Compliant shaft-rotor coupling for improved end stop exit

Abstract

A steer-by-wire device for controlling a vehicle includes a housing, an input shaft rotatable relative to the housing and configured to receive a rotational input from an operator of the vehicle at a first end of the input shaft, the first end being located outside the housing, a rotor attached to the input shaft at a second end of the input shaft, the second end being located inside the housing and opposite to the first end, a sensor configured to detect an angular position, angular velocity and / or angular acceleration of the input shaft relative to the housing, and a coil for generating a magnetic field to generate a rotational force or torque in the rotor to resist rotation of the rotor. The rotor is attached to the input shaft to allow relative movement between at least a portion of the rotor and the input shaft.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to U.S. Provisional Patent Application Serial No. 62 / 953,655 filed on December 26, 2019, the disclosure of which is incorporated herein by reference in its entirety. Technical Field

[0003] The present invention relates to the fields of brakes, clutches, resistance generating devices and motion control devices. In particular, the present invention relates to devices that use field responsive materials to control torque in rotary motion devices. Background Art

[0004] Steer-by-wire devices and systems operate by transmitting rotational movement of an input device (such as, for example, a steering wheel) to cause corresponding movement of an output device (such as, for example, a pinion in a rack and pinion steering assembly) without the input device being physically connected to the output device. Thus, rotational movement of an input device (such as, for example, an operator rotating a steering wheel) is detected and transmitted to the output device, where a corresponding movement of the output device is executed. Unlike a direct connection (e.g., a mechanical connection) between an input device and an output device, in a steer-by-wire application, the input device is not directly connected to the output device, and therefore, movement of the input device does not result in corresponding movement of the output device without an electronic transmission of a command to the output device.

[0005] Steer-by-wire applications are advantageous in many applications where a direct physical link or series of links connecting an input device to an output device is impractical or impossible, either due to physical separation between the input device and the output device or intervening obstacles, etc. The input device may include, for example, a steering wheel or other suitable input and output shafts that are rigidly connected to the steering wheel to prevent relative movement between the input and output shafts and the steering wheel. Hall effect sensors are typically provided in the input device of such steering systems to provide angular position information to a steering controller that will send a signal to cause a corresponding movement of the output device or a corresponding movement within the output device. A magnet will typically be rigidly attached to the end of the output shaft opposite the steering wheel so as to be sufficiently close to the Hall effect sensor so that the rotational movement of the magnet can be detected by the Hall effect sensor. However, due to the lack of a direct connection between the input device and the output device, there is typically no mechanical restriction to indicate at the input device that the end of travel has been reached at the output device. Therefore, in such steer-by-wire applications, it is typically necessary to introduce an analog end stop.

[0006] A magnetically responsive rotor may be attached to an output shaft of an input device such that rotational movement of the output shaft causes corresponding rotational movement of the rotor having substantially the same angular rotational direction and magnitude. The rotor may be disposed adjacent an electromagnetic coil within the input device that, when current is applied to the coil, produces a torque on the rotor that increases the amount of force that must be applied to the input device to cause further rotational movement of the output shaft and the rotor. The torque produced may be proportional to the amount of current applied to the coil. When an end stop condition has been reached at the output device such that further displacement in a given direction of travel, whether angular, linear, or otherwise, is mechanically impossible, a maximum current is applied to the coil to produce a peak end stop torque on the rotor, and correspondingly, a peak end stop torque on the output shaft to prevent further rotational movement of the input device steering wheel. As is well known, once this peak end stop torque is produced, the torque resists angular movement of the steering wheel in both directions, resulting in what is sometimes referred to as "sticky" steering, in which the steering wheel does not naturally leave the end stop but must be overcome in order to rotate the steering wheel in the opposite direction. This "sticky" steering can make steering more difficult for the driver because the driver is required to overcome the peak end-stop torque in order to rotate the steering wheel in the opposite direction from the end-stop position. Therefore, there is a need for steer-by-wire devices, systems and / or methods that do not exhibit this "sticky" steering behavior. Summary of the invention

[0007] According to the present disclosure, a steer-by-wire device is provided to control a vehicle. In an exemplary embodiment, the steer-by-wire device includes a housing; an input shaft rotatable relative to the housing and configured to receive a rotational input from an operator of the vehicle at a first end of the input shaft, the first end being located outside the housing; a rotor attached to the input shaft at a second end of the input shaft, the second end being located inside the housing and opposite to the first end; a sensor configured to detect an angular position, angular velocity, and / or angular acceleration of the input shaft relative to the housing; and a coil configured to generate a magnetic field when current is supplied to the coil, wherein the magnetic field generates a rotational force or torque in the rotor to resist rotation of the rotor; wherein the rotor is attached to the input shaft to allow relative movement between at least a portion of the rotor and the input shaft.

[0008] In some embodiments of steer-by-wire devices, rotation of the input shaft causes the steering angle of the vehicle to change in a corresponding direction of rotation of the input shaft.

[0009] In some embodiments of steer-by-wire devices, the input shaft is rotatable between specified end stops, each end stop corresponding to a limit of the steering angle of the vehicle.

[0010] In some embodiments of the steer-by-wire device, relative motion occurs between the rotor and the input shaft when the rotational direction of the input shaft changes or reverses.

[0011] In some embodiments, the steer-by-wire device includes pole sets of opposite polarity arranged on opposite sides of the rotor, such as vertical sides.

[0012] In some embodiments of the steer-by-wire device, the rotor includes a magnetically responsive material.

[0013] In some embodiments of the steer-by-wire device, the input shaft is rotatably supported within the housing by one or more bearings coaxially aligned with the rotor.

[0014] In some embodiments, the steer-by-wire device includes at least one magnet rigidly attached to or integrally formed with the input shaft, the magnet being adjacent to the sensor.

[0015] In some embodiments of the steer-by-wire device, the sensor includes a Hall effect sensor configured to detect rotation of the magnet.

[0016] In some embodiments of steer-by-wire devices, a recess [we could change from "hole" to "recess", but "drive feature" would be interpreted unfavorably in the United States] formed in the rotor is larger in size than the portion of the input shaft that is inserted into the recess.

