Electric motor with a connection box

Abstract

The invention relates to a drive, in particular an electric motor, comprising a connection box. A stator housing part of the drive is connected to a first bearing shield on which a bearing receiving area for a first bearing is formed in order to rotatably support the rotor shaft, and the bearing shield is equipped with a lower part, in particular a trough-shaped lower part, on which a cover part of the drive is placed, said cover part being connected to the lower part in particular. A stator laminated core is received in the stator housing part, a stator winding made of a winding wire being arranged in said stator laminated core, and the ends of the winding wire are guided to a wiring unit, to which a mating plug connector part is connected that is plugged to a plug connector part, said plug connector part being part of a power electronics system which is arranged within the connection box.

Description

[0001] ELECTRIC MOTOR WITH A JUNCTION BOX

[0002] Description:

[0003] The invention relates to a drive, in particular an electric motor, with a terminal box.

[0004] It is generally known that a drive is electrically powered and therefore requires connections for supply lines. These connections can be arranged in a terminal box.

[0005] The closest prior art known from AT 518 125 A1 is a housing cover for an electrical machine.

[0006] An electric motor is known from DE 20 2007 019 072 U1.

[0007] A brake is known from DE 10 2010 049 744 A1.

[0008] The invention is therefore based on the object of developing a drive that can be produced efficiently.

[0009] According to the invention, the object is achieved by the drive according to the features specified in claim 1.

[0010] Important features of the invention in the drive, in particular electric motor, with a terminal box are that a stator housing part of the drive is connected to a first bearing plate on which a bearing receptacle for a first bearing for the rotatable mounting of the rotor shaft is formed, wherein a lower part, in particular a trough-shaped lower part, is formed on the bearing plate, onto which a cover part of the drive is placed, in particular and connected to the lower part, wherein a stator laminated core is accommodated in the stator housing part, in which a stator winding formed from winding wire is arranged, wherein the ends of the winding wire are led to a wiring unit to which a mating connector part is connected, which is plug-connected to a plug-in connector part, which is comprised of power electronics arranged within the terminal box.

[0011] The advantage here is that the plug connection protrudes through a recess in the bearing shield. This means that the connector part is secured within the terminal box and connected to the mating connector located inside the stator. When the electronics are mounted, the plug connection is inserted. The plug connection protrudes through the collar area formed on the bearing shield, which protrudes axially and runs particularly circumferentially around the rotational axis of the rotor shaft.

[0012] The connector is arranged in the stator on a connection unit so that the stator winding, which is connected in a star or delta configuration, can be supplied directly from the power electronics via the connector. This module comprises a power module with power semiconductors arranged in parallel-connected half-bridges. This parallel connection acts as an inverter and is supplied from a DC voltage source, which can preferably be implemented as a mains-fed rectifier. Each half-bridge is designed as a series connection of two power semiconductor switches, in particular IGBTs or MOSFETs, with the respective center tap of the respective series connection being electrically connected to a respective phase of the stator winding.

[0013] The control signals for the power semiconductor switches are generated by the signal electronics.

[0014] The signal electronics can therefore be implemented together with the power electronics as a converter or inverter.

[0015] The axial direction is always to be understood as parallel to the axis of rotation of the rotor shaft; the radial direction also relates to this axis of rotation, and the circumferential direction is also related to this axis of rotation. In an advantageous embodiment, the interconnection unit is connected to the stator winding and / or the stator laminated core, in particular is firmly connected, in particular plug-connected and / or adhesively connected. It is advantageous that the interconnection unit can be designed with a plastic body in which a mating connector part can be accommodated, so that an electrical plug connection can be provided between the interconnection unit and the power electronics.

[0016] In an advantageous embodiment, the power electronics comprises a circuit board on which the connector part is mounted, in particular by soldering contacts of the connector part to conductor tracks of the circuit board. This allows for simple, cost-effective production.

[0017] In an advantageous embodiment, a first surface area of ​​the power electronics is pressed against a heat sink, which is inserted into a recess in the bearing plate. In particular, the first surface area is a surface section of a power module mounted on the circuit board, in particular which has power semiconductors. In particular, a step is introduced at the edge of the recess in the bearing plate, against which step the heat sink is pressed, in particular with the elastic spring force generated by a spring element. It is advantageous that the power semiconductor switches can be integrated into the power module and the power module can be mounted on the circuit board.

