Longitudinal arm suspension structure with hub motor

Abstract

The invention relates to the technical field of automobile part structures, in particular to a trailing arm suspension structure with a hub motor. Comprising a wheel assembly, a hub motor fixed to the wheel assembly, a steering knuckle fixed to the hub motor and a steering angle module used for driving the steering knuckle to rotate around the Z-direction axis, and further comprises an upper trailing arm assembly and a lower trailing arm assembly, the upper trailing arm assembly extends in the X direction, one end of the upper trailing arm assembly is hinged to the steering angle module in the mode that the one end can rotate around the Y-direction axis, and the other end of the lower trailing arm assembly is hinged to the steering angle module in the mode that the other end can rotate around the Y-direction axis. The other end of the connecting rod can rotate around the Y-direction axis and is connected to the frame; the lower trailing arm assembly is located below the upper trailing arm assembly and extends in the X direction, one end of the lower trailing arm assembly is hinged to the steering knuckle in a universal rotation mode, and the other end of the lower trailing arm assembly is connected to the vehicle frame in a mode that the other end of the lower trailing arm assembly can rotate around the Y-direction axis. The trailing arm suspension is simple in structure and meets the use requirements of driving, parking and the like of future vehicles on various complex road conditions, and the double-trailing-arm structure is small in occupied space in the X direction and convenient to arrange.

Description

Technical Field

[0001] The present invention relates to the technical field of automobile component structures, and in particular to a trailing arm suspension structure with a hub motor. Background Art

[0002] Existing vehicles basically use bridge motors for steering, and the suspension adopts McPherson, double wishbone, multi-link, etc., which have problems such as mutual coupling between the suspension, steering, and transmission systems, excessive tire envelope during movement, large space occupation, and difficult layout. As a result, the vehicle has a large turning radius, making it difficult for the vehicle to drive and steer in narrow places, and the suspension movement range is limited, affecting the improvement of the vehicle's smoothness, making it difficult to meet some special usage requirements of the vehicle.

[0003] Some new vehicles use in-wheel motor differential steering, such as a prior art single-trailing-arm in-wheel motor drive module. This module includes a trailing-arm mounting bracket, a trailing arm, a hub motor, cables, brakes, a cooling water pipe, a fastening screw, and a spring connecting pin. The trailing-arm mounting bracket has a threaded interface, and the trailing-arm pin end couples with the trailing-arm mounting bracket to form a revolute pair. The hub motor is mounted to the trailing-arm interface via a fastening screw. The cables and cooling water pipe pass through the trailing-arm cavity and exit at the trailing-arm bracket end. The motor cooling water pipe and cable are introduced through an opening at the far end of the trailing arm and exit through an opening on the trailing-arm spring mounting side near the trailing-arm mounting bracket. This module utilizes a hollow, thin-walled trailing-arm structure to integrate the hub motor, brakes, cables, and pipelines, achieving a modular trailing-arm integration of the drive system. This module offers a large vehicle bouncing stroke, and the trailing arm is suitable for wide-range swinging, providing greater suspension lateral stiffness and providing the technical guarantee for vehicles to navigate ultra-high geometric obstacles.

[0004] However, this module also has some problems: 1. The module adopts a single trailing arm in the middle, which is limited by the tire envelope and cannot achieve tire steering. Therefore, it can only be arranged on non-steering wheels or use differential steering. When using the differential steering of the hub motor, there are problems such as single steering mode, low transmission efficiency, and great damage to the tires. When the vehicle is driving on poor roads, the differential may suffer excessive wear, resulting in its function being reduced and losing the ability to adjust the speed difference, and even causing travel failure. Moreover, when the vehicle is driving at high speed, the speed difference between the drive wheels on both sides may affect the balance of the vehicle, resulting in reduced vehicle stability and posing a safety risk. 2. The forces in all directions are transmitted to the vehicle body or frame by a single trailing arm, resulting in high stress on the trailing arm; 3. The trailing arm is connected to the frame or body through a single fulcrum. When the tire is subjected to x- and y-direction forces, the strain will be amplified through the trailing arm, causing the vehicle to yaw and vibrate. 4. The integrated design of the hollow thin-walled longitudinal arm structure reduces system reliability and makes maintenance inconvenient.

[0005] Therefore, there is an urgent need to develop a hub motor trailing arm suspension structure that can solve the above problems. Summary of the Invention

[0006] The purpose of this application is to address the deficiencies of the above-mentioned background technology and to provide a trailing arm suspension structure with a hub motor.

