Steering gear with position sensor system and electric steering system with the steering gear

Abstract

A steering gear (4) for an electric steering system (1) is proposed, with a gear housing (16), with a transmission shaft (14) which is mounted rotatably in the gear housing (16), wherein the transmission shaft (14) has an input interface (18) for attaching an electric drive motor (10), with an output shaft (6) which is mounted rotatably in the gear housing (16), wherein the output shaft (6) has an output interface (19) for attaching to a steering linkage, with a transmission gear (15) which is connected to the output shaft (6) fixedly for conjoint rotation, wherein the transmission gear (15) is in meshing engagement with the transmission shaft (21) for the transmission of a steering movement from the transmission shaft (14) to the output shaft (6), wherein the steering gear (4) has a position sensor system (13) with at least one position sensor (22) for the contactless detection of a position of the transmission gear (15), wherein a detection region of the position sensor (22) is arranged within the gear housing (16).

Description

[0001] Steering gear with position sensors and electric steering system with the

[0002] steering gear

[0003] The invention relates to a steering gear for an electric steering system having the features of the preamble of claim 1. Furthermore, the invention relates to an electric steering system with the steering gear.

[0004] Steering systems for vehicles are known that implement power assistance for an applied actuating torque using the torque of a servo motor. For this purpose, a worm gear or a recirculating ball gear is used, for example, as a steering gear, which serves to transmit the actuating torque and the torque to one or more vehicle wheels. The relationship between the steering wheel angle and the actual wheel steering angle of the steered vehicle wheels depends on the transmission path of the steering movement from the steering wheel to the vehicle wheels and on the arrangement of the sensors within the steering system.

[0005] For example, the document DE 10 2004 006 835 A1 discloses an electrohydraulic steering system for a vehicle, comprising a steering spindle that connects a steering handle at one end to a rotary slide or rotary piston of a steering valve via a first torsion element, and a hydraulic servomotor for actuating an output member of a steering gear, wherein a pressure medium flow into the working chambers of the hydraulic servomotor is controlled by the steering valve. The steering system also has an electric servomotor for actuating the output member, wherein the electric servomotor and the steering spindle act on a common rotary member between the first torsion element and the rotary slide or rotary piston.The electric servomotor is controlled via a control and / or regulating device of the steering system or the vehicle, depending on signals from a rotation angle sensor that detects a rotation angle and / or an actuation torque on the steering handle. The object of the invention is to create a steering gear of the type mentioned above, which is characterized by more precise and robust detection of the wheel steering angle.

[0006] This object is achieved according to the invention by a steering gear having the features of claim 1 and a steering system having the features of claim 12. Advantageous embodiments emerge from the subclaims, the drawings and / or the description.

[0007] The subject matter of the invention is a steering gear designed and / or suitable for an electric steering system. In particular, the steering gear serves to transmit a steering movement to one or more vehicle wheels of a vehicle.

[0008] The steering gear comprises a gear housing, with a transmission shaft and an output shaft rotatably mounted within the gear housing. In particular, the transmission shaft and the output shaft are aligned transversely to each other. In other words, the transmission shaft defines a first axis of rotation, and the output shaft defines a second axis of rotation, with the two axes of rotation intersecting, in particular at right angles, in a plan view.

[0009] The transmission shaft has an input interface which is designed and / or suitable for transmitting a steering movement generated by an electric drive motor. The input interface can be designed as a shaft journal protruding from the end of the transmission housing, to which the drive motor is connected for drive purposes, preferably for transmitting torque. In principle, the steering movement can be implemented exclusively by the electric drive motor or transmitted to the transmission shaft. Optionally, the input interface can be connected to a steering spindle or steering column in order to transmit an actuating torque applied by a steering handle, in particular a steering wheel, to the transmission shaft. The electric drive motor thus serves as an electric servo motor for steering force assistance.The output shaft has an output interface, which is designed and / or suitable for transmitting a steering movement to one or more, preferably two, vehicle wheels. The output interface can be designed as a further shaft journal protruding from the end of the transmission housing, which is connected to the at least one vehicle wheel via known kinematic connections in order to change a wheel steering angle on the vehicle wheel upon rotation of the output shaft.

