Device for securing position

Abstract

A device (40) for securing the position of a rotation angle sensor (9) determining a rotation angle between a rotor and a stator relative to a sensor carrier about a rotation axis (8) is disclosed, comprising: - a basic body (48), - a torsionally stiff retaining bearing (52) viewed in the circumferential direction (44) around the axis of rotation (8) for absorbing a torsional force from the rotation angle sensor (9), and - a spring (50) held on the retaining bearing (52), which is arranged to apply a restoring force to the sensor carrier, with at least one spring foot (56) and a spring arm (54) extending at least partially axially (42) with respect to the axis of rotation (8), which, viewed in the circumferential direction (44) around the axis of rotation (8), comprises a forward-oriented spring arm side (58) and a rearward-oriented spring arm side (60) opposite the forward-oriented spring arm side, characterized in that - the spring foot (56) and at least one of the spring arm sides (58, 60) are arranged within the base body (48).

Description

[0001] The present invention relates to a device for securing the position according to the preamble of claim 1.

[0002] Such a device is known from DE 10 2022 103 722 A1.

[0003] From DE 10 2012 105 966 ​​A1, which the aforementioned DE 10 2022 103 722 A1 references via EP 2 870 054 A1, a rotary angle sensor for determining a relative angular position is known, comprising a housing, at least one rotor, a circuit board, and stator(s). The housing is secured against rotation by a connecting component. To achieve backlash-free rotation protection with simple assembly under all operating conditions, a plastic spring of the connecting component is supported by a metal spring.

[0004] The purpose of the invention is to improve the known device.

[0005] The problem is solved by the features of the independent claims. Preferred further developments are the subject of the dependent claims.

[0006] Starting from a device for securing the position of a rotary angle sensor determining a rotation angle between a rotor and a stator relative to a sensor carrier about an axis of rotation, comprising a base body, a torsionally stiff retaining bearing viewed circumferentially about the axis of rotation for absorbing a torsional force from the rotary angle sensor, and a spring arranged to apply a restoring force to the sensor carrier, wherein the spring has at least one spring foot and a spring arm extending at least partially axially with respect to the axis of rotation, which in turn comprises, viewed circumferentially about the axis of rotation, a forward-facing spring arm side and, opposite the forward-facing spring arm side, a rearward-facing spring arm side, the spring foot and at least one of the spring arm sides are arranged within the base body according to the invention.

[0007] The described device is based on the premise that, in the aforementioned device for position securing, a spring arm is used whose spring base lies entirely outside the supporting housing or structural body. The spring arm is designed such that it has two opposite sides – one facing the base body and one facing away from it – so that the entire spring arm, including its point of attachment, is mounted circumferentially on the outside of the supporting structure. This arrangement results in an unfavorable stress distribution in the area of ​​the spring base, since the spring base is oriented circumferentially forward or backward around the axis of rotation, and the force transmission thus acts along the circumferential direction. Consequently, the material stress due to torsion of the spring base is concentrated on an internal V-shaped cutout between the spring arm and the base body.Repeated torsional stresses lead to material fatigue or cracking in the long term.

[0008] The proposed device addresses this issue by redesigning the direction of force application and the integration of the spring base in such a way that the material stress in the area of ​​the spring base is better distributed circumferentially around the torsional movement. According to the invention, this is achieved by arranging the spring base and at least one side of the spring arm within the base body, so that the spring arm is no longer attached circumferentially to the outside of the base body, but is instead axially integrated into the supporting structure. This orientation of the spring base towards the axis of rotation results in an improved distribution of mechanical stresses in the transition area between the spring arm and the base body at the spring base, where torsional forces are no longer introduced into the structure via a tangential contact path, but rather via an axially oriented clamping area.The axial alignment enables a more even distribution of force into a deeper material zone of the base body, thus significantly reducing local stress peaks in the area of ​​the spring base. Simultaneously, the integration into the base body creates a geometric guide that limits the movement of the spring arm and prevents overloading due to excessive deflection. An additional limiting wall is generally no longer necessary. The resulting clamping within the base body forms a more stable, directionally optimized load path, thus allowing for a stress-appropriate design of the anti-rotation device, which is not achievable with the known tangential connection in the aforementioned device.

