RETRACTABLE STEERING WHEEL ARRANGEMENT FOR A STEER-BY-WIRE STEERING SYSTEM

Abstract

A steering system for a vehicle has a steering system support column and a steering wheel arrangement having a central axis. The steering wheel arrangement includes a steering wheel and a steering wheel hub, rotatable together about the central axis; a torque feedback device; and a steering wheel center part including an airbag module arranged inside the steering wheel center part and being provided with a plurality of steering wheel controls. The steering wheel center part is fixedly connected with the steering system support column so as to be non-rotatable about the central axis. The steering wheel arrangement is column stalk control free, and the steering system is moveable so that the steering wheel arrangement is reversibly retractable and extendable.

Claims

1. A steering system for a vehicle, in particular for an autonomous vehicle, the steering system comprising a steering system support column and a steering wheel arrangement having a central axis; wherein the steering wheel arrangement comprises a steering wheel having a steering wheel rim and at least one spoke, a steering wheel hub fixedly connected with the steering wheel and extending from the steering wheel towards a dashboard of the vehicle, the steering wheel hub and the steering wheel being rotatable about the central axis, a torque feedback device including an electric machine having a rotor and a stator, the rotor being attached to the steering wheel hub and being rotatable about the central axis, and the stator being fixedly attached to the steering system support column which is non-rotatable about the central axis, and a steering wheel center part including an airbag module arranged inside the steering wheel center part and being provided with a plurality of steering wheel controls, the steering wheel center part being fixedly connected with the steering system support column or the stator so as to be non-rotatable about the central axis; wherein the steering wheel arrangement is column stalk control free, and wherein the steering system is moveable so that the steering wheel arrangement is reversibly retractable in a direction towards the dashboard of the vehicle and extendable in a direction away from the dashboard of the vehicle; wherein a rear surface of the steering wheel that faces the dashboard of the vehicle is formed at least partially complementary to a dashboard front surface facing the rear surface of the steering wheel; and wherein the steering wheel rim has a non-planar shape, wherein at least one portion of the steering wheel rim is curved towards the dashboard of the vehicle.

2. The steering system according to claim 1, wherein the steering wheel controls include comprise at least one of turn signal controls, light controls, at least one horn control, driver aid controls, infotainment controls, wiper controls, or cruise controls.

3. The steering system according to claim 1, wherein the steering wheel controls can comprise at least one of single click push buttons, multiple click push buttons, touch sensitive buttons, analogous rotary buttons, digital rotary buttons, monostable levers, or multistable levers.

4. The steering system according to claim 1, wherein at least one additional control is arranged on the steering wheel, preferably on the at least one spoke.

5. The steering system according to claim 1, wherein the steering system is axially moveable along the central axis.

6. The steering system according to claim 1, wherein the steering wheel arrangement has a retraction travel between 50 mm and 150 mm.

7. The steering system according to claim 1, wherein the airbag module is located offset from the central axis of the steering wheel arrangement.

8. The steering system according to claim 1, wherein the airbag module is arranged on the steering wheel center part in such a way that an airbag module central axis is non-parallel to the central axis of the steering wheel arrangement.

9. (canceled)

10. The steering system according to claim 1, wherein in a completely retracted state of the steering wheel arrangement, at least 40% of the rear surface of the steering wheel abuts the dashboard front surface, preferably at least 50%, more preferably at least 60%, still more preferably at least 70%.

11. The steering system according to claim 1, wherein the rotor is an outer rotor and the stator is an inner stator.

12. The steering system according to claim 1, wherein the steering system support column forms an inner member of a tubular telescope arrangement, wherein the inner member is translationally movable, non-rotatable, and non-pivotable relative to an outer member of the tubular telescope arrangement.

13. The steering system according to claim 12, wherein the outer member of the tubular telescope arrangement is a vehicle support column via which the steering system support column is attached to a vehicle body, and wherein the vehicle support column is at least one of adjustable relative to the vehicle body by being pivotable or radially displaceable relative to the vehicle body.

14. (canceled)

15. The steering system according to claim 1, wherein at least one display unit is provided in an area of the steering wheel rim.

16. The steering system according to claim 1, wherein the vehicle is an autonomous vehicle.

17. The steering system according to claim 4, wherein at least one additional control is arranged on the at least one spoke.

18. The steering system according to claim 6, wherein the retraction travel is between 60 mm and 120 mm.

19. The steering system according to claim 18, wherein the retraction travel is between 80 mm and 100 mm.

20. The steering system according to claim 10, wherein in the completely retracted state of the steering wheel arrangement, at least 50% of the rear surface of the steering wheel abuts the dashboard front surface.

