Steer-by-wire steering system with steering wheel rotation limiting device

Abstract

The present disclosure relates to a steering system (10) including a steering wheel rotation limiting device (52) arranged radially offset relative to a steering wheel hub (14), the steering wheel rotation limiting device (52) including a base (54) fixed to the above or another non-rotatable component (26) of the steering system (10). The base (54) includes two opposing dead-end surfaces (60, 62), and the steering wheel rotation limiting device (52) includes a sliding element (56) axially slidable relative to the base (54) and relative to the steering wheel hub (14) parallel to the axis of rotation between the two opposing dead-end surfaces (60, 62). The sliding element (56) has a protrusion (64) that engages a helical groove (66) formed in the circumferential 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 dead end surfaces (60, 62) prevents movement of the sliding element (56) and rotation of the steering wheel hub (14).

Description

[Technical Field]

[0001] The present invention relates to a steer-by-wire steering system for a vehicle, particularly an automotive vehicle, that is equipped with a steering wheel rotation limiting device. [Background technology]

[0002] There is growing interest in and use of drive-by-wire systems in the automotive and trucking industry, where mechanical components are replaced by electromechanical configurations. The move toward fully electric and autonomous vehicles is driving further development of drive-by-wire steering systems and increasing the need for innovative concepts.

[0003] One specific subcategory of drive-by-wire systems relates to steer-by-wire steering systems that aim to replace traditional mechanical components that transmit a driver's steering commands from the steering wheel to the wheels with an electro-mechanical arrangement. Such electro-mechanical steer-by-wire arrangements can partially or completely eliminate the need for a direct or indirect mechanical connection between the steering wheel and the drive wheels. Instead of using mechanical transmission, the steering command is detected by a sensor array and sent in the form of a control signal via a control unit to an electro-mechanical actuator that is configured to execute the steering command.

[0004] Steer-by-wire configurations open up completely new possibilities regarding installation space, steering system assembly, safety and design concepts.

[0005] A steer-by-wire steering system is known, for example, from U.S. Patent Application Publication No. 2020 / 0070871, which discloses a vehicle steering wheel assembly including a steering wheel, a control component, a rotation measurement component for measuring a rotation state of the steering wheel, and a road sense simulator for applying a resisting torque to a rotation of the steering wheel according to the rotation state of the steering wheel. A steering column is disposed below the steering wheel, an upper end of the steering column is connected to the steering wheel, and a lower end of the steering column is connected to the road sense simulator. The road sense simulator is fixed to a body of the vehicle. Both the rotation measurement component and the load sense simulator are connected to the control component, and the control component controls the road sense simulator to apply a resisting torque to a rotation of the steering wheel according to measurement data of the rotation measurement component.

[0006] Furthermore, Patent Document 2 (JP 2019-214360 A) discloses a steer-by-wire power steering device equipped with a special operating range limit regulation device to replace a given mechanical end stop present in a conventional steering system.

[0007] Prior art steer-by-wire systems often have complex structures and are limited in terms of their functionality and applicability and adaptability to various vehicle requirements. [Prior art documents] [Patent documents]

[0008] [Patent Document 1] US Patent Application Publication No. 2020 / 0070871 [Patent Document 2] Japanese Patent Application Publication No. 2019-214360 Summary of the Invention [Problem to be solved by the invention]

[0009] It is an object of the present invention to provide a steering system having improved characteristics and which overcomes at least some of the disadvantages of the prior art.

[0010] It is an object of the present invention to provide a robust and reliable solution for limiting the maximum rotation angle, especially in steer-by-wire steering systems. [Means for solving the problem]

[0011] These objects are achieved by the subject matter of the independent claims. Preferred embodiments and advantageous features are set out in the dependent claims and the following description.

[0012] The present invention relates to a steering system for a vehicle, more precisely to a steer-by-wire steering system.

[0013] The steering system includes a steering wheel hub connected or connectable to the steering wheel. The steering wheel hub is rotatable about a rotation axis. Thus, when the steering wheel is connected to the hub, the steering wheel is rotatable about the rotation axis together with the steering wheel hub. In particular, the steering wheel hub can be rotatably mounted on a steering system support column.

[0014] The steering system may comprise a steering handle, which preferably comprises a grip portion.

[0015] The steering wheel can be mechanically attached directly or indirectly to the steering wheel hub by a fastening element, which can be, for example, a bolt, screw, rivet, nut, adhesive, and / or swaged (pressed and / or deformed).

[0016] The steering system can include a torque feedback device including an electric machine having a rotor and a stator with stator windings, the rotor fixedly attached to the steering wheel hub so as to be rotatable therewith about a rotation axis, and the stator 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 can be operated to generate a resistive torque to rotation of the steering wheel to simulate the resistive torque present in a conventional steering system.

[0017] The rotor may be an outer rotor and the stator may be an inner stator.

[0018] With respect to the axis of rotation, the fixed elements may be arranged at a different radial position or height than the stator windings.

[0019] The steering system may include a rigid steering system support column including an off-axis section having a first longitudinal axis offset from, and preferably parallel to, the rotation axis, and an alignment section having a second longitudinal axis coincident with the rotation axis. Coincident with the rotation axis may also be referred to as being aligned or coaxial with the rotation axis. The steering wheel hub may be rotatably mounted on the alignment section such that it at least partially overlaps the alignment section in the axial direction. The off-axis section may be axially spaced or displaced from the steering wheel hub.

[0020] The off-axis and aligned sections may be integrally formed and connected by a connecting portion, which is also a rigid portion formed integrally or in one piece with the off-axis and aligned sections.

[0021] The steering system may include a steering wheel rotation limiting device for mechanically limiting the rotation of the steering wheel hub and, therefore, the steering wheel connected thereto. The steering wheel rotation limiting device may be configured to limit the rotatability of the steering wheel hub in both left and right circumferential directions about the rotation axis. The steering wheel rotation limiting device may still be configured to allow rotation of the steering wheel hub beyond 360°. The steering wheel rotation limiting device may be arranged radially offset relative to, and preferably adjacent to, the steering wheel hub.

[0022] The steering wheel rotation limiting device may include a base fixed to the above or another non-rotatable component of the steering system. The base may include two axially opposing dead-end surfaces. The steering wheel rotation limiting device may include a sliding element slidable axially between the opposing dead-end surfaces, parallel to the rotation axis, relative to the base and relative to the steering wheel hub. In other words, the sliding element may slide back and forth between the opposing dead-end surfaces.

[0023] The slider element may include a protrusion that engages a helical groove formed in the circumferential surface, preferably the outer circumferential surface, of the steering wheel hub such that rotation of the steering wheel hub causes axial movement of the slider element, and thus abutment of the slider element with one of the two dead end surfaces prevents further axial movement of the slider element in one direction, thereby preventing rotation of the steering wheel hub.

[0024] The steering handle rotation limiting device can be attached to the off-axis section via a base of the steering handle rotation limiting device and can engage the steering handle hub via a slider element, such that the steering handle rotation limiting device can extend axially toward the steering handle hub.

[0025] According to one aspect, a steering system for a vehicle includes a steering wheel hub connected or connectable to a steering wheel, the steering wheel hub and therefore the connected or connectable steering wheel being rotatable about a rotation axis.

[0026] The steering system includes a torque feedback device including an electric machine having a rotor and a stator, the rotor being mounted to the steering wheel hub for rotation therewith about a rotation axis, and the stator being fixed to a non-rotatable component of the steering system.

