Low-bed electric light truck and wheel-side driving device

Abstract

The application discloses a low-cargo-platform electric light truck and a wheel-side driving device, and relates to the field of electric light trucks, and in particular to a low-cargo-platform electric light truck and a wheel-side driving device. The low-cargo-platform electric light truck comprises a cab, a front axle assembly, a cargo box, a low-cargo-platform frame and a rear axle assembly. The low-cargo-platform frame is of a stepped sectional structure, and the middle section of the frame longitudinal beam is offset downward relative to the front section. The rear axle assembly is of a double-rear-wheel distributed wheel-side driving structure, and a driving motor directly drives a tire through a planetary gear reducer. The cargo box is fixed on the middle and rear sections of the frame and the cross beam through bottom supports. Through the adaptive design of the low-cargo-platform frame and the wheel-side driving, the application realizes the reduction of the cargo platform height, the increase of the loading capacity, and the advantages of high transmission efficiency, compact structure and convenient loading and unloading, and is suitable for urban distribution logistics scenes.

Description

Technical Field

[0001] This invention relates to the field of new energy commercial vehicle technology, and in particular to a low-platform electric light truck and its wheel-side drive device. Background Technology

[0002] Currently, electric light trucks are widely used in urban distribution and logistics scenarios. Their drive system and cargo platform height directly affect the overall vehicle efficiency, load-bearing capacity, and economic efficiency.

[0003] Existing electric light truck drive systems mainly adopt an integrated electric drive axle or a layout consisting of a central motor, drive shaft, and rear axle. Distributed wheel-side drive, due to its advantages such as short drive chain, high transmission efficiency, compact structure, and independent controllable wheel torque, is gradually becoming an important research and development direction for electric light trucks. However, existing wheel-side drive solutions are mostly used in heavy-duty trucks and have problems such as complex structure, high weight and cost, and inability to independently and precisely control the two rear wheels, making it difficult to directly adapt to the usage requirements of electric light trucks.

[0004] Regarding the cargo platform and chassis, traditional light trucks have relatively high cargo platforms, resulting in drawbacks such as inconvenient loading and unloading, limited loading capacity, and poor adaptability to various scenarios. While existing low-cargo-platform electric light trucks have reduced the height of the cargo box floor through a stepped chassis, they still suffer from shortcomings such as redundant arched chassis avoidance structures, the need for additional mounting beams or supports for cargo box installation, relatively high overall vehicle weight, and high assembly and manufacturing costs. Consequently, they cannot simultaneously achieve a comprehensive optimization of low cargo platform, large volume, lightweight design, and high loading and unloading efficiency while meeting the requirements of blue-plate compliant load limits.

[0005] Therefore, how to integrate distributed wheel-side drive with low-platform vehicle frame in a compatible design to simplify the structure, reduce weight, and improve transmission efficiency and loading capacity has become a technical problem that urgently needs to be solved in this field. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to provide a low-platform electric light truck and wheel-side drive device with simplified structure, high transmission efficiency, lightweight frame, low platform, large loading capacity and convenient installation. It overcomes the shortcomings of existing distributed wheel-side drive structures which are complex and difficult to adapt to electric light trucks, as well as the redundancy of existing low-platform frames, cumbersome cargo box installation and inability to balance platform height and loading capacity.

[0007] The technical problem to be solved by the present invention is achieved through the following technical solution:

[0008] A low-platform electric light truck includes a cab, a front axle assembly, a cargo box, a low-platform frame, and a rear axle assembly;

[0009] The low-platform chassis has a stepped segmented structure, including a front section of the chassis longitudinal beam, a middle section of the chassis longitudinal beam, and a dovetail beam of the rear section of the chassis longitudinal beam arranged sequentially along the longitudinal direction of the vehicle; the middle section of the chassis longitudinal beam is offset downward relative to the front section of the chassis longitudinal beam.

