Patent Description:
In the motor vehicle and truck industry there is a continuous development towards autonomous (self-driving) and semi-autonomous vehicles. This development as well as progresses towards fully electric vehicles and autonomous vehicles further promote developments of drive-by-wire steering systems and increase the need for inventive concepts.

One specific aspect in this context relates to an adjustment of the steering wheel position during autonomous operation of the vehicle, when no steering inputs from the driver are necessary. Namely, there is an interest in temporarily relocating the vehicle for generating more interior space for other activities during the autonomous operation, such as reading, watching videos, and/or working on laptops or tablets. Several future visions known of how to adjust the steering wheel have been proposed, many of which rely on folding away the steering wheel.

However, known solutions for adjusting the position of the steering wheel are often subject to complex structures and require considerable time to transition from a driving configuration to an autonomous configuration and back. Also, known solutions may risk leading to safety issues due to adverse operability.

<CIT> relates to a steer-by-wire road vehicle steering system provided with a telescopic support element for the steering wheel. <CIT> relates to a steering wheel. <CIT> relates to a steering wheel and a trim element comprising such a steering wheel.

It is an object of the present invention to provide a steering system which has improved characteristics and overcomes at least some of the disadvantages of the prior art.

In particular, it is an object of the present invention to provide a steer-by-wire steering system having a simple configuration.

Preferably, it is an object of the present invention to provide a steer-by-wire steering system that promotes quick configuration transitions, simple and intuitive operation, reliability and/or low cost.

These objects are achieved by the subject matter of the independent claims. Preferred embodiments and preferred features are specified in the dependent claims and the following description.

The invention relates to a steering system for a vehicle, in particular for an autonomous or semi-autonomous vehicle. The steering system is preferably a steer-by-wire system.

The steering system comprises a steering system support column and a steering wheel arrangement having a central axis. The steering wheel arrangement being connected with the steering system support column.

The steering wheel arrangement includes a steering wheel having a steering wheel rim and having at least one spoke. The steering wheel rim can be at least partially arc-shaped. The steering wheel rim can comprise at least one circular segment, more precisely at least one ring section or a fully closed ring. Preferably, the steering wheel rim is substantially, i.e. to most parts, arc-shaped. The steering wheel rim can comprise a plurality of circular segments or ring sections. The steering wheel rim provides a grip portion to the vehicle driver.

The steering wheel arrangement further includes a steering wheel hub fixedly connected with the steering wheel. Fixedly connected or attached can mean that the connected or attached components are not movable relative to each other, neither rotatably nor translationally. The steering wheel hub extends from the steering wheel in a direction towards a dashboard of the vehicle. The steering wheel hub and the steering wheel are rotatable together about the central axis of the steering wheel arrangement.

The steering wheel arrangement comprises a torque feedback device including an electric machine having a rotor and a stator. The rotor is attached to the steering wheel hub and is rotatable together with the steering wheel hub (and the steering wheel) about the central axis. The stator is fixedly attached to the steering system support column, preferably to a section of the column that extends along the central axis, wherein the steering system support column is non-rotatable about the central axis. In other words, the steering system support column is rotationally stationary or rotationally fixed, i.e. is non-rotatable about any longitudinal axis.

The steering wheel arrangement comprises 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 rotationally stationary steering system support column or the stator, preferably with an end portion of the rotationally stationary steering system support column, so as to be non-rotatable about the central axis. By this configuration, the steering wheel center part stays stationary regarding its rotational orientation even in a condition in which the steering wheel is rotated. The steering wheel center part is completely rotationally stationary (i.e. non-rotatable). Thus, regardless of the rotational orientation of the steering wheel, the controls and if applicable signs, displays, etc. of center part are always kept in the same rotational orientation so as to be readily available to the driver and thus allow a simple, intuitive and thus safe operation of the controls in any situation.

The steering wheel center part can comprise a steering wheel center pad. More precisely, a component of the steering wheel center part, which faces the driver of the vehicle/faces away from the dashboard of the vehicle, can be formed as a steering wheel center pad. The steering wheel center part can be arranged coaxial to the steering wheel hub and to the steering wheel.

The steering wheel arrangement is column stalk control free. In other words, column stalk control free means the steering wheel arrangement, i.e. both the steering wheel and steering wheel hub, has no column stalk controls or column-mounted stalk switches provided thereon.

The steering system is configured moveable relative to the vehicle chassis and/or the vehicle dashboard, preferably at least translationally moveable, so that the steering wheel arrangement, i.e. the steering wheel, the steering wheel hub, the torque feedback device and the steering wheel center part, is reversibly retractable in a direction towards the dashboard of the vehicle and extendable in a direction away from the dashboard of the vehicle. Upon transition from manual driving to autonomous driving the steering wheel arrangement can be retracted towards the dashboard, and upon transition from autonomous driving to manual driving the steering wheel arrangement can be extended towards the driver.

The omission of column stalk controls/column-mounted stalk switches improves retractability, i.e. increases a maximum retractability of the steering wheel, as the retraction of the steering wheel is not limited by any column stalk controls/column-mounted stalk switches. This leads to space advantages within the driver cabin during autonomous driving, when the steering wheel is fully retracted.

Even though, the maximum retractability and thus a maximum retraction travel is increased by the disclosed steering system configuration, safe operability of the system is not deteriorated but is even improved by ensuring that the center part including the airbag module is rotationally stationary and does not change its rotational orientation. Even during a transition from autonomous driving to manual driving when the autonomous vehicle hands the control of the vehicle back to the driver, i.e. during transition of the steering wheel from a fully retracted state to an extended state (and reverse), the center part is rotationally stationary. Thus, ready availability of the steering wheel controls to the driver can be ensured.

Moreover, by ensuring that the center part including the airbag module is rotationally stationary and does not change its rotational orientation, effective and proper deployment of the airbag can be achieved. Thus, a steering wheel-mounted airbag can be provided and there is no need to relocate the driver-side airbag to unconventional positions, in which the airbag's effectiveness is unknown.

Consequently, the disclosed steering system configuration assures continuous availability of all controls to the driver in an intuitive manner, and assures proper deployment of the airbag, regardless of whether the steering wheel is in the manual driving position, a retracted autonomous driving position, or an intermediate transition position. This can promote acceptability and increase safety of autonomous vehicles as especially the transition from manual driving to autonomous driving, and reverse, constitute key situations, relevant for the driver.