[0010] The steering gear has a transmission gear connected to the output shaft in a rotationally fixed manner, which transmission gear engages the transmission shaft to transmit the steering movement from the transmission shaft to the output shaft. In particular, the transmission gear converts a rotational movement of the transmission shaft about the first axis of rotation into a rotational movement of the output shaft about the second axis of rotation. The steering gear can be designed as a worm gear or as a recirculating ball gear. In principle, the output shaft and the transmission gear can be formed from a common section of material. Alternatively, the transmission gear is designed separately from the output shaft, wherein the transmission gear is connected to the output shaft at least in the circumferential direction in a form-fitting and / or force-fitting and / or material-fitting manner.

[0011] Within the scope of the invention, it is proposed that the steering gear have a position sensor system with at least or exactly one position sensor, which is designed and / or suitable for contactless detection of a position of the transmission wheel, wherein a detection range of the position sensor is arranged within the gear housing. In particular, the transmission wheel is arranged within the detection range such that a position of the transmission wheel can be detected continuously over its entire working path by the position sensor. In particular, the detection range is to be understood as the range in which the position sensor can detect a position of the transmission wheel without impairment and / or directly. A position can be understood as both an absolute position of the transmission wheel and a change in the position of the transmission wheel.In particular, the position sensor is designed to transmit the detected position of the transmission wheel as position information to a control unit which is designed to determine an actual wheel steering angle of the vehicle wheels on the basis of the position information and / or to take the position information into account when determining a desired wheel steering angle.

[0012] The invention is based on the finding that due to backlash and hysteresis effects of the steering system in conjunction with the gear ratio of the steering gear, the necessary determination of the wheel steering angle of the vehicle wheels is impaired or inaccurate. Thus, precise steering is no longer guaranteed, particularly for safety-critical applications such as steer-by-wire or autonomous driving, where the exact position of the steered wheels or the exact wheel steering angle is required.

[0013] By directly detecting the position of the transmission gear, precise position detection on the output side of the steering gear and thus precise determination of the wheel steering angle of the vehicle wheels can be ensured. By detecting the position of the transmission gear on the output side of the steering gear, the backlash and hysteresis effects when determining the wheel steering angle can be significantly reduced. A further advantage is that by arranging the position sensor or the detection area in the gear housing, a particularly robust sensor system can be proposed, which is protected by the gear housing from external influences such as moisture, dirt, mechanical impacts, electrical or electromagnetic effects, etc. Furthermore, a particularly compact steering gear with integrated position sensors can be realized.

[0014] In a first embodiment, the position sensor is designed as an angular position encoder, in particular as a rotary encoder. In particular, the position sensor serves to detect a rotation angle and / or a change in the rotation angle of the transmission wheel during rotation about the second rotational axis. For this purpose, the transmission wheel is rotated relative to the position sensor within the detection range, with the position sensor remaining stationary. The rotary encoder can optionally be designed as an absolute encoder for detecting an absolute rotation angle or as an incremental encoder for detecting a relative rotation angle. Thus, a position sensor is proposed which is characterized by simple and precise position detection of the transmission wheel.

[0015] In a further specific embodiment, the position sensor is designed as a magnetic and / or inductive and / or capacitive and / or acoustic and / or optical and / or resistive position sensor, in particular a rotary encoder. In particular, the magnetic position sensor has a magnetically sensitive sensor element, wherein the transmission wheel causes a change in a magnetic field depending on the angle of rotation, which change is detectable by the sensor element. For example, the magnetic position sensor can be designed as a Hall sensor. In particular, the inductive position sensor has at least one electrical coil, wherein the transmission wheel causes a different inductance of the at least one coil depending on the angle of rotation.In particular, the capacitive position sensor comprises a rotor element connected to the transmission wheel in a rotationally fixed manner, as well as at least one stationary, electrically conductive stator element, wherein the transmission wheel causes a different capacitance of the at least one stator element depending on the angle of rotation. In particular, the different sensor types or measuring principles can also be combined with one another. Thus, a position sensor system is proposed that is characterized by particularly robust and reliable position detection.