[0007] The technical solution of the present application is: a trailing arm suspension structure with a hub motor, comprising a wheel assembly, a hub motor fixed to the wheel assembly, a steering knuckle fixed to the hub motor, and a steering angle module for driving the steering knuckle to rotate around a Z axis, and further comprising: An upper trailing arm assembly, the upper trailing arm assembly extending along the X-direction, one end of which is hingedly connected to the steering angle module and rotatable about the Y-axis, and the other end of which is connected to the vehicle frame and rotatable about the Y-axis; The lower longitudinal arm assembly is located below the upper longitudinal arm assembly and extends along the X direction. One end of the lower longitudinal arm assembly is universally rotatably hinged to the steering knuckle, and the other end is rotatably connected to the frame around the Y axis.

[0008] According to a longitudinal arm suspension structure with a hub motor provided in the present application, the upper longitudinal arm assembly and the lower longitudinal arm assembly are spaced apart along the Z direction, forming a four-link swing structure on the XZ plane.

[0009] According to a longitudinal arm suspension structure with a hub motor provided in the present application, the upper longitudinal arm assembly and the lower longitudinal arm assembly are of equal length in the X direction, and the projections of the upper longitudinal arm assembly and the lower longitudinal arm assembly on the XZ plane are parallelogram structures.

[0010] According to a trailing arm suspension structure with a hub motor provided by the present application, the upper trailing arm assembly includes: An upper trailing arm body, one end of which is hingedly connected to the steering angle module and the other end of which extends along the X direction; Multiple upper longitudinal arm support arms, one end of the upper longitudinal arm support arm is connected to the end of the upper longitudinal arm body away from the steering angle module, and the other end is hingedly connected to the upper fixed seat fixed on the frame through the upper rotating shaft in the Y direction. The connection ends of the multiple upper longitudinal arm support arms and the upper fixed seat are distributed at intervals along the Y direction.

[0011] According to a trailing arm suspension structure with a hub motor provided by the present application, the lower trailing arm assembly includes: A lower longitudinal arm body, one end of which is hingedly connected to the steering knuckle and the other end of which extends along the X direction; Multiple lower longitudinal arm support arms, one end of the lower longitudinal arm support arm is connected to the end of the lower longitudinal arm body away from the steering knuckle, and the other end is hingedly connected to the lower fixed seat fixed on the frame through the lower rotating shaft in the Y direction, and the multiple lower longitudinal arm support arms and the lower fixed seat connection ends are distributed at intervals along the Y direction.

[0012] According to a longitudinal arm suspension structure with a hub motor provided in the present application, it also includes a gas spring; the upper end of the gas spring is connected to the upper bracket of the shock absorber fixed on the vehicle frame, and the lower end is hingedly connected to the lower longitudinal arm assembly through the shock absorber pin shaft on the middle side of the lower longitudinal arm assembly so that it can rotate around the Y-axis.

[0013] According to a trailing arm suspension structure with a hub motor provided by the present application, the steering knuckle includes: A rotating shaft support, wherein the upper end of the rotating shaft support is provided with an upper tapered hole for transmission connection with the output shaft of the steering angle module; A trunnion seat is fixed to the lower end of the rotating shaft support by a bolt structure. A bowl seat with one side open for accommodating the ball pin at the end of the lower longitudinal arm assembly is formed between the trunnion seat and the lower end of the rotating shaft support. A lower tapered hole connected to the ball pin is opened on the trunnion seat; The lower tapered hole is coaxial with the upper tapered hole.

[0014] According to a trailing arm suspension structure with a hub motor provided in the present application, a steering gear support is installed at the upper end of the rotating shaft support; a retractable safety pin and a motor for controlling the retraction of the safety pin are provided in the steering gear support; when a fault occurs, the safety pin is driven by the motor to be inserted into the steering angle module to lock the steering angle module and the steering knuckle.

[0015] According to a trailing arm suspension structure with a hub motor provided in the present application, a sleeve corresponding to the side pin of the steering knuckle is provided at the end of the upper trailing arm assembly; a bushing with an interference fit is pressed into the sleeve; an oil guide groove is provided on the inner side of the bushing; and a fuel nipple connected to the oil guide groove is provided on the sleeve.

[0016] According to a longitudinal arm suspension structure with a hub motor provided in the present application, it also includes a limit plate fixed on the vehicle frame; when the lower longitudinal arm assembly jumps to the maximum jump amount, the limit plate contacts the lower longitudinal arm assembly and limits the lower longitudinal arm assembly from further jumping.

[0017] According to a trailing arm suspension structure with a hub motor provided in the present application, a bolt hole is provided at one end of the lower trailing arm assembly close to the hub motor; a steering limit bolt for limiting the steering angle is installed in the bolt hole.

