High-efficiency four-gear electric drive axle transmission system

Abstract

Provided is a high-efficiency four-gear electric drive axle transmission system, comprising: a first input unit; an intermediate shaft, which is fixedly connected with a first gear shifter and a second gear shifter and is sleeved with a first gear shifting driven gear, a second gear shifting driven gear and a third gear shifting driving gear in a rotatable manner; a first transmission unit, comprising a second parallel shaft and a third gear shifting driven gear and a fourth gear shifting driving gear fixedly connected to the second parallel shaft; and a differential, which is provided with a first power output half shaft and a second power output half shaft and has a fourth gear shifting driven gear sleeved on the outer periphery of the differential housing, the fourth gear shifting driving gear is used for transmitting power to the fourth gear shifting driven gear, and the second gear shifter is selectively combined with the third gear shifting driving gear or the fourth gear shifting driven gear for transmitting power from the intermediate shaft to the third gear shifting driving gear or the fourth gear shifting driven gear. The gear shifting interval ratio between the four gears is greatly reduced, the gear shifting impact is reduced, and the working efficiency of the motor is improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of new energy automobile parts, and particularly relates to a high-efficiency four-gear electric drive axle transmission system. BACKGROUND

[0002] New energy vehicles are increasingly valued by the country. At present, most electric drive axles are single-gear or two-gear structures. The single-gear electric drive axle can reduce the complexity of the gearbox, and only one reduction mechanism needs to be configured. However, the demand for the motor is relatively high, and the motor needs to provide a large enough torque and high speed in order to adapt to the climbing ability and high speed requirements of the vehicle. The size of the motor is relatively large, and the cost of the motor and the electric control is relatively high. Moreover, because there is no gear adjustment, the motor operates in a small efficient interval, and the overall efficiency of the motor is not high. The two-gear electric drive axle can greatly improve the problems caused by the single-gear electric drive axle. The low-speed gear is configured with a large transmission ratio to provide enough power for the vehicle, and the high-speed gear is configured with a small transmission ratio to provide enough speed for the vehicle. The demand for the motor is reduced, the size of the motor is reduced, and the cost of the motor and the electric control is reduced. However, when the actual speed ratio is configured, in order to balance the highest speed and the maximum climbing power requirements, the interval ratio between the high and low gears needs to be large, which brings about the unevenness of the vehicle during gear shifting, and there is a significant jerk. Moreover, the time ratio of the vehicle working at extremely low speed and extremely high speed is very small, so that the vehicle will appear to be insufficient in speed when using the low gear and insufficient in power when using the high gear during most of the driving conditions.

[0003] Therefore, it is necessary to study a high-efficiency four-gear electric drive axle transmission system to solve one or more of the above technical problems. SUMMARY

[0004] To solve at least one of the above technical problems, according to an aspect of the present application, a high-efficiency four-gear electric drive axle transmission system is provided. The system is compact and symmetrical in structure, small in size, and can be arranged on mainstream commercial vehicles. The suspension form can be a steel plate spring type or an air suspension type. Two sets of gear shifting mechanisms are used to realize the function of four gears. The low gear matches a large transmission ratio to provide a large enough torque for the vehicle during starting, escaping, climbing and other working conditions. The high gear matches a small transmission ratio to provide a high enough speed for the vehicle during high-speed driving and empty vehicle working conditions. The two middle gears have a transmission ratio between the low gear and the high gear to provide a power demand with a higher torque and a higher speed for the vehicle under non-extreme working conditions. The gear shifting interval ratio between the four gears is greatly reduced compared with the current mainstream two-gear electric drive axle, which can reduce the gear shifting impact and provide vehicle comfort, and can also improve the working efficiency of the motor and increase the cruising range of the vehicle.

[0005] More specifically, a high-efficiency four-gear electric drive axle transmission system comprises:

[0006] The first input unit comprises: an input driving gear driven by the first motor; a first parallel shaft fixedly connected with a second shift driving gear, an input driven gear and the first shift driving gear in sequence, the input driving gear being used for transmitting power to the input driven gear;

[0007] The intermediate shaft is fixedly connected with the first shift device and the second shift device and rotatably sleeved with the first shift driven gear, the second shift driven gear and the third shift driving gear, the second shift driving gear being used for transmitting power to the second shift driven gear, the first shift driving gear being used for transmitting power to the first shift driven gear, the first shift device being selectively combined with the second shift driven gear or the first shift driven gear for transmitting power from the second shift driven gear or the first shift driven gear to the intermediate shaft;

[0008] The first transmission unit comprises a second parallel shaft and a third shift driven gear and a fourth shift driving gear fixedly connected to the second parallel shaft, the third shift driving gear being used for transmitting power to the third shift driven gear; and

[0009] The differential is provided with a first power output half shaft and a second power output half shaft and the housing of the differential is sleeved with a fourth shift driven gear, the fourth shift driving gear being used for transmitting power to the fourth shift driven gear, the second shift device being selectively combined with the third shift driving gear or the fourth shift driven gear for transmitting power from the intermediate shaft to the third shift driving gear or the fourth shift driven gear;

[0010] The first power output half shaft passes through the intermediate shaft and is used for transmitting power to the first wheel, and the second power output half shaft is used for transmitting power to the second wheel.