21. The steering system according to claim 20, wherein in the completely retracted state of the steering wheel arrangement, at least 60% of the rear surface of the steering wheel abuts the dashboard front surface.

22. The steering system according to claim 21, wherein in the completely retracted state of the steering wheel arrangement, at least 70% of the rear surface of the steering wheel abuts the dashboard front surface.

Description

[0099] In the accompanying drawings:

[0100] FIGS. 1A to 1C show schematic front, side and top views of a steering system according to an embodiment of the invention.

[0101] FIGS. 2A and 2B show the front view of FIG. 1A in more detail and with different rotational orientations.

[0102] FIGS. 3A to 3D show schematic side and top views of the steering system of FIGS. 1A to 1C together with a dashboard design.

[0103] FIGS. 4A and 4B show schematic side and top views of the steering system of FIGS. 1A to 1C together with another dashboard design.

[0104] FIG. 5 shows a schematic perspective view of the steering system according to another embodiment of the invention.

[0105] FIGS. 6A and 6B show schematic side and top views of the steering system of FIG. 5 together with a dashboard design.

[0106] FIGS. 7A to 7C show schematic views of the steering system according to another embodiment of the invention.

[0107] FIG. 8 shows a schematic perspective view of the steering system according to another embodiment of the invention.

[0108] FIG. 9 shows a schematic perspective view of the steering system according to another embodiment of the invention.

[0109] FIG. 10 shows a schematic perspective view of the steering system according to another embodiment of the invention

[0110] FIGS. 11A to 11F show schematic views of a steering system according to another embodiment of the invention

[0111] FIGS. 12A to 12C show schematic views of the steering wheel rotation limiting device and the steering wheel hub for illustrating the functional principle of the steering wheel rotation limiting device.

DETAILED DESCRIPTION

[0112] Various examples of embodiments of the present invention will be explained in more detail by virtue of the following embodiments illustrated in the figures and/or described below.

[0113] FIGS. 1A to 1C show schematic views of a steering system 10 for an autonomous road vehicle according to an embodiment of the invention. As can be seen in FIGS. 1A to 1C, the steering system 10 is a steery-by-wire steering system that has no direct mechanical connection for transferring a driver's steering commands from a steering wheel 12 of the steering system 10 to the wheels (not shown) of the vehicle. Instead, the mechanical connections are replaced by an electro-mechanical arrangement.

[0114] The steering system 10 comprises a steering wheel arrangement 11 with the steering wheel 12 and steering wheel hub 14 mechanically connected with the steering wheel 12. The steering wheel hub 14 and the steering wheel 12 are non-rotatable relative to each other, but can be rotated together about a central axis A of the steering wheel arrangement 11. As can be seen, steering wheel 12 comprises a ring-shaped rim 13 and, in the shown embodiment, three spokes 15 that connect the steering wheel rim 13 with the steering wheel hub 14.

[0115] The steering wheel arrangement 11 further includes a torque feedback device for generating torque feedback to the driver. The torque feedback device is housed inside the steering wheel hub 14 and is thus not shown in FIG. 1A to 1C (but shown and denoted with reference sign 44 in FIG. 11A).

[0116] The steering wheel arrangement 11 comprises a steering wheel center part 100 (shown in more detail in and described in connection with FIGS. 2A and 2B). The steering wheel center part 100 is rotationally stationary and is non-rotatably fixed to an end portion of the steering support column 24. The steering wheel center part 100 includes an airbag module integrated and housed therein, wherein the airbag module is configured to deploy the airbag, in case of a crash, in a direction towards the driver.

[0117] The steering system 10 further comprises a steering system support column 24 that is configured to support the steering wheel arrangement 11. The steering system support column 24 can connect the steering wheel arrangement 11 with the chassis of the vehicle. In the shown embodiment, the steering system support column 24 is a tubular member. The steering system support column 24 forms an inner member of a tubular telescope arrangement 80 and is translationally movable relative to a vehicle support column 82 which forms an outer member of the tubular telescope arrangement 80. Consequently, the steering system support column 24 and the steering wheel arrangement 11 supported thereon is translationally displaceable with respect to the central axis A independent of the vehicle support column 82, in order to enable retractability and extendability of the steering wheel arrangement 11. The vehicle support column 82 connects the steering system support column 24 to the vehicle body (not shown) i.a. by adjustment elements 84 (brackets, axial adjustment elements and vertical adjustment elements). Thus, the steering system support column 24 and all components supported thereon are radially displaceable/pivotable relative to the vehicle body dependent on the vehicle support column 82, i.e. the adjustability/displaceability of the vehicle support column 82.