[0009] By reducing stress peaks, material fatigue, and uncontrolled spring deflection exceedance in the area of ​​the spring base, the device according to the invention achieves significantly reduced failure rates during operation. The modified force transmission via an axially aligned spring base embedded within the base body leads to a more uniform stress distribution and, in particular, reduces the locally concentrated load peaks that have been identified as the cause of cracking or fractures in known designs. This has a positive effect on the fatigue strength of the entire component and extends its service life, even under cyclic or thermal loads. Furthermore, the geometric guidance of the spring arm within the base body ensures that the spring arm's travel remains controlled and that mechanical overloads due to excessive deflection are avoided.Overall, this results in a robust, series-stable solution with higher reliability, lower maintenance requirements and improved manufacturing tolerances, as the functionally critical load points are geometrically defined and structurally protected.

[0010] In a further development of the described device, the base body, viewed axially with respect to the axis of rotation, comprises a circumferential base body wall within which the spring arm is arranged. In this way, the spring arm can be completely enclosed by a load-bearing hollow structure, which not only enables secure and defined axial clamping but also provides geometric guidance and mechanical limitation of the spring arm. The circumferential wall allows the spring arm's range of motion to be precisely defined and mechanically prevents overloading due to excessive deflection. Furthermore, the surrounding base body wall reliably protects the spring arm from external influences such as dirt, mechanical contact, or thermal spikes.Furthermore, the hollow structure allows for space-optimized integration into existing housing designs and offers design freedom in the arrangement of multiple spring arms or sensor components. Manufacturing advantages also arise, as the wall structure can be produced particularly efficiently in a closed mold as a rotationally symmetrical or segmented injection-molded part.

[0011] In a further development, it is provided that the base body wall has a recess in the axial direction of the rotation axis, within which the spring arm is arranged. In this way, the spring arm is not only spatially guided within the base body, but is also supported by a laterally and / or axially limited structure, which enables precise and directionally defined guidance of the spring arm. The arrangement in a recess improves the structural integration of the spring arm, as the stresses from the spring arm can be transferred in a controlled manner into the surrounding wall structure and are not concentrated at a single point on an external connection. Furthermore, the geometry of the recess allows for a defined movement limit of the spring arm, which prevents unwanted excessive deflections and thus increases the service life of the component.The arrangement embedded in the wall structure simultaneously offers increased protection of the spring arm against mechanical damage or environmental influences and creates design freedom for further integration options, for example for the inclusion of additional guide or damping elements.

[0012] In a further advantageous embodiment, the spring base is arranged on the bottom side of the recess, viewed in the axial direction of the axis of rotation. In this way, the spring arm is introduced axially into the base structure from its base and anchored there over a flat area. The force is thus introduced along the axis of rotation into the wall depth of the recess, resulting in a particularly stable clamping with uniform stress distribution. The bottom-side embedding allows for the efficient transfer of bending and torsional forces into the surrounding material structure and minimizes critical stress peaks, such as those that can occur with tangential or laterally applied clamping.Furthermore, this results in a structurally clean separation between the active spring area and the passive, force-absorbing section of the base body, which is advantageous for both the organization of the installation space and for reproducibility in the manufacturing process.

[0013] Furthermore, the spring arm can be designed to be aligned parallel to the base body wall in its relaxed state. This results in an optimized rest position for the spring arm, where it is guided along the wall structure without preload or deflection. The parallel alignment not only improves the guidance of the spring arm within the recess but also contributes to a particularly compact design, as the spring arm does not occupy any additional volume outside the wall contour when unloaded. Moreover, this design simplifies manufacturing, as the spring arm geometry can be more easily integrated into rotationally symmetrical or linearly guided tool shapes. The parallel alignment also supports a defined and repeatable deflection characteristic under load, since the deflection direction is exactly perpendicular to the original installation position.

[0014] In a further advantageous embodiment, a stiffening rib, preferably oriented radially to the axis of rotation, is arranged within the base body wall. This allows the mechanical stiffness of the wall structure to be specifically increased, particularly in the radial direction, where bending and shear forces can occur due to the action of the spring arm during deflection. The stiffening rib acts as a structural support, assisting in the absorption and dissipation of these forces while simultaneously preventing deformation or unwanted compliance of the wall structure. This stabilizes the position of the spring arm within the recess, and the spring's restoring characteristic remains constant even under prolonged load or temperature fluctuations. The stiffening rib can also serve as a guide element for the spring arm or as a contact surface for limiting movement, thus expanding the component's functional scope.

