A kind of steering-by-wire automobile steering wheel road feeling simulation feedback device

Abstract

The application discloses a kind of feel simulation feedback devices of steering wheel of steer-by-wire automobile, including pipe column lower shaft and worm wheel shaft assembly, wherein, one end of worm wheel shaft assembly is connected with pipe column lower shaft, the other end is connected with worm wheel;Worm wheel shaft assembly includes torsion bar and worm wheel connecting shaft, one end of torsion bar is fixedly connected with input shaft, input shaft is fixedly connected with pipe column lower shaft, torsion bar is fixedly connected with worm wheel connecting shaft, input shaft is connected with worm wheel connecting shaft, and the junction of input shaft and worm wheel connecting shaft is configured to have relative rotatable angle R°, after input shaft and worm wheel connecting shaft relative rotation exceeds R°, the limit surface of input shaft and worm wheel connecting shaft can be attached, including torque & angle sensor assembly and ECU motor assembly, the application can be applied to vehicle with steer-by-wire.For the steering wheel of steer-by-wire vehicle provides steering damping, torque change, angle & torque acquisition transmission and feedback to road surface in the process of vehicle running.

Description

Technical Field

[0001] This invention relates to the field of automotive electric power steering systems, specifically to a steer-by-wire vehicle steering wheel road feel simulation feedback device. Background Technology

[0002] The automotive steering system has evolved through stages: mechanical steering, hydraulic power steering (HPS), electro-hydraulic power steering (EHPS), and electric power steering (EPS). Currently, with the development of automotive electrification, intelligence, advanced driver assistance systems, and the application of autonomous driving, steer-by-wire (steer-by-wire) has emerged as a key component for achieving advanced autonomous driving. It's called steer-by-wire because it eliminates the intermediate shaft between the traditional steering column and steering gear, thus eliminating the mechanical connection. Instead, it uses sensors and the ECU (Electronic Control Unit) via wiring harnesses to transmit signals between the steering wheel and steering gear. (See reference...) Figure 1 As shown in the diagram, A represents the steering column, B the steering gear, and C the wiring harness. The steering gear receives angle signals from sensors under the steering wheel and the ECU, which are then processed by the ECU to achieve synchronous rotation of the vehicle's wheels. This allows the positions of the steering column and steering gear to be no longer limited by the steering hardpoint, enabling more flexible vehicle design and chassis layout; it also allows the steering ratio to be flexible and no longer a fixed value; and it isolates wheel vibration transmission and steering column collision intrusion, improving comfort and safety. Summary of the Invention Summary of the Invention

[0004] To address the technical problems existing in the prior art, the present invention provides a steer-by-wire vehicle steering wheel road feel simulation feedback device.

[0005] To solve the above-mentioned technical problems, the present invention provides the following technical solution:

[0006] This invention is a steering wheel road feel simulation feedback device for steer-by-wire automobiles, including a lower shaft of a column and a worm gear shaft assembly, wherein one end of the worm gear shaft assembly is connected to the lower shaft of the column and the other end is connected to the worm gear.

[0007] The worm gear shaft assembly includes a torsion bar and a worm gear connecting shaft. One end of the torsion bar is fixedly connected to the input shaft, the input shaft is fixedly connected to the lower shaft of the tube column, the torsion bar is fixedly connected to the worm gear connecting shaft, and the input shaft is connected to the worm gear connecting shaft. The connection between the input shaft and the worm gear connecting shaft is configured to have a relative rotation angle R°. After the relative rotation of the input shaft and the worm gear connecting shaft exceeds R°, the limiting surfaces of the input shaft and the worm gear connecting shaft can fit together.

[0008] This includes a torque and angle sensor assembly and an ECU motor assembly. The sensor assembly includes a sensor rotor and a sensor stator. The sensor rotor is fixedly mounted on the worm gear connecting shaft, and the sensor stator is fixedly mounted on the input shaft. The ECU motor assembly is connected to the torque and angle sensor assembly through a sensor wiring harness. The ECU motor assembly is connected to the steering gear and the vehicle ECU through upper and lower connecting wiring harnesses. The output end of the ECU motor assembly is connected to a worm gear. The worm gear is a single-start self-locking worm gear. The worm gear meshes with a worm wheel, and the worm wheel is fixedly connected to the worm gear connecting shaft.