In an embodiment, an orientation of the center part, in particular of the center pad, can be adjustable. To this, the center part can be pivotably supported inside the steering system support column so as to be pivotable about an axis traverse to the central axis. The center part can be attached to the steering system support column or the stator by a joint or hinge arrangement. Hence, while being non-rotatable (rotationally stationary) relative to the central axis, the center part can be pivotable, preferably up and down. Thus, the pivotable orientation (or up and down orientation) of the center part can be adjusted depending on or in accordance with the retraction/extension position of the steering wheel arrangement in order to keep the deployment direction of the airbag module and the steering wheel controls oriented towards the driver. The orientation of the center part, in particular of the center pad, can be automatically adjustable. The orientation of the center part, in particular of the center pad, can be passively or actively adjusta-ble. Passively adjustable can mean that the movement/pivoting of the center part is caused by an actuator that moves the steering system support column relative to the vehicle body. Actively adjustable can mean that the movement/pivoting of the center part is caused by an additional actuator that actively moves the center part mechanically independent of the movement of the steering system support column relative to the vehicle body.

In an embodiment, the steering wheel controls can include at least one or a plurality of the following controls: turn signal control/s, light control/s, horn control/s, driver aid control/s, infotainment control/s, wiper control/s and/or cruise control/s. In particular, controls that are provided in the form of column stalk controls in conventional steering wheel assemblies can be provided as steering wheel controls on the steering wheel center part, namely on the steering wheel center pad.

The steering wheel controls can have different technical configurations depending on their respective function. Individual or all of the steering wheel 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.

In an embodiment, at least one additional control and/or at least one display unit can be arranged on the steering wheel, preferably on the at least one spoke. In this case, controls (and display) can be provided both on the non-rotating and on the rotating part of the steering wheel.

However, none of the controls are configured as column stalk switches and none of the controls are arranged on a circumferential surface of the steering wheel hub. Preferably, all controls of the steering system are provided on a side of the steering system facing towards the driver, i.e. facing away from the dashboard of the vehicle. Preferably, no controls are arranged on the steering wheel arrangement between the steering wheel and the dashboard of the vehicle.

According to an embodiment, the steering system is axially moveable (and translationally movable) along the central axis so that the steering wheel arrangement is reversibly retractable in a direction towards the dashboard and extendable in a direction away from the dashboard of the vehicle. This constitutes a particularly simple configuration for enabling controlled and quick retractability of the steering system.

The steering wheel arrangement can have a retraction travel (and thus also a respective extension travel) between <NUM> and <NUM>, preferably between <NUM> and <NUM>, more preferably between <NUM> and <NUM>. Thus, the steering system is optimally adjustable to different drivers and can provide adequate space inside the driver's cabin during autonomous driving. The retraction travel can be a travel in addition to an adjustment travel for adjusting the vehicle position. The adjustment travel can be between <NUM> and <NUM>. Thus, a total axial travel can be between <NUM> and <NUM>. The total travel can even be <NUM>.

In an embodiment, the airbag module, more precisely an airbag module central axis, can be located offset from the central axis of the steering wheel arrangement. Alternatively, the airbag module, more precisely the airbag module central axis, is arranged coaxial to the central axis of the steering wheel arrangement or matches the central axis of the steering wheel arrangement.

The airbag module can be arranged on or partially inside 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. Alternatively, the airbag module, more precisely the airbag module central axis, is arranged parallel to the central axis of the steering wheel arrangement.

The position and orientation of the airbag module can be selected based on the size and shape of the other steering wheel components, such as the steering wheel rim, or based on the overall configuration of the steering wheel, in order to ensure proper deployment of the airbag.

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. Such a configuration can further contribute to increasing the maximum retractability of the steering wheel arrangement and can contribute to a harmonious design of the driver's cabin. Preferably, the rear surface can be formed such that in a completely retracted state of the steering wheel arrangement, at least <NUM> % of the rear surface of the steering wheel abuts the dashboard front surface, preferably at least <NUM> %, more preferably at least <NUM> %, still more preferably at least <NUM> %.

According to an embodiment, the rotor can be an outer rotor and the stator can be an inner stator. Accordingly, in this embodiment the steering wheel hub is fixedly attached to an outer rotor, wherein the steering wheel rim is fixedly connected with the steering wheel hub via the at least one spoke. The steering wheel rim and the at least one spoke can be formed integrally. The at least one spoke and the steering wheel hub can be formed integrally.

In an embodiment, the steering system support column can form 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. two, three or multiple piece telescope arrangement, i.e. a telescope arrangement having at least two segments or members, namely one outer segment or member and one inner segment or member. The telescope arrangement provides a simple and stiff configuration. Preferably, the tubular telescope arrangement can be a three piece telescope arrangement, i.e. a telescope arrangement having three segments or members, namely one outer segment or member, one intermediate segment or member, and one inner segment or member (which can be the steering system support column). The steering system support column can be formed by two or more fixedly connected members.

The translational movement, i.e. the sliding, of the inner member relative to the outer member of the tubular telescope arrangement can be caused by an actuator in form of an electric motor that is configured to act upon the inner member.

Preferably, the outer member of the tubular telescope arrangement can be a vehicle support column via which the steering system support column is attached to a vehicle body. The vehicle support column - and with the vehicle support column the steering wheel support column and the steering wheel arrangement attached thereto - can be adjustable relative to the vehicle body by being pivotable and/or radially displaceable relative to the vehicle body. Thus, the steering wheel arrangement is individually adjustable to different drivers.

According to an embodiment, the steering wheel rim can comprise at least one sensor, preferably a plurality of sensors, configured to detect contact of a driver's hand/fingers with the steering wheel. The steering system (or more precisely a control system of the steering system) can be configured to automatically stop retraction of the steering wheel arrangement when the retraction travel reaches a predetermined threshold value (e.g. a predefined minimal distance between the steering wheel and the dashboard) and when at the same time the at least one sensor detects that the driver's hand/fingers contacts the steering wheel. Thus, jamming of the fingers due to steering wheel retraction can be securely prevented.

According to an embodiment, the steering wheel rim can comprise at least one sensor, preferably a plurality of sensors, configured to detect contact of a driver's hand/fingers with the steering wheel. The at least one sensor can be configured to detect a predefined minimum contact of the driver's hand and/or fingers with the steering wheel that needs to be reached before the steering system (or more precisely a control system of the steering system) initiates or allows transition from autonomous driving to manual driving. Thus, it can be ensured that the driver is ready and willing to regain control of the vehicle steering. This further contributes to driver safety.

The sensor/sensors for detecting contact of a driver's hand/fingers with the steering wheel in order to prevent jamming of the driver's fingers can be the same or different sensor/sensors as/than the sensor/sensors for detecting contact of a driver's hand/fingers with the steering wheel in order to initiate or allow the transition from autonomous to manual driving.

The steering wheel rim has a non-planar shape. In other words, non-planar can mean that at least a part of the steering wheel rim lies in or spans a first plane while at least another part of the steering wheel rim lies in or spans at least one second plane which at least one second plane intersects the first plane.

At least one portion of the steering wheel rim is curved towards the dashboard of the vehicle. Thus, the at least one portion of the steering wheel rim is spaced further away from the driver compared to other non-curved parts of the steering wheel rim, which are arranged at comfortable hand positions for the driver. Hence, this at least one portion of the steering wheel rim can have an increased and preferably optimized focal distance, which is closer to the road focal distance compared the non-curved parts of the steering wheel rim.