[0016] In one possible implementation, it is provided that the position sensor is arranged in the transmission housing at a distance from the transmission gear in the axial direction with respect to the second axis of rotation of the output shaft. In particular, the position sensor is arranged on an axial end face of the transmission gear. An axial air gap is preferably formed between the position sensor and the transmission gear. This enables particularly simple integration or arrangement of the position sensor in the transmission housing. In an alternative implementation, it is provided that the position sensor is arranged in the transmission housing at a distance from the transmission gear in the radial direction with respect to a rotational axis of the output shaft. In particular, the position sensor is arranged on a radial outer side of the transmission gear. A radial air gap is preferably formed between the position sensor and the transmission gear.This enables a particularly compact and space-saving integration or arrangement of the position sensor in the gearbox housing.

[0017] In a further specific embodiment, the position sensor system comprises a sensor target arranged on the transmission wheel and / or integrated into the transmission wheel for contactless detection by the position sensor. The sensor target can be designed as a magnetic and / or magnetizable sensor target. Preferably, the sensor target is designed as a permanent magnet for generating the magnetic field. Alternatively, the sensor target is designed as a measuring embodiment. The measuring embodiment serves, in particular, to reproduce relative or absolute position information, which can be detected by the position sensor by scanning. The measuring embodiment can comprise a single- or multi-track incremental or absolute coding. In particular, the measuring embodiment can be scanned magnetically and / or optically and / or electrically and / or acoustically, with the position sensor being designed accordingly.In an axial arrangement, the sensor target is preferably arranged on the axial end face of the transmission wheel. In a radial arrangement, the sensor target is preferably arranged on the radial outer side of the transmission wheel. The sensor target can extend at least partially in the circumferential direction. Preferably, the sensor target is annular or at least partially annular around the second rotational axis. Thus, a position sensor system is proposed that is characterized by secure and reliable detection of the rotation angle.

[0018] In a further possible embodiment, it is provided that the transmission wheel is designed as a gear with a toothing geometry, wherein the position sensor is designed and / or suitable for contactless detection of the toothing geometry. In particular, the toothing geometry is designed in sections in the circumferential direction, wherein the toothing geometry meshes with a counter-toothing, in particular a helical, set of teeth on the transmission shaft over a limited angular range. Alternatively, however, the toothing geometry can also be designed to run circumferentially. For scanning the toothing geometry, the position sensor is aligned either in the axial direction towards the end face of the toothing geometry or in the radial direction towards the head of the toothing geometry. For example, the position sensor can be designed as a gear encoder.This allows for particularly simple and cost-effective detection of the transmission wheel position.

[0019] In a specific development, it is provided that the gearing geometry is designed as a segment gearing. In particular, the gearing geometry extends in the circumferential direction over an angular range of more than 90 degrees, preferably more than 180 degrees. The sensor target can be arranged optionally within the angular range of the gearing geometry or outside the angular range of the gearing geometry, in particular in a gear-free section of the transmission gear. In particular, the transmission gear and the output shaft can be designed together as a segment shaft. Alternatively, the transmission gear can be designed as a transmission gear segment that is connected in a rotationally fixed manner to the output shaft. Thus, a particularly compact and space-saving design of the steering gear is proposed.