[0009] Furthermore, it also includes an end cap assembly, which includes an end cap and an end cap bearing. The end cap covers the connection between the lower shaft of the tube column and the worm gear shaft assembly, and the end cap bearing is rotatably connected to the input shaft.

[0010] Furthermore, the input shaft is designed with a stepped surface, which has a 1mm gap with the end cover assembly after assembly. If the end cover bearing falls off, the stepped surface will restrict the inner ring of the end cover bearing and prevent the end cover bearing from falling off.

[0011] Furthermore, the input shaft and the worm gear connecting shaft have two stepped connection structures. In the first structure, the input shaft and the worm gear connecting shaft are provided with limiting surfaces opposite each other, and the limiting surfaces are configured to have a relative rotation angle R°. The second structure is equipped with a needle roller bearing.

[0012] Furthermore, R° is ±5.5°.

[0013] Furthermore, it also includes a reduction housing assembly, which consists of a reduction housing, a deep groove ball bearing, a four-point contact ball bearing, and an adjusting bushing. The outer rings of the deep groove ball bearing and the four-point contact ball bearing are fixed to the inner hole of the reduction housing 6a by an interference fit. The adjusting bushing is also connected to the reduction housing by an interference fit between the worm gear cavity and the reduction housing.

[0014] Furthermore, it also includes a worm gear assembly, which includes a claw coupling, a rivet ring, a self-aligning deep groove ball bearing, a worm, and a worm end bearing. The inner rings of both the self-aligning deep groove ball bearing and the worm end bearing are press-fitted into the worm with an interference fit. The worm is designed with a riveting groove. The rivet ring is deformed and pressed into the riveting groove by pressing against the inner ring of the self-aligning deep groove ball bearing and riveting, thereby locking the self-aligning deep groove bearing and the worm. The head of the worm is pressed into the claw coupling, thereby connecting to the motor.

[0015] Furthermore, the self-aligning deep groove ball bearing and the reduction housing are fitted with a clearance fit. It also includes a worm screw plug, which is screwed in by an external thread that fits with the internal thread of the reduction housing. The outer ring of the self-aligning deep groove ball bearing is locked with a locking torque, thereby locking the entire worm assembly and preventing the worm assembly from moving within the reduction housing. The worm can swing around the swing center of the self-aligning deep groove ball bearing, that is, the worm can move up and down with the worm end bearing within the elliptical hole of the adjusting bushing, so as to realize the adjustable clearance between the worm wheel and the worm.

[0016] Furthermore, it also includes a spring plunger consisting of a spring pin, a spring, and a plunger. The spring and spring pin are installed inside the plunger. The spring pin can extend and retract axially with the spring. The spring plunger can be screwed into the mating threaded hole of the reduction housing through the external thread of the plunger. The spring pin acts on the worm end bearing through the through hole of the adjusting bushing. By adjusting the tightening force of the spring plunger 7, a suitable worm wheel and worm clearance value can be achieved.

[0017] Furthermore, it also includes a limit block. The limit block is rotated to the center position of the steering wheel by using a threaded hole to engage with the worm gear shaft. Then, two guide bolts are screwed into the threaded holes of the reduction housing through the two through holes of the limit block. When the steering wheel is rotated, it drives the worm gear shaft to rotate. Through the external thread of the worm gear shaft and the rotation and fixation of the guide bolts, the limit block can only move up and down in the axial direction of the worm gear shaft. When the steering wheel rotates one revolution, the distance that the limit block moves is exactly equal to the pitch. By setting the distance between the limit block and the upper and lower limit surfaces, the number of revolutions of the steering wheel can be limited.

