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CN-121990035-A - Torque feedback unit, steer-by-wire system and vehicle

CN121990035ACN 121990035 ACN121990035 ACN 121990035ACN-121990035-A

Abstract

The invention relates to a torque feedback unit for a steer-by-wire system of a vehicle, comprising a rotary damper (21), a feedback motor (22) and a torque converter (23), wherein the rotary damper (21) has a first input (211) and a first output (216), the first input (211) is used for being in torsion connection with a steering wheel of the steer-by-wire system, the first output (216) is in torsion connection with a second input (231) of the torque converter (23), a second output (232) of the torque converter (23) is in torsion connection with a motor rotor (221) of the feedback motor (22), wherein the feedback motor (22) is an external rotor motor, the torque converter (23) is coaxially arranged with the motor (22), and the torque converter (23) is arranged radially inwards of a motor stator (222) of the motor (22). The invention further relates to a steer-by-wire system with such a torque feedback unit and to a corresponding vehicle.

Inventors

  • YANG RONG

Assignees

  • 舍弗勒技术股份两合公司

Dates

Publication Date
20260508
Application Date
20241106

Claims (10)

  1. 1. Torque feedback unit (2) for a steer-by-wire system of a vehicle, comprising a rotary damper (21), a feedback motor (22) and a torque converter (23), wherein the rotary damper (21) has a first input (211) and a first output (216), the torque converter (23) has a second input (231) and a second output (232), the first input (211) is in torsion connection with a steering wheel (1) of the steer-by-wire system, the first output (216) is in torsion connection with the second input (231), the second output (232) is in torsion connection with a motor rotor (221) of the feedback motor (22), wherein the feedback motor (22) is an outer rotor motor, the torque converter (23) is arranged coaxially with the feedback motor (22), and the torque converter (23) is arranged radially inside a motor stator (222) of the feedback motor (22).
  2. 2. Torque feedback unit (2) according to claim 1, characterized in that the rotary damper (21) is a magneto-rheological damper.
  3. 3. The torque feedback unit (2) according to claim 2, characterized in that the magnetorheological damper has a damper stator (212), a damper coil (213) and a damper rotor (215), wherein a magnetorheological fluid (214) is filled between the damper rotor (215) and the damper coil (213).
  4. 4. A torque feedback unit (2) according to claim 3, characterized in that the magnetorheological fluid (214) is a ferrofluid.
  5. 5. A torque feedback unit (2) according to claim 3, characterized in that a double row rolling bearing (217) is arranged between the first input (211) and the damper stator (212).
  6. 6. Torque feedback unit (2) according to any of claims 1 to 5, characterized in that the torque increasing device (23) is a planetary gear mechanism.
  7. 7. The torque feedback unit (2) according to claim 6, characterized in that the planetary gear mechanism has a sun gear and a planet carrier, wherein the sun gear is connected as the second input (231) to the first output (216) in a rotationally fixed manner, and the planet carrier is connected as the second output (232) to the motor rotor (221) in a rotationally fixed manner.
  8. 8. Torque feedback unit (2) according to claim 1, characterized in that the torque feedback unit (2) has a control device which is in signal connection with the rotary damper (21) and the feedback motor (22), the control device being able to adjust the torque output of the rotary damper (21) and the feedback motor (22) according to different operating conditions.
  9. 9. Steer-by-wire system, characterized in that it has a torque feedback unit (2) according to any one of claims 1 to 8.
  10. 10. A vehicle characterized in that it has a steer-by-wire system according to claim 9.

Description

Torque feedback unit, steer-by-wire system and vehicle Technical Field The present invention relates to the field of steer-by-wire of vehicles, and more particularly to a torque feedback unit for a vehicle and a steer-by-wire system having such a torque feedback unit. Background Conventional vehicle steering systems require a mechanical connection between the steering wheel and the steered wheels. In a steer-by-wire system, the mechanical connection is eliminated. In order to simulate the driving experience of a typical driver, i.e. simulate road feel, a torque feedback unit is required, providing a true steering feedback by simulating the steering resistance of the driving mechanical connection. DE 1020118101528 B4 discloses a torque feedback unit having a worm-driven motor which is arranged at the end of the steering column remote from the steering wheel. The worm drive achieves a high gear ratio and thus a high torque, but the gear arrangement requires a lot of space. A steer-by-wire system is known from CN 111741886B with a feedback actuator. Such a feedback actuator has an electric motor that drives a steering shaft via a drive member that is connected to the steering shaft for transmitting torque. A resistance feedback steering actuator is known from CN 116902066A, which has an electric motor module for simulating road feel, comprising a motor power assembly, a reduction gear and a torque angle sensor, wherein the reduction gear is a worm drive, and the overall structure occupies a large system space. It follows that in the torque feedback units known from the prior art more space needs to be taken up in the axial or radial direction, which obviously is disadvantageous for the arrangement of the steer-by-wire system. Or the steer-by-wire system provides feedback torque through only one high power motor, which makes the system package large and disadvantageous for flexible layout of the steering wheel. Disclosure of Invention The technical problem to be solved by the invention is to provide an improved torque feedback unit which is compact in structure, especially saves axial space, and thus enables a more flexible arrangement of the steering wheel. The above technical problem is solved by a torque feedback unit for a steer-by-wire system of a vehicle according to the present invention. The torque feedback unit comprises a rotary damper, a feedback motor and a torque increasing device. The rotary damper has a first input end and a first output end, the first input end is in torsion-resistant connection with a steering wheel of the steer-by-wire system, and the first output end is in torsion-resistant connection with a second input end of the torque increasing device. The second output end of the torque increasing device is connected with a motor rotor of the feedback motor in a torsion-resistant mode. The feedback motor is an outer rotor motor, the torque increasing device is arranged coaxially with the feedback motor, and the torque increasing device is arranged radially inside a motor stator of the feedback motor. According to the design scheme of the invention, the road torque of the torque feedback unit is mainly provided by the rotary damper, and the feedback motor is required to provide supplementary resistance torque only under some special working conditions, such as the process of getting on or off a hand steering wheel, so that the use of a high-power motor is avoided. The feedback motor is arranged as an outer rotor motor, and the torque increasing device is arranged in the radial direction of the motor stator, so that the axial space is shortened, the occupation of the whole space of the system is reduced, and the arrangement mode and the position of the steering wheel are more flexible. In a preferred embodiment of the invention, the rotary damper is a magnetorheological damper. The rotary damper may be a hydraulic rotary damper, a pneumatic rotary damper, a magnetorheological rotary damper, an electromagnetic rotary damper, a friction rotary damper, or the like. According to a further embodiment of the invention, a magnetorheological damper is particularly preferred, which uses a magnetorheological fluid, the viscosity of which can be changed under the influence of a magnetic field, in order to provide an adjustable damping force. The magnetorheological damper has the main characteristics of high response speed, controllable damping force and compact structure, is suitable for application occasions of accurate control and quick response, and is particularly suitable for road feel simulation in a steer-by-wire system. It is further preferred that the magnetorheological damper has a damper stator, a damper coil and a damper rotor, with a magnetorheological fluid filled between the damper rotor and the damper coil. By filling the magnetorheological fluid between the rotor and the coil according to the characteristics of the magnetorheological fluid, accurate damping adjustment can be realize