[0020] In a further embodiment, the position sensor system is of modular construction, wherein the position sensor is and / or is replaced by at least one other position sensor depending on the resolution and / or accuracy of the position detection. For this purpose, the position sensor is preferably replaceable, in particular detachable, attached to or in the transmission housing and / or connected to a signal line via a plug connection. In particular, the position sensor and the at least one further position sensor can be designed differently with regard to sensor type and / or measurement accuracy and / or measurement principle. Thus, a position sensor system is proposed which is characterized by the simple implementation of different position sensors and, if necessary, the simple and needs-based retrofitting of the steering gear with a position sensor suitable for the application.

[0021] In a further specific embodiment, it is provided that at least the position sensor is mounted in the transmission housing so as to be accessible from the outside. In particular, the position sensor can be mounted via a sensor interface formed in the transmission housing, e.g. an opening, such that at least the detection range of the position sensor is arranged within the housing or the transmission wheel is arranged within the detection range. The position sensor can be fixed to the transmission housing, for example, via a releasable fastening in a form-fitting and / or force-fitting manner, e.g. via a screw, clip or plug connection, etc. The position sensor is preferably arranged in a sealing, preferably fluid-tight manner, via a seal on the housing, in particular the sensor interface. A position sensor system is thus proposed which is easily accessible in the event of maintenance.In addition, the position sensor can be easily replaced if damaged.

[0022] In a further development, the position sensor system is designed redundantly. In particular, the position sensor system, in particular the position sensor, is designed to meet the requirements, particularly those of ASIL A, B, C, or D, according to ISO 26262. Specifically, the position sensor system can have at least one additional position sensor arranged in the transmission housing for independent position detection of the transmission gear. Thus, a position sensor system is proposed that is characterized by high operational reliability and is suitable for use in safety-critical applications.

[0023] Another subject of the invention relates to an electric steering system for a vehicle with the steering gear as already described above. In particular, the electric steering system serves to electrically, in particular electromechanically, implement a steering command generated by a steering handle to at least one steerable vehicle wheel. The vehicle can in principle be a passenger car (car), an agricultural or construction machine. The vehicle is preferably a commercial vehicle (CV). In a preferred embodiment, the electric steering system is designed as an electric power steering system (EPS). In particular, the electric power steering system has an electric servo motor for steering assistance.During a steering operation, a steering angle is specified by the steering handle as a measure of the desired wheel steering angle for the at least one steerable wheel, with the electric servomotor providing additional torque for steering assistance. In particular, the electric servomotor is drive-connected to the transmission shaft, in particular the input interface, for this purpose.

[0024] In a further specific embodiment, the output shaft is connected to a steering linkage via a pitman arm, also known as a Pitman arm, in order to change the steering angle of at least one vehicle wheel upon rotation of the output shaft. In particular, the pitman arm is designed to convert a rotational movement of the output shaft into a linear movement of the steering linkage, in particular a steering rod or a tie rod. The steering rod or tie rod can be connected to the respective vehicle wheel to be steered via a tie rod.

[0025] In a specific implementation, the steering system comprises an electric drive motor, in particular an electric servo motor, which is drive-connected to the transmission shaft, and a control unit (ECU), wherein the control unit is configured to control and / or regulate the drive motor based on a position of the transmission wheel detected by the position sensor system. In particular, the position sensor is connected to the control unit via signals. In principle, the position sensor is connected to the control unit, in particular a vehicle control unit, via a BUS system, e.g., a LIN bus. Alternatively, the position sensor can be directly connected to the control unit, in particular a steering control unit, via a signal line.The control unit preferably has an evaluation unit configured to evaluate position information of the transmission wheel transmitted by the position sensor and / or to consider it when determining the wheel steering angle. Specifically, the control unit is configured to determine the actual wheel steering angle and / or target wheel steering angle for the at least one vehicle wheel based on the position information and steering information, such as actuation torque, steering angle, etc., of the steering handle.