[0018] The advantages of the present application are as follows: 1. The trailing arm suspension structure of the present application adopts a double trailing arm structure, with the upper trailing arm assembly connected to the steering angle module and the lower trailing arm assembly connected to the steering knuckle. This solves the problem that the wheel hub motor is large in size and, after being assembled with the tire assembly, occupies a lot of space in the X direction of the vehicle, resulting in difficulty in arranging the suspension in the X direction. The double trailing arm structure of the present application also solves the problems that the length of the transverse arm is limited, which affects the K&C characteristics of the suspension and thus limits the improvement of vehicle handling stability and smoothness, and is not convenient for installing hydro-pneumatic springs or air springs. The double trailing arm structure can flexibly design the arm length according to needs, ensuring the up and down bounce travel and smoothness requirements of the suspension. At the same time, hydro-pneumatic springs or air springs can be installed to adjust the movement travel of the tire. At the same time, the connection structure of the double trailing arm with the steering angle module and the steering knuckle meets the requirements of large wheel rotation, realizing the vehicle's crab walk, large turning angle, on-the-spot turning, sideways driving, and even forward and backward switching, meeting the driving and parking requirements of future vehicles in various complex road conditions. It is particularly suitable for some urban transportation vehicles and special vehicles such as unmanned vehicles, obstacle vehicles, and transport vehicles. 2. The upper and lower trailing arm assemblies of the present application are spaced apart and distributed on the upper and lower sides of the wheel hub motor, forming a four-link swing structure, which ensures the suspension's up and down bounce travel and smoothness requirements; the upper and lower trailing arm assemblies are respectively arranged in the upper and lower directions of the tire wheel center and have an arc-shaped structure, which avoids interference when the tire rotates in the opposite direction, increases the tire's reverse rotation angle, and ensures the vehicle's normal angular steering function; at the same time, the double trailing arm structure has a more uniform force distribution and is more reliable than the single trailing arm structure; 3. The upper and lower trailing arm assemblies of the present application form a parallelogram structure in the XZ plane, and the caster angle remains essentially unchanged when the suspension moves up and down. The vehicle's camber angle can be independently adjusted by adjusting the thickness and number of shims added between the upper and lower trailing arm assemblies and the frame rails, and the vehicle's wheelbase can be slightly adjusted. By calibrating the steering angle module, the vehicle's toe can be easily adjusted, preventing the four-wheel parameters from deviating from the design values ​​due to manufacturing precision and assembly errors, and facilitating vehicle performance tuning. 4. The upper and lower trailing arm assemblies of the present application have a Y-shaped structure, with a single-point connection between the steering angle module and the steering knuckle and a double-point connection between the module and the vehicle frame. This allows for uniform force distribution and high material utilization, effectively transmitting the longitudinal and lateral forces acting on the vehicle while reducing structural weight and production costs. 5. By adding a hydro-pneumatic spring structure, this application can efficiently transmit the vibration force of the frame, play a good role in buffering and reducing vibration. The vibration reduction effect of the entire suspension is greatly improved. The hydro-pneumatic spring can also be used to adjust the movement stroke of the tire; 6. The steering knuckle assembly of the present application adopts a split design. The trunnion seat can be assembled separately from the ball pin of the lower trailing arm assembly and then fixed to the shaft support by bolts. This can solve the problem of limited space for the ball pin arrangement inside the rim and reduce the kingpin offset. 7. This application can achieve mechanical safety protection for the steering angle module by setting a safety pin. When the steering angle module fails, the fault can be downgraded to lock the angular steering function of the wheel to ensure that the wheel is in the correct position, and switch to the hub motor differential steering mode to realize the steering function, thereby ensuring the normal driving of the vehicle and the safety of personnel; 8. The sleeve structure is provided at the end of the upper trailing arm assembly of the present application, which can be conveniently connected to the steering angle module. The grease nipple is provided to facilitate the filling of grease to lubricate the bushing, preventing rust damage and abnormal noise. 9. This application sets a limit plate on the vehicle frame to limit the upward jump of the lower trailing arm assembly, avoiding safety problems caused by excessive upward jump; 10. The present application is also provided with a steering limit bolt, by adjusting the steering limit bolt, the steering limit can be adjusted. The adjustment method is simple and the operation is convenient.

