Steer-by-wire steering system including steering wheel rotation limiter

Abstract

The present disclosure relates to a steering system (10) comprising a steering wheel rotation limiting device (52) arranged radially offset relative to the steering wheel hub (14) and comprising a base (54) fixed to the or another non-rotatable component (26) of the steering system (10), the base (54) comprising two opposite end stop surfaces (60, 62) and comprising a sliding element (56) axially slidable between the two opposite end stop surfaces (60, 62) relative to the base (54) and relative to the steering wheel hub (14) parallel to the axis of rotation. The sliding element (56) includes a protrusion (64) that engages a spiral groove (66) formed on the peripheral surface of the steering wheel hub (14) so ​​that rotation of the steering wheel hub (14) causes axial movement of the sliding element (56) and so that abutment of the sliding element (56) with one of the two end stop surfaces (60, 62) prevents movement of the sliding element (56) and rotation of the steering wheel hub (14).

Description

[0001] The invention relates to a steer-by-wire steering system for a vehicle, in particular a motor vehicle, comprising a steering wheel rotation limiting device. Background Art

[0002] In the automotive and truck industries, there is increasing interest in and use of drive-by-wire systems, where mechanical components are replaced by electromechanical configurations. Progress toward fully electric and autonomous vehicles has further fueled the development of drive-by-wire steering systems and increased the need for inventive concepts.

[0003] A specific subcategory of drive-by-wire systems involves steer-by-wire systems, which aim to replace the conventional mechanical components used to transmit the driver's steering commands from the steering wheel to the wheels with an electromechanical configuration. Such electromechanical steer-by-wire configurations can partially or completely eliminate the direct or indirect mechanical connection between the steering wheel and the steering wheels. Instead of using mechanical power transmission, steering commands are detected by a sensor arrangement and transmitted via a control unit in the form of control signals to an electromechanical actuator configured to execute the steering commands.

[0004] The steer-by-wire configuration opens up completely new possibilities in terms of installation space, assembly of the steering system, safety and design concept.

[0005] For example, a steer-by-wire steering system is known from document US 2020 / 0070871A, which discloses a vehicle steering wheel assembly, which includes a steering wheel, a control component, a rotation measuring component for measuring the rotation state of the steering wheel, and a road sensing simulator for applying a resistance torque to the rotation of the steering wheel according to the rotation state of the steering wheel. A steering column is arranged below the steering wheel, wherein the upper end of the steering column is connected to the steering wheel, and the lower end of the steering column is connected to the road sensing simulator. The road sensing simulator is fixed to the body of the vehicle. The rotation measuring component and the road sensing simulator are both connected to the control component, and the control component controls the road sensing simulator to apply a resistance torque to the rotation of the steering wheel based on the measurement data of the rotation measuring component.

[0006] Furthermore, document JP 2019-214360A discloses a steer-by-wire type power steering apparatus that is provided with a specific operating range limit adjustment device for replacing a given mechanical end stop present in a conventional steering system.

[0007] Prior art steer-by-wire systems generally have a complex structure and are limited with respect to their functionality and their applicability and adaptability to different vehicle requirements.

[0008] It is an object of the present invention to provide a steering system having improved characteristics and overcoming at least some of the disadvantages of the prior art.

[0009] In particular, it is an object of the present invention to provide a robust and reliable solution for limiting the maximum rotation angle in a steer-by-wire system.

[0010] These objects are achieved by the subject-matter of the independent claims.Preferred embodiments and preferred features are specified in the dependent claims and in the following description. Summary of the Invention

[0011] The present invention relates to a steering system for a vehicle, and more particularly, to a steer-by-wire type steering system.

[0012] The steering system may include a steering wheel hub connected or connectable to the steering wheel. The steering wheel hub is rotatable about a rotation axis. Therefore, the connected steering wheel can also rotate along with the steering wheel hub about the rotation axis. In particular, the steering wheel hub may be rotatably mounted on a steering system support column.

[0013] The steering system may comprise a steering wheel, which preferably includes a handle portion.

[0014] The steering wheel can be mechanically attached to the steering wheel hub directly or indirectly via fixing elements, which can be, for example, bolts, screws, rivets, nuts, adhesives and / or swaging (extrusion and / or deformation).

[0015] The steering system may include a torque feedback device comprising an electric motor having a rotor and a stator with stator windings, the rotor being fixedly attached to a steering wheel hub so as to be rotatable together with the steering wheel hub about a rotation axis, and the stator being fixedly attached to a non-rotatable component of the steering system. In other words, non-rotatable means that the stator is rotationally stationary or rotationally fixed relative to the vehicle body. The torque feedback device is operable to generate a resistive torque to rotation of the steering wheel, thereby simulating the resistive torque present in a conventional steering system.

[0016] The rotor may be an outer rotor and the stator may be an inner stator.

[0017] The fixing element can be arranged at a different radial position, ie at a different radial height, relative to the rotation axis than the stator winding.

[0018] The steering system may include a rigid steering system support column, the support column including an eccentric section having a first longitudinal axis, the first longitudinal axis being offset and preferably parallel to the axis of rotation, the support column also including an alignment section having a second longitudinal axis, the second longitudinal axis corresponding to the axis of rotation. Corresponding to the axis of rotation can also be described as being aligned or coaxial with the axis of rotation. The steering wheel hub can be rotatably mounted on the alignment section and can therefore at least partially overlap the alignment section in an axial direction. The eccentric section can be axially spaced or displaced from the steering wheel hub.

[0019] The eccentric section and the alignment section may be integrally formed and connected by a connecting portion. The connecting portion is a rigid portion that is also integrally formed with the eccentric section and the alignment section, ie formed in a single piece.

[0020] The steering system may include a steering wheel rotation limiting device for mechanically limiting the rotation of a steering wheel hub, thereby limiting the rotation of a steering wheel connected thereto. The steering wheel rotation limiting device may be configured to limit the rotatability of the steering wheel hub in two circumferential directions about the axis of rotation. The steering wheel rotation limiting device may be configured to still allow the steering wheel hub to rotate beyond 360°. The steering wheel rotation limiting device may be arranged radially offset and preferably adjacent to the steering wheel hub.

[0021] The steering wheel rotation limiting device may include a base fixed to the or another non-rotatable component of the steering system. The base includes two axially opposed end stop surfaces. The steering wheel rotation limiting device may include a sliding element that is slidable axially relative to the base and relative to the steering wheel hub parallel to the axis of rotation between the two opposed end stop surfaces. In other words, the sliding element can slide back and forth between the two opposed end stop surfaces.

[0022] The sliding element may include a protrusion that engages with a helical groove formed on a peripheral surface of the steering wheel hub, preferably an outer peripheral surface, such that rotation of the steering wheel hub causes axial movement of the sliding element. Thus, abutment of the sliding element with one of the two end stop surfaces prevents further axial movement of the sliding element in one direction, thereby preventing rotation of the steering wheel hub.

[0023] The steering wheel rotation restriction device may be attached to the eccentric section via a base of the steering wheel rotation restriction device and may engage the steering wheel hub via a sliding element. Thus, the steering wheel rotation restriction device may extend axially towards the steering wheel hub.

[0024] According to one aspect, a steering system for a vehicle comprises a steering wheel hub connected or connectable to a steering wheel, wherein the steering wheel hub and thus the connected or connectable steering wheel are rotatable about a rotational axis.

[0025] The steering system includes a torque feedback device including an electric motor having a rotor and a stator, the rotor being attached to the steering wheel hub so as to be rotatable together with the steering wheel hub about the rotation axis, and the stator being fixed to a non-rotatable component of the steering system.

