Sensor arrangement for a drive train of a bicycle

Abstract

The present invention relates to a sensor arrangement for a drive train of a bicycle. The drive train comprises an electric motor having a rotor (10) and a housing (12) having an interior space. The sensor arrangement comprises a sensor (14), a transmission unit (16), a reception unit (22) and a feedthrough unit (24). The sensor (14) and the transmission unit (16) have a torque-proof connection to the rotor (10) of the electric motor. The transmission unit (16) is designed to transmit a sensor signal to the reception unit (22). The reception unit (22) is secured to the housing (12) in the interior space. The feedthrough unit (24) is designed to provide an electrical interface (24) to the reception unit (22) through the housing (12). The invention also relates to a drive train for a bicycle.

Description

[0001] Sensor arrangement for a drive train of a bicycle

[0002] Technical area

[0003] The present invention relates to a sensor arrangement for a drive train of a bicycle. The invention also relates to a drive train.

[0004] State of the art

[0005] Bicycles can be equipped with a drive motor to assist the rider in propelling the bicycle using muscle power. For example, a bicycle can have an electric motor. For example, a bicycle can be designed as a pedelec.

[0006] However, integrating such a drive motor into a bicycle frame is difficult. The space available for the drive motor is limited. Furthermore, a gearbox is usually required, providing different gear ratios and, for example, summing the drive force from the drive motor and the rider. Access openings are often small and, alternatively or additionally, are only provided on one side to avoid excessively weakening the bicycle frame.

[0007] In addition, it is desirable to measure relevant operating variables in the drive train to enable user-friendly control of the drive motor. However, the integration and installation of the required sensor array is particularly difficult due to the limited space available. Furthermore, measurements often require the use of moving parts, which presents additional challenges for sensor signal transmission.

[0008] Description of the invention A first aspect relates to a sensor arrangement for a drive train of a bicycle. The bicycle can, for example, have two wheels. The bicycle can be designed as a pedelec. The drive train has an electric motor with a rotor and a housing with an interior. The rotor can be operatively connected to an output of the drive train. The electric motor can thus assist a user in driving the bicycle. The electric motor can, for example, be designed as a synchronous machine or an asynchronous machine. The drive train can have a power supply for the electric motor, such as a battery. The electric motor can be controllable by means of power electronics. The rotor can form a motor shaft of the electric motor. The drive train can have a pedal crankshaft, at which muscle power can be introduced into the drive train.The pedal crankshaft can be operatively connected to the output of the drive train. The drive train can have a gearbox. The gearbox can transmit drive force from the electric motor and the pedal crankshaft to the output. The output can be connected to one of the bicycle wheels, for example, by means of a chain or a belt. The gearbox can be arranged in a bottom bracket area on a bicycle frame. The electric motor can be arranged in the bottom bracket area on the bicycle frame. The electric motor can be arranged as a mid-engine on the bicycle. The electric motor can be at least partially accommodated in the interior of the housing. The gearbox can be at least partially accommodated in the interior of the housing. The housing can be sealed. For example, the interior can be an oil chamber. The oil can be used to lubricate the electric motor and, alternatively or additionally, the gearbox.The housing can, for example, be formed by the bicycle frame. However, the housing can also be formed by one or more separate components. For example, a stator of the electric motor is non-rotatably attached to the housing.

[0009] The sensor arrangement comprises a sensor, a transmitting unit, a receiving unit, and a feedthrough unit. In another embodiment, the sensor arrangement comprises only the sensor, and the transmitting unit, the receiving unit, and the feedthrough unit are optional. In another embodiment, the sensor arrangement comprises only the transmitting unit, and the sensor, the receiving unit, and the feedthrough unit are optional. In another embodiment, the sensor arrangement comprises only the receiving unit, and the transmitting unit, the sensor, and the feedthrough unit are optional. In another embodiment, the sensor arrangement comprises only the feedthrough unit, and the transmitting unit, the receiving unit, and the sensor are optional. The respective units of the sensor arrangement and also the sensor itself can therefore be optional.For example, the first aspect may only concern the integration of the transmitting unit and the sensor, the receiving unit and alternatively or additionally the implementation unit.