[0018] The beneficial effects of this invention are:

[0019] This invention can be applied to vehicles equipped with steer-by-wire. It provides steering damping, torque variation, angle and torque acquisition and transmission, and feedback on the road surface during vehicle operation for the steering wheel of steer-by-wire vehicles. This enables the control, driving feel, and signal transmission and feedback of steer-by-wire vehicles. Attached Figure Description

[0020] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0021] Figure 1 This is a schematic diagram of the overall structure of the steer-by-wire system of the present invention;

[0022] Figure 2 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 3 yes Figure 2 Sectional view along axis AA;

[0024] Figure 4This is the present invention. Figure 2 BB-direction sectional view.

[0025] In the diagram, 1. Lower shaft of the tubing column; 2. Pin; 3. Input worm gear shaft assembly; 3a. Input shaft; 3b. Cylindrical pin; 3c. O-ring; 3d. Torque bar; 3e. Torque & angle sensor stator; 3f. Torque & angle sensor rotor; 3g. Needle roller bearing; 3h. Worm gear; 3i. Worm gear shaft; 4. End cover assembly; 4a. End cover; 4b. End cover bearing; 5. Hexagonal flange bolt; 6. Reduction housing assembly; 6a. Reduction housing; 6b. Deep groove ball bearing; 6c. Four-point contact ball bearing; 6d. 7. Adjusting bushing; 7a. Spring plunger; 7b. Spring pin; 7c. Plunger; 8. Worm gear assembly; 8a. Claw coupling; 8b. Rivet ring; 8c. Self-aligning deep groove ball bearing; 8d. Worm; 8e. Worm end bearing; 9. Lock nut; 10. Limit block; 11. Guide post bolt; 12. Socket head cap screw; 13. ECU motor assembly; 14. Upper and lower connecting harness assembly; 15. Sensor harness assembly; 16. Worm screw plug; 17. Coupling buffer pad. Detailed Implementation

[0026] The preferred embodiments of the present invention will be described below with reference to the accompanying drawings. It should be understood that the preferred embodiments described herein are for illustration and explanation only and are not intended to limit the present invention.

[0027] This invention provides a steer-by-wire vehicle steering wheel road feel simulation feedback device, such as... Figure 2As shown, the steer-by-wire vehicle steering wheel road feel simulation device of the present invention mainly consists of a lower shaft 1, a pin 2, an input worm gear shaft assembly 3, an end cover assembly 4, a hexagonal flange screw 5, a reduction housing assembly 6, a spring plunger 7, a worm gear assembly 8, a lock nut 9, a limit block 10, a guide post bolt 11, an internal hexagonal flower-shaped cylindrical head screw 12, an ECU motor assembly 13, upper and lower connecting wiring harness assemblies 14, a sensor wiring harness assembly 15, a worm gear plug 16, and a coupling buffer pad 17. When we start turning the steering wheel, before it moves, the steering wheel torque is transmitted to the input shaft 3a via the upper shaft of the column and the lower shaft 1. Due to the presence of the worm gear 3h and worm 8d reduction mechanism, the input shaft 3a cannot drive the worm gear shaft 3i to rotate, causing the torsion bar 3d to deform. At this time, the sensor stator 3e on the input shaft 3a and the sensor rotor 3f on the worm gear shaft 3i detect the deformation of the torsion bar 3d, thereby obtaining a torque signal and converting it into an electrical signal. This signal is then transmitted to the ECU motor assembly 13 via the sensor wiring harness assembly 15. After calculation and analysis, the ECU motor assembly 13 begins to provide positive assist. The rotation of the motor drives the worm 8d to rotate, which in turn drives the worm gear shaft 3i and the input shaft 3a to rotate, causing the steering wheel to start turning. Simultaneously with the steering wheel rotation, the ECU motor assembly... The ECU motor assembly 13 monitors the rotation angle of the input shaft 3a in real time through the sensor stator 3e and sensor rotor 3f. Then, the ECU motor assembly 13 transmits the rotation angle signal to the steering actuator and the vehicle ECU through the upper and lower connecting wiring harness assemblies 14. The steering actuator, based on the transmission ratio and angle value set according to the current vehicle speed, can rotate the wheels by the corresponding angle to achieve vehicle direction change. At this time, when the torque increment of the input shaft 3a is zero (no active steering wheel turning), the ECU motor assembly 13 immediately provides reverse assistance and deforms the torsion bar 3d to the set torque value. If the steering wheel is kept still at this time, the hand force is equal to the set torque value and in the opposite direction, and the rotation angle between the steering wheel and the tire remains unchanged. If the steering wheel is released at this time (hand force is removed), the ECU motor assembly 13 provides reverse assistance to return the steering wheel to the origin, and the vehicle wheels return to the straight driving position. The vehicle ECU determines whether the steering is safely completed by monitoring the rotation angle values ​​of the wheels and the rotation angle value of the input shaft 3a. If not, it enters the safety mode to achieve closed-loop control. To achieve road feel simulation, while the steering wheel is turned, the ECU motor assembly 13 will calculate and control the output conditions of the motor in real time based on the current vehicle speed, the angle value of the input shaft 3a rotation and the torque value, so as to achieve the purpose of road feel simulation.For example, when the vehicle speed is 60 km / h and the steering wheel (i.e., input shaft 3a) input torque is 5 Nm, the ECU motor assembly 13 begins to assist rotation. As the rotation angle increases, the torque required for the ECU motor assembly 13 to assist also increases (linear change). When the vehicle wheel rotation angle limit is reached, the ECU motor assembly 13 immediately reduces the assistance until the assistance is zero. If the steering wheel angle remains unchanged, the ECU motor assembly 13 will provide appropriate counter torque according to the current vehicle speed and steering wheel angle. If the steering wheel is released (hand force is removed), the ECU motor assembly will also return to the origin at an appropriate linear speed according to the current vehicle speed and steering wheel angle.

