Electric motor having a rotor shaft, in particular a rotatably mounted rotor shaft, and an angle sensor

Abstract

A brake arrangement for braking a shaft (15), wherein the brake arrangement has - a receiving part (10), - a lining carrier (12), - an armature disc (11), - a part (17) having a brake surface, wherein the lining carrier (12) is arranged for conjoint rotation with the shaft (15) and is movable in an axial direction, wherein the armature disc (11) is connected to the receiving part (10) for conjoint rotation, wherein the armature disc (11) is arranged axially between the lining carrier (12) and the receiving part (10), wherein the lining carrier (12) is arranged axially between the armature disc (11) and the part (17) having a brake surface, wherein the brake arrangement has a linear actuator element, wherein the linear actuator element has a shape-memory material, and wherein the linear actuator element is connected to the armature disc (11) and to the receiving part (10).

Description

[0001] Electric motor, comprising a rotor shaft, in particular a rotatably mounted rotor shaft, and an angle sensor

[0002] Description:

[0003] The invention relates to an electric motor comprising a rotor shaft, in particular a rotatably mounted rotor shaft, and an angle sensor.

[0004] It is generally known that the angular position of a rotor shaft can be detected using angle sensors.

[0005] From EP 0 326 966 A2, an electromagnetically actuated spring-loaded brake is known as the closest prior art.

[0006] From DE 10 2005 055 759 A1 a device for producing a frictional and / or positive connection between two components arranged so as to be rotatable or linearly movable relative to one another is known.

[0007] A friction clutch is known from DE 40 09626 A1.

[0008] An automatic brake is known from US 2 966 240 A.

[0009] A switchable clutch with air temperature dependent function is known from DE 20 2010 014 483 U1.

[0010] The invention is therefore based on the object of further developing an angle detection system for a rotor shaft, whereby a robust mode of operation is to be achieved.

[0011] According to the invention, the object is achieved in the electric motor according to the features specified in claim 1.

[0012] Important features of the invention in the brake assembly for braking a shaft, in particular a rotor shaft of an electric motor, are that the brake assembly comprises a receiving part, a lining carrier, in particular a brake lining carrier, in particular a disc-shaped brake lining carrier having a brake lining on each axial side, an armature disk, a part having a braking surface, in particular a bearing plate, wherein the lining carrier is arranged in a rotationally fixed manner with the shaft and displaceable in the axial direction, in particular parallel to the axis of rotation of the shaft, wherein the armature disk is connected in a rotationally fixed manner to the receiving part, in particular by bolts attached to the receiving part projecting through the armature disk in the axial direction, wherein the armature disk is arranged axially between the lining carrier and the receiving part, wherein the lining carrier is arranged axially between the armature disk and the part having the braking surface,wherein the brake assembly comprises a linear actuator element, wherein the linear actuator element comprises a shape memory material, in particular a shape memory material part, wherein the linear actuator element is connected on the one hand to the armature disk and on the other hand to the receiving part, in particular such that the armature disk is pressed by the linear actuator element at a first temperature of the shape memory material to a first axial position relative to the receiving part and at a second temperature of the shape memory material to a second axial position relative to the receiving part, in particular wherein the first temperature is lower than the second temperature and the armature disk has a greater distance from the receiving part in the first axial position than in the second axial position.

[0013] The advantage here is that the permanent release can be carried out in an energy-saving manner, as no spring force needs to be overcome; instead, a sufficiently high temperature must be provided in the shape memory material. In the event of a power failure or when the power supply is switched off, the shape memory material cools down automatically and thus automatically moves the armature disk to the first position, in which the armature disk has a greater distance from the receiving element, measured in the axial direction, than in the second position. The armature disk, moved into the first position, presses the lining carrier onto the braking surface located on the side of the lining carrier facing away from the armature disk. The brake is therefore preferably used as a holding brake.

[0014] The use of the brake assembly as a holding brake on a converter-fed synchronous motor is particularly preferred. This is because the converter-fed and speed-controlled synchronous motor can be brought to a standstill while applying torque against the torque generated by the load driven by the synchronous motor. Therefore, the brake assembly can only be activated when the synchronous motor is at a standstill, making it particularly suitable for use as a holding brake.

[0015] Preferably, the shape memory material is shaped as a helical spring and

[0016] Preferably, an alloy of nickel and titanium, in particular with an admixture of copper, is used as the shape memory material.

