Wide-body mine car electric drive axle and driving method thereof

Abstract

An electric drive axle of a wide-body mine car comprises motors, speed reduction assemblies in one-to-one correspondence with the motors, a speed change assembly with a gear shifting and speed changing function, a differential mechanism, a half shaft assembled on the differential mechanism and a wheel end planet row installed at the end of the half shaft, and the motors, the speed reduction assemblies, the speed change assembly, the differential mechanism, the half shaft and the wheel end planet row are sequentially in transmission connection. The differential mechanism is characterized in that the number of the speed reduction assemblies is four, the speed reduction assemblies are distributed on the two sides of the half shaft in a rectangular mode, the two speed reduction assemblies aligned in the half shaft direction are coaxially connected through the speed change assemblies respectively, and the two speed change assemblies are symmetrically arranged on the two sides of the half shaft and aligned with the differential mechanism in the radial direction. The transmission structure is simplified, the transmission path is effectively shortened, the axial size is shortened, the unsprung mass is reduced, the transmission efficiency is improved, power distribution is optimized, and the requirements for abrupt slope continuous output and level road economy are met while the loading standard is met. The invention further provides a driving method of the wide-body mine car electric drive axle.

Description

Technical Field

[0001] The present invention relates to an electric drive axle of a wide-body mining car and a driving method thereof, belonging to the technical field of pure electric variable speed drive. Background Art

[0002] In the mining and transportation sector, wide-body mining trucks are core equipment for transporting bulk materials. Due to the demands of fully loaded loads and continuous grade travel, their electric drive axles must be powered by multiple motors to increase power density and wheel-end torque. Purely electric heavy-duty commercial trucks typically utilize both central electric drive and electric drive axles to achieve vehicle power transmission. Compared to central electric drive, electric drive axles contribute more to vehicle layout space and offer a higher level of integration, leading to their wider application. The transmission efficiency and structural design of electric drive axles used in medium- and heavy-duty trucks directly impact vehicle performance. Existing electric drive axle configurations include parallel axis, coaxial, and planetary gear types. Existing parallel-axis electric drive axles all suffer from pain points such as long transmission chains, high energy loss, and high maintenance costs. Furthermore, the unbalanced power structure layout leads to poor load-bearing capacity and high safety risks. Coaxial electric drive axles have shorter transmission chains, but can generally only be equipped with two motors, which cannot meet load standards. They also suffer from defects such as insufficient torque density and poor adaptability to working conditions. They face multiple challenges in climbing heavy-load slopes, adapting to complex road conditions, and improving energy efficiency. Planetary gear electric drive axles use a multi-stage planetary gearbox and multiple clutches or brakes to form different speed ratios for gear shifting, effectively increasing wheel-end torque and offering a compact structure. However, the structural and control costs are relatively high. This solution improves the electric drive axle from several aspects, including the power transmission path and distribution method, the electric drive axle structure, and the control strategy, to meet the drive requirements of wide-body mining vehicles. Summary of the Invention

[0003] The electric drive axle for wide-body mine vehicles provided by this invention simplifies the transmission structure and effectively shortens the transmission path. Two sets of coaxially coupled dual-motor power transmission structures are symmetrically distributed on either side of the axle axis. This shortens the axial dimension, reduces unsprung mass, improves transmission efficiency, and optimizes power distribution. This ensures that the electric drive axle meets load standards while balancing the requirements of continuous output on steep slopes and economic efficiency on flat roads. The invention also provides a driving method for the electric drive axle for wide-body mine vehicles.

[0004] In order to achieve the above object, the technical solution adopted by the present invention is: The electric drive axle of a wide-body mining car includes a motor, a reduction assembly corresponding to the motor, a speed change assembly with a gear shifting and speed change function, a differential, a half-shaft assembled on the differential, and a wheel-end planetary gear set mounted on the end of the half-shaft. The motor, the reduction assembly, the speed change assembly, the differential, the half-shaft and the wheel-end planetary gear set are sequentially connected in a transmission manner. The characteristic is that there are four groups of reduction assemblies, which are distributed in a rectangular shape on both sides of the half-shaft. Two groups of reduction assemblies aligned along the direction of the half-shaft are coaxially connected through a group of speed change assemblies respectively. The two groups of speed change assemblies are symmetrically arranged on both sides of the half-shaft and aligned radially with the differential.