[0015] In another advantageous embodiment, the base body wall is concave in the area of ​​the retaining bearing, viewed from the axis of rotation. This results in a positive-locking embedding of the retaining bearing in a correspondingly shaped receptacle, allowing the component to self-center during assembly and be securely positioned against relative rotation. The concave shape promotes the uniform distribution of circumferential forces, as it favors a large contact area and reduces point load concentrations. Particularly when absorbing circumferential torsional moments, the concave geometry leads to improved force transmission into the adjacent wall areas, thus increasing the torsional stiffness of the overall structure. Additionally, the concave shape can be used as a defined contact surface for additional locking elements, such as locking lugs or fitting structures.

[0016] In a further embodiment, the base body wall, viewed from the axis of rotation, features a bulge opposite the retaining bearing, directed into an interior enclosed by the base body wall. This creates a locally projecting structure within the interior, serving for targeted reinforcement, functional enhancement, or geometric adaptation. The bulge can be used as a contact or limiting surface for the spring arm, for example, to define movement limitations or for positioning in the unloaded state. Simultaneously, the bulge acts structurally as an additional stiffener of the wall structure by increasing the bending stiffness in the axial direction and supporting the dimensional stability of the interior. The bulge can also accommodate further functional elements, such as damping zones, guide lugs, or integrated locking tabs.Furthermore, the targeted arrangement on the side opposite the holding bearing achieves a more uniform material distribution within the base body wall, which reduces stress differences under torsional load.

[0017] In a further embodiment, the base body has a circumferentially oriented stop wall on its rear and / or front side when viewed around the axis of rotation. This creates a defined mechanical limit that restricts the movement of either the spring arm or the entire housing / base body relative to the sensor carrier. The stop wall acts as a positive-locking retaining element during circumferential deflection and prevents the spring from being stressed beyond its intended working range. This contributes to the component's longevity and reduces the risk of material fatigue due to excessive deformation. Depending on its arrangement on the front and / or rear, the stop wall can function as a one-sided or two-sided end stop and can optionally serve to adjust or lock the component in its installed state.Furthermore, it supports space-defining integration into surrounding housing or bearing structures.

[0018] According to a further aspect of the invention, a rotary angle sensor for detecting a rotation angle between a rotor and a stator comprises the rotor and the stator with a housing and a circuit board for evaluating a sensor field influenced by the rotor, as well as one of the specified devices for securing a rotational position of the housing relative to a sensor carrier about a rotational axis. Integrating one of the specified position-locking devices into the rotary angle sensor offers several advantages for the sensor function itself. In particular, the directionally defined, structurally stable connection of the housing achieves a reproducible fixation of the stator position relative to the rotor, thereby improving the measurement accuracy, repeatability, and thermal stability of the sensor.Furthermore, the long-term stability of the calibration is increased, and the assembly process is simplified, which has a positive effect on the overall reliability of the sensor system.

[0019] The properties, features, and advantages of this invention described above, as well as the manner in which they are achieved, will become clearer in connection with the following description of the exemplary embodiments, which are explained in more detail in conjunction with the drawings. The drawings show: Fig. 1. A structural view of a vehicle with a sensor for detecting a rotation angle and torque, Fig. 2 a structural view of the sensor for detecting a rotation angle and a torque from Fig. 1, Fig. 3a A structural view of a conventional device for securing the position of the sensor of the Fig. 1 in the vehicle, Fig. 3b a structural view of a device according to the invention for securing the position of the sensor of the Fig. 1 in the vehicle, Fig. 4 a perspective view of the device according to the invention in a first embodiment, and Fig. 5 a perspective view of the device according to the invention in a second embodiment.

[0020] The figures use identical technical elements with the same reference symbols and describe them only once. The figures are purely schematic and, above all, do not represent the actual geometric relationships.

[0021] It will be on Fig. 1 Reference is made to Figure 1, which schematically shows a perspective view of a vehicle 1 with a steering system 2.

[0022] In the present embodiment, the vehicle 1 comprises a chassis 5 supported by two front wheels 3 and two rear wheels 4. The front wheels 3 can be turned via the steering system 2 so that the vehicle 1 can be driven around a curve. The steering system 2 comprises a steering wheel 6, which is mounted on a first steering shaft 7, which in turn is rotatably arranged about a rotational axis 8. The first steering shaft 7 is guided into a sensor 9 for detecting a position, here in the form of an angular position, and is connected there, in an unspecified manner, to a torsion element 10. The torsion element has a freely selectable spring constant, which should preferably be constant and linear, and thus converts an applied torque into a measurable torque angle.On the side opposite the first steering shaft 7, a second steering shaft 11 is connected to this torsion element 10 on the axis of rotation 8, which in turn terminates in a steering gear 12. When the steering wheel 6 is turned with a torque in the form of a steering torque 13, the steering torque 13 is transmitted accordingly via the steering shafts 7, 11 to the steering gear 12, which in response turns the front wheels 3 for cornering with a wheel angle 14.