[0026] Further features, advantages, and effects of the invention will become apparent from the following description of preferred embodiments of the invention. These show:

[0027] Figure 1 is a schematic representation of an electric steering system as an embodiment of the invention;

[0028] Figure 2 is a sectional view of a steering gear with a position sensor for the steering system from Figure 1;

[0029] Figure 3 shows the steering gear in the same representation as Figure 2 with an alternative design of the position sensor;

[0030] Figure 4 shows the steering gear in the same representation as Figure 2 with another alternative design of the position sensor.

[0031] Figure 1 shows a highly simplified representation of an electric steering system 1 for a vehicle, in particular for a commercial vehicle. The electric steering system 1 is designed as an electric power steering system.

[0032] The steering system 1 has a steering handle 2 designed as a steering wheel, which is connected to a steering gear 4 via a steering column 3. The steering gear 4 serves to adjust a wheel steering angle of at least one steerable vehicle wheel 5 of the vehicle as a function of a rotation of the steering column 3. For this purpose, an output shaft 6 of the steering gear 4 is connected to a steering rod 8 via a steering column arm 7, wherein a rotary movement of the output shaft 6 is converted via the steering column arm 7 into a linear movement of the steering rod 8. The steering rod 8 is in turn connected to the vehicle wheel 5 to be steered via a steering lever 9 in order to adjust the corresponding wheel steering angle on the vehicle wheel 5.

[0033] Furthermore, the steering system 1 comprises an electric drive motor 10 and an electronic control unit 11 for controlling and / or regulating the drive motor 10. The electric drive motor 10 is designed as an electric servomotor, which is gear-coupled to the steering gear 4 to apply additional torque. For example, the drive motor 10 and the steering column 3 can jointly act on an input shaft (not shown) of the steering gear 6.

[0034] The steering system 1 has a drive-side steering sensor system 12, which supplies corresponding sensor data to the control unit 11 to detect a steering command and is evaluated in the control unit 11. The steering sensor system 12 serves, for example, to detect an actuation torque and / or a steering angle on the steering column 3, which are transmitted to the control unit 11 as sensor data.

[0035] In order to set an exact wheel steering angle of the vehicle wheel 5 for special driving applications, such as steer-by-wire or autonomous driving, precise detection of the wheel steering angle is required. This is not guaranteed by the arrangement of the steering sensors 12 near the steering column 3 due to mechanical play and hysteresis effects from the steering column 3 to the vehicle wheel 5.

[0036] The steering system 1 therefore has an additional position sensor 13, which is arranged on the output side of the output shaft 6 in order to detect a position of the output shaft 6, in particular a rotation angle. The position sensor 13 is designed to provide the detected position as position information to the control unit 11, wherein the control unit 11 is designed to take the position information into account when determining the wheel steering angle and / or to correlate it with the sensor data of the steering sensor 12. The structure of the position sensor 13 depends on the respective sensor principle as well as the required accuracy and resolution that must be achieved. The position sensor 13 is also designed as a fault-tolerant, redundant system with a high ASIL classification, e.g. ASIL-C or ASIL-D.

[0037] Figures 2 to 4 each show the steering gear 4 in a sectional view with different arrangement options for the integrated position sensor 13. In the respective exemplary embodiment, the steering gear 4 is designed as a worm gear, wherein a transmission shaft 14 designed as the input shaft in the form of a worm shaft meshes via a transmission gear 15 which is connected in a rotationally fixed manner to the output shaft 6 and is designed as a worm gear.

[0038] The steering gear 4 has a gear housing 16, wherein the transmission shaft 14 is mounted in the gear housing 16 for rotation about a first axis of rotation 100 and the output shaft 6 is mounted for rotation about a second axis of rotation 101. For this purpose, the transmission shaft 14 is rotatably supported in the gear housing 16 via two bearing devices 17. In a plan view, the first and second axes of rotation 100, 101 are aligned transversely and at right angles to each other, respectively.