[0005] Preferably, the reduction assembly is a high-speed planetary gear, including a sun gear connected to the motor shaft end, a planetary carrier, a planetary shaft assembled on the planetary carrier, a planetary gear 1 engaged with the sun gear and fixed on the planetary shaft, a ring gear fixed to the bridge housing, a planetary gear 2 fixed on the planetary shaft and engaged with the ring gear, and the output end of the planetary carrier is connected to the speed change assembly.

[0006] Preferably, the speed change assembly includes an intermediate shaft connected to the output end of the planetary carrier, a shift gear coaxially fixed on the intermediate shaft, a shift sleeve slidably assembled on the shift gear in the axial direction, a first-speed driving gear rotatably mounted on the intermediate shaft, and a second-speed driving gear rotatably mounted on the intermediate shaft, the first-speed driving gear and the second-speed driving gear are respectively located on both sides of the shift sleeve, the shift sleeve slides to the left to engage with the first-speed driving gear, and slides to the right to engage with the second-speed driving gear, and the first-speed driving gear and the second-speed driving gear are respectively engaged with the differential.

[0007] Preferably, the shift gear sleeve slides to the left and combines with the first gear driving gear to form the first gear transmission of the speed change assembly, and the shift gear sleeve slides to the right and combines with the second gear driving gear to form the second gear transmission of the speed change assembly.

[0008] Preferably, the differential case of the differential is equipped with a first-gear driven gear meshing with the first-gear driving gear and a second-gear driven gear meshing with the second-gear driving gear, and the first-gear driven gear and the second-gear driven gear are respectively arranged at the left and right ends of the differential case.

[0009] Preferably, the intermediate shaft is parallel to the half shaft, and both ends of the intermediate shaft are coaxially connected to the output end of the planet carrier through splines.

[0010] Preferably, the first-gear driven gear and the second-gear driven gear are both integrally formed with the differential housing, and the differential housing is aligned with the shift gear in the radial direction.

[0011] The above-mentioned driving method of the electric drive axle of the wide-body mining car is characterized by: When the vehicle is lightly loaded, two motors are used to drive it, and the reduction assemblies corresponding to the two motors are aligned along the half-axle direction; When the vehicle is heavily loaded, four motors are used to drive it, and when speed change is required, the two sets of speed change components are shifted in sequence.

[0012] The beneficial effects of the present invention are: The wide-body mining car electric drive axle of the present invention has four groups of reduction assemblies distributed in a rectangular shape on both sides of the half-axles. Two groups of reduction assemblies aligned along the half-axles are connected by a group of speed change assemblies. Each group of speed change assemblies couples the power of two motors, realizing coaxial coupling of dual-motor power, simplifying the transmission structure, effectively shortening the transmission path, and transmitting power to the differential through the speed change assembly. The differential drives the half-axles to rotate to form wheel-end drive. The speed change assembly and the differential are aligned radially, so that the four groups of reduction assemblies and four motors form a rectangular distribution centered on the differential on both sides of the half-axles, forming a transmission structure with two groups of coaxial coupling of dual-motor power symmetrically distributed on both sides of the axle axis, making full use of the vehicle axis space, reducing the radial dimension of the bridge housing, shortening the axial dimension, and reducing the unsprung mass. The distribution and number of motors participating in the drive can be adjusted according to the vehicle load and road conditions, and speed shifting can be formed through the speed change assembly, thereby improving transmission efficiency and optimizing power distribution, so as to realize a control strategy for dynamic driving according to working conditions, while meeting the load standard and taking into account the requirements of continuous output on steep slopes and economic performance on flat roads. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] Figure 1 It is a schematic diagram of the transmission structure of the electric drive axle of the wide-body mining car in a specific implementation manner.

[0014] Figure 2 This is a schematic diagram of the transmission structure of the electric drive axle of a wide-body mining car when the shift sleeve slides to the left and engages with the first-gear driving gear.

[0015] Figure 3 This is a schematic diagram of the transmission structure of the electric drive axle of a wide-body mining car when the shift sleeve slides to the left and engages with the second-gear driving gear. DETAILED DESCRIPTION

[0016] The following combination Figures 1-3 The embodiments of the present invention are described in detail.

