Kingpin steering system with undermount steering transmission structure, wheel angle module and vehicle

Abstract

This invention relates to the field of vehicle technology, and more particularly to a kingpin steering device with a lower-mounted steering transmission structure, a wheel angle module, and a vehicle. The kingpin steering device includes: a steering knuckle, a steering drive unit, an elastic damping assembly, and a lower control arm. The steering knuckle includes a first mounting portion, a second mounting portion, and a third mounting portion. The steering drive unit includes a steering gear, a closed reduction mechanism, and a drive shaft. The second output end of the steering gear is drively connected to the first input end of the closed reduction mechanism, and the first output end of the closed reduction mechanism is connected to the second mounting portion to drive the steering knuckle to rotate around the kingpin axis. The connecting end of the elastic damping assembly is rotatably connected to the first mounting portion. One end of the lower control arm is hinged to the third mounting portion. The advantage of this invention is that it combines a MacPherson strut suspension architecture with a motion conversion unit, overcoming the limitation of the steering angle of traditional MacPherson strut suspensions, achieving independent steering at large steering angles, and balancing suspension comfort and steering agility.

Description

Technical Field

[0001] This invention relates to the field of vehicle technology, and in particular to a kingpin steering device with a lower-mounted steering transmission structure, a wheel angle module, and a vehicle. Background Technology

[0002] With the development of new energy vehicles, intelligent driving, and drive-by-wire chassis technology, vehicle chassis systems are gradually moving towards electrification, modularization, and high integration. Automatic wheel corner modules, as a highly integrated wheel-side structure, can integrate the drive system, braking system, steering system, and suspension system near the wheels, enabling vehicles to have independent drive, independent steering, and large-angle movement capabilities. They have broad application prospects in the fields of intelligent mobile platforms and new vehicle chassis.

[0003] Currently, the kingpin steering structure in existing automatic wheel cornering modules typically adopts an integrated design of steering motor and reducer, with its axis basically coinciding with the kingpin axis. The steering motor and reducer are usually arranged vertically to reduce the lateral space occupied, but this significantly increases the suspension height and compresses the chassis ground clearance and battery placement space.

[0004] Regarding suspension design, existing corner modules mostly employ double wishbone suspension. Chinese patent publication number CN201484168U, published on May 26, 2010, entitled "An Integrated Wheel Assembly with Independent Drive, Steering, Suspension, and Braking," uses a double wishbone suspension, transmitting steering power to the upper wishbone via a telescopic universal joint and bevel gear pair. This design, by placing the steering transmission mechanism at the upper wishbone, suffers from problems such as spatial interference, increased center of gravity, weakened upper wishbone strength, and transmission nonlinearity.

[0005] Therefore, how to overcome the layout conflict between the steering transmission mechanism and the wheel-side components while avoiding the many problems of the above solutions, and how to explore the optimal matching between different suspension configurations and transmission mechanism layouts, are technical challenges that urgently need to be solved in this field. Summary of the Invention

[0006] Based on this, the present invention aims to provide a kingpin steering device with a lower-mounted steering transmission structure, a wheel angle module, and a vehicle. This solution employs a MacPherson strut suspension architecture, using a motion conversion unit to achieve the reversal and transmission of steering power, effectively decoupling steering motion from suspension vertical movement, significantly improving wheel-side structure integration and large-angle steering adaptability. The meshing tooth surfaces of the motion conversion unit always maintain unidirectional contact, effectively eliminating steering play caused by transmission backlash, while suppressing wheel tooth impact noise caused by backlash, greatly improving steering response accuracy and NVH performance.

[0007] To achieve the above objectives, the present invention provides a kingpin steering device with a lower-mounted steering transmission structure, comprising: a steering knuckle, a steering drive unit, an elastic damping assembly, and a lower control arm; the steering knuckle includes a first mounting portion, a second mounting portion, and a third mounting portion arranged sequentially from top to bottom; the steering knuckle has a kingpin axis defined by the first mounting portion and the third mounting portion; the steering drive unit is arranged along a first direction and includes a steering gear, a drive shaft, and a closed reduction mechanism; the closed reduction mechanism has a first input end and a first output end; the steering gear has a mounting end and a second output end, the mounting end being connected to the vehicle frame via a universal joint, the second output end being connected to the first input end via the drive shaft, and the first output end being connected to the second mounting portion to drive the steering knuckle to rotate around the kingpin axis; the elastic damping assembly is arranged along a second direction, which intersects the first direction, and the connecting end of the elastic damping assembly is rotatably connected to the first mounting portion; the fixed end of the elastic damping assembly is fixedly connected to the vehicle frame; the lower control arm is arranged along the first direction, and one end of the lower control arm is hinged to the third mounting portion.

[0008] Furthermore, the steering knuckle includes a steering knuckle body, a first mounting portion extending obliquely upward from the top of the steering knuckle body, a adapter provided on the first mounting portion, the adapter provided with a first connecting hole, and the connecting end of the elastic damping component rotatably connected to the first connecting hole; a third mounting portion extending from the lower part of the steering knuckle body along a first direction, the third mounting portion provided with a hinge hole for hinged with the lower control arm; and a second mounting portion extending from the end face of the steering knuckle body along the first direction, the second mounting portion provided with a second connecting hole for connecting with the steering drive unit.