[0118] As can be seen in FIGS. 1B and 1C, the steering wheel arrangement 11 is completely column stalk control free. In other words, the steering wheel arrangement 11 has no column stalk switches or levers arranged thereon. More precisely, the steering wheel hub 14 is completely column stalk control free. Thus, the steering system 10 has no column stalk controls that could block or limit retractability of the steering wheel arrangement 11. In the present embodiment, conventional column stalk controls are replaced by steering wheel controls (see FIGS. 2A and 2B) arranged on the steering wheel center part 100, more precisely on a surface of a steering wheel center pad 102 facing the driver. In the steering system, no controls are arranged between a rear surface of the steering wheel 12 and a front surface of the dashboard (this relates to controls of the steering wheel, however, controls can be provided on the front surface of the dashboard or other vehicle cabin components).

[0119] FIGS. 2A and 2B show the front view of the steering wheel arrangement 11 in more detail and with different rotational orientations. More precisely, the steering wheel 12 has different rotational orientations in FIGS. 2A and 2B. In FIG. 2A the steering wheel 12 is in a basic position in which the steering wheel 12 has not been rotated. This basic position constitutes a position in which the wheels of the vehicle are straight, i.e. have not been turned. FIG. 2B shows the steering wheel 12 in a certain rotated position in which the steering wheel 12 has been rotated about the central axis A in order to turn the wheels of the vehicle. Arrow R shows the rotation direction of the steering wheel 12.

[0120] As can be seen in FIG. 2B, the center part 100 of the steering wheel arrangement 11 is rotationally stationary, i.e. is non-rotatable about the central axis A. Even if the steering wheel 12 is rotated, the center part 100 stays in its basic, non-rotated orientation. Therefore, regardless of a current driving situation and a current rotational orientation of the steering wheel 12, the controls arranged on the center part 100 are readily available of to the driver. This applies even for a transition phase from autonomous driving to manual driving when the autonomous vehicle hands the control of the vehicle back to the driver, which increases safety of autonomous vehicles.

[0121] The center part 100, more precisely the center pad 102, is provided with a plurality of steering wheel controls 104A to 110B. The steering wheel controls 104A to 110B comprise turn and light signal controls 104A and 104B arranged on left and right side flanges of the center pad 102. The turn and light signal controls 104A and 104B replace conventional turn and light signal column stalk control levers. The center pad 102 is further provided with driver aid and cruise controls 106 and wiper controls 108. Further, a horn control is provided on the center pad 102. In the shown embodiment, two alternative horn control positions 110A and 110B are shown.

[0122] Besides the steering wheel controls 104A to 110B arranged on the center pad 102 of the center part 100, additional controls are provided on spokes 15 of the steering wheel 12. In the present embodiment, further driver aid controls 300 and infotainment controls 302 are provided on the spokes 15.

[0123] Moreover, controls can also be arranged on the steering wheel rim 13. In the shown embodiment, alternative horn control positions 210A and 210B are shown.

[0124] The steering wheel controls 104A to 110B as well as the additional controls 210A, 210B, 300, 302 can have different technical configurations depending on their respective function.

[0125] Individual or all of the controls can be formed as single click push buttons, multiple click push buttons, touch sensitive buttons, analogous rotary buttons, digital rotary buttons, monostable levers and/or multistable levers. The push buttons can be pressure force sensitive push buttons. For digital buttons, such as digital rotary buttons, the position of the button can be reset at key-on. Levers provided on the steering wheel center part can have a pivot axis at any position in space.

[0126] FIGS. 3A to 3D show the steering system 10 in retracted positions (FIGS. 3C and 3D) and in extended positions (FIGS. 3A and 3B). Further, the contour of a dashboard of the vehicle is schematically indicated by line 400. The contour of the dashboard is shown in comparison to a conventional dashboard design contour indicated by dashed line 402. The omission of column stalk levers in the present steering wheel arrangement 11 allows new dashboard design options. For example, as shown in FIGS. 3A to 3D, an extension of the dashboard 400 can be increased in direction towards the driver/in direction towards the steering wheel 12compared to conventional dashboardswhile providing the same maximum steering arrangement travel D (retraction travel/extension travel) as a conventional steering system with column stalk levers. In conventional steering systems with column stalk levers, the maximum steering arrangement travel D can be limited due to an abutment of the column stalk levers with the dashboard. Thus, the dashboard extension towards the driver needs to be reduced in order to allow the shown maximum steering arrangement travel D. With the steering system of the shown embodiment, such a limitation has been removed so that the dashboard extension can be increased. This can allow for an optimized dashboard design, e.g. with regard to knee airbag implementation.