[0010] The sensor is connected to the rotor of the electric motor in a rotationally fixed manner. For example, the sensor is attached to the rotor. The sensor can be designed as a strain gauge, for example. The sensor can measure an operating variable of the electric motor or of the drive train in general, for example by detecting a deformation of the rotor. The deformation, usually strain, is caused, for example, by a torsional load caused by drive forces. The sensor can detect a variable that corresponds to a torque, a speed, and alternatively or additionally an angular position. For example, the sensor arrangement can detect a speed and, alternatively or additionally, a torque of the drive train, the electric motor, and alternatively or additionally, the crankshaft.The sensor's rotationally fixed connection to the rotor allows a relevant operating variable to be recorded directly and with minimal interference, for example, to control the electric motor and, alternatively or additionally, the transmission. The sensor can be located inside the housing, for example, together with the rotor.

[0011] The transmitting unit is designed to transmit a sensor signal to the receiving unit. The transmitting unit can have an antenna. The sensor signal can be generated by the sensor. For example, the sensor signal can be transmitted to the receiving unit wirelessly. This eliminates the need for a sliding contact to transmit the signal to a component stationary relative to the rotating rotor, which could significantly impair signal quality, require a lot of installation space, and cause additional resistance. The transmitting unit can be connected to the rotor of the electric motor without rotation. This makes transmitting the sensor signal from the sensor to the transmitting unit easy. For example, the sensor can be connected to the transmitting unit by a cable. This cable can be glued to the rotor for protection and fastening, or alternatively or additionally encapsulated. The transmitting unit can have a circuit board.The transmitter unit can be designed as a PCB, for example. The transmitter unit can be disc-shaped, for example. The transmitter unit can be a sensor electronics unit. The transmitter unit and, alternatively or additionally, the sensor can form an assembly with the rotor or even the entire electric motor, which can be mounted together, for example, in the housing.

[0012] The receiving unit can be attached to the housing in the interior. This allows the receiving unit to be protected. The receiving unit can be designed to receive the sensor signal. For example, the receiving unit can have an antenna. The receiving unit can be immobile relative to the housing. The receiving unit can have a power transmission device which is designed to wirelessly transmit power to the transmitting unit and alternatively or additionally to the sensor. For example, the receiving unit can inductively supply the transmitting unit with power via a coil. The sensor can be supplied with power via the transmitting unit. The receiving unit can have a circuit board. The receiving unit can be designed as a PCB, for example. The receiving unit can be disc-shaped, for example. The receiving unit can be a receiver electronics unit.The receiving unit can be mounted separately from the electric motor.

[0013] For example, the receiving unit can first be axially inserted through an access opening into the housing for assembly and secured. The transmitting unit and the electric motor can then be mounted through the same access opening. The transmitting unit can, for example, have a rotationally symmetrical basic shape or be designed to be rotationally symmetrical. The feedthrough unit is designed to provide an electrical interface to the receiving unit through the housing. The feedthrough unit can close the housing on one side. The feedthrough unit can be arranged at least partially in the housing. The interface can, for example, provide a connection to an inverter, power electronics, a control unit and, alternatively or additionally, to an evaluation unit of the drive train. The interface can, for example, be an electrical contact.The feedthrough unit is connected, for example, to the housing and alternatively or additionally to the receiving unit. The feedthrough unit can be attached to the housing, for example, to a through-opening. The through-opening may, for example, not be suitable for mounting the electric motor. The feedthrough unit can have a smaller extension in the circumferential direction than the receiving unit. For example, the receiving unit can extend completely around a rotational axis of the rotor, for example as an annular component. For example, the feedthrough unit can extend only over a small angular range and not form a ring.

[0014] The sensor arrangement can be compact, easy to install and enable secure and space-saving attachment of all components.

[0015] In a further embodiment of the sensor arrangement, it can be provided that the transmitting unit is fastened to the rotor at a distance from the sensor. For example, the transmitting unit can be fastened to the rotor axially and alternatively or additionally radially to the sensor. The transmitting unit and the sensor can, for example, be arranged without direct contact with one another. For example, the rotor can have an axial projection to which the transmitting unit is fastened, but not the sensor. This can reduce the influence of the transmitting unit on the measurement. For example, fastening the transmitting unit can locally stiffen the rotor so that a deformation measurement at the point where the transmitting unit is fastened no longer correctly corresponds to the operating variable. An electromagnetic field from the transmitting unit can also influence the sensor, which can be reduced by spacing it apart.This allows for particularly precise measurement of operating variables, while the transmitter unit and sensor form a compact assembly with the rotor, which can be easily mounted together. The transmitter unit and optionally also the sensor can be attached to a rotor cup. The rotor can have a cup and other components permanently connected to it for rotation. The transmitter unit and, alternatively or additionally, the sensor can be connected to the rotor without backlash.