[0019] The trailing arm suspension structure of the present application is simple and can meet the future needs of vehicles for driving and parking on various complex road conditions. The double trailing arm structure occupies little space in the X direction and is easy to arrange, thereby improving the stability and smoothness of the suspension structure and having great promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 : Schematic diagram of the trailing arm suspension structure with a hub motor of the present application; Figure 2 : Schematic diagram of the upper longitudinal arm assembly structure of the present application; Figure 3 : Schematic diagram of the lower longitudinal arm assembly structure of the present application; Figure 4 : Schematic diagram of the steering knuckle structure of this application; Among them: 1—wheel assembly; 2—wheel hub motor; 3—steering knuckle; 31—rotating shaft support; 32—ear axle seat; 33—steering gear support; 34—safety pin; 4—upper longitudinal arm assembly; 41—upper longitudinal arm body; 42—upper longitudinal arm support arm; 43—sleeve; 44—bushing; 45—fuel injector; 5—lower longitudinal arm assembly; 51—lower longitudinal arm body; 52—lower longitudinal arm support arm; 53—ball pin; 6—steering angle module; 7—upper fixing seat; 8—lower fixing seat; 9—oil and gas spring; 10—shock absorber upper bracket; 11—shock absorber pin; 12—limit plate; 13—steering limit bolt. DETAILED DESCRIPTION

[0021] The embodiments of the present application are described in detail below, wherein the same or similar reference numerals throughout represent the same or similar elements or elements having the same or similar functions. The embodiments described below with reference to the accompanying drawings are exemplary and are intended to be used to explain the present application, and should not be construed as limiting the present application.

[0022] In the description of this application, it should be understood that the terms "longitudinal", "transverse", "length", "width", "thickness", "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating the orientation or position relationship, are based on the orientation or position relationship shown in the accompanying drawings, and are only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on this application.

[0023] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of the technical features indicated. Thus, a feature specified as "first" or "second" may explicitly or implicitly include one or more of the features. Throughout the description of this application, "plurality" means at least two, such as two, three, etc., unless otherwise specifically defined.

[0024] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0025] The present application relates to a longitudinal arm suspension structure with a hub motor. The wheel assembly used in the suspension structure of the present application is equipped with a hub motor. The hub motor of the present application adopts a distributed drive form and can realize differential steering of the vehicle when necessary. The hub motor assembly has its own braking system. The vehicle realizes the start-stop function and power supply of the vehicle through the hub motor. The suspension structure of the present application adopts a double longitudinal arm structure. The double longitudinal arms are placed on the upper and lower sides of the hub motor wheel center, which effectively avoids interference when the tire rotates in the opposite direction, increases the angle of reverse rotation of the tire, and ensures the normal angular steering function of the vehicle. At the same time, the structural form of the double longitudinal arm is more reliable than the single longitudinal arm structure because of uniform force. In addition, the double longitudinal arm structure of the present application has a simple X-direction front end structure and occupies very little space. It can be completely arranged within the motion envelope of the rim, ensuring that the tire can complete a rotation of more than 90 degrees to realize the lateral movement of the vehicle. At the same time, the double trailing arm structure adopted in this application connects the steering knuckle and the steering angle module respectively. The steering angle module can directly drive the wheels to rotate, which can solve various problems caused by differential steering, and at the same time meet the large-angle rotation of the wheels, realizing the vehicle's crab walk, large turning angle, on-the-spot turning, sideways travel and even front and rear switching, meeting the future vehicle's driving, parking and other use needs in various complex road conditions, and is particularly suitable for some urban transportation vehicles and special vehicles, such as unmanned vehicles, obstacle-crossing vehicles, transport vehicles, etc.

[0026] Specifically, such as Figures 1 to 4 A trailing arm suspension structure with a hub motor includes a wheel assembly 1, a hub motor 2 fixed on the wheel assembly 1, a steering knuckle 3 fixed to the hub motor 2, and a steering angle module 6 for driving the steering knuckle 3 to rotate around the Z axis. The hub motor 2 is a structure installed inside the wheel assembly 1. The hub motor 2 has its own braking function. The vehicle realizes the start and stop function and power supply of the vehicle through the hub motor. At the same time, the vehicle of the present application adopts a distributed drive structure. A group of hub motors 2 are provided on each wheel assembly 1, so the vehicle can realize differential steering of the vehicle through different hub motors 2.

[0027] The steering angle module 6 is connected to the steering knuckle 3 and can drive the steering knuckle 3 to rotate around the Z axis. In fact, the steering angle module 6 can drive the entire wheel assembly 1 to rotate. The steering angle module 6 and the wheel assembly 1 are arranged one-to-one. That is to say, the vehicle of the present application can drive the rotation of each wheel assembly 1 through the steering angle module 6 corresponding to the wheel assembly 1, thereby realizing the independent rotation of a single wheel assembly 1, realizing the vehicle's crab walk, large turning angle, on-the-spot turning, sideways travel and even front and rear switching, meeting the future vehicle's driving, parking and other usage needs in various complex road conditions.