[0127] FIGS. 4A and 4B show the steering system 10 in retracted positions together with an alternative dashboard design. The alternative dashboard design further includes an additional extension part 404 so that in a retracted state of the steering wheel arrangement 11, the dashboard and the steering wheel 12 at least partially abut. Preferably, the dashboard and the steering wheel 12 can be formed at least partially complementary so as to allow optimal abutment.

[0128] FIG. 5 shows a schematic perspective view of the steering system 410 according to another embodiment of the invention. The embodiment shown in FIG. 5 substantially corresponds to the embodiment shown in FIGS. 1A to 1C. Yet, unlike the embodiment of FIGS. 1A to 1C, the embodiment of FIG. 5 comprises a steering wheel rim 413 having a non-planar structure relating to a planar reference plane RP. The steering wheel rim 413 is formed as a substantially circular, ring shaped, closed structure forming a grip portion to the vehicle driver. The non-planar steering wheel rim 413 comprises an upper portion 415 that is inclined in a direction towards the vehicle dashboard 400 relative to a middle portion 416 of the steering wheel rim 413. The steering wheel rim 413 comprises a bottom portion 417 that is inclined in a direction towards the vehicle dashboard 400 relative to the middle portion 416 of the steering wheel rim 413.

[0129] The steering wheel rim 413 of FIG. 5 can have a total angle of rotation of 550?. The total angle of rotation can be mechanically limited by a rotation limiting device 52 as shown in FIGS. 12A to 12C.

[0130] FIGS. 6A and 6B show the steering system 410 of FIG. 5 in retracted positions together with a dashboard design. The dashboard design includes an additional extension part 405 so that in a retracted state of the steering wheel arrangement 11, the dashboard and the steering wheel 12 at least partially abut. Preferably, the dashboard and the steering wheel 12 can be formed at least partially complementary so as to allow optimal abutment. As can be seen in FIGS. 6A and 6B, the non-planar steering wheel rim 413 at least partially wraps around a dashboard curvature, which leads to interior space gain (indicated by arrows SG).

[0131] The steering system 410 is configured completely column stalk control free.

[0132] FIGS. 7A to 7C show a steering system 510 according to another embodiment of the invention. Steering system 510 of FIGS. 7A to 7C substantially corresponds to steering system 410 of FIGS. 5 to 6B. Steering system 510 is provided with a display unit 530 mounted on the steering wheel rim 413. More precisely, the display unit 530 is arranged on the inclined upper portion 415 of the steering wheel rim 413. This increases a focal distance FD relating to the display unit 530, which contributes to optimal perceptibility of the display unit 530.

[0133] A further embodiment of a steering system 610 according to the invention is shown in FIG. 8. In contrast to the embodiment of FIGS. 7A to 7C, the steering system 610 of FIG. 8 is provided with an open top portion 630. Nonetheless, the overall structure of the steering wheel rim 413 is mirror symmetrical in this and all other shown embodiments (this is not necessary but preferable). By providing the steering wheel rim 413 with an open top portion 630, the steering wheel rim 413 in this embodiment consequently comprises two inclined upper portions 415, one on each side of the open top portion 630.

[0134] A further embodiment of a steering system 710 according to the invention is shown in FIG. 9. In contrast to the embodiment of FIGS. 7A to 7C, the steering system 710 of FIG. 9 is provided with an open bottom portion 730. Nonetheless, the overall structure of the steering wheel rim 413 is mirror symmetrical in this and all other shown embodiments (this is not necessary but preferable). By providing the steering wheel rim 413 with an open bottom portion 730, the steering wheel rim 413 in this embodiment consequently comprises two inclined bottom portions 417, one on each side of the open top portion 730.

[0135] Even though, no display unit is shown in the embodiments of FIGS. 8 and 9, a display unit (e.g. as shown in FIG. 7) could be provided on the steering wheel rim 413, in particular on the respective closed inclined upper or bottom portion.

[0136] FIG. 10 shows a further embodiment of a steering system 810 according to the invention. In contrast to the embodiment of FIGS. 7A to 7C, the steering system 810 of FIG. 10 is provided with an open top portion 630 and an open bottom portion 730. Nonetheless, the overall structure of the steering wheel rim 413 is mirror symmetrical in this and all other shown embodiments (this is not necessary but preferable). By providing the steering wheel rim 413 with an open top portion 630 and an open bottom portion 730, the steering wheel rim 413 in this embodiment consequently comprises two inclined upper portions 415, one on each side of the open top portion 630, and two inclined bottom portions 417, one on each side of the open top portion 730.

