction as the circumferential angle increases in the axial direction. Thus, the installation of the spring washer between the outer ring and the bearing mount causes an elastic deflection of the spring washer, which thus sets or generates the bearing tension. The ring axis, in particular the central axis of the spring washer, is aligned parallel to the axial direction.

[0033] In an advantageous embodiment, the outer ring is accommodated in the bearing mount with an interference fit. The advantage here is that in the event of thermally induced length changes of the rotor shaft, the floating bearing, in particular the outer ring of the floating bearing, can be moved in the axial direction. It is important that the static friction is kept correspondingly low. This can be achieved by designing the bearing mount with a sufficiently widened design so that the outer ring can be accommodated with a transition fit, with the transition fit being tolerated in such a way that the floating bearing can be moved axially in the event of thermally induced length changes. However, in order to prevent the outer ring from rotating in the circumferential direction relative to the axis of rotation of the rotor shaft with this widened bearing mount, the coatings of the spring washer are selected such that the outer ring is connected in a rotationally fixed manner to the bearing shield via the spring washer, particularly in the bearing mount.

[0034] In an advantageous embodiment, the outer ring is so precisely fitted in the

[0035] Bearing mount that the static friction moment which is in

[0036] The static friction moment generated by the operative connection of the outer ring accommodated in the bearing support with the bearing shield is smaller than any static friction moment generated by the operative connection of the spring washer with the outer ring and than any static friction moment generated by the operative connection of the spring washer with the bearing shield. The advantage here is that, on the one hand, a rotationally fixed, materially connected and / or force-fit connection between the outer ring and the bearing shield is achieved by means of the spring washer, but, on the other hand, axial displacement of the floating bearing is possible without force or with only minimal force.

[0037] In an advantageous embodiment, the coating is an adhesive, a rubber coating, and / or a plastic layer. This is advantageous because a force-fitting and / or material-fitting, rotationally fixed connection between the outer ring and the bearing plate can be achieved by means of the spring washer. A carbide layer is preferably used as the coating.

[0038] In an advantageous embodiment, the coating has a metallic layer. This ensures a long service life of the coating.

[0039] In particular, the coating comprises a carbide layer, in particular a metal-carbide layer, in particular wherein this carbide layer is applied to a surface of the spring washer that is roughened in particular by means of a laser and / or wherein the carbide layer is applied to the spring washer by means of a high-speed laser deposition welding process (HS-LMD).

[0040] In an advantageous embodiment, the first surface areas coated are those areas of the spring washer that are the farthest from the outer ring. This is advantageous because only minimal material expenditure is required, since only the contact areas between the spring washer and the outer ring and between the spring washer and the bearing plate need to be coated.

[0041] In an advantageous embodiment, the second surface areas coated are those areas of the spring washer that are closest to the outer ring, in particular those that contact the outer ring. This is advantageous because only minimal material expenditure is required, since only the contact areas between the spring washer and the outer ring and between the spring washer and the bearing plate need to be coated.

[0042] In an advantageous embodiment, the spring washer is made of a steel sheet to which the coatings are applied. This is advantageous because it provides a high modulus of elasticity. This allows the spring washer to be manufactured cost-effectively and generates a high spring force even with a small axial deflection.

[0043] In an advantageous embodiment, the outer ring is arranged so that it can move axially, particularly in the bearing housing, and / or the outer ring is connected to the bearing plate in a rotationally fixed manner by means of the spring washer. This advantageously allows the floating bearing to be axially displaceable in the event of thermally induced changes in the length of the rotor shaft, even though it is connected to the bearing plate in a rotationally fixed manner, particularly by a material and / or force-locking connection.

[0044] In an advantageous design, the spring washer contacts both the outer ring and the bearing plate. This is advantageous because the spring washer provides the bearing tension, and the coating also ensures a rotationally fixed connection between the outer ring and the bearing plate.

[0045] In an advantageous embodiment, the bearing shield is connected to a stator housing of the electric motor, wherein a bearing flange is connected to the stator housing on the side of the stator housing axially facing away from the bearing shield, wherein an outer ring of a fixed bearing is received in the bearing flange, the inner ring of which is placed on the rotor shaft, in particular wherein the inner ring of the fixed bearing is positioned against a shaft step and is axially delimited by a retaining ring which is arranged in an annular groove of the rotor shaft, in particular wherein the outer ring of the fixed bearing axially bears on the one hand against the base of the bearing receptacle of the bearing flange and axially on the other hand is positioned against a retaining ring arranged in an annular groove of the bearing flange. The advantage here is that the stator housing causes thermally induced length changes, in particular in the axial direction, by means of power loss of the stator winding.Depending on the material and geometry, these can vary depending on the length change of the rotor shaft. To compensate, the floating bearing is arranged so that it can be moved axially.