[0023] The steering process is assisted by an auxiliary motor 15, which also rotates the second steering shaft 11. For this purpose, the steering torque 13 is derived from a difference in the angle of rotation 16 between the first steering shaft 7 and the second steering shaft 11, which is detected by the inductive sensor 9. The auxiliary motor 15 then rotates the second steering shaft 11, among other things, depending on the detected steering torque 13.

[0024] To detect the aforementioned difference in rotational angle 16 and thus the steering torque 13, the sensor 9 comprises a fine track 17 connected to the first steering shaft 7 and a coarse track 18 connected to the second steering shaft 11, which will be discussed in more detail later. The sensor 9 also includes a measuring circuit 19 permanently connected to the vehicle 1, which detects the angular position of the fine track 17 and the angular position of the coarse track 18 and determines the difference in rotational angle 16 from this. This will also be discussed in more detail later. Based on the difference in rotational angle 16, a control unit 20 can now control the auxiliary motor 15 with a suitable control signal 21.

[0025] In addition to the difference in rotation angle 16, the measuring circuit 19 of the sensor 9 also determines a rotation angle 22 of the total steering shaft 7, 11, in order to use it, for example, in a vehicle dynamics system.

[0026] The structure of sensor 9, which forms the basis for the explanation of the present embodiment, is described below with reference to the Fig. 2 explained in more detail.

[0027] While the coarse track 18 is fixedly attached to the second steering shaft 11, the fine track 17 is held on the first steering shaft 7 via a support sleeve 23. A drive wheel 24 is also fixedly attached to this support sleeve 23, which drives an output wheel 25 for a multi-angle detection device 26 in a manner to be described later.

[0028] The fine track 17 is designed in the present embodiment as a fan wheel with a fine track number of fine track blades 27 made of metal. The individual fine track blades 27 are distributed equidistantly around the first steering shaft 7 in the circumferential direction and are held on a fine track support 28. For the following explanations, it will be assumed that there are twelve fine track blades 27, although in Fig. 2 significantly more fine-track wings 27 are shown.

[0029] Similarly, the coarse track 18 in the present embodiment is also designed as a fan wheel with a coarse track number of coarse track blades 29 made of metal. The individual coarse track blades 29 are also equidistantly distributed around the first steering shaft 7 in the circumferential direction, analogous to the fine track 17, and are held on a coarse track support 30. For the following explanations, a coarse track number of eight coarse track blades 29 will be assumed. These coarse track blades 29 are, in the perspective of the Fig. 2 not all coarse-gauge wings are visible.

[0030] The measuring circuit 19 can determine the rotation angle 22 using the coarse-track wing 29 and the fine-track wing 27. For this purpose, the measuring circuit 19 can be designed as described in EP 3 865 824 A1.

[0031] The measuring circuit 19 has a fine-track side 31 facing the fine-track arms 27 and a coarse-track side 32 facing the coarse-track arms 29. On each side of the measuring circuit 19, a transmitting coil (not shown) generating a preferably high-frequency magnetic field and at least one receiving coil (not shown) are arranged, in which a voltage is induced by the magnetic field. On the fine-track side 31, a fine-track signal is thus excited in the corresponding receiving coil, while on the coarse-track side 32, a coarse-track signal is excited in the corresponding receiving coil.

[0032] In this configuration of the measuring circuit 19, the vanes 27, 29 disrupt the magnetic field generated by the respective transmitting coil, causing the fine-track and coarse-track signals to change depending on the rotation angle of the respective track 17, 19. This basic configuration can be extended, for example, to make the measuring system more robust against measurement errors. Such an extension is discussed in EP 3 865 824 A1, which has already been cited. However, such extensions are not essential for understanding the present design.

[0033] As a result, understanding the embodiment depends solely on the fact that the wings 27, 29 of the tracks 17, 18 provide track signals that change periodically with the angular position of the respective track 17, 18.

