Steer-by-wire system with one common shaft for multi-motor assembly

Abstract

A steer-by-wire system may include: a first motor assembly and a second motor assembly having a common shaft; a single package having an internal space accommodating the first motor assembly and the second motor assembly; a steering rack configured to be linearly movable in response to rotation of a common axis of the first motor assembly and the second motor assembly; and a rotational-linear conversion mechanism operably connected between a common shaft of the first motor assembly and the second motor assembly and the steering rack, and a rotational-linear conversion mechanism configured to convert rotational motion of one common axis of the first motor assembly and the second motor assembly into linear motion for linearly moving the steering rack. A seal may be positioned between the first motor assembly and the second motor assembly in the interior space of the single package.

Description

[0001] Cross-referencing of related patent applications

[0002] This application claims the benefit of U.S. Patent Application No. 63 / 692,007, filed September 6, 2024, entitled “STEER-BY-WIRESYSTEM”, the entire contents of which are incorporated herein by reference. Technical Field

[0003] Various embodiments of this disclosure generally relate to steering systems for vehicles, and more specifically to apparatus and methods for controlling steer-by-wire systems. Background Technology

[0004] Vehicles require a steering system to control their direction of travel. Previously, mechanical steering systems were used. Mechanical steering systems typically include mechanical links or connections between the steering wheel and the vehicle's wheels. For example, in a conventional steering system, the components include a steering wheel, steering column, power-assisted rack and pinion system, and linkage. The driver turns the steering wheel, which, through various mechanical components, causes the vehicle's wheels to rotate. Thus, the movement of the steering wheel causes a corresponding movement of the wheels. This mechanical system is typically assisted by hydraulic power or an electric motor.

[0005] Mechanical steering systems are expected to be replaced or supplemented by electrically driven steering systems, often referred to as "steer-by-wire" systems. These systems utilize one or more sensors, actuators, or electronic devices to varying degrees to replace, for example, the mechanical linkage between the steering wheel and the road wheels. Steer-by-wire systems aim to eliminate the physical or mechanical connection between the steering wheel and the vehicle wheels and to change the direction of the vehicle wheels and provide feedback to the driver using an electric motor. Although the mechanical linkage between the steering wheel and the road wheels is eliminated, steer-by-wire systems are expected to not only produce the same functionality and steering feel as traditional mechanically linked steering systems but also to achieve advanced steering system functions. The requirements for both traditional and advanced steering functions, such as adjustable steering feel, can be achieved through advanced control system design.

[0006] The following implementation is described in consideration of these and other general considerations. Furthermore, although relatively specific problems have been discussed, it should be understood that the implementation should not be limited to solving the specific problems identified in the background art. Summary of the Invention

[0007] According to the attached Figure 1The features and advantages of this disclosure will become more readily understood and apparent from the following detailed description and from the claims that accompany the detailed specification.

[0008] According to various embodiments of the present disclosure, a steer-by-wire system may include: a first motor assembly and a second motor assembly having a common shaft operably coupled to a steering rack; and a steering rack configured to move linearly in response to rotation of the common shaft of the first motor assembly and the second motor assembly.

[0009] The first motor assembly may include a first rotor, a first stator, and a first circuit, and the second motor assembly includes a second rotor, a second stator, and a second circuit, wherein the first rotor of the first motor assembly and the second rotor of the second motor assembly are fixedly connected to a common shaft that is operably connected to a steering rack.

[0010] The steer-by-wire system may also include a single package having an internal space for accommodating a first motor assembly and a second motor assembly, wherein a seal is positioned between the first motor assembly and the second motor assembly within the internal space of the single package.

[0011] The steer-by-wire system may also include a rotation-to-linear conversion mechanism operably connected between a common axis of the first motor assembly and the second motor assembly and a steering rack, and the rotation-to-linear conversion mechanism is configured to convert rotational motion of the first motor assembly and the second motor assembly onto a common axis into linear motion for linearly moving the steering rack.