[0027] The steering system includes a steering wheel rotation limiting device for limiting rotation of the steering wheel hub. In particular, the steering wheel rotation limiting device is configured to mechanically limit or prevent rotation of the steering wheel in both circumferential directions about the rotation axis. Thus, the steering wheel rotation control device is configured to at least mechanically limit or prevent rotation of the steering wheel connected to the steering wheel hub. The steering wheel rotation limiting device can still allow rotation of the steering wheel hub and the steering wheel by more than 360°. The steering wheel rotation limiting device is radially offset from the steering wheel hub and preferably arranged near the steering wheel hub. The steering wheel rotation limiting device includes a base fixed to the above-mentioned or preferably another non-rotatable component of the steering system. The base includes two axially opposing dead-end surfaces with respect to a longitudinal axis parallel to the rotation axis. The steering wheel rotation limiting device further includes a sliding element slidable axially relative to the base and relative to the steering wheel hub, parallel to the rotation axis. The sliding element is slidable back and forth between the two opposing dead-end surfaces.

[0028] The sliding element includes a protrusion that engages with a helical groove formed on the circumferential surface of the steering wheel hub so that rotation of the steering wheel hub causes axial movement of the sliding element, and abutment of the sliding element with one of the two dead-end surfaces prevents movement of the sliding element and rotation of the steering wheel hub. The circumferential surface of the steering wheel hub that includes the helical groove can be an outer peripheral surface. More precisely, as the steering wheel hub rotates, the interaction and engagement of the protrusion with the helical groove causes the helical groove to drag the protrusion, thereby displacing the sliding element. The sliding element can then slide unless blocked by one of the two dead-end surfaces. Abutment of the sliding element with one of the two dead-end surfaces prevents further movement of the sliding element in one direction, and as a result, the interaction between the protrusion and the helical groove prevents further rotation of the steering wheel hub in one rotational direction. Thus, the abutment of the sliding element with one of the two dead end surfaces limits / restricts / stops the rotational movement of the steering wheel hub and the steering wheel fixedly connected thereto. In other words, the steering wheel limiting device defines and limits the maximum angle of rotation of the steering system about the rotation axis.

[0029] A steering wheel rotation limiting device that limits the rotation of the steering wheel hub based on abutment of a sliding element with one of two opposing dead end surfaces while allowing rotation of the steering wheel hub beyond 360° avoids oversizing of the electric machine of the torque feedback device because the electric machine does not need to provide a full stopping torque.

[0030] A steering wheel rotation limiting device that limits the rotation of the steering wheel hub based on the abutment of a sliding element with one of two opposing dead end surfaces provides a robust and reliable solution for providing mechanical dead end functionality in steer-by-wire systems that do not include a natural dead end structure.

[0031] Furthermore, the base and slide element arrangement is not very complex and can be easily manufactured and attached to the steering system.

[0032] A steering system with such a steering wheel rotation control can be flexibly installed in a variety of vehicles and can be simply adapted to various vehicle requirements.

[0033] The steering system may include a steering wheel.

[0034] In one embodiment, the base can have a compartment formed therein that accommodates the sliding element, thereby inhibiting or preventing radial movement of the sliding element away from the steering wheel hub and inhibiting or preventing lateral movement of the sliding element transverse to its direction of axial movement. In other words, the compartment can be configured to only allow axial movement of the sliding element between two opposing dead-end surfaces. The component can be partially complementary to the sliding element to inhibit radial movement of the sliding element away from the steering wheel hub and inhibit lateral movement of the sliding element transverse to its direction of axial movement. The compartment can be a cubic recess having five sides, two of which define two dead-end surfaces. Only the side of the cubic recess facing the steering wheel hub is not closed by a surface and is open to receive the sliding element and allow engagement of the helical groove with the sliding element (protrusion).

[0035] The base may be arranged radially adjacent to the steering handle such that the outer periphery of the base and steering handle hub completely surrounds the compartment.

[0036] According to one embodiment, the steering system can be configured such that when the slider element is in abutment against one of the two opposing dead-end surfaces, the protrusion is spaced from both end portions of the helical groove, preferably by a defined distance or a defined section of the helical groove. Thus, the limitation of rotation of the steering wheel hub is not caused by the interaction of the end portion of the helical groove with a portion of the protrusion, but by the abutment of one of the two dead-end surfaces with the surface of the slider element. Therefore, the abutment area is increased compared to known solutions. This prevents damage to the steering system, particularly to the helical groove and the protrusion, even under the influence of strong external forces.

[0037] The sliding element may have a substantially rectangular cross section. The protrusion may be a helical ridge protruding from the sliding element toward the steering wheel hub. The helical ridge may be matched to the helical groove, particularly with respect to the pitch of the helical groove. The helical ridge may be substantially complementary to a portion of the helical groove.

[0038] The axial width of the sliding element can be adapted according to 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 dead-end surfaces, and the circumferential length of the steering wheel hub. By adapting or selecting the axial width of the sliding element, the maximum stroke distance or maximum axial movement possibility of the sliding element between the two dead-end surfaces can be defined. Therefore, by simply replacing the sliding element and adapting its axial width and the size and shape of the protrusion, the steering wheel rotation limiting device can be flexibly used for various vehicle configurations.

[0039] The steering wheel rotation limiting device can be attached to said or preferably other non-rotatable components of the steering system by screws, bolts, rivets or adhesives, or can be welded to said or other non-rotatable components of the steering system. Attachment by screws or bolts can be advantageous as it allows the steering wheel rotation limiting device to be removably attached to the steering system.

[0040] In one embodiment, the base of the steering wheel rotation limiter can cover openings in the aforementioned or other non-rotatable components that provide access to electrical connections connecting the electric machine and / or at least one sensor to the electrical control unit. The sensor can be a steering wheel angle sensor. Thus, steering wheel rotation limiters, especially removably mounted steering wheel rotation limiters, can provide access to the electrical connections for maintenance while at the same time ensuring that the electrical connections and components are protected from harmful environmental influences.

[0041] 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 off-axis section having a first longitudinal axis that is offset from and preferably parallel to the rotation axis. The steering system support column may include an aligned section having a second longitudinal axis that is coincident with the rotation axis. In other words, coincident with the rotation axis may mean that the second longitudinal axis is aligned / coaxial with the rotation axis.

[0042] Each steering system support column offers a novel advantageous structural design that offers technical advantages in terms of space requirements, adjustability for driver ergonomics, and torque generation / transmission with low friction and inertia.

[0043] The combination of the above steering system support column design and steering wheel rotation limiting device: This contributes in particular to a structurally optimized design in terms of the reduction in space required, the robustness and reliability of the mechanical dead-end installation and the simple assembly of the steering system.

[0044] Furthermore, the structure of the steering system support column having an off-axis section and an aligned section and the steering wheel rotation limiting device described above together allows for optimized assembly and mounting of the steering wheel rotation limiting device described above.

[0045] The steering system support column can be integrally or one-piece formed. In particular, the off-axis section can be integrally connected to the alignment section by a connecting portion that extends transverse to both the first longitudinal axis and the second longitudinal axis.

[0046] The aligned section of the steering system support column can be a non-rotatable component to which the stator is attached, and the off-axis 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 arranged in the area of ​​the steering wheel hub, near the steering wheel, preferably directly on the steering wheel hub. This eliminates the need for a reduction gear train and gear shaft, reducing undesirable friction and inertia, and therefore increasing system efficiency.

[0047] In one embodiment, the steering system support column can be non-rotatable about its first longitudinal axis but translatably displaceable relative to the vehicle body along its longitudinal axis. The steering system support column can thus allow the steering system to be adjusted to suit the ergonomic needs of the driver. The steering system support column can preferably form an inner member of a tubular nesting arrangement. In this case, the steering support column can be translatably displaceable relative to an outer member. The steering system support column can be non-rotatable and non-pivotable relative to the outer member. The outer member can connect the steering system support column to the vehicle body.