[0026] The steering system includes a steering wheel rotation limiting device for limiting rotation of a steering wheel hub. Specifically, the steering wheel rotation limiting device is configured to mechanically limit or prevent rotation of the steering wheel hub in two circumferential directions about an axis of rotation. Thus, the steering wheel rotation limiting device is configured to at least mechanically limit or prevent rotation of a steering wheel connected to the steering wheel hub. The steering wheel rotation limiting device can also allow the steering wheel hub and steering wheel to rotate beyond 360°. The steering wheel rotation limiting device is arranged radially offset from the steering wheel hub and preferably adjacent to the steering wheel hub. The steering wheel rotation limiting device includes a base fixed to the steering system or, preferably, another non-rotatable component. The base includes two axially opposed end stop surfaces about a longitudinal axis parallel to the axis of rotation. The steering wheel rotation limiting device also includes a sliding element that is axially slidable relative to the base and relative to the steering wheel hub, parallel to the axis of rotation. The sliding element is slidable back and forth between the two opposing end stop surfaces.

[0027] The sliding element includes a protrusion that engages with a helical groove formed on the peripheral surface of the steering wheel hub. Rotation of the steering wheel hub causes axial movement of the sliding element, and contact of the sliding element with one of two end stop surfaces prevents both movement of the sliding element and rotation of the steering wheel hub. The peripheral surface of the steering wheel hub provided with the helical groove can be an outer peripheral surface. More specifically, when the steering wheel hub rotates, the interaction and engagement of the protrusion and the helical groove causes the helical groove to drag the protrusion, thereby moving the sliding element. The sliding element can then slide unless it is blocked by one of the two end stop surfaces. Contact of the sliding element with one of the two end stop surfaces prevents further movement of the sliding element in one direction. Consequently, the interaction between the protrusion and the helical groove also prevents further rotation of the steering wheel hub in one rotational direction. Thus, contact of the sliding element with one of the two end stop surfaces limits / constrains / stops the rotational movement of the steering wheel hub and the steering wheel fixedly connected thereto. In other words, the steering wheel rotation limiting device defines and constrains the maximum rotation angle of the steering system about the rotation axis.

[0028] A steering wheel rotation limiting device which limits the rotation of the steering wheel hub based on abutment of a sliding element with one of two opposite end stop surfaces while allowing the steering wheel hub to rotate more than 360° allows avoiding oversizing of the motor of the torque feedback device because the motor does not need to provide the full stop torque.

[0029] A steering wheel rotation limiting arrangement which constrains rotation of the steering wheel hub based on abutment of a sliding element with one of two opposing end stop surfaces represents a robust and reliable solution for providing a mechanical end stop function in a steer-by-wire system which does not include any natural end stop structure.

[0030] Furthermore, the base and sliding element arrangement has low complexity and can be easily manufactured and attached to the steering system.

[0031] A steering system comprising such a steering wheel rotation restriction can be flexibly integrated into different vehicles and can be easily adapted to different vehicle requirements.

[0032] The steering system may include a steering wheel.

[0033] In one embodiment, the base may include a compartment formed therein that accommodates the sliding element and thereby inhibits or prevents radial movement of the sliding element in a direction away from the steering wheel hub and inhibits or prevents lateral movement of the sliding element transverse to the direction of its axial mobility. In other words, the compartment can be configured to only allow the sliding element to move axially between two opposing end stop surfaces. The compartment can be partially complementary to the sliding element so as to inhibit radial movement of the sliding element in a direction away from the steering wheel hub and prevent lateral movement of the sliding element transverse to the direction of its axial mobility. The compartment can be a cuboid recess having five side surfaces, two of which define two end stop surfaces. Only the side of the cuboid recess facing the steering wheel hub is not closed by the side surfaces, but is open to accommodate the sliding element and allow the sliding element (protrusion) to engage with the spiral groove.

[0034] The base may be disposed radially adjacent the steering wheel hub such that the base and an outer peripheral surface of the steering wheel hub completely surround the compartment.

[0035] According to one embodiment, the steering system can be configured such that, in a state or position in which the sliding element abuts one of the two opposing end stop surfaces, the protrusion remains spaced apart from the two end portions of the helical groove, preferably by a defined distance or a defined segment of the helical groove. Consequently, the rotational restraint of the steering wheel hub is not caused by the interaction of a portion of the protrusion with the end portion of the helical groove, but rather by the abutment of the surface of the sliding element with one of the two end stop surfaces. Consequently, the abutment surface area can be increased compared to known solutions, which prevents damage to the steering system, in particular to the helical groove and the protrusion, even under the influence of strong external forces.

[0036] The sliding element may have a generally rectangular cross-section. The protrusion may be a spiral ridge projecting from the sliding element toward the steering wheel hub. The spiral ridge may be adapted to the spiral groove, particularly with respect to the pitch of the spiral groove. The spiral ridge may be substantially complementary to a portion of the spiral groove.

[0037] The axial width of the sliding element can be adapted based on one or more of the following parameters: the length of the helical groove, the pitch of the helical groove, the distance between the two opposing end stop surfaces, and the circumferential length of the steering wheel hub. By adjusting or selecting the axial width of the sliding element, the maximum travel distance of the sliding element between the two end stop surfaces, i.e., the maximum axial mobility, can be defined. Thus, by simply replacing the sliding element and adjusting its axial width and the size and geometry of the protrusion, the steering wheel rotation restriction device can be flexibly adapted to different vehicle configurations.

[0038] The steering wheel rotation restriction device can be attached to the or preferably other non-rotatable component of the steering system by means of screws, bolts, rivets or adhesive, or can be welded to the or other non-rotatable component of the steering system. Attachment by means of screws or bolts can be advantageous because the steering wheel rotation restriction device can thus be detachably mounted on the steering system.

[0039] In one embodiment, the base of the steering wheel rotation limiter can cover an opening in the non-rotatable component or another non-rotatable component, which provides access to electrical connections connecting the motor and / or at least one sensor to the electronic control unit. The sensor can be a steering wheel angle sensor. Thus, the steering wheel rotation limiter, particularly a removably attachable one, can provide access to the electrical connections for service and maintenance purposes while safely protecting the electrical connections and components from damaging environmental influences.

[0040] According to one embodiment, the steering system may further include a steering system support column. The steering system support column may be configured to connect the steering wheel hub and the steering wheel to the vehicle body. The steering system support column may be rigid. The steering system support column may include an eccentric section having a first longitudinal axis that is offset and preferably parallel to the axis of rotation. The steering system support column may include an alignment section having a second longitudinal axis corresponding to the axis of rotation. In other words, corresponding to the axis of rotation may mean that the second longitudinal axis is aligned / coaxial with the axis of rotation.

[0041] The corresponding steering support column provides a new and advantageous structural design which is technically advantageous with regard to space requirements, ergonomic adjustability for the driver and torque generation / transmission with reduced friction and inertia.

[0042] The described combination of the steering system support column design and the steering wheel rotation restriction device contributes to a structurally optimized configuration, in particular with regard to reduced space requirements, robustness and reliability of mechanical end stop integration and simple assembly of the steering system.

[0043] Furthermore, the structure of the steering system support column having the eccentric section and the alignment section and the steering wheel rotation restriction device together allow for optimized integration and attachment of the steering wheel rotation restriction device.

[0044] The steering system support column may be integrally formed, ie formed as a single piece. In particular, the eccentric section may be integrally connected to the alignment section via a connecting portion extending transversely to the first longitudinal axis and the second longitudinal axis.

[0045] The steering system support column's aligned section can be a non-rotatable component to which the stator is attached, while the eccentric section can be another non-rotatable component to which the base of the steering wheel rotation limiting device is attached. Thus, the torque feedback device can be positioned in the area of ​​the steering wheel hub and close to the steering wheel, preferably directly on the hub. This eliminates the need for a reduction gear train and shafts, reducing undesirable friction and inertia. Consequently, system efficiency can be improved.

[0046] In one embodiment, the steering system support column is non-rotatable about its first longitudinal axis but is translationally displaceable along its first longitudinal axis relative to the vehicle body. Thus, the steering system support column can allow the steering system to be adjusted according to the driver's ergonomic needs. The steering system support column can preferably form an inner member of a tubular telescopic arrangement. In this case, the steering system support column is translationally movable relative to the outer member. The steering system support column can be non-rotatable and non-pivotable relative to the outer member. The outer member is capable of connecting the steering system support column to the vehicle body.