[0012] The steer-by-wire system may also include a belt rotatably connected to a common shaft of the first motor assembly and the second motor assembly, and a rotation-linear conversion mechanism.

[0013] The steer-by-wire system may also include at least two belts, which are arranged parallel to each other and connected to a common axis of the first motor assembly and the second motor assembly, as well as a rotation-linear conversion mechanism.

[0014] The steer-by-wire system may also include a flange located between at least two belts, the flange being coupled to a common shaft of a first motor assembly and a second motor assembly, such that the at least two belts are positioned spaced apart from each other.

[0015] The steer-by-wire system may also include a belt and a first gear, which are connected to a common shaft of a first motor assembly and a second motor assembly.

[0016] The steer-by-wire system also includes a second gear configured to: maintain a gap between the teeth of the first gear and the teeth of the second gear when the belt is in good condition; and engage the second gear with the first gear when the belt is in poor condition, thereby causing the second gear to rotate via the first gear connected to a common shaft of the first motor assembly and the second motor assembly.

[0017] The first motor assembly may include an inductive first motor position sensor configured to sense the angular position of the first motor of the first motor assembly; and the second motor assembly may include an inductive second motor position sensor configured to sense the position of the second motor of the second motor assembly.

[0018] The first motor assembly may include an inductive first motor position sensor configured to sense the angular position of the first motor of the first motor assembly; and the second motor assembly may include a magnetic second motor position sensor configured to sense the position of the second motor of the second motor assembly.

[0019] The steer-by-wire system may also include a linear position sensor configured to sense the linear position of the steering rack, and the linear position sensor being connected to one or both of a first circuit of a first motor assembly and a second circuit of a second motor assembly.

[0020] The first rotor and first stator of the first motor assembly, and the second rotor and second stator of the second motor assembly, can be disposed between the first circuit of the first motor assembly and the second circuit of the second motor assembly.

[0021] The first rotor and the first stator of the first motor assembly may be disposed between the seal and the first circuit of the first motor assembly, and the second rotor and the second stator of the second motor assembly may be disposed between the seal and the second circuit of the second motor assembly.

[0022] This invention is provided to introduce a series of concepts in a simplified form, which will be further described in the detailed description below. This invention is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter. Attached Figure Description

[0023] Various embodiments according to this disclosure will be described with reference to the accompanying drawings, in which:

[0024] Figure 1 This is a schematic diagram of a vehicle including a steer-by-wire system according to an exemplary embodiment of the present disclosure;

[0025] Figures 2 to 4 This is a schematic diagram illustrating a steer-by-wire system according to an exemplary embodiment of the present disclosure.

[0026] Figure 5 This is a partial cross-sectional view of a steer-by-wire system according to an exemplary embodiment of the present disclosure.

[0027] Unless otherwise stated, corresponding numbers and symbols in the various figures generally refer to corresponding parts. The figures are drawn to clearly illustrate relevant aspects of the embodiments and are not necessarily drawn to scale. Detailed Implementation

[0028] In the following detailed description, reference is made to the accompanying drawings, which form a part of this disclosure, in which specific embodiments in which the invention may be practiced are illustrated by way of example. These embodiments are described in sufficient detail to enable those skilled in the art to practice the invention, and it will be understood that other embodiments may be utilized and structural, logical, and electrical changes may be made without departing from the spirit and scope of the invention. Therefore, the following detailed description should not be regarded as a limiting description, and the scope of the invention is defined only by the appended claims and their equivalents. Similar reference numerals in the drawings indicate similar parts, which should be obvious in use.