[0010] The rear axle assembly is a dual rear wheel distributed wheel-side drive structure, including a rigid axle body, two sets of drive motors, two sets of planetary gear reducers, two sets of brakes, and two tires. The output end of the drive motor is directly connected to the sun gear of the planetary gear reducer. The sun gear meshes externally with the planet gears, and the planet gears mesh internally with the internal gear ring. The internal gear ring is fixed to the reducer housing, and the reducer housing is fixedly connected to the rigid axle body. The planet gears drive the planet carrier to rotate, and the planet carrier is directly connected to the tires.

[0011] The bottom of the cargo box is provided with a cargo box longitudinal beam mounting bracket, which supports and fixes the middle section of the frame longitudinal beam, the dovetail beam of the rear section of the frame longitudinal beam, and the third to ninth crossbeams of the low cargo platform frame.

[0012] Preferably, in the above technical solution, the two sets of drive motors are controlled by independent motor controllers, and the independent distribution of the speed and torque of the two rear wheels is achieved through electronic differential algorithm; the planetary gear reducer is integrated on the wheel side, and the drive motor, planetary gear reducer, brake and tire are arranged in sequence along the wheel rotation axis.

[0013] Preferably, in the above technical solution, the rear section of the frame longitudinal beam dovetail beam has a variable cross-section structure that is wider at the front and narrower at the rear, and the rear section of the frame longitudinal beam dovetail beam is located in the rear suspension leaf spring mounting area; the height difference between the middle section of the frame longitudinal beam and the front section of the frame longitudinal beam is 350mm to 450mm.

[0014] Preferably, in the above technical solution, the battery pack is fixed below the fourth to sixth crossbeams of the low cargo platform frame, and the low-voltage battery is arranged on the outer front end of the right longitudinal beam of the low cargo platform frame.

[0015] Preferably, in the above technical solution, the EPB controller and MCU are arranged between the eighth tube beam and the ninth cross beam of the low cargo platform frame, and the high-voltage distribution box is arranged under the cab.

[0016] Preferably, in the above technical solution, the vehicle adopts a 540V voltage platform, the braking system is a hydraulic integrated driving and parking brake, the rated load of the rear axle assembly is 4T, and the height of the unloaded cargo platform is no more than 650mm.

[0017] Preferably, in the above technical solution, the middle section of the longitudinal beam of the frame and the front section of the longitudinal beam of the frame are connected by a connecting plate, the connecting plate is a steel-aluminum composite connecting plate, the rigid axle body is made of lost foam casting axle tube, and the wheel well gap is not less than 1200mm.

[0018] Preferably, in the above technical solution, the front axle assembly is a non-drive steering axle.

[0019] Preferably, in the above technical solution, the bottom plate of the cargo box is 400mm lower than the ground, and the cargo box volume is increased by 15%.

[0020] A wheel-side drive device includes a rigid axle, two drive motors, two planetary gear reducers, two brakes, and two tires. The drive motors are axial flux motors, fixedly connected to both sides of the rigid axle, with their output shafts directly connected to the sun gear of each planetary gear reducer. Each planetary gear reducer includes a sun gear, planet gears, an internal gear ring, and a planet carrier. The internal gear ring is fixed to the reducer housing, which is fixedly connected to the rigid axle. The planet carrier is directly connected to the tires. The two drive motors are independently powered and have independent torque control, achieving independent drive for both rear wheels via electronic differential.

[0021] The above-described technical solution of the present invention has the following beneficial effects:

[0022] (1) Adopting a dual rear wheel drive structure, eliminating intermediate transmission components such as traditional drive shafts and main reducers, the transmission efficiency is increased to over 95%, significantly reducing energy loss and increasing range. At the same time, the overall vehicle layout is optimized, reducing the performance requirements of a single motor. The dual motors independently and precisely control the different speeds and torques of the inner and outer wheels.

[0023] (2) The lightweight design of the wheel-side drive system and the lightweight structure of the low-platform chassis (dovetail beam + high-strength steel) work together to reduce the overall vehicle weight. At the same time, the platform is lowered by 400mm, which increases the cargo box volume by 15%. Under the total mass limit of blue-plate light trucks, it can carry 3m³ more per trip, thus optimizing load-bearing performance and compliance.