Providing a steering wheel rim with non-planar shape is possible as the steering wheel arrangement is configured column stalk control free. Thus, there is no risk of any adverse interference of column stalk controls with the curved parts of the steering wheel rim during rotation of the steering wheel.

At least one display unit can be provided in an area of the steering wheel rim. The at least one display unit can be provided in an area of a front surface facing the driver, in particular in the at least one portion of the steering wheel rim that is curved towards the dashboard of the vehicle.

The steering wheel rim can have a non-planar configuration. A non-planar configuration can mean that the steering wheel rim comprises several sections or portions that do not lie in a common plane, more precisely in a reference plane normal to the central axis. In other words, the non-planar steering wheel rim can have a structure with several sections or portions, wherein at least one portion or section extends in each spatial direction (at least one section in x-direction, at least one section in y-direction, at least one section in z-direction). Preferably, the non-planar steering wheel rim comprises at least two sections extending substantially in x-direction, at least two sections extending substantially in y-direction, and at least two sections extending substantially in z-direction. Preferably, the non-planar steering wheel rim comprises several sections extending substantially in x-direction, several sections extending substantially in y-direction, and several sections extending substantially in z-direction. The non-planar configuration can also be described in that the steering wheel rim comprises sections adjacent to each other that are angled or inclined relative to each other in each spatial direction In other words, non-planar can mean that at least a part of the steering wheel rim lies in or spans a first plane while at least another part of the steering wheel rim lies in or spans at least one second plane which at least one second plane intersects the first plane.

The non-planar steering wheel rim can at least partially wrap around a dashboard curvature, which can lead to interior space gain. The interior space gain can be particularly recognizable in a retracted state of the steering wheel system. The non-planar steering wheel rim can be configured fully or partially complementary to an opposing part of the dashboard. Thus, in a fully retracted state, the non-planar steering wheel rim can at least partially or fully abut to one or more sections of a corresponding dashboard part.

Further, providing a non-planar steering wheel rim can lead to increased ergonomics for the driver.

The steering wheel rim can have a total angle of rotation of less than <NUM>°, preferably <NUM>° or less, more preferably <NUM>° or less, still more preferably <NUM>° or less. This total angle of rotation constitutes a reduction compared to known steering wheel arrangements. The steering wheel rim can even have a total angle of rotation of <NUM>° or less, preferably <NUM>° or less, more preferably <NUM>° or less. A reduced total angle of rotation can reduce steering effort. Further, in combination with retractability of the steering wheel arrangement, ready availability of the steering wheel during a transition from autonomous driving to manual driving when the autonomous vehicle hands the control of the vehicle back to the driver, i.e. during transition of the steering wheel from a fully retracted state to an extended state (and reverse), can be improved. Thus, it can be ensured that the driver can securely gain back control of the steering wheel in any situation, even if the transition takes place during cornering or turning.

The rotation of the steering wheel rim about its central axis can be mechanically limited to the total angle of rotation. The rotation of the steering wheel rim about its central axis can be electrically limited to the total angle of rotation.

The steering system can comprise a steering wheel rotation limiting device for at least mechanically limiting the total angle of rotation of the steering wheel rim, i.e. the total rotation of the steering wheel hub in both circumferential directions about the axis of rotation.

The torque feedback device can be configured to provide torque feedback to a driver and/or can be configured to electrically limit the total angle of rotation of the steering wheel rim.

In an embodiment, the steering wheel system can be configured (in particular the torque feedback device can be controlled) so as to provide different total angles of rotation during manual driving and during autonomous driving. The total angle of rotation can be minimized during autonomous driving and the total angle of rotation can be maximized during manual driving. A ratio between a total angle of rotation during manual driving and a total angle of rotation during autonomous driving can be at least <NUM>:<NUM>, preferably, at least <NUM>:<NUM>, more preferably at least <NUM>:<NUM>, still more preferably at least <NUM>:<NUM>, still more preferably at least can be at least <NUM>:<NUM>.

The steering wheel rim can be mirror symmetrical. In particular, the steering wheel rim can be mirror symmetrical relative to a symmetry plane which comprises the central axis of the steering wheel rim and/or steering wheel arrangement. This can further contribute to a simple regaining of steering wheel control during a transition period, even during cornering or turning situations.

The provided configuration optimally combines new and advantageous configurations with known structures which the driver is used to so as to ensure best possible driver safety.

The steering wheel rim can comprise at least one upper portion that is inclined in a direction towards the vehicle dashboard relative to a middle portion of the steering wheel rim. The steering wheel rim can comprise at least one bottom portion that is inclined in a direction towards the vehicle dashboard relative to a middle portion of the steering wheel rim. This can provide further design freedom and can further increase interior space for the occupants.

At least one portion of the steering wheel rim can be curved towards the dashboard of the vehicle. Thus, the at least one portion of the steering wheel rim is spaced further away from the driver compared to other non-curved parts of the steering wheel rim, which are arranged at comfortable hand positions for the driver. Hence, this at least one portion of the steering wheel rim can have an increased and preferably optimized focal distance, which is closer to the road focal distance compared the non-curved parts of the steering wheel rim.

The steering system can have a maximum steering ratio between <NUM>:<NUM> and <NUM>:<NUM>. The steering ratio can describe the ratio between the rotation or turn of the steering wheel arrangement (in degrees), in particular the steering wheel rim, relative to the rotation or turn of the steered wheels (in degrees). Preferably, the maximum steering ratio can be between <NUM>:<NUM> and <NUM>:<NUM>, more preferably between <NUM>:<NUM> and <NUM>:<NUM>, still more preferably between <NUM>:<NUM> and <NUM>:<NUM>. A maximum steering ratio of <NUM>:<NUM> means that operation of the vehicle would be possible without ever having to detach hands from the steering wheel, especially if switches and controls remain within reach from the steering wheel.

The steering system can have a variable steering ratio. In particular, the steering ratio can be adjustable between from between <NUM>:<NUM> and <NUM>:<NUM> to between <NUM>:<NUM> and <NUM>:<NUM>. The steering ration can be automatically adjustable during vehicle operation between from between <NUM>:<NUM> and <NUM>:<NUM> to between <NUM>:<NUM> and <NUM>:<NUM> depending on certain vehicle, driving and/or environmental conditions. In other words, the steering ratio can automatically adjust (by means of a control system) during vehicle operation. Conditions on which the adjustment depends can be current vehicle speed, current centrifugal forces, traffic volume, etc. Conditions on which the adjustment depends can be a vehicle operational state relating to an autonomous driving, a manual driving or a transitional state. The steering wheel ratio can be adjustable so that a greatest steering ratio can be between <NUM> % and <NUM> %, preferably between <NUM> % and <NUM> %, more preferably <NUM> %, higher that a lowest steering ratio.