[0028] from Figure 3 As shown, the input worm gear shaft assembly 3 is visible. The torsion bar 3d is connected to the input shaft 3a and the worm gear shaft 3i by a cylindrical pin 3b and a spline, respectively. The torsion bar 3d is made of spring steel 51CrV4. The upper part is fixedly connected to the input shaft 3a by the cylindrical pin 3b, and the lower part is interference-fitted to the worm gear shaft 3i by a spline. There is a ±5.5° relative rotatable angle between the input shaft 3a and the worm gear shaft 3i. This angle is the deformable angle of the torsion bar 3d. Once it exceeds ±5.5°, the limiting surfaces of the input shaft 3a and the worm gear shaft 3i can fit together. The sensor stator 3e and the sensor rotor 3f are also mounted on the input shaft 3a and the worm gear shaft 3i respectively, and are completed by multi-point laser welding. A gap of 0.6mm is left between the sensor stator 3e and the sensor rotor 3f. When the input shaft 3a and the worm gear shaft 3i rotate relative to each other, the sensor can convert the torque value generated by the torsion bar 3d into an electrical signal and transmit it to the ECU motor assembly 13. The O-ring 3c is a sealing and shock-absorbing structure installed between the input shaft 3a and the torsion bar 3d. The input shaft 3a and the worm gear shaft 3i are connected by a needle roller bearing 3g. Due to the limitation of radial installation size, the selection of the needle roller bearing 3g can meet the requirements of space and load. In addition, the worm gear 3h and the worm gear shaft 3i are assembled by interference fit through the inner hole of the worm gear 3h and the worm gear shaft 3i, and the pressing force is ensured by designing a suitable interference amount.

[0029] from Figure 3 As shown, end cover assembly 4 is composed of end cover 4a and end cover bearing 4b. The outer ring of end cover bearing 4b is press-fitted into the inner hole of end cover 4a using an interference fit. Furthermore, to prevent end cover bearing 4b from falling off, a stepped surface is designed on input shaft 3a. After end cover assembly 4 is assembled, there is a 1mm gap between the stepped surface and the end cover 3a. If end cover bearing 4b falls off, the stepped surface will restrain the inner ring of end cover bearing 4b, preventing it from falling off. Three φ8.5 through holes are designed on end cover 4a, and three M8 threaded holes are designed on reduction housing 6a. End cover 4a and reduction housing 6a are connected by three hexagonal flange bolts 5.