[0039] The transmission shaft 14 has an input interface 18 which leads out of the transmission housing 16 and serves to mechanically connect the electric drive motor 10 in order to transmit the torque via the transmission shaft 14 to the transmission gear 15 and thus to the output shaft 6 by means of the drive motor 10. The input interface 18 is formed, for example, by a shaft journal which has a form-fitting contour, e.g. a spline. Accordingly, the output shaft 6 has an output interface 19, as shown in Figure 1, which serves to mechanically connect the steering column arm 7 in order to transmit the torque or the steering movement from the output shaft 6 to the steering train. The transmission gear 15 has a toothing geometry 20 on its circumference which extends over an angular range of approximately 180 degrees and engages with a corresponding counter-toothing 21 of the transmission shaft 14.For example, the transmission gear 15 is designed as a transmission gear segment. When the transmission shaft 14 rotates about the first rotational axis 100, the transmission gear 15 and thus the output shaft 101 are rotated within the angular range about the second rotational axis 101.

[0040] The position sensor system 13 has a position sensor 22 and a sensor target 23 that can be detected by the position sensor 22. The sensor target 23 can be integrated into the transmission wheel 15 or connected to it in a rotationally fixed manner, or derived from the external design of the transmission wheel 15. The position sensor 22 is arranged opposite the sensor target 23 and remains stationary when the transmission wheel 15 rotates. The position sensor 22 is arranged in the gear housing 16 such that a detection range of the position sensor is arranged within the gear housing 16. Position detection thus takes place within the gear housing 16 in the region of the transmission wheel 15, so that the detection range is protected from external influences, e.g., contamination, mechanical effects, electromagnetic waves, etc.For example, the position sensor 22 can be designed for inductive, capacitive or magnetic detection of the sensor target 23, wherein the sensor target 23 is designed accordingly for this purpose.

[0041] In the illustrated embodiment, the sensor target 23 can be formed, for example, by a partially annular permanent magnet extending around the second axis of rotation 101 for generating a magnetic field. In this case, the position sensor 22 would be designed as a magnetic field sensor, in particular a Hall sensor, which detects a relative or absolute position of the transmission wheel 15 during rotation about the second axis of rotation 101 by means of a change in the magnetic field. For this purpose, the sensor target 23 extends circumferentially around the second axis of rotation 101 over an angular range between 100 degrees and 170 degrees. The position sensor 22 thus directly detects the position of the transmission wheel 15 and thereby bypasses all mechanical error influences of the steering gear 4, thereby enabling particularly precise detection of the wheel steering angle.As explained above, a different type of sensor measuring principle can also be applied at this point according to the invention.

[0042] As shown in Figure 2, the sensor target 23 is arranged on an axial end face of the transmission wheel 15 in the angular range of the toothing geometry 20, wherein the position sensor 22 is arranged offset or spaced from the sensor target 23 in the axial direction with respect to the second axis of rotation 101.

[0043] As shown in Figure 3, the sensor target 23 is arranged on the axial end face of the transmission wheel 15 outside the angular range of the gear geometry 20 or in the radial direction opposite the gear geometry 20, wherein the position sensor 22 is arranged offset in the axial direction with respect to the second axis of rotation 101 or at a distance from the sensor target 23.

[0044] As shown in Figure 4, the sensor target 23 is arranged on a radial outer side of the transmission wheel 15 in the angular range of the toothing geometry 20, wherein the position sensor 22 is arranged offset or spaced from the sensor target 23 in the radial direction with respect to the second axis of rotation 101.

[0045] For example, the arrangements of the position sensor 22 and the sensor target 23 can be combined to form a redundant position sensor system 13 with at least two independently detected positions of the transmission wheel 15. For example, it is possible to arrange a second, redundant position sensor and / or a second, redundant sensor target according to Figure 3 in addition to the arrangement of the position sensor 22 and the sensor target 23 according to Figure 2, wherein the sensors can use different measuring methods and / or be positioned at different locations.