[0047] According to one embodiment, the steering wheel hub may be rotatably mounted on the alignment section and may thus at least partially overlap the alignment section in the axial direction.The eccentric section may be axially spaced apart from the steering wheel hub.

[0048] In an embodiment of the steering system, the rotor can be an outer rotor and the stator can be an inner stator. In this case, the rotor can be attached to the inner peripheral surface of the steering wheel hub. The stator can be attached to the outer surface of the steering system support column, more precisely to the outer peripheral surface of the alignment section.

[0049] In one embodiment, the torque feedback device can be configured to increase the torque feedback level when the minimum distance between the sliding element and one of the two end stop surfaces falls below a predetermined threshold. In this case, the rotation of the steering wheel hub / steering wheel can be slowed down to a certain extent before the sliding element fully abuts one of the two end stop surfaces and abruptly prevents further rotation of the steering wheel hub / steering wheel. The threshold value can be defined relative to each of the two end stop surfaces.

[0050] According to one aspect, a steering system for a vehicle comprises a steering wheel hub connected or connectable to a steering wheel, wherein the steering wheel hub and the steering wheel connected or connectable thereby are rotatable about a rotational axis.

[0051] The steering system includes a torque feedback device including an electric motor having a rotor and a stator. The rotor is attached to the steering wheel hub so as to rotate together with the steering wheel hub about a rotation axis, and the stator is fixed to a non-rotatable component of the steering system.

[0052] The steering system comprises a steering system support column comprising an eccentric section having a first longitudinal axis, which is offset and preferably parallel to the axis of rotation, and an alignment section having a second longitudinal axis, which corresponds to the axis of rotation. Corresponding to the axis of rotation may also be described as being aligned or coaxial with the axis of rotation. The steering wheel hub is rotatably mounted on the alignment section and may therefore at least partially overlap the alignment section in the axial direction. More precisely, the steering wheel hub may be rotatably mounted on the outer peripheral surface of the alignment section. The eccentric section is axially spaced apart from the steering wheel hub. The steering system support column may be rigid and may be formed integrally, i.e. as a single piece.

[0053] The steering system includes a steering wheel rotation limiting device for limiting the rotation of the steering wheel hub. In particular, the steering wheel rotation limiting device is configured to at least mechanically limit or prevent the rotation of the steering wheel hub around the rotation axis in two circumferential directions. Therefore, the steering wheel rotation limiting device is configured to mechanically limit or prevent the rotation of the steering wheel connected to the steering wheel hub. The steering wheel rotation limiting device can also allow the steering wheel hub and the steering wheel to rotate more than 360°. The steering wheel rotation limiting device is attached to the eccentric section via the base of the steering wheel rotation limiting device and engages the steering wheel hub via a sliding element. Therefore, the steering wheel rotation limiting device extends axially towards the steering wheel hub, and the sliding element extends radially towards the steering wheel hub. Preferably, the steering wheel rotation limiting device can be attached only to the eccentric section of the steering system support column.

[0054] The corresponding steering support column provides a new and advantageous structural design which is technically advantageous with regard to space requirements, ergonomic adjustability for the driver and torque generation / transmission with reduced friction and inertia.

[0055] The combination of the steering system support column and the steering wheel rotation limiter contributes to a structurally optimized configuration, in particular with regard to reduced space requirements, robustness and reliability of the mechanical end stop integration and simple assembly of the steering system.

[0056] Furthermore, the structure of the steering system support column having the eccentric section and the alignment section and the steering wheel rotation restriction device together allow for optimized integration and attachment of the steering wheel rotation restriction device.

[0057] The eccentric section may be integrally connected to the alignment section via a connecting portion extending transversely to the first and second longitudinal axes.

[0058] The alignment section of the steering system support column can be a non-rotatable component to which the stator is attached. Therefore, the torque feedback device can be arranged in the area of ​​the steering wheel hub and close to the steering wheel, preferably directly on the steering wheel hub. This eliminates the need for a reduction gear train and shafts, reducing undesirable friction and inertia. Consequently, system efficiency can be improved.

[0059] In one embodiment, the steering system support column may be non-rotatable about its first longitudinal axis, but may be translationally displaceable relative to the vehicle body along its first longitudinal axis. Thus, the steering system support column may allow the steering system to be adjusted according to the ergonomic needs of the driver. The steering system support column may preferably form an inner member of a tubular telescopic arrangement, which is axially movably mounted in an outer member of the tubular telescopic arrangement, i.e. translationally movable relative to the outer member. The steering system support column may be configured to be non-rotatable and non-pivotable relative to the outer member. The outer member is capable of connecting the steering system support column to the vehicle body.

[0060] According to one embodiment, the steering system may comprise an electronic control unit for at least controlling the torque feedback device and / or for receiving and transmitting sensor information, in particular from a steering wheel angle sensor of the steering system.

[0061] The electronic control unit can be arranged inside the eccentric section of the steering system support column, thereby effectively utilizing the installation space.

[0062] The base of the steering wheel rotation limiter can cover an opening in an off-axis section of the steering system support column, which provides access to the motor phase connections and / or steering wheel angle sensor connections, which connect the motor and / or at least one sensor to the electronic control unit. The sensor can be a steering wheel angle sensor. Thus, the steering wheel rotation limiter, particularly a detachably attachable one, allows access to the electrical connections for service and maintenance purposes while safely protecting the electrical connections and components from damaging environmental influences.

[0063] The base of the steering wheel rotation limiting device can be attached to the eccentric section of the steering system support column by screws, bolts, rivets or adhesive, or can be welded to the eccentric section of the steering system support column. Attachment by screws or bolts can provide a detachable attachment on the steering system.

[0064] In one embodiment, the rotor can be an outer rotor, and the stator can be an inner stator. In this case, the rotor can be attached to the inner peripheral surface of the steering wheel hub. The stator can be attached to the outer surface of the steering system support column, more precisely connected to the outer peripheral surface of the alignment section. The outer rotor motor of the torque feedback device and its direct arrangement on the steering wheel hub and alignment section eliminate the need for a reduction gear train and shafts, and reduce undesirable friction and inertia. As a result, system efficiency can be improved and installation space requirements can be reduced.

[0065] According to one embodiment, the base of the steering wheel rotation limiting device may comprise two axially opposite end stop surfaces, and the sliding element may be axially slidable relative to the base and the steering wheel hub parallel to the rotation axis between the two opposite end stop surfaces.

[0066] The sliding element may comprise a protrusion, in particular a spiral ridge, which engages a spiral groove formed on the outer peripheral 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 prevents further movement of the sliding element in one direction and thereby prevents further rotation of the steering wheel hub in one direction.

[0067] The base may include 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 transverse to its axially displaceable direction. The compartment only allows axial movement of the sliding element between two opposing end stop surfaces.

[0068] The base may be disposed radially adjacent the steering wheel hub such that the base and an outer peripheral surface of the steering wheel hub completely surround the compartment.

[0069] The steering system can be configured such that, in a state or position in which the sliding element abuts one of the two opposing end stop surfaces, the protrusion remains spaced apart from the two end portions of the helical groove, preferably by a defined distance or a defined segment of the helical groove. Consequently, the rotational restraint of the steering wheel hub is not caused by the interaction of a portion of the protrusion with the end portion of the helical groove, but rather by the abutment of the surface of the sliding element with one of the two end stop surfaces. Consequently, the abutment surface area can be increased compared to known solutions, which prevents damage to the steering system, in particular to the helical groove and the protrusion, even under the influence of strong external forces.

[0070] In one embodiment, the torque feedback device can be configured to increase the torque feedback level when the minimum distance between the sliding element and one of the two end stop surfaces falls below a predetermined threshold. In this case, the rotation of the steering wheel hub / steering wheel can be slowed down to a certain extent before the sliding element fully abuts one of the two end stop surfaces and abruptly prevents further rotation of the steering wheel hub / steering wheel. The threshold value can be defined relative to each of the two end stop surfaces.