[0028] The present application discloses a longitudinal arm suspension structure with a hub motor, which also includes an upper longitudinal arm assembly 4 and a lower longitudinal arm assembly 5. The upper longitudinal arm assembly 4 is arranged to extend along the X direction, and one end is hingedly connected to the steering angle module 6 and can rotate around the Y axis, and the other end is connected to the frame and can rotate around the Y axis. That is to say, during the suspension bounce process, both ends of the upper longitudinal arm assembly 4 are rotating connection structures around the Y axis, and the two ends of the upper longitudinal arm assembly 4 can achieve bounce adaptation between the wheel assembly 1 and the frame through this rotating hinge method.

[0029] The lower trailing arm assembly 5 is located below the upper trailing arm assembly 4 and extends along the X-axis. One end of the lower trailing arm assembly 5 is universally hinged to the steering knuckle 3, and the other end is connected to the vehicle frame for rotation about a Y-axis. The lower trailing arm assembly 5 is universally connected to the steering knuckle 3, meaning it does not affect the free rotation of the steering knuckle 3. The lower trailing arm assembly 5 serves to transfer load and vibration.

[0030] In some embodiments of the present application, the present embodiment optimizes the arrangement structure of the upper trailing arm assembly 4 and the lower trailing arm assembly 5. Specifically, Figure 1 As shown, the upper and lower trailing arm assemblies 4 and 5 of this embodiment are spaced apart along the Z direction, forming a four-bar linkage swing structure in the XZ plane. This four-bar linkage swing structure ensures the suspension's vertical travel and smoothness requirements. The upper and lower trailing arm assemblies 4 and 5 are respectively arranged on the upper and lower sides of the wheel center. The main parts of the upper and lower trailing arm assemblies 4 and 5 are arc-shaped structures, which avoid interference during reverse tire rotation, increase the reverse tire rotation angle, and ensure normal vehicle cornering function. At the same time, the double trailing arm structure formed by the upper and lower trailing arm assemblies 4 and 5 provides uniform force distribution and is more reliable than a single trailing arm structure.

[0031] Furthermore, the upper and lower trailing arm assemblies 4 and 5 are of equal length in the X-direction, and their projections on the XZ plane form a parallelogram structure. This parallelogram structure, formed by the upper and lower trailing arm assemblies 4 and 5, maintains a nearly constant caster angle (i.e., the connection between the upper and lower trailing arm assemblies 4 and 5 and the vehicle frame) when the suspension bounces up and down, further enhancing the stability of the suspension structure.

[0032] This embodiment employs spacers between the upper and lower trailing arm assemblies 4 and 5 and the frame rails. Adjusting the thickness and number of spacers allows for autonomous adjustment of the vehicle's camber angle and slight adjustments to the vehicle's track width. In practical applications, calibration of the steering angle module 6 facilitates convenient adjustment of the vehicle's toe, preventing deviations from the design values ​​of the four wheel parameters due to manufacturing precision and assembly errors, and facilitating overall vehicle performance tuning.

[0033] In a further embodiment of the present application, the present embodiment optimizes the above-mentioned upper longitudinal arm assembly structure 4 and the lower longitudinal arm assembly structure 5. Specifically, Figure 1 and 2 As shown, the upper longitudinal arm assembly 4 includes an upper longitudinal arm body 41 and multiple upper longitudinal arm support arms 42. One end of the upper longitudinal arm body 41 is hingedly connected to the steering angle module 6, and the other end extends along the X direction; one end of the upper longitudinal arm support arm 42 is connected to the end of the upper longitudinal arm body 41 away from the steering angle module 6, and the other end is hingedly connected to the upper fixing seat 7 fixed on the frame through the upper rotating shaft in the Y direction. The connection ends of the multiple upper longitudinal arm support arms 42 and the upper fixing seat 7 are spaced apart along the Y direction.

[0034] The connection between the upper trailing arm body 41 and the steering angle module 6 is very compact, taking up minimal space and encroaching only a small amount of space in the X-direction of the wheel hub, making it easy to arrange without affecting the rotation of the wheel assembly 1. In this embodiment, two upper trailing arm support arms 42 are connected to the ends of the upper trailing arm body 41. These two upper trailing arm support arms 42 and the upper trailing arm body 41 form a Y-shaped structure, providing excellent overall structural stability.

[0035] For the connection structure between the upper trailing arm assembly 4 and the steering angle module 6, as shown in FIG. Figure 2 As shown, a sleeve 43 corresponding to the side pin of the steering knuckle 3 is provided at the end of the upper longitudinal arm body 41, and a pin arranged along the Y direction is provided on the Y-direction side of the steering knuckle 3 away from the hub motor 2. When it is necessary to connect the upper longitudinal arm assembly 4 and the steering angle module 6, the pin is inserted into the sleeve at the end of the upper longitudinal arm body 41 to realize an articulated connection structure between the upper longitudinal arm body 41 and the steering angle module 6 that rotates around the Y-direction axis.