[0018] In an advantageous embodiment, a fan is connected to the rotor shaft in a rotationally fixed manner, in particular wherein the air flow conveyed by the fan flows through a channel which passes through the first bearing plate in the axial direction, in particular parallel to the direction of the axis of rotation of the rotor shaft of the electric motor, which channel opens into the free space and through the free space. The advantage here is that the fan can be designed passively and therefore no additional fan drive is necessary. In an advantageous embodiment, cooling fins formed on the heat sink protrude into a free space formed between the bearing plate and the stator housing part, in particular wherein the free space is flowed through by an air flow conveyed by a fan. The advantage here is that a compact design is possible.

[0019] In an advantageous embodiment, a second surface region of the power electronics is pressed against a thickened portion of the bearing plate, in particular against a region of the bearing plate which has a greater wall thickness than the adjacent regions of the bearing plate, in particular by means of a spring force generated by a spring element or the spring element, in particular wherein the second surface region is a surface section of a heat-generating component mounted on the circuit board, in particular which component has at least one power semiconductor or is designed as a power semiconductor. The advantage here is that the power electronics can be cooled at two points. At the second surface region, a heat flow can be introduced into the bearing plate, which is spread out there and then dissipated into the ambient air.In the first surface area, a heat flow is diverted to the cooling air flow and thus to the ambient air via a heat sink, which can be made of a material with higher thermal conductivity than the material of the bearing shield.

[0020] A higher temperature is intended for the first surface area than for the second surface area. This is because heat dissipation via a heat sink results in a lower thermal resistance from the first surface area to the ambient air compared to the thermal resistance from the second surface area via the bearing shield to the ambient air.

[0021] For example, the heat sink can be made of aluminum and the first bearing plate of steel or cast steel.

[0022] In an advantageous embodiment, the power electronics are electrically connected to the signal electronics via a plug connection, in particular wherein a spring element is arranged in the junction box, in particular between the power electronics and the signal electronics, such that the signal electronics are pressed toward the cover part and the power electronics toward the base part, in particular wherein a surface region of the signal electronics is pressed against a thickened wall region, in particular wherein the surface region is a surface section of a heat-generating component mounted on a circuit board of the signal electronics. This is advantageous because it enables efficient manufacturing.

[0023] In an advantageous embodiment, a flange part for accommodating an additional bearing of the rotor shaft is connected to the stator housing part on the side of the stator housing part facing away from the first bearing plate. This is advantageous because it enables efficient manufacturing.

[0024] In an advantageous embodiment, the interconnection unit is plugged onto an axial end region of the stator winding. This allows for simple, fast, and efficient production. The interconnection unit establishes the star or delta connection of the electric motor, particularly a three-phase motor.

[0025] In an advantageous embodiment, the interconnection unit creates a star or delta connection of the stator winding. This is advantageous because the interconnection can be arranged compactly, particularly in the immediate vicinity of the stator winding.

[0026] In an advantageous embodiment, the bearing receptacle for the first bearing is formed as an area projecting in the axial direction towards the stator housing part on the bearing shield, wherein an annular collar area is formed on the bearing shield, which collar area extends circumferentially around the bearing receptacle in the axial direction towards the stator housing part on the bearing shield, which collar area is spaced from the bearing receptacle and which radially surrounds the bearing receptacle, in particular thus completely radially surrounds the bearing receptacle in the circumferential direction, wherein a stator of an angle sensor is arranged radially between the collar area and the bearing receptacle and is connected to the bearing shield, wherein a rotor part of the angle sensor is connected to the rotor shaft in a rotationally fixed manner, in particular wherein the rotor part has a printed circuit board to which a sheet metal part is connected in a rotationally fixed manner, which sheet metal part is arranged in the axial direction between the interconnection unit and the printed circuit board,In particular, for shielding the angle sensor from magnetic fields of the stator winding. The advantage here is that an angle sensor can be integrated into the motor compartment. Although the stator winding generates very strong alternating magnetic fields in the interior of the electric motor, the angle sensor has a shielding element arranged axially between the rotor part and the stator winding. The angle sensor can thus still be operated safely and with minimal error, even though the rotor part and stator of the angle sensor interact electromagnetically, particularly inductively. In particular, the angular position is determined by determining the inductance, and / or the number of revolutions is determined by determining the magnetic field of a permanent magnet rotatably mounted on the rotor part of the angle sensor.