[0009] Furthermore, the enclosed reduction mechanism also includes a motion conversion unit connected between the first input end and the first output end; the motion conversion unit is used to convert the rotational motion of the first input end about a first direction into the rotational motion of the first output end about the kingpin axis of the steering knuckle.

[0010] Furthermore, the motion conversion unit includes a first transmission component and a second transmission component that mesh with each other; the first transmission component is connected to the first input end, and the second transmission component is connected to the first output end.

[0011] Furthermore, the transmission ratio of the motion conversion unit is 2:1 to 10:1.

[0012] Furthermore, the first transmission member extends axially towards one end of the transmission shaft to form a first connecting portion, which is connected to the transmission shaft via a key; the second transmission member extends axially towards one end of the second mounting portion to form a second connecting portion, which is connected to the second mounting portion.

[0013] Furthermore, the first transmission component is a first bevel gear, and the second transmission component is a second bevel gear.

[0014] Furthermore, the second bevel gear is either a complete circular bevel gear or a sector bevel gear.

[0015] Furthermore, the motion conversion unit is a worm gear mechanism or a quasi-hyperboloid gear mechanism.

[0016] Furthermore, the universal joint is a telescopic universal joint.

[0017] Furthermore, the enclosed reduction mechanism also includes a reduction gearbox, with the motion conversion unit disposed within the reduction gearbox; the reduction gearbox includes an upper housing and a lower housing, with a receiving cavity formed between the upper and lower housings, and the motion conversion unit disposed within the receiving cavity; a first through hole is provided on the side of the reduction gearbox facing the drive shaft, and a second through hole is provided on the side of the reduction gearbox facing the steering knuckle; a first connecting part at least partially passes through the first through hole and is connected to the drive shaft; a second connecting part at least partially passes through the second through hole and is rotatably connected to a second mounting part; a first sealing element is provided between the first through hole and the first connecting part; a second sealing element is provided between the second through hole and the second connecting part; the first sealing element and / or the second sealing element is an oil seal, a labyrinth seal, or a combined sealing structure.

[0018] Furthermore, the steering gear is an electric motor, hydraulic motor, or pneumatic motor; the electric motor integrates a reducer.

[0019] Furthermore, it also includes a steering angle sensor and an attitude sensor; the steering angle sensor is installed at the first output end or the second mounting part of the steering knuckle to detect the rotation angle of the steering knuckle in real time; the attitude sensor is installed on the steering knuckle to collect the spatial attitude data of the steering knuckle.

[0020] A wheel corner module includes a wheel assembly and a kingpin steering device with a steering transmission structure as described above; the wheel assembly includes a wheel, a hub motor, and a brake; the hub motor is disposed in the hub of the wheel, and the steering knuckle is connected to the hub motor; the brake includes a brake disc and a caliper, the brake disc is connected to the hub motor, and the caliper is connected to the steering knuckle.

[0021] A vehicle comprising at least two wheel corner modules as described above.

[0022] Furthermore, the four wheel corner modules are respectively located at the front left, front right, rear left, and rear right positions of the vehicle, enabling independent four-wheel drive and independent steering.

[0023] Furthermore, the vehicle controller is electrically connected to the steering drive unit of each wheel angle module; the vehicle controller is used to independently control the steering angle and attitude of each wheel, and to coordinate the vehicle's normal steering, stationary steering, lateral translation, and diagonal driving modes.

[0024] Compared with existing technologies, inventions and creations can achieve the following beneficial effects:

[0025] The combination of MacPherson strut suspension architecture and steering drive unit not only retains the inherent advantages of MacPherson strut suspension such as simple structure, small space occupation, strong load-bearing capacity and low cost, but also realizes the reversal and transmission of steering power through motion conversion unit, so as to effectively decouple steering motion from suspension vertical bounce, overcome the shortcomings of traditional MacPherson strut suspension in steering angle limitation, realize independent steering at large turning angle, and take into account both suspension comfort and steering agility.

[0026] Placing the steering drive unit in the area below the steering knuckle and close to the lower control arm can significantly reduce the center of gravity height of the wheel-side structure, thereby reducing vehicle roll tendency and improving handling stability. At the same time, this layout frees up space above the wheel arch, which is beneficial for the battery pack arrangement and chassis flattening design of new energy vehicles.

[0027] The lower control arm and the steering drive unit are arranged in the same direction, and the steering driving force and the guiding force are in the same direction. The kinematic relationship is simple, which effectively reduces the interference of the additional torque on the deceleration mechanism. At the same time, this layout can ensure that the lateral constraint force provided by the lower control arm is stable, so that the tooth surface of the bevel gear pair is always in contact, eliminating the steering free play caused by transmission backlash, and significantly improving the steering response accuracy.