[0036] The connection between the sleeve 43 and the pin in this embodiment is provided with lubricating grease. Figure 2 As shown, a bushing 44 with an interference fit is press-fitted into sleeve 43. An oil guide groove is defined within bushing 44, and a grease nipple 45 is provided on sleeve 43, communicating with the oil guide groove. Gaskets and covers are positioned at both axial ends of sleeve 43. After the pin is inserted into sleeve 43, these gaskets and covers form a seal, facilitating the flow of grease from grease nipple 45 into the enclosed space.

[0037] Pairs of threaded holes are processed on the upper trailing arm body 41 , and the cable bracket of the hub motor 2 is fixed by bolts, which facilitates the cable arrangement of the hub motor 2 .

[0038] Regarding the connection structure between the upper trailing arm support arm 42 and the upper fixed seat 7, the upper fixed seat 7 is fixed to the vehicle frame. A trailing arm support is provided on the upper fixed seat 7, and a trailing arm bracket is mounted on the trailing arm support. The upper trailing arm support arm 42 is rotatably hinged to the trailing arm bracket via a Y-axis. The trailing arm brackets are located on either side of the upper trailing arm support arm 42 in the Y direction to restrict the Y-axis movement of the end of the upper trailing arm support arm 42, thereby stably connecting the upper trailing arm assembly 4 to the vehicle frame. Furthermore, because the upper trailing arm support arm 42 and the upper fixed seat 7 are hingedly connected about the Y-axis, and the upper trailing arm body 41 and the steering angle module 6 are also hingedly connected about the Y-axis, when the suspension bounces, the relative displacement between the vehicle frame and the wheel assembly 1 in the Z direction is not interfered with by the upper trailing arm assembly 4, and the entire suspension structure has a large vertical bounce travel.

[0039] The lower longitudinal arm assembly 5 of this embodiment includes a lower longitudinal arm body 51 and multiple lower longitudinal arm support arms 52. One end of the lower longitudinal arm body 51 is hingedly connected to the steering knuckle 3, and the other end extends along the X direction; one end of the lower longitudinal arm support arm 52 is connected to the end of the lower longitudinal arm body 51 away from the steering knuckle 3, and the other end is hingedly connected to the lower fixing seat 8 fixed on the frame through a lower rotating shaft in the Y direction. The connection ends of the multiple lower longitudinal arm support arms 52 and the lower fixing seat 8 are spaced apart along the Y direction.

[0040] In this embodiment, two lower longitudinal arm support arms 52 are disposed at the rear end of the lower longitudinal arm body 51. The two lower longitudinal arm support arms 52 form a Y-shaped structure with the lower longitudinal arm body 51. The lower longitudinal arm body 51 is an arc-shaped structure arranged along the X direction. This arc-shaped structure provides sufficient space for the rotation of the tire, so that the rotation of the tire is not restricted by the lower longitudinal arm body 51.

[0041] The connection structure between the lower longitudinal arm support arm 52 and the lower fixing seat 8 is the same as the connection structure between the upper longitudinal arm support arm 42 and the upper fixing seat 7, and will not be repeated again.

[0042] The connection structure between the lower longitudinal arm body 51 and the steering knuckle 3 is shown in FIG. Figure 1 and 3 As shown, a ball pin 53 is provided at the front end of the lower longitudinal arm body 51, and a ball bowl seat corresponding to the ball pin 53 is provided at the lower end of the steering knuckle 3. The ball pin 53 is universally rotatably connected to the ball bowl seat.

[0043] Because the lower longitudinal arm support arm 52 and the lower fixed seat 8 are rotatable hinged structures around the Y-axis, and the ball pin 53 and the steering knuckle 3 are universal rotation connection structures, the vertical jumping between the frame and the steering knuckle 3 at both ends of the lower longitudinal arm assembly 5 will not be interfered by the lower longitudinal arm assembly 5. At the same time, the universal rotation connection structure between the ball pin 53 and the steering knuckle 3 will not affect the rotation of the steering knuckle 3 around the Z-axis.

[0044] In other embodiments, this embodiment optimizes the structure of the steering knuckle 3, specifically, Figure 1 、 3 As shown in FIG4 , the steering knuckle 3 is bolted to the in-wheel motor 2. The steering knuckle 3 includes a shaft support 31 and a trunnion support 32. The upper end of the shaft support 31 is provided with an upper tapered hole that is transmission-connected to the output shaft of the steering angle module 6. A spline groove is provided in the upper tapered hole, corresponding to the spline provided on the output shaft of the steering angle module 6. When the output shaft of the steering angle module 6 is inserted into the upper tapered hole, the spline enters the corresponding spline groove, connecting the output shaft of the steering angle module 6 to the shaft support 31 of the steering knuckle 3. The steering angle module 6 can then drive the shaft support 31 to rotate about the Z axis, thereby rotating the wheel assembly 1.