[0027] In an advantageous embodiment, the stator of the angle sensor is connected to the signal electronics via a plug connection, with the plug connection extending through a recess extending through the first bearing plate. This has the advantage that the sensor signals can be evaluated directly in the signal electronics.

[0028] In an advantageous embodiment, a magnetic body is arranged on the side of the first bearing plate facing away from the stator housing part and is connected to the bearing plate. This advantageously dissipates the heat of the magnetic body via the bearing plate.

[0029] In an advantageous embodiment, a circumferentially extending step is formed on the magnet body, which rests against a circumferentially extending centering collar of the bearing plate. This is advantageous because it allows for easy centering of the magnet body.In an advantageous embodiment, a coil is accommodated in an annular recess of the magnetic body, wherein a ferromagnetic armature disk is arranged axially between the first bearing plate and the coil, wherein the armature disk is connected to the magnetic body in a rotationally fixed manner and is arranged to be displaceable in the axial direction, wherein a brake pad carrier arranged axially between the armature disk and the bearing plate is connected to the rotor shaft in a rotationally fixed manner and is arranged to be movable in the axial direction relative to the rotor shaft, in particular wherein the brake pad carrier has an internal toothing with which the brake pad carrier is placed onto an external toothing of an annular driver, wherein the driver is connected to the rotor shaft in a rotationally fixed manner, wherein the bearing plate has a flat surface acting as a braking surface, in particular a finely machined flat surface, wherein further spring elements supported on the magnetic body press onto the armature disk.The advantage of this is that the brake engages automatically in the event of a power failure. Furthermore, the frictional heat generated during braking is transferred to the bearing plate at the braking surface.

[0030] 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. The invention will now be explained in more detail with reference to schematic illustrations:

[0031] Figure 1 shows a first drive according to the invention with a bearing plate 1 in longitudinal section.

[0032] Figure 2 shows a second drive according to the invention in longitudinal section, which in addition to the embodiment according to Figure 1 has an electromagnetically actuated brake.

[0033] Figure 3 shows an oblique view of the bearing plate 1.

[0034] In Figure 4, the bearing plate 1 is shown in section.

[0035] As shown in Figure 1 together with Figures 3 and 4, the drive is designed as an electric motor which has a rotatably mounted rotor shaft 4.

[0036] A first bearing 8 for rotatably supporting the rotor shaft 4 is housed in the bearing plate 1, which is connected to a stator housing part 2. On the side facing away from the bearing plate 1, the stator housing part 2 is connected to a flange part 6, in which a second bearing 7 is housed, which is also designed for rotatably supporting the rotor shaft 4.

[0037] The bearing plate 1 has a portion formed as the lower part of a terminal box of the electric motor, onto which a cover part 13 is placed and connected. Signal electronics 16 and power electronics 15 are arranged within the cover part 13.

[0038] The signal electronics 16 is connected to the cover part, in particular in a heat-conducting manner. For this purpose, at least one surface area of ​​the signal electronics 16, in particular a heat-generating component mounted on a circuit board of the signal electronics 16, is pressed against the cover part 13. An elastic spring element is preferably provided for this purpose.

[0039] A first surface area of ​​the power electronics 15 is pressed against a heat sink 14, which is inserted into a recess in the bearing plate. A step is formed at the edge of the recess, against which the heat sink 14 is positioned and pressed by the elastic spring force generated by the spring element.

[0040] Cooling fins 40 formed on the heat sink 14 project into an area formed between the bearing shield 1 and the stator housing part 2, through which an air flow conveyed by a fan 11 flows.

[0041] The fan 11 is connected to the rotor shaft 4 in a rotationally fixed manner and is surrounded by a fan cover 12 which is connected to the bearing plate 1.

[0042] A second surface area of ​​the power electronics 15 is pressed against a thickened portion 19 of the bearing plate 1, in particular against an area of ​​the bearing plate 1 which has an increased wall thickness compared to the areas of the bearing plate 1 adjacent to it, in particular by means of a spring force generated by a spring element.

[0043] The power electronics 15 is electrically connected to the signal electronics 16 via a plug connection 17.

[0044] In the stator housing part 2, a stator laminated core 3 is accommodated, in which a stator winding is accommodated.

[0045] The bearing support for the bearing 8 formed on the bearing plate 1 protrudes axially from the bearing plate 1, in particular towards the stator laminated core 3.

[0046] The lower part formed on the bearing shield 1 overlaps in the axial direction with the stator housing part 2.