[0046] In an advantageous embodiment, the rotor shaft extends through a recess in the bearing plate, and a fan is connected to the rotor shaft in a rotationally fixed manner on the side of the bearing plate axially remote from the floating bearing. To seal the recess, a shaft seal is accommodated in the bearing plate, in particular in the recess of the bearing plate, and seals against the rotor shaft, in particular by a sealing lip of the shaft seal contacting the rotor shaft. This is advantageous because the bearing plate can be cooled by the air flow conveyed by the fan, thus reducing length changes.

[0047] In an advantageous embodiment, the rotor shaft protrudes through a bore extending through the bearing flange, with an additional shaft seal being accommodated in the bore on the side of the fixed bearing axially remote from the floating bearing and sealing against the rotor shaft, in particular by a sealing lip of the additional shaft seal contacting the rotor shaft. The advantage here is that the shaft seal accommodated in the bearing shield and the shaft seal accommodated in the bearing flange together seal the interior of the electric motor from the environment, thus preventing dirt or dust from penetrating the bearing mount, which could impede or prevent the floating bearing from moving.

[0048] In an advantageous embodiment, a stator core with a stator winding is housed in the stator housing, and a squirrel cage is mounted on the rotor shaft and connected in a rotationally fixed manner. This is advantageous because the stator housing and the rotor shaft can be exposed to varying degrees of heat loss depending on the operating state of the motor. The resulting length changes can be compensated for by the spring washer according to the invention.

[0049] Further advantages emerge from the dependent claims. The invention is not limited to the combination of features in the claims. Further possible combinations of claims and / or individual claim features and / or features of the description and / or the figures will become apparent to those skilled in the art, particularly from the problem and / or the problem posed by comparison with the prior art.

[0050] The invention will now be explained in more detail using schematic illustrations:

[0051] Figure 1 shows an electric motor according to the invention in a sectional view.

[0052] Figure 2 shows an exploded oblique view of a bearing plate 3 with a spring washer 2 and a loose bearing 1 of the electric motor.

[0053] Figure 3 shows an oblique view of the spring washer 2.

[0054] Figure 4 shows a side view of the spring washer 2.

[0055] In Figure 5, a bearing plate 51 according to the invention is shown exploded in an oblique view.

[0056] As shown in the figures, the electric motor has a stator housing 9, which is connected at its first axial end region to a bearing plate 3 and at its other axial end region to a bearing flange 8. The stator housing 9 is thus arranged axially between the bearing flange 8 and the bearing plate 3.

[0057] A fixed bearing 7 is housed in the bearing shield 3, the inner ring of which is mounted on a rotor shaft 4 of the electric motor and positioned against a shaft stage of the rotor shaft 4. The outer ring of the fixed bearing 7 is housed in a bearing recess formed on the bearing flange 8 and is axially limited by a retaining ring arranged in an annular groove of the bearing flange 8. A further retaining ring arranged in an annular groove of the rotor shaft 4 limits the inner ring of the fixed bearing. The fixed bearing is thus axially fixed. Thermally induced expansion of the rotor shaft 4 must therefore be compensated by a floating bearing 1.

[0058] The outer ring of the floating bearing 1 is accommodated in the bearing shield 3. The inner ring of the floating bearing 1 is placed on the rotor shaft 4 and, on its side facing the fixed bearing, is positioned against a shaft step formed on the rotor shaft 4. A spring washer 2 is arranged on the side of the floating bearing 1 facing away from the fixed bearing 7. In particular, the spring washer 2 is arranged axially between the bottom of the bearing housing and the outer ring of the floating bearing 1.

[0059] The spring washer 2, in particular a wave washer or even an elastically deformable and / or resilient wave washer, is designed as an annular perforated washer whose ring axis is aligned coaxially with the rotational axis of the rotor shaft 4 and whose edge region extends in a wave-like manner in the circumferential direction, in particular with the wave amplitude varying in the axial direction. In particular, the wave amplitude or the axial position of the spring washer 2 fluctuates with increasing circumferential angle. This means, in particular, that the axial position of the spring washer 2 is a periodic function of the circumferential angle.