[0017] In some embodiments of the steer-by-wire device, when the input shaft rotates in a first direction, the input shaft contacts the inner surface of a recess formed in the rotor at one or more first contact points; when the input shaft rotates in a second direction opposite to the first direction, the input shaft contacts the inner surface of the recess formed in the rotor at one or more second contact points; after the input shaft changes the rotation direction from the first direction to the second direction, before the input shaft contacts the second contact point to rotate the rotor in the second direction, the input shaft is spaced apart from the first contact point and the second contact point for a period of time; and after the input shaft changes the rotation direction from the second direction to the first direction, before the input shaft contacts the first contact point to rotate the rotor in the first direction, the input shaft is spaced apart from the first contact point and the second contact point for a period of time.

[0018] In some embodiments of the steer-by-wire device, the input shaft and the recess of the rotor include a triple drive device, so that there are three first contact points and three second contact points. Any number of contact points can be used to react the torque of the device as desired.

[0019] In some embodiments of the steer-by-wire device, the first contact point and the second contact point are a first contact plane and a second contact plane, respectively.

[0020] In some embodiments of the steer-by-wire device, the input shaft and the recessed portion of the rotor include a square drive arrangement, thereby having four first contact points and four second contact points.

[0021] In some embodiments of the steer-by-wire device, the rotor includes an inner portion and an outer portion, wherein the inner portion is rotatable relative to the outer portion.

[0022] In some embodiments of a steer-by-wire device, the interior is connected to the exterior by a plurality of radially oriented ribs extending between the interior and the exterior, each rib being arranged in a corresponding channel radially formed in the exterior, such that each rib has a first end connected to the interior and a second end connected to the exterior opposite to the first end, and each rib is spaced apart from the exterior along the length of each corresponding channel.

[0023] In some embodiments of the steer-by-wire device, the ribs are flexible in the direction of rotation of the input shaft to allow relative rotational movement of the inner portion with respect to the outer portion.

[0024] In some embodiments of the wire-controlled steer device, the outer portion includes a plurality of grooves formed in an inner radial surface of the outer portion and circumferentially spaced around the inner radial surface; the inner portion includes a plurality of radially protruding stops, each stop being located within a corresponding one of the plurality of grooves formed in the outer portion; and the gap between the stop and the groove in the rotational direction of the input shaft is smaller than the gap defined between the rib and the outer portion, so that during operation of the wire-controlled steer device, the rib does not contact the outer portion except at the second end.

[0025] In some embodiments of the steer-by-wire device, the pole piece includes metal so that magnetic flux can flow from the coil through the pole piece.

[0026] In some embodiments of the steer-by-wire device, the pole piece is constructed of metal so that magnetic flux can flow from the coil through the pole piece.

[0027] In some embodiments of a steer-by-wire device, a rotor includes an inner portion and an outer portion; the outer portion includes a cavity defining an inner circumference of the outer portion; the inner portion is disposed within the cavity of the outer portion; and the inner portion is flexibly connected to the outer portion so that the inner portion can rotate within a first angular range of movement of the rotor without causing corresponding rotational movement of the outer portion within the first angular range, wherein the first angular range is less than a total angular range of movement of the rotor between specified end stops, each end stop corresponding to a limit of a steering angle of the vehicle.

[0028] In some embodiments of the wire-controlled steer device, the inner part has an oval or elliptical outer periphery, and the outer part has an oval or elliptical inner periphery, and the oval or elliptical shape of the inner outer periphery is smaller than the oval or elliptical shape of the inner periphery of the outer part to define a circumferential gap between the inner part and the outer part, and the gap defines a first range of motion angles.

[0029] In some embodiments, the steer-by-wire device includes a gasket disposed continuously around and within a gap between the inner portion and the outer portion, the gasket including a compliant material.

[0030] In some embodiments of the steer-by-wire device, the compliant material includes a compressible viscoelastic material.

[0031] In some embodiments of the wire-controlled steer device, the outer portion includes a ring extending radially inward from the inner periphery of the outer portion; and the inner portion includes a first inner portion and a second inner portion, the first inner portion and the second inner portion having a circumferential recess formed therein, and when the first inner portion and the second inner portion are assembled together in the cavity of the outer portion, the outer ring is arranged in the recess.

[0032] In some embodiments, the steer-by-wire device includes a washer arranged in a circumferential recess defined by an inner portion so that the inner portion does not contact the outer portion when the rotor rotates within an angular range between specified end stops, each end stop corresponding to a limit of the steering angle of the vehicle.

[0033] In some embodiments of the steer-by-wire device, the washer includes a compliant material.

[0034] In some embodiments of the steer-by-wire device, the compliant material includes a compressible viscoelastic material.

[0035] In some embodiments of the steer-by-wire device, the first inner portion and the second inner portion are fixed together to rotate in unison within the cavity of the outer portion.

[0036] These and other embodiments are described in greater detail in the detailed description that follows. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 is a side cross-sectional view of a first example embodiment of a steer-by-wire device.

[0038] Figure 2 yes Figure 1 The steer-by-wire device Figure 1 A top cross-sectional view taken along section 2-2 is shown.

[0039] Figure 3A yes Figure 1 A partial top cross-sectional view of a steer-by-wire device, wherein the input shaft rotates in a first direction relative to the rotor.

[0040] Figure 3B yes Figure 1 A partial top cross-sectional view of a steer-by-wire device, wherein the input shaft rotates in a second direction relative to the rotor, the second direction being opposite to the first direction.

[0041] Figure 4 is a partial top cross-sectional view of a second example embodiment of a steer-by-wire device.

[0042] Figure 5A yes Figure 4 A partial top cross-sectional view of a steer-by-wire device, wherein the input shaft rotates in a first direction.

[0043] Figure 5B yes Figure 4 A partial top cross-sectional view of a steer-by-wire device, wherein the input shaft rotates in a second direction relative to the rotor, the second direction being opposite to the first direction.

[0044] Figure 6 is a top view of an example embodiment of a rotatable flexible rotor suitable for use in a steer-by-wire device.

[0045] Figure 7 yes Figure 6 A top view of a rotatable flexible rotor wherein the inner portion of the rotatable flexible rotor rotates relative to the outer portion.

[0046] Figure 8 is a top view of an example embodiment of a rotatable flexible rotor suitable for use in a steer-by-wire device.