[0011] According to still another aspect of the present application, the first power output half shaft is directly connected or connected via a first wheel-side reduction planetary set to the first wheel, and the second power output half shaft is directly connected or connected via a second wheel-side reduction planetary set to the second wheel.

[0012] According to still another aspect of the present application, the first parallel shaft and the second parallel shaft are distributed on both sides of the intermediate shaft.

[0013] According to still another aspect of the present application, the differential, the second shift device, the third shift driving gear, the first shift driven gear, the first shift device and the second shift driven gear are arranged in sequence in the direction in which the first power output half shaft extends.

[0014] According to still another aspect of the present application, the first shift device and the second shift device each comprise a gear hub and a shift element.

[0015] According to another aspect of the present application, the high-efficiency four-gear electric drive axle transmission system further comprises a second input unit having the same structure as the first input unit.

[0016] According to another aspect of the present application, the high-efficiency four-gear electric drive axle transmission system further comprises a second transmission unit having the same structure as the first transmission unit.

[0017] According to another aspect of the present application, the end of the second parallel shaft is connected to the PTO device through a connecting and disconnecting mechanism.

[0018] According to another aspect of the present application, a high-efficiency four-gear electric drive axle transmission system is provided, characterized in comprising:

[0019] The first input unit comprises: an input driving gear driven by the first motor; a first parallel shaft connected with an input driven gear, a first gear shifting driving gear, a first gear shifter and a second gear shifting driving gear in sequence, the input driving gear being used for transmitting power to the first parallel shaft through the input driven gear, the first gear shifter being selectively combined to the first gear shifting driving gear or the second gear shifting driving gear for transmitting power from the first parallel shaft to the first gear shifting driving gear or the second gear shifting driving gear.

[0020] The intermediate shaft is fixedly connected with a second gear shifter, a first gear shifting driven gear and a second gear shifting driven gear and is rotatably sleeved with a third gear shifting driving gear, the first gear shifting driving gear being used for transmitting power to the intermediate shaft through the first gear shifting driven gear, the second gear shifting driving gear being used for transmitting power to the intermediate shaft.

[0021] The first transmission unit comprises a second parallel shaft and a third gear shifting driven gear and a fourth gear shifting driving gear fixedly connected to the second parallel shaft, the third gear shifting driving gear being used for transmitting power to the third gear shifting driven gear; and

[0022] The differential is provided with a first power output half shaft and a second power output half shaft and the housing of the differential is sleeved with a fourth gear shifting driven gear, the fourth gear shifting driving gear being used for transmitting power to the fourth gear shifting driven gear, the second gear shifter being selectively combined to the third gear shifting driving gear or the fourth gear shifting driven gear for transmitting power from the intermediate shaft to the third gear shifting driving gear or the fourth gear shifting driven gear.

[0023] The first power output half shaft passes through the intermediate shaft and is used for transmitting power to the first wheel, and the second power output half shaft is used for transmitting power to the second wheel.

[0024] According to another aspect of the present application, the high-efficiency four-gear electric drive axle transmission system further comprises a second input unit and / or a second transmission unit, the second input unit has the same structure as the first input unit, and the second transmission unit has the same structure as the first transmission unit.

[0025] The present application can achieve one or more of the following technical effects:

[0026] 1. The four-shaft arrangement can adjust the axial distance between the first and second shafts and the second and third shafts, respectively, can more reasonably design the gear parameters, and the first parallel shaft and the second parallel shaft are distributed on both sides of the intermediate shaft, so that the electric drive axle structure tends to be symmetrical and does not produce too much bias.

[0027] 2. The double-shifter structure can realize four-gear function, the low gear matches a large transmission speed ratio, provides a large enough torque for the vehicle in the starting, escaping, climbing and other working conditions, the high gear matches a small transmission speed ratio, provides a high enough speed for the vehicle in the high-speed running, empty vehicle and other working conditions, the middle two gears match two high-efficiency transmission ratios between the low gear and the high gear according to the common working conditions of the vehicle, provide a torque higher and speed higher power demand for the vehicle in the non-extreme working conditions. The shift ratio between the four gears is greatly reduced compared with the two gears, which can not only reduce the shift impact and provide vehicle comfort, but also improve the working efficiency of the motor and increase the cruising range of the vehicle.