[0029] Now for reference Figure 1 The diagram illustrates a steer-by-wire system 10 for use in a vehicle 1. In conventional automotive steering systems, such as electric power steering (EPS) systems, the steering wheel is mechanically linked to one or more road wheels (e.g., the front road wheels). However, the steer-by-wire system 10 according to embodiments of this disclosure eliminates this mechanical connection, and instead, the steering angle of the road wheels 30 is electronically controlled based on measurements from the steering wheel or manual wheel 20 and / or one or more control signals from the controller 50, and feedback is provided to the driver or operator of the vehicle 1 using multiple actuators such as electric motors. Furthermore, in the steer-by-wire system 10, the steering angle of the road wheels 30 can be controlled by one or more control signals generated by the vehicle driving system or advanced driver assistance system (ADAS) and / or by the controller 50 based on data from one or more sensors.

[0030] The steer-by-wire system 10 allows the driver or operator of vehicle 1 to control the direction of vehicle 1 or the road wheels 30 of vehicle 1 by manipulating the steering wheel 20. The steering wheel 20 is operatively or mechanically coupled or fixed to the steering axle (or steering column) 22. The steering wheel 20 may be directly or indirectly connected to the steering axle 22. For example, the steering wheel 20 may be connected to the steering axle 22 via gears, shafts, belts, and / or any connecting device. Alternatively, the steering wheel 20 may be fixed to the steering axle 22. The steering axle 22 may rotate together with the steering wheel 20.

[0031] One or more steering wheel sensors 40 may be configured to detect the position, angular displacement, or travel 25 of the steering shaft 22 or steering wheel 20, and to detect the torque of the angular displacement or travel 25 of the steering shaft 22 or steering wheel 20. The steering wheel sensors 40 provide electrical signals to the controller 50 indicating the angular displacement and / or torque 25. The controller 50 sends signals to and / or receives signals from the upper actuator 27 (e.g., a steering feedback actuator with an electric motor) to actuate the upper actuator 27 in response to the angular displacement and / or torque 25 of the steering wheel 20. The upper actuator 27 rotates or moves the steering wheel 20 in response to a control signal received from the controller 50 to provide feedback to the driver or operator (similar to the feedback provided by the wheels in a manually steering vehicle).

[0032] In the steer-by-wire system 10, the steering wheel 20 can be mechanically separated from the road wheels 30. Therefore, the steer-by-wire system 10 needs to provide the driver or operator with the same "road feel" as the driver receives through a direct mechanical connection. Furthermore, it is desirable to have a device that provides a backup mechanical "road feel" in the event of multiple electronic failures in the steer-by-wire system. Additionally, it is desirable for the device to provide a clear on-center feel and accurate torque changes when the steering wheel is rotated. Therefore, the vehicle 1 may include an upper actuator 27 (e.g., a steering feedback actuator).

[0033] The upper actuator 27 may include, for example, but not limited to, an electric motor connected to the steering shaft or steering column 22. For example, a gear or belt assembly may connect the output of the steering feedback actuator 27 to the steering shaft 22. Alternatively, the steering feedback actuator 27 may be directly coupled to the steering shaft 22 or the steering wheel 20. The steering feedback actuator 27 can be actuated to provide resistance to the rotation of the steering wheel 20. The controller 50 is electrically coupled to the sensor 40 and the steering feedback actuator 27. The controller 50 receives signals from the sensor 40 indicating the torque and angular rotation 25 applied to the steering wheel 20. In response to the signals from the sensor 40, the controller 50 generates and transmits signals corresponding to the sensed torque and angular rotation of the steering wheel 20 sensed by the sensor 40, and the steering feedback actuator 27 generates a resistance torque to the rotation of the steering wheel 20 in response to the signals from the controller 50 to provide steering feel to the driver.

[0034] The controller 50 also transmits signals or commands to the lower actuator 32 (e.g., a road wheel actuator). The lower actuator 32 controls the linear movement of the steering rack 36 in response to the control signal received from the controller 50. For example, the lower actuator 32 generates rotational movement in response to the control signal from the controller 50, and this rotational movement of the lower actuator 32 is converted into linear movement of the steering rack 36. The tie rod and joint 37 connect the steering rack 36 to the road or vehicle wheel 30 and convert the linear movement of the steering rack 36 into rotation of the road wheel 30.