[0060] When installed in the electric motor, the spring washer 2 generates the bearing tension and is elastically deformed, in particular pre-tensioned.

[0061] For this purpose, the spring washer 2 is produced as a deformed stamped sheet metal part, in particular as an annular sheet steel body, in particular wherein the perforated disc punched from sheet metal is bent in such a wavy manner as a bent part that, with reference to the axis of rotation of the rotor shaft 4, the axial position of the spring washer 2 is a periodic function as a function of the circumferential angular position. The period length in the circumferential direction is preferably 360° / N, where N is a natural number, in particular greater than two. The spring washer therefore has N maxima in the axial direction and N minima in the axial direction on the circumference, in particular wherein the maxima press against the outer ring of the loose bearing 1 in an elastically preloaded manner and touch this, and wherein the minima press against the bearing plate 3 in an elastically preloaded manner and touch this.

[0062] The axis of rotation of the rotor shaft 4 is thus aligned coaxially with the ring axis of the spring washer 2, which is designed as a wavy perforated disc.

[0063] The sheet thickness, in particular the wall thickness, of the spring washer 2 is constant throughout. At those points on the spring washer 2 that are at the greatest distance from the outer ring of the floating bearing 1, particularly at the minimum points, the spring washer 2 has adhesive 30 on its side facing away from the floating bearing 1.

[0064] At those points of the spring washer 2 which have the smallest distance to the outer ring of the floating bearing 1, in particular at the maxima, the spring washer 2 has adhesive 40 on its side facing the floating bearing 1.

[0065] In this way, a material connection is created between the spring washer 2 and the outer ring of the floating bearing 1 and between the spring washer 2 and the bearing plate 3. This prevents the spring washer 2 from rotating or the outer ring of the floating bearing 1 from rotating.

[0066] In this case, the bearing mount is also designed with a transition fit, so that the outer ring is accommodated in the bearing mount with only minimal static friction. This allows for axial displacement of the outer ring of the floating bearing 1 during thermal expansion of the rotor shaft 4 without the outer ring being dragged along. This is because, although the elastic preload changes during axial displacement, bearing tension is still provided by the spring washer 2.

[0067] The static friction torque, which is provided by means of the transition fit in the bearing seat for the outer ring of the floating bearing 1 to prevent co-rotation in the circumferential direction, is smaller than the critical torque, at the exceedance of which the adhesive connection between the spring washer 2 and the bearing plate 3 and / or the adhesive connection between the spring washer 2 and the outer ring of the floating bearing 1 fails.

[0068] A fan 5 is non-rotatably connected to the rotor shaft 4 on the side of the bearing plate 3 axially facing away from the fixed bearing 7. This enables efficient passive cooling.

[0069] A fan cover 6 surrounds the fan 5 and is connected to the bearing plate 3.

[0070] A stator 10, in particular a stator core with a stator winding, is accommodated in the stator housing 9. Figure 5 shows an exploded oblique view of an inventive bearing plate 51, on which the cup-shaped bearing receptacle for the floating bearing 1 has slots 50, in particular axially directed slots 50, spaced at regular intervals from one another in the circumferential direction.

[0071] The bearing holder protrudes axially from the bearing plate 51, in particular on the side of the bearing plate 51 facing the fixed bearing 7, and is - as in the embodiment according to Figures 1 to 4 - designed in one piece with the rest of the bearing plate 51, in particular in one part.

[0072] The lateral wall, in particular the cup wall of the cup-shaped bearing mount, essentially resembles a hollow cylinder, although the axially directed slots 50 are incorporated and the inside of the hollow cylinder has a conical shape. The cone tip points towards the fixed bearing 7. The inside diameter of the bearing mount therefore increases with increasing distance from the fixed bearing 7. This ensures that the pressure is independent of the joining depth of the outer ring of the floating bearing 1 in the axial direction. Thus, if the outer ring is displaced further away from the fixed bearing 7 in the axial direction, the pressure on the outer ring, in particular from the bearing shield onto the radial outer circumference of the outer ring, remains essentially the same.

[0073] By means of the slots 50, the bearing mount consists of claw regions that are spaced apart from one another in the circumferential direction. At their axial end regions, the claw regions transition into the rest of the bearing plate 3, in particular the base body, whereby these transition regions are referred to as the root region.

[0074] The base body is designed like a perforated disc, with the rotor shaft 4 protruding through the hole of the perforated disc.

[0075] The clear diameter of the bearing seat therefore increases in the axial direction with decreasing distance to the root areas.