[0071] According to one aspect, a steering system for a vehicle comprises a steering wheel hub connected or connectable to a steering wheel, wherein the steering wheel hub and the steering wheel connected or connectable thereby are rotatable about a rotational axis.

[0072] The steering system includes a steering system support column, which includes an eccentric section having a first longitudinal axis, which is offset and preferably parallel to the axis of rotation, and an alignment section having a second longitudinal axis, which corresponds to the axis of rotation. Corresponding to the axis of rotation can also be described as being aligned or coaxial with the axis of rotation. The eccentric section and the alignment section are formed integrally and connected by a connecting portion. The connecting portion is also formed integrally with the eccentric section and the alignment section. Therefore, the eccentric section, the alignment section and the connecting portion are formed as a rigid single-piece component. The steering wheel hub is rotatably mounted on the alignment section and thus at least partially overlaps with the alignment section in the axial direction. The eccentric section is axially spaced apart from the steering wheel hub.

[0073] The steering system includes a torque feedback device including an electric motor having a rotor and a stator. The rotor is fixedly attached to the steering wheel hub so as to be rotatable together with the steering wheel hub about the rotation axis. The stator is non-rotatably fixed to an alignment section of a steering system support column.

[0074] Preferably, the alignment section may form a hub element which is stationary with respect to the rotor and the steering wheel hub and carries the inner stator of the outer rotor electric machine.

[0075] The new and advantageous structural design of an integrally formed, i.e. one-piece, steering system support column comprising an eccentric section and a shaft portion as well as a torque feedback device arranged on the alignment section provides for an optimized use of the installation space while allowing simple adjustability for driver ergonomics and at the same time reducing friction and inertia due to torque generation / transmission.

[0076] Therefore, the described combination of the steering system support column design and the torque feedback device contributes to a structurally optimized configuration.

[0077] A connecting portion, also integrally formed with the eccentric section and the alignment section, may extend transversely to the first and second longitudinal axes.

[0078] The eccentric section, the alignment section and / or the connecting portion may be tubular. In particular, each eccentric section, alignment section and connecting portion may be tubular. The eccentric section, alignment section and connecting portion may at least partially have a substantially rectangular or circular cross-section. Alternatively, the eccentric section, alignment section and / or connecting portion may have any other cross-sectional shape. For example, the eccentric section, alignment section and / or connecting portion may have an elliptical or polygonal cross-section. A polygonal cross-section may be advantageous in view of providing some flat surfaces to provide an angular reference between the axial sliding part and the fixed part of the telescopic arrangement structure so as to prevent rotation relative to each other around the first longitudinal axis. The cross-sectional shapes of the eccentric section, alignment section and connecting portion may be the same or different.

[0079] In one embodiment, the steering support column can be attached to the vehicle body via a vehicle support column. The eccentric section of the steering support column can be mounted in the vehicle support column so as to be movable translationally along its first longitudinal axis, while being non-rotatable and non-pivotable relative to the vehicle support column. This means that in this embodiment, the steering support column and all components supported thereon are respectively movable / immovable relative to the vehicle support column. The steering support column can be attached to the vehicle support column via a bracket, an axial adjustment element, and / or a vertical adjustment element.

[0080] Supporting the eccentric section of the steering support column in the vehicle support column may be achieved at a first end of the steering support column opposite a second end of the steering support column where the torque feedback device is arranged (ie, spaced apart from the alignment section).

[0081] This configuration allows for ergonomic adjustability of the steering system to the driver while eliminating the need for reduction gear trains and shafts, thereby reducing friction and inertia during torque generation and transmission in a steer-by-wire system.

[0082] The steering system support column may form an inner member of the tubular telescopic arrangement and the vehicle support column may form an outer member of the tubular telescopic arrangement. The inner member is axially and translationally mounted in the outer member of the tubular telescopic arrangement.

[0083] The vehicle support column and thus the steering system, i.e., all other system components mounted on / attached to the steering system support column, can be adjusted relative to the vehicle body by being pivotable and / or radially displaceable relative to the vehicle body. The pivotability and / or radial displaceability can involve movement of at least a portion of the steering system support column along at least one transverse axis transverse to the first longitudinal axis.

[0084] According to one embodiment, the steering system support column may include an opening, preferably arranged in the eccentric section or in the connecting portion, which provides access to the motor phase connections and / or the steering wheel angle sensor connections connecting the motor and / or at least one sensor to the electronic control unit. The sensor may be a steering wheel angle sensor. Thus, the steering wheel rotation restriction device, in particular a detachably attached steering wheel rotation restriction device, allows access to the electrical connections for service and maintenance purposes while simultaneously safely protecting the electrical connections and components from damaging environmental influences.

[0085] According to one embodiment, the steering system may include an electronic control unit (ECU) for controlling at least the torque feedback device and / or receiving and transmitting sensor information, such as information from a steering wheel angle sensor. The ECU may be arranged within an off-axis section of the steering system support column, preferably in an area adjacent to or following the connecting portion. In this case, the ECU may be arranged close to the stator windings of the torque feedback motor and / or close to a sensor, such as a rotation angle sensor, for measuring the rotation of the motor's rotor.

[0086] In one embodiment, the steering system may include a plurality of auxiliary components disposed within the alignment section of the steering support column and, therefore, within the stator of the torque feedback motor. The auxiliary components may include an airbag module, a switchgear controller, a driver display arrangement, and / or a wiring harness. By arranging the auxiliary components within the steering support column, installation space may be efficiently utilized, i.e., the total installation space required for the steering system may be reduced.

[0087] In one embodiment, the rotor can be an outer rotor and the stator can be an inner stator. Thus, the torque feedback device can be an outer rotor electric torque feedback machine. In this case, the rotor can be attached to the inner peripheral surface of the steering wheel hub. The stator can be attached to the outer surface of the steering system support column, more precisely connected to the outer peripheral surface of the alignment section. The outer rotor motor of the torque feedback device and its direct arrangement on the steering wheel hub and alignment section eliminate the need for a reduction gear train and shafts, and reduce undesirable friction and inertia. Therefore, the system efficiency can be improved and the installation space requirement can be reduced.

[0088] According to one embodiment, the alignment section of the steering system support column can be provided with a protruding flange portion, which flange portion 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 area between the alignment section and the connecting portion, i.e. the end portion of the alignment section facing away from the steering wheel connected or connectable to the steering system. The protruding flange portion provides a circular annular first bearing surface. By means of the protruding flange portion, the outer diameter of the main part of the alignment section can be minimized while still supporting a steering wheel hub having a substantially larger inner diameter.

[0089] The alignment section of the steering system support column can include an annular portion that provides an annular second bearing surface for a second bearing arrangement arranged between the steering system support column and the steering wheel hub. Preferably, the annular portion can be arranged at least in a region following or adjacent to a steering wheel connected or connectable to the steering system, in other words, at least in a region facing away from the eccentric section and the connecting portion. The annular portion allows the outer shape / contour of the main portion of the alignment section to be freely selected while still rotatably supporting the steering wheel.

[0090] The first bearing device and the second bearing device enable the steering wheel hub and the steering wheel connected thereto to be rotatably supported on the steering system support column.

[0091] In one embodiment, the steering system may include a steering wheel rotation limiting device for at least mechanically limiting rotation of the steering wheel hub in two circumferential directions about the rotation axis. The steering wheel rotation limiting device may be attached to the eccentric section via a base of the steering wheel rotation limiting device and may engage the steering wheel hub via a sliding element.

[0092] The base of the steering wheel rotation limiting device includes two axially opposed end stop surfaces, and a sliding element is axially slidable relative to the base and the steering wheel hub parallel to the rotation axis between the two opposed end stop surfaces. The sliding element may include a protrusion, in particular a spiral ridge, which engages a spiral groove formed on the outer peripheral 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 prevents further movement of the sliding element and thus prevents further rotation of the steering wheel hub.