The omission of column stalk controls/column-mounted stalk switches improves design freedom with regard to non-planar steering wheel rim structures, while contributing to safe operability. The column stalk free control free configuration of the steering wheel arrangement avoids any collision or contact between parts of the non-planar steering wheel rim (e.g. an inclined portion) and column stalk controls during rotation of the steering wheel rim. Thus, unobstructed operation of the steering wheel can be realized both during autonomous driving and during manual driving.

The absence of stalk switches allows design integration of the steering wheel in the retracted position with more space for the occupants, while at the same time allowing full steering wheel rotation because the absence of stalks eliminates the possible interferences during rotation.

According to an embodiment, the steering wheel rim can be provided with at least one display unit mounted on the steering wheel rim. In particular, the non-planar structure of the steering wheel rim can provide sections that are suitable for display unit arrangement. Preferably, the steering wheel rim can be provided with at least two display units. A plurality of display units allows displaying different information on different display units. The at least one display unit can be a touch screen. In this case, controls can be realized by the at least one display unit.

The at least one display unit can be provided in an area of a front surface facing the driver, in particular in the at least one portion of the steering wheel rim that is inclined or curved towards the dashboard of the vehicle.

In particular, the at least one display unit can be arranged on the inclined upper portion or the inclined bottom portion of the steering wheel rim. Mounting the at least one display unit on a portion inclined in a direction towards the dashboard, i.e. away from the driver, can increase the focal distance. This can contribute to optimal perceptibility of the at least one display unit, more precisely of the information and/or control displayed by the at least one display unit. Consequently, this can further increase overall passenger and driving safety.

The at least one display unit can have the shape of a circular segment. By this structural configuration, the at least one display unit can optimally integrated in an at least partially circular/ring shaped steering wheel rim.

In an embodiment, the steering wheel rim can be provided with an open top portion and/or an open bottom portion. The steering wheel rim can in these cases be configured in form of one or two open ring segment/s.

According to an embodiment, the steering system support column can include an off-axis section having a first longitudinal axis that is off-set, and preferably parallel, to the central axis of the steering wheel arrangement and can include an aligned section having a second longitudinal axis that corresponds to the central axis of the steering wheel arrangement. Corresponding to the central axis of the steering wheel arrangement can also be described as being aligned with or coaxial to the axis of rotation. The off-axis section and the aligned section can be formed by separate but fixedly connected components. The off-axis section and the aligned section can be fixedly connected by a connection portion. The connection portion can be a further separate component or can be formed integrally with the off-axis section or the aligned section. The steering wheel hub is rotatably mounted on the aligned section and thus at least partially overlaps the aligned section in an axial direction. The off-axis section is axially spaced from the steering wheel hub.

The stator of the torque feedback device can be non-rotatably fixed to the aligned section of the steering system support column.

Preferably, the aligned section can form a hub element that is stationary relative to the rotor and the steering wheel hub and that carries the inner stator of an outer rotor electric machine.

This structural design of the steering system support column including an off-axis section and an aligned axis section in combination with the torque feedback device arranged on the aligned section provides optimized use of installation space, while allowing a simple retractability of the steering wheel arrangement and at the same time reducing friction and inertia due to the torque generation/transmission.

Thus, the combination of the described steering system support column design and the torque feedback device contributes to a structurally optimized configuration.

The connection portion can extend transversally to both the first longitudinal axis and the second longitudinal axis.

The off-axis section, the aligned section and/or the connection portion can be tubular. In particular, each of the off-axis section, the aligned section and the connection portion can be tubular. The off-axis section, the aligned section and/or the connection portion can at least partially have a substantially rectangular or circular cross-section. Alternatively, the off-axis section, the aligned section and/or the connection portion can have any other cross-sectional shape. For example, the off-axis section, the aligned section and/or the connection portion can have an oval or polygon shaped cross-section. A polygon shaped cross-section can be advantageous in view of providing some flat surfaces to provide angular reference between an axially sliding part and a fixed part of a telescope arrangement, so as to prevent rotation with respect to each other around a first longitudinal axis. The shape of the cross-section of the off-axis section, the aligned section and the connection portion can be the same or can be different.

According to an embodiment, the steering system support column can comprise an opening, preferably arranged in the off-axis section or in the connection portion, which provides access to electric machine phase connections and/or steering wheel angle sensor connections which connect the electric machine and/or at least one sensor with the electronic control unit. The sensor can be the steering wheel angle sensor. Thus, a steering wheel rotation limiting device, in particular a removably attached steering wheel rotation limiting device, can enable accessibility to electrical connections for service and maintenance purposes and can at the same time securely protect the electrical connection and components from damaging environmental influences.

According to an embodiment, the steering system can comprise an electronic control unit at least for controlling the torque feedback device and/or for receiving and transmitting sensor information, such as information from the steering wheel angle sensor. The electronic control unit can be arranged inside the off-axis section of the steering system support column, preferably in an area adjacent to or following the connection portion. In this case, the electronic control unit can be arranged close to the stator windings of the torque feedback electric machine and/or close to sensor/s, such as the rotation angle sensor for measuring rotation of the electric machine rotor.

The steering wheel center part including the airbag module can be arranged at least partially inside and/or can be formed of the aligned section of the steering system support column and thus inside the stator of the torque feedback electric machine.

In an embodiment, the steering system can comprise additional auxiliary components which are arranged inside the aligned section of the steering system support column and thus inside the stator of the torque feedback electric machine. The additional auxiliary components can comprise switchgear controls, a driver display arrangement, and/or a wiring harness. By arranging the auxiliary components inside the steering system support column, installation space can be efficiently used, i.e. required overall installation space for the steering system can be reduced.

According to an embodiment, the aligned section of the steering system support column can be provided with a protruding flange portion that provides a first bearing surface for a first bearing arrangement arranged between the steering system support column and the steering wheel hub. Preferably, the protruding flange portion can be arranged in a transition region between the aligned section and the connection portion, i.e. an end portion of the aligned section facing away from a steering wheel connected or connectable with the steering system. The protruding flange portion provides a circular ring-shaped first bearing surface. By means of the protruding flange portion, the outer diameter of the main part of the aligned section can minimized, while still supporting the steering wheel hub having a substantially greater inner diameter.

The aligned section of the steering system support column can comprises a circular ring-shaped portion that provides a circular ring-shaped second bearing surface for a second bearing arrangement arranged between the steering system support column and the steering wheel hub. Preferably, the circular ring-shaped portion can be arranged at least in a region following or adjacent to the steering wheel connected or connectable with the steering system, in other words at least in a region facing away from the off-axis section and the connection portion. By means of the circular ring-shaped portion, the outer shape/contour of the main part of the aligned section can be freely chosen, while still rotatably supporting the steering wheel.