[0017] The electric drive axle of a wide-body mining car includes a motor 1, a reduction assembly 2 corresponding to the motor 1, a speed change assembly 3 with a gear shifting function, a differential 4, a half shaft 5 assembled on the differential 4 and a wheel-end planetary gear set 6 mounted on the end of the half shaft 5. The motor 1, the reduction assembly 2, the speed change assembly 3, the differential 4, the half shaft 5 and the wheel-end planetary gear set 6 are sequentially connected in a transmission manner. It is characterized in that: there are four groups of reduction assemblies 2, and they are distributed in a rectangular shape on both sides of the half shaft 5. Two groups of reduction assemblies 2 aligned along the half shaft direction are coaxially connected through a group of speed change assembly 3 respectively. The two groups of speed change assemblies 3 are symmetrically arranged on both sides of the half shaft 5 and aligned radially with the differential 4.

[0018] The wide-body mine car electric drive axle described above has four groups of reduction assemblies 2 distributed in a rectangular shape on both sides of the half-axle. The two groups of reduction assemblies 2 aligned along the half-axle direction are connected through a group of speed change assemblies 3. Each group of speed change assemblies 3 forms a coupling of the power of the two motors 1, realizing the coaxial coupling of the dual-motor power, simplifying the transmission structure, effectively shortening the transmission path, and transmitting the power to the differential 4 through the speed change assembly 3. The differential 4 drives the half-axle 5 to rotate to form a wheel-end drive. The speed change assembly 3 and the differential 4 are aligned radially, so that the four groups of reduction assemblies 2 and the four motors 1 are on both sides of the half-axle 5. A rectangular distribution with the differential 4 as the center is formed on both sides, forming a transmission structure with two sets of dual-motor power coaxial coupling symmetrically distributed on both sides of the axle axis, making full use of the vehicle-car axis space, reducing the radial dimension of the bridge housing, shortening the axial dimension, and reducing the unsprung mass. The distribution and number of motors involved in the drive can be adjusted according to the vehicle load and road conditions, and speed shifting can be formed through the speed change component to improve transmission efficiency and optimize power distribution to achieve a control strategy for dynamic driving according to working conditions, while meeting the load standard and taking into account the continuous output on steep slopes and the economic needs of flat roads.

[0019] The reduction assembly 2 is a high-speed planetary gear set, comprising a sun gear 21 connected to the shaft end of the motor 1, a planet carrier 22, a planetary shaft 23 mounted on the planet carrier 22, a planetary gear 1 24 meshing with the sun gear 31 and fixed to the planetary shaft 23, a ring gear 25 fixed to the axle housing, and a planetary gear 26 fixed to the planetary shaft 23 and meshing with the ring gear 25. The output end of the planetary gear set 22 is connected to the speed change assembly 3. The motor 1 drives the sun gear 21 to rotate, which in turn drives the planetary gear 1 24. The planetary gear 1 24 drives the planetary shaft 23 and the planetary gear 2 26 to rotate synchronously. The planetary gear 26 rotates within the ring gear 25, driving the planetary gear set 22 to rotate. The planetary gear set 22 transmits power to the speed change assembly 3. The use of a high-speed planetary gear set with two planetary gears can not only increase the speed ratio and improve the deceleration and torque-increasing characteristics, but also does not increase the axial size, further improving the structural compactness of the electric drive axle.

[0020] The transmission assembly 3 includes an intermediate shaft 31 connected to the output end of the planetary carrier 22, a shift gear 32 coaxially fixed to the intermediate shaft 31, a shift sleeve 33 slidably assembled on the shift gear 32 along the axial direction, a first-speed driving gear 34 rotatably mounted on the intermediate shaft 31, and a second-speed driving gear 35 rotatably mounted on the intermediate shaft 31. The first-speed driving gear 34 and the second-speed driving gear 35 are respectively located on both sides of the shift sleeve 33. The shift sleeve 33 slides to the left to engage with the first-speed driving gear 34 and slides to the right to engage with the second-speed driving gear 35. The first-speed driving gear 34 and the second-speed driving gear 35 are respectively engaged with the differential. The output ends of the planetary carriers 22 in the reduction assemblies 2 on the left and right sides of the speed change assembly 3 are respectively connected to the ends of the intermediate shaft 33. The power of the two motors is transmitted to the intermediate shaft 33 after being reduced by the reduction assembly 2, realizing coaxial coupling of the power of the dual motors, simplifying the transmission structure, and effectively shortening the transmission path. When the shift sleeve 33 is in the neutral position and is not engaged with the first gear driving gear 34 or the second gear driving gear 35, the power of the intermediate shaft 31 cannot be transmitted to the differential 4. The power can only be transmitted to the differential 4 when the shift sleeve 33 is engaged with the first gear main gear 34 or the second gear driving gear 35.