[0017] In an advantageous embodiment, the shape memory material has electrical contacts at at least two points for supplying electrical current, in particular is in contact with a respective electrical line. This is advantageous in that electrical current can flow through the shape memory material itself and is heated in the process, in particular by means of ohmic heat loss. In an advantageous embodiment, the shape memory material is guided in a bore in the receiving part. This is advantageous in that the shape memory material expands or shrinks depending on the temperature and is guided in the bore, which is axially directed and thus ensures that the change in length remains and / or occurs in the axial direction.

[0018] In an advantageous embodiment, an electric heating element is arranged on the shape memory material, and the electric heating element is in thermally conductive contact with the shape memory material, in particular, wherein the heat transfer resistance from the heating element to the shape memory material is lower than the heat transfer resistance from the shape memory material to the surrounding area of ​​the shape memory material not covered by the heating element. The advantage here is that the electric heating element can be realized cost-effectively using an electrically energized heating wire, and the low heat transfer resistance, i.e., the thermally conductive contact, enables rapid heating of the shape memory material.

[0019] In an advantageous embodiment, a Peltier element is arranged in contact with the shape memory material. This is advantageous because the Peltier element is thermally conductively connected to the shape memory material, which allows for rapid cooling of the cold side of the Peltier element and thus rapid application of the brake. Of course, simultaneous energization of the electrical heating element and the Peltier element is avoided. It is also important that only a brief energization of the Peltier element is necessary for the aforementioned cooling.

[0020] In an advantageous embodiment, a thermally insulating material surrounds the shape memory material, particularly in contact with it. This is advantageous in that a lower current is sufficient for heating, as the energy loss is reduced.

[0021] In an advantageous embodiment, the Peltier element is arranged in a recess extending through the thermally insulating material. This advantageously involves the cold side of the Peltier element being in contact with the shape memory material, while the hot side of the Peltier element is thermally conductively connected to the environment, thus allowing heat to be dissipated to the environment.

[0022] In an advantageous embodiment, a temperature sensor is arranged on the shape memory material to detect the temperature of the shape memory material. The temperature sensor is connected to signal electronics that energizes the electric heating element and the Peltier element in such a way that the temperature detected by the temperature sensor is regulated to a respective target value. This is advantageous in that the shape memory material can be temperature-controlled in a predetermined manner, thus enabling rapid application or release of the brake. Furthermore, the brake assembly can even be operated in a warm environment, although in this case, the Peltier element must be continuously energized.

[0023] In an advantageous embodiment, the receiving part is a housing-forming part of the brake assembly. Advantageously, the brake assembly is surrounded by the receiving part and the part containing the braking surface, forming a housing.

[0024] In an advantageous embodiment, the receiving part radially surrounds the linear actuator element. This is advantageous because the linear actuator element is arranged in a protected manner.

[0025] In particular, the axial direction is always aligned parallel to the axis of rotation of the shaft and the circumferential direction is related to the axis of rotation of the shaft and the radial direction and / or the respective radial distances are related to the axis of rotation of the shaft.

[0026] In an advantageous embodiment, the linear actuator element is screwed into a threaded hole in the receiving part. This provides the advantage of using an easily operable connection. Alternatively, a material-to-material connection could be implemented, but this cannot be removed without causing damage.

[0027] In an advantageous embodiment, the linear actuator element is screwed into a threaded hole in the armature disk. This provides the advantage of using an easily operable connection. Alternatively, a material-to-material connection could be implemented, but this cannot be removed without damage. In an advantageous embodiment, the shape memory material is helical and / or designed as a helical spring. This is advantageous in that, in an electromagnetically actuated brake according to the prior art, a spring part can be exchanged for the inventive linear actuator with shape memory material, thus allowing an existing brake to be easily retrofitted according to the invention.

[0028] In an advantageous embodiment, the receiving part is connected in a rotationally fixed manner to a braking surface part having a braking surface. Advantageously, the brake assembly can be surrounded by the two parts to form a housing.

[0029] In an advantageous embodiment, in the first position, the brake pad carrier is pressed by the armature disc onto the braking surface formed on the braking surface part. This is advantageous because, in the event of a power failure and cooling, the shape-memory material presses the armature disc toward the brake pad carrier, thus pressing the armature disc onto the brake pad of the brake pad carrier facing it, so that the brake pad carrier, with its brake pad arranged on the side of the brake pad carrier axially facing away from the armature disc, is pressed onto the braking surface. It is important here that, in the event of a power failure, the brake engages automatically, in particular through human actuation caused by the laws of nature. This ensures a high level of safety.