[0034] In addition to the track signals, the multi-angle detection device 26 also outputs a magnetic angle signal. This magnetic angle signal is generated in a magnetic sensor element 37 based on a radially magnetized magnet 36, which is arranged on the side of the output wheel 25 facing the circuit board 19 and is rotated by the output wheel 25 above the magnetic sensor element 37.

[0035] The rotation angle 22 of the total steering shaft 7, 11 is then calculated on the circuit board 19 from the track signals and the magnetic angle signal and output via an output interface 38.

[0036] In the sensor 9 described above, the measuring circuit 19 is fixedly connected to the vehicle 1 and thus fixed relative to the axis of rotation 8. In order for the angular positions of the fine track 17 and the coarse track 18 to be detected correctly, it is necessary that the measuring circuit 19 – and thus the housing supporting it – is secured in its rotational position precisely against rotation relative to the axis of rotation 8.

[0037] While this must be achieved in the circumferential direction – i.e., around the axis of rotation 8 – by means of a suitable anti-rotation device, there is also the challenge of securing the housing radially relative to the axis of rotation 8. This is because manufacturing tolerances, thermal expansion, or installation forces can lead to radial displacement or tilting of the housing, which in turn results in a displacement of the transmitting and receiving coils of the measuring circuit 19 relative to the vanes 27, 29 or relative to the magnet 36.

[0038] Such radial positional deviations can, particularly when using high-frequency magnetic fields, lead to a change in the coupling characteristics between the coil and the track element, which in turn can affect the amplitude and phase of the received track signals. This also applies analogously to the magnetic angle signal of the magnetic sensor element 37. Even small positional deviations in the submillimeter range can lead to systematic measurement errors or increased temperature sensitivity of the angle signals.

[0039] Against this background, precise and permanently stable radial positioning of the measuring circuit 19 relative to a sensor carrier fixed to the chassis 5 of the vehicle 1 is particularly important. A radial positional deviation of the measuring circuit 19, for example due to manufacturing tolerances, temperature influences, or mechanical stress during installation, can lead to a displacement of the transmitting and receiving coils relative to the fine-track wings 27, the coarse-track wings 29, or the magnet 36. This displacement affects the coupling between the coils and the wing structures or the magnetic field, which can alter the amplitude, phase, or linearity of the detected track signals and the magnetic angle signal. To prevent this, the measuring circuit 19 must be held in a positionally accurate and positively locked position relative to the sensor carrier and thus to the chassis 5.

[0040] For this purpose, a device 40 is used to secure the position of the sensor 9 in the vehicle 1 relative to the sensor carrier and thus to the chassis 5, which is initially determined by means of the Fig. 3a and Fig. 3b will be explained in principle. This will be illustrated Fig. 3a the principle of a conventional device 39, as known from DE 10 2022 103 722 A1 and Fig. 3b a device 40 according to the present invention. To simplify the following descriptions, the devices 39, 40 are to be considered below in a cylindrical coordinate system with an axial direction 42 running parallel to the axis of rotation 8, a circumferential direction 44 running around the axis of rotation 8, and a radial direction 46 running transversely to the axial direction 42 and transversely to the circumferential direction 44. It is important for understanding the function that the sensor 9 does not necessarily have to be located behind the device 39, 40 in the circumferential direction 44. In operation, the sensor 9 is generally located behind the device 39, 40 when viewed in the radial direction 46, which will be explained in later sections. Fig. 4 and Fig. 5 is shown specifically.

[0041] Both the conventional device 39 and the device 40 according to the invention have a base body 48 and a spring 50, which is held on the base body 48 by a retaining bearing 52. The spring 50 is intended to exert a restoring force directed against the circumferential direction 44 on the sensor carrier and thus on the chassis 5 in order to firmly position the sensor 9 in the circumferential direction 44 as described above.

[0042] As in DE 10 2022 103 722 A1, the possibility of applying the restoring force via springs independent of the base body 48 is costly, complicated to manufacture, and maintenance-intensive. Therefore, a one-piece manufacturing of the spring 50 with the base body 48 is proposed. The spring 50 of this known device 39 has a spring arm 54 which is connected to the retaining bearing 52 and thus to the base body 48 via a spring foot 56.