The first and the second bearing arrangement can realize rotatable support of the steering wheel hub and a steering wheel connected therewith on the steering system support column.

In an embodiment, the steering system can comprise a steering wheel rotation limiting device for at least mechanically limiting rotation of the steering wheel hub in both circumferential directions about the axis of rotation. The steering wheel rotation limiting device can be attached to the off-axis section via a base of the steering wheel rotation limiting device and can engage the steering wheel hub via a sliding element.

The base of the steering wheel rotation limiting device comprises two axially opposing end stop surfaces, and the sliding element is axially slidable parallel to the axis of rotation relative to the base and relative to the steering wheel hub between the two opposing end stop surfaces. The sliding element can comprise a projection, in particular a spiral ridge, that engages a spiral groove formed on an outer circumferential surface of the steering wheel hub so that rotation of the steering wheel hub causes axial movement of the sliding element, and so that abutment of the sliding element with one of the two end stop surfaces blocks further movement of the sliding element and thus further rotation of the steering wheel hub.

The base of the steering wheel rotation limiting device can overlap the protruding flange portion, and thus the first bearing surface, in an axial direction with respect to the axis of rotation. Thus, an advantageous compact design of the steering system structure can be realized.

The base can comprise a compartment formed therein that accommodates the sliding element and thereby inhibits radial movement of the sliding element in a direction away from the steering wheel hub and lateral movement of the sliding element transversal to a direction of its axial dis-placeability. The compartment can only allow axial movement of the sliding element between the two opposing end stop surfaces.

The base can be arranged radially adjacent to the steering wheel hub such that the base and the outer circumferential surface of the steering wheel hub completely enclose the compartment.

The steering system can be configured so that in a condition or position in which the sliding element abuts one of the two opposing end stop surfaces, the projection is still spaced from both end portions of the spiral groove, preferably by a defined distance or a defined section of the spiral groove. Hence, restriction of rotation of the steering wheel hub is not caused by an interaction of a portion of the projection with an end portion of the spiral groove, but instead by an abutment of a surface of the sliding element with one of the two end stop surfaces. Thus, the abutting surface area can be increased, compared to known solutions, which prevents damage of the steering system, in particular of the spiral groove and the projection, even under influence of strong external forces.

In an embodiment, the torque feedback device can be configured to increase the torque feedback level when a minimum distance between the sliding element and one of the two end stop surfaces falls below a predetermined threshold value. In this case, rotation of the steering wheel hub/steering wheel can be decelerated to some extend before abutment of the sliding element with one of the two end stop surfaces completely and abruptly blocks further rotation of the steering wheel hub/steering wheel. A threshold can be defined with respect to each of the two end stop surfaces.

The steering wheel can be directly or indirectly mechanically attached to the steering wheel hub by fixing elements. For example, the fixing elements can comprise bolts, screws, rivets, nuts, bonding and/or swaging (pressing and/or deforming). Preferably, a total number of three to ten screws can be arranged in equal distances around an axis of rotation of the steering wheel and steering wheel hub.

With respect to the central axis of the steering wheel arrangement, the fixing elements can be arranged at different radial positions, i.e. radial heights, than the stator windings. In other words, the fixing elements can be arranged at different radial heights compared to the stator windings when viewed with regard to the central axis of the steering wheel arrangement, i.e. the fixing elements can have different radial distances central axis of the steering wheel arrangement than the stator windings.

Providing an outer rotor electric machine for the torque feedback device and arranging the fixing elements at different radial positions than the stator windings allows for an advantageous compact design of the steer-by-wire steering system that reduces the required installation space.

A portion of the fixing elements can axially overlap a portion of the stator windings with respect to the central axis of the steering wheel arrangement. In particular, a portion of each of the fixing elements or a portion of only one or particular fixing elements can axially overlap a portion of the stator windings with respect to the central axis of the steering wheel arrangement. Such an arrangement is possible by means of the arrangement of the fixing elements at different radial positions than the stator windings. Thus, at least portions of the fixing elements can be arranged parallel to the stator windings, which further contributes to a compact structure of the steering system.

With respect to the central axis of the steering wheel arrangement, the fixing elements can be arranged at different radial positions than the first bearing arrangement; and/or the fixing elements can be arranged at different radial positions than the second bearing arrangement. Such arrangements can also enable an overlapping/parallel arrangement of components of the steering system, which further contributes to a compact design and reduced installation space requirements of the steering system.

Another aspect relates to an arrangement comprising a steering system of the type described above and a dashboard for a vehicle.

A front surface of the dashboard can be formed at least partially complementary to a rear surface of the steering wheel. Thus, opposing surfaces of the dashboard and of the steering wheel can be formed at least partially complementary. Such a configuration can further contribute to increasing the maximum retractability of the steering wheel arrangement and can contribute to a harmonious design of the driver's cabin.

In an embodiment, the steering wheel hub can be at least partially or completely retractable into a corresponding recess formed in the dashboard.

Even though some of the features, functions, embodiments, technical effects and advantages have been described with regard to one aspect, it will be understood that these features, functions, embodiments, technical effects and advantages can be combined with one another also applying to other embodiments and aspects.

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

<FIG> show schematic views of a steering system <NUM> for an autonomous road vehicle according to an example useful for understanding the invention. As can be seen in <FIG>, the steering system <NUM> is a steer-by-wire steering system that has no direct mechanical connection for transferring a driver's steering commands from a steering wheel <NUM> of the steering system <NUM> to the wheels (not shown) of the vehicle. Instead, the mechanical connections are replaced by an electro-mechanical arrangement.

The steering system <NUM> comprises a steering wheel arrangement <NUM> with the steering wheel <NUM> and steering wheel hub <NUM> mechanically connected with the steering wheel <NUM>. The steering wheel hub <NUM> and the steering wheel <NUM> are non-rotatable relative to each other, but can be rotated together about a central axis A of the steering wheel arrangement <NUM>. As can be seen, steering wheel <NUM> comprises a ring-shaped rim <NUM> and, in the shown example, three spokes <NUM> that connect the steering wheel rim <NUM> with the steering wheel hub <NUM>.

The steering wheel arrangement <NUM> further includes a torque feedback device for generating torque feedback to the driver. The torque feedback device is housed inside the steering wheel hub <NUM> and is thus not shown in <FIG> (but shown and denoted with reference sign <NUM> in <FIG>).

The steering wheel arrangement <NUM> comprises a steering wheel center part <NUM> (shown in more detail in and described in connection with <FIG>). The steering wheel center part <NUM> is rotationally stationary and is non-rotatably fixed to an end portion of the steering support column <NUM>. The steering wheel center part <NUM> 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.