[0048] According to one embodiment, the steering wheel hub can be rotatably mounted on the alignment section so that it at least partially overlaps the alignment section in an axial direction. The off-axis section can be axially spaced from the steering wheel hub.

[0049] In one embodiment of the steering system, the rotor can be an outer rotor and the stator can be an inner stator, in which case the rotor can be attached to the inner circumferential surface of the steering wheel hub, and the stator can be attached to the outer circumferential surface of the steering system support column, more precisely, to the outer circumferential surface of the alignment section.

[0050] 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 dead-end surfaces falls below a preset threshold, allowing rotation of the steering wheel hub / steering wheel to slow down to a certain extent before the sliding element fully abuts one of the two dead-end surfaces and abruptly prevents further rotation of the steering wheel hub / steering wheel. A threshold can be defined for each of the two dead-end surfaces.

[0051] According to one aspect, a steering system for a vehicle includes a steering wheel hub connected or connectable to a steering wheel, the steering wheel hub and therefore the connected or connectable steering wheel being rotatable about a rotation axis.

[0052] The steering system includes a torque feedback device including an electric machine having a rotor and a stator, the rotor mounted to the steering wheel hub for rotation therewith about a rotation axis, and the stator fixed to a non-rotatable component of the steering system.

[0053] The steering system includes a steering system support column including an off-axis section having a first longitudinal axis offset from, but preferably parallel to, the rotation axis, and an alignment section having a second longitudinal axis coincident with the rotation axis. Coincident with the rotation axis can also be described as aligned with or coaxial with the rotation axis. The steering wheel hub is rotatably mounted on the alignment section, so that it can at least partially overlap the alignment section in the axial direction. More precisely, the steering wheel hub can be rotatably mounted on an outer peripheral surface of the alignment section. The off-axis section is axially spaced from the steering wheel hub. The steering system support column can be rigid and formed integrally, i.e., in one piece.

[0054] The steering system includes a steering handle rotation limiting device for limiting rotation of the steering handle hub. In particular, the steering handle rotation limiting device is configured to at least mechanically limit or prevent rotation of the steering handle in both circumferential directions about the rotation axis. Thus, the steering handle rotation limiting device is configured to mechanically limit or prevent rotation of the steering handle connected to the steering handle hub. The steering handle rotation limiting device can still allow rotation of the steering handle hub and steering handle beyond 360°. The steering handle rotation limiting device is attached to the off-axis section via a base of the control handle rotation limiting device and engages with the steering handle hub via a sliding element. The steering handle rotation limiting device thus extends axially toward the steering handle hub, and the sliding element extends radially toward the steering handle hub. Preferably, the steering handle rotation limiting device can be attached only to the off-axis section of the steering system support column.

[0055] Each steering system support column provides a novel advantageous structural design that offers technical advantages in terms of space requirements, adjustability for driver ergonomics, and torque generation / transmission with low friction and inertia.

[0056] The combination of the steering system support column and the steering wheel rotation limiting device contributes to a structurally optimized configuration, particularly in terms of reduced space requirements, robustness and reliability of the mechanical dead-end integration, and simple assembly of the steering system.

[0057] Furthermore, the structure of the steering system support column having an off-axis section and an aligned section and the steering wheel rotation limiting device described above together allow for optimized assembly and mounting of the steering wheel rotation limiting device described above.

[0058] The off-axis section can be integrally connected to the alignment section by a connecting portion that extends across both the first longitudinal axis and the second longitudinal axis.

[0059] The alignment section of the steering system support column can be a non-rotatable component to which the stator is mounted. Thus, the torque feedback device can be located in the area of ​​the steering wheel hub and near the steering wheel, preferably directly on the steering wheel hub. This eliminates the need for a reduction gear train and gear shaft, reducing undesirable friction and inertia, and thus increasing system efficiency.

[0060] In one embodiment, the steering system support column can be non-rotatable about its first longitudinal axis and translatably displaceable along its first longitudinal axis relative to the vehicle body. The steering system support column thus allows the steering system to be adjustable to meet the ergonomic needs of the driver. The steering system support column can preferably form an inner member of a tubular nesting arrangement that is axially displaceable in, or translatably displaceable relative to, the outer member of the tubular nesting arrangement. The steering system support column can be non-rotatable and non-pivotable relative to the outer member. The outer member can connect the steering system support column to the vehicle body.

[0061] According to one embodiment, the steering system may comprise an electronic control unit for controlling at least the torque feedback device and / or for receiving and transmitting sensor information, particularly from a steering wheel angle sensor of the steering system.

[0062] The electronic control unit can be arranged inside the off-axis section of the steering system support column, thus allowing for efficient use of installation space.

[0063] The base of the steering wheel rotation limiter can cover an opening that provides access to an electric machine phase connection and / or a steering wheel sensor connection that connects an electric machine and / or at least one sensor with the electronic control unit at the off-axis section of the steering system support column. The sensor can be a steering wheel angle sensor. Thus, the steering wheel rotation limiter, especially a removably mounted steering wheel rotation limiter, can provide access to the electrical connections for maintenance while at the same time ensuring that the electrical connections and components are protected from harmful environmental influences.

[0064] The base of the steering wheel rotation limiting device can be attached to the off-axis section of the steering system support column by screws, bolts, rivets, or adhesives, or can be welded to the off-axis section of the steering support column. Attachment by screws or bolts allows for removable attachment to the steering system.

[0065] 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 circumferential 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 circumferential surface of the alignment section. The torque feedback device's outer rotor electric machine and its arrangement directly on the steering wheel hub and alignment section eliminates the need for a reduction gear train and gear shaft, reducing undesirable friction and inertia. This can increase system efficiency and reduce installation space requirements.

[0066] According to one embodiment, the base of the steering handle rotation limiting device can have two axially opposing dead end surfaces, and the sliding element can be axially slidable relative to the base and relative to the steering handle between the two opposing dead end surfaces parallel to the rotation axis.

[0067] The sliding element may be provided with a protrusion, in particular a helical ridge, which engages in a helical groove formed on the 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 dead end surfaces prevents further movement of the sliding element in one direction and further rotation of the steering wheel hub in the other direction.

[0068] The base can have a compartment formed therein that receives the sliding element and thereby inhibits radial movement of the sliding element away from the steering wheel hub and lateral movement of the sliding element transverse to its direction of axial displacement. The compartment can only permit axial movement of the sliding element between two opposing dead end surfaces.

[0069] The base may be arranged radially adjacent the steering wheel hub such that the outer periphery of the base and steering wheel hub completely surrounds the compartment.

[0070] The steering system can be configured so that, in a state or position where the sliding element abuts one of the two opposing dead-end surfaces, the protrusion is preferably spaced from both end portions of the spiral groove by a defined distance or by a defined section of the spiral groove. Therefore, the limitation of rotation of the steering wheel hub is not caused by the interaction of the end portion of the spiral groove with a part of the protrusion, but by the abutment of one of the two dead-end surfaces with the surface of the sliding element. Therefore, the abutment area can be increased compared to known solutions, thereby preventing damage to the steering system, particularly the spiral groove and the protrusion, even when subjected to strong external forces.

[0071] 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 dead-end surfaces falls below a preset threshold, allowing rotation of the steering wheel hub / steering wheel to slow down somewhat before the sliding element fully abuts one of the two dead-end surfaces and abruptly prevents further rotation of the steering wheel hub / steering wheel. A threshold can be defined for each of the two dead-end surfaces.

[0072] According to one aspect, a steering system for a vehicle includes a steering wheel hub connected or connectable to a steering wheel, the steering wheel hub and therefore the connected or connectable steering wheel being rotatable about a rotation axis.