[0047] Fig. 9 yes Figure 8 A cross-sectional view of a rotatable flexible rotor. DETAILED DESCRIPTION

[0048] It should be understood that the steer-by-wire devices, features, and methods described herein are not limited to the specific embodiments presented in the detailed description and drawings. It should be recognized that these embodiments are merely illustrative of the principles of the subject matter. Many modifications and adaptations will be apparent to those skilled in the art without departing from the subject matter disclosed herein.

[0049] Now referring to the accompanying drawings, Figure 11 is a cross-sectional view of an example embodiment of a steer-by-wire device, generally designated 100. The steer-by-wire device 100 has an input shaft 120 extending through an opening formed in a housing 110. The input shaft 120 is radially supported within the opening of the housing 110 by one or more bearings 130, which may be any suitable type of bearing, including, for example, ball bearings, roller bearings, journal bearings, etc. In the illustrated embodiment, a plurality of bearings 130 are shown. The input shaft 120 extends within the housing 110, beyond the bearings 130, and is attached to a rotor 140 at a proximal end of the input shaft 120, such that when a rotational input is transmitted to the input shaft 120 at a distal end of the input shaft 120, the input shaft 120 and the rotor 140 rotate at substantially the same angular velocity. The proximal and distal ends of the input shaft 120 are opposite ends of the input shaft 120. The input shaft 120 is configured to receive an input, such as a rotational force or rotational motion, at a distal end of the input shaft 120 and transfer the rotational force or rotational motion to the rotor 140 at a proximal end of the input shaft 120 .

[0050] The magnet is rigidly attached to the proximal end of the input shaft 120 such that the magnet is concealed within the housing 110. In some embodiments, the magnet is integrally formed as part of the input shaft 120 and / or as an integral part of a fastener that assembles the input shaft to another structure of the steer-by-wire device 100. A sensor, generally designated 170, is provided to monitor and / or determine the rotational movement of the proximal end of the input shaft 120 and / or the rotor 140. In the illustrated embodiment, the sensor 170 is a Hall effect sensor configured to detect the angular position, angular velocity, and / or angular acceleration of the magnet attached to the input shaft 120 as the input shaft 120 rotates within the housing 110. Advantageously, the attachment of the magnet to the input shaft 120 is rigid, allowing no or only negligible relative movement between the magnet and the input shaft 120 during operation of the steer-by-wire device 100. In this manner, the angular position of the input shaft can be determined with sufficient accuracy and / or precision to transmit a precise steering angle to a vehicle or other suitable device controlled by the steer-by-wire device 100. When the angular position of the input shaft 120 changes, and thus the angular position of the magnet changes, the steering angle of the vehicle changes accordingly in a linear or non-linear relationship.

[0051] The steer-by-wire device 100 has an electric motor including a pole assembly 180. The pole assembly 180 includes a coil 150, which is secured within a housing 110 by an axially oriented fastener 190 (e.g., a pin) that extends through the entire pole assembly 180 and into a recess formed in the housing 110 such that the pole assembly 180 cannot rotate within the housing 110, as shown in FIG. Figure 1 and Figure 2In addition, the pole assembly 180 has a keyed recess 182 into which the key 152 of the coil 150 is inserted during assembly of the steer-by-wire device 100 to rotationally lock the coil 150 and the pole assembly 180 together with the housing 110 via the fastener 190. The rotor 140 is radially spaced from the coil 150 such that the rotor 140 does not physically contact the coil 150 within the housing 110. The provision of a plurality of bearings 130 along the length of the input shaft 120 helps ensure that the input shaft 120 cannot deflect radially within the housing 110, which would otherwise result in contact between the rotor 140 and the coil 150.

[0052] When current is applied to the coil 150, a magnetic field is generated to generate a rotational force or torque on the rotor 140, which at least partially includes a ferromagnetic material. The strength of the magnetic field and the rotational force or torque acting on the rotor is proportional to the current supplied to the coil 150. The rotor 140 can rotate within a predetermined range of angular positions, which is defined between specified rotational end points corresponding to the maximum and / or minimum steering angles of the vehicle. The maximum steering angle and the minimum steering angle can have the same or different magnitudes in opposite directions relative to a "zero" position, such as a position where the vehicle will move in a straight line. When the sensor 170 detects through a magnet that the input shaft 120 has rotated to or beyond any specified rotational end point of the predetermined angular position range, the maximum current is applied to the coil 150 to generate a maximum magnetic field, and accordingly, a maximum rotational force or torque is generated on the rotor 140 to prevent further rotational movement of the input shaft in the direction of the rotational end point. This application of maximum rotational force or torque on the rotor 140 prevents the input shaft from rotating to an angular position corresponding to a steering angle that exceeds the maximum or minimum steering angle that the controlled vehicle is capable of achieving, thereby acting in the manner of an end stop of a conventional steering device in which a mechanical stop would prevent further rotational movement of the input shaft. Advantageously, the current supplied to the coil 150 is of sufficient magnitude to prevent the operator from further rotating the input shaft beyond the specified rotational end point.

[0053] In some embodiments, no current is supplied to coil 150 throughout the predetermined range of angular positions, except at specified rotational endpoints, such that input shaft 120 rotates freely (e.g., without rotational force or torque) throughout the predetermined range of angular positions, except at specified rotational endpoints corresponding to maximum and / or minimum steering angles of the vehicle.

[0054] In some embodiments, when the sensor 170 detects a magnet attached to the input shaft 120 at any angular position other than the "zero" position, current is supplied to the coil 150. Thus, when the input shaft 120 and the magnet are detected to be in any angular position other than the "zero" position, a rotational force or torque is applied to the rotor 140. In some such embodiments, the applied current is a variable current, meaning that the magnitude of the current is not constant, but varies based on the angular position of the input shaft 120 detected by the sensor 170 through the magnet. It is advantageous for the magnitude of the current to increase continuously or in a stepwise manner as the input shaft 120 rotates away from the "zero" position. Since the rotational force or torque delivered to the rotor 140 increases as the input shaft 120 rotates away from the "zero" position, the relative angular position of the input shaft 120 within a predetermined range of angular positions, and the corresponding steering angle of the vehicle, can be sensed by the operator based on the magnitude of the input force that must be generated by the operator to rotate the shaft, thereby providing tactile feedback to the operator of the steer-by-wire device 100. In some embodiments, current may be supplied to the coil 150 even when the input shaft 120 is in the "zero" position, so that a rotational force or torque will be applied to the rotor when the input shaft 120 is in the "zero" position. In such embodiments, the current supplied to the coil 150 increases, for example, in a linear or non-linear manner, as the input shaft 120 moves away from the "zero" position in either angular direction. In some embodiments, the relationship between the magnitude of the current supplied to the coil 150 and the angular position of the input shaft 120 is linear over the entire predetermined range of angular positions, with a step from an intermediate current value less than the maximum current to a maximum current that occurs when the input shaft 120 is detected to be at any specified rotational endpoint of the predetermined range of angular positions.