[0076] The cone angle of the conical shape of the bearing support of the movable bearing 1 is preferably so small that the clear diameter per centimeter in the axial direction increases by less than two tenths, in particular less than two hundredths, of a millimeter with increasing distance from the fixed bearing 7.

[0077] The number of slots 50 is preferably three or a larger natural number, preferably an odd number. The maximum extension of each slot 50 is less than 3607 N, where N is the number of slots around the circumference of the bearing support. Preferably, the number N is an odd number.

[0078] The base body and the claw areas including their root areas are formed in one piece, in particular as a single piece, in particular as a cast part.

[0079] The rotor shaft is therefore rotatably supported via the loose bearing 1 and the fixed bearing 7.

[0080] In further embodiments of the invention, in a bearing receptacle designed with slots 50, the spring washer 2 according to the embodiment shown in Figures 1 to 5 is additionally interposed between the outer ring of the floating bearing 1 and the bearing plate 3. Thus, the coating again creates a rotationally fixed connection between the outer ring and the bearing plate by means of the spring washer 2.

[0081] By means of the only low pressure due to the elastically deflectable slots 50 and in particular also the pressure which is always the same regardless of the axial position of the outer ring, rotation of the outer ring is prevented and nevertheless a thermally induced axial displacement of the outer ring is possible.

[0082] In further embodiments according to the invention, the slots 50 are rounded at their end region facing away from the fixed bearing 7. Thus, the slots 50 extend into the respective root regions with a rounded end region. This allows for increased fracture resistance.

[0083] In further embodiments according to the invention, a rubber coating or another coating is used instead of the adhesive, which generates sufficient static friction in operative connection with the material of the bearing plate or with the material of the outer ring of the floating bearing 1.

[0084] The static friction torque, which is provided by means of the transition fit in the bearing holder for the outer ring of the floating bearing 1 to prevent co-rotation in the circumferential direction, is smaller than the maximum static friction torque that can be provided by the friction partners, i.e. spring washer 2, bearing plate 3 and / or outer ring of the floating bearing 1, in particular in the circumferential direction.

[0085] In further embodiments of the invention, a carbide layer applied by means of HS-LMD is used instead of the adhesive.

[0086] In further embodiments according to the invention, the surface is roughened instead of the coating or adhesive. Either sandblasting or laser structuring can be used for this. While sandblasting can be carried out cost-effectively, laser structuring also enables the creation of depressions and elevations that extend further in the radial direction than in the circumferential direction, instead of isotropic elevations in the micro range to increase static friction. Since the depressions and elevations created by the laser extend further in the radial direction than in the circumferential direction, a high static friction moment can be generated, i.e., a relative rotational movement of the spring washer 2 relative to the respective friction partner, in particular the bearing plate 3 or the outer ring of the floating bearing 1.

[0087] In further development, one of the above-mentioned coatings can be applied to the roughened surface.

[0088] List of reference symbols

[0089] 1 Floating bearing 2 Spring washer

[0090] 3 bearing plate

[0091] 4 Rotor shaft

[0092] 5 fans

[0093] 6 Fan cover 7 Fixed bearing

[0094] 8 Bearing flange

[0095] 9 Stator housing

[0096] 10 Stator, in particular stator core with stator winding

[0097] 30 Adhesive 40 Adhesive

[0098] 50 slot

[0099] 51 Bearing shield

Claims

Patent claims:

1. Electric motor, comprising a rotor shaft, a movable bearing and a bearing shield, wherein the movable bearing is provided for the rotatable mounting of the rotor shaft, wherein the movable bearing has an inner ring and an outer ring, in particular wherein rolling elements are arranged between the inner ring and the outer ring, wherein the outer ring of the movable bearing is received in a bearing receptacle formed in the bearing shield, in particular shaped, in particular a cup-shaped bearing receptacle and / or designed as a blind hole, wherein the inner ring is placed on the rotor shaft, characterized in that the bearing receptacle is designed to be interrupted by slots, wherein the slots are spaced apart from one another, in particular regularly, in the circumferential direction, in particular wherein the circumferential direction is related to the axis of rotation of the rotor shaft.

2. Electric motor according to claim 1, characterized in that the bearing plate has a base body and the bearing receptacle, which has claw regions which are connected to the base body, in particular at their root regions.

3. Electric motor according to one of the preceding claims, characterized in that the base body is formed integrally with the claw regions, in particular in one piece, in particular as a cast part.