[0093] The base of the steering wheel rotation limiting device can overlap with the protruding flange portion in the axial direction relative to the rotation axis, thereby overlapping with the first bearing surface. Therefore, an advantageous compact design of the steering system structure can be achieved.

[0094] According to one aspect, a steering system for a vehicle includes a steering wheel and a steering wheel hub, wherein the steering wheel is mechanically attached to the steering wheel hub via a fixing element. Preferably, the steering wheel is directly and fixedly attached to the steering wheel hub. The fixing element may be a bolt and / or a screw. Preferably, a total of three to ten screws may be arranged at equal distances around the rotation axis of the steering wheel and the steering wheel hub.

[0095] The steering system includes a steering system support column, wherein the steering wheel hub is rotatably mounted on the steering system support column such that the steering wheel and the steering wheel hub are rotatable about a rotational axis.

[0096] The steering system includes a torque feedback device comprising an electric motor having an outer rotor and an inner stator with stator windings. The outer rotor is attached to a steering wheel hub for rotation therewith about a rotation axis. Preferably, the outer rotor is fixed to an inner peripheral surface of the steering wheel hub. The inner stator is non-rotatably fixed to a steering system support column. Preferably, the inner stator is fixed to an outer peripheral surface of the steering system support column.

[0097] The fixing element is arranged at a different radial position relative to the rotation axis than the stator winding. In other words, when viewed relative to the rotation axis, the fixing element is arranged at a different radial height than the stator winding, i.e. the fixing element has a different radial distance from the rotation axis than the stator winding.

[0098] Providing an outer rotor motor for the torque feedback device and arranging the fixed element in a radial position different from the stator windings allows for an advantageously compact design of the steer-by-wire steering system, which reduces the required installation space.

[0099] A portion of the fixed element can axially overlap a portion of the stator winding relative to the rotation axis. In particular, a portion of each fixed element, or only a portion of one or a specific fixed element, can axially overlap a portion of the stator winding relative to the rotation axis. This arrangement is possible by arranging the fixed element at a different radial position than the stator winding. Consequently, at least a portion of the fixed element can be arranged parallel to the stator winding, further contributing to a compact design of the steering system.

[0100] According to one embodiment, the steering system may include a first bearing arrangement disposed between a steering system support column and a steering wheel hub for enabling the steering wheel hub to rotate relative to the steering system support column. The steering system may include a second bearing arrangement disposed between the steering system support column and the steering wheel hub for enabling the steering wheel hub to rotate relative to the steering system support column. The second bearing arrangement may be axially spaced from the first bearing arrangement relative to the axis of rotation. The second bearing arrangement may be closer to the steering wheel than the first bearing arrangement.

[0101] The first bearing arrangement can be arranged at a different radial position relative to the rotation axis than the second bearing arrangement. Similarly, the term "at a different radial position" when viewed with respect to the rotation axis can also be described as being at a different radial height, i.e., at a different radial distance from the rotation axis. Arranging the second bearing arrangement at a different radial position than the first bearing arrangement, i.e., closer to the rotation axis, allows for an overlapping arrangement of further components parallel to the second bearing arrangement, further contributing to a compact design.

[0102] The fixing elements may be arranged at a different radial position relative to the rotation axis than the first bearing arrangement; and / or the fixing elements may be arranged at a different radial position relative to the second bearing arrangement. Such an arrangement also enables an overlapping / parallel arrangement of components of the steering system, which further contributes to a compact design of the steering system and reduced installation space requirements.

[0103] In one embodiment, a steering support column, particularly an alignment section of the steering support column, can be provided with an outwardly protruding flange portion that provides a circular, annular first bearing surface for the first bearing arrangement. The protruding flange portion, which protrudes from the outer peripheral surface of the steering support column, is preferably arranged in a transition region between the alignment section and a connecting portion of the steering support column. The protruding flange portion minimizes the outer diameter of the main portion of the alignment section while still supporting a steering wheel hub having a substantially larger inner diameter.

[0104] The steering system support column, in particular the alignment section of the steering system support column, can be equipped with a ring-shaped portion, which provides a ring-shaped second bearing surface for the second bearing device. The ring-shaped portion providing the second bearing surface can have a much smaller outer diameter than the protruding flange portion. The ring-shaped portion can be arranged at least in the area behind or adjacent to the steering wheel, that is, at least in the area facing away from the eccentric section. The ring-shaped portion allows the outer shape / contour of the main part of the alignment section to be freely selected while still rotatably supporting the steering wheel.

[0105] In one embodiment, the fixing elements may overlap axially with the second bearing arrangement relative to the axis of rotation. The fixing elements may partially or completely overlap the second bearing arrangement. This further contributes to a compact design of the steering system and reduced installation space requirements.

[0106] The steering wheel hub may be provided with an inwardly projecting flange portion, which provides an opposing bearing surface for the second bearing arrangement, the opposing bearing surface being substantially opposite the second bearing surface. Inwardly projecting means that the inwardly projecting flange portion projects toward the steering system support column, i.e., toward the axis of rotation. The opposing bearing surface forms an annular portion for supporting the second bearing arrangement.

[0107] The inwardly protruding flange portion of the steering wheel hub may be formed in an area of ​​the steering wheel hub that is axially arranged between the steering wheel and the motor of the torque feedback device. Thus, the motor may be covered toward the steering wheel by the inwardly protruding flange portion.

[0108] A blind hole can be formed in the region of the protruding flange portion of the steering wheel, preferably in the inwardly protruding flange portion, wherein a fixing element extends into the blind hole for fastening the steering wheel to the steering wheel hub. The blind hole can be provided with an internal thread in order to fasten a fixing element in the form of a screw or bolt therein.

[0109] In one embodiment, the fixing elements may be arranged at substantially the same radial position relative to the rotation axis as the outer rotor of the torque feedback device.Such a configuration may limit the radial extension of the steering system in the region of the torque feedback device.

[0110] According to one embodiment, the steering wheel may comprise a rigid steering wheel skeleton comprising a through hole, wherein the fixing element extends through the through hole into the steering wheel hub for fastening the steering wheel to the steering wheel hub. Preferably, the through hole may be aligned with a blind hole in the steering wheel hub.

[0111] According to one embodiment, the steering system support column may include an eccentric section having a first longitudinal axis, which is offset and preferably parallel to the axis of rotation, and the steering system support column may include an alignment section having a second longitudinal axis, which corresponds to the axis of rotation. The eccentric section and the alignment section may be formed integrally and connected by a connecting portion. The steering wheel hub may be rotatably mounted on the alignment section and therefore at least partially overlap with the alignment section in the axial direction, while the eccentric section is axially spaced apart from the steering wheel hub. The stator may be non-rotatably fixed to the alignment section of the steering system support column.

[0112] In one embodiment, the steering system may include a steering wheel rotation limiting device for limiting the rotation of the steering wheel hub. In particular, the steering wheel rotation limiting device may be configured to at least mechanically limit or prevent the rotation of the steering wheel hub in two circumferential directions around the axis of rotation. Therefore, the steering wheel rotation limiting device may be configured to mechanically limit or prevent the rotation of the steering wheel connected to the steering wheel hub. The steering wheel rotation limiting device may also allow the steering wheel hub and the steering wheel to rotate more than 360°. The steering wheel rotation limiting device may be attached to the eccentric section via the base of the steering wheel rotation limiting device and may engage the steering wheel hub via a sliding element. Therefore, the steering wheel rotation limiting device may extend axially toward the steering wheel hub and the sliding element may extend radially toward the steering wheel hub. Preferably, the steering wheel rotation limiting device may be attached only to the eccentric section of the steering system support column.

[0113] Although some features, functions, embodiments, technical effects and advantages have been described with respect to one aspect, it should be understood that these features, functions, embodiments, technical effects and advantages can be combined with each other and applied to other embodiments and aspects. BRIEF DESCRIPTION OF THE DRAWINGS

[0114] For a better understanding of embodiments of the invention and to show how the same may be practiced, reference will now be made, by way of example only, to the accompanying drawings in which like reference numerals refer to corresponding elements or sections throughout.