[0024] (3) Improve loading and unloading efficiency and broaden application scenarios, and significantly reduce operating and maintenance costs. The center of gravity of the whole vehicle is lowered and the load-bearing capacity of the dual rear wheels is optimized, enhancing driving safety and accurately matching the urban new energy logistics vehicle traffic policy. Attached Figure Description

[0025] The accompanying drawings, which are incorporated in and form part of this specification, illustrate embodiments of the invention and, together with their description, serve to explain the principles of the invention.

[0026] Figure 1 This is a schematic diagram of the electric light truck of the present invention;

[0027] Figure 2 This is a schematic diagram of the power layout of the electric light truck of the present invention;

[0028] Figure 3 This is a diagram of the dual-wheel drive device for the electric light truck of the present invention;

[0029] Figure 4 This is a schematic diagram of the dual-motor wheel-side drive assembly transmission of the electric light truck of the present invention;

[0030] Figure 5 This is a schematic diagram of the chassis platform of the electric light truck of the present invention;

[0031] Figure 6 This is a top view of the cargo box bottom of the electric light truck of the present invention;

[0032] Figure 7 This is a top view of the chassis platform of the electric light truck of the present invention.

[0033] The diagram shows the following: 1-Cabin; 2-Front axle assembly; 3-Cargo box; 4-Low cargo platform frame; 5-Rear axle assembly; 6-Drive assembly; 7-Battery pack; 10-Rigid axle body; 11-Drive motor; 12-Internal gear ring; 13-Sun gear; 14-Planet carrier; 15-Planet gear; 16-Tire; 18-Front section of frame longitudinal beam; 19-Middle section of frame longitudinal beam; 20-Dovetail beam of rear section of frame longitudinal beam; 21-Rear leaf spring hanger; 22-Leaf spring bracket; 23-Second leaf spring bracket; 24-First crossbeam; 25-Second crossbeam; 26-Third crossbeam; 27-Ninth crossbeam. Detailed Implementation

[0034] Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that, unless otherwise specifically stated, the relative arrangement, numerical expressions, and values ​​of the components and steps set forth in these embodiments do not limit the scope of the invention.

[0035] Unless otherwise specified, the experimental methods used in the following examples are conventional methods, and the materials and reagents used are commercially available. Unless otherwise specified, the equipment used in the experiments is well known to those skilled in the art.

[0036] like Figure 1 As shown, the low-platform electric light truck of this embodiment includes a cab 1, a front axle assembly 2, a cargo box 3, a low-platform frame 4, and a rear axle assembly 5.

[0037] The cab 1 is located at the front of the vehicle, with the radiator, condenser, high-voltage electrical distribution box, and air conditioning compressor arranged below it; the front axle assembly 2 is a non-drive steering axle used to realize the vehicle steering function; the low cargo platform frame 4 is the load-bearing base of the whole vehicle, and adopts a stepped segmented sinking structure; the cargo box 3 is installed on the middle and rear section of the low cargo platform frame 4; the rear axle assembly 5 is a dual rear wheel distributed wheel-side drive structure, replacing the traditional drive axle and drive shaft.

[0038] The chassis adopts a brand-new stepped segmented design, lowering the cargo platform by 400mm. This allows the electric light truck to increase the cargo box volume by 15%, carrying an additional 3m³ per trip, while avoiding the problems of front-wheel drive low-cargo-platform products being unable to handle heavy loads and slipping when climbing slopes. The rear axle assembly 5 has been changed to a wheel-side electric drive axle, integrating the axial flux drive motor 11, wheel-side planetary gear reducer, electronic differential, lost foam cast axle tube, and integrated travel and parking brake. The cargo box 3 and its protective structure have been redesigned. The low-voltage battery is located on the outer front end of the right longitudinal beam of the low-cargo-platform chassis 4, and the EPB controller and MCU are located between the eight-tube beam and the nine-cross beam. The overall unloaded cargo platform height is ≤650mm, and the rear axle assembly 5 has a rated load capacity of 4T, meeting the compliance load requirements of the new blue-plate regulations.