[0028] The gearbox adopts a split upper and lower housing design. When inspecting or replacing the internal motion conversion unit, it is not necessary to disassemble the gearbox from the steering knuckle as a whole. Only the upper and lower housings need to be separated to access the internal motion conversion unit, which significantly reduces the difficulty of maintenance.

[0029] Both through holes of the gearbox are equipped with sealing structures to prevent the intrusion of external pollutants such as mud and water vapor, while avoiding leakage of internal lubricating medium, ensuring long-term stable operation of the mechanism and adapting to harsh road conditions.

[0030] The motion conversion unit can be selected from various structures such as bevel gears, worm gears, and hypoid gears, combined with an adjustable transmission ratio of 2:1 to 10:1, which can be flexibly selected according to the vehicle's load, steering torque, speed and operating conditions; the worm gear mechanism also has a reverse self-locking characteristic, which can improve steering stability when parking and driving straight.

[0031] The steering angle sensor is located at the first output end, which can avoid the influence of transmission backlash on angle detection, realize closed-loop control of steering angle, and improve steering accuracy. The attitude sensor is installed on the steering knuckle to detect the spatial attitude of the steering knuckle in real time, obtain the attitude changes during wheel bounce, and provide data support for suspension kinematic analysis and steering control strategy optimization. Attached Figure Description

[0032] The accompanying drawings, which form part of the invention, are used to provide a further understanding of the invention. The illustrative embodiments of the invention and their descriptions are used to explain the invention and do not constitute an undue limitation of the invention. In the drawings:

[0033] Figure 1 This is a schematic diagram of the structure of the wheel corner module provided in an embodiment of the present invention;

[0034] Figure 2 This is a schematic diagram of the structure of the kingpin steering device with a lower steering transmission structure provided in an embodiment of the present invention;

[0035] Figure 3 This is a schematic diagram of the steering knuckle provided according to an embodiment of the present invention;

[0036] Figure 4 This is a schematic diagram of the steering gear and motion conversion unit provided according to an embodiment of the present invention;

[0037] Figure 5 This is a structural schematic diagram of a gearbox provided according to an embodiment of the present invention.

[0038] The reference numerals in the accompanying drawings include: 10, wheel assembly; 20, kingpin steering device with lower steering transmission structure; 21, steering knuckle; 211, steering knuckle body; 212, first mounting part; 213, second mounting part; 214, third mounting part; 215, first fixing part; 216, second fixing part; 217, hinge hole; 218, third fixing part; 219, adapter; 22, steering drive unit; 221, steering gear; 222, drive shaft; 223, reduction gearbox; 2231, upper housing; 2232, lower housing; 2233, first through hole; 2234, second through hole; 224, motion conversion unit; 2241, first bevel gear; 2242, second bevel gear; 2243, first connecting part; 2244, second connecting part; 23, elastic damping assembly; 24, lower control arm; 25, telescopic universal joint. Detailed Implementation

[0039] To make the purpose, technical solution, and advantages of the invention clearer, the invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are for illustrative purposes only and do not constitute a limitation on the invention.

[0040] It should be noted that, where there is no conflict, the embodiments and features in the embodiments of the invention can be combined with each other.

[0041] In the description of an invention, it should be understood that the terms "center," "longitudinal," "lateral," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," and "outer," etc., indicating orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings, are only for the convenience of describing the invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the invention. Furthermore, the terms "first," "second," etc., are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature specified with "first," "second," etc., may explicitly or implicitly include one or more of that feature. In the description of an invention, unless otherwise stated, "a plurality of" means two or more.

[0042] In the description of the invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in the invention based on the specific circumstances.

[0043] The invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0044] like Figures 1 to 5 As shown, a wheel corner module includes a wheel assembly 10 and a kingpin steering device 20 mounted on the lower part of the steering transmission structure. The kingpin steering device 20 includes a steering knuckle 21, a steering drive unit 22, an elastic damping assembly 23, and a lower control arm 24. The elastic damping assembly 23 is connected to the upper part of the steering knuckle 21; the lower control arm 24 is hinged to the lower part of the steering knuckle 21. The steering drive unit 22 is connected to the steering knuckle 21 and is disposed close to the lower control arm 24. The steering drive unit 22 drives the wheel assembly 10 to steer via the steering knuckle 21.

[0045] Specifically, the wheel assembly 10 includes a wheel, a hub motor, and a brake; the hub motor is built into the rim of the wheel, and the steering knuckle 21 is fixedly connected to the hub motor. The brake includes a brake disc and a caliper; the brake disc is fixedly connected to the hub motor, and the caliper is fixedly mounted on the steering knuckle 21 to realize the wheel braking function.

[0046] The steering knuckle 21 includes a steering knuckle body 211, a first mounting part 212, a second mounting part 213, a third mounting part 214, a first fixing part 215, and a second fixing part 216. The first mounting part 212, the second mounting part 213, and the third mounting part 214 are arranged sequentially from top to bottom along the kingpin axis.