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

As can be seen in <FIG>, the steering wheel arrangement <NUM> is completely column stalk control free. In other words, the steering wheel arrangement <NUM> has no column stalk switches or levers arranged thereon. More precisely, the steering wheel hub <NUM> is completely column stalk control free. Thus, the steering system <NUM> has no column stalk controls that could block or limit retractability of the steering wheel arrangement <NUM>. In the present embodiment, conventional column stalk controls are replaced by steering wheel controls (see <FIG>) arranged on the steering wheel center part <NUM>, more precisely on a surface of a steering wheel center pad <NUM> facing the driver. In the steering system, no controls are arranged between a rear surface of the steering wheel <NUM> 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).

<FIG> show the front view of the steering wheel arrangement <NUM> in more detail and with different rotational orientations. More precisely, the steering wheel <NUM> has different rotational orientations in <FIG>. In <FIG> the steering wheel <NUM> is in a basic position in which the steering wheel <NUM> 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> shows the steering wheel <NUM> in a certain rotated position in which the steering wheel <NUM> 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 <NUM>.

As can be seen in <FIG>, the center part <NUM> of the steering wheel arrangement <NUM> is rotationally stationary, i.e. is non-rotatable about the central axis A. Even if the steering wheel <NUM> is rotated, the center part <NUM> stays in its basic, non-rotated orientation. Therefore, regardless of a current driving situation and a current rotational orientation of the steering wheel <NUM>, the controls arranged on the center part <NUM> 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.

The center part <NUM>, more precisely the center pad <NUM>, 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 <NUM>. The turn and light signal controls 104A and 104B replace conventional turn and light signal column stalk control levers. The center pad <NUM> is further provided with driver aid and cruise controls <NUM> and wiper controls <NUM>. Further, a horn control is provided on the center pad <NUM>. In the shown embodiment, two alternative horn control positions 110A and 110B are shown.

Besides the steering wheel controls 104A to 110B arranged on the center pad <NUM> of the center part <NUM>, additional controls are provided on spokes <NUM> of the steering wheel <NUM>. In the present embodiment, further driver aid controls <NUM> and infotainment controls <NUM> are provided on the spokes <NUM>.

Moreover, controls can also be arranged on the steering wheel rim <NUM>. In the shown embodiment, alternative horn control positions 210A and 210B are shown.

The steering wheel controls 104A to 110B as well as the additional controls 210A, 210B, <NUM>, <NUM> can have different technical configurations depending on their respective function. 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.

<FIG> show the steering system <NUM> in retracted positions (<FIG>) and in extended positions (<FIG>) according to an example not covered by the subject matter of the appended claims. Further, the contour of a dashboard of the vehicle is schematically indicated by line <NUM>. The contour of the dashboard is shown in comparison to a conventional dashboard design contour indicated by dashed line <NUM>. The omission of column stalk levers in the present steering wheel arrangement <NUM> allows new dashboard design options. For example, as shown in <FIG>, an extension of the dashboard <NUM> can be increased in direction towards the driver/in direction towards the steering wheel <NUM> - compared to conventional dashboards - while 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 example, 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.

<FIG> show the steering system <NUM> in retracted positions together with an alternative dashboard design. The alternative dashboard design further includes an additional extension part <NUM> so that in a retracted state of the steering wheel arrangement <NUM>, the dashboard and the steering wheel <NUM> at least partially abut. Preferably, the dashboard and the steering wheel <NUM> can be formed at least partially complementary so as to allow optimal abutment.

<FIG> shows a schematic perspective view of the steering system <NUM> according to an embodiment of the invention. The embodiment shown in <FIG> substantially corresponds to the embodiment shown in <FIG>. Yet, unlike the embodiment of <FIG>, the embodiment of <FIG> comprises a steering wheel rim <NUM> having a non-planar structure relating to a planar reference plane RP. The steering wheel rim <NUM> is formed as a substantially circular, ring shaped, closed structure forming a grip portion to the vehicle driver. The non-planar steering wheel rim <NUM> comprises an upper portion <NUM> that is inclined in a direction towards the vehicle dashboard <NUM> relative to a middle portion <NUM> of the steering wheel rim <NUM>. The steering wheel rim <NUM> comprises a bottom portion <NUM> that is inclined in a direction towards the vehicle dashboard <NUM> relative to the middle portion <NUM> of the steering wheel rim <NUM>.

The steering wheel rim <NUM> of <FIG> can have a total angle of rotation of <NUM>°. The total angle of rotation can be mechanically limited by a rotation limiting device <NUM> as shown in <FIG>.

<FIG> show the steering system <NUM> of <FIG> in retracted positions together with a dashboard design. The dashboard design includes an additional extension part <NUM> so that in a retracted state of the steering wheel arrangement <NUM>, the dashboard and the steering wheel <NUM> at least partially abut. Preferably, the dashboard and the steering wheel <NUM> can be formed at least partially complementary so as to allow optimal abutment. As can be seen in <FIG>, the non-planar steering wheel rim <NUM> at least partially wraps around a dashboard curvature, which leads to interior space gain (indicated by arrows SG).

The steering system <NUM> is configured completely column stalk control free.

<FIG> show a steering system <NUM> according to another example not covered by the subject matter of the appended claims. Steering system <NUM> of <FIG> substantially corresponds to steering system <NUM> of <FIG>. Steering system <NUM> is provided with a display unit <NUM> mounted on the steering wheel rim <NUM>. More precisely, the display unit <NUM> is arranged on the inclined upper portion <NUM> of the steering wheel rim <NUM>. This increases a focal distance FD relating to the display unit <NUM>, which contributes to optimal perceptibility of the display unit <NUM>.

A further example of a steering system <NUM> not covered by the subject matter of the appended claims is shown in <FIG>. In contrast to the example of <FIG>, the steering system <NUM> of <FIG> is provided with an open top portion <NUM>. Nonetheless, the overall structure of the steering wheel rim <NUM> is mirror symmetrical in this and all other shown examples (this is not necessary but preferable). By providing the steering wheel rim <NUM> with an open top portion <NUM>, the steering wheel rim <NUM> in this example consequently comprises two inclined upper portions <NUM>, one on each side of the open top portion <NUM>.

A further example of a steering system <NUM> not covered by the subject matter of the appended claims is shown in <FIG>. In contrast to the example of <FIG>, the steering system <NUM> of <FIG> is provided with an open bottom portion <NUM>. Nonetheless, the overall structure of the steering wheel rim <NUM> is mirror symmetrical in this and all other shown examples (this is not necessary but preferable). By providing the steering wheel rim <NUM> with an open bottom portion <NUM>, the steering wheel rim <NUM> in this example consequently comprises two inclined bottom portions <NUM>, one on each side of the open top portion <NUM>.

Even though, no display unit is shown in the examples of <FIG>, a display unit (e.g. as shown in <FIG>) could be provided on the steering wheel rim <NUM>, in particular on the respective closed inclined upper or bottom portion.