[0047] In addition, the bearing shield has an annular collar region that protrudes axially from the bearing shield 1 and overlaps the stator housing part 2 in the axial direction, as well as radially surrounding the bearing 8. This annular collar region is spaced apart from the bearing 8. The area covered by the collar region in the axial direction encompasses the area covered by the collar region in the axial direction. At least one connector part of the power electronics 15 is also arranged in the terminal box. The connector part is preferably mounted on the circuit board of the power electronics, in particular plugged in and soldered.

[0048] An angle sensor 10 is arranged in the annular space between the collar area projecting in the axial direction on the bearing plate 1 and the bearing holder also projecting in the axial direction on the bearing plate 1.

[0049] A stator of the angle sensor 10 is connected in a rotationally fixed manner to the bearing plate 1. A rotor part of the angle sensor 10, which is arranged rotatably relative to the stator of the angle sensor 10, is connected in a rotationally fixed manner to the rotor shaft 4. The rotor part of the angle sensor 10 is preferably designed as a printed circuit board, the conductor tracks of which are designed as windings suitable for detection by the stator of the angle sensor 10. Alternatively or additionally, a permanent magnet can be arranged on the rotor part of the angle sensor 10 so that the number of revolutions of the rotor part can be determined. In order to make the number determinable even in the event of a power failure, a pulse wire sensor, in particular a Wiegand sensor, can preferably be arranged on the stator part, which is operatively connected to the permanent magnet, in particular wherein a voltage pulse is triggered with each revolution of the rotor part, which supplies a counter for its incrementation.

[0050] A connection unit 9 is arranged in the axial direction between the rotor part, in particular the circuit board, and the stator winding of the electric motor. This connection unit 9 is pushed as a cap onto the axial end region of the stator winding facing the bearing 8, in particular onto the winding head of the stator winding of the electric motor facing the bearing 8.

[0051] The interconnection unit comprises sheet metal parts that are electrically connected to the stator winding wire ends and create a delta or star connection of the stator winding. The sheet metal parts, in particular copper sheet parts, are embedded and / or provided in a plastic injection-molded part of the interconnection unit 9.

[0052] In addition, a mating connector part is integrated into the interconnection unit 9, so that the mating connector part is plugged into the connector part of the power electronics 15. The connector part of the power electronics 15 protrudes through a recess in a base area of ​​the lower part formed on the bearing plate 1 and is then plugged into the connector part.

[0053] Thus, when mounting the bearing plate 1 to the stator housing part 2, not only a mechanical connection but also an electrical plug connection is carried out and / or effected.

[0054] The circuit board functioning as the rotor part of the angle sensor 10 preferably has a magnetic shield on its side opposite the stator of the angle sensor 10, which is thus arranged between the interconnection unit 9 and the stator of the angle sensor 10. The rotor part and the stator of the angle sensor 10 are axially spaced from one another; however, the radial distance range covered by the stator of the angle sensor 10 relative to the rotational axis of the rotor shaft includes the radial distance range covered by the rotor of the angle sensor 10.

[0055] In the embodiment shown in Figure 2, in contrast to the embodiment shown in Figure 1, an electromagnetically actuated brake is attached to the side of the bearing plate 1 facing away from the stator housing part 2. The non-rotating parts of the brake are therefore held by the bearing plate 1.

[0056] On the side of the bearing plate facing away from the stator housing part 2, a magnetic body 21 is arranged and connected to the bearing plate 1. For this purpose, the magnetic body 21 has a step that runs circumferentially around the axis of rotation of the rotor shaft 4 and bears against a centering collar of the bearing plate 1 that also runs circumferentially to center the magnetic body 21.

[0057] An annular recess is formed in the magnet body 21, in which an electrically energizable coil 20 is accommodated.

[0058] A ferromagnetic armature disk is arranged axially between the coil 20 and the bearing plate 1, which is guided and / or movable in the axial direction, wherein the armature disk is connected in a rotationally fixed manner to the magnetic body 21. A brake pad carrier 22 is arranged axially between the armature disk and the bearing plate 1, which has an internal toothing that is mounted on an external toothing of an annular driver 23.

[0059] The driver 23 is connected in a rotationally fixed manner to the rotor shaft 4. Thus, the brake pad carrier is connected in a rotationally fixed manner to the rotor shaft 4 and is arranged to be axially displaceable relative to the driver 23 and / or the rotor shaft 4.