[0016] In a further embodiment of the sensor arrangement, it can be provided that the transmitting unit is shear stress decoupled from a sensor region. The sensor region can be a region of the rotor at which the sensor measures. For example, the sensor region can be an area to which a sensor designed as a strain gauge is glued. Due to the shear stress decoupling, deformation of the rotor during operation can occur independently or almost independently of the transmitting unit. Shear stress influences from the transmitting unit on the sensor region can be decoupled. Such decoupling can be achieved, for example, by axial spacing, curvatures in the rotor between the transmitting unit and the sensor region, and through openings in the rotor between the transmitting unit and the sensor region. For example, an axial projection can bring about the decoupling.A soft and, alternatively or additionally, elastic attachment of the transmitter unit to the rotor can also achieve decoupling. For example, the transmitter unit can be hot-stamped to the rotor using plastic. A connecting component, which can be pin-shaped, for example, and is then caulked, can be softer than the circuit board and the rotor, allowing the connecting component to deform to decouple shear stress.

[0017] In a further embodiment of the sensor arrangement, the rotor may comprise a sheet metal part to which the sensor and the transmitter unit are attached. For example, the sheet metal part can be formed in a deep-drawing process. The sheet metal part can easily provide the spacing in the attachment and the decoupling of shear stress. Furthermore, the sheet metal part can be easily configured for various attachment methods for the transmitter unit, such as caulking. The sheet metal part can, for example, have a rotationally symmetrical basic shape or be rotationally symmetrical.

[0018] The sheet metal part can form a projection to which the transmitter unit is attached. The projection can extend axially, for example, in particular away from the sensor. The projection can form a through-hole to which the transmitter unit can be attached. The sheet metal part can have multiple through-holes. There can be one through-hole or multiple through-holes per projection. The through-hole can form a through-opening. The through-hole on the sheet metal part can serve, for example, to axially countersink a rivet head and as a spacer element for the transmitter unit. For example, three through-holes can be provided, which are arranged evenly spaced in the circumferential direction, for example. The position of the transmitter unit can be clearly defined by means of three through-holes. The transmitter unit can thus be attached in a torsion-free and stable manner.For example, the sensor is not attached to the projection. The sensor is arranged at a distance from the projection.

[0019] In a further embodiment of the sensor arrangement, the transmitter unit can be caulked to the rotor. For this purpose, the transmitter unit and the rotor can each have a through-hole in which a connecting part is arranged. The caulking can enable a play-free and preloaded connection. Furthermore, force transmission can be reduced by a suitable choice of material for the connecting part. For example, the connecting part can be made of plastic. For example, the transmitter unit can be hot-caulked to the rotor using plastic. The caulking can be carried out using a hot stamping die or infrared radiation.

[0020] Alternatively, the transmitter unit can be glued, screwed, riveted, or clipped to the rotor. It is also possible to mold the transmitter unit or encapsulate the transmitter unit with the rotor.

[0021] In a further embodiment of the sensor arrangement, it can be provided that the feedthrough unit seals with the housing. The feedthrough unit can, for example, form a plug or a cover for the housing. The feedthrough unit can have a base component and a sealing element. For example, an O-ring can be arranged as a sealing element between the base component and a wall of a through-opening of the housing in which the feedthrough unit is arranged. Other suitable seals are molded seals, lip seals, or seals injection-molded onto the base component. The base component can be a plastic component. However, sealing can also be achieved by gluing or injection-molding the base component to the housing. Due to the seal, the feedthrough unit can close and seal an oil chamber together with the housing.

[0022] In a further embodiment of the sensor arrangement, it can be provided that the feedthrough unit seals with the receiving unit. For example, the base component can be injection-molded or glued onto the receiving unit, so that a seal is created between the base component and the receiving unit. However, a further sealing element can also be provided between the base component and the receiving unit. For example, an O-ring can be arranged there. Other suitable seals here are also molded seals, lip seals, or seals molded onto the base component. The seal between the feedthrough unit and the receiving unit eliminates the need for sealing electrical contacts in the base component. For example, the base component can simply have a through-opening as an interface, through which respective electrical lines can be routed.

