Pure electric truck two-gear transmission
By using a planetary reduction assembly to connect the coupling assembly and the transmission assembly in the pure electric truck gearbox, a coaxial transmission structure is formed, which solves the problems of long transmission routes and low efficiency, achieves higher transmission stability and efficiency, outputs greater torque, and adapts to harsh working conditions.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- ZHUZHOU GEAR CO LTD
- Filing Date
- 2025-08-05
- Publication Date
- 2026-07-24
AI Technical Summary
Existing pure electric vehicle transmissions suffer from problems such as long transmission routes, low transmission efficiency, large size, difficult layout, high cost of multi-planetary gear structure, insufficient transmission stability and long-term reliability, and poor performance, especially under harsh working conditions.
The coupling component and the speed change component are coaxially connected through a planetary reduction component, and the speed change component and the output shaft are coaxially connected through a second planetary reduction component. This forms a coaxial transmission connection between the coupling component, the first planetary reduction component, the speed change component, the second planetary reduction component, and the output shaft. The compactness and high speed ratio of the planetary reduction structure enhance transmission stability, and the parallel shaft structure is used for load diversion and gear shifting to avoid gear wear.
It improves transmission stability and efficiency, enhances output torque, and ensures transmission reliability and stability, especially improving vehicle passability under long-term operation and harsh working conditions.
Smart Images
Figure CN224550717U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to a two-speed transmission for pure electric trucks, belonging to the field of pure electric transmission technology. Background Technology
[0002] Pure electric commercial vehicles typically employ a motor + transmission + drive axle as their drive system. The transmission primarily uses a parallel shaft structure or a planetary gear structure. The parallel shaft structure uses the movement of shift sleeves combined with gears of different outer diameters to achieve gear shifting. The planetary gear structure uses multi-stage planetary gear sets and clutches or brakes to change the speed ratio and achieve gear shifting. The parallel shaft structure suffers from a long transmission path, low transmission efficiency, large size, and difficult layout. The multi-planetary gear set structure has high assembly requirements and high costs for brakes and clutches. To shorten the transmission chain and reduce costs, a transmission structure with parallel shafts meshing with planetary gear sets is formed in the transmission. However, this still has shortcomings in transmission stability, gear wear rate, load distribution, and wheel-end torque enhancement. The reliability and stability of long-term transmission, as well as wheel-end traction performance under harsh conditions, need further improvement. Therefore, a power transmission route with higher transmission stability, higher transmission efficiency, and greater output torque is needed to ensure the vehicle's ability to pass through inclines or slippery road sections and its transmission reliability during long-term operation. Utility Model Content
[0003] The two-speed gearbox for pure electric trucks provided by this utility model improves the transmission stability of the transmission route at the input and output ends of the transmission component, increases output torque, ensures transmission stability, ensures uniformity of transmission load distribution, ensures reliability and stability of long-term transmission, effectively improves transmission efficiency, and forms a power transmission route with higher transmission stability, higher transmission efficiency, and greater output torque.
[0004] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A two-speed transmission for a pure electric truck includes multiple motors, a coupling assembly that couples the power of the multiple motors, a transmission assembly with two-speed function and a parallel shaft structure, and an output shaft. The characteristic is that the coupling assembly and the transmission assembly are coaxially connected through a planetary reduction assembly, and the transmission assembly and the output shaft are coaxially connected through a second planetary reduction assembly, forming a sequential transmission connection of the coupling assembly, the first planetary reduction assembly, the transmission assembly, the second planetary reduction assembly, and the output shaft.
[0005] Preferably, the coupling assembly includes an input shaft connected to the motor and a constant mesh gear meshing with the input shaft. The planetary reduction assembly includes a sun gear, planet gears meshing with the sun gear, a gear ring meshing with the planet gears, and a planet carrier that assembles the planet gears. The constant mesh gear and the sun gear are integrally formed on the same shaft. The gear ring is fixed to the housing of the gearbox, and the planet carrier is connected to the transmission assembly.