[0030] In an advantageous embodiment, the armature disc is pulled toward the receiving part in the second position, particularly so that the lining carrier moves freely away from the braking surface. This is advantageous because the armature disc is pulled away from the lining carrier with minimal heating power, allowing the lining carrier to move freely away from the braking surface.

[0031] In an advantageous embodiment, an annular driver is pushed onto the shaft, which driver has an external toothing and is connected to the shaft in a rotationally fixed manner, in particular by means of a keyway connection, wherein the lining carrier has an internal toothing and is pushed onto the external toothing, wherein the internal toothing is in engagement with the external toothing, in particular wherein bolts fastened to the receiving part, in particular axially directed bolts, protrude through recesses of the armature plate in the axial direction, in particular so that the armature plate is connected to the receiving part in a rotationally fixed manner and is axially movable, in particular wherein the braking surface part is connected to the receiving part in a rotationally fixed manner, and / or that the driver is pushed onto the shaft and connected in a form-fitting manner, the lining carrier can be pushed onto the driver and the armature plate is made of a diamagnetic, in particular non-ferromagnetic, material,such as aluminum or plastic.

[0032] In an advantageous embodiment, an angle sensor of the brake arrangement has a sensor shaft and a housing, wherein the sensor shaft is connected to the rotor shaft in a rotationally fixed manner by means of a coupling, wherein the coupling has a first coupling part, a second coupling part and a damping part arranged between the first and second coupling parts, wherein the first coupling part is connected to the rotor shaft in a rotationally fixed manner and the sensor shaft is connected to the second coupling part in a rotationally fixed manner. The advantage here is that the angle sensor is not subject to magnetic or electromagnetic interference from the brake. This is because the brake can be operated without static or alternating magnetic fields, which would be necessary with an electromagnetically actuated brake. Furthermore, the torque change upon application of the brake is decoupled from the angle sensor, since the angle sensor is only connected via the damping part. Overall, robust operation is thus achieved in a cost-effective manner.This leads to a longer service life of the wearing parts and thus to an overall energy saving, since replacement of the brake assembly is required less frequently and thus less energy is required to manufacture it.

[0033] Important features of the brake motor comprising an electric motor and a brake assembly are that the electric motor is a synchronous motor and the brake assembly functions as a holding brake, in particular not as a working brake. The advantage here is that the slower engagement of the brake assembly according to the invention compared to electromagnetically actuated brakes is irrelevant, since the rotor shaft is first actuated by the synchronous motor, which, by its very nature, can generate a correspondingly high torque even at the lowest speeds.

[0034] Important features in the method for operating a brake motor, comprising an electric motor and a brake arrangement, are that the electric motor is a three-phase motor fed by a converter, in particular wherein the speed of the three-phase motor is controlled and / or regulated by the converter, wherein the three-phase motor is a synchronous motor, and wherein in a first method step the speed of the three-phase motor is regulated to zero, wherein the brake arrangement is released, and wherein in a second method step following the first method step the brake arrangement is activated, i.e. applied, in order to hold the rotor shaft of the three-phase motor at a standstill, in particular wherein the electric motor is a synchronous motor and the brake arrangement functions as a holding brake, in particular therefore not as a working brake.

[0035] The advantage here is that the synchronous motor is used to brake first and only then is the brake acting as a holding brake activated.

[0036] 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:

[0037] Figure 1 shows a cross section through a section of an electric motor not according to the invention with a brake and angle sensor 6, wherein a coupling is arranged between the rotor shaft 15 and the angle sensor.

[0038] As shown in Figure 1, the electric motor has a bearing flange 17 which is connected to the stator of the electric motor and accommodates a bearing 16 by means of which the rotor shaft 15 is rotatably mounted.

[0039] A braking surface is formed on the bearing flange 17 on the side facing the brake.

[0040] A driver 13 is mounted on the rotor shaft 15 and is connected to the rotor shaft 15 in a rotationally fixed manner, in particular by means of a positive-locking rotationally fixed connection to the rotor shaft 15. The driver 13 is ring-shaped and is connected to the rotor shaft in a rotationally fixed manner by means of a key connection, in particular using a key 14 arranged between the rotor shaft 15 and the driver 13.

[0041] The driver 13 has external teeth. In particular, these external teeth extend in the axial direction, i.e., parallel to the rotational axis of the rotor shaft.