[0035] In use, the steering wheel 20 is displaced at an angle 25, causing the steering shaft 22 to also be displaced at an angle. The sensor 40 detects the angular displacement and torque 25 of the steering shaft 22 connected to the steering wheel 20, and sends a signal to the controller 50 indicating the relative amounts of the angular displacement and torque 25 of the steering shaft 22. The controller 50 sends a control signal to the lower actuator 32 indicating the relative amounts of the angular displacement and / or torque of the steering shaft 22. In response, the lower actuator 32 moves the steering rack 36, causing the road wheels 30 to rotate. Therefore, the controller 50 controls the distance the steering rack 36 moves based on the amount of the angular displacement 25 of the steering wheel 20. The movement of the steering rack 36 manipulates the linkage and joint 37 to reposition the road wheels 30 of the vehicle 1. Accordingly, when the steering wheel 20 rotates, the road wheels 30 are controlled to rotate.

[0036] To perform the prescribed functions and required processing, and thus perform calculations (e.g., motor parameter identification, one or more control algorithms, etc.), controller 50 may include, but is not limited to: one or more processors, one or more computers, one or more digital signal processors (DSPs), memory, registers, one or more registers, timers, one or more interrupts, one or more communication interfaces, and input / output signal interfaces, as well as combinations including at least one of the foregoing. For example, controller 50 may include input signal processing and filtering to enable accurate sampling, conversion, or acquisition of these signals from the communication interface. Although Figure 1 The controller 50 is shown as a single controller, but those skilled in the art will understand that the controller 50 may be distributed among multiple vehicle controllers.

[0037] Figures 2 to 4 This is a schematic diagram illustrating a steer-by-wire system according to an exemplary embodiment of the present disclosure.

[0038] The lower actuator 32 (e.g., a road wheel actuator) may include a first motor assembly 100 and a second motor assembly 200, the first motor assembly 100 and the second motor assembly 200 having a single common shaft 300.

[0039] Each package 400 has an internal space that houses the first motor assembly 100 and the second motor assembly 200. A seal 410 is positioned between the first motor assembly 100 and the second motor assembly 200 such that each of the first motor assembly 100 and the second motor assembly 200 can be sealed independently.

[0040] The first motor assembly 100 may include a first rotor 110, a first stator 120, and a first circuit 130. The first rotor 110 is configured to rotate relative to the first stator 120. The first circuit 130 and the first stator 120 are directly or indirectly connected to a non-rotatable portion of a single package 400. The first rotor 110 and the first stator 120 are positioned between a seal 410 and the first circuit 130.

[0041] The second motor assembly 200 may include a second rotor 210, a second stator 220, and a second circuit 230. The second rotor 210 is configured to rotate relative to the second stator 220. The second stator 220 is directly or indirectly coupled to a non-rotatable portion of a single package 400. The second rotor 210 and the second stator 220 are positioned between a seal 410 and the second circuit 230.

[0042] The first rotor 110 and the first stator 120, as well as the second rotor 210 and the second stator 220, are arranged to face each other, such that the first rotor 110 and the first stator 120, as well as the second rotor 210 and the second stator 220 are disposed between the first circuit 130 and the second circuit 230.

[0043] The first circuit 130 and the second circuit 230 may include any suitable circuitry and electronic components, such as a microprocessor mounted thereon. The first circuit 130 and the second circuit 230 may be configured to control the first motor assembly 100 and the second motor assembly 200, for example, but not limited to: supplying power to the first motor assembly 100 and the second motor assembly 200, enabling or disabling the operation of the first motor assembly 100 and the second motor assembly 200, and changing the speed of the first rotor 110 and the second rotor 210 and / or the rotational direction of the first rotor 110 and the second rotor 210.