[0060] When the coil 20 is energized, the armature disk is attracted to the coil 20 against the spring force generated by spring elements supported on the magnet body 21.

[0061] When the coil 20 is not energized, the spring elements press the armature disk away from the magnet body towards the brake pad carrier, which thus presses onto a particularly finely machined flat braking surface formed on the bearing plate 1.

[0062] Axially aligned bolts not shown in the figures are connected to the magnetic body 21 and protrude through recesses in the armature disk, in particular for guiding the armature disk during its axial movement.

[0063] Preferably, the brake pad carrier 22 has an axially projecting collar region, in the radial inner side of which the internal toothing of the brake pad carrier 22 extends and which is arranged radially between the bearing plate 1 and the driver 23.

[0064] The bearing plate 1 therefore not only functions as a bearing support for the bearing 8 and as a passage for the electrical interface from the power electronics 15 to the interconnection unit 9, but also to accommodate the power electronics 15 in the terminal box and to dissipate the heat loss of the power electronics 15. In addition, the frictional heat of the electromagnetically actuated brake is also dissipated to the bearing plate 1.

[0065] Due to the shape of the bearing plate 1 and its large mass, particularly its heat capacity, the heat supplied to the bearing plate is spread, particularly between the brake, the stator, and the electronics. Thus, when braking is initiated, the power electronics are shut down or at least subjected to only a minimal load, with little flow through the stator and its load also being minimal. Thus, while an increased heat flow into the bearing plate from the brake area is generated, important heat flows from the stator and electronics are eliminated.

[0066] Conversely, when the brake is open, the generation of a high torque causes a large heat flow from the electronics and the stator into the bearing plate 1, although no significant heat flow is introduced into the bearing plate 1 by the brake. Rather, the magnetic body 21 is designed and connected to the bearing plate 1 in such a way that heat from the bearing plate 1 flows into the then cooler magnetic body 21 and from there into the environment.

[0067] In addition, the air flow conveyed by the fan 11 not only flows around the magnetic body 21, but also flows through the continuous channel present in the bearing shield and the area between the stator housing part 2 and the bearing shield 1.

[0068] In further embodiments according to the invention, the coil 20 is supplied from the power electronics 15. For this purpose, a plug connection is also provided between the power electronics 15, in particular between the circuit board of the power electronics 15, and the magnetic body 21, wherein a further plug connector part is held by the circuit board and a further mating plug connector part corresponding to the further plug connector part is held on the magnetic body 21.

[0069] List of reference symbols

[0070] 1 bearing plate

[0071] 2 Stator housing part

[0072] 3 stator lamination pack

[0073] 4 Rotor shaft

[0074] 5 Squirrel cage

[0075] 6 Flange part

[0076] 7 camps

[0077] 8 warehouses

[0078] 9 Interconnection unit

[0079] 10 Angle sensor

[0080] 11 fans

[0081] 12 Fan cover

[0082] 13 Lid part

[0083] 14 heat sinks

[0084] 15 Power electronics

[0085] 16 Signal electronics

[0086] 17 Plug connection

[0087] 18 Connector part

[0088] 19 Thickening

[0089] 20 coil

[0090] 21 magnetic bodies

[0091] 22 brake pad carrier

[0092] 23 Driver, ring-shaped with external teeth

[0093] 40 cooling fins

Claims

Patent claims:

1. Drive, in particular an electric motor, with a terminal box, wherein a stator housing part of the drive is connected to a first bearing plate on which a bearing receptacle for a first bearing for rotatable support of the rotor shaft is formed, characterized in that a lower part, in particular a trough-shaped lower part, is formed on the bearing plate, onto which a cover part of the drive is placed, in particular and connected to the lower part, wherein a stator lamination stack is received in the stator housing part in which a stator winding formed from winding wire is arranged, wherein the ends of the winding wire are led to a connection unit with which a mating connector part is connected, which is plug-connected to a connector part which is comprised of power electronics which are arranged inside the terminal box.

2. Drive according to claim 1, characterized in that the interconnection unit is connected to the stator winding and / or the stator lamination stack, in particular is firmly connected, in particular is plug-connected and / or adhesively connected.

3. Drive according to one of the preceding claims, characterized in that the power electronics comprise a printed circuit board on which the connector part is mounted, in particular by soldering contacts of the connector part to conductor tracks of the printed circuit board and / or that the heat sink is made of a material with higher thermal conductivity than the material of the first bearing shield, in particular wherein the heat sink is made of aluminum and the bearing shield is made of steel or cast steel.