[0042] A brake pad carrier 12 is slid onto the driver 13. This hollow design has internal teeth on its inside that mesh with the external teeth. Thus, the brake pad carrier 12 is connected to the rotor shaft 15 in a rotationally fixed but axially movable manner.

[0043] A magnetic body 10 is connected to the bearing flange in a rotationally fixed manner, in particular by screwing. The magnetic body has an annular circumferential recess in which an electrically energizable winding 8 is accommodated.

[0044] The winding 8 is designed as a toroidal winding, with the ring axis being the rotational axis of the rotor shaft 15. An armature disk 11 is connected to the magnetic body 10 in a rotationally fixed but axially displaceable manner. A spring member 9 supported on the magnetic body 10 presses on the armature disk 11, so that when the winding is energized, the armature disk 11 overcomes the spring force generated by the spring member 9 and is drawn toward the magnetic body 10, in particular toward the winding 8, thereby releasing the brake.

[0045] When the winding 8 is de-energized, the spring member 9 presses the armature disk 11 toward the brake pad carrier 12, so that the latter is pressed onto the braking surface formed on the bearing flange 17. Thus, the brake pad carrier 12, which is provided with brake pads on both sides axially, is brought into frictional contact between the armature disk 11 and the braking surface, so that the brake is applied when the current is de-energized.

[0046] When the brake is released and also when it is applied, a torque jerk is introduced into the rotor shaft 15. However, a load, such as torque jerk and / or transverse torque, can also be introduced on the load side.

[0047] In order to allow an angle sensor 6 to detect the angular position of the rotor shaft 15 with as little interference as possible, a coupling is arranged according to the invention between the rotor shaft 15 and the sensor 6.

[0048] The coupling has a first coupling part 1 which is connected in a rotationally fixed manner to the rotor shaft 15, and a second coupling part 2 which is connected in a rotationally fixed manner to the rotor of the sensor.

[0049] A damping part 3 is arranged between the first and second coupling parts (1, 2). The damping part 3 is preferably made of an elastomer, in particular rubber or plastic.

[0050] The first coupling part 1 has an external thread at its axial end region facing the rotor shaft 15, with which the rotor shaft 15 is screwed into an axially directed threaded bore centrally formed in the rotor shaft 16. During production, the damping part 3 is pressed onto the second coupling part 2, and then the first coupling part 1 is slipped over the damping part 3 and pressed on.

[0051] In this way, a backlash-free torque transmission is possible.

[0052] The housing of the sensor 6 is connected to a fan cover, particularly for torque support. The fan cover 7 is directly or indirectly connected to the magnet body 10 and / or the bearing flange 17.

[0053] In the electric motor with the brake arrangement according to the invention, one spring part 9 or several of the spring parts 9 spaced apart from one another in the circumferential direction are replaced by a linear actuator element which is connected on the one hand to the magnetic body 10 and on the other hand to the armature disk 11.

[0054] The linear actuator element comprises a shape memory material such that at a first temperature the linear actuator element reaches a first length measured in the axial direction and at a second temperature which is higher than the first temperature the linear actuator element contracts to a second length measured in the axial direction.

[0055] An electrical heating element is applied to the shape memory material, or the shape memory material can be heated by applying current. This allows the temperature of the linear actuator element to be electrically controlled.

[0056] At the first temperature, i.e. at the cooler of the two temperatures, the armature disk 11 is thus pressed by the linear actuator element onto the brake pad carrier 12, which is thereby pressed onto a braking surface formed on the bearing flange 17, in particular finely machined, in particular ground, in particular on the side of the brake pad carrier facing away from the armature disk 11.

[0057] At the second temperature, the linear actuator element pulls the armature disk 11 toward the magnetic body 10. Thus, when the linear actuator element cools down, the brake is released. Cooling can be achieved, for example, in the event of a power failure. Like the spring part 9, which is replaced by the linear actuator element, the linear actuator element is housed in an axial bore of the magnetic body 10. Unlike the spring part 9, however, the linear actuator element is attached to the magnetic body 10 at its end region facing away from the armature disk 11. At its other end region, the linear actuator element is attached to the armature disk 11.

[0058] In this case, a material-to-material connection is preferably provided between the linear actuator element and the armature disk 11. The connection to the magnetic body 10 can also be provided as a material-to-material connection, with a screw connection being preferred if the axial bore is designed as a threaded bore. For example, a threaded pin can be screwed into the threaded axial bore, to which the shape-memory material, designed as a spiral spring, can be connected. In particular, the threaded pin has a hook for this purpose, so that the linear actuator element can be hooked in with its counter-hook.