[0137] FIGS. 11A to 11F show schematic views of a steering system 910 with additional features according to an embodiment of the invention. As can be seen in FIGS. 11A to 11F, the steering system 910 is a steery-by-wire steering system that has no direct mechanical connection for transferring a driver's steering commands from a steering wheel 12 of the steering system 10 to the wheels (not shown) of the vehicle. Instead, the mechanical connections are replaced by an electro-mechanical arrangement.

[0138] In addition to the steering wheel 12 with steering wheel rim 13 and spokes 15, a steering arrangement 11 of the steering system 910 comprises a steering wheel hub 14 mechanically connected with the steering wheel 12. The steering wheel hub 14 and the steering wheel 12 are non-rotatable relative to each other, but can be rotated together about a central axis A of the steering wheel arrangement 11. The steering wheel 12 is removably attached to the steering wheel hub 14 in a non-rotatable manner by fixing elements 16 in form of screws. More precisely, the steering wheel 12 is provided with an internal armature 18 inside the spoke 15, wherein the fixing elements 16 extend through through bores 20 of the internal armature 18 into internally threaded blind holes 22 provided in the steering wheel hub 14.

[0139] The steering wheel hub 14 is rotatably supported on a rigid steering system support column 24 of the steering system 910, more precisely on an aligned section 26 of the steering system support column 24. Besides the aligned section 26, the steering system support column 24 comprises an off-axis section 28. The off-axis section 28 is axially spaced from the aligned section 26 and from the steering wheel hub 14, while the steering wheel hub 14 overlaps and is located coaxial to the aligned section 26. The off-axis section 28 has a first longitudinal axis L1 that is off-set and parallel to the central axis A. The aligned section 26 has a second longitudinal axis L2. The aligned section 26 of the steering system support column 24 is aligned with or coaxial to the steering wheel hub 14 and to the steering wheel 12, i.e. the second longitudinal axis L2 corresponds to the central axis A.

[0140] The off-axis section 28 and the aligned section 26 are fixedly connected by a connection portion 30 extending transversally to both the first longitudinal axis L1 and the second longitudinal axis L2.

[0141] The steering wheel hub 14 is rotatably mounted on the aligned section 26 of the steering system support column 24 by a first bearing arrangement 32 and a second bearing arrangement 34, the second bearing arrangement 34 being axially spaced from the first bearing arrangement 32. For example, the first bearing arrangement 32 and/or the second bearing arrangement 34 can be a ball bearing or a roller bearing.

[0142] The first bearing arrangement 32 is supported on a protruding flange portion 36 of the aligned section 26 of the steering system support column 24, which protrudes radially outward from the outer circumferential surface of the aligned section 26. The protruding flange portion 36 provides a circular ring-shaped first bearing surface for supporting the first bearing arrangement 32. The protruding flange portion 36 is arranged in the vicinity of the connection portion 30, i.e. in a transition region between the aligned section 26 and the connection portion 30. Consequently, the first bearing arrangement 32 is axially located at a first end portion of the aligned section 26 oriented towards the connection portion 30.

[0143] The second bearing arrangement 34 is supported on a circular ring-shaped portion 38 of the aligned section 26 of the steering system support column 24. The circular ring-shaped portion 38 is formed in an area of the aligned section 26 following the steering wheel 12 and extending towards the protruding flange portion 36. The circular ring-shaped portion 38 provides a second bearing surface for the second bearing arrangement 34. Thus, the second bearing arrangement 34 is axially located at a second end portion of the aligned section 26 opposing the first end portion.

[0144] The first bearing arrangement 32 is mounted between the protruding flange portion 36 of the aligned section 26 and the steering wheel hub 14 via a support bushing 40 arranged between the first bearing arrangement 32 and the inner circumferential surface of the steering wheel hub 14.

[0145] The second bearing arrangement 34 is mounted directly between the circular ring-shaped portion 38 of the aligned section 26 and the steering wheel hub 14. To this, the steering wheel hub 14 is provided with an inwardly protruding flange portion 42 that provides a counter bearing surface for the second bearing arrangement 34. At the same time, the inwardly protruding flange portion 42 covers components located inside the steering wheel hub 14. As can be seen in FIG. 11A, the blind holes 22 for receiving the fixing elements 16 extend into or through the inwardly protruding flange portion 42.

[0146] The steering system 910 further comprises a torque feedback device 44 including an electric machine having a rotor 46 and a stator 48 with stator windings 50. The torque feedback device 44 can be operated to produce resistance torque to the rotation of the steering wheel 12 so as to simulate the resistance torque present in conventional steering systems. In other words, the torque produced by the torque feedback device 44 can counteract the rotational force applied to the steering wheel 12 by a driver.