[0044] The first motor assembly 100 and the second motor assembly 200 have a single common shaft 300. For example, the first rotor 110 of the first motor assembly 100 and the second rotor 210 of the second motor assembly 200 are both fixedly connected to the single common shaft 300. Therefore, the single common shaft 300, the first rotor 110 of the first motor assembly 100 and the second rotor 210 of the second motor assembly 200 rotate together, and the single common shaft 300 passes through the first rotor 110 of the first motor assembly 100, the second rotor 210 of the second motor assembly 200 and the seal 410.

[0045] A single common axis 300 is operably connected to a rotary-linear conversion mechanism 500.

[0046] refer to Figure 5 The pulley 310 can be directly formed on or attached to a single common shaft 300. The pulley 310 may have an outer surface that engages with the inner surface of the belt 350. The pulley 310 of the single common shaft 300 is rotatably connected to the rotary-linear conversion mechanism 500. A first motor assembly 100 and / or a second motor assembly 200 provide rotational torque to the pulley 310 via the single common shaft 300. The rotational force of the pulley 310 is transmitted to the belt 350. When the torque is applied to the belt 350, the rotational force of the single common shaft 300 is transmitted to the rotary-linear conversion mechanism 350.

[0047] A rotary-linear conversion mechanism 500 (e.g., a nut-screw mechanism and a ball nut-screw mechanism) can be configured to convert rotational motion transmitted from a single common shaft 300 of the first motor assembly 100 and the second motor assembly 200 via a belt 350 into linear motion for linearly moving the steering rack 36. The rotary-linear conversion mechanism 500 may include a rotatable portion 510. For example, the rotatable portion 510 may include a nut or a ball nut, but is not required. At least a portion of the steering rack 32 is retained within the rotatable portion 510. The rotatable portion 510 has an internal threaded track groove 521, and at least a portion of the steering rack 32 has an external threaded track groove 615 for rotatable arrangement of the rotatable body 520 (e.g., a ball). The rotatable body 520 is disposed between the internal threaded track groove 521 of the rotatable portion 510 and the external threaded track groove 615 of the steering rack 32. The rotatable body 520 may be a metal sphere, which reduces friction and load transfer between adjacent components. The rotatable portion 510 is rotatably supported by the steering rack 32 via the rotatable body 520 and the support assembly 540. However, in an alternative embodiment of this disclosure, the internal threaded groove 521 of the rotatable portion 510 and the external threaded groove 615 of the steering rack 32 may engage directly with each other without the rotatable body 220.

[0048] The support assembly 540 is configured to rotatably support the rotary-linear conversion mechanism 500. The support assembly 540 may be positioned between the rotatable portion 510 and a non-rotating structure, such as, but not limited to, the housing 700. The support assembly 540 is used to rotatably support the rotatable portion 510 for rotation relative to the non-rotating structure.

[0049] The pulley 310 of the single common shaft 300 and the rotatable portion 510 of the rotary-linear conversion mechanism 500 are rotatably connected to each other via a belt 350. The configuration of the belt 350 allows the inner engagement surface of the belt 350 to wrap around and engage the pulley 310 of the single common shaft 300 and the ball screw pulley 515 fixed to the rotatable portion 510. The rotational motion of the pulley 310 of the single common shaft 300 causes the rotation of the rotatable portion 510 of the rotary-linear conversion mechanism 500, and then the rotational motion of the rotatable portion 510 of the rotary-linear conversion mechanism 500 is converted into the linear motion of the steering rack 32 by the rotary-linear conversion mechanism 500.

[0050] The travel stop and rack support 620 is configured to limit and support the linear range of motion of the steering rack 32. The travel stop and rack support 620 provides a stop position that limits the travel of the steering rack 32 and thus limits the linear movement of the steering rack 32, thereby preventing the steering rack 32 from exceeding the linear movement limit.