[0047] The steering knuckle body 211 has a hub bearing hole at its center for accommodating and positioning the hub bearing. Multiple fastening holes are evenly distributed circumferentially around the hub bearing hole; fasteners pass through these holes to lock and fix the hub bearing to the steering knuckle body 211. The fastening holes are not shown in the diagram.

[0048] In this embodiment, the side of the steering knuckle body 211 facing the wheel is the inner side, and the side facing away from the wheel is the outer side. The width direction of the vehicle is defined as the first direction, and the height direction of the vehicle is defined as the second direction.

[0049] The first mounting portion 212 extends obliquely upward and outward from the top of the steering knuckle body 211. An adapter 219 is provided on the first mounting portion 212, and a first connecting hole is provided on the adapter 219. The connecting shaft (connecting end) of the elastic damping assembly 23 is rotatably connected to the first connecting hole via a bearing. The fixed end of the elastic damping assembly 23 is fixedly connected to the vehicle frame.

[0050] The third mounting part 214 extends from the lower part of the steering knuckle body 211 toward the first direction. The third mounting part 214 is provided with a hinge hole 217. The center of the hinge hole 217 and the center of the first connecting hole form the kingpin axis of the steering knuckle.

[0051] The second mounting portion 213 extends from the outer end face of the steering knuckle body 211 toward the first direction and is located below the hub bearing hole, close to the third mounting portion 214. The distance between the second mounting portion 213 and the first mounting portion 212 is greater than the distance between the second mounting portion and the third mounting portion 214. The second mounting portion 213 has a second connecting hole, the center of which is located on the kingpin axis. The output end (second output end) of the steering drive unit 22 is fixedly connected to the second connecting hole.

[0052] The first fixing part 215 and the second fixing part 216 are arranged on the steering knuckle body 211 along the longitudinal direction of the vehicle, and they extend in opposite directions respectively. A third fixing part 218 is provided below the third mounting part 214, and a fourth fixing part extends upward from the top of the steering knuckle body 211. The first fixing part 215, the second fixing part 216, the third fixing part 218, and the fourth fixing part are all used for fixed assembly with the hub motor, realizing the integrated connection between the steering knuckle 21 and the hub motor.

[0053] The steering drive unit 22 and the lower control arm 24 are both arranged along the first direction (vehicle width direction), and the elastic damping assembly 23 is arranged along the second direction (vehicle height direction).

[0054] In this embodiment, the drive axis of the steering drive unit 22 is consistent with the first direction, ensuring that the steering power transmission direction is consistent with the structural layout direction.

[0055] Specifically, the steering drive unit 22 includes a steering gear 221, a drive shaft 222, and a closed reduction gear mechanism. The steering gear 221 includes a steering motor, which integrates a planetary gear reducer. The output end (second output end) of the planetary gear reducer is connected to the first input end of the closed reduction gear mechanism via the drive shaft 222. The mounting end of the steering motor (i.e., the mounting end of the steering gear 221 housing) is connected to the vehicle frame via a telescopic universal joint 25. The first output end of the closed reduction gear mechanism is connected to the second mounting portion 213 to drive the steering knuckle 21 to rotate around the kingpin axis.

[0056] It should be noted that the specific connection method between the mounting end of the steering gear 221 housing and the telescopic universal joint 25 is not specifically limited, as long as it can enable the steering drive unit 22 to perform axial extension and retraction compensation and follow-up through the telescopic universal joint 25 when the suspension bounces.

[0057] The telescopic universal joint 25 is used to compensate for angular deviations and axial displacements between the steering gear 221 and the vehicle frame caused by suspension bounce or assembly tolerances.

[0058] During vehicle operation, the steering knuckle 21 bounces with road surface excitation, and the steering gear 221, through the telescopic universal joint 25, generates spatial displacement and angular sway relative to the frame as the suspension moves. The telescopic universal joint 25 can adapt to changes in the angle between the steering gear 221 and the frame, avoiding interference or jamming caused by rigid connection, while efficiently transmitting the rotational torque output by the steering gear 221 to the reduction mechanism.

[0059] The telescopic universal joint 25 consists of a universal joint body and a spline telescopic sleeve, combining universal drive and axial telescopic functions. When the suspension moves up and down, the linear distance between the steering gear 221 and the vehicle frame changes. The telescopic universal joint 25 automatically compensates for the length change through the axial sliding of the spline pair, while simultaneously compensating for angular deviations through the universal joint body. This structure is suitable for vehicles with large suspension travel and high requirements for axial compensation capabilities.

[0060] In some embodiments, the steering mechanism 221 is a hydraulic motor or a pneumatic motor.

[0061] The enclosed reduction mechanism includes a reduction gearbox 223, a motion conversion unit 224, a first input end, and a first output end. The motion conversion unit 224 is disposed inside the reduction gearbox 223 and is connected between the first input end and the first output end. The motion conversion unit 224 is used to convert the rotational motion of the first input end about a first direction into the rotational motion of the first output end about the kingpin axis of the steering knuckle 21.

[0062] The motion conversion unit 224 includes a first transmission member and a second transmission member that mesh with each other; the transmission ratio of the motion conversion unit 224 is 2:1 to 10:1. The first transmission member is connected to the transmission shaft 222 via a key, and the second transmission member is connected to the second mounting part 213.