4. Drive according to one of the preceding claims, characterized in that a first surface area of ​​the power electronics is pressed against a heat sink which is inserted into a recess of the bearing shield, in particular wherein the first surface area is a surface section of a power module mounted on the circuit board, in particular which has power semiconductors, in particular wherein a step is provided at the edge of the recess in the bearing shield against which the heat sink is pressed, in particular with the elastic spring force generated by a spring element.

5. Drive according to one of the preceding claims, characterized in that a fan is rotatably connected to the rotor shaft, in particular wherein the airflow conveyed by the fan passes through a channel through the first bearing shield in an axial direction, in particular parallel to the direction of the axis of rotation of the rotor shaft of the electric motor, which opens into the free space, and through the free space.

6. Drive according to one of the preceding claims, characterized in that cooling fins formed on the cooling element project into a free space formed between the bearing shield and the stator housing part, in particular wherein the free space is traversed by an airflow conveyed by a fan.

7. Drive according to one of the preceding claims, characterized in that a second surface area of ​​the power electronics is pressed against a thickening of the bearing shield, in particular against an area of ​​the bearing shield which has an increased wall thickness compared to the areas of the bearing shield adjacent to it, in particular by means of a spring force generated by a spring element, in particular wherein the second surface area is a surface section of a heat-generating component mounted on the circuit board, in particular which has at least one power semiconductor or is designed as a power semiconductor.

8. Drive according to one of the preceding claims, characterized in that the power electronics are electrically connected to the signal electronics via a plug connection, in particular wherein a spring element is arranged in the connection box, in particular between the power electronics and the signal electronics, such that the signal electronics are pressed towards the cover part and the power electronics towards the lower part, in particular wherein a surface area of ​​the signal electronics is pressed against a thickened wall area, in particular wherein the surface area is a surface section of a heat-generating component mounted on a circuit board of the signal electronics.

9. Drive according to one of the preceding claims, characterized in that a flange part for receiving a further bearing of the rotor shaft is connected to the stator housing part on the side of the stator housing part facing away from the first bearing shield.

10. Drive according to one of the preceding claims, characterized in that the interconnection unit is mounted on an axial end region of the stator winding.

11. Drive according to one of the preceding claims, characterized in that the interconnection unit effects a star connection or delta connection of the stator winding.

12. Drive according to one of the preceding claims, characterized in that the bearing receptacle for the first bearing is formed as a region projecting axially towards the stator housing part on the bearing shield, wherein an annular collar region projecting axially towards the stator housing part is formed on the bearing shield, which is spaced apart from the bearing receptacle and which radially surrounds the bearing receptacle, in particular completely radially surrounding it in the circumferential direction, wherein a stator of an angle sensor is arranged radially between the collar region and the bearing receptacle and is connected to the bearing shield, wherein a rotor part of the angle sensor is rotationally fixed to the rotor shaft, in particular wherein the rotor part has a circuit board to which a sheet metal part is rotationally fixed, which is arranged axially between the interconnection unit and the circuit board.especially for shielding the angle sensor from magnetic fields of the stator winding.

13. Drive according to one of the preceding claims, characterized in that the stator of the angle sensor is connected to the signal electronics by means of a plug connection, wherein the plug connection protrudes through a recess through the first bearing shield.

14. Drive according to one of the preceding claims, characterized in that a magnetic body is arranged on the side of the first bearing shield facing away from the stator housing part, which is connected to the bearing shield, in particular wherein a circumferentially circumferential step is formed on the magnetic body, which bears against a circumferentially circumferential centering collar of the bearing shield.

15. Drive according to one of the preceding claims, characterized in that a coil is received in an annular recess of the magnet body, wherein a ferromagnetic armature disk is arranged axially between the first bearing plate and the coil, wherein the armature disk is rotationally fixed to the magnet body and is arranged to be displaceable in the axial direction, wherein a brake pad carrier arranged axially between the armature disk and the bearing plate is rotationally fixed to the rotor shaft and is arranged to be movable in the axial direction relative to the rotor shaft, in particular wherein the brake pad carrier has an internal toothing with which the brake pad carrier is mounted onto an external toothing of an annular driver, wherein the driver is rotationally fixed to the rotor shaft, wherein the bearing plate has a flat surface, in particular a finely machined surface, which serves as a braking surface.where additional spring elements supported on the magnet body press against the armature disc.

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