[0023] In a further embodiment of the sensor arrangement, it can be provided that the feedthrough unit has an electrical contact with the receiving unit as an interface. For example, an electrical contact can be cast into the base component of the feedthrough unit, which can be contacted on a side facing the interior or the receiving unit and a side facing away from the interior. The electrical contact can be sealed. This eliminates the need for a seal between the receiving unit and the feedthrough unit. The electrical contact can be accessible on a side facing away from the receiving unit. The electrical contact can extend through the base component.

[0024] In a further embodiment of the sensor arrangement, the feedthrough unit can have at least one through-opening as an interface. This makes it particularly easy for an electrical line or other element to contact the receiving unit. Furthermore, the feedthrough unit can be particularly lightweight. For example, the feedthrough unit is sealed to the receiving unit to prevent oil from escaping from the interior through the through-opening. This seal, together with the receiving unit, can, for example, separate the through-opening from the interior of the housing.

[0025] In a further embodiment of the sensor arrangement, it can be provided that the receiving unit is fastened to the housing with axial tension. This allows the receiving unit to be held in a predefined position without play. Accordingly, signal transmission can be particularly interference-free. The receiving unit can, for example, have a fastening element and a circuit board. The fastening element and the circuit board can be formed integrally or as separate components. For example, the receiving unit can be held to the housing with axial pretension by means of a clip, a plastic ring, an elastomer between the fastening part and the circuit board, a corrugated spring, a retaining ring, or a half-shell made of steel or plastic. The pretension can also be provided by an axial elasticity of the circuit board, for example by targeted weakening with holes.For example, the receiving unit can be arranged on a stop and alternatively or additionally a groove of the housing and can be pressed there axially in one direction by the fastening element.

[0026] In a further embodiment of the sensor arrangement, the receiving unit can be clipped onto the housing. For example, the receiving unit can form a snap connection with the housing. This clipping connection can make installation particularly easy. For example, the receiving unit can simply be pushed through the housing to its end position and click into place. This then eliminates the need to tighten very small screws with a very long screwdriver, which can be considerable trouble for an installer. The circuit board and, alternatively or additionally, the fastening element can, for example, have a rotationally symmetrical basic shape or be designed to be rotationally symmetrical. The fastening of the receiving unit can thus be self-centering.

[0027] In a further embodiment of the sensor arrangement, it can be provided that the feedthrough unit is attached to the receiving unit. The feedthrough unit and the receiving unit can form a common assembly. This assembly can be mounted together on the housing. For example, the feedthrough unit can be held in the through-opening of the housing via the receiving unit. The feedthrough unit can, for example, be glued, clipped, welded, screwed, or riveted to the receiving unit. The feedthrough unit can also be molded onto the receiving unit or caulked to the receiving unit.

[0028] A second aspect relates to a drive train for a bicycle. The bicycle can have the drive train. The drive train can be designed to transmit a drive force to a wheel of the bicycle. The drive train has an electric motor with a rotor and a housing with an interior space. The drive train has a sensor arrangement according to the first aspect. The sensor arrangement can be designed to detect an operating variable of the drive train. Respective further features, embodiments, and advantages can be found in the descriptions of the first aspect. Conversely, features, embodiments, and advantages of the second aspect also represent features, embodiments, and advantages of the first aspect.

[0029] Short description of the characters

[0030] Fig. 1 schematically illustrates a sensor arrangement for a drive train of a bicycle. Fig. 2 illustrates a schematic sectional view of the sensor arrangement according to Fig. 1.

[0031] Fig. 3 illustrates a schematic sectional view of another embodiment of a sensor arrangement.

[0032] Detailed description of embodiments

[0033] Fig. 1 shows a schematic diagram of a sensor arrangement for a drive train of a bicycle, with further details being shown in Fig. 2. The drive train has an electric motor with a rotor 10 and a housing 12 with an interior space. A stator of the electric motor is fastened to the housing 12. The sensor arrangement has a sensor 14 designed as a strain gauge, which is glued directly onto the rotor 10 and is thus fastened to the rotor 10 in a rotationally fixed manner. The sensor arrangement has a transmitting unit 16, which is fastened to the rotor 10 in a rotationally fixed manner by means of a connecting part 18 in the form of a clip or a hot-stitched pin via a spacer element that is connected to the rotor 10 in a rotationally fixed manner. The sensor 14 and its measuring area for a deformation of the rotor 10 are thus axially spaced from the transmitting unit 16. The connecting part 18 is also radially spaced from the sensor 14 and the measuring area.The transmitting unit 16 is shear stress-decoupled from the sensor area. The sensor 14 is connected to the transmitting unit 16 via an electrical line 20 for sensor signal transmission. The electrical line 20 is at least partially encapsulated with the transmitting unit 16 for protection.