[0039] like Figure 2 As shown, the vehicle's powertrain system includes a drive assembly 6, a battery pack 7, a front axle assembly 2, and a rear axle assembly 5. The battery pack is fixed below the fourth to sixth crossbeams of the low cargo platform frame 4, resulting in a low center of gravity, compact layout, and optimized axle load distribution for the entire vehicle.

[0040] The drive assembly 6 consists of a rigid axle 10, dual rear-wheel drive motors 11, a planetary gear reducer, brakes, and tires 16. The vehicle's voltage platform is 540V. The drive motors 11 have a power output of 2×62 / 85kW, a torque of 2×200 / 480Nm, and a speed of 2960 / 5000r / min. The reducer has a speed ratio of 6.3, and the maximum torque output at the wheel ends is 6048N·m. Dual rear-wheel independent torque control, achieved through electronic differential for precise power distribution, results in a smaller turning radius and enhanced maneuverability. By eliminating redundant transmission components such as traditional driveshafts and main reducers, power is directly transmitted to the wheels, significantly increasing heavy-load climbing ability and achieving a transmission efficiency of over 95%.

[0041] like Figure 3 As shown, the dual-wheel-side drive device includes dual rear-wheel-side drives, tires 16, and a rigid axle 10. The rigid axle 10 is made of lost foam casting axle tube and serves as the load-bearing base for the wheel-side drives. Independent dual rear-wheel-side drives 1 are set on both sides. The drive motor 11, planetary gear reducer, brake, and tires 16 are arranged sequentially along the wheel rotation axis. The planetary gear reducer is integrated into the wheel side, resulting in a compact structure and small space occupation, providing a layout basis for low platform design.

[0042] like Figure 4 As shown, the transmission structure of the dual-motor wheel-side drive assembly includes a drive motor 11, an internal gear ring 12, a sun gear 13, a planet carrier 14, planet gears 15, and a tire 16.

[0043] The drive motor 11 is an axial flux motor. Two drive motors 11 output high-speed, low-torque power, directly connected to the sun gear 13 of the planetary gear mechanism, driving the sun gear 13 to rotate. The sun gear 13 externally meshes with the planet gears 15, driving the planet gears 15 to rotate. The axis of the planet gears 15 is mounted on the planet carrier 14 and simultaneously meshes with the internal gear ring 12. The internal gear ring 12 is fixed to the reducer housing, which is fixedly connected to the rigid bridge body 10. With the internal gear ring 12 fixed, the planet gears 15 revolve around the sun gear 13, driving the planet carrier 14 to rotate synchronously. Through the rotation and revolution of the planet gears 15, speed reduction and torque amplification are achieved (typically amplifying the torque several times), meeting the power transmission requirements of wheel-side drive. The planet carrier 14 is directly connected to the tire 16, and its rotational motion is ultimately transmitted to the tire 16, driving the wheel to rotate.

[0044] The two sets of drive motors 11 are controlled by independent motor controllers. Through electronic differential algorithm, the speed and torque of the two rear wheels are independently distributed, which effectively improves the driving safety and handling flexibility of the vehicle and meets the usage requirements of urban distribution transportation scenarios.

[0045] like Figure 5 As shown, the low cargo platform frame 4 has a stepped segmented structure, including the front section 18 of the frame longitudinal beam, the middle section 19 of the frame longitudinal beam, the dovetail beam 20 of the rear section of the frame longitudinal beam, and also includes the rear leaf spring hanger 21, leaf spring bracket 22, auxiliary leaf spring bracket 23, first crossbeam 24, and second crossbeam 25.