[0115] In the attached figure:

[0116] Figure 1 A schematic cross-sectional view of a steering system according to an embodiment of the present invention is shown.

[0117] Figure 2 Shown Figure 1 Schematic side view of the steering system.

[0118] Figure 3 Shown Figure 1 Schematic perspective view of a steering system.

[0119] Figure 4 Shown Figure 1 Another schematic perspective view of a steering system.

[0120] Figure 5 Shown Figure 1 Another schematic perspective view of a steering system.

[0121] Figure 6 Shown Figure 1 Another schematic perspective view of a steering system.

[0122] Figure 7A to 7C show a steering wheel rotation limiting device of a steering system in schematic exploded, assembled and installed states.

[0123] Figure 8 8A to 8F show schematic diagrams of a steering wheel rotation limiting device for illustrating the functional principle of the steering wheel rotation limiting device.

[0124] Figure 9 A to 9C show schematic diagrams of a steering wheel rotation limiting device and a steering wheel hub for illustrating the functional principle of the steering wheel rotation limiting device. DETAILED DESCRIPTION

[0125] Various examples of embodiments of the present invention will be explained in more detail with the aid of the following embodiments which are illustrated in the drawings and / or described below.

[0126] Figures 1 to 6 FIG. 1 shows a schematic diagram of a steering system 10 for a road vehicle according to an embodiment of the present invention. Figures 1 to 6 As shown, the steering system 10 is a steer-by-wire type steering system that has no direct mechanical connection for transmitting the driver's steering commands from the steering wheel 12 of the steering system 10 to the vehicle's wheels (not shown). Instead, the mechanical connection is replaced by an electromechanical arrangement.

[0127] In addition to the steering wheel 12, the steering system 10 also includes a steering wheel hub 14 that is mechanically connected to the steering wheel 12. The steering wheel hub 14 and the steering wheel 12 are non-rotatable relative to each other, but are rotatable together about an axis of rotation A. The steering wheel 12 is non-rotatably detachably attached to the steering wheel hub 14 by means of a fixing element 16 in the form of a screw. More precisely, the steering wheel 12 is provided with an internal armature 18, wherein the fixing element 16 extends through a through-hole 20 in the internal armature 18 into an internally threaded blind hole 22 provided in the steering wheel hub 14.

[0128] The steering wheel hub 14 is rotatably supported on a rigid steering support column 24 of the steering system 10, and more precisely, on an alignment section 26 of the steering support column 24. In addition to the alignment section 26, the steering support column 24 includes an eccentric section 28 that is integrally formed with the alignment section 26. The eccentric section 28 is axially spaced from the alignment section 26 and the steering wheel hub 14, while the steering wheel hub 14 overlaps the alignment section 26 and is coaxially positioned with the alignment section 26. The eccentric section 28 has a first longitudinal axis L1 that is offset and parallel to the axis of rotation A. The alignment section 26 has a second longitudinal axis L2. The alignment section 26 of the steering support column 24 is aligned or coaxial with the steering wheel hub 14 and the steering wheel 12, i.e., the second longitudinal axis L2 corresponds to the axis of rotation A.

[0129] The eccentric section 28 and the alignment section 26 are integrally formed and connected by a connecting portion 30 that extends transversely to the first and second longitudinal axes L1 and L2.

[0130] The steering wheel hub 14 is rotatably mounted on the alignment 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 may be ball bearings or roller bearings.

[0131] The first bearing device 32 is supported on a protruding flange portion 36 of the alignment section 26 of the steering system support column 24, which protrudes radially outward from the outer peripheral surface of the alignment section 26. The protruding flange portion 36 provides a circular annular first bearing surface for supporting the first bearing device 32. The protruding flange portion 36 is arranged in the vicinity of the connecting portion 30, that is, in the transition region between the alignment section 26 and the connecting portion 30. Therefore, the first bearing device 32 is axially located at a first end portion of the alignment section 26 facing the connecting portion 30.

[0132] The second bearing device 34 is supported on an annular portion 38 of the alignment section 26 of the steering system support column 24. The annular portion 38 is formed in an area along the alignment section 26 of the steering wheel 12 and extends toward the protruding flange portion 36. The annular portion 38 provides a second bearing surface for the second bearing device 34. Therefore, the second bearing device 34 is axially located at a second end portion of the alignment section 26 opposite the first end portion.

[0133] The first bearing device 32 is mounted between the protruding flange portion 36 of the alignment section 26 and the steering wheel hub 14 via a support bushing 40 provided between the first bearing device 32 and the inner peripheral surface of the steering wheel hub 14 .

[0134] The second bearing device 34 is mounted directly between the annular portion 38 of the alignment section 26 and the steering wheel hub 14. To this end, the steering wheel hub 14 is provided with an inwardly protruding flange portion 42, which provides a counter bearing surface for the second bearing device 34. At the same time, the inwardly protruding flange portion 42 covers the components located inside the steering wheel hub 14. Figure 1 As shown, the blind hole 22 for receiving the fixing element 16 extends into or through the inwardly projecting flange portion 42 .

[0135] The steering system 10 also includes a torque feedback device 44 comprising an electric motor having a rotor 46 and a stator 48 with stator windings 50. The torque feedback device 44 is operable to generate a resistive torque to the rotation of the steering wheel 12, thereby simulating the resistive torque present in conventional steering systems. In other words, the torque generated by the torque feedback device 44 can counteract the rotational force applied to the steering wheel 12 by the driver.

[0136] In the illustrated embodiment, the motor is an outer rotor motor that includes an outer rotor 46 and an inner stator 48. The rotor 46 is fixed to the inner peripheral surface of the steering wheel hub 14. Thus, the rotor 46 can rotate with the steering wheel hub 14 about the rotation axis A. The rotor 46 is non-rotatable relative to the steering wheel hub 14. The stator 48 is fixed to the rotationally stationary (i.e., non-rotatable) alignment section 26 of the steering system support column 24. Thus, the steering wheel hub 14 and the rotor 46 can rotate together about the stator 48 and the alignment section 26.

[0137] The motor of the torque feedback device 44 is arranged within the steering wheel hub 14. The torque feedback device 44 is radially surrounded and thus covered by the steering wheel hub 14 (the inner peripheral surface of the steering wheel hub 14) and the alignment section 26 of the steering system support column 24 (the outer peripheral surface of the alignment section 26). The torque feedback device 44 is axially located between the protruding flange portion 36 of the alignment section 26 and the annular portion 38 of the alignment section 26. The torque feedback device 44 is axially surrounded and thus covered on one side by the protruding flange portion 36 of the alignment section 26, the first bearing device 32, and the support bushing 40, and on the other side by the inwardly protruding flange portion 42 of the steering wheel hub 14 and the second bearing device 34.

[0138] The arrangement, configuration and support of the steering wheel hub 14, steering wheel 12, torque feedback device 44 and steering system support column 24 provide a very compact structure. More specifically, as Figure 1 As shown, the various components are arranged at least partially parallel to one another with respect to their radial and / or axial arrangement.

[0139] That is, the fixing element 16 is arranged at a different radial position, i.e., a different radial height, than the stator winding 50 relative to the rotation axis A. Therefore, the fixing element 16 and the blind hole 22 at least partially overlap the stator winding 50 in the axial direction. The stator winding 50 can be arranged closer to the rotation axis A than the fixing element 16.

[0140] Furthermore, the second bearing device 34 is arranged at a different radial position, i.e., a different radial height, relative to the rotation axis A than the stator winding 50, and is also arranged at a different radial position, i.e., a different radial height, than the fixed element 16. In the illustrated embodiment, the fixed element 16 overlaps the second bearing device 34 in the axial direction. The second bearing device 34 may be arranged closer to the rotation axis A than the stator winding 50 and may be arranged closer to the rotation axis A than the fixed element 16.