[0055] In order to prevent the rotor 140 from being held at any given end of rotation by a maximum rotational force and / or torque that an operator must overcome to rotate the input shaft away from the given end of rotation and toward the "zero" position, a flexible coupling region, generally designated 160, is defined at the junction of the input shaft 120 and the rotor 140. Figures 2 to 3B1. A first example embodiment of a flexible coupling region 160 is shown in FIG. According to this first example embodiment, the input shaft 120 has a three-drive configuration, wherein the input shaft 120 has three radially extending protrusions 122 that engage in three corresponding slots 142 formed in the inner circumferential surface of the rotor 140. The protrusions 122 and the slots 142 may have any suitable size, number, and spacing around the input shaft 120 based on the rotational forces and / or torques that must be reacted at the flexible coupling region 160. Thus, while three protrusions 122 and three slots 142 are shown in the example embodiment, any number of protrusions 122 and slots 142 may be provided. In order for each protrusion 122 to fit within a corresponding one of the slots 142, the size of each protrusion 122 is smaller than the size of the slot 142 with which the protrusion 122 will engage. In some embodiments, the size of one or more protrusions 122 and slots 142 may be different from the size of the other protrusions 122 and slots 142. In some embodiments, the size of each protrusion 122 and slot 142 may be different from the size of each other protrusion 122 and slot 142, such that the size of each pair of protrusions 122 and slots 142 may be different from the size of each other pair of protrusions 122 and slots 142. A radial gap, generally indicated at 162, is provided between the input shaft 120 and the rotor 140 to allow relative rotational movement between the input shaft 120 and the rotor 140 when the rotational direction of the input shaft 120 is reversed, such as from clockwise to counterclockwise or from counterclockwise to clockwise. In some embodiments, the radial gap 162 need not be maintained around the entire circumference of the input shaft 120 during operation of the steer-by-wire device 100.

[0056] Each pair of protrusions 122 and slots 142 also has a circumferential gap (generally designated 164) to allow relative rotational movement between the input shaft 120 and the rotor 140 when the input shaft changes rotational direction as described elsewhere herein. Each protrusion 122 has a first contact surface 124 and a second contact surface 126, which are located on opposite sides along the circumferential direction of the input shaft 120 and / or the rotor 140. Each slot has a first contact surface 144 and a second contact surface 146, which are located on opposite sides along the circumferential direction of the input shaft 120 and / or the rotor 140. As shown in FIG. Figure 3A As shown, when the input shaft 120 rotates in a first direction (e.g., clockwise), the input shaft 120 rotates relative to the rotor 140, so that the first contact surfaces 124, 144 of one or more (e.g., all) of the protrusions 122 and the grooves 142 contact each other, causing the input shaft 120 and the rotor 140 to rotate together. In other words, the rotational movement of the input shaft 120 will cause the rotor 140 to rotate with a substantially similar amplitude. Therefore, as shown in FIG. Figure 3AAs shown, when the input shaft 120 rotates in the first direction, a circumferential gap 164 exists between the second contact surfaces 126 , 146 of the protrusion 122 and the groove 142 , while the first contact surfaces 124 , 144 of the protrusion 122 and the groove 142 directly contact each other.

[0057] When the sensor 170 detects that the angular position of the input shaft 120 and, accordingly, the rotor 140 is at or beyond the end stop in the first direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft 120 and the rotor 140 in the first direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 140 to prevent rotational movement of the rotor 140 in the first or second direction, resulting in "sticky" steering. In conventional steer-by-wire devices, this means that the operator must overcome the rotational force and / or torque, even to be able to rotate the input shaft 120 in the opposite direction. However, according to the presently disclosed subject matter, because there is a circumferential gap 164 between the second contact surfaces 126, 146 in the second direction, the input shaft 120 can be rotated in the second direction by an amount corresponding to the size of the circumferential gap 164, thereby allowing the input shaft 120 to rotate in the second direction even when the rotor 140 is held in place by the rotational force and / or torque. In some embodiments, the rotation of the input shaft 120 may be, for example, between 0.5 and 2 degrees without a corresponding rotation of the rotor 140. The sensor 170 is capable of detecting this rotation of the input shaft 120 in the second direction without a corresponding rotation of the rotor 140, thereby causing the maximum current supplied to the coil 150 to terminate after the input shaft 120 contacts the rotor 140 at the second contact surfaces 126, 146 of the protrusion 122 and the slot 142, and allowing the rotor 140 to rotate in the second direction. Advantageously, the circumferential gap 164 is large enough to allow the sensor 170 to detect the angular rotation of the input shaft 120 relative to the rotor 140 before the input shaft 120 contacts the rotor 140 at the second contact surfaces 126, 146 of the protrusion 122 and the slot 142, so that the maximum current can be terminated without the operator having to overcome the maximum rotational force and / or torque to rotate the input shaft 120 in the second direction away from the first end stop.