[0059] In this way, the linear actuator element is connected axially on both sides and positions the armature disk 11 depending on the temperature.

[0060] The linear actuator elements are spaced apart from each other in the circumferential direction.

[0061] Preferably, heating is achieved by applying current to the shape memory material itself rather than through a separate heating element. Thus, only a short-circuit-proof design of the linear actuator element is required.

[0062] Further preferably, the shape memory material is formed as a spiral, in particular in the form of a spiral spring. The spiral is connected at its first end to the magnetic body 10, and the other end of the spiral is connected to the armature disk 11.

[0063] If all spring parts 9 are replaced by linear actuator elements, the winding 8 is also not necessary, and the magnetic body 10 no longer has to be made of ferromagnetic material, but can also be made of a non-ferromagnetic material, such as aluminum or plastic. In further embodiments according to the invention, not all spring parts 9 are replaced by linear actuator elements, and the winding 8 is still present. Thus, the brake can still be actuated electromagnetically, i.e., when energized, the winding 8 can be released against the spring force generated by the remaining spring parts 9. In addition, the linear actuator elements support the release process by heating the linear actuator elements, particularly synchronously with the energization of the winding 8.

[0064] In further embodiments according to the invention, the linear actuator element(s) is / are each surrounded by a thermally insulating material. Thus, the minimum current required for continuous ventilation is small. Optionally, a Peltier element is additionally arranged on the shape memory material so that the Peltier element is in thermally conductive contact with the shape memory material and, when energized, the shape memory material is cooled by the Peltier element. The Peltier element is arranged in a recess in the thermally insulating material that extends through the thermally insulating material. Thus, the Peltier element conducts a heat flow through the thermally insulating material, in particular that which covers the remaining surface of the shape memory material not covered by the Peltier element or the heating element.

[0065] In further embodiments of the invention, a temperature sensor is arranged on the shape memory material, which detects the actual temperature of the shape memory material. The temperature sensor is electrically connected to signal electronics, from which the heating element and the Peltier element can be electrically powered. The actual temperature of the shape memory material detected by the temperature sensor is adjusted to the desired setpoint by supplying current to either the heating element or the Peltier element. In this way, either a first or a second temperature of the shape memory material can be specified as a setpoint and reached by adjusting it, thus activating or releasing the brake.

[0066] 1 first coupling part

[0067] 2 second coupling part

[0068] 3 Damping part

[0069] 4 external threads

[0070] 5 screw

[0071] 6 Angle sensor

[0072] 7 Fan cover

[0073] 8 windings

[0074] 9 Spring part

[0075] 10 magnetic bodies

[0076] 11 Anchor disc

[0077] 12 brake pad carriers

[0078] 13 Drivers with external teeth

[0079] 14 key

[0080] 15 Rotor shaft

[0081] 16 warehouses

[0082] 17 Bearing flange

[0083] 18 Sensor shaft

Claims

Patent claims:

1. Brake arrangement for braking a shaft, in particular a rotor shaft of an electric motor, wherein the brake arrangement comprises a receiving part, a lining carrier, in particular a brake lining carrier, an armature disk, a part having a braking surface, in particular a bearing plate, wherein the lining carrier is connected to the shaft in a rotationally fixed manner and is arranged displaceably in the axial direction, in particular parallel to the axis of rotation of the shaft, wherein the armature disk is connected to the receiving part in a rotationally fixed manner, in particular by bolts fastened to the receiving part protruding through the armature disk in the axial direction, wherein the armature disk is arranged axially between the lining carrier and the receiving part, wherein the lining carrier is arranged axially between the armature disk and the part having the braking surface, characterized in that the brake arrangement comprises a linear actuator element, wherein the linear actuator element comprises a shape memory material,in particular a shape memory material part, wherein the linear actuator element is connected on the one hand to the armature disk and on the other hand to the receiving part, in particular so that the armature disk of the linear actuator element - at a first temperature of the shape memory material to a relative to the Receiving part is pressed into a first axial position and, at a second temperature of the shape memory material, is pressed into a second axial position relative to the receiving part, in particular wherein the first temperature is lower than the second temperature and the armature disk is at a greater distance from the receiving part in the first axial position than in the second axial position, in particular wherein the axial direction is aligned parallel to the direction of the axis of rotation of the shaft.

2. Brake arrangement according to claim 1, characterized in that the shape memory material for supplying electric current has an electrical contact at at least two points, in particular is in contact with a respective electrical line.