[0141] Furthermore, the first bearing device 32 is arranged at a different radial position, i.e., at a different radial height, than the second bearing device 34 relative to the rotation axis A, and is arranged at a different radial position, i.e., at a different radial height, than the fixed element 16. The first bearing device 32 is arranged at a similar radial position as the starting winding 50 relative to the rotation axis A. The first bearing device 32 may be arranged closer to the rotation axis A than the stator fixed element 16, and may be arranged farther from the rotation axis A than the second bearing device 34.

[0142] The fixing element 16 is arranged at a similar radial position to the outer rotor 46 of the torque feedback device 44 relative to the axis of rotation A. This limits the radial extension of the steering system 10 in the region of the torque feedback device 44 .

[0143] The steering system 10 further includes a steering wheel rotation limiting device 52 for limiting the 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 from the steering wheel hub 14, more precisely adjacent to the outer peripheral 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.

[0144] The steering wheel rotation limiting device 52 includes a base 54 and a sliding element 56 disposed in a compartment 58 formed in the base 54. The sliding element 56 is axially slidable relative to the base 54 and the steering wheel hub 14. The sliding element 56 is axially slidable relative to the base 54 and the steering wheel hub 14. The sliding element 56 is axially slidable relative to the two opposing end stop surfaces 60, 62 (see FIG. Figure 7 A to 9C). The sliding element 56 includes a protrusion 64 that engages a helical groove 66 formed on the outer peripheral surface of the steering wheel hub 14. Through the interaction of the protrusion 64 and the helical groove 66, rotation of the steering wheel hub 14 causes axial movement of the sliding element 56. Similarly, abutment of the sliding element 56 with one of the two end stop surfaces 60, 62 prevents further movement of the sliding element 56 in a certain direction, thereby preventing further rotation of the steering wheel hub 14 in a certain rotational direction. Therefore, the steering wheel rotation limiting device 52 is configured to restrict rotation of the steering wheel hub 14 and the steering wheel 12 connected thereto.

[0145] The base 54 of the steering wheel rotation limiting device 52 is fixed to the eccentric section 28 of the steering system support column 24 by screws 68 (see Figures 5 to 9 C). The steering wheel rotation limiting device 52, and more specifically the base 54, extends axially from the eccentric section 28 of the steering system support column 24 to the steering wheel hub 14 such that the compartment 58 is disposed between and surrounded by the base 54 and the outer peripheral surface of the steering wheel hub 14.

[0146] Will be in Figure 7 The function and further details of the steering wheel rotation limiting device 52 are described in the context of FIG9A to FIG9C.

[0147] The base 54 of the steering wheel rotation limiting device 52 covers an opening 70 disposed in the eccentric section 28 of the steering system support column 24. More specifically, the opening 70 is arranged in another transition area between the eccentric section 28 and the connecting portion 30. For servicing and maintenance purposes, the opening 70 provides access to a motor phase connection 72 and an electric steering wheel angle sensor connection 74. The motor phase connection 72 connects the motor of the torque feedback device 44 to a control unit / control electronics 76. The electric steering wheel angle sensor connection 74 connects a steering wheel angle sensor 78 to the control unit / control electronics 76.

[0148] The control unit 76 is arranged within the hollow tubular eccentric section 28 of the steering system support column 24. More precisely, the control unit 76 is arranged in a portion of the eccentric section 28 close to the connecting portion 30 so as to position the control unit 76 and the motor close to each other.

[0149] The steering wheel angle sensor 78 is configured to measure the current steering angle and thus detect the driver's steering command, which is electronically transmitted to the actuator for actuating / steering the wheels according to the command. The steering wheel angle sensor 78 is arranged adjacent to or transverse to the first bearing arrangement 32.

[0150] The steering system support column 24 forms the inner member of the tubular telescoping arrangement 80. The outer member of the tubular telescoping arrangement 80 is realized by the vehicle support column 82. In particular, the eccentric section 28 is axially slidably mounted within the outer member / vehicle support column 82 of the tubular telescoping arrangement 80. Thus, the steering system support column 24 is translationally movable relative to the vehicle support column 82 and relative to the vehicle body, but is not rotatable or pivotable relative to the vehicle support column 82.

[0151] The steering support column 24 is connected to the vehicle body (not shown) via a vehicle support column 82 via a bracket, an axial adjustment element, and a vertical adjustment element 84. Therefore, the steering support column 24 and all components supported thereon are only translationally displaceable relative to the first longitudinal axis L1, independent of the vehicle support column 82. Furthermore, the steering support column 24 and all components supported thereon are radially displaceable / pivotable relative to the vehicle body, i.e., the adjustability / displaceability of the vehicle support column 82.

[0152] The steering support column 24 has a hollow tubular shape. The steering support column 24 is formed as a rigid single-piece component and is preferably made of metal. Figures 3 to 6 As can be seen in Figures 3 to 6 Different perspective views of the steering system 10 are shown, with at least the eccentric section 28 of the steering system support column 24 having a substantially rectangular cross-section. Such a shape is particularly advantageous for accommodating and attaching the control unit 76. Similar to the eccentric section 28, the vehicle support column 82, which together with the eccentric section 28 forms the tubular telescoping arrangement 80, has a generally rectangular cross-section.

[0153] The connecting portion 30 of the steering system support column 24 forms a tapered transition that tapers from the eccentric section 28 to the alignment section 26. The alignment section 26 has a smaller diameter than the eccentric section 28. The alignment section 26 has a substantially circular cross-section.

[0154] If combined Figure 1 exist Figure 3 and Figure 5 As can also be seen in FIG, the steering wheel 12 is provided with an interior space 86 for accommodating auxiliary components (not shown), such as an air bag module, a switchgear controller, a driver display arrangement, etc. These auxiliary components, as well as additional auxiliary components, such as wiring harnesses, can extend into the hollow tubular alignment section 26. The auxiliary components, as well as additional auxiliary components, can thus be arranged within and / or attached to the interior of the alignment section 26 of the steering system support column 24.

[0155] Figure 7 A to 9C are used to disclose details about the function and configuration of the steering wheel rotation limiting device 52. Figure 7 A shows the components of the steering wheel rotation limiting device 52, that is, an exploded view. Figure 7 B shows the components of the steering wheel rotation limiting device 52 in an assembled state. Figure 7 C shows a steering wheel rotation limiting device 52 mounted to or interacting with the steering wheel hub 14 .

[0156] like Figure 7As shown in FIG. 7A to FIG. 7C , four screws 68 extend through the base 54 to securely secure the steering wheel rotation limiting device 52 to the steering system support column 24. The base 54 has a compartment 58 formed therein. Two axially opposed side surfaces of the compartment 58 constitute end stop surfaces 60, 62. The compartment 58 is formed to partially complement the sliding element 56 that can be arranged therein (see FIG. 7B ). Figure 7 B). Thus, compartment 58, or more precisely, the bottom and sides of compartment 58, constrain the movability of sliding element 56 to axial slidability between two end stop surfaces 60, 62 (indicated by arrow AS). The two end stop surfaces 60, 62 limit the slidability of sliding element 56 in the axial direction. When sliding element 56 abuts one of the two end stop surfaces 60, 62, further movement in the current direction is prevented, and sliding element 56 can only move in the opposite axial direction, i.e., toward the corresponding opposing end stop surface 60, 62. In the installed state, the surface facing the steering wheel hub 14 is curved and substantially complementary to a corresponding portion of the outer peripheral surface of the steering wheel hub 14.

[0157] The sliding element 56 engages a helical groove 66 formed in the outer peripheral surface of the steering wheel hub 14 via a protrusion 64. The protrusion 64 is formed as a helical ridge adapted to the shape and size of the helical groove 66. The sliding element 56 interacts with the steering wheel hub 14 via the helical groove 66. When the steering wheel 12, and thus the steering wheel hub 14, rotates, the sliding element 56 is dragged axially within the compartment 58 according to one of the arrows AS. The sliding element 56 slides until it is stopped by the rotation of the steering wheel hub 14 or until further movement is blocked by the sliding element 56 contacting one of the two end stop surfaces 60, 62. Thus, the blocking of further axial movement of the sliding element 56 blocks further rotation of the steering wheel hub 14, and thus further rotation of the steering wheel 12 in the rotational direction, which would result in further axial movement of the sliding element 56 toward the now blocked end stop surface 60, 62.