<FIG> shows a further example of a steering system <NUM> not covered by the subject matter of the appended claims. In contrast to the example of <FIG>, the steering system <NUM> of <FIG> is provided with an open top portion <NUM> and an open bottom portion <NUM>. Nonetheless, the overall structure of the steering wheel rim <NUM> is mirror symmetrical in this and all other shown examples (this is not necessary but preferable). By providing the steering wheel rim <NUM> with an open top portion <NUM> and an open bottom portion <NUM>, the steering wheel rim <NUM> in this example consequently comprises two inclined upper portions <NUM>, one on each side of the open top portion <NUM>, and two inclined bottom portions <NUM>, one on each side of the open top portion <NUM>.

<FIG> show schematic views of a steering system <NUM> with additional features according to an example not covered by the subject matter of the appended claims. As can be seen in <FIG>, the steering system <NUM> is a steer-by-wire steering system that has no direct mechanical connection for transferring a driver's steering commands from a steering wheel <NUM> of the steering system <NUM> to the wheels (not shown) of the vehicle. Instead, the mechanical connections are replaced by an electro-mechanical arrangement.

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

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

The off-axis section <NUM> and the aligned section <NUM> are fixedly connected by a connection portion <NUM> extending transversally to both the first longitudinal axis L1 and the second longitudinal axis L2.

The steering wheel hub <NUM> is rotatably mounted on the aligned section <NUM> of the steering system support column <NUM> by a first bearing arrangement <NUM> and a second bearing arrangement <NUM>, the second bearing arrangement <NUM> being axially spaced from the first bearing arrangement <NUM>. For example, the first bearing arrangement <NUM> and/or the second bearing arrangement <NUM> can be a ball bearing or a roller bearing.

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

The second bearing arrangement <NUM> is supported on a circular ring-shaped portion <NUM> of the aligned section <NUM> of the steering system support column <NUM>. The circular ring-shaped portion <NUM> is formed in an area of the aligned section <NUM> following the steering wheel <NUM> and extending towards the protruding flange portion <NUM>. The circular ring-shaped portion <NUM> provides a second bearing surface for the second bearing arrangement <NUM>. Thus, the second bearing arrangement <NUM> is axially located at a second end portion of the aligned section <NUM> opposing the first end portion.

The first bearing arrangement <NUM> is mounted between the protruding flange portion <NUM> of the aligned section <NUM> and the steering wheel hub <NUM> via a support bushing <NUM> arranged between the first bearing arrangement <NUM> and the inner circumferential surface of the steering wheel hub <NUM>.

The second bearing arrangement <NUM> is mounted directly between the circular ring-shaped portion <NUM> of the aligned section <NUM> and the steering wheel hub <NUM>. To this, the steering wheel hub <NUM> is provided with an inwardly protruding flange portion <NUM> that provides a counter bearing surface for the second bearing arrangement <NUM>. At the same time, the inwardly protruding flange portion <NUM> covers components located inside the steering wheel hub <NUM>. As can be seen in <FIG>, the blind holes <NUM> for receiving the fixing elements <NUM> extend into or through the inwardly protruding flange portion <NUM>.

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

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

The electric machine of the torque feedback device <NUM> is arranged inside the steering wheel hub <NUM>. The torque feedback device <NUM> is radially enclosed and thus covered by the steering wheel hub <NUM> (the inner circumferential surface of the steering wheel hub <NUM>) and the aligned section <NUM> of the steering system support column <NUM> (the outer circumferential surface of the aligned section <NUM>). The torque feedback device <NUM> is axially located between the protruding flange portion <NUM> of the aligned section <NUM> and the circular ring-shaped portion <NUM> of the aligned section <NUM>. The torque feedback device <NUM> is axially enclosed and thus covered by the protruding flange portion <NUM> of the aligned section <NUM>, the first bearing arrangement <NUM> and the support bushing <NUM> on one side and by the inwardly protruding flange portion <NUM> of the steering wheel hub <NUM> and the second bearing arrangement <NUM> on the other side.

The arrangement, configuration and support of the steering wheel hub <NUM>, the steering wheel <NUM>, the torque feedback device <NUM> and the steering system support column <NUM> provides a very compact structure. More precisely, as shown in <FIG>, various components are arranged at least partially parallel to each other, with respect to their radial and/or axial arrangement.

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

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

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

The fixing elements <NUM> are arranged at similar radial positions as the outer rotor <NUM> of the torque feedback device <NUM>, with respect to the central axis A. This limits the radial extension of the steering system <NUM> in the region of the torque feedback device <NUM>.

The steering system <NUM> further comprises a steering wheel rotation limiting device <NUM> for limiting rotation of the steering wheel hub <NUM> and the steering wheel <NUM>. The steering wheel rotation limiting device <NUM> is fixed to the steering system support column <NUM> and is arranged radially off-set to the steering wheel hub <NUM>, more precisely adjacent to the outer circumferential surface of the steering wheel hub <NUM>. The steering wheel rotation limiting device <NUM> is non-rotatable relative to the steering system support column <NUM>.

The steering wheel rotation limiting device <NUM> comprises a base <NUM> and a sliding element <NUM> arranged inside a compartment <NUM> formed in the base <NUM>. The sliding element <NUM> is axially slidable relative to the base <NUM> and relative to the steering wheel hub <NUM>. The sliding element <NUM> can slide between the two opposing end stop surfaces <NUM>, <NUM> (see <FIG>) of the steering wheel rotation limiting device <NUM>. The sliding element <NUM> comprises a projection <NUM> that engages a spiral groove <NUM> formed on the outer circumferential surface of the steering wheel hub <NUM>. By the interaction of the projection <NUM> and the spiral groove <NUM>, rotation of the steering wheel hub <NUM> causes axial movement of the sliding element <NUM>. Likewise, abutment of the sliding element <NUM> with one of the two end stop surfaces <NUM>, <NUM> blocks further movement of the sliding element <NUM> in a certain direction and thus blocks further rotation of the steering wheel hub <NUM> in a certain direction of rotation. Hence, the steering wheel rotation limiting device <NUM> is configured to restrict rotation of the steering wheel hub <NUM> and of the steering wheel <NUM> connected therewith.

The base <NUM> of the steering wheel rotation limiting device <NUM> is fixed to the off-axis section <NUM> of the steering system support column <NUM> by screws <NUM> (see <FIG>). The steering wheel rotation limiting device <NUM>, more precisely the base <NUM>, extends in the axial direction from the off-axis section <NUM> of the steering system support column <NUM> to the steering wheel hub <NUM> so that the compartment <NUM> is arranged between and enclosed by the base <NUM> and the outer circumferential surface of the steering wheel hub <NUM>.

Functions and further details of the steering wheel rotation limiting device <NUM> will be described in the context of <FIG>.