[0073] The steering system includes a steering system support column including an off-axis section having a first longitudinal axis offset from and preferably parallel to the rotation axis, and an alignment section having a second longitudinal axis coincident with the rotation axis. Coincident with the rotation axis can also be described as being aligned with or coaxial with the rotation axis. The off-axis section and alignment section are integrally formed and connected by a connecting portion. The connecting portion is also integrally formed with the off-axis section and alignment section. Thus, the off-axis section, alignment section, and connecting portion are formed as a rigid, one-piece component. A steering wheel hub is rotatably mounted on the alignment section and axially at least partially overlaps the alignment section. The off-axis section is axially spaced from the steering wheel hub.

[0074] The steering system includes a torque feedback device including an electric machine having a rotor and a stator, the rotor fixedly mounted to the steering wheel hub for rotation therewith about a rotation axis, and the stator non-rotatably fixed to an alignment section of the steering system support column.

[0075] Preferably, the alignment section is stationary relative to the rotor and steering wheel hub and may form a hub element that supports the inner stator of the outer rotor electric machine.

[0076] The novel and advantageous structural design of the integrally formed or one-piece steering system support column including the off-axis section and the aligned section, combined with the torque feedback device arranged on the aligned section, allows for simple adjustment to suit driver ergonomics while optimizing the use of installation space, and simultaneously reduces friction and inertia due to torque generation / transmission.

[0077] Therefore, the combination of the steering system support column design and torque feedback device described above contributes to a structurally optimized configuration.

[0078] A connecting portion integrally formed with the off-axis section and the aligned section can extend across both the first longitudinal axis and the second longitudinal axis.

[0079] The off-axis segment, the alignment segment, and / or the connecting portion can be tubular. In particular, each of the off-axis segment, the alignment segment, and the connecting portion can be tubular. The off-axis segment, the alignment segment, and / or the connecting portion can have, at least in part, a substantially rectangular or circular cross-section. Alternatively, the off-axis segment, the alignment segment, and / or the connecting portion can have any other cross-sectional shape. For example, the off-axis segment, the alignment segment, and / or the connecting portion can have an elliptical or polygonal cross-section. A polygonal cross-section can be advantageous in that it provides several flat surfaces to provide an angular reference between the axially sliding and fixed portions of the nesting arrangement to prevent rotation relative to one another about the first longitudinal axis. The cross-sectional shapes of the off-axis segment, the alignment segment, and the connecting portion can be the same or different.

[0080] In one embodiment, the steering system support column can be attached to the vehicle body via a vehicle support column. The off-axis section of the steering system support column can be attached to the vehicle support column so as to be translatable along the first longitudinal axis and non-rotatable and non-pivotable relative to the vehicle support column. That is, in this embodiment, the steering system support column and all components supported thereon are displaceable / non-displaceable relative to the vehicle support column. The steering system support column can be attached to the vehicle support column by a bracket, an axial adjustment element, and / or a vertical adjustment element.

[0081] Support for the off-axis section of the steering system support column in the vehicle support column can be provided at a first end of the steering system support column (i.e., the end away from the alignment section) opposite a second end of the steering system support column at which the torque feedback device is aligned.

[0082] This configuration eliminates the need for a reduction gear train and gear shaft, reducing friction and inertia during torque generation and transmission for the steer-by-wire system, while allowing the steering system to be adjusted to suit driver ergonomics.

[0083] The steering system support column may form an inner member of a tubular nesting array and the vehicle support column may form an outer member of the tubular nesting array, the inner member being axially translatably mounted within the outer member of the tubular nesting array.

[0084] The vehicle support column and steering system, i.e., any additional system components mounted on or to the steering system support column, may be pivotable and / or radially displaceable relative to the vehicle body, making them adjustable relative to the vehicle body. The pivotability and / or radial displaceability may be associated with movement of at least a portion of the steering system support column along at least one transverse axis intersecting the first longitudinal axis.

[0085] According to one embodiment, the steering system support column can have openings, preferably arranged in the off-axis section or connection portion, that allow access to an electric machine phase connection and / or a steering wheel angle sensor connection that connects the electric machine and / or at least one sensor with the electronic control unit. The sensor can be a steering wheel angle sensor. Thus, the steering wheel rotation limiting device, especially a removably mounted steering wheel rotation limiting device, can make the electrical connections accessible for maintenance, while at the same time ensuring that the electrical connections and components are protected from harmful environmental influences.

[0086] According to one embodiment, the steering system can include an electronic control unit for controlling at least the torque feedback device and / or for transmitting and receiving sensor information, such as information from a steering wheel angle sensor. The electronic control unit can be arranged within an 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 near the stator windings of the torque feedback electric machine and / or near a sensor, such as a rotation angle sensor, for measuring the rotation of the electric machine rotor.

[0087] In one embodiment, the steering system can include auxiliary components arranged within the stator of the torque feedback electric machine according to the alignment section of the steering system support column. The auxiliary components can include an airbag module, a switchgear control, a driver display arrangement, and / or a wiring harness. By arranging the auxiliary components within the steering system support column, installation space can be used efficiently, i.e., the overall installation space required for the steering system can be reduced.

[0088] 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 mounted on the inner circumferential surface of the steering wheel hub. The stator can be mounted on the outer circumferential surface of the steering system support column, more precisely, on the outer circumferential surface of the alignment section. The outer rotor electric machine of the torque feedback device and its direct arrangement on the steering wheel hub and alignment section eliminates the need for a reduction gear train and gear shaft, reducing undesirable friction and inertia. This can increase system efficiency and reduce required installation space.

[0089] According to one embodiment, the alignment section of the steering system support column can include 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 alignment section and the connection section, i.e., at an end portion of the alignment section facing away from a steering wheel connected or connectable to the steering system. The protruding flange portion provides a circular annular first bearing surface. The protruding flange portion allows the outer diameter of the main portion of the alignment section to be minimized while supporting a steering wheel hub having a substantially larger inner diameter.

[0090] The alignment section of the steering system support column may comprise a circular annular portion that provides a circular annular second bearing surface for a second bearing arrangement arranged between the steering system support column and the steering wheel hub. Preferably, the circular annular portion may be arranged at least in an area following or adjacent to the steering wheel connected or connectable to the steering system, in other words at least in an area facing away from the off-axis section and the connecting portion. The circular annular portion allows the outer shape / contour of the main part of the alignment section to be freely selected while rotatably supporting the steering wheel.

[0091] The first and second bearing arrangements provide rotatable support for the steering wheel hub and connected steering wheel on the steering system support column.

[0092] In one embodiment, the steering system can include a steering wheel rotation limiting device for at least mechanically limiting rotation of the steering wheel hub in both circumferential directions about the rotation axis. 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.

[0093] The base of the steering wheel rotation limiting device has two axially opposed dead end surfaces, and the slider is axially slidable between the two opposed dead end surfaces relative to the base and relative to the steering wheel hub parallel to the rotation axis. The slider can have a protrusion, in particular a helical ridge, that engages with a helical groove formed in the outer peripheral surface of the steering wheel hub so that rotation of the steering wheel hub causes axial movement of the slider, and abutment of the slider with one of the two dead end surfaces prevents further movement of the slider and therefore further rotation of the steering wheel hub.

[0094] The base of the steering wheel rotation limiting device can overlap the first bearing surface according to the protruding flange portion in the axial direction relative to the rotation axis, thus achieving an advantageous and compact design of the steering system structure.

[0095] According to one aspect, a steering system for a vehicle includes a steering wheel and a steering wheel hub, the steering wheel being mechanically attached to the steering wheel hub by fastening elements. Preferably, the steering wheel is directly and fixedly attached to the steering wheel hub. The fastening elements can be bolts and / or screws. Preferably, a total of 3 to 10 screws can be equidistantly arranged around the rotational axes of the steering wheel and the steering wheel hub.

[0096] The steering system includes a steering system support column, and a 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 rotation axis.