[0051] The anti-rotation support 630 is configured to restrict rotation of the steering rack 32 to prevent rotation of the steering rack 32 relative to a non-rotating structure, such as, but not limited to, the housing 700. For example, the anti-rotation support 630 includes a preloaded roller or a rotatable rack shoe, and the steering rack 32 has a flat surface or shape corresponding to the shape of the anti-rotation support 630, such that the steering rack 32 is slidable but not rotatable. A portion of the steering rack 32 has a generally D-shape and a flat surface operably associated with the anti-rotation support 630. Alternatively, the steering rack 32 has a groove (or protrusion) that keyes to a protrusion (or groove) of the anti-rotation support 630 to restrict rotational movement of the steering rack 32.

[0052] The first motor position sensor 140 and the second motor position sensor 240 are capable of responding to rotation of a single common axis 300. The first motor position sensor 140 and the second motor position sensor 240 can be configured to sense their relationship to the single common axis 300. For example, the first motor position sensor 140 and the second motor position sensor 240 can be positioned adjacent to or around the single common axis 300. The first motor position sensor 140 and the second motor position sensor 240 can respectively detect or sense the angular position of the first motor assembly 100 and the second motor assembly 200 (e.g., pulley 310 or the single common axis 300) within a single turn range, which is from zero degrees to 360 degrees (0°-360°). The first motor position sensor 140 and the second motor position sensor 240 can generate an output signal indicating the sensed angular position of the single common axis 300.

[0053] The first motor position sensor 140 and the second motor position sensor 240 can be one or more suitable devices for generating a signal in response to rotation of a single common axis 300. For example, the first motor position sensor 140 and the second motor position sensor 240 can be inductive sensors, magnetic sensors (e.g., Hall effect sensors), magnetoresistive (MR) sensors, or any other sensors known in the art with similar functionality.

[0054] An inductive sensor can be a sensor configured to operate based on the principle of electromagnetic induction to detect or measure nearby metallic objects. When current flows through an inductor, the inductor generates a magnetic field. Alternatively, when the magnetic field through the inductor changes, current flows through a circuit including the inductor. This effect can be used to detect metallic objects that interact with a magnetic field. For example, an inductive sensor according to an embodiment of this disclosure can utilize aspects described in U.S. Patent Application Serial No. 18 / 930,897 entitled “INDUCTIVE SENSOR SYSTEM COMPRISING INDUCTIVE TORQUE AND POSITION SENSORASSEMBLIES,” the entire contents of which are incorporated herein by reference. In an embodiment of the inductive sensor, an excitation or transmitter coil assembly configured to generate a magnetic field on a single common axis 300 and a receiver coil assembly configured to detect the magnetic field around the single common axis 300 may be included in or mounted to a first circuit board 130 or a second circuit board 230. A target with a metallic pattern or one or more conductive loops configured to influence the magnetic field generated by the excitation or transmitter coil assembly may be included in or attached to the single common axis 300.

[0055] In embodiments of a magnetic sensor (e.g., a Hall effect sensor), a single common axis 300 may include a magnetic gradient formed on the surface of the single common axis 300, defined by a plurality of alternating north-south magnetically charged elements spaced circumferentially around the outer periphery of the single common axis 300. A magnetic sensor configured to sense or detect a magnetic field around the single common axis 300 may be included in or mounted to a first circuit board 130 or a second circuit board 230.

[0056] The first motor position sensor 140 and the second motor position sensor 240 are electrically connected to the first circuit board 130 and the second circuit board 230, respectively.

[0057] In a first embodiment, both the first motor position sensor 140 and the second motor position sensor 240 can be inductive sensors to reduce the size of the individual package 400 and lower manufacturing costs. In a second embodiment, one of the first motor position sensor 140 and the second motor position sensor 240 can be an inductive sensor, and the other can be a magnetic sensor. In a third embodiment, both the first motor position sensor 140 and the second motor position sensor 240 can be magnetic sensors.

[0058] The linear position sensor 640 is configured to sense the linear position of the steering rack 32. The linear position sensor 640 may be electrically connected to a first circuit of the first motor assembly 100 and / or a second circuit of the second motor assembly 200, and output an electrical signal indicating the linear position of the steering rack 32.