[0063] In this embodiment, the first connecting part 2243 is connected to the drive shaft 222 via a spline.

[0064] Example 1 of motion conversion unit 224:

[0065] The first transmission component is a first bevel gear 2241, and the second transmission component is a second bevel gear 2242. The first bevel gear 2241 extends axially towards the end of the transmission shaft 222 to form a first connecting portion 2243 (i.e., the first input end of the enclosed reduction mechanism), and the first connecting portion 2243 is connected to the transmission shaft 222. The second bevel gear 2242 extends axially towards the end of the second mounting portion 213 to form a second connecting portion 2244 (i.e., the first output end of the enclosed reduction mechanism), and the second connecting portion 2244 is connected to the second mounting portion 213.

[0066] In this embodiment, the second bevel gear 2242 is a complete circular bevel gear. The first bevel gear 2241 and the first connecting part 2243 are integrally formed, and the second bevel gear 2242 and the second connecting part 2244 are integrally formed.

[0067] In other embodiments, the second bevel gear 2242 is a sector bevel gear. Both ends of the sector bevel gear are provided with limiting portions, which are used to limit the rotation angle of the sector bevel gear to achieve steering limitation.

[0068] The transmission ratio between the second bevel gear 2242 and the first bevel gear 2241 is 2:1 to 10:1. The choice of transmission ratio directly affects the output torque and response speed of the steering system. The smaller the transmission ratio (e.g., 2:1), the smaller the reduction in the output speed of the steering motor after deceleration, and the faster the wheel angle response speed, which is suitable for high-speed driving conditions with high steering sensitivity; the larger the transmission ratio (e.g., 8:1), the greater the amplification of the output torque of the steering motor, and the greater the steering torque that the wheels can obtain, which is suitable for large-angle low-speed steering or stationary steering conditions that require overcoming greater ground resistance.

[0069] Those skilled in the art can select a suitable gear ratio within the above range based on vehicle type, steering motor parameters, and target steering performance. As a preferred example, this embodiment configures the gear ratio to 4:1 to balance steering response speed and steering torque requirements, thereby achieving balanced steering performance.

[0070] The bevel gear pair has the advantages of compact structure, high transmission efficiency, and smooth reversing. The first bevel gear 2241 and the second bevel gear 2242 are perpendicular to each other, enabling the steering gear 221 to convert its rotational motion around the first direction into the steering knuckle 21's rotational motion around the kingpin axis, achieving a 90° power reversal with high transmission efficiency and low power loss. Simultaneously, the lateral force generated by the lower control arm 24 and the steering drive unit 22, arranged in the same direction, keeps the bevel gear teeth surfaces in contact, further ensuring the full utilization of its transmission efficiency.

[0071] Example 2 of motion conversion unit 224:

[0072] The only difference between this embodiment and Embodiment 1 is the structure of the motion conversion unit 224. In this embodiment, the motion conversion unit 224 adopts a worm gear mechanism and is integrally arranged within the receiving cavity of the reduction gearbox 223; the worm gear is coaxially and fixedly connected to the second connecting part 2244, and the worm is coaxially and fixedly connected to the first connecting part 2243. The worm gear mechanism has the characteristics of large transmission ratio and smooth operation, and is suitable for heavy-duty vehicles and steering scenarios requiring self-locking.

[0073] Worm gear mechanisms offer advantages such as a large transmission ratio, compact structure, and excellent self-locking characteristics. Within the same spatial dimensions, worm gear mechanisms can achieve a larger transmission ratio (e.g., 10:1 or higher) than bevel gear pairs, resulting in greater steering output torque. This makes them particularly suitable for heavy-duty vehicles or scenarios requiring high steering torque at large steering angles. Furthermore, worm gear mechanisms possess a reverse self-locking characteristic; when the steering motor stops operating, the wheels maintain their current position without being affected by ground reaction forces, improving steering stability during parking and straight-line driving. Worm gear mechanisms also operate smoothly with minimal impact, contributing to improved NVH performance of the steering system.

[0074] Example 3 of motion conversion unit 224:

[0075] The motion conversion unit 224 can also adopt a quasi-hyperboloid gear mechanism, which can be flexibly selected according to the load, steering torque and speed requirements of different vehicles, thus expanding the application scenarios of this device.

[0076] The hypoid gear mechanism boasts advantages such as high load-bearing capacity, smooth meshing, and high transmission efficiency. Compared to ordinary bevel gear pairs, hypoid gears have a larger tooth surface contact area, enabling them to withstand higher torque and impact loads, making them suitable for vehicles with heavy loads or operating in harsh environments. The offset design of the hypoid gear ensures that the input and output shafts are not in the same plane, providing greater flexibility in the internal spatial layout of the reduction gearbox 223 and facilitating the optimization of its overall structure. Furthermore, the hypoid gear exhibits a high degree of meshing overlap and low operating noise, contributing to improved NVH performance of the steering system.