[0147] In the shown embodiment, the electric machine is an outer rotor electric machine comprising an outer rotor 46 and an inner stator 48. The rotor 46 is fixed to an inner circumferential surface of the steering wheel hub 14. Thus, the rotor 46 is rotatable together with the steering wheel hub 14 about the central axis A. The rotor 46 is non-rotatable relative to the steering wheel hub 14. The stator 48 is fixed to the rotatably stationary (i.e. non-rotatable) aligned section 26 of the steering system support column 24. Thus, the steering wheel hub 14 and the rotor 46 can rotate together around the stator 48 and the aligned section 26.

[0148] The electric machine of the torque feedback device 44 is arranged inside the steering wheel hub 14. The torque feedback device 44 is radially enclosed and thus covered by the steering wheel hub 14 (the inner circumferential surface of the steering wheel hub 14) and the aligned section 26 of the steering system support column 24 (the outer circumferential surface of the aligned section 26). The torque feedback device 44 is axially located between the protruding flange portion 36 of the aligned section 26 and the circular ring-shaped portion 38 of the aligned section 26. The torque feedback device 44 is axially enclosed and thus covered by the protruding flange portion 36 of the aligned section 26, the first bearing arrangement 32 and the support bushing 40 on one side and by the inwardly protruding flange portion 42 of the steering wheel hub 14 and the second bearing arrangement 34 on the other side.

[0149] The arrangement, configuration and support of the steering wheel hub 14, the steering wheel 12, the torque feedback device 44 and the steering system support column 24 provides a very compact structure. More precisely, as shown in FIG. 11A, various components are arranged at least partially parallel to each other, with respect to their radial and/or axial arrangement.

[0150] Namely, the fixing elements 16 are arranged at different radial positions, i.e. different radial heights, than the stator windings 50, with respect to the central axis A. Hence, the fixing elements 16 and the blind holes 22 at least partially overlap the stator windings 50 in the axial direction. The stator windings 50 can be arranged closer to the central axis A than the fixing elements 16.

[0151] Further, the second bearing arrangement 34 is arranged at a different radial position, i.e. a different radial height, than the stator windings 50 and at a different radial position, i.e. a different radial height, than the fixing elements 16, with respect to the central axis A. In the shown embodiment, the fixing elements 16 overlap the second bearing arrangement 34 in the axial direction. The second bearing arrangement 34 can be arranged closer to the central axis A than the stator windings 50 and can be arranged closer to the central axis A than the fixing elements 16.

[0152] Further, the first bearing arrangement 32 is arranged at a different radial position, i.e. a different radial height, than the second bearing arrangement 34 and at a different radial position, i.e. a different radial height, than the fixing elements 16, with respect to the central axis A. The first bearing arrangement 32 is arranged at a similar radial position as the start windings 50, with respect to the central axis A. The first bearing arrangement 32 can be arranged closer to the central axis A than the stator fixing elements 16 and can be spaced farther from to the central axis A than the second bearing arrangement 34.

[0153] The fixing elements 16 are arranged at similar radial positions as the outer rotor 46 of the torque feedback device 44, with respect to the central axis A. This limits the radial extension of the steering system 910 in the region of the torque feedback device 44.

[0154] The steering system 910 further comprises a steering wheel rotation limiting device 52 for limiting rotation of the steering wheel hub 14 and the steering wheel 12. The steering wheel rotation limiting device 52 is fixed to the steering system support column 24 and is arranged radially offset to the steering wheel hub 14, more precisely adjacent to the outer circumferential surface of the steering wheel hub 14. The steering wheel rotation limiting device 52 is non-rotatable relative to the steering system support column 24.

[0155] The steering wheel rotation limiting device 52 comprises a base 54 and a sliding element 56 arranged inside a compartment 58 formed in the base 54. The sliding element 56 is axially slidable relative to the base 54 and relative to the steering wheel hub 14. The sliding element 56 can slide between the two opposing end stop surfaces 60, 62 (see FIGS. 12A to 12C) of the steering wheel rotation limiting device 52. The sliding element 56 comprises a projection 64 that engages a spiral groove 66 formed on the outer circumferential surface of the steering wheel hub 14. By the interaction of the projection 64 and the spiral groove 66, rotation of the steering wheel hub 14 causes axial movement of the sliding element 56. Likewise, abutment of the sliding element 56 with one of the two end stop surfaces 60, 62 blocks further movement of the sliding element 56 in a certain direction and thus blocks further rotation of the steering wheel hub 14 in a certain direction of rotation. Hence, the steering wheel rotation limiting device 52 is configured to restrict rotation of the steering wheel hub 14 and of the steering wheel 12 connected therewith.