[0059] exist Figure 2 In one implementation, a single strip 350 is connected to a single common shaft 300 and a rotary-linear conversion mechanism 500.

[0060] Alternatively, such as Figure 3 As shown in the embodiment, a double-strip structure including a first strip 350 and a second strip 351 can connect a single common shaft 300 and a rotation-linear conversion mechanism 500. Even if one of the first strip 350 and the second strip fails, the other strip, which is functioning normally, can transmit the rotational force of the single common shaft 300 to the rotation-linear conversion mechanism 500. The first strip 350 and the second strip 351 are arranged parallel to each other. A flange 352 can be positioned between the first strip 350 and the second strip 351, such that the first strip 350 and the second strip 351 are positioned spaced apart from each other to hold the first strip 350 and the second strip 351 in place and prevent mutual interference.

[0061] exist Figure 4 In another embodiment, in addition to the belt 350, a spare gear assembly 360 may be included. The spare gear assembly 360 may include a first gear 361 coupled to a single common shaft 300 and a second gear 362 coupled to a rotary-linear conversion mechanism 500. When the belt 350 is functioning properly (e.g., when the belt 350 properly connects the single common shaft 300 and the rotary-linear conversion mechanism 500 and is able to transmit rotational torque to the rotary-linear conversion mechanism 500), a clearance may be maintained between the teeth of the first gear 361 and the teeth of the second gear 362. For example, one of the teeth of the first gear 361 and the teeth of the second gear 362 may be smaller or narrower than the other to provide clearance between the teeth of the first gear 361 and the teeth of the second gear 362. However, when the belt 350 fails (e.g., the belt 350 becomes loose or breaks), the teeth of the second gear 362 contact or engage with the teeth of the first gear 361, so that the rotation of the first gear 361 can cause the second gear 362 to rotate. Therefore, even when the belt 350 fails, the rotational torque of the single common shaft 300 can be transmitted to the rotation-linear conversion mechanism 500.

[0062] While exemplary embodiments have been described in detail, it should be understood that various changes, substitutions and alterations may be made herein without departing from the spirit and scope of this application as defined by the appended claims.

[0063] Furthermore, the scope of this application is not intended to be limited to the specific embodiments of the processes, machines, manufactures, compositions of substances, apparatuses, methods, and steps described in the specification. As will be readily understood by those skilled in the art from this disclosure, processes, machines, manufactures, compositions of substances, apparatuses, methods, or steps that exist now or will be developed thereafter and perform substantially the same function or achieve substantially the same result as the corresponding embodiments described herein can be utilized according to embodiments and alternative embodiments. Therefore, the appended claims are intended to include such processes, machines, manufactures, compositions of substances, apparatuses, methods, or steps within their scope.

Claims

1. A steer-by-wire system, comprising: a first motor assembly and a second motor assembly having a common shaft operatively coupled to a steering rack; and the steering rack configured to move linearly in response to rotation of the common shaft of the first and second motor assemblies.

2. The steer-by-wire system of claim 1, wherein: the first motor assembly includes a first rotor, a first stator, and a first circuit, the second motor assembly includes a second rotor, a second stator, and a second circuit, and the first rotor of the first motor assembly and the second rotor of the second motor assembly are fixedly coupled to the common shaft operatively coupled to the steering rack.

3. The steer-by-wire system of claim 1, further comprising a single package having an interior space containing the first and second motor assemblies, wherein a seal positioned between the first and second motor assemblies in the interior space of the single package.

4. The steer-by-wire system of claim 1, further comprising a rotary-linear conversion mechanism operatively connected between the common shaft of the first and second motor assemblies and the steering rack, and configured to convert rotational motion of the common shaft of the first and second motor assemblies to linear motion for linearly moving the steering rack.

5. The steer-by-wire system of claim 4, further comprising a belt rotatably coupled to the rotary-linear conversion mechanism and the common shaft of the first and second motor assemblies.