[0158] like Figure 7As shown in FIG. 1A , the sliding element 56 has an axial width W. The axial width W of the sliding element 56 determines the free space within the compartment 58 between the sliding element 56 and the end stop surfaces 60 , 62 . Therefore, by adjusting or selecting the axial width W of the sliding element 56 , the maximum travel distance of the sliding element 56 between the two end stop surfaces 60 , 62 , i.e., the maximum axial mobility, is adjustable. Thus, by simply replacing the sliding element 56 and adjusting its axial width W and the size and geometry of the protrusion 64 , the steering wheel rotation limiting device 56 can be flexibly used for different vehicle configurations. In particular, the axial width W can be selected based on one or more of the following parameters: the length of the helical groove 66 , the pitch of the helical groove 66 , the distance between the two opposing end stop surfaces 60 , 62 , and the circumferential length of the steering wheel hub 14 .

[0159] exist Figure 8 A, 8B and 9A show the sliding element 56 in abutment with the end stop surface 60. In this position, the sliding element 56 can only slide in a direction toward the opposite end stop surface 62. That is, in this position, the steering wheel hub 14 and the steering wheel 12 can only be rotated in one particular rotational direction, which causes the sliding element 56 to move toward the opposite end stop surface 62. Figure 8 C, 8D and 9B show the position in which the sliding element 56 can slide freely in both axial directions. That is, in this position, the steering wheel hub 14 and the steering wheel 12 can rotate freely in both rotational directions. Figure 8 E, 8F, and 9C illustrate the abutment of the sliding element 56 with the opposing end stop surface 62. In this position, the sliding element 56 can only slide in a direction toward the end stop surface 60. That is, in this position, the steering wheel hub 14 and the steering wheel 12 can only be rotated in one particular rotational direction, which causes the sliding element 56 to move toward the end stop surface 60.

[0160] At least Figure 9 As can be seen in FIG. 5A , in the position where the sliding element abuts one of the two opposing end stop surfaces, the protrusion 64 remains spaced apart from the proximal end portion 88 of the helical groove 66. Thus, the rotational restraint of the steering wheel hub 14 is not caused by the abutment of the protrusion 64 with the end portion 88 of the helical groove 66, but rather by the abutment of the sliding element 56 with one of the two end stop surfaces 60, 62. This robust configuration prevents damage to the steering system 10, and in particular damage to the helical groove 66 and the protrusion 64, even under the influence of strong external forces.

[0161] Reference Symbol List

[0162]

Claims

1. A steering system (10) for a vehicle, comprising: A steering wheel hub (14) connected to the steering wheel (12) or connectable to the steering wheel, the steering wheel hub (14) being rotatable about a rotation axis (A); a torque feedback device (44) comprising an electric motor having a rotor (46) and a stator (48), the rotor (46) being attached to the steering wheel hub (14) so ​​as to be rotatable together with the steering wheel hub (14) about the rotation axis (A), and the stator (48) being fixed to a non-rotatable component (26) of the steering system (10); and A steering wheel rotation limiting device (52) for limiting the rotation of the steering wheel hub (14); Characterized in that the rotor (46) is an outer rotor and the stator (48) is an inner stator, and the steering wheel rotation limiting device (52) is arranged radially offset from the steering wheel hub (14) and comprises: a base (54) fixed to the non-rotatable component (26) of the steering system (10) or to another non-rotatable component, the base (54) comprising two opposing end stop surfaces (60, 62), a sliding element (56) axially slidable relative to the base (54) and relative to the steering wheel hub (14) between the two opposite end stop surfaces (60, 62) parallel to the axis of rotation, The sliding element (56) includes a protrusion (64) that engages a spiral groove (66) formed on the peripheral surface of the steering wheel hub (14) so ​​that rotation of the steering wheel hub (14) causes axial movement of the sliding element (56) and abutment of the sliding element (56) with one of two end stop surfaces (60, 62) prevents movement of the sliding element (56) and rotation of the steering wheel hub (14).

2. The steering system (10) according to claim 1, wherein: The base (54) includes a compartment (58) formed therein that accommodates the sliding element (56) and thereby inhibits radial movement of the sliding element (56) in a direction away from the steering wheel hub (14) and inhibits lateral movement of the sliding element (56) transverse to its axial movement (AS).

3. The steering system (10) according to claim 2, wherein: The base (54) is arranged radially adjacent to the steering wheel hub (14) such that the base (54) and the outer peripheral surface of the steering wheel hub (14) completely surround the compartment (58).

4. The steering system (10) according to claim 1, wherein: In a condition in which the sliding element (56) abuts one of the two opposing end stop surfaces (60, 62), the projection (64) remains spaced apart from the end portion (88) of the helical groove (66).

5. The steering system (10) according to claim 1, in, At least one of the following conditions exists: (i) the sliding element (56) has a substantially rectangular cross-section, and (ii) The protrusion (64) is a spiral ridge.

6. The steering system (10) according to claim 1, wherein: The axial width (W) of the sliding element (56) is adapted according to one or more of the following parameters: the length of the helical groove (66), the pitch of the helical groove (66), the distance between two opposing end stop surfaces (60, 62) and the circumferential length of the steering wheel hub (14).

7. The steering system (10) according to claim 1, wherein: The steering wheel rotation limiting device (52) is attached to the non-rotatable component or the other non-rotatable component (28) of the steering system (10) by screws (68), bolts, rivets or adhesive, or is welded to the non-rotatable component or the other non-rotatable component (28) of the steering system (10).

8. The steering system (10) according to claim 1, wherein: The base (54) of the steering wheel rotation limiting device (52) covers an opening (70) in the non-rotatable component or another non-rotatable component (28), the opening providing access to electrical connections (72, 74) connecting the motor and / or at least one sensor (78) to an electronic control unit (76).

9. The steering system (10) of claim 1 further comprising a steering system support column (24), the steering system support column comprising an eccentric section (28) having a first longitudinal axis (L1) and comprising an alignment section (26) having a second longitudinal axis (L2), the first longitudinal axis being offset and parallel to the rotation axis (A), the second longitudinal axis corresponding to the rotation axis (A).

10. The steering system (10) according to claim 9, wherein: The eccentric section (28) is integrally connected to the alignment section (26) via a connecting portion (30), which extends transversely to the first longitudinal axis (L1) and the second longitudinal axis (L2).

11. The steering system (10) according to claim 9, wherein: The alignment section (26) of the steering system support column (24) is a non-rotatable component to which the stator (48) is attached, and the eccentric section (28) is another non-rotatable component to which the base (54) of the steering wheel rotation limiter (52) is attached.

12. The steering system (10) according to claim 9, wherein: The steering system support column (24) is non-rotatable but translationally displaceable along its first longitudinal axis (L1), wherein the steering system support column (24) forms an inner component of the tubular telescopic arrangement (80).

13. The steering system (10) according to claim 9, wherein: The steering wheel hub (14) is rotatably mounted on the alignment section (26), while the eccentric section (28) is axially spaced from the steering wheel hub (14).

14. The steering system (10) according to claim 1, It is characterized by: The steering wheel hub (14) is arranged between a steering system support column (24) of the steering system (10) and the steering wheel hub (14), and is used to enable the steering wheel hub (14) to rotate relative to the steering system support column (24); The steering system support column (24) is provided with an outwardly protruding flange portion (36), and the flange portion provides an annular first bearing surface for the first bearing device (32); wherein the base (54) of the steering wheel rotation limiting device (52) overlaps the protruding flange portion (36) in an axial direction relative to the rotation axis (A), and thus overlaps the first bearing surface.

15. The steering system (10) of claim 1, wherein: The torque feedback device (44) is configured to increase the torque feedback level when a minimum distance between the sliding element (56) and one of the two end stop surfaces (60, 62) falls below a predetermined threshold.

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