[0021] The shift sleeve 33 slides leftward and engages with the first-gear driving gear 34 to form the first gear transmission of the transmission assembly. The shift sleeve 33 slides rightward and engages with the second-gear driving gear 35 to form the second gear transmission of the transmission assembly. When the shift gear 33 slides leftward and engages with the first-gear driving gear 34, the transmission assembly 3 generates first gear power, which is transmitted to the differential 4. First gear power has higher torque and lower speed. When the shift sleeve 33 slides rightward and engages with the second-gear driving gear 35, the transmission assembly 3 generates second gear power, which is transmitted to the differential 4. Second gear power has lower torque and higher speed. The transmission assembly 3 has a simple shifting structure. Gear shifting is achieved by sliding the shift sleeve 33 on the shift gear 32, resulting in simple control and low cost. Control of the transmission assembly 3, combined with adjustment of the distribution and number of motors involved in the drive, can meet driving requirements under various operating conditions, implementing a dynamic driving control strategy tailored to the operating conditions. This balances sustained output on steep slopes with economical operation on flat roads while meeting load standards.

[0022] The differential 4 is mounted on a differential case 41 with a first-gear driven gear 42 meshing with the first-gear driving gear 34 and a second-gear driven gear 43 meshing with the second-gear driving gear 35. The first-gear driven gear 42 and the second-gear driven gear 43 are respectively disposed on the left and right ends of the differential case 41. When the shift gear 33 slides leftward and engages with the first-gear driving gear 34, the power of the intermediate shaft 31 is transmitted to the differential 4 via the first-gear driving gear 34 and the first-gear driven gear 42. When the shift gear 33 slides rightward and engages with the second-gear driving gear 35, the power of the intermediate shaft 31 is transmitted to the differential 4 via the second-gear driving gear 35 and the second-gear driven gear 43.

[0023] Among them, the intermediate shaft 31 is parallel to the half shaft 5, and the two ends of the intermediate shaft 31 are coaxially connected to the output end of the planetary carrier 22 through splines, so that the reduction assembly 2 and the speed change assembly 3 form a detachable transmission connection, forming a modular connection structure, which is convenient for assembly and disassembly maintenance. The structures of the four groups of reduction assemblies 2 are exactly the same, and the structures of the two groups of speed change assemblies are exactly the same, and they are all standardized shafts and teeth, with a high standardization rate, which effectively shortens maintenance time.

[0024] Among them, the first-gear driven gear 42 and the second-gear driven gear 43 are both integrally formed with the differential housing 41, which improves the structural strength of the differential housing 41 and ensures transmission reliability. The differential housing 41 is radially aligned with the shift gear 32, so that the differential 4 is located at the center of the two speed change components 2, ensuring that the four groups of reduction components 2 and the four motors 1 form a rectangular distribution centered on the differential 4 on both sides of the half-shaft 5. The assembly position of the intermediate shaft 31 relative to the differential 4 is determined by aligning the differential 4 with the shift gear 32, and thus the assembly position of the reduction components 2 on the left and right sides of the intermediate shaft 31 is determined according to the assembly position of the intermediate shaft 31, thereby improving the assembly efficiency of the electric drive axle structure, ensuring the reliability of the assembly position, and thus improving the transmission reliability.

[0025] The present invention also protects the driving method of the above-mentioned wide-body mining car electric drive axle, which is characterized by: When the vehicle is lightly loaded, two motors 1 are used to drive the vehicle, and the reduction assemblies 2 corresponding to the two motors are aligned along the half-axis direction; When the vehicle is heavily loaded, four motors 1 are used to drive the vehicle. When speed change is required, the two sets of speed change components 3 are shifted in sequence.