[0046] The low cargo platform frame 4 consists of two opposing longitudinal beams and multiple transverse beams. The longitudinal beams are arranged in sequence along the longitudinal direction of the vehicle as the front section 18, the middle section 19, and the rear section dovetail beam 20. The middle section 19 is offset downward relative to the front section 18, and the height difference between the two is 350mm to 450mm.

[0047] The middle section 19 of the frame longitudinal beam adopts a 200mm truncated and recessed structural design, and the outer width of the frame is 940mm. The front section 18 of the frame longitudinal beam and the middle section 19 of the frame longitudinal beam have an overlapping area in the vertical direction, and the overlapping area is fixed by bolts through a steel-aluminum connecting plate. The front section 18 of the frame longitudinal beam and the middle section 19 of the frame longitudinal beam are fixedly connected by a connecting plate, preferably a steel-aluminum composite connecting plate.

[0048] Compared to the middle section of the frame longitudinal beam 19, the rear section dovetail beam 20 adopts a variable cross-section dovetail beam design with a wider front and narrower rear, and is located in the rear suspension leaf spring mounting area, so there is no need to set up an additional arched avoidance structure; the whole has the comprehensive advantages of lightweight, lower vehicle center of gravity, reasonable structural layout, high overall strength and long fatigue life.

[0049] The frame's crossbeams include the first through ninth crossbeams.

[0050] like Figure 6 and Figure 7 As shown,

[0051] The crossbeams of the low cargo platform frame 4 include the first to the ninth crossbeams, of which the eighth crossbeam adopts a tubular beam structure.

[0052] This application, while lowering the middle section of the longitudinal beams of the chassis, features a dedicated design for the third to ninth crossbeams 26 to 27 of the chassis. The bottom of the cargo box 3 is equipped with a cargo box longitudinal beam mounting bracket, which supports and fixes the middle section 19 of the longitudinal beams of the chassis 4, the dovetail beam 20 of the rear section of the longitudinal beams, and the third to ninth crossbeams. This eliminates the need for additional cargo box mounting beams and welding supports to the chassis, greatly reducing the contact distance between the cargo box 3 and the chassis, reducing the design cost of the cargo box 3, and lowering the overall vehicle weight.

[0053] Meanwhile, the dual rear wheel drive structure greatly reduces the space occupied by the rear axle assembly 5, lowers the total height of the cargo platform by 400mm, increases the volume of the cargo box 3 by 15%, and improves the loading capacity of the electric light truck; the lower floor of the cargo box 3 is lowered from the ground, allowing entry and exit of the cargo box 3 without stepping, improving the convenience and efficiency of loading and unloading goods, and can be operated by a single person.

[0054] Vehicle system supplement:

[0055] In this application, the vehicle braking system adopts hydraulic braking, integrating driving and parking. The driving brake pipeline is designed according to the brake position, and the parking brake adopts EPB. It uses a low-voltage 24V power battery (arranged inside the longitudinal beam of the frame). The motor controller adopts a multi-in-one high-voltage box (including a single MCU) and a single motor controller solution, which has functions such as creep, anti-slip, anti-skid, and active anti-shake, improving the overall driving performance of the vehicle. The high-voltage box is located at the front of the cab 1, and the high-voltage box borrows the LBF28 state, with a 540V high-voltage platform. The rear axle assembly 5 adopts a load-bearing rear axle with a load capacity of 5t in the later stage, a wheel arch clearance ≥1200mm, reasonable front and rear axle load distribution, and excellent handling and braking performance.

[0056] Although the present invention has been disclosed above with reference to embodiments, it is not intended to limit the present invention. Any person skilled in the art can make various different choices and modifications without departing from the spirit and scope of the present invention. Therefore, the scope of protection of the present invention is defined by the claims and their equivalents.