[0006] Preferably, the transmission assembly includes an intermediate shaft one connected to the planetary reduction assembly two, an intermediate shaft two parallel to the outer periphery of the intermediate shaft one and meshing with the planetary carrier one, a high-speed gear rotatably mounted on the intermediate shaft two, a low-speed gear rotatably mounted on the intermediate shaft two, and a shift sleeve splinedly fitted on the intermediate shaft two and located between the high-speed gear and the low-speed gear. The shift sleeve slides forward to engage with the high-speed gear and slides backward to engage with the low-speed gear. The high-speed gear and the low-speed gear mesh with the intermediate shaft one, respectively.
[0007] Preferably, there are two intermediate shafts, one of which is connected to the lubrication pump in the gearbox at its rear end, and the other of which extends out of the gearbox and is connected to the power take-off unit of the vehicle.
[0008] Preferably, the second planetary reduction assembly includes a second sun gear coaxially connected to the intermediate shaft, a second planet gear meshing with the second sun gear, a second gear ring whose inner ring meshes with the second planet gear and is fixed to the housing of the gearbox, and a second planet carrier that assembles the second planet gear. The second planet carrier is coaxially connected to the output shaft.
[0009] Preferably, it also includes a hydraulic retarder, and a retarding gear coaxially fixed on the output shaft and meshing with the hydraulic retarder.
[0010] The beneficial effects of this utility model are: This utility model discloses a two-speed transmission for pure electric trucks. A planetary reduction assembly (Part 1) is connected between the coupling assembly and the transmission assembly, and a planetary reduction assembly (Part 2) is connected between the transmission assembly and the output shaft. This forms a coaxial transmission line from the coupling assembly, planetary reduction assembly (Part 1), transmission assembly, planetary reduction assembly (Part 2), to the output shaft. Utilizing the compact structure and large speed ratio of planetary reduction gears, the axial dimensions of the transmission are reduced while effectively increasing output torque. Planetary reduction assembly (Part 1) first reduces and increases the torque of the coupled power from multiple motors before inputting it to the transmission assembly. Planetary reduction assembly (Part 2) reduces and increases the torque of the output power from the transmission assembly. By leveraging the high torque capacity and shock resistance of planetary reduction gears, the transmission stability at the input and output ends of the transmission assembly is improved, increasing output torque and ensuring transmission stability. Furthermore, the parallel shaft structure of the transmission assembly allows for load splitting during shifting, ensuring uniform load distribution and avoiding shifting power vacuum. This reduces gear wear during transmission, ensuring reliability and stability over long periods, effectively improving transmission efficiency, and forming a power transmission line with higher transmission stability, higher efficiency, and greater output torque. Attached Figure Description
[0011] Figure 1 This is a schematic diagram of the transmission structure of a two-speed gearbox for a pure electric truck in a specific implementation.
[0012] Figure 2 This is a schematic diagram showing the sequential transmission connection of the coupling component, planetary reduction component one, speed change component, travel reduction component two, and output shaft.
[0013] Figure 3 A schematic diagram of the transmission structure of a two-speed gearbox in a pure electric truck when the transmission components form a high-speed transmission.
[0014] Figure 4 A schematic diagram of the transmission structure of a two-speed gearbox in a pure electric truck when the transmission components form a low-speed gear transmission. Detailed Implementation
[0015] The following is combined Figures 1-4 The embodiments of this utility model will be described in detail below.
[0016] A two-speed transmission for a pure electric truck includes multiple motors 1, a coupling assembly 2 that power-couples the multiple motors 1, a transmission assembly 3 with two-speed function and a parallel shaft structure, and an output shaft 4. The characteristic feature is that the coupling assembly 2 and the transmission assembly 3 are coaxially connected via a planetary reduction assembly 5, and the transmission assembly 3 and the output shaft 4 are coaxially connected via a planetary reduction assembly 6, forming a sequential transmission connection of the coupling assembly 2, the planetary reduction assembly 5, the transmission assembly 3, the planetary reduction assembly 6, and the output shaft 4.