The base <NUM> of the steering wheel rotation limiting device <NUM> covers an opening <NUM> configured in the off-axis section <NUM> of the steering system support column <NUM>. More precisely, the opening <NUM> is arranged in another transition region between the off-axis section <NUM> and the connection portion <NUM>. The opening <NUM> provides access to electric machine phase connections <NUM> and to electric steering wheel angle sensor connections <NUM> for service and maintenance purposes. The electric machine phase connections <NUM> connect the electric machine of the torque feedback device <NUM> with a control unit/control electronics <NUM>. The electric steering wheel angle sensor connections <NUM> connect a steering wheel angle sensor <NUM> with the control unit/control electronics <NUM>.

The control unit <NUM> is arranged inside the hollow tubular off-axis section <NUM> of the steering system support column <NUM>. More precisely, the control unit <NUM> is arranged in a portion of the off-axis section <NUM> close to the connection portion <NUM> so as to locate the control unit <NUM> and the electric machine close to each other.

The steering wheel angle sensor <NUM> 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 <NUM> is arranged adjacent or lateral to the first bearing arrangement <NUM>.

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

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

The steering system support column <NUM> has a hollow tubular shape. The steering system support column <NUM> is formed as a rigid one-piece component and is preferably made of metal. As can be seen in <FIG>, which show different perspective views of the steering system <NUM>, at least the off-axis section <NUM> of the steering system support column <NUM> has a substantially rectangular cross-sectional area. Such a shape can be particularly advantageous for accommodating and attaching the control unit <NUM>. Similar to the off-axis section <NUM>, the vehicle support column <NUM> that forms the tubular telescope arrangement <NUM> together with the off-axis section <NUM> has a substantially rectangular cross-sectional area.

The connection portion <NUM> of the steering system support column <NUM> forms a tapering transition that tapers from the off-axis section <NUM> towards the aligned section <NUM>. The aligned section <NUM> has a smaller diameter than the off-axis section <NUM>. The aligned section <NUM> has a substantially circular cross-sectional area.

As can be further seen, the steering wheel <NUM> is provided with an internal space <NUM> for accommodating the center part (not shown, but shown and denoted with reference sign <NUM> in <FIG>). The center part as well as auxiliary components, such as a wiring harness, can extend into the hollow, tubular aligned section <NUM>. The center part as well as the auxiliary components can thus be arranged in and/or attached to the inside of the aligned section <NUM> of the steering system support column <NUM>.

<FIG> serve to disclose details concerning the function and configuration of the steering wheel rotation limiting device <NUM>. <FIG> shows the components of the steering wheel rotation limiting device <NUM> separately, i.e. in an exploded view. <FIG> shows the components of the steering wheel rotation limiting device <NUM> in an assembled state. <FIG> shows the steering wheel rotation limiting device <NUM> mounted to or in interaction with the steering wheel hub <NUM>.

As can be seen in <FIG>, four screws <NUM> extend through base <NUM> so as to securely fix the steering wheel rotation limiting device <NUM> to the steering system support column <NUM>. The base <NUM> has a compartment <NUM> formed therein. Two axially opposing side surfaces of the compartment <NUM> constitute the end stop surfaces <NUM>, <NUM>. The compartment <NUM> is formed partially complementary to the sliding element <NUM> that can be arranged therein (see <FIG>). Thus, the compartment <NUM>, more precisely the bottom and the lateral surfaces of the compartment <NUM>, restricts movability of the sliding element <NUM> to an axial slidability between the two end stop surfaces <NUM>, <NUM> (indicated by arrows AS). The two end stop surfaces <NUM>, <NUM> limit the slidability of the sliding element <NUM> in the axial directions. When the sliding element <NUM> abuts one of the two end stop surfaces <NUM>, <NUM>, its further movement in the current direction is blocked and the sliding element <NUM> can only move in an opposite axial direction, i.e. towards the respective opposing end stop surface <NUM>, <NUM>. A surface oriented towards the steering wheel hub <NUM>, in a mounted state, is curved and substantially complementary to a corresponding part of the outer circumferential surface of the steering wheel hub <NUM>.

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

As indicated in <FIG>, the sliding element <NUM> has an axial width W. The axial width W of the sliding element <NUM> determines the free space inside the compartment <NUM> between the sliding element <NUM> and the end stop surfaces <NUM>, <NUM>. Thus, by adapting or choosing the axial width W of the sliding element <NUM>, the maximum travel distance, i.e. the maximum axial movability, of the sliding element <NUM> between the two end stop surfaces <NUM>, <NUM> is adjustable. Thus, by merely replacing the sliding element <NUM> and adapting its axial width W and the dimensions and geometry of the projection <NUM>, the steering wheel rotation limiting device <NUM> 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 <NUM>, a pitch of the spiral groove <NUM>, a distance between the two opposing end stop surfaces <NUM>, <NUM>, and a circumferential length of the steering wheel hub <NUM>.

Claim 1:
Steering system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) for a vehicle, in particular for an autonomous vehicle, the steering system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) comprising a steering system support column (<NUM>) and a steering wheel arrangement (<NUM>) having a central axis (A); wherein the steering wheel arrangement (<NUM>) includes
a steering wheel (<NUM>) having a steering wheel rim (<NUM>, <NUM>) and at least one spoke (<NUM>),
a steering wheel hub (<NUM>) fixedly connected with the steering wheel (<NUM>) and extending from the steering wheel (<NUM>) towards a dashboard (<NUM>) of the vehicle, the steering wheel hub (<NUM>) and the steering wheel (<NUM>) being rotatable about the central axis (A),
a torque feedback device (<NUM>) including an electric machine having a rotor (<NUM>) and a stator (<NUM>), the rotor (<NUM>) being attached to the steering wheel hub (<NUM>) and being rotatable about the central axis (A), and the stator (<NUM>) being fixedly attached to the steering system support column (<NUM>) which is non-rotatable about the central axis (A),
a steering wheel center part (<NUM>) including an airbag module arranged inside the steering wheel center part (<NUM>) and being provided with a plurality of steering wheel controls (104A to 110B), the steering wheel center part (<NUM>) being fixedly connected with the steering system support column (<NUM>) or the stator so as to be non-rotatable about the central axis (A);
wherein the steering wheel arrangement (<NUM>) is column stalk control free, and wherein the steering system (<NUM>, <NUM>, <NUM>, <NUM>, <NUM>, <NUM>) is moveable so that the steering wheel arrangement (<NUM>) is reversibly retractable in a direction towards the dashboard (<NUM>) of the vehicle and extendable in a direction away from the dashboard (<NUM>) of the vehicle,
wherein a rear surface of the steering wheel (<NUM>) that faces the dashboard (<NUM>) of the vehicle is formed at least partially complementary to a dashboard front surface facing the rear surface of the steering wheel (<NUM>), and the steering wheel rim (<NUM>) has a non-planar shape, wherein at least one portion of the steering wheel rim (<NUM>) is curved towards the dashboard (<NUM>) of the vehicle.