3. Brake arrangement according to one of the preceding claims, characterized in that an electrical heating element is arranged on the shape memory material and the electrical heating element is in thermally conductive connection with the shape memory material, in particular wherein the heat transfer resistance from the heating element to the shape memory material is smaller than the heat transfer resistance from the shape memory material to the other surroundings of the shape memory material not covered by the heating element.

4. Brake arrangement according to one of the preceding claims, characterized in that a Peltier element is arranged in contact with the shape memory material, and / or that the Peltier element is arranged in a recess passing through the thermally insulating material.

5. Brake arrangement according to one of the preceding claims, characterized in that a temperature sensor for detecting the temperature of the shape memory material is arranged on the shape memory material, wherein the temperature sensor is connected to signal electronics which are designed to energize the electrical heating element and / or the Peltier element in such a way that the temperature detected by the temperature sensor is regulated to a currently predetermined setpoint value, in particular wherein the setpoint value is either equal to the first temperature or equal to the second temperature.

6. Brake arrangement according to one of the preceding claims, characterized in that a thermally insulating material surrounds the shape memory material, in particular surrounds it in contact.

7. Brake arrangement according to one of the preceding claims, characterized in that the shape memory material is guided in a bore of the receiving part.

8. Brake arrangement according to one of the preceding claims, characterized in that the receiving part is a housing-forming part of the brake arrangement and / or that the receiving part radially surrounds the linear actuator element.

9. Brake arrangement according to one of the preceding claims, characterized in that the axial direction is aligned parallel to the axis of rotation of the shaft, and / or that the circumferential direction is related to the axis of rotation of the shaft and / or that the radial direction and / or the respective radial distances are related to the axis of rotation of the shaft.

10. Brake arrangement according to one of the preceding claims, characterized in that the linear actuator element is screwed on the one hand into a threaded bore of the receiving part and / or that the linear actuator element is screwed on the other hand into a threaded bore of the armature disk.

11. Brake arrangement according to one of the preceding claims, characterized in that the shape memory material is helical and / or designed as a helical spring.

12. Brake arrangement according to one of the preceding claims, characterized in that the receiving part is connected in a rotationally fixed manner to a braking surface part having a braking surface.

13. Brake arrangement according to one of the preceding claims, characterized in that in the first position the lining carrier is pressed by the armature disc onto the braking surface formed on the braking surface part and in the second position the armature disc is pulled towards the receiving part, in particular so that the lining carrier runs free from the braking surface.

14. Brake arrangement according to one of the preceding claims, characterized in that an annular driver is pushed onto the shaft, which has an external toothing and which is connected to the shaft in a rotationally fixed manner, in particular by means of a key connection, wherein the lining carrier has an internal toothing and is pushed onto the external toothing, wherein the internal toothing is in engagement with the external toothing, in particular wherein bolts fastened to the receiving part, in particular axially directed bolts, protrude through recesses in the armature disk in the axial direction, in particular so that the armature disk is connected to the receiving part in a rotationally fixed manner and is axially movable, in particular wherein the braking surface part is connected to the receiving part in a rotationally fixed manner, and / or that an angle sensor of the brake arrangement has a sensor shaft and a housing, wherein the sensor shaft is connected to the rotor shaft in a rotationally fixed manner by means of a coupling,wherein the coupling comprises a first coupling part, a second coupling part and a damping part arranged between the first and second coupling parts, wherein the first coupling part is connected in a rotationally fixed manner to the rotor shaft and the sensor shaft is connected in a rotationally fixed manner to the second coupling part.

15. Brake motor, comprising an electric motor and a brake arrangement according to one of the preceding claims, in particular wherein the electric motor is a synchronous motor and the brake arrangement functions as a holding brake, in particular not as a working brake.

16. A method for operating a brake motor, comprising an electric motor and a brake arrangement according to one of the preceding claims, wherein the electric motor is a three-phase motor fed by a converter, in particular wherein the speed of the three-phase motor is controlled and / or regulated by the converter, characterized in that the three-phase motor is a synchronous motor, and in that in a first method step the speed of the three-phase motor is regulated to zero, wherein the brake arrangement is released, and in that in a second method step following the first method step the brake arrangement is activated, i.e. applied, in order to hold the rotor shaft of the three-phase motor at a standstill, in particular wherein the electric motor is a synchronous motor and the brake arrangement functions as a holding brake, in particular therefore not as a working brake.

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