[0026] The driving method described above uses two motors to drive when the vehicle is lightly loaded, and the reduction assemblies 2 corresponding to the two motors are located on the same side of the half-shaft 5. The two groups of reduction assemblies 2 are connected through the speed change assembly 3 to couple the power of the two motors. That is, only one group of dual-motor coaxially coupled transmission structures is used for driving, while the other group of dual-motor coaxially coupled transmission structures does not participate in the driving. This shortens the transmission path, improves transmission efficiency, places the motors in a high-efficiency range, reduces energy consumption, and meets the economic needs of flat roads. When the vehicle is heavily loaded, four motors are used to drive, meeting the high torque requirements of the wheel ends, improving power density, and meeting the continuous output requirements on steep slopes. At the same time, the two groups of speed change assemblies 3 shift gears in sequence to meet the driving requirements under heavy-load acceleration or high-load escape, avoiding power interruption and impact during the shifting process. The distribution and number of motors involved in the drive are adjusted according to the vehicle load and road conditions, and speed shifting is formed through the speed change assembly 3 to implement a control strategy for dynamic driving according to the working conditions.

[0027] The above fully describes the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the embodiments described are only part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. The electric drive axle of a wide-body mining car includes a motor, a reduction assembly corresponding to the motor, a transmission assembly with a gear shifting function, a differential, a half-shaft assembled on the differential, and a wheel-end planetary gear set mounted on the end of the half-shaft. The motor, reduction assembly, transmission assembly, differential, half-shaft and wheel-end planetary gear set are sequentially connected in a transmission manner and are characterized by: There are four groups of reduction assemblies, which are distributed in a rectangular shape on both sides of the half-shaft. The two groups of reduction assemblies aligned along the half-shaft direction are coaxially connected through a group of speed change assemblies. The two groups of speed change assemblies are symmetrically arranged on both sides of the half-shaft and radially aligned with the differential.

2. The electric drive axle of a wide-body mining car according to claim 1, characterized in that: The reduction assembly is a high-speed planetary gear, including a sun gear connected to the motor shaft end, a planetary carrier, a planetary shaft assembled on the planetary carrier, a planetary gear 1 engaged with the sun gear and fixed on the planetary shaft, a ring gear fixed to the bridge housing, a planetary gear 2 fixed on the planetary shaft and engaged with the ring gear, and the output end of the planetary carrier is connected to the speed change assembly.

3. The electric drive axle of a wide-body mining car according to claim 2, characterized in that: The transmission assembly includes an intermediate shaft connected to the output end of the planetary carrier, a shift gear coaxially fixed on the intermediate shaft, a shift sleeve slidably assembled on the shift gear in the axial direction, a first-speed driving gear rotatably mounted on the intermediate shaft, and a second-speed driving gear rotatably mounted on the intermediate shaft. The first-speed driving gear and the second-speed driving gear are respectively located on both sides of the shift sleeve. The shift sleeve slides to the left to engage with the first-speed driving gear and slides to the right to engage with the second-speed driving gear. The first-speed driving gear and the second-speed driving gear are respectively engaged with the differential.

4. The electric drive axle of a wide-body mining vehicle according to claim 3, characterized in that: The shift gear sleeve slides to the left and combines with the first gear driving gear to form the first gear transmission of the speed change assembly, and the shift gear sleeve slides to the right and combines with the second gear driving gear to form the second gear transmission of the speed change assembly.

5. The electric drive axle of a wide-body mining vehicle according to claim 3, characterized in that: The differential case of the differential is equipped with a first gear driven gear meshing with the first gear driving gear and a second gear driven gear meshing with the second gear driving gear. The first gear driven gear and the second gear driven gear are respectively arranged at the left and right ends of the differential case.

6. The electric drive axle of a wide-body mining vehicle according to claim 3, characterized in that: The intermediate shaft is parallel to the half shaft, and both ends of the intermediate shaft are coaxially connected to the output end of the planet carrier through splines.

7. The electric drive axle of a wide-body mining vehicle according to claim 5, characterized in that: The first-speed driven gear and the second-speed driven gear are both integrally formed with the differential housing, and the differential housing is aligned with the shift gear in the radial direction.

8. The driving method of the electric drive axle of a wide-body mining vehicle according to any one of claims 1 to 7, characterized in that: When the vehicle is lightly loaded, two motors are used to drive it, and the reduction assemblies corresponding to the two motors are aligned along the half-axle direction; When the vehicle is heavily loaded, four motors are used to drive it, and when speed change is required, the two sets of speed change components are shifted in sequence.

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