[0058] Similarly, if Figure 3BAs shown, when the input shaft 120 rotates in the second direction (e.g., counterclockwise), the input shaft 120 rotates relative to the rotor 140 so that the first contact surfaces 124, 144 of one or more (e.g., all) of the protrusions 122 and the slots 142 contact each other, causing the input shaft 120 and the rotor 140 to rotate together with each other. When the sensor 170 detects the angular position of the input shaft 120 and, accordingly, the rotor 140 is at or beyond the end stop in the second direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft 120 and the rotor 140 in the second direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 140 to prevent rotational movement of the rotor 140 in the first direction or the second direction, resulting in "sticky" steering. As shown in FIG. Figure 3B As shown, due to the presence of the circumferential gap 164 between the first contact surfaces 124, 144 in the first direction, the input shaft 120 can be rotated in the first direction by an amount corresponding to the size of the circumferential gap 164, thereby allowing the input shaft 120 to rotate in the first direction even when the rotor 140 is held in place by a rotational force and / or torque. The sensor 170 is capable of detecting this rotation of the input shaft 120 in the first direction without requiring a corresponding rotation of the rotor 140, thereby causing the maximum current supplied to the coil 150 to terminate after the input shaft 120 contacts the rotor 140 at the first contact surfaces 124, 144 of the protrusion 122 and the slot 142, and allowing the rotor 140 to rotate in the first direction. As described elsewhere herein, advantageously, the circumferential gap 164 is large enough to allow the sensor 170 to detect angular rotation of the input shaft 120 relative to the rotor 140 before the input shaft 120 contacts the rotor 140 at the first contact surfaces 124, 144 of the protrusion 122 and the slot 142, so that maximum current flow can be terminated without the operator having to overcome maximum rotational force and / or torque to rotate the input shaft 120 in the first direction away from the second end stop. The rotor 140 floats axially to allow the input shaft 120 to rotate freely, resulting in a small amount of zero torque rotation, thereby allowing the operator to rotate the input shaft 120 without having to overcome the rotational force and / or torque applied when the input shaft 120 is rotated to one of the end stops. In some embodiments, an axial load may be applied to the rotor to minimize the operator's perception of zero torque rotation.

[0059] Figures 4 to 5BA second example embodiment of a flexible coupling region (generally indicated at 220) between the input shaft 200 and the rotor 210 of the second example embodiment is shown. According to this second example embodiment, the input shaft 200 and the rotor 210 are coupled together in a square drive configuration. As such, the portion of the input shaft 200 that engages the rotor 210 has a generally square cross-section, and the recess formed in the rotor 210 with which the input shaft 200 engages has a generally square cross-section. In order to allow relative movement between the input shaft 200 and the rotor 210, the recess of the rotor 210 is larger in size than that of the input shaft 200, thereby allowing angular movement of the input shaft 200 relative to the rotor 210.

[0060] like Figure 5A As shown, when the input shaft 200 rotates in a first direction (e.g., clockwise), the input shaft 200 rotates within the recess of the rotor 210, causing the contact surface 202 of the input shaft 200 to rotate to contact an adjacent one of the contact surfaces 212 of the recess of the rotor 210, such as an inner circumferential surface, at a first contact point (generally indicated as 222), while there is a gap 224. In the illustrated embodiment, the recess is in the form of a square hole. Thus, the first contact point 222 and the gap 224 are located at opposite ends of each of the contact surfaces 202, 212 of the input shaft 200 and the rotor 210. When the input shaft 200 rotates in the first direction, the input shaft 200 rotates relative to the rotor 210, causing the contact surfaces 202, 212 of the input shaft 200 and the rotor 210 to contact each other at the first contact point 222, causing the input shaft 200 and the rotor 210 to rotate together with each other. In other words, the rotational movement of the input shaft 200 will cause the rotor 210 to rotate with a substantially similar amplitude. Therefore, if Figure 5A As shown, when the input shaft 200 rotates in the first direction, a gap 224 exists at an end of the contact surfaces 202 , 212 opposite to the corresponding first contact point where the contact surfaces 202 , 212 directly contact each other.

[0061] When the sensor 170 detects that the angular position of the input shaft 200 and the corresponding rotor 210 is at or beyond the end stop in the first direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft 200 and the rotor 210 in the first direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 210 to prevent rotational movement of the rotor 210 in the first direction or the second direction, resulting in "sticky" steering. In conventional steer-by-wire devices, this means that the operator must overcome the rotational force and / or torque to even be able to rotate the input shaft 200 in the opposite direction. However, according to the presently disclosed subject matter, since there is a gap 224 between the contact surfaces 202, 212 at the opposite ends of the contact surfaces 202, 212 opposite the first contact point in the second direction (e.g., counterclockwise), the input shaft 200 can be rotated in the second direction by an amount corresponding to the size of the gap 224, thereby allowing the input shaft 200 to rotate in the second direction even when the rotor 210 is held in place by the rotational force and / or the rotational force. In some embodiments, the rotation of the input shaft 200 can be, for example, between 0.5 degrees and 2 degrees without a corresponding rotation of the rotor 210. The sensor 170 is capable of detecting such rotation of the input shaft 200 in the second direction without requiring a corresponding rotation of the rotor 210, causing the maximum current supplied to the coil 150 to terminate after the input shaft 200 contacts the rotor 210 at the second contact point (generally represented by 226) of the contact surfaces 202, 212 of the input shaft 200 and the rotor 210, respectively, and allowing the rotor 210 to rotate in the second direction. It should be noted that when the contact surfaces 202, 212 contact each other at the second contact point 226, another gap (generally indicated at 228) exists at the opposite end of the contact surfaces 202, 212 where the first contact point 222 is located when the input shaft rotates in the first direction. Advantageously, the gaps 224, 228 are large enough to allow the angular rotation of the input shaft 200 relative to the rotor 210 to be detected by the sensor 170 before the input shaft 200 contacts the rotor 210 at the second contact point 226, so that the maximum current flow can be terminated without the operator having to overcome the maximum rotational force and / or torque to rotate the input shaft 200 in the second direction away from the first end stop.

[0062] Similarly, if Figure 5BAs shown, when the input shaft 200 rotates in the second direction, for example, in the counterclockwise direction, the input shaft 200 rotates relative to the rotor 210 so that the contact surfaces 202, 212 of the input shaft 200 and the rotor 210 contact each other at the second contact point 226, causing the input shaft 200 and the rotor 210 to rotate together with each other. When the contact surfaces 202, 212 contact each other at the second contact point 226, there is a gap 228 at the opposite ends of the contact surfaces 202, 212. When the sensor 170 detects the angular position of the input shaft 200 and, accordingly, the rotor 210 is at or beyond the end stop in the second direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft 200 and the rotor 210 in the second direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 210 to prevent rotational movement of the rotor 210 in the first direction or the second direction, resulting in "sticky" steering. As shown in FIG. Figure 5B As shown, due to the presence of the gap 228 between the contact surfaces 202, 212 in the first direction, the input shaft 200 can be rotated in the first direction by an amount corresponding to the size of the gap 228, thereby allowing the input shaft 200 to rotate in the first direction even when the rotor 210 is held in place by a rotational force and / or torque. The sensor 170 is capable of detecting such rotation of the input shaft 200 in the first direction without requiring a corresponding rotation of the rotor 210, which results in the termination of the maximum current supplied to the coil 150 and allows the rotor 210 to rotate in the first direction after the input shaft 200 contacts the rotor 210 at the first contact point 222 (see Figure 5A As described elsewhere herein, advantageously, gap 228 is large enough to allow angular rotation of input shaft 200 relative to rotor 210 to be detected by sensor 170 before input shaft 200 contacts rotor 210 at first contact point 222, such that maximum current flow can be terminated without an operator having to overcome a maximum rotational force and / or torque to rotate input shaft 200 in the first direction away from the second end stop.