[0097] The steering system includes a torque feedback device including an electric machine having an outer rotor and an inner stator with stator windings. The outer rotor is mounted to the 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.

[0098] The fixed elements are arranged at a different radial position relative to the axis of rotation than the rotor windings, i.e., the fixed elements are arranged at a different radial height relative to the axis of rotation than the stator windings, i.e., the fixed elements are arranged at a different radial position from the axis of rotation than the stator windings.

[0099] Locating the outer rotor electric machine for the torque feedback device and arranging the fixed elements at a different radial location from the stator windings allows for an advantageously compact design of the steer-by-wire steering system that reduces the required installation space.

[0100] A portion of the fixed element can overlap a portion of the stator winding in the axial direction with respect to the rotation axis. In particular, a portion of each of the fixed elements, or only one or a portion of a specific fixed element, can overlap a portion of the stator winding in the axial direction with respect to the rotation axis. Such an arrangement is possible by arranging the fixed elements at a different radial position from the stator winding. Therefore, at least a portion of the fixed element can be arranged parallel to the stator winding, which further contributes to a compact structure of the steering system.

[0101] According to one embodiment, the steering system can include a first bearing arrangement arranged between the steering system support column and the steering wheel hub to allow rotation of the steering wheel hub relative to the steering system support column. The steering system can include a second bearing arrangement arranged between the steering system support column and the steering wheel hub to allow rotation of the steering wheel hub relative to the steering system support column. The second bearing arrangement can be axially spaced apart from the first bearing arrangement with respect to the axis of rotation. The second bearing arrangement can be positioned closer to the steering wheel than the first bearing arrangement.

[0102] The first bearing arrangement can be arranged at a different radial position relative to the axis of rotation than the second bearing arrangement. In this case, a "different radial position" can also be described as having a different radial height relative to the axis of rotation, i.e., a different radial distance from the axis of rotation. By arranging the second bearing arrangement at a different radial position relative to the first bearing arrangement, i.e., closer to the axis of rotation, it is possible to arrange additional components parallel to the second bearing arrangement in an overlapping manner. This contributes to a more compact design.

[0103] With respect to the axis of rotation, the fixed element can be arranged at a different radial position than the first bearing arrangement and / or the fixed element can be arranged at a different radial position than the second bearing arrangement. Such an arrangement allows for an overlapping / parallel arrangement of the components of the steering system, which further contributes to a compact design of the steering system and a reduction in the required installation space.

[0104] In one embodiment, the steering system support column, particularly the alignment section of the steering system support column, can include an outwardly protruding flange portion that provides a circular annular first bearing surface for the first bearing arrangement. The protruding flange portion that protrudes from the outer peripheral surface of the steering system support column is preferably arranged in a transition region between the alignment section and the connecting section of the steering system support column. The protruding flange portion allows the outer diameter of the main portion of the alignment section to be minimized while supporting a steering wheel hub having a substantially larger inner diameter.

[0105] The steering system support column, in particular the alignment section of the steering system support column, can have a circular annular portion providing a circular annular second bearing surface for the second bearing arrangement. The circular annular portion providing the second bearing surface can have an outer diameter substantially smaller than that of the protruding flange portion. The circular annular portion can be located at least in an area behind or adjacent to the steering wheel, i.e., at least in an area facing away from the off-axis section. By means of the circular annular portion, the outer shape / contour of the main section of the alignment section can be freely selected while still rotatably supporting the steering wheel.

[0106] In one embodiment, the fixed element can overlap the second bearing arrangement axially with respect to the axis of rotation. The fixed element can overlap the second bearing arrangement partially or completely, which contributes to a compact design of the steering system and a reduction in the required installation space.

[0107] The steering wheel hub may include an inwardly projecting flange portion that provides a counter-bearing surface for the second bearing arrangement, the counter-bearing surface being substantially opposite the second bearing surface. By inwardly projecting, it is meant that the inwardly projecting flange portion projects toward the steering system support column, i.e., toward the axis of rotation. The counter-bearing surface forms a circular annulus for supporting the second bearing arrangement.

[0108] The inwardly protruding flange portion of the steering wheel hub can be formed in a region of the steering wheel hub that is axially arranged between the steering wheel and the electric machine of the torque feedback device, so that the electric machine can be covered toward the steering wheel by the inwardly protruding flange portion.

[0109] A blind hole can be formed in the steering wheel hub in the region of the inwardly projecting flange portion, preferably in the inwardly projecting flange portion, and a fastening element can extend into the blind hole for fastening the steering wheel to the steering wheel hub. The blind hole can be provided with an internal thread for fastening a fastening element in the form of a screw or threaded bolt therein.

[0110] In one embodiment, the fixed element can be arranged at substantially the same radial position as the outer rotor of the torque feedback device relative to the axis of rotation. Such a configuration can limit the radial dimension of the steering system in the region of the torque feedback device.

[0111] According to one embodiment, the steering handle can include a rigid steering handle armature including a through hole, and a fastening element can extend through the through hole and into the steering handle hub for fastening the steering handle to the steering handle hub. Preferably, the through hole can be aligned with a blind hole in the steering handle hub.

[0112] According to one embodiment, the steering system support column can include an off-axis section having a first longitudinal axis that is offset from, and preferably parallel to, the axis of rotation, and an alignment section having a second longitudinal axis that is coincident with the axis of rotation. The off-axis section and the alignment section can be integrally formed and connected by a connecting portion. The steering wheel hub can be rotatably mounted on the alignment section so that it at least partially axially overlaps the alignment section, and the off-axis section is axially spaced from the steering wheel hub. The stator can be non-rotatably fixed to the alignment section of the steering system support column.

[0113] In one embodiment, the steering system may include a steering wheel rotation limiting device for limiting rotation of the steering wheel hub. In particular, the steering wheel rotation limiting device may be configured to at least mechanically limit or prevent rotation of the steering wheel hub in both circumferential directions about the rotation axis. Thus, the steering wheel rotation limiting device may be configured to mechanically limit or prevent rotation of the steering wheel connected to the steering wheel hub. The steering wheel rotation limiting device may still allow rotation of the steering wheel hub and steering wheel in excess of 360°. The steering wheel rotation limiting device may be attached to the off-axis section via a base of the steering wheel rotation limiting device and may engage with the steering wheel hub via a sliding element. The steering wheel rotation limiting device may thus 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 off-axis section of the steering system support column.

[0114] Although some of the features, functions, embodiments, technical effects and advantages have been described with respect to one embodiment, it should be understood that these features, functions, embodiments, technical effects and advantages may be combined with one another and applied to other embodiments and embodiments. [Brief explanation of the drawings]

[0115] For a better understanding of embodiments of the present invention and to show how the same may be carried into effect, reference will now be made, purely by way of example, to the accompanying drawings in which like numerals indicate corresponding elements or sections throughout, and in which:

[0116] [Figure 1] FIG. 1 is a schematic cross-sectional view of a steering system according to one embodiment of the present invention. [Figure 2] FIG. 2 is a schematic side view of the steering system of FIG. [Figure 3] FIG. 3 is a schematic perspective view of the steering system of FIG. [Figure 4]FIG. 4 is another schematic perspective view of the steering system of FIG. [Figure 5] FIG. 5 is yet another schematic perspective view of the steering system of FIG. [Figure 6] FIG. 6 is a further schematic perspective view of the steering system of FIG. [Figure 7A] FIG. 7A shows a steering wheel rotation limiting device of a steering system in a schematic exploded state. [Figure 7B] FIG. 7B shows the steering wheel rotation limiting device of the steering system in an assembled state. [Figure 7C] FIG. 7C shows the steering wheel rotation limiting device of the steering system in an installed state. [Figure 8A] FIG. 8A is a schematic diagram of a steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 8B] FIG. 8B is a schematic diagram of the steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 8C] FIG. 8C is a schematic diagram of the steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 8D] FIG. 8D is a schematic diagram of a steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 8E] FIG. 8E is a schematic diagram of the steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 8F] FIG. 8F is a schematic diagram of a steering wheel rotation limiting device to illustrate the functioning principle of the steering wheel rotation limiting device. [Figure 9A] FIG. 9A is a schematic diagram of a steering wheel rotation limiter and a steering wheel hub to illustrate the functioning principle of the steering wheel rotation limiter. [Figure 9B] FIG. 9B is a schematic diagram of the steering wheel rotation limiter and steering wheel hub to illustrate the functioning principle of the steering wheel rotation limiter. [Figure 9C]FIG. 9C is a schematic diagram of the steering wheel rotation limiter and steering wheel hub to illustrate the functional principle of the steering wheel rotation limiter. DETAILED DESCRIPTION OF THE INVENTION

[0117] Various examples of embodiments of the present invention are explained in further detail by the following embodiments illustrated in the drawings and / or described below.