[0045] like Figure 4 As shown, the trunnion seat 32 of this embodiment is fixed to the lower end of the rotating shaft support 31 via a bolt structure. A bowl seat with one side open between the trunnion seat 32 and the lower end of the rotating shaft support 31 is formed to accommodate the ball pin at the end of the lower trailing arm assembly 5. The trunnion seat 32 is provided with a lower tapered hole connected to the ball pin. The lower tapered hole is coaxial with the upper tapered hole, and the coaxial axis of the lower tapered hole and the upper tapered hole forms a virtual kingpin of the suspension. During assembly, the trunnion seat 32 can be first assembled with the ball pin 53 of the lower trailing arm assembly 5 and then fixed to the rotating shaft support 31 via a bolt and nut structure. This solves the problem of limited space for the ball pin inside the wheel rim and reduces the kingpin offset.

[0046] In a preferred embodiment of the present application, the connection structure between the above-mentioned rotating shaft support 31 and the steering angle module 6 is optimized. Figure 4 As shown, a steering gear support 33 is installed at the upper end of the shaft support 31. A retractable safety pin 34 and a motor for controlling the retraction of the safety pin 34 are provided in the steering gear support 33. When a fault occurs, the safety pin 34 is driven by the motor to be inserted into the steering angle module 6 to lock the steering angle module 6 and the steering knuckle 3.

[0047] The safety pin 34 is a safety control mechanism. Under normal driving conditions, the safety pin 34 extends a small amount and there is a small gap between it and the steering angle module 6. When the internal sensor of the steering angle module 6 identifies a fault, it sends a signal to control the motor to automatically adjust the extension of the safety pin 34, penetrate into the interior of the steering angle module 6, lock the angular steering function of the steering angle module 6, ensure that the wheel is in the correct position, and send a signal to the steering controller and the vehicle controller to adjust the wheel steering mode to use the hub motor differential steering to realize the steering function, thereby ensuring the normal driving of the vehicle and the safety of people.

[0048] In other embodiments of the present application, the structure of the lower longitudinal arm assembly 5 is further optimized. Specifically, Figure 1 and 3As shown, this embodiment also includes a gas spring 9, the upper end of which is connected to a shock absorber upper bracket 10 fixed to the vehicle frame, and the lower end is hingedly connected to the lower longitudinal arm assembly 5 through a shock absorber pin 11 on the middle side of the lower longitudinal arm assembly 5 so as to be rotatable around the Y-axis.

[0049] The vibration transmission path of this embodiment is: the force of the vehicle body is transmitted to the ground in sequence through the gas spring 9, the lower longitudinal arm assembly 5, the steering angle module 6, the hub motor 2, and the tire assembly 1. The gas spring 9 can attenuate the vibration transmitted to the entire vehicle by the wheel assembly 1, thereby improving the vibration damping effect of the entire suspension.

[0050] Furthermore, this embodiment includes a limit plate 12 fixed to the vehicle frame. When the lower trailing arm assembly 5 reaches its maximum upward jump, the limit plate 12 contacts the lower trailing arm assembly 5 and limits further upward jump. A limit surface is machined on the upper surface of the lower trailing arm 51, and contact and compression with the limit plate 12 limit the maximum upward jump of the suspension.

[0051] In addition, a bolt hole is provided at one end of the lower longitudinal arm assembly 5 near the wheel hub motor 2, in which a steering limit bolt 13 for limiting the steering angle is installed. The steering angle can be mechanically limited by adjusting the length of the assembled steering limit bolt 13.

[0052] The vehicle frame of the present application is not shown, wherein the shock absorber upper bracket 10, the limiting plate 12, the upper fixing seat 7 and the lower fixing seat 7 are fixed structures fixed on the vehicle frame or the vehicle body. More specifically, the upper fixing seat 7 and the lower fixing seat 7 are fixed to the longitudinal beam of the vehicle frame by four bolts.

[0053] The X direction in this application refers to the front and rear direction of the car, the Y direction in this application refers to the left and right direction of the car, and the Z direction in this application refers to the up and down direction of the car.

[0054] The above shows and describes the basic principles, main features, and advantages of the present application. Those skilled in the art should understand that the present application is not limited to the above embodiments. The above embodiments and descriptions are merely illustrative of the principles of the present application. Various changes and improvements may be made to the present application without departing from the spirit and scope of the present application. Such changes and improvements are intended to fall within the scope of the present application. The scope of protection claimed in this application is defined by the appended claims and their equivalents.