[0063] Figures 4 to 5B The operation of the illustrated example embodiment is otherwise substantially similar to Figures 2 to 3B Example embodiments shown.

[0064] Figure 6 and Figure 7 An exemplary embodiment of a rotor, generally designated 240, is shown which is suitable for use in Figure 1The invention discloses a steer-by-wire device 100. According to this embodiment, the rotor 240 includes an inner portion 260, which is radially located within the outer portion 250. In this way, the outer portion 250 surrounds the inner portion 260. The input shaft passes through the recess 270 and is rigidly coupled and / or attached to the inner portion 260 so that relative angular movement between the input shaft and the inner portion 260 is prevented by the input shaft lockingly engaging with the keyed recess 272 formed in the inner portion 260. The inner portion 260 is connected to the outer portion 250 by a plurality of ribs 264, which extend in a radial direction away from the inner portion 260. Five ribs 264 are provided in the rotor 240 of the example embodiment shown, but any number of ribs 264 may be provided. The ribs 264 are connected to the inner portion 260 at a first end of the rib and are connected to the outer portion 250 at a second end of the rib, such as a connection point (generally labeled 270). Each rib is disposed within a channel radially formed in the outer portion, thereby defining a gap 254 on either side of each rib 264, allowing relative angular movement of the inner portion 260 relative to the outer portion 250. In some embodiments, it is advantageous that the gap 254 is large enough so that during normal operation of the steer-by-wire device, the rib 264 does not contact the outer portion 260 except at the corresponding connection point 270. The rib 264 is flexible in a rotational direction, such as in a plane defined by the rotor 240 and / or the input shaft, to allow relative angular movement and / or displacement of the inner portion 260 relative to the outer portion 250. The outer portion 250 includes a plurality of grooves 252 formed in an inner radial surface of the outer portion 250 and circumferentially spaced about the inner radial surface. The inner portion 260 includes a plurality of radially protruding stops 262, each stop 262 disposed and / or positioned within a respective one of the plurality of grooves 252 formed in the outer portion 250. The size of the stopper 262 in the circumferential direction is smaller than the size of the groove 252, thereby defining a circumferential gap between the stopper 262 and the groove 252 and allowing angular movement of the inner portion 260 relative to the inner portion 250. The size of the gap between the stopper 262 and the groove 252 defines the maximum angular deflection of the inner portion 260 relative to the outer portion 250. Thus, when the inner portion 260 has rotated a maximum specified angle relative to the outer portion 250, the stopper 262 contacts the circumferential edge of the groove 252 to prevent the inner portion 260 from further rotating relative to the outer portion 250. Advantageously, the gap between the stopper 262 and the groove 252 is smaller than the gap 254 separating the rib 264 from the outer portion 250 to prevent the rib 264 from contacting the outer portion 250 beyond the connection point 270.

[0065] During normal operation, such as between the end stops, the input shaft and rotor 240 rotate together with one another such that rotational movement of the input shaft will result in rotational movement of the rotor 240 having a substantially similar amplitude.

[0066] When the sensor detects that the angular position of the input shaft and, accordingly, the rotor 240 is at or beyond the end stop in the first direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft and the rotor 240 in the first direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 240 to prevent rotational movement of the rotor 240 in the first direction or the second direction, resulting in "sticky" steering. As described elsewhere herein, in conventional steer-by-wire devices, this means that the operator must overcome the rotational force and / or torque, even to be able to rotate the input shaft in the opposite direction. However, according to the presently disclosed subject matter, due to the presence of the rib 264 connecting the inner portion 260 to the outer portion 250, the input shaft and the inner portion 250 can be rotated relative to the outer portion 250 in the second direction by an amount corresponding to the size of the circumferential gap between the stop 262 and the slot 252 in the second direction, thereby allowing the input shaft and the inner portion 260 to rotate in the second direction even when the outer portion 260 of the rotor 240 is held in place by the rotational force and / or torque. In some embodiments, the rotation of the input shaft and the inner portion 260 may be, for example, between 0.5 and 2 degrees without corresponding rotation of the outer portion 260 of the rotor 240. The sensor is able to detect the rotation of the input shaft and the inner portion 260 in the second direction without corresponding rotation of the outer portion 250 of the rotor 240 in the second direction, which results in termination of the maximum current supplied to the coil 150 and allows the entire rotor 240 to rotate in the second direction after the input shaft has rotated an angular amount sufficient to be detected by the sensor. Advantageously, the gaps between the stop 262 and the slot 252 and between the rib 264 and the outer portion 260 are large enough to allow the angular rotation of the input shaft and the inner portion 260 relative to the outer portion 250 of the rotor 240 to be detected by the sensor before the stop 262 contacts the outer portion 250 within the slot 252, thereby terminating the maximum current without the operator having to overcome the maximum rotational force and / or torque to rotate the input shaft away from the first end stop in the second direction. Figure 7 2 is an exemplary illustration of the inner portion 260 rotating relative to the outer portion 250 , wherein the stopper 262 is in contact with the groove 252 , and the rib 264 is elastically deformed in the circumferential direction.