[0118] 1-6 are schematic diagrams of a steering system 10 for a road vehicle in accordance with one embodiment of the present invention. As can be seen from FIGURES 1-6, the steering system 10 is a steer-by-wire steering system that does not have any direct mechanical connection for transmitting a driver's steering commands from the steering wheel 12 to the wheels (not shown) of the steering system 10. Instead, the mechanical connection is replaced by an electro-mechanical arrangement.

[0119] In addition to the steering handle 12, the steering system 10 comprises a steering handle hub 14 mechanically connected to the steering handle 12. The steering handle hub 14 and the steering handle 12 are non-rotatable relative to each other and can rotate together about a rotation axis A. The steering handle 12 is non-rotatably attached to the steering handle hub 14 by a fixing element 16 in the form of a screw. More precisely, the steering handle 12 comprises an internal armature 18, the fixing element 16 extending through a through hole 20 in the internal armature 18 into an internally threaded bore 22 provided in the steering handle hub 14.

[0120] The steering wheel hub 14 is rotatably supported on a rigid steering system support column 24 of the steering system 10, more precisely on an alignment section 26 of the steering system support column 24. In addition to the alignment section 26, the steering system support column 24 includes an off-axis section 28 integrally formed with the alignment section 26. The off-axis section 28 is axially spaced from the alignment section 26 and from the steering wheel hub 14, while the steering wheel hub 14 overlaps and is coaxially disposed with the alignment section 26. The off-axis section 28 has a first longitudinal axis L1 that is offset from and parallel to the rotation axis A. The alignment section 26 has a second longitudinal axis L2. The alignment section 26 of the steering system support column 24 is aligned or coaxial with the steering wheel hub 14 and the steering wheel 12. That is, the second longitudinal axis L2 coincides with the rotation axis A.

[0121] The off-axis section 28 and the aligned section 26 are integrally formed and connected by a connecting portion 30 that extends transversely to both the first longitudinal axis L1 and the second longitudinal axis L2.

[0122] The steering wheel hub 14 is rotatably mounted to the alignment section 26 of the steering system support column 24 by a first bearing array 32 and a second bearing array 34, the second bearing array 34 being axially spaced from the first bearing array 32. For example, the first bearing array 32 and / or the second bearing array 34 may be ball bearings or roller bearings.

[0123] The first bearing arrangement 32 is supported on a protruding flange portion 36 of the alignment section 26 of the steering system support column 24. The protruding flange portion 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 arrangement 32. The protruding flange portion 36 is arranged near the connection portion 30, i.e., in the transition region between the alignment section 26 and the connection portion 30. Thus, the first bearing arrangement 32 is axially disposed at a first end of the alignment section 26 facing toward the connection portion 30.

[0124] The second bearing arrangement 34 is supported on a circular annulus portion 38 of the alignment section 26 of the steering system support column 24. The circular annulus portion 38 is formed in the area of ​​the alignment section 26 that follows the steering wheel 12 and extends toward the protruding flange portion 36. The circular annulus portion 38 provides a second bearing surface for the second bearing arrangement 34. As such, the second bearing arrangement 34 is axially disposed at a second end portion of the alignment section 26 opposite the first end portion.

[0125] The first bearing arrangement 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 arranged between the first bearing arrangement 32 and the inner peripheral surface of the steering wheel hub 14.

[0126] The second bearing arrangement 34 is mounted directly between the circular annular portion 38 of the alignment section 26 and the steering wheel hub 14. To this end, the steering wheel hub 14 includes an inwardly projecting flange portion 42 that provides a counter-bearing surface for the second bearing arrangement 34. At the same time, the inwardly projecting flange portion 42 covers components disposed inside the steering wheel hub 14. As can be seen in FIG. 1 , the blind hole 22 for receiving the fastening element 16 extends into or through the inwardly projecting flange portion 42.

[0127] The steering system 10 further includes a torque feedback device 44 that includes an electric machine 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 so as to mimic 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.

[0128] In the illustrated embodiment, the electric machine is an external rotor electric machine comprising an external rotor 46 and an internal stator 48. The rotor 46 is fixed to the circumferential surface of the steering wheel hub 14. Thus, the rotor 46 is rotatable together with the steering wheel hub 14 about a rotational axis A. The rotor 46 is non-rotatable relative to the steering wheel hub 14. The stator 48 is fixed to the alignment section 26, which is stationary (i.e., non-rotatable) with respect to the rotation 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 alignment section 26.

[0129] The electric machine of the torque feedback device 44 is arranged inside the steering wheel hub 14. The torque feedback device 44 is radially surrounded and covered by the steering wheel hub 14 (the inner peripheral surface of the steering wheel hub 14) and the alignment section 26 (the outer peripheral surface of the alignment section 26) of the steering system support column 24. The torque feedback device 44 is axially disposed between the protruding flange portion 36 of the alignment section 26 and the circular annular portion 38 of the alignment section 26. The torque feedback device 44 is axially surrounded and covered on one side by the protruding flange portion 36 of the alignment section 26, the first bearing arrangement 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 arrangement 34.

[0130] The arrangement, configuration and support of the steering wheel hub 14, steering wheel 12, torque feedback device 44 and steering system support column 24 provides a very compact structure. More precisely, as shown in FIG. 1, the various components are arranged at least partially parallel to one another with respect to their radial and / or axial alignment.

[0131] That is, the fixed element 16 is arranged at a different radial position, i.e., a different radial height, from the stator windings 50 with respect to the rotation axis A. Therefore, the fixed element 16 and the blind holes 22 at least partially overlap the stator windings 50 in the axial direction. The stator windings 50 can be arranged closer to the rotation axis A than the fixed element 16.

[0132] Furthermore, the second bearing arrangement 34 is disposed at a different radial position or height relative to the axis of rotation A than the stator windings 50 and at a different radial position or height relative to the fixed element 16. In the illustrated embodiment, the fixed element 16 axially overlaps the second bearing arrangement 34. The second bearing arrangement 34 can be disposed closer to the axis of rotation A than the stator windings 50 and closer to the axis of rotation A than the fixed element 16.

[0133] Furthermore, the first bearing arrangement 32 is arranged at a different radial position or height with respect to the rotation axis A than the second bearing arrangement 34 and at a different radial position or height with respect to the stationary element 16. The first bearing arrangement 32 is arranged at the same radial position with respect to the rotation axis A as the stator windings 50. The first bearing arrangement 32 can be arranged closer to the rotation axis A than the stator stationary element 16 and farther from the rotation axis A than the second bearing arrangement 34.