[0017] The two-speed transmission for the pure electric truck described above connects planetary reduction assembly 5 between coupling assembly 2 and transmission assembly 3, and planetary reduction assembly 6 between transmission assembly 3 and output shaft 4, forming a coaxial transmission line from coupling assembly 2, planetary reduction assembly 5, transmission assembly 3, planetary reduction assembly 6 to output shaft 4. Utilizing the compact structure and large speed ratio of planetary reduction gears, the axial dimension of the transmission is reduced while effectively increasing output torque. Planetary reduction assembly 5 first reduces and increases the torque of the coupled power from multiple motors before inputting it to transmission assembly 3, and planetary reduction assembly 6 further reduces the torque of the output shaft. The output power of the speed component 3 is reduced and torque is increased. By utilizing the high torque carrying capacity and shock resistance of the planetary reduction gear, the transmission stability of the transmission route at the input and output ends of the speed component 3 is improved, the output torque is increased, and the transmission stability is guaranteed. The parallel shaft structure of the speed component is used to split the load and form a split shift, which ensures the uniformity of the transmission load distribution and avoids the power vacuum during shifting. This reduces gear wear during transmission, ensures the reliability and stability of long-term transmission, effectively improves the transmission efficiency, and forms a power transmission route with higher transmission stability, higher transmission efficiency, and greater output torque.
[0018] The coupling assembly 2 includes an input shaft 21 connected to the motor and a constant mesh gear 22 meshing with the input shaft 21. The planetary reduction assembly 5 includes a sun gear 51, planet gears 52 meshing with the sun gear 51, a gear ring 53 with an inner ring meshing with the planet gears 52, and a planet carrier 54 mounting the planet gears 52. The constant mesh gear 22 and the sun gear 21 are coaxially integrally formed. The gear ring 53 is fixed to the gearbox housing, and the planet carrier 54 is connected to the transmission assembly 3. The input shaft 21 couples the power of the motor to the constant mesh gear 22, which drives the sun gear 21 to rotate. The power is reduced by the planetary reduction assembly 5 and transmitted from the planet carrier 54 to the transmission assembly 3. The planetary reduction assembly 5 reduces the coupled power of multiple electric motors and transmits the power to the transmission assembly 3, increasing the torque at the input end of the transmission assembly 3 and improving the power stability at the input end of the transmission assembly 3.
[0019] The transmission assembly 3 includes an intermediate shaft 31 connected to the planetary reduction assembly 6, an intermediate shaft 32 parallel to the outer periphery of the intermediate shaft 31 and meshing with the planetary carrier 54, a high-speed gear 33 rotatably mounted on the intermediate shaft 32, a low-speed gear 34 rotatably mounted on the intermediate shaft 32, and a shift sleeve 35 splinedly fitted on the intermediate shaft 32 and located between the high-speed gear 33 and the low-speed gear 34. The shift sleeve 35 slides forward to engage with the high-speed gear 33 and slides backward to engage with the low-speed gear 34. The high-speed gear 33 and the low-speed gear 34 respectively mesh with the intermediate shaft 31. Planetary carrier 54 drives intermediate shaft 32 to rotate. When shift sleeve 35 engages with high-speed gear 33, high-speed gear 33 drives intermediate shaft 31 to rotate. Intermediate shaft 31 drives planetary reducer 6 to operate, forming the high-speed transmission of the transmission assembly. When shift sleeve 35 engages with low-speed gear 34, low-speed gear 34 drives intermediate shaft 31 to rotate. Intermediate shaft 31 drives planetary reducer 6 to operate, forming the low-speed transmission of the transmission assembly. Intermediate shaft 32 is arranged parallel to the outer circumference of intermediate shaft 31. The arrangement of multiple intermediate shafts 32 forms a split of the transmission load, reduces gear load stress, reduces gear wear, and sequentially shifts gears on the shift sleeve 35 on intermediate shaft 32, forming a split shift, avoiding power vacuum during shifting, ensuring the reliability and stability of long-term transmission, and effectively improving transmission efficiency.
[0020] The system includes two intermediate shafts 32. One intermediate shaft 32 is connected to the lubrication pump 7 in the gearbox at its rear end, while the other intermediate shaft 32 extends out of the gearbox and is connected to the power take-off (PTO) 8 of the vehicle. The lubrication pump 7 is driven by the intermediate shaft 32 to lubricate the internal structure of the gearbox, and the PTO 8 is driven by the other intermediate shaft 32 to achieve auxiliary drive and improve power utilization.