[0067] When the sensor 170 detects that the angular position of the input shaft and, accordingly, the rotor 240 is at or beyond the end stop in the second direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft and the rotor 210 in the second direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the rotor 240 to prevent rotational movement of the rotor 240 in the first direction or the second direction, resulting in a "sticky" turn. According to the presently disclosed subject matter, due to the presence of the rib 264 connecting the inner portion 260 to the outer portion 250, the input shaft and the inner portion 250 can be rotated relative to the outer portion 250 in the first direction by an amount corresponding to the size of the circumferential gap between the stop 262 and the slot 252 in the first direction, thereby allowing the input shaft and the inner portion 260 to rotate in the first direction even when the outer portion 260 of the rotor 240 is held in place by the rotational force and / or torque. In some embodiments, the rotation of the input shaft and the inner portion 260 may be, for example, between 0.5 and 2 degrees without corresponding rotation of the outer portion 260 of the rotor 240. The sensor is able to detect such rotation of the input shaft and the inner portion 260 in the first direction without corresponding rotation of the outer portion 250 of the rotor 210 in the first direction, which results in termination of the maximum current supplied to the coil 150 and allows the entire rotor 240 to rotate in the second direction after the input shaft has rotated an angular amount sufficient to be detected by the sensor. Advantageously, the gaps between the stop 262 and the slot 252 and between the rib 264 and the outer portion 260 are large enough to allow the angular rotation of the input shaft and the inner portion 260 relative to the outer portion 250 of the rotor 240 to be detected by the sensor before the stop 262 contacts the outer portion 250 within the slot 252, thereby terminating the maximum current without the operator having to overcome the maximum rotational force and / or torque to rotate the input shaft in the first direction away from the second end stop.

[0068] Reference now Figure 8 and Fig. 9 , shows an example embodiment of a rotor, generally indicated at 280, which is suitable for Figure 1The invention relates to a steer-by-wire device 100. According to this embodiment, the rotor 280 includes an inner portion 320, which is radially located inside the outer portion 300. In this way, the outer portion 300 surrounds the inner portion 320. The input shaft passes through the recess 350 and is rigidly coupled and / or attached to the inner portion 320, so that relative angular movement between the input shaft and the inner portion 320 is prevented by, for example, lockingly attaching to the inner portion 320. The inner portion 320 is connected to and spaced apart from the outer portion 300 by an annular gasket 330, which defines a gap 340 between the inner portion 320 and the outer portion 300. It is advantageous for the gasket 330 to be a viscoelastic material that can be compressed when the inner portion 320 rotates relative to the outer portion 300, so that the inner portion 320 can rotate relative to the outer portion 300 when the outer portion 300 remains stationary at the end of its travel corresponding to the maximum steering input allowed by the steer-by-wire device on which the rotor 280 is installed.

[0069] In some embodiments, the gap 340 is selected to allow a predetermined amount of relative movement between the inner portion 320 and the outer portion 300 before the inner portion 320 will contact the outer portion 300 to prevent further relative rotational movement therebetween. In some embodiments, the washer 330 has a hardness sufficiently hard so that the inner portion 320 and the outer portion 300 cannot directly contact each other during normal operation. In the illustrated embodiment, the inner portion 320 includes a first half 322 and a second half 324 assembled together at an interface edge 326. The first half 322 and the second half 324 have a recessed portion that, when assembled, forms a recess 328 in which the washer 330 is located when the rotor 280 is assembled. The outer portion 300 includes an inner annular ring disposed within the recess 328 so that the washer 330 can engage the inner ring when the inner portion 320 rotates relative to the outer portion 300. During normal operation, such as between end stops, the outer portion 300 and the inner portion 320 rotate together such that rotational movement of the inner portion 320 will result in rotational movement of the outer portion 300 having a substantially similar amplitude.

[0070] When the sensor detects that the angular position of the input shaft, the inner portion 320, and / or the outer portion 300 is at or beyond the end stop in the first direction, a maximum current is supplied to the coil 150 to generate a maximum rotational force or torque, thereby preventing the operator from further rotating the input shaft and, accordingly, the inner portion 320 and the outer portion 300 in the first direction. When this maximum current is supplied to the coil 150, a rotational force and / or torque acts on the outer portion 300 of the rotor 240 to prevent rotational movement of the outer portion 300 in the first or second direction, resulting in "sticky" steering. As described elsewhere herein, in conventional steer-by-wire devices, this means that the operator must overcome the rotational force and / or torque to even be able to rotate the input shaft in the opposite direction. However, according to the presently disclosed subject matter, due to the presence of the washer 330 and the gap 340 separating the inner portion 320 from the outer portion 300, the input shaft and the inner portion 320 can rotate relative to the outer portion 300 in the second direction by an amount corresponding to the size of the gap 340 and / or the washer 330 in the second direction, thereby allowing the input shaft and the inner portion 320 to rotate in the second direction even when the outer portion 300 of the rotor 280 is held in place by a rotational force and / or torque. In some embodiments, the rotation of the input shaft and the inner portion 320 can be, for example, between 0.5 degrees and 2 degrees without a corresponding rotation of the outer portion 300 of the rotor 280. The sensor is able to detect the rotation of the input shaft and the inner portion 320 in the second direction without requiring a corresponding rotation of the outer portion 300 of the rotor 280 in the second direction, which results in the termination of the maximum current supplied to the coil 150 and allows the entire rotor 280, such as the inner portion 320 and the outer portion 300, to rotate in the second direction after the input shaft has rotated an angular amount sufficient to be detected by the sensor. Advantageously, the gap 340 is large enough to allow angular rotation of the input shaft and the inner portion 320 relative to the outer portion 300 of the rotor 280 to be detected by the outer circumferential surface of the inner portion 320 from contacting the inner circumferential surface of the outer portion 300, thereby terminating maximum current flow without the operator having to overcome maximum rotational force and / or torque to rotate the input shaft in a second direction away from the first end stop.

[0071] Other embodiments of the rotationally flexible rotor are contemplated, including the use of an elastic member between the inner port and the outer portion, which would allow the inner portion to rotate a predetermined amount due to the elastic properties of the elastic member while the outer portion is held in place by the rotational forces and / or torque generated by the coil.

[0072] Other embodiments of the present subject matter will be apparent to those skilled in the art from consideration of the specification or practice of the subject matter disclosed herein. Accordingly, the foregoing description is considered merely as exemplary of the present subject matter, with the true scope being defined by the appended claims.