[0034] The sensor arrangement further includes a receiving unit 22. The receiving unit 22 is rotationally fixed to the housing 12 by means of an adhesive. Furthermore, the housing 12 is electrically insulated from the receiving unit 22, here with an insulating varnish. An axial gap is formed between the receiving unit 22 and the transmitting unit 16. The transmitting unit 16 is configured to transmit the sensor signal to the receiving unit 22 wirelessly. The receiving unit 22 is configured to receive the sensor signal wirelessly and to supply wireless power to the transmitting unit 16 and the sensor 14 by means of induction.

[0035] The sensor arrangement has a feedthrough unit 24. The feedthrough unit 24 is arranged in a through-opening of the housing 12. The feedthrough unit 24 is designed to provide an electrical interface to the receiving unit 22 through the housing 12. In the example shown, the electrical interface connects the receiving unit 22 to a drive train ECU 26 arranged outside the interior of the housing 12. The rotor 10, the sensor 14, the transmitting unit 16, and the receiving unit 22 are arranged in the interior of the housing 12.

[0036] Fig. 2 shows a schematic sectional view of the drive assembly and the sensor assembly with further details in one embodiment. For example, a pedal crankshaft 42 is also shown, which extends through the housing 12.

[0037] As can be seen, the rotor 10 has a sheet metal part 40. The sheet metal part 40 forms three projections 44, evenly spaced in the circumferential direction, with a through-hole in the form of a through-opening. Each projection 44 extends in the axial direction towards the transmitting unit 16 and the receiving unit 22 away from the rest of the electric motor. A connecting part 18 is arranged in each of the through-holes, which in this case are designed as hot-stitched pins. A head of the connecting part 18 is countersunk in the projection 44. Another head of the connecting part 18 extends into the gap between the receiving unit 22 and the transmitting unit 16. This allows the

[0038] Projections 44 enable spacing and fastening of the transmitting unit 16, which requires less installation space than other fastening options, or at least is largely space-neutral in comparison. In addition, any influence on the measurement of the operating variable by the transmitting unit 16 and its fastening to the rotor 10 is avoided. The transmitting unit 16 is permanently connected to the rotor 10 without play. Fig. 2 also shows that the receiving unit 22 has a fastening element 46 and a disc-shaped and ring-shaped circuit board 48. The fastening element 46 is clipped radially inward into a groove of the housing 12 and is also ring-shaped here. For example, the fastening element 46 is formed integrally with the circuit board 48 and is shaped by radially inwardly projecting elastic teeth. These bear against the housing 12 or the groove. The fastening element 46 clamps the receiving unit 22 orthe circuit board 48 advances axially in a direction away from the transmitting unit 16. This achieves a defined position and the gap between the receiving unit 22 and the transmitting unit 16 can be small despite the vibrations when riding a bicycle. However, the circuit board 48 can also be elastic for this purpose in one embodiment, for example through targeted weakenings in the form of openings and recesses. Furthermore, the circuit board 48 can bear against the housing 12 in some embodiments. The fastening element 46 is designed as an elastic plastic injection-molded ring, which is injection-molded onto the circuit board 48. In other embodiments, the fastening element 46 can be designed as a corrugated spring, retaining ring, or half-shell.

[0039] The feedthrough unit 24 is permanently connected to the receiving unit 22. This forms an assembly that can be inserted into the housing 12 and secured thereto.

[0040] Fig. 2 shows the feedthrough unit 24 in further detail. The feedthrough unit 24 has a base component 50, which is designed as an injection-molded plastic shell. The base component 50 is molded onto the receiving unit 22 here. In other embodiments, the base component 50 is connected to the receiving unit 22 in a different way, such as by clipping. In this embodiment, the interface is a plurality of electrical contacts molded into the base component 50. The base component 50 is partially arranged in the through-opening of the housing 12. Radially outward, the base component 50 has an O-ring 52 as a sealing element, which seals the feedthrough unit 24 to the housing 12. Since the contacts are also tightly integrated into the base component 50, the feedthrough unit 24 closes the housing 12 in an oil-tight manner, providing electrical access.