Claims

1. A trailing arm suspension structure with a hub motor, comprising a wheel assembly (1), a hub motor (2) fixed to the wheel assembly (1), a steering knuckle (3) fixed to the hub motor (2), and a steering angle module (6) for driving the steering knuckle (3) to rotate around a Z-axis, characterized in that: Also includes, An upper longitudinal arm assembly (4), the upper longitudinal arm assembly (4) extending along the X direction, one end of which is hingedly connected to the steering angle module (6) and rotatable about the Y axis, and the other end of which is connected to the vehicle frame and rotatable about the Y axis; A lower longitudinal arm assembly (5), wherein the lower longitudinal arm assembly (5) is located below the upper longitudinal arm assembly (4), and the lower longitudinal arm assembly (5) is arranged to extend along the X direction, and one end of the lower longitudinal arm assembly (5) is universally rotatably hinged to the steering knuckle (3), and the other end is rotatably connected to the vehicle frame about the Y axis.

2. A trailing arm suspension structure with a hub motor according to claim 1, characterized in that: The upper longitudinal arm assembly (4) and the lower longitudinal arm assembly (5) are spaced apart along the Z direction, forming a four-link swing structure on the XZ plane.

3. A trailing arm suspension structure with a hub motor according to claim 1 or 2, characterized in that: The upper longitudinal arm assembly (4) and the lower longitudinal arm assembly (5) are of equal length in the X direction, and the projections of the upper longitudinal arm assembly (4) and the lower longitudinal arm assembly (5) on the XZ plane are parallelogram structures.

4. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: The upper trailing arm assembly (4) includes: An upper longitudinal arm body (41), one end of the upper longitudinal arm body (41) is hingedly connected to the steering angle module (6), and the other end extends along the X direction; A plurality of upper longitudinal arm support arms (42), one end of the upper longitudinal arm support arm (42) being connected to an end of the upper longitudinal arm body (41) away from the steering angle module (6), and the other end being hingedly connected to an upper fixing seat (7) fixed on the vehicle frame via an upper rotating shaft in the Y direction, and the connection ends of the plurality of upper longitudinal arm support arms (42) and the upper fixing seat (7) being spaced apart along the Y direction.

5. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: The vehicle also includes an oil-gas spring (9); the upper end of the oil-gas spring (9) is connected to a shock absorber upper bracket (10) fixed to the vehicle frame, and the lower end is hingedly connected to the lower longitudinal arm assembly (5) through a shock absorber pin (11) on the middle side of the lower longitudinal arm assembly (5) so as to be rotatable around the Y axis.

6. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: The steering knuckle (3) comprises: A rotating shaft support (31), wherein the upper end of the rotating shaft support (31) is provided with an upper tapered hole for transmission connection with the output shaft of the steering angle module (6); A trunnion seat (32) is fixed to the lower end of the rotating shaft support (31) by a bolt structure, and a ball bowl seat with an opening on one side for accommodating the ball pin at the end of the lower longitudinal arm assembly (5) is formed between the trunnion seat (32) and the lower end of the rotating shaft support (31), and a lower tapered hole connected to the ball pin is opened on the trunnion seat (32); The lower tapered hole is coaxial with the upper tapered hole.

7. The trailing arm suspension structure with a hub motor according to claim 6, characterized in that: A steering gear support (33) is mounted on the upper end of the rotating shaft support (31); a retractable safety pin (34) and a motor for controlling the retraction of the safety pin (34) are arranged in the steering gear support (33); when a fault occurs, the safety pin (34) is driven by the motor to be inserted into the steering angle module (6) to lock the steering angle module (6) and the steering knuckle (3).

8. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: The end of the upper longitudinal arm assembly (4) is provided with a sleeve (43) corresponding to the side pin of the steering knuckle (3); a bushing (44) with an interference fit is press-fitted inside the sleeve (43); an oil guide groove is provided inside the bushing (44); and a fueling nipple (45) in communication with the oil guide groove is provided on the sleeve (43).

9. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: It also includes a limit plate (12) fixed on the vehicle frame; when the lower longitudinal arm assembly (5) jumps up to the maximum jump amount, the limit plate (12) contacts the lower longitudinal arm assembly (5) and limits the lower longitudinal arm assembly (5) from further jumping up.

10. The trailing arm suspension structure with a hub motor according to claim 1, characterized in that: A bolt hole is provided at one end of the lower longitudinal arm assembly (5) close to the wheel hub motor (2); a steering limit bolt (13) for limiting the steering angle is installed in the bolt hole.

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