[0046] Steering system

[0047] steering handle

[0048] steering column

[0049] steering gear

[0050] vehicle wheel

[0051] Output shaft

[0052] Steering column lever

[0053] handlebar

[0054] Track lever

[0055] drive motor

[0056] control unit

[0057] Steering sensors

[0058] Position sensor

[0059] transmission shaft

[0060] transmission wheel

[0061] Gearbox housing

[0062] Storage facility

[0063] Input interface

[0064] Output interface

[0065] Gear geometry

[0066] Counter-toothing

[0067] Position sensor

[0068] Sensor target first rotation axis second rotation axis

Claims

Patent claims 1. Steering gear (4) for an electric steering system (1), comprising a gear housing (16), a transmission shaft (14) rotatably mounted in the gear housing (16), the transmission shaft (14) having an input interface (18) for connecting an electric drive motor (10), an output shaft (6) rotatably mounted in the gear housing (16), the output shaft (6) having an output interface (19) for connecting to a steering linkage, a transmission gear (15) connected in a rotationally fixed manner to the output shaft (6), the transmission gear (15) meshingly engaging with the transmission shaft (21) for transmitting a steering movement from the transmission shaft (14) to the output shaft (6), characterized by a position sensor system (13) having at least one position sensor (22) for contactless detection of a position of the transmission gear (15),wherein a detection area of ​​the position sensor (22) is arranged within the transmission housing (16).

2. Steering gear (4) according to claim 1, characterized in that the position sensor (22) is designed as an angular position sensor, in particular as a rotary sensor.

3. Steering gear (4) according to claim 1 or 2, characterized in that the position sensor (22) is designed as a magnetic and / or inductive and / or capacitive and / or acoustic and / or optical and / or resistive sensor.

4. Steering gear (4) according to one of the preceding claims, characterized in that the position sensor (22) is arranged in the gear housing (16) at a distance from the transmission gear (15) in the axial direction with respect to a rotational axis (101) of the output shaft (6).

5. Steering gear (4) according to one of claims 1 to 3, characterized in that the position sensor (22) is arranged in the gear housing (16) at a distance from the transmission gear (15) in the radial direction with respect to a rotational axis (101) of the output shaft (6).

6. Steering gear (4) according to one of the preceding claims, characterized in that the position sensor system (13) has a sensor target (23) arranged on the transmission wheel (15) and / or integrated in the transmission wheel (15) for contactless detection by the position sensor (22).

7. Steering gear (4) according to one of the preceding claims, characterized in that the transmission wheel (15) has a toothing geometry (20), wherein the position sensor (22) is designed for contactless detection of the toothing geometry (20).

8. Steering gear (4) according to claim 7, characterized in that the toothing geometry (20) is designed as a segment toothing.

9. Steering gear (4) according to one of the preceding claims, characterized in that the position sensor system (13) is of modular construction, wherein at least the position sensor (22) is interchangeable by at least one other position sensor depending on the resolution and / or the accuracy of the position detection.

10. Steering gear (4) according to one of the preceding claims, characterized in that at least the position sensor (22) is mounted in the gear housing (16) so as to be accessible from the outside.

11. Steering gear (4) according to one of the preceding claims, characterized in that the position sensor system (13) is constructed redundantly.

12. Electric steering system (1) for a vehicle, with the steering gear (4) according to one of the preceding claims.

13. Electric steering system (1) according to claim 12, characterized in that the electric steering system (1) is designed as an electric power steering system (EPS).

14. Electric steering system (1) according to claim 12 or 13, characterized in that the output shaft (6) is connected to a steering linkage via a steering column lever (7) in order to change a wheel steering angle of at least one vehicle wheel (5) upon rotation of the output shaft (6).

15. Electric steering system (1) according to one of claims 12 to 14, characterized in that the steering system (1) has an electric drive motor (10) which is drive-technically connected to the transmission shaft (14) and a control unit (11), wherein the control unit (11) is designed to control and / or regulate the drive motor (10) on the basis of a position of the transmission wheel (15) detected by the position sensor system (13).

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