[0041] In Fig. 2 it can be seen that the ECU 26 is protected by a cover 54 which is sealingly connected to the housing 12.

[0042] Fig. 3 shows a further embodiment of the sensor arrangement. The section is oriented differently, so that no projection 44 and no attachment of the transmitting unit 16 is shown. Significant differences in the third embodiment relate to the feedthrough unit 24. This now has a molded-on sealing lip 60 instead of an O-ring 52 for sealing with the housing 12. In this embodiment, the base component 50 is also sealingly connected to the receiving unit 22. On a side facing the feedthrough unit 24, an intermediate space is thus formed, which is sealed off from the interior of the housing 12. For this purpose, the receiving unit 22 is caulked to the base component 50 in the embodiment shown. Here, too, a connecting component 62 is provided for the caulking, which also seals between the receiving unit 22 and the base component 50.Alternatively, an additional sealing element, such as an O-ring, can be provided. Sealing by gluing or injection molding the base component 50 is also a possible embodiment.

[0043] The base component 50 has a through-hole 64 for electrical contacts or electrical lines leading to the intermediate space. These through-holes 64 are not sealed, since the intermediate space is already sealed from the interior. The electrical lines can then simply be soldered to the receiving unit 22. Instead of multiple through-holes 64, the base component 50 can also be designed as a ring, thus forming a central through-hole. Reference symbol

[0044] rotor

[0045] Housing

[0046] sensor

[0047] Transmitter unit

[0048] connecting part

[0049] Line

[0050] Receiving unit

[0051] Implementation unit

[0052] ECU

[0053] Sheet metal forming part

[0054] crankshaft

[0055] projection

[0056] Fastening element

[0057] circuit board

[0058] Basic component

[0059] O-ring

[0060] Lid

[0061] sealing lip

[0062] Connecting component

[0063] passage opening

Claims

Patent claims 1. Sensor arrangement for a drive train of a bicycle, wherein the drive train has an electric motor with a rotor (10) and a housing (12) with an interior space, wherein the sensor arrangement has a sensor (14), a transmitting unit (16), a receiving unit (22) and a feedthrough unit (24), wherein the sensor (14) and the transmitting unit (16) are connected in a rotationally fixed manner to the rotor (10) of the electric motor, wherein the transmitting unit (16) is designed to transmit a sensor signal to the receiving unit (22), wherein the receiving unit (22) is fastened to the housing (12) in the interior space, and wherein the feedthrough unit (24) is designed to provide an electrical interface (24) to the receiving unit (22) through the housing (12).

2. Sensor arrangement according to claim 1, characterized in that the transmitting unit (16) is attached to the rotor (10) at a distance from the sensor (14).

3. Sensor arrangement according to claim 1 or 2, characterized in that the transmitting unit (16) is shear stress decoupled from a sensor area.

4. Sensor arrangement according to one of the preceding claims, characterized in that the rotor (10) has a sheet metal formed part (40) to which the sensor (14) and the transmitting unit (16) are fastened, wherein the sheet metal formed part (40) forms a projection (44) to which the transmitting unit (16) is fastened.

5. Sensor arrangement according to one of the preceding claims, characterized in that the transmitting unit (16) is caulked to the rotor (10).

6. Sensor arrangement according to one of the preceding claims, characterized in that the feedthrough unit (24) seals with the housing (12).

7. Sensor arrangement according to one of the preceding claims, characterized in that the feedthrough unit (24) seals with the receiving unit (22).

8. Sensor arrangement according to one of the preceding claims, characterized in that the feedthrough unit (24) has an electrical contact with the receiving unit (22) as an interface.

9. Sensor arrangement according to one of the preceding claims 1 to 7, characterized in that the feedthrough unit (24) has at least one through opening (64) as an interface.

10. Sensor arrangement according to one of the preceding claims, characterized in that the receiving unit (22) is fastened to the housing (12) with an axial tension. 1 1. Sensor arrangement according to one of the preceding claims, characterized in that the receiving unit (22) is clipped onto the housing (12).

12. Sensor arrangement according to one of the preceding claims, characterized in that the feedthrough unit (24) is attached to the receiving unit (22).

13. Drive train for a bicycle, the drive train comprising an electric motor with a rotor (10), a housing (12) with an interior space and a sensor arrangement according to one of the preceding claims.

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