6. The steer-by-wire system of claim 4, further comprising at least two belts disposed parallel to each other and coupled to the rotary-linear conversion mechanism and the common shaft of the first and second motor assemblies.

7. The steer-by-wire system of claim 6, further comprising a flange portion positioned between the at least two belts and coupled to the common shaft of the first and second motor assemblies such that the at least two belts are positioned spaced apart from each other.

8. The steer-by-wire system of claim 4, further comprising a belt and a first gear coupled to the common shaft of the first and second motor assemblies.

9. The steer-by-wire system of claim 4, further comprising a second gear configured to maintain a gap between a toothed portion of the first gear and a toothed portion of the second gear in a condition in which the belt is not faulty, and to cause the second gear to engage with the first gear in a condition in which the belt is faulty, thereby causing the second gear to rotate via the first gear coupled with the one common shaft of the first motor assembly and the second motor assembly.

10. The steer-by-wire system of claim 1, wherein: the first motor assembly includes an inductive first motor position sensor configured to sense an angular position of a first motor of the first motor assembly; and the second motor assembly includes an inductive second motor position sensor configured to sense a position of a second motor of the second motor assembly.

11. The steer-by-wire system of claim 1, wherein: the first motor assembly includes an inductive first motor position sensor configured to sense an angular position of a first motor of the first motor assembly; and the second motor assembly includes a magnetic second motor position sensor configured to sense a position of a second motor of the second motor assembly.

12. The steer-by-wire system of claim 2, further comprising a linear position sensor configured to sense a linear position of the steering rack, and connected to one or both of the first circuit of the first motor assembly and the second circuit of the second motor assembly.

13. The steer-by-wire steering system of claim 2, wherein, the first rotor and the first stator of the first motor assembly and the second rotor and the second stator of the second motor assembly are disposed between the first circuit of the first motor assembly and the second circuit of the second motor assembly.

14. The steer-by-wire system of claim 3, wherein: the first rotor and the first stator of the first motor assembly are disposed between the seal and the first circuit of the first motor assembly, and the second rotor and the second stator of the second motor assembly are disposed between the seal and the second circuit of the second motor assembly.

15. A steer-by-wire system, comprising: a first motor assembly and a second motor assembly having one common shaft; a single package having an interior space that houses the first motor assembly and the second motor assembly; a steering rack configured to linearly move in response to rotation of the one common shaft of the first motor assembly and the second motor assembly; and a single seal disposed between the first motor assembly and the second motor assembly. a rotary-linear conversion mechanism operably connected between the one common shaft of the first motor assembly and the second motor assembly and the steering rack, and configured to convert a rotary motion of the one common shaft of the first motor assembly and the second motor assembly into a linear motion for linearly moving the steering rack.

16. The steer-by-wire system according to claim 15, wherein: the first motor assembly includes a first rotor, a first stator, and a first circuit, the second motor assembly includes a second rotor, a second stator, and a second circuit, and the first rotor of the first motor assembly and the second rotor of the second motor assembly are fixedly coupled to the one common shaft operably coupled to the steering rack.

17. The steer-by-wire system according to claim 15, wherein: a seal is positioned between the first motor assembly and the second motor assembly in an interior space of the single package.

18. The steer-by-wire system according to claim 15, further comprising a belt rotatably coupled to the rotary-linear conversion mechanism and the one common shaft of the first motor assembly and the second motor assembly.

19. The steer-by-wire system according to claim 15, further comprising at least two belts disposed parallel to each other and coupled to the rotary-linear conversion mechanism and the one common shaft of the first motor assembly and the second motor assembly.

20. The steer-by-wire system according to claim 18, further comprising: a belt and a first gear coupled to the one common shaft of the first motor assembly and the second motor assembly; and a second gear configured to maintain a gap between teeth of the first gear and teeth of the second gear in a state where the belt is not malfunctioning, and to engage the second gear with the first gear to rotate the second gear via the first gear coupled to the one common shaft of the first motor assembly and the second motor assembly in a state where the belt is malfunctioning. ​

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