[0043] The conventional device 39 has, viewed in the circumferential direction 44, a first spring arm side 58, which is directed towards the sensor carrier and thus towards the chassis 5, and a second spring arm side 60, which is directed towards the base body 48. DE 10 2022 103 722 A1 teaches that the second spring arm side must be directed towards the base body 48, which means that, viewed in the circumferential direction 44, the entire spring foot 56 and the retaining bearing 52 are located in front of the base body 48, and the spring arm 54 must run at an acute angle to the base body 48, since otherwise no restoring force can be applied.

[0044] However, this acute angle of the spring arm 54 to the base body 48 with respect to the axial direction 42 and thus to the axis of rotation 8 results in several disadvantages. First, the acute angle between the path of the spring arm 54 and the axial direction 42 leads to an unfavorable force flow in the area of ​​the spring base 56. The restoring force to be applied by the spring 50 must act essentially against the circumferential direction 44, while the spring arm 54 enters the base body 48 at a steep angle. This creates a torsional and bending stress, especially at the point of the acute angle in the area of ​​the spring base 56, which is significantly greater than the mechanical stress on the opposite underside of the conventional device 39 as viewed in the axial direction 42.This leads to an unfavorable force redirection, which causes a local increase in stress in the material at the point of the tip angle and noticeably increases the risk of material fatigue or cracking in the transition area between spring foot 56 and retaining bearing 52.

[0045] Furthermore, the acute-angled arrangement necessitates a long, obliquely extending spring arm 54 to generate the desired restoring force against the circumferential direction 44. This negatively impacts the absolutely necessary installation space, as the spring 50 must extend noticeably away from the base body 48 in both the circumferential direction 44 and the axial direction 42 to position the spring head, opposite the spring foot 56, sufficiently far from the base body 48. The less installation space available, the more difficult it becomes to integrate the sensor 9 into correspondingly compact modules or housing designs.

[0046] Finally, the geometric acute angle results in a limited range of motion for the spring arm in the direction of its main deflection. When deflecting towards the sensor carrier, the bending stress can increase rapidly, limiting the effective spring action and increasing the risk of overload under shock or continuous loads.

[0047] The device 40 according to the invention addresses this by arranging the spring base 56 and at least the second side of the spring arm 60 within the base body 48. This arrangement makes it possible to align the spring arm 54 in a substantially perpendicular direction to the circumferential direction 44, so that when the sensor carrier is rotated, the spring arm moves along a line that is orthogonal to the direction of the applied restoring force. This has several technical advantages: Firstly, this results in a force-flow-oriented material stress distribution, since the restoring force of the spring 50 is now transmitted transversely to the main expansion direction of the spring arm 54. The bending stress is distributed more evenly across the retaining bearing 52, thereby reducing stress peaks in the material.

[0048] Secondly, the right-angled geometry allows for a shorter and more compact spring structure, resulting in more linear and defined force transmission. The spring characteristic can be dimensioned more precisely because there are no inclined bending paths that would have a non-linear effect on the restoring force. This improves the reproducibility of the spring behavior, especially under fluctuating temperatures or continuous dynamic loads during driving.

[0049] Furthermore, the right-angled installation position in the base body 48 can be implemented more easily and robustly from a manufacturing perspective, since the shape offers clearly defined wall conditions on which the spring can be guided and supported.

[0050] The following is based on Fig. 4 a specific embodiment of the device 40 according to the invention is described.

[0051] The base body of the device 40 of the Fig. The device 4 is essentially hollow and cylindrical in construction and has a base wall 62 that surrounds the axial direction 42 and separates an interior space 64 from an exterior space 66. As already indicated above, the spring 50 is located at the front of the device 40 when viewed in the circumferential direction 44, while the device 40 is attached to the sensor 9 at its rear when viewed in the radial direction 46. The attachment can be achieved using fasteners, or it can be achieved by a one-piece design with parts of the sensor 9, such as a housing that encloses the components.

[0052] A one-piece design means that the base body 48 – possibly together with the sensor component – ​​is manufactured from a single piece of material using a uniform forming process, in particular injection molding, without the need for subsequent joining processes such as gluing, screwing, or clipping. Such a one-piece design ensures a force-fit and tolerance-free connection between the device 40 and the sensor 9, thereby guaranteeing precise and permanently stable positioning. At the same time, assembly effort is reduced, which is particularly advantageous in automated production lines.

[0053] Another advantage of the one-piece design is that force flows from spring 50 can be transferred directly into the surrounding sensor structure without material or geometric transitions acting as potential weak points. This improves the mechanical robustness of the entire sensor assembly and increases its service life under cyclic loading. Furthermore, the one-piece integration opens up design freedoms, allowing for the direct integration of additional features such as sealing lips, locking tabs, or plug-in contours.