[0134] The fixed element 16 is arranged at the same radial position as the outer rotor 46 of the torque feedback device 44 with respect to the rotation axis A. This limits the radial dimension of the steering system 10 in the region of the torque feedback device 44.

[0135] The steering system 10 further includes a steering wheel rotation limiting device 52 for limiting rotation of the steering wheel hub 14 and the steering wheel 12. The steering wheel rotation limiting device 52 is fixed to the steering system support column 24 and is radially offset from the steering wheel hub 14, specifically, arranged adjacent to the outer circumferential surface of the steering wheel hub 14. The steering wheel rotation limiting device 52 is non-rotatable relative to the steering system support column 24.

[0136] The steering wheel rotation limiting device 52 includes a base 54 and a sliding element 56 disposed within a compartment 58 formed in the base 54. The sliding element 56 is axially slidable relative to the base 54 and relative to the steering wheel hub 14. The sliding element 56 is slidable between two opposing dead-end surfaces 60, 62 (FIGS. 7A-9C) of the steering wheel rotation limiting device 52. The sliding element 56 includes a protrusion 64 that engages with a helical groove 66 formed in the outer circumferential surface of the steering wheel hub 14. Due to 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 dead-end surfaces 60, 62 prevents further movement of the sliding element 56 in a particular direction, thereby preventing further rotation of the steering wheel hub 14 in a particular rotational direction. Thus, the steering wheel rotation limiting device 52 is configured to limit the rotation of the steering wheel hub 14 and the steering wheel 12 connected thereto.

[0137] The base 54 of the steering wheel rotation limiting device 52 is fixed to the off-axis section 28 of the steering system support column 24 by screws 68 (FIGS. 5-9C). The steering wheel rotation limiting device 52, or more precisely the base 54, extends axially from the off-axis section 28 of the steering system support column 24 to the steering wheel hub 14, such that a compartment 58 is arranged between and surrounded by the outer circumferential surface of the base 54 and the steering wheel hub 14.

[0138] The function and further details of the steering wheel rotation limiting device 52 are described in connection with Figures 7A-9C.

[0139] The base 54 of the steering wheel rotation limiting device 52 covers an opening 70 formed in the off-axis section 28 of the steering wheel support column 24. More precisely, the opening 70 is arranged in another transition area between the off-axis section 28 and the connecting portion 30. The opening 70 allows access for maintenance to an electro-mechanical phase connection 72 and an electrical steering wheel angle sensor connection 74. The electro-mechanical phase connection 72 connects the electric machine of the torque feedback device 44 with a control unit / control electronics 76. The electrical steering wheel angle sensor connection 74 connects a steering wheel angle sensor 78 with the control unit / control electronics 76.

[0140] The control unit 76 is arranged inside the hollow tubular off-axis section 28 of the steering system support column 24. More precisely, the control unit 76 is arranged in a portion of the off-axis section 28 near the connection portion 30 so that the control unit 76 and the electric machine are located close to each other.

[0141] The steering wheel angle sensor 78 is configured to measure the current steering angle and thus detect the driver's steering command, which is electrically transmitted to the actuator to actuate / steer the wheels accordingly. The steering wheel angle sensor 78 is arranged adjacent to or to the side of the first bearing arrangement 32.

[0142] The steering system support column 24 forms the inner member of a tubular nesting array 80. The outer member of the tubular nesting array 80 is embodied by a vehicle support column 82. In particular, the off-axis section 28 is axially slidably mounted within the outer member / vehicle support column 82 of the tubular nesting array 80. Thus, the steering system support column 24 is translationally displaceable relative to the vehicle support column 82 and relative to the vehicle body, but is non-rotatable and non-pivotable relative to the vehicle support column 82.

[0143] The steering system support column 24 is connected to the vehicle body (not shown) via the vehicle support column 82 by brackets, axial adjustment elements, and vertical adjustment elements 84. Therefore, the steering system support column 24 and all components supported thereon are translationally displaceable only about the first longitudinal axis L1, independent of the vehicle support column 82. Furthermore, the steering system support column 24 and all components supported thereon are radially displaceable / rotatable relative to the vehicle support column 82, i.e., the vehicle body, depending on the adjustability / displaceability of the vehicle support column 82.

[0144] The steering system support column 24 has a hollow tubular shape. The steering system support column 24 is formed as a rigid, one-piece component and is preferably made of metal. As can be seen from Figures 3-6, which show various perspective views of the steering system 10, at least the off-axis section 28 of the steering system support column 24 has a substantially rectangular cross-section. Such a shape is particularly advantageous for accommodating and mounting the control unit 76. Similar to the off-axis section 28, the vehicle support column 82, which forms the annular nesting array 80 with the off-axis section 28, also has a substantially rectangular cross-sectional area.

[0145] The connecting portion 30 of the steering system support column 24 forms a tapered transition from the off-axis section 28 to the alignment section 26. The alignment section 26 has a smaller diameter than the off-axis section 28. The alignment section 26 has a substantially circular cross-sectional area.

[0146] 3 and 5, in conjunction with FIG. 1, the steering wheel 12 includes an interior space 86 for accommodating auxiliary components (not shown), such as an airbag module, switchgear controls, a driver display array, etc. These auxiliary components, as well as other auxiliary components such as wire harnesses, may extend into the hollow tubular alignment section 26. The auxiliary components, as well as other auxiliary components, may thus be arranged within and / or attached to the alignment section 26 of the steering system support column 24.

[0147] 7A-7C are intended to disclose details regarding the function and construction of the steering wheel rotation limiting device 52. FIG. 7A shows the components of the steering wheel rotation limiting device 52 separately or in an exploded view. FIG. 7B shows the components of the steering wheel rotation limiting device assembled. FIG. 7C shows the steering wheel rotation limiting device 52 attached to or interacting with the steering wheel hub 14.

[0148] As can be seen in Figures 7A-7C, four screws 68 extend through the base 54 to securely fasten the steering wheel rotation limiting device 52 to the steering system support column 24. A compartment 58 is formed within the base 54. Two axially opposing side surfaces of the compartment 58 form dead-end surfaces 60, 62. The compartment 58 is formed to be partially complementary to the sliding element 56 that can be arranged therein (Figure 7B). Thus, the compartment 58, or more precisely, the bottom and side surfaces of the compartment 58, limit the axial sliding movement of the sliding element 56 to axial sliding movement (arrow AS) between the two dead-end surfaces 60, 62. The two dead-end surfaces 60, 62 limit the axial sliding movement of the sliding element 56. When the sliding element 56 abuts one of the two dead-end surfaces 60, 62, further movement of the sliding element in the current direction is prevented and the sliding element 56 can only move in the opposite axial direction, i.e., toward the respective opposite dead-end surface 60, 62. The surface facing the steering wheel hub 14 in the mounted state is curved and substantially complementary to a corresponding portion of the outer circumferential surface of the steering wheel hub 14.

[0149] The sliding element 56 engages with a helical groove 66 formed on the outer periphery of the steering wheel hub 14 via a protrusion 64. The protrusion 64 is formed as a helical ridge to match the shape and dimensions of the helical groove 66. The sliding element 56 interacts with the steering wheel hub 14 via the helical groove 66. As 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 the rotation of the steering wheel hub 14 stops or until further movement is prevented by engagement of the sliding element 56 with one of the two dead-end surfaces 60, 62. Thus, preventing further axial movement of the sliding element 56 prevents further rotation of the steering wheel hub 14, and therefore the steering wheel 12, in a rotational direction that would result in further axial movement of the sliding element 56 toward the currently blocking dead-end surface 60, 62.