[0077] This device employs a two-stage reduction gear layout: the first stage is the reducer integrated within the steering gear 221, and the second stage is the motion conversion unit 224 within the enclosed reduction mechanism. Compared to a single-stage reduction scheme, this layout has the following advantages:

[0078] Large overall gear ratio: Two-stage reduction can achieve a larger overall gear ratio, meeting the steering torque requirements of large-angle turning on the spot or heavy vehicles.

[0079] Flexible motor selection: High-speed, low-torque, low-cost small steering motors can be used, reducing motor cost and size.

[0080] Compact spatial layout: The transmission ratio is distributed in two dimensions (axial and radial), avoiding the large-diameter gears required for a single-stage large reduction ratio and improving the integration of the wheel-side structure.

[0081] NVH performance optimization: The two-stage reduction disperses the gear meshing frequency, and combined with the vibration isolation effect of the drive shaft 222, it effectively reduces the operating noise and vibration of the steering system.

[0082] High reliability: The two-stage reduction units serve as backups for each other. Even if one stage experiences slight wear, it can still maintain basic steering function, thus improving the system's fault tolerance.

[0083] The gearbox 223 includes an upper housing 2231 and a lower housing 2232, with a receiving cavity formed between the upper housing 2231 and the lower housing 2232, and the motion conversion unit 224 is disposed in the receiving cavity.

[0084] The gearbox 223 has a first through hole 2233 on the side facing the drive shaft 222, and a first bearing is installed inside it; the gearbox 223 has a second through hole 2234 on the side facing the steering knuckle 21, and a second bearing is installed inside it.

[0085] The first connecting part 2243 passes through the first bearing at least partially and is connected to the drive shaft 222; the second connecting part 2244 passes through the second bearing at least partially and is connected to the second connecting hole by a key.

[0086] In this embodiment, the second connecting part 2244 is provided with threads, and it is locked and fixed by a nut after passing through the second connecting hole.

[0087] A first sealing element is provided between the first through hole 2233 and the first connecting part 2243. A second sealing element is provided between the second through hole 2234 and the second connecting part 2244. The first sealing element and / or the second sealing element is an oil seal, a labyrinth seal, or a combined sealing structure.

[0088] With the above structure, the gearbox 223 not only serves as the housing for the motion conversion unit 224, but its split-type housing design also facilitates the installation and maintenance of the motion conversion unit 224. The seals at the through-holes prevent the intrusion of external contaminants, ensure reliable internal lubrication, and effectively extend the service life of the device.

[0089] The kingpin steering device 20 with its steering transmission structure located at the bottom also includes a sensor assembly, which includes a steering angle sensor and an attitude sensor.

[0090] A steering angle sensor is located at the first output end of the enclosed reduction gear (i.e., the second connection 2244) or the second mounting part 213 of the steering knuckle 21, and is used to detect the rotation angle of the steering knuckle 21 in real time. This sensor can be an absolute encoder, a rotary transformer, or a Hall angle sensor. The steering angle sensor feeds back the detected actual steering angle signal to the vehicle controller, compares it with the target steering angle command, and forms a closed-loop steering angle control, thereby improving steering accuracy and response speed.

[0091] Preferably, the steering angle sensor is an absolute encoder, which is installed on the second connecting part 2244 to directly measure the output angle of the deceleration mechanism, thus avoiding the influence of transmission backlash on the angle detection accuracy.

[0092] The attitude sensor employs a MEMS inertial measurement unit (IMU), integrating a three-axis accelerometer and a three-axis gyroscope, and is mounted on the steering knuckle 21. It is used to detect the attitude angles of the steering knuckle 21 in space in real time, including but not limited to parameters such as roll angle, pitch angle, and yaw angle. This embodiment uses an IMU, but broadly speaking, a tilt sensor or accelerometer can also be used to achieve similar functionality.

[0093] By monitoring the spatial attitude changes of the steering knuckle 21, the relative motion relationship between the steering knuckle, drive shaft 222, and motion conversion unit 224 during wheel hopping can be obtained. This data can be used to monitor the suspension hopping amplitude, identify wheel attitude deviations caused by road surface excitation or assembly errors, and provide support for suspension kinematic analysis and steering control strategy optimization.

[0094] It should be noted that since the attitude sensor is mounted on the steering knuckle 21 (which is an unsprung mass), it detects the spatial attitude of the steering knuckle itself, rather than the vehicle body attitude. Compared to the vehicle body mounting method, the steering knuckle mounting can more directly and quickly sense the attitude changes of the wheel assembly 10, accurately reflect the impact of road excitation on wheel movement, and effectively reduce the phase lag of the control signal due to suspension transmission delay, thereby improving the real-time performance of the control response.

[0095] A vehicle includes at least two wheel corner modules as described above and a vehicle controller. In this embodiment, four wheel corner modules are respectively disposed at the front left, front right, rear left, and rear right positions of the vehicle, enabling independent drive and independent steering of all four wheels. The vehicle controller is electrically connected to the steering drive unit 22 of each wheel corner module to control the independent steering of each wheel, thereby enabling front wheel steering, rear wheel steering, four-wheel steering, stationary steering, translation mode, or diagonal driving mode.