[0156] The base 54 of the steering wheel rotation limiting device 52 is fixed to the off-axis section 28 of the steering system support column 24 by screws 68 (see FIGS. 11A to 11F). The steering wheel rotation limiting device 52, more precisely the base 54, extends in the axial direction from the off-axis section 28 of the steering system support column 24 to the steering wheel hub 14 so that the compartment 58 is arranged between and enclosed by the base 54 and the outer circumferential surface of the steering wheel hub 14.

[0157] Functions and further details of the steering wheel rotation limiting device 52 will be described in the context of FIGS. 12A to 12C.

[0158] The base 54 of the steering wheel rotation limiting device 52 covers an opening 70 configured in the off-axis section 28 of the steering system support column 24. More precisely, the opening 70 is arranged in another transition region between the off-axis section 28 and the connection portion 30. The opening 70 provides access to electric machine phase connections 72 and to electric steering wheel angle sensor connections 74 for service and maintenance purposes. The electric machine phase connections 72 connect the electric machine of the torque feedback device 44 with a control unit/control electronics 76. The electric steering wheel angle sensor connections 74 connect a steering wheel angle sensor 78 with the control unit/control electronics 76.

[0159] The control unit 76 is arranged inside the hollow tubular off-axis section 28 of the steering system support column 24. More precisely, the control unit 76 is arranged in a portion of the off-axis section 28 close to the connection portion 30 so as to locate the control unit 76 and the electric machine close to each other.

[0160] The steering wheel angle sensor 78 is configured to measure a present steering angle and thus to detect the driver's steering command that is to be transmitted electronically to actuator/s for actuating/steering the wheels in line with this command. The steering wheel angle sensor 78 is arranged adjacent or lateral to the first bearing arrangement 32

[0161] The steering system support column 24 forms an inner member of a tubular telescope arrangement 80. The outer member of the tubular telescope arrangement 80 is embodied by a vehicle support column 82. In particular, the off-axis section 28 is mounted axially slidable inside the outer member/vehicle support column 82 of the tubular telescope arrangement 80. Thus, the steering system support column 24 is translationally displaceable relative to the vehicle support column 82 and relative to a vehicle body, but is non-rotatable and non-pivotable relative to the vehicle support column 82.

[0162] The steering system support column 24 is connected to the vehicle vehicle body (not shown) via the vehicle support column 82 by brackets, axial adjustment elements and vertical adjustment elements 84. Consequently, the steering system support column 24 and all components supported thereon are only translationally displaceable with respect to the first longitudinal axis L1 independent of the vehicle support column 82. Further, the steering system support column 24 and all components supported thereon are radially displaceable/pivotable relative to the vehicle body dependent on the vehicle support column 82, i.e. the adjustability/displaceability of the vehicle support column 82.

[0163] The steering system support column 24 has a hollow tubular shape. The steering system support column 24 is formed as a rigid one-piece component and is preferably made of metal. As can be seen in FIGS. 11A to 11F, which show different perspective views of the steering system 910, at least the off-axis section 28 of the steering system support column 24 has a substantially rectangular cross-sectional area. Such a shape can be particularly advantageous for accommodating and attaching the control unit 76. Similar to the off-axis section 28, the vehicle support column 82 that forms the tubular telescope arrangement 80 together with the off-axis section 28 has a substantially rectangular cross-sectional area.

[0164] The connection portion 30 of the steering system support column 24 forms a tapering transition that tapers from the off-axis section 28 towards the aligned section 26. The aligned section 26 has a smaller diameter than the off-axis section 28. The aligned section 26 has a substantially circular cross-sectional area.

[0165] As can be further seen, the steering wheel 12 is provided with an internal space 86 for accommodating the center part (not shown, but shown and denoted with reference sign 100 in FIGS. 1A to 2B). The center part as well as auxiliary components, such as a wiring harness, can extend into the hollow, tubular aligned section 26. The center part as well as the auxiliary components can thus be arranged in and/or attached to the inside of the aligned section 26 of the steering system support column 24.

[0166] FIGS. 12A to 12C serve to disclose details concerning the function and configuration of the steering wheel rotation limiting device 52. FIG. 12A shows the components of the steering wheel rotation limiting device 52 separately, i.e. in an exploded view. FIG. 12B shows the components of the steering wheel rotation limiting device 52 in an assembled state. FIG. 12C shows the steering wheel rotation limiting device 52 mounted to or in interaction with the steering wheel hub 14.