Claims

1. A low-platform electric light truck, characterized in that, Includes cab (1), front axle assembly (2), cargo box (3), low cargo platform frame (4), and rear axle assembly (5); The low cargo platform frame (4) is a stepped segmented structure, including the front section (18), the middle section (19), and the rear section dovetail beam (20) of the frame longitudinal beam arranged sequentially along the longitudinal direction of the vehicle; the middle section (19) of the frame longitudinal beam is offset downward relative to the front section (18) of the frame longitudinal beam. The rear axle assembly (5) is a dual rear wheel distributed wheel-side drive structure, including a rigid axle body (10), two sets of drive motors (11), two sets of planetary gear reducers, two sets of brakes, and two tires (16). The output end of the drive motor (11) is directly connected to the sun gear (13) of the planetary gear reducer. The sun gear (13) meshes externally with the planet gears (15). The planet gears (15) mesh internally with the internal gear ring (12). The internal gear ring (12) is fixed to the reducer housing. The reducer housing is fixedly connected to the rigid axle body (10). The planet gears (15) drive the planet carrier (14) to rotate. The planet carrier (14) is directly connected to the tires (16). The bottom of the cargo box (3) is provided with a cargo box longitudinal beam mounting bracket, which supports and fixes the middle section (19) of the frame longitudinal beam, the rear section dovetail beam (20) of the frame longitudinal beam, and the third to ninth crossbeams (22) of the low cargo platform frame (4).

2. The electric light truck according to claim 1, characterized in that, The two sets of drive motors (11) are controlled by independent motor controllers, and the independent distribution of the speed and torque of the two rear wheels is achieved through electronic differential algorithm; the planetary gear reducer is integrated on the wheel side, and the drive motor (11), planetary gear reducer, brake (17) and tire (16) are arranged in sequence along the wheel rotation axis.

3. The electric light truck according to claim 1, characterized in that, The rear section of the frame longitudinal beam dovetail beam (20) has a variable cross-section structure that is wider at the front and narrower at the rear. The rear section of the frame longitudinal beam dovetail beam (20) is located in the rear suspension leaf spring mounting area. The height difference between the middle section (19) of the frame longitudinal beam and the front section (18) of the frame longitudinal beam is 350mm to 450mm.

4. The electric light truck according to claim 1, characterized in that, The battery pack (7) is fixed below the fourth to sixth crossbeams of the low cargo platform frame (4), and the low-voltage battery is arranged on the outer front end of the right longitudinal beam of the low cargo platform frame (4).

5. The electric light truck according to claim 1, characterized in that, The EPB controller and MCU are arranged between the eighth tube beam and the ninth cross beam of the low cargo platform frame (4), and the high voltage distribution box is arranged in the lower part of the cab (1).

6. The electric light truck according to claim 1, characterized in that, The vehicle adopts a 540V voltage platform, the braking system is a hydraulic parking brake, the rated load of the rear axle assembly (5) is 4T, and the height of the unloaded cargo platform is no more than 650mm.

7. The electric light truck according to claim 1, characterized in that, The middle section (19) of the frame longitudinal beam and the front section (18) of the frame longitudinal beam are connected by a connecting plate, which is a steel-aluminum composite connecting plate. The rigid bridge body (10) is made of lost foam casting bridge tube, and the wheel rim gap is not less than 1200mm.

8. The electric light truck according to claim 1, characterized in that, The front axle assembly (2) is a non-drive steering axle.

9. The electric light truck according to claim 1, characterized in that, The bottom plate of the cargo box (3) is 400mm lower than the ground, and the cargo box volume is increased by 15%.

10. A wheel-side drive device, characterized in that, The system includes a rigid bridge (10), two drive motors (11), two planetary gear reducers, two brakes, and two tires (16). The drive motors (11) are axial flux motors, and are fixedly connected to both sides of the rigid bridge (10). The output shaft of the drive motors (11) is directly connected to the sun gear (13) of the planetary gear reducer. The planetary gear reducer includes a sun gear (13), planet gears (15), an internal gear ring (12), and a planet carrier (14). The internal gear ring (12) is fixed to the reducer housing, and the reducer housing is fixedly connected to the rigid bridge (10). The planet carrier (14) is directly connected to the tires (16). The two drive motors (11) are independently powered and have independent torque control, and the dual rear wheels are driven independently through electronic differential.

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