[0021] The planetary reduction assembly 26 includes a sun gear 261 coaxially connected to the intermediate shaft 1 31, planet gears 262 meshing with the sun gear 261, a gear ring 2 63 with an inner ring meshing with the planet gears 261 and fixed to the gearbox housing, and a planet carrier 2 64 mounting the planet gears 262. The planet carrier 2 62 is coaxially connected to the output shaft 4. The intermediate shaft 1 31 drives the sun gear 2 61 to rotate, and the power is transmitted to the output shaft 4 after being reduced by the planetary reduction assembly 26. The planetary reduction assembly 26 reduces the output power of the transmission assembly 3 by torque and improves the stability of the output power.
[0022] This also includes a hydraulic retarder 9, with a retarding gear 41 coaxially fixed on the output shaft 4 and meshing with the hydraulic retarder 9. The hydraulic retarder 9 is installed at the rear end of the gearbox and uses the hydraulic damper 9 to decelerate the output shaft 4. When descending long slopes, the hydraulic damper 9 reduces the speed of the output shaft 4, thereby reducing the wheel end speed, providing auxiliary braking for the vehicle, and improving safety performance.
[0023] The technical solutions of the embodiments of this utility model have been fully described above with reference to the accompanying drawings. It should be noted that the described embodiments are only a part of the embodiments of this utility model. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.
Claims
1. A two-speed transmission for a pure electric truck, comprising multiple motors, a coupling assembly for power coupling of the multiple motors, a transmission assembly with two-speed shifting function and a parallel shaft structure, and an output shaft, characterized in that: The coupling component and the speed change component are coaxially connected through a planetary reduction component, and the speed change component and the output shaft are coaxially connected through a second planetary reduction component, forming a sequential transmission connection of the coupling component, the first planetary reduction component, the speed change component, the second planetary reduction component, and the output shaft.
2. The two-speed transmission for pure electric trucks according to claim 1, characterized in that: The coupling assembly includes an input shaft connected to the motor and a constant mesh gear meshing with the input shaft. The planetary reduction assembly includes a sun gear, planet gears meshing with the sun gear, a gear ring meshing with the planet gears, and a planet carrier that assembles the planet gears. The constant mesh gear and the sun gear are integrally formed on the same shaft. The gear ring is fixed to the gearbox housing, and the planet carrier is connected to the transmission assembly.
3. The two-speed transmission for pure electric trucks according to claim 2, characterized in that: The transmission assembly includes an intermediate shaft 1 connected to the planetary reduction assembly 2, an intermediate shaft 2 parallel to the outer periphery of the intermediate shaft 1 and meshing with the planetary carrier 1, a high-speed gear rotatably mounted on the intermediate shaft 2, a low-speed gear rotatably mounted on the intermediate shaft 2, and a shift sleeve splinedly fitted on the intermediate shaft 2 and located between the high-speed gear and the low-speed gear. The shift sleeve slides forward to engage with the high-speed gear and slides backward to engage with the low-speed gear. The high-speed gear and the low-speed gear mesh with the intermediate shaft 1 respectively.
4. The two-speed transmission for pure electric trucks according to claim 3, characterized in that: There are two intermediate shafts. The rear end of one intermediate shaft is connected to the lubrication pump in the gearbox, and the other intermediate shaft extends out of the gearbox and is connected to the vehicle's power take-off.
5. The two-speed transmission for pure electric trucks according to claim 3, characterized in that: The planetary reduction assembly 2 includes a sun gear 2 coaxially connected to the intermediate shaft, planet gears 2 meshing with the sun gear 2, a gear ring 2 whose inner ring meshes with the planet gears 2 and is fixed to the gearbox housing, and a planet carrier 2 that assembles the planet gears 2. The planet carrier 2 is coaxially connected to the output shaft.
6. The two-speed transmission for pure electric trucks according to claim 1, characterized in that: It also includes a hydraulic retarder, and a retarding gear that meshes with the hydraulic retarder is coaxially fixed on the output shaft.