[0030] from Figure 3 , Figure 4 As shown, the reduction housing assembly 6 is composed of a reduction housing 6a, a deep groove ball bearing 6b, a four-point contact ball bearing 6c, and an adjusting bushing 6d. The outer rings of the deep groove ball bearing 6b and the four-point contact ball bearing 6c are press-fitted into the inner bore of the reduction housing 6a. The adjusting bushing 6d, through an interference fit with the reduction housing 6a within the worm chamber, acts as a buffer as the worm 8d moves away from and towards the worm wheel 3h, preventing impact noise and improving NVH performance. The adjusting bushing 6d features an elliptical bore design, allowing the worm end bearing 8e to move up and down within the adjusting bushing 6d, ensuring appropriate clearance compensation and avoiding noise caused by clearance, thus further improving NVH performance.

[0031] from Figure 4 As shown, the worm gear assembly 8 is composed of a claw coupling 8a, a riveting ring 8b, a self-aligning deep groove ball bearing 8c, a worm 8d, and a worm end bearing 8e. The inner rings of both the self-aligning deep groove ball bearing 8c and the worm end bearing 8e are press-fitted into the worm 8d with an interference fit. The worm 8d is designed with a riveting groove. The riveting ring 8b is deformed and pressed into the riveting groove by pressing against the inner ring of the self-aligning deep groove ball bearing 8c and riveting, thereby locking the self-aligning deep groove bearing 8c and the worm 8d. The head of the worm 8d can be pressed into the claw coupling 8a, thus connecting it to the motor. The self-aligning deep groove ball bearing 8c and the reduction housing 6a are fitted with a clearance. The worm screw plug 16, with its external thread engaging with the corresponding internal thread in the reduction housing 6a, is screwed in. A suitable locking torque is applied to lock the outer ring of the self-aligning deep groove ball bearing 8c, thereby locking the entire worm assembly 8 and preventing it from moving within the reduction housing 6a. Because of the presence of the self-aligning deep groove ball bearing 8c, the worm 8d can oscillate around its center of rotation. That is, the worm 8d can move up and down within the elliptical hole of the adjusting bushing 6d, following the movement of the worm end bearing 8e, thus adjusting the clearance between the worm wheel 3h and the worm 8d. Furthermore, to ensure that the steering wheel can only be rotated via the ECU motor assembly 13, the worm 8d is a single-start self-locking worm. The worm 8d can only be rotated by the motor, thereby rotating the worm wheel 3h, the input shaft 3a, and the steering wheel; it cannot be rotated by turning the steering wheel.

[0032] from Figure 4As shown, the spring plunger 7 is composed of a spring pin 7a, a spring 7b, and a plunger 7c. The spring 7b and spring pin 7a are installed inside the plunger 7c, and the spring pin 7a can extend and retract axially with the spring 7b. The spring plunger 7 can be screwed into the mating threaded hole of the reduction housing 6a through the external thread of the plunger 7c. The spring pin 7a can act on the worm end bearing 8e by adjusting the through hole of the bushing 6d. By adjusting the tightening force of the spring plunger 7, a suitable clearance value between the worm gear 3h and the worm 8d can be achieved.

[0033] In this invention, the ECU motor assembly 13 provides power and control for the entire device. To simplify the product, improve signal input / output efficiency, and reduce power voltage drop, the motor controller, i.e., the motor drive circuit and control circuit, is integrated into the tail of the motor, forming an integrated ECU motor assembly 13. Simultaneously, to improve product lifespan, ensure product stability and reliability, and enhance the accuracy of ECU control over the motor, a permanent magnet synchronous DC brushless motor with a Hall sensor disk is used. The output shaft of the ECU motor assembly 13 also has a claw coupling, which can be connected to the claw coupling 8a on the worm gear assembly 8. To prevent abnormal noise during motor start-up, stopping, and reversing, a coupling buffer pad 17 is added between the two claw couplings 8a. The ECU motor assembly 13 has connectors for power, CAN signals, and sensor signals, which can be connected to the vehicle power supply, the upper and lower connecting harness assemblies 14, and the sensor harness assembly 15, respectively, to achieve power input and signal input / output. The ECU motor assembly 13 has three φ6.5 through holes, and the reduction housing 6a has three M6 threaded holes. The ECU motor assembly 13 and the reduction housing 6a are tightened and connected by the internal hexagonal flower head screws 12.