[0054] On the front side as seen in the radial direction 46, the base body wall 62, in the area of ​​a connection point to the sensor 9, has a concave curvature 68 extending into the interior. Similarly, on the outer side as seen in the radial direction 46, the wall has a further curvature 70 extending into the interior 64, so that the two curvatures 68 and 70 are directed towards each other and point towards each other with their respective maxima (not further referenced). The interior 64 of the base body 48 is braced at these maxima by a strut wall 72.

[0055] The concave curves 68, 70 and their connection by the strut wall 72 act as a local stiffening unit, which specifically stabilizes the base body wall in the area of ​​the connection point. The shape creates a double-shell structure with a strut-like connection, whose effect is comparable to a local rib or sandwich construction. Particularly under torsional or bending stress on the base body, the strut wall can transfer the forces occurring over a surface area into the surrounding wall structure, thereby preventing stress concentrations and reducing material fatigue.

[0056] Since the connection point to the sensor 9 is located on the rear side of the device 40 as viewed in the radial direction 56, it acts as a central force transmission point between the sensor 9 and the device 40. The bracing in the area of ​​the curvature maxima supports the mechanical connection and ensures a directed return of the forces introduced there, in particular from the spring arm 54. The curvatures thus assume the function of a force-flow guiding volume, similar to a positive locking element or a shaped load path guide.

[0057] The concave shape on both sides of the base body wall 62 allows the material to be arranged according to the load without requiring massive wall thicknesses. This saves weight and material costs while maintaining high stiffness. The symmetrical shape also promotes uniform component cooling during injection molding and reduces the risk of sink marks or warping.

[0058] The concave curves also serve as mounting or guiding features – for example, for axial positioning in a sensor carrier or as contact surfaces for seals, locking lugs, or guide sleeves. The central strut wall provides a defined contact surface that could also be used for additional functional elements (e.g., clips, centering pins, etc.).

[0059] The base body wall 62 has, on its front side as viewed in the circumferential direction 44, an axial recess 74 extending upwards from its underside as viewed in the axial direction 42. This recess has a recess base 76 located at its upper end as viewed in the axial direction 74, which connects the remaining base body wall 62 in the radial direction 64. The spring 50 rests, or rather hangs, on this recess base 76 opposite to the axial direction 42, so that the recess base 76 serves as the retaining bearing at this point. In its relaxed state, the spring 50, with its spring arm 54, is at the same height as the base body wall 62 as viewed in the circumferential direction 44 and can pivot both into the interior 64 and into the exterior 66.

[0060] If the spring 50 needs to be protected from overextension, a limitation of movement of the spring 50 against the circumferential direction 44 can be enforced by a suitable arrangement of the strut wall 72 or by other stop means.

[0061] For fixing in the axial direction 42, a hook 78 can be formed at the end of the spring 50 opposite the spring foot 56, creating an undercut facing against the axial direction 42, which can engage with a suitable countermeasure on the sensor carrier held stationary to the chassis 5. For coarse positioning of the device 40, positioning walls 80 extending in and against the circumferential sight 44 can be formed on the base body 48.

[0062] It will now be discussed with reference to Fig. 5. A further development of the device 40, described in which the spring arm 54 of the spring 50 has a spring foot 56 at each of its ends as viewed in the axial direction 42, so that the spring 50 is fixed to the base body 48 at two ends. The elasticity is achieved by breaking open the recess base 76 described above, so that two recesses 74 are formed which extend in opposite directions into the base body wall 62 as viewed in the axial direction 42. And finally, two recess bases 76 are formed.

[0063] In this way, the spring arm 54 is no longer designed as a self-supporting cantilever, but as a bending beam structure clamped at both ends, which leads to a more symmetrical stress distribution in the material and thus to higher fatigue strength. The transition areas of the spring feet 56 into the recess bases 76 are in Fig.5 geometrically protected and embedded in a force flow-optimized manner by the course of the base body wall 62, which further reduces the risk of local stress peaks and fatigue fractures.