[0150] As shown in FIG. 7A , the sliding element 56 has an axial width W. The axial width W of the sliding element 56 defines the free space within the compartment 58 between the sliding element 56 and the dead-end surfaces 60, 62. Therefore, by adapting or selecting the axial width W of the sliding element 56, the maximum stroke distance, i.e., the maximum axial movement capability, of the sliding element 56 between the two dead-end surfaces 60, 62 can be adjusted. Therefore, by simply replacing the sliding element 56 and adapting its axial width W and the size and shape of the protrusion 64, the steering wheel rotation limiting device 56 can be flexibly used in various vehicle configurations. In particular, the axial width W can be selected depending 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 dead-end surfaces 60, 62, and the circumferential length of the steering wheel hub 14.

[0151] The abutment of the sliding element 56 with the dead-end surface 60 is shown in Figures 8A, 8B, and 9A. In this position, the sliding element 56 can only slide toward the opposite dead-end surface 62. That is, in this position, the steering wheel hub 14 and steering wheel 12 can only rotate in one specific rotational direction, which moves the sliding element 56 toward the opposite dead-end surface 62. A position in which the sliding element 56 is free to slide in both axial directions is shown in Figures 8C, 8D, and 9B. That is, in this position, the steering wheel hub 14 and steering wheel 12 can freely rotate in both rotational directions. The abutment of the sliding element 56 with the opposite dead-end surface 62 is shown in Figures 8E, 8F, and 9C. In this position, the sliding element 56 can only slide toward the dead-end surface 60. That is, in this position, the steering wheel hub 14 and steering wheel 12 can only rotate in one specific rotational direction that moves the sliding element 56 toward the dead end surface 60 .

[0152] 9A, at the position where the slider element abuts one of the two opposing dead-end surfaces, the protrusion 64 is spaced from the nearest end portion 88 of the helical groove 66. Thus, the limitation of rotation of the steering wheel hub 14 is not caused by the abutment of the end portion 88 of the helical groove 66 with the protrusion 64, but by the abutment of the slider element 56 with one of the two dead-end surfaces 60, 62. This robust configuration prevents damage to the steering system 10, and in particular to the helical groove 66 and the protrusion 64, even under the influence of strong external forces. [Explanation of symbols]

[0153] 10. Steering System 12 Control handle 14 Steering wheel hub 16 Fixed Elements 18 Armature 20 through holes 22 Blind hole 24 Steering system support column 26 Alignment Division 28 Off-Axis Division 30 Connection part 32 First bearing array 34 Second bearing array 36 Protruding flange part 38 Circular annular part 40 Support bushing 42 Inward-protruding flange portion 44 Torque Feedback Device 46 rotor 48 Stator 50 stator winding 52 Control handle rotation limiting device 54 base 56 Sliding element 58 compartments 60 Dead End 62 Dead End 64 Projection 66 helical groove 68 Screw 70 aperture 72 Electromechanical phase connection 74 Electric steering wheel angle sensor connection 76 Control Unit 78 Steering wheel angle sensor 80 Circular Nested Arrays 82 Vehicle support column 84 Adjustment element 86 Interior Space 88 End part L1 First longitudinal axis L2 Second longitudinal axis A rotation axis AS axial direction W Axial width

Claims

1. A steering system (10) for a vehicle, comprising: a steering wheel hub (14) connected or connectable to the steering wheel (12), said steering wheel hub (14) being rotatable about a rotation axis (A); a torque feedback device (44) including an electric machine 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); a steering wheel rotation limiting device (52) for limiting the rotation of the steering wheel hub (14); Equipped with the rotor (46) is an outer rotor, the stator (48) is an inner stator, the steering wheel rotation limiting device (52) is arranged radially offset relative to the steering wheel hub (14), and a base (54) fixed to the or another non-rotatable component (26) of the steering system (10), the base (54) having two opposing dead end surfaces (60, 62); a sliding element (56) axially slidable relative to the base (54) and relative to the steering wheel hub (14) parallel to the rotation axis between the two opposing dead end surfaces (60, 62); Equipped with the sliding element (56) has a protrusion (64) that engages with a helical groove (66) formed in the circumferential 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 dead end surfaces (60, 62) prevents movement of the sliding element (56) and rotation of the steering wheel hub (14). characterized in that Steering system (10).

2. 2. The steering system of claim 1, wherein the base includes a compartment formed therein that receives the sliding element and thereby inhibits radial movement of the sliding element away from the steering wheel hub and lateral movement of the sliding element transverse to its direction of axial movement.

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

4. 4. A steering system (10) according to at least one of claims 1 to 3, wherein the protrusion (64) is spaced apart from an end portion (88) of the spiral groove (66) when the sliding element (56) abuts against one of the two opposing dead end surfaces (60, 62).

5. A steering system (10) according to at least one of claims 1 to 4, wherein the sliding element (56) has a substantially rectangular cross-sectional area and / or the protrusion (64) is a helical ridge.

6. 6. A steering system (10) according to at least one of claims 1 to 5, wherein the axial width (W) of the sliding element (56) is adapted depending on one or more of the following parameters: the length of the spiral groove (66), the pitch of the spiral groove (66), the distance between the two opposing dead-end surfaces (60, 62), and the circumferential length of the steering wheel hub (14).

7. 7. The steering system (10) of claim 1, wherein the steering wheel rotation limiting device (52) is attached to the or other non-rotatable component (28) of the steering system (10) by a screw (68), a bolt, a rivet, or an adhesive, or is welded to the or other non-rotatable component (28) of the steering system (10).

8. 8. A steering system (10) according to at least one of claims 1 to 7, wherein the base (54) of the steering wheel rotation limiting device (52) covers an opening (70) in the or other non-rotatable component (28) that allows access to electrical connections (72, 74) connecting the electric machine and / or at least one sensor (78) with an electronic control unit (76).

9. 9. The steering system (10) of claim 1, further comprising a steering system support column (24) comprising an off-axis section (28) having a first longitudinal axis (L1) offset with respect to the axis of rotation (A) and an aligned section (26) having a second longitudinal axis (L2) coincident with the axis of rotation (A).

10. 10. The steering system (10) of claim 9, wherein the off-axis section (28) is integrally connected to the alignment section (26) by a connecting portion (30) that extends across both the first longitudinal axis (L1) and the second longitudinal axis (L2).

11. 11. The steering system (10) of claim 9 or 10, wherein the aligned section (26) of the steering system support column (24) is the non-rotatable component to which the stator (48) is attached, and the off-axis section (28) is the other non-rotatable component to which the base (54) of the steering wheel rotation limiting device (52) is attached.

12. 12. The steering system (10) according to at least one of claims 9 to 11, wherein the steering system support column (24) is non-rotatable but translatably displaceable along its first longitudinal axis (L1), and the steering system support column (24) forms an inner member of a tubular nesting arrangement (80).

13. 13. The steering system (10) of claim 9, wherein the steering wheel hub (14) is rotatably mounted on the alignment section (26), and the off-axis section (28) is axially spaced from the steering wheel hub (14).

14. the steering system further comprising a first bearing arrangement (32) arranged between the steering system support column (24) of the steering system (10) and the steering wheel hub (14) to allow rotation of the steering wheel hub (14) relative to the steering system support column (24) of the steering system (10); the steering system support column (24) having an outwardly projecting flange portion (36) providing a circular annular first bearing surface for the first bearing arrangement (32); the base (54) of the steering wheel rotation limiting device (52) overlaps the protruding flange portion (36) in the axial direction relative to the rotation axis (A), and thus overlaps the first bearing surface; A steering system (10) according to at least one of claims 1 to 13.

15. 15. The steering system (10) according to at least one of claims 1 to 14, wherein the torque feedback device (44) is configured to increase a torque feedback level when a minimum distance between the sliding element (56) and one of the two dead end surfaces (60, 62) falls below a preset threshold.

16. A steering system (10) as described in claim 9, wherein the first longitudinal axis (L1) is parallel to the rotation axis (A).