4. Electric motor according to one of the preceding claims, characterized in that the claw regions are spaced from one another in the circumferential direction by means of the slots.

5. Electric motor according to one of the preceding claims, characterized in that the bearing holder is conically shaped on its inner side, the inside diameter of the bearing holder increasing with decreasing distance from the base body of the bearing shield in the axial direction.

6. Electric motor according to one of the preceding claims, characterized in that the slots pass through the bearing holder in the radial direction.

7. Electric motor according to one of the preceding claims, characterized in that a spring washer, in particular a resilient wave washer, is arranged in the axial direction between the outer ring and the bearing plate, in particular the base of the bearing receptacle, wherein the spring washer has a coating at least on first and second surface regions or is roughened by sandblasting or laser-structured, in particular with elevations that extend further in the radial direction than in the circumferential direction, in particular wherein the first surface regions are spaced apart from one another in the circumferential direction and wherein the second surface regions are spaced apart from one another in the circumferential direction.

8. Electric motor according to one of the preceding claims, characterized in that the spring washer rests both on the bearing plate, in particular on the bottom of the bearing holder, and on the outer ring.

9. Electric motor according to one of the preceding claims, characterized in that the axial position of the spring washer, in particular the axial position of the mean value of the area covered by the spring washer in the axial direction, is a periodic, in particular non-vanishing, function of the circumferential angular position, and / or that the outer ring is received in the bearing receptacle with an overfit, and / or that the outer ring is received in the bearing receptacle with such a precise fit that the static friction moment generated in the operative connection of the outer ring received in the bearing receptacle with the bearing plate is smaller than the static friction moment generated by the operative connection of the spring washer with the outer ring and than the static friction moment generated by the operative connection of the spring washer with the bearing plate, and / or that the coating is an adhesive, a rubber coating and / or a plastic layer,or that the coating comprises a metallic layer or that the coating comprises a carbide layer, in particular wherein the carbide layer is applied to a surface of the spring washer that is roughened in particular by means of a laser and / or wherein the carbide layer is applied to the spring washer by means of a high-speed laser deposition welding process (HS-LMD).

10. Electric motor according to one of the preceding claims, characterized in that the first surface areas provided with the coating are those areas of the spring washer which have the greatest distance from the outer ring.

11. Electric motor according to one of the preceding claims, characterized in that the second surface areas provided with the coating are those areas of the spring washer which have the smallest distance from the outer ring, in particular which touch the outer ring, and / or that the spring washer is made of a steel sheet to which the coatings are applied.

12. Electric motor according to one of the preceding claims, characterized in that the outer ring is arranged to be displaceable in the axial direction, in particular in the bearing receptacle, and / or that the outer ring is connected to the bearing plate in a rotationally fixed manner by means of the spring washer, and / or that the spring washer contacts both the outer ring and the bearing plate.

13. Electric motor according to one of the preceding claims, characterized in that the bearing shield is connected to a stator housing of the electric motor, wherein on the side of the stator housing axially facing away from the bearing shield, a bearing flange is connected to the stator housing, wherein an outer ring of a fixed bearing is received in the bearing flange, the inner ring of which is placed on the rotor shaft, in particular wherein the inner ring of the fixed bearing is positioned against a shaft step and is axially delimited by a retaining ring which is arranged in an annular groove of the rotor shaft, in particular wherein the outer ring of the fixed bearing axially bears on the one hand against the base of the bearing receptacle of the bearing flange and axially on the other hand is positioned against a retaining ring arranged in an annular groove of the bearing flange.

14. Electric motor according to one of the preceding claims, characterized in that the rotor shaft projects through a recess in the bearing plate and a fan is connected in a rotationally fixed manner to the rotor shaft on the side of the bearing plate axially remote from the floating bearing, wherein, for sealing the recess, a shaft sealing ring is accommodated in the bearing plate, in particular in the recess of the bearing plate, and seals towards the rotor shaft, in particular in that a sealing lip of the shaft sealing ring touches the rotor shaft.

15. Electric motor according to one of the preceding claims, characterized in that the rotor shaft projects through a bore through the bearing flange, wherein a further shaft sealing ring is accommodated in the bore on the side of the fixed bearing axially facing away from the movable bearing and seals off the rotor shaft, in particular in that a sealing lip of the further shaft sealing ring touches the rotor shaft, and / or that a stator laminated core with stator winding is accommodated in the stator housing and a squirrel cage is placed on the rotor shaft and connected in a rotationally fixed manner.

Images