[0028] 3. When the second shifter moves to the left and engages with the engaging teeth on the fourth shifter driven gear, no matter whether the first shifter engages with the engaging teeth A on the second shifter driven gear or the engaging teeth B on the first shifter driven gear, the power on the motor is transmitted to the intermediate shaft, and then the power of the intermediate shaft is directly transmitted to the differential through the second shifter, without passing through the third and fourth shifter gear pairs, which can reduce two-stage transmission and improve mechanical transmission efficiency.

[0029] 4. The intermediate transmission box part is all cylindrical fixed shaft gear, and the planetary row is placed on the wheel edge, which reduces the difficulty of transmission box structure design, processing and assembly. BRIEF DESCRIPTION OF DRAWINGS

[0030] The present application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0031] Figure 1 The schematic diagram of the high-efficiency four-gear electric drive axle transmission system according to the first preferred embodiment of the present application.

[0032] Figures 2-5 The power flow schematic diagram of the four gears of the high-efficiency four-gear electric drive axle transmission system in Figure 1

[0033] ​Figure 6 A schematic diagram of a high-efficiency four-gear electric drive axle transmission system according to a second preferred embodiment of the present application.

[0034] Figure 7 A schematic diagram of a high-efficiency four-gear electric drive axle transmission system according to a third preferred embodiment of the present application.

[0035] Figure 8 A schematic diagram of a high-efficiency four-gear electric drive axle transmission system according to a fourth preferred embodiment of the present application.

[0036] Figure 9 A schematic diagram of a high-efficiency four-gear electric drive axle transmission system according to a fifth preferred embodiment of the present application. DETAILED DESCRIPTION

[0037] The preferred embodiments of the present application will be described herein below with reference to the accompanying drawings, in which the specific embodiments of the present application are illustrated. The specific embodiments are illustrative of specific arrangements of the present application, and do not limit the scope of the present application, and various modifications and changes can be made without departing from the spirit and scope of the present application, which should be included within the scope of the present application.

[0038] Example 1

[0039] According to a preferred embodiment of the present application, referring to Figures 1-5 , a high-efficiency four-gear electric drive axle transmission system is provided, characterized by comprising:

[0040] a first input unit, comprising: an input driving gear 13 driven by a first motor 11 (e.g. via a motor shaft 12); a first parallel shaft 14 fixedly connected with a second shift driving gear 17, an input driven gear 16 and a first shift driving gear 15 in sequence, the input driving gear 13 being configured to transmit power to the input driven gear 16;

[0041] a middle shaft 22 fixedly connected with a first shift device (the first shift device comprising a gear hub 21 and a shift element 20) and a second shift device (the second shift device comprising a gear hub 23 and a shift element 24) and rotatably sleeved with a first shift driven gear 18, a second shift driven gear 19 and a third shift driving gear 26, the second shift driving gear 17 being configured to transmit power to the second shift driven gear 19, the first shift driving gear 15 being configured to transmit power to the first shift driven gear 18, the first shift device being selectively coupled to the second shift driven gear 19 or the first shift driven gear 18 to transmit power from the second shift driven gear 19 or the first shift driven gear 18 to the middle shaft 22;

[0042] The first transmission unit comprises a second parallel shaft 30, a third shift driven gear 29 and a fourth shift driving gear 28 fixedly connected to the second parallel shaft 30, and the third shift driving gear 26 is used for transmitting power to the third shift driven gear 29; and

[0043] The differential 27 is provided with a first power output half shaft 36 and a second power output half shaft 31, and the differential 27 is provided with a fourth shift driven gear 25 outside the shell, the fourth shift driving gear 28 is used for transmitting power to the fourth shift driven gear 25, and the second shift gear is selectively combined with the third shift driving gear 26 or the fourth shift driven gear 25 for transmitting power from the intermediate shaft 22 to the third shift driving gear 26 or the fourth shift driven gear 25.

[0044] The first power output half shaft 36 passes through the intermediate shaft 22 and is used for transmitting power to the first wheel, and the second power output half shaft 31 is used for transmitting power to the second wheel.

[0045] According to another preferred embodiment of the present application, the first power output half shaft 36 is directly connected or connected through a first wheel edge reduction planetary gear set to the first wheel, and the second power output half shaft 31 is directly connected or connected through a second wheel edge reduction planetary gear set to the second wheel.

[0046] According to another preferred embodiment of the present application, referring to Figure 1 , the first parallel shaft 14 and the second parallel shaft 30 are distributed on both sides of the intermediate shaft 22.

[0047] According to another preferred embodiment of the present application, the differential 27, the second shift gear, the third shift driving gear 26, the first shift driven gear 18, the first shift gear and the second shift driven gear 19 are arranged in sequence in the direction in which the first power output half shaft 36 extends.