[0096] In summary, the MacPherson strut kingpin steering device, wheel angle module, and vehicle provided by this invention have the following advantages:

[0097] This invention combines a MacPherson strut suspension architecture with a motion conversion unit 224. It retains the inherent advantages of the MacPherson strut suspension, such as simple structure, small space occupation, strong load-bearing capacity, and low cost. At the same time, the motion conversion unit 224 realizes the reversal and transmission of steering power, effectively decoupling the steering motion from the vertical jump of the suspension. This overcomes the shortcomings of the traditional MacPherson strut suspension in terms of steering angle limitation, realizes independent steering at large steering angles, and balances suspension comfort and steering agility.

[0098] By placing the steering drive unit 22 in the area below the steering knuckle 21 near the lower control arm 24, the center of gravity height of the wheel-side structure can be significantly reduced, thereby reducing vehicle roll tendency and improving handling stability. At the same time, this layout frees up space above the wheel arch, which is beneficial for the battery pack arrangement and chassis flattening design of new energy vehicles. In addition, the output end of the steering drive unit 22 acts directly on the kingpin axis, shortening the power transmission path and improving steering response efficiency. Moreover, it is installed in the lower area of ​​the steering knuckle 21 where the stiffness is the greatest, which helps to suppress vibration transmission and improve the overall vehicle comfort. Ultimately, it balances independent steering capability at large turning angles with suspension comfort.

[0099] The lower control arm 24 and the steering drive unit 22 are arranged in the same direction, and the steering driving force and the guiding force are in the same direction. The kinematic relationship is simple and effectively reduces the interference of the additional torque on the deceleration mechanism. At the same time, this layout can ensure that the lateral constraint force provided by the lower control arm 24 is stable, so that the tooth surface of the bevel gear pair is always in contact, eliminating the steering free travel caused by the transmission backlash and significantly improving the steering response accuracy.

[0100] The gearbox 223 adopts a split upper and lower housing design. When inspecting or replacing the internal motion conversion unit 224, it is not necessary to completely disassemble the gearbox 223 from the steering knuckle 21. Only the upper housing 2231 and the lower housing 2232 need to be separated to access the internal motion conversion unit 224, which significantly reduces the difficulty of maintenance.

[0101] The gearbox 223 has two through holes equipped with a sealing structure, which can prevent external pollutants such as mud and water vapor from entering, while avoiding leakage of internal lubricating medium, ensuring long-term stable operation of the mechanism and adapting to harsh road conditions.

[0102] The motion conversion unit 224 can be selected from various structures such as bevel gears, worm gears, and hypoid gears, combined with an adjustable transmission ratio of 2:1 to 10:1, which can be flexibly selected according to the vehicle load, steering torque, speed and operating conditions; the worm gear mechanism also has a reverse self-locking characteristic, which can improve the steering stability when parking and driving straight.

[0103] The steering gear 221 is connected to the vehicle frame via a telescopic universal joint 25, which can compensate for the angular deviation and axial displacement caused by suspension bounce and avoid motion interference.

[0104] The steering angle sensor and attitude sensor are respectively arranged at the first output end and the steering knuckle 21, which can avoid the influence of transmission backlash on angle detection and quickly collect wheel attitude information. The steering angle closed-loop control improves steering accuracy, and the wheel attitude data provides support for vehicle stability control such as rollover prevention, drive force distribution, and active suspension adjustment.

[0105] The vehicle adopts a four-wheel independent drive and independent steering structure, which can realize multiple driving modes such as front wheel steering, rear wheel steering, four-wheel steering, turning on the spot, lateral movement, and diagonal driving, greatly improving the vehicle's maneuverability.

[0106] The specific embodiments described above do not constitute a limitation on the scope of protection of this invention. Those skilled in the art should understand that various modifications, combinations, sub-combinations, and substitutions can be made according to design requirements and other factors. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this invention should be included within the scope of protection of this invention.

Claims

1. A kingpin steering device with a lower-mounted steering transmission structure, characterized in that, include: Steering knuckle, steering drive unit, elastic damping assembly, and lower control arm; The steering knuckle includes a first mounting portion, a second mounting portion, and a third mounting portion arranged sequentially from top to bottom; the steering knuckle has a kingpin axis defined by the first mounting portion and the third mounting portion. The steering drive unit is arranged along a first direction. The steering drive unit includes a steering gear, a drive shaft, and a closed reduction mechanism. The closed reduction mechanism has a first input end and a first output end. The steering gear has a mounting end and a second output end. The mounting end is connected to the vehicle frame via a universal joint. The second output end is connected to the first input end via the drive shaft. The first output end is connected to the second mounting part to drive the steering knuckle to rotate around the kingpin axis. The elastic damping component is arranged along a second direction, which intersects with the first direction. The connecting end of the elastic damping component is rotatably connected to the first mounting part. The fixed end of the elastic damping component is fixedly connected to the vehicle frame. The lower control arm is arranged along the first direction, and one end of the lower control arm is hinged to the third mounting part.