[0167] As can be seen in FIGS. 12A to 12C, four screws 68 extend through base 54 so as to securely fix the steering wheel rotation limiting device 52 to the steering system support column 24.

[0168] The base 54 has a compartment 58 formed therein. Two axially opposing side surfaces of the compartment 58 constitute the end stop surfaces 60, 62. The compartment 58 is formed partially complementary to the sliding element 56 that can be arranged therein (see FIG. 12B). Thus, the compartment 58, more precisely the bottom and the lateral surfaces of the compartment 58, restricts movability of the sliding element 56 to an axial slidability between the two end stop surfaces 60, 62 (indicated by arrows AS). The two end stop surfaces 60, 62 limit the slidability of the sliding element 56 in the axial directions. When the sliding element 56 abuts one of the two end stop surfaces 60, 62, its further movement in the current direction is blocked and the sliding element 56 can only move in an opposite axial direction, i.e. towards the respective opposing end stop surface 60, 62. A surface oriented towards the steering wheel hub 14, in a mounted state, is curved and substantially complementary to a corresponding part of the outer circumferential surface of the steering wheel hub 14.

[0169] The sliding element 56 engages the spiral groove 66 formed in the outer circumferential surface of the steering wheel hub 14 via the projection 64. Projection 64 is formed as a spiral ridge, adapted to the shape and dimension of the spiral groove 66. The sliding element 56 interacts with the steering wheel hub 14 via the spiral groove 66. When the steering wheel 12 and consequently the steering wheel hub 14 rotate, the sliding element 56 is dragged inside the compartment 58 in an axial direction according to one of arrows AS. The sliding element 56 slides until the rotation of the steering wheel hub 14 stops or until a further movement is blocked by an abutment of the sliding element 56 with one of the two end stop surfaces 60, 62. Blocking of further axial movement of the sliding element 56 consequently blocks further rotation of the steering wheel hub 14 and thus of the steering wheel 12 in a direction of rotation that would cause a further axial movement of the sliding element 56 towards the currently blocking end stop surface 60, 62.

[0170] As indicated in FIG. 12A, the sliding element 56 has an axial width W. The axial width W of the sliding element 56 determines the free space inside the compartment 58 between the sliding element 56 and the end stop surfaces 60, 62. Thus, by adapting or choosing the axial width W of the sliding element 56, the maximum travel distance, i.e. the maximum axial movability, of the sliding element 56 between the two end stop surfaces 60, 62 is adjustable.

[0171] Thus, by merely replacing the sliding element 56 and adapting its axial width W and the dimensions and geometry of the projection 64, the steering wheel rotation limiting device 56 can be used flexibly for different vehicle configurations. In particular, the axial width W can be chosen in accordance with one or more of the following parameters: a length of the spiral groove 66, a pitch of the spiral groove 66, a distance between the two opposing end stop surfaces 60, 62, and a circumferential length of the steering wheel hub 14.

TABLE-US-00001 LIST OF REFERENCE SIGNS 10 steering system 44 torque feedback device 11 steering wheel arrangement 46 rotor 12 steering wheel 48 stator 13 steering wheel rim 50 stator windings 14 steering wheel hub 52 steering wheel rotation limiting device 15 spoke 54 base 16 fixing elements 56 sliding element 18 armature 58 compartment 20 through bores 60 end stop surface 22 blind holes 62 end stop surface 24 steering system support column 64 projection 26 aligned section 66 spiral groove 28 off-axis section 68 screws 30 connection portion 70 opening 32 first bearing arrangement 72 electric machine phase connections 34 second bearing arrangement 74 electric steering wheel angle sensor connections 36 protruding flange portion 76 control unit 38 circular ring-shaped portion 78 steering wheel angle sensor 40 support bushing 80 tubular telescope arrangement 42 inwardly protruding flange portion 82 vehicle support column 84 adjustment elements 530 display unit 86 internal space 610 further steering system 88 end portion 630 open top portion 100 center part 710 further steering system 102 center pad 730 open bottom portion 104A to 110B steering wheel controls 810 further steering system 210A, 210B alternative horn control positions 910 further steering system 300, 302 driver aid controls L1 first longitudinal axis 400 dashboard contour L2 second longitudinal axis 402 prior art dashboard contour W axial width 404 additional extension part A central axis 405 additional extension part AS axial direction 410 further steering system R rotation direction 413 further steering wheel rim RP reference plane 415 inclined upper portion SG space gain 416 middle portion FD focal distance 417 inclined bottom portion 510 further steering system