Claims

1. A steer-by-wire device for controlling a vehicle, the steer-by-wire device comprising: case; an input shaft rotatable relative to the housing and configured to receive a rotational input from an operator of the vehicle at a first end of the input shaft, the first end being located external to the housing; a rotor attached to the input shaft at a second end of the input shaft, the second end being located within the housing and opposite the first end; a sensor configured to detect an angular position, an angular velocity, and / or an angular acceleration of the input shaft relative to the housing; a coil configured to generate a magnetic field when current is supplied to the coil, wherein the magnetic field generates a rotational force or torque in the rotor to resist rotation of the rotor; as well as at least two pole groups, the at least two pole groups being arranged on opposite sides of the rotor; wherein the rotor is attached to the input shaft to allow relative movement between at least a portion of the rotor and the input shaft; wherein the recess formed in the rotor is larger in size than a portion of the input shaft inserted into the recess; wherein when the input shaft rotates in a first direction, the input shaft contacts an inner surface of the recess formed in the rotor at one or more first contact points; wherein when the input shaft rotates in a second direction opposite to the first direction, the input shaft contacts an inner surface of the recess formed in the rotor at one or more second contact points; wherein, after the input shaft changes the rotation direction from the first direction to the second direction, the input shaft is spaced apart from the first contact point and the second contact point for a period of time before the input shaft contacts the second contact point to rotate the rotor in the second direction; and wherein, after the input shaft changes the rotation direction from the second direction to the first direction, the input shaft is spaced apart from the first contact point and the second contact point for a period of time before the input shaft contacts the first contact point to rotate the rotor in the first direction.

2. The steer-by-wire device according to claim 1, wherein: Rotation of the input shaft causes the steering angle of the vehicle to change in a corresponding direction of rotation of the input shaft.

3. The steer-by-wire device according to claim 2, wherein: The input shaft is rotatable between specified end stops, each of the end stops corresponding to a limit of the steering angle of the vehicle.

4. The steer-by-wire device according to claim 1, wherein: When the rotation direction of the input shaft changes or reverses, relative motion occurs between the rotor and the input shaft.

5. The steer-by-wire device according to claim 1, wherein: The rotor includes a magnetically responsive material.

6. The steer-by-wire device according to claim 1, wherein: The input shaft is rotatably supported within the housing by one or more bearings coaxially aligned with the rotor.

7. The steer-by-wire device of claim 1, comprising at least one magnet rigidly attached to or integrally formed with the input shaft, the magnet being adjacent to the sensor.

8. The steer-by-wire device according to claim 7, wherein: The sensor comprises a Hall Effect sensor for detecting the rotation of the magnet.

9. The steer-by-wire device according to claim 1, wherein: The input shaft and the recessed portion of the rotor comprise a triple drive arrangement, thereby having three first contact points and three second contact points.

10. The steer-by-wire device according to claim 9, wherein: The first contact point and the second contact point are a first contact plane and a second contact plane, respectively.

11. The steer-by-wire device according to claim 1, wherein: The input shaft and the recessed portion of the rotor comprise a square drive arrangement, thereby having four first contact points and four second contact points.

12. The steer-by-wire device according to claim 1, wherein: The rotor includes an inner portion and an outer portion, wherein the inner portion is rotatable relative to the outer portion.

13. The steer-by-wire device according to claim 12, wherein: The inner portion is connected to the outer portion by a plurality of radially oriented ribs extending between the inner portion and the outer portion, each of the ribs being disposed within a respective channel radially formed in the outer portion such that each rib has a first end connected to the inner portion and a second end opposite the first end connected to the outer portion, each rib being spaced apart from the outer portion along the length of each respective channel.

14. The steer-by-wire device according to claim 13, wherein: The rib is flexible in the direction of rotation of the input shaft to allow relative rotational movement of the inner portion with respect to the outer portion.

15. The steer-by-wire device according to claim 14, wherein: the outer portion including a plurality of grooves formed in and circumferentially spaced about an inner radial surface of the outer portion; The inner portion includes a plurality of radially projecting stops, each of the stops being located within a respective one of a plurality of grooves formed in the outer portion; and A gap between the stopper and the groove in a rotational direction of the input shaft is smaller than a gap defined between the rib and the outer portion, so that the rib does not contact the outer portion except at the second end during operation of the steer-by-wire device.

16. The steer-by-wire device according to claim 1, wherein: The at least two pole sets include metal such that magnetic flux can flow from the coil through the at least two pole sets.

17. The steer-by-wire device according to claim 1, wherein: The rotor includes an inner portion and an outer portion; The outer portion includes a cavity defining an inner perimeter of the outer portion; The inner portion is disposed within a cavity of the outer portion; and The inner portion is flexibly coupled to the outer portion such that the inner portion can rotate within a first angular range of motion of the rotor without causing corresponding rotational motion of the outer portion within the first angular range, the first angular range being less than a total angular range of motion of the rotor between specified end stops, each of the end stops corresponding to a limit of a steering angle of the vehicle.

18. The steer-by-wire device according to claim 17, wherein: The inner part has an oval or elliptical outer periphery, and the outer part has an oval or elliptical inner periphery, and the oval or elliptical shape of the outer periphery of the inner part is smaller than the oval or elliptical shape of the inner periphery of the outer part to define a circumferential gap between the inner part and the outer part, and the circumferential gap defines the first angular range of movement.

19. The steer-by-wire device of claim 18, comprising a gasket disposed continuously around and within the gap between the inner portion and the outer portion, the gasket comprising a compliant material.

20. The steer-by-wire device according to claim 19, wherein: The compliant material includes a compressible viscoelastic material.

21. The steer-by-wire device according to claim 17, wherein: The outer portion includes a ring extending radially inwardly from an inner periphery of the outer portion; and The interior includes a first interior and a second interior having a circumferential recess formed therein, the ring of the outer portion being disposed in the recess when the first interior and the second interior are assembled together within the cavity of the outer portion.

22. The steer-by-wire device of claim 21 , comprising a washer disposed within a circumferential recess defined by the inner portion so that the inner portion does not contact the outer portion when the rotor rotates within an angular range between specified end stops, each of the end stops corresponding to a limit of the steering angle of the vehicle.

23. The steer-by-wire device according to claim 22, wherein: The gasket comprises a compliant material.

24. The steer-by-wire device according to claim 23, wherein: The compliant material includes a compressible viscoelastic material.

25. The steer-by-wire device according to claim 21, wherein: The first inner portion and the second inner portion are fixed together to rotate in unison within the cavity of the outer portion.

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