2. The kingpin steering device with a lower-mounted steering transmission structure according to claim 1, characterized in that, The steering knuckle includes a steering knuckle body, the first mounting portion extends obliquely upward from the top of the steering knuckle body, the first mounting portion is provided with an adapter, the adapter is provided with a first connecting hole, and the connecting end of the elastic damping component is rotatably connected to the first connecting hole. The third mounting portion extends from the lower part of the steering knuckle body along the first direction, and the third mounting portion is provided with a hinge hole for hinged with the lower control arm; The second mounting portion extends from the end face of the steering knuckle body along the first direction, and the second mounting portion is provided with a second connecting hole for connecting to the steering drive unit.

3. The kingpin steering device with a lower-mounted steering transmission structure according to claim 1, characterized in that, The enclosed deceleration mechanism also includes a motion conversion unit connected between the first input end and the first output end; The motion conversion unit is used to convert the rotational motion of the first input end about the first direction into the rotational motion of the first output end about the kingpin axis of the steering knuckle.

4. The kingpin steering device with a lower-mounted steering transmission structure according to claim 3, characterized in that, The motion conversion unit includes a first transmission component and a second transmission component that mesh with each other. The first transmission component is connected to the first input terminal, and the second transmission component is connected to the first output terminal.

5. The kingpin steering device with a lower-mounted steering transmission structure according to claim 4, characterized in that, The transmission ratio of the motion conversion unit is 2:1 to 10:

1.

6. The kingpin steering device with a lower-mounted steering transmission structure according to claim 4, characterized in that, The first transmission member extends axially toward one end of the transmission shaft to form a first connecting portion, which is connected to the transmission shaft by a key; the second transmission member extends axially toward one end of the second mounting portion to form a second connecting portion, which is connected to the second mounting portion.

7. The kingpin steering device with a lower-mounted steering transmission structure according to claim 4, characterized in that, The first transmission component is a first bevel gear, and the second transmission component is a second bevel gear.

8. The kingpin steering device with a lower-mounted steering transmission structure according to claim 7, characterized in that, The second bevel gear is a complete circular bevel gear or a sector bevel gear.

9. The kingpin steering device with a lower-mounted steering transmission structure according to claim 3, characterized in that, The motion conversion unit is a worm gear mechanism or a quasi-hyperboloid gear mechanism.

10. The kingpin steering device with a lower-mounted steering transmission structure according to claim 1, characterized in that, The universal joint is a telescopic universal joint.

11. The kingpin steering device with a lower-mounted steering transmission structure according to claim 6, characterized in that, The enclosed deceleration mechanism also includes a reduction gearbox, and the motion conversion unit is disposed inside the reduction gearbox; The gearbox includes an upper housing and a lower housing, and a receiving cavity is formed between the upper housing and the lower housing. The motion conversion unit is disposed in the receiving cavity. The gearbox has a first through hole on the side facing the drive shaft and a second through hole on the side facing the steering knuckle. The first connecting portion passes at least partially through the first through hole and is connected to the drive shaft; the second connecting portion passes at least partially through the second through hole and is rotatably connected to the second mounting portion. A first sealing element is provided between the first through hole and the first connecting part; a second sealing element is provided between the second through hole and the second connecting part; The first seal and / or the second seal are oil seals, labyrinth seals, or combined seal structures.

12. The kingpin steering device with a lower-mounted steering transmission structure according to claim 1, characterized in that, The steering gear is an electric motor, hydraulic motor, or pneumatic motor; the electric motor integrates a reducer.

13. The kingpin steering device with a lower-mounted steering transmission structure according to claim 1, characterized in that, It also includes a steering angle sensor and an attitude sensor; The steering angle sensor is installed at the first output end or the second mounting part of the steering knuckle, and is used to detect the rotation angle of the steering knuckle in real time; the attitude sensor is installed on the steering knuckle and is used to collect the spatial attitude data of the steering knuckle.

14. A wheel corner module, characterized in that, Includes a wheel assembly, and a kingpin steering device with a lower steering transmission structure as described in any one of claims 1 to 13; The wheel assembly includes a wheel, a hub motor, and a brake; the hub motor is disposed inside the hub of the wheel, and the steering knuckle is connected to the hub motor; The brake includes a brake disc and a caliper, the brake disc being connected to the hub motor and the caliper being connected to the steering knuckle.

15. A vehicle, characterized in that, It includes at least two wheel corner modules as described in claim 14.

16. The vehicle according to claim 15, characterized in that, It includes four wheel corner modules, which are respectively located at the front left, front right, rear left, and rear right positions of the vehicle, enabling independent drive and independent steering of the four wheels.

17. The vehicle according to claim 16, characterized in that, It also includes a vehicle controller, which is electrically connected to the steering drive unit of each wheel angle module; the vehicle controller is used to independently control the steering angle and attitude of each wheel, and to coordinate the vehicle's normal steering, stationary steering, lateral translation and diagonal driving modes.

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