[0064] Secondly, the double bearing arrangement allows for a more defined movement kinematics of the spring arm 54, as it is loaded and unloaded symmetrically when deflected around the circumferential direction 44. This improves the restoring behavior and increases the reproducibility of the spring characteristic curve, even under thermal or dynamic loads. Furthermore, the integration of both bearing points into the wall structure of the base body 48 enables a very compact design, since the spring arm 54 is guided entirely within the wall thickness of the base body wall 62.

[0065] In addition, the double-sided anchoring creates the possibility of integrating further functional elements – such as damping elements, stops, or positioning aids – between the two bearing points. The spring 50 thus becomes a structural component that not only transmits restoring forces to the sensor carrier but also actively contributes to the mechanical stability of the device 40. Reference symbol list 1 vehicle 2 Steering system 3 front wheels 4 rear wheels 5 chassis 6 Steering wheel 7 First steering shaft 8 Rotation axis 9 Sensor 10 Torsion element 11 Second steering shaft 12 Steering gear 13 Steering torque 14 Wheel angle 15 Auxiliary engine 16 Rotation angle difference 17 Fine gauge 18 coarse gauge 19 Measuring circuit 20 Control unit 21 Control signal 22 Rotation angle (total steering shaft) 23 Carrying sleeve 24 drive wheel 25 Output gear 26 Multi-angle detection device 27 fine-track wings 28 fine-track carriers 29 coarse-gauge wings 30 coarse track beams 31 Fine-track page 32 Coarse gauge page 33 Fine-track signal 34 coarse-gauge signal 36 Magnet 37 Magnetic sensor element 38 Output interface 39 Conventional device 40 Device according to the invention 42 Axial direction 44 Circumferential direction 46 Radial direction 48 basic shapes 50 springs 52 retaining bearings 54 Spring arm 56 Spring foot 58 First side of spring arm 60 Second side of spring arm 62 Base body wall 64 Interior 66 Outdoor area 68 Inner bulge 70 Outer curvature 72 strut wall 74 Axial recess 76 recess floor 78 hooks 80 Positioning wall

Claims

Device (40) for securing a rotation angle sensor (9) determining the rotation angle between a rotor and a stator relative to a sensor carrier about an axis of rotation (8), comprising: - a base body (48), - a torsionally rigid retaining bearing (52) viewed in the circumferential direction (44) about the axis of rotation (8) for absorbing a torsional force from the rotation angle sensor (9), and - a spring (50) held on the retaining bearing (52), which is configured to apply a restoring force to the sensor carrier, with at least one spring foot (56) and a spring arm (54) extending at least partially axially (42) with respect to the axis of rotation (8), which, viewed in the circumferential direction (44) about the axis of rotation (8), comprises a forward-facing spring arm side (58) and a rearward-facing spring arm side (60) opposite the forward-facing spring arm side, characterized in that - the spring foot (56) and at least one of the spring arm sides (58,60) are arranged within the base body (48). Device (40) according to claim 1, wherein the base body (48) comprises a circumferential base body wall (62) in relation to the axis of rotation (8) in an axial direction (42), within which the spring arm (54) is arranged. Device (40) according to claim 2, wherein the base body wall (62) has a recess (74) seen in the axial direction (42) of the axis of rotation (8), within which the spring arm (54) is arranged. Device (40) according to claim 3, wherein the spring foot (56) is arranged on a bottom side (76) of the recess (74) as seen in the axial direction (42) of the axis of rotation (8). Device (40) according to one of claims 2 to 4, wherein the spring arm (54) is aligned parallel to the base body wall (62) in a relaxed state. Device (40) according to one of claims 2 to 5, wherein a stiffening rib is arranged within the base body wall (62), preferably oriented radially (46) to the axis of rotation (8). Device (40) according to one of claims 2 to 6, wherein the base body wall (62) is concave in the area of ​​the retaining bearing (52), as seen from the axis of rotation (8). Device (40) according to one of claims 2 to 7, wherein the base body wall (62), viewed from the axis of rotation (8) opposite the retaining bearing (52), has a bulge (70) directed into an interior space (64) enclosed by the base body wall (62). Device (40) according to one of the preceding claims, wherein the base body (48) has a stop wall (80) oriented in the circumferential direction (44) about the axis of rotation (8) on the rear and / or on the front. Rotation angle sensor (9) for detecting a rotation angle between a rotor and a stator, comprising the rotor and the stator with a housing and a circuit board (19) for evaluating a sensor field influenced by the rotor, and a device (40) according to one of the preceding claims, for securing a rotational position of the housing relative to a sensor carrier about a rotational axis (8).

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