[0034] Specifically, when the input worm gear shaft assembly 3 is first installed into the reduction housing assembly 6, after the limiting surface of the worm gear shaft 3i is in contact with the inner ring of the four-point contact ball bearing 6c, the locking nut 9 is used to lock it by engaging with the external thread of the worm gear shaft 3i, and the rivet is pressed at the rivet groove to prevent loosening.

[0035] Specifically, to limit the number of left and right rotations of the steering wheel, the limiting block 10 is rotated to the center position of the steering wheel by engaging with the worm gear shaft 3i through the central threaded hole. Then, two guide bolts 11 are screwed into the threaded holes of the reduction housing 6a through the two through holes of the limiting block 10. When we rotate the steering wheel, causing the worm gear shaft 3i to rotate, the external thread of the worm gear shaft 3i and the rotational fixation of the guide bolts 11 ensure that the limiting block 10 can only move up and down along the axial direction of the worm gear shaft 3i. For every rotation of the steering wheel, the distance the limiting block 10 moves is exactly equal to the thread pitch. By setting the distance from the limiting block 10 to the upper and lower limiting surfaces, the number of left and right rotations of the steering wheel can be limited.

[0036] Finally, after the entire product except for the lower shaft 1 is assembled, press the mating section of the lower shaft 1 into the mating hole of the input shaft 3a until the end faces are flush. Then, drill a φ5 through hole in the middle of the mating section and press the pin into the hole to ensure that the lower shaft 1 and the input shaft 3a are firmly connected and can transmit large torque.

[0037] Finally, it should be noted that the above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A steer-by-wire vehicle steering wheel road feel simulation feedback device, characterized in that: It includes a lower shaft of the tubing column (1) and a worm gear shaft assembly (3), wherein one end of the worm gear shaft assembly (3) is connected to the lower shaft of the tubing column (1) and the other end is connected to the worm gear (3h); The worm gear shaft assembly (3) includes a torsion bar (3d) and a worm gear connecting shaft (3i). One end of the torsion bar (3d) is fixedly connected to the input shaft (3a). The input shaft (3a) is fixedly connected to the lower shaft (1) of the tube column. The torsion bar (3d) is fixedly connected to the worm gear connecting shaft (3i). The input shaft (3a) is connected to the worm gear connecting shaft (3i). The connection between the input shaft (3a) and the worm gear connecting shaft (3i) is configured to have a relative rotatable angle R°. After the relative rotation of the input shaft (3a) and the worm gear connecting shaft (3i) exceeds R°, the limiting surfaces of the input shaft (3a) and the worm gear connecting shaft (3i) can fit together. It also includes a torque & angle sensor assembly and an ECU motor assembly (13). The sensor assembly includes a sensor rotor (3f) and a sensor stator (3e). The sensor rotor (3f) is fixedly mounted on the worm gear connecting shaft (3i), and the sensor stator (3e) is fixedly mounted on the input shaft (3a). The ECU motor assembly (13) is connected to the torque & angle sensor assembly through the sensor wiring harness (15). The ECU motor assembly (13) is connected to the steering gear and the vehicle ECU through the upper and lower connecting wiring harnesses (14). The output end of the ECU motor assembly (13) is connected to the worm (8d). The worm (8d) is a single-head self-locking worm. The worm (8d) meshes with the worm wheel (3h). The worm wheel (3h) is fixedly connected to the worm gear connecting shaft (3i).

2. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 1, characterized in that, It also includes an end cap assembly (4), which includes an end cap (4a) and an end cap bearing (4b). The end cap (4a) covers the connection between the lower shaft (1) of the tube column and the worm gear shaft assembly (3), and the end cap bearing (4b) is rotatably connected to the input shaft (3a).

3. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 2, characterized in that, The input shaft (3a) is designed with a stepped surface. After the end cover assembly (4) is assembled, there is a 1mm gap between it and the stepped surface. Once the end cover bearing (4b) falls off, the stepped surface will restrict the inner ring of the end cover bearing (4b) to prevent the end cover bearing (4b) from falling off.

4. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 1, characterized in that, The input shaft (3a) and the worm gear connecting shaft (3i) have two stepped connection structures. In the first structure, the input shaft (3a) and the worm gear connecting shaft (3i) are provided with limiting surfaces opposite each other, and the limiting surfaces are configured to have a relative rotation angle R°. The second structure is equipped with a needle roller bearing (3g).

5. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 4, characterized in that: R° is ±5.5°.

6. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 3, characterized in that: It also includes a reduction housing assembly (6), which consists of a reduction housing (6a), a deep groove ball bearing (6b), a four-point contact ball bearing (6c), and an adjusting bushing (6d). The outer rings of the deep groove ball bearing (6b) and the four-point contact ball bearing (6c) are fixed to the inner hole of the reduction housing 6a by an interference fit. The adjusting bushing (6d) and the reduction housing (6a) are connected to the worm gear cavity by an interference fit.

7. A steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 6, characterized in that: It also includes a worm gear assembly (8), which includes a claw coupling (8a), a rivet ring (8b), a self-aligning deep groove ball bearing (8c), a worm (8d), and a worm end bearing (8e). The inner rings of the self-aligning deep groove ball bearing (8c) and the worm end bearing (8e) are press-fitted into the worm (8d) with an interference fit. The worm (8d) is designed with a riveting groove. The rivet ring (8b) is pressed into the riveting groove by pressing against the inner ring of the self-aligning deep groove ball bearing (8c) and riveting, thereby locking the self-aligning deep groove ball bearing (8c) and the worm (8d). The head of the worm (8d) is pressed into the claw coupling (8a), thereby connecting to the motor.

8. The steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 7, characterized in that: The self-aligning deep groove ball bearing (8c) and the reduction housing (6a) are fitted with a clearance fit. The worm screw plug (16) is screwed into the reduction housing (6a) with an external thread and an internal thread. The outer ring of the self-aligning deep groove ball bearing (8c) is locked with a locking torque, thereby locking the entire worm assembly (8) and preventing the worm assembly (8) from moving inside the reduction housing (6a). The worm (8d) can swing around the swing center of the self-aligning deep groove ball bearing (8c). That is, the worm (8d) can follow the worm end bearing (8e) and move up and down in the elliptical hole of the adjusting bushing (6d), so that the clearance between the worm wheel (3h) and the worm (8d) can be adjusted.

9. A steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 8, characterized in that: It also includes a spring plunger (7) consisting of a spring pin (7a), a spring (7b) and a plunger (7c). The spring (7b) and the spring pin (7a) are installed inside the plunger (7c). The spring pin (7a) can extend and retract axially with the spring (7b). The spring plunger (7) can be screwed into the mating threaded hole of the reduction housing (6a) through the external thread of the plunger (7c). The spring pin (7a) acts on the worm end bearing (8e) through the through hole of the adjusting bushing (6d). By adjusting the tightening force of the spring plunger (7), the appropriate clearance value of the worm wheel (3h) and worm (8d) can be achieved.

10. A steer-by-wire vehicle steering wheel road feel simulation feedback device according to claim 1, characterized in that: It also includes a limit block (10), which is used to rotate the limit block (10) and the worm gear connecting shaft (3i) to the center position of the steering wheel through the threaded hole. Then, two guide bolts (11) are screwed into the threaded hole of the reduction housing (6a) through the two through holes of the limit block (10). When the steering wheel is rotated, the worm gear connecting shaft (3i) is rotated. Through the external thread of the worm gear connecting shaft (3i) and the rotation of the guide bolts (11), the limit block (10) can only move up and down in the axial direction of the worm gear connecting shaft (3i). When the steering wheel rotates one revolution, the distance that the limit block (10) moves is exactly equal to the pitch. By setting the distance between the limit block (10) and the upper and lower limit surfaces, the number of revolutions of the steering wheel can be limited.

Images