[0048] According to another preferred embodiment of the present application, the first shift gear and the second shift gear each comprise a gear hub and a shift element.

[0049] According to another preferred embodiment of the present application, referring to Figure 6 , the high-efficiency four-gear electric drive axle transmission system further comprises a second input unit 43, which has the same structure as the first input unit. That is, two motors are used to input power.

[0050] According to another preferred embodiment of the present application, referring to Figure 7 , the high-efficiency four-gear electric drive axle transmission system further comprises a second transmission unit 44, which has the same structure as the first transmission unit. That is, two sets of transmission units are used to transmit power, which can be arranged on both sides of the intermediate shaft.

[0051] According to another preferred embodiment of the present application, referring to Figure 9 The end of the second parallel shaft 30 is connected to the PTO device through a connection and disconnection mechanism.

[0052] According to another preferred embodiment of the present application, referring to Figure 8 A high-efficiency four-gear electric drive axle transmission system is also provided, characterized in that it comprises:

[0053] The first input unit comprises an input driving gear 13 driven by the first motor 11, a first parallel shaft 14 connected in sequence with an input driven gear 16, a first gear shifting driving gear 15, a first gear shifter, and a second gear shifting driving gear 17, the input driving gear 13 being used to transmit power to the first parallel shaft 14 via the input driven gear 16, and the first gear shifter being selectively coupled to the first gear shifting driving gear 15 or the second gear shifting driving gear 17 for transmitting power from the first parallel shaft 14 to the first gear shifting driving gear 15 or the second gear shifting driving gear 17.

[0054] The intermediate shaft 22 is fixedly connected with a second gear shifter, a first gear shifting driven gear 18, and a second gear shifting driven gear 19, and rotatably sleeved with a third gear shifting driving gear 26, the first gear shifting driving gear 15 being used to transmit power to the intermediate shaft 22 via the first gear shifting driven gear 18, and the second gear shifting driving gear being used to transmit power to the intermediate shaft 22 via the second gear shifting driven gear 19.

[0055] The first transmission unit comprises a second parallel shaft 30, and a third gear shifting driven gear 29 and a fourth gear shifting driving gear 28 fixedly connected to the second parallel shaft 30, the third gear shifting driving gear 26 being used to transmit power to the third gear shifting driven gear 29; and

[0056] The differential 27 is provided with a first power output half shaft 36 and a second power output half shaft 31, and the housing of the differential 27 is sleeved with a fourth gear shifting driven gear 25, the fourth gear shifting driving gear 28 being used to transmit power to the fourth gear shifting driven gear 25, and the second gear shifter being selectively coupled to the third gear shifting driving gear 26 or the fourth gear shifting driven gear 25 for transmitting power from the intermediate shaft 22 to the third gear shifting driving gear 26 or the fourth gear shifting driven gear 25.

[0057] The first power output half shaft 36 passes through the intermediate shaft 22 and is used to transmit power to the first wheel, and the second power output half shaft 31 is used to transmit power to the second wheel.

[0058] According to another preferred embodiment of the present application, the high-efficiency four-gear electric drive axle transmission system further comprises a second input unit and / or a second transmission unit, the second input unit having the same structure as the first input unit, and the second transmission unit having the same structure as the first transmission unit.

[0059] According to another preferred embodiment of the present application, a high-efficiency four-gear electric drive axle transmission system is provided, characterized in that an electric motor 11, an input shaft 12, and an input driving gear 13 are arranged on one side of the axle, one end of the input shaft 12 is connected to the electric motor 11, and one end of the input shaft 12 is connected to the input driving gear 13, wherein the input shaft 12 is connected to the rotor shaft of the electric motor 11 through a spline, and the input driving gear 13 is fixedly installed on the input shaft 12.

[0060] Preferably, a first parallel shaft 14, a first gear shifting driving gear 15, a second gear shifting driving gear 17, and an input driven gear 16 are arranged on one side of the axle, the first gear shifting driving gear 15, the second gear shifting driving gear 17, and the input driven gear 16 are all fixedly installed on the first parallel shaft 14, and the input driven gear 16 is engaged with the input driving gear 13.

[0061] Preferably, the components 11 to 17 can be arranged in one set as shown in the schematic diagram of the preferred embodiment, i.e., a single-motor power input scheme, or can be arranged in two sets as shown in Figure 1 : the embodiment case 2, i.e., a double-motor power input scheme. Figure 6

[0062] Preferably, an intermediate shaft 22 is arranged at the center of the axle, the first gear shifting driven gear 18, the second gear shifting driven gear 19, and the third gear shifting driving gear 26 are installed on the intermediate shaft 22 through bearing rings, the first gear shifting driven gear 18 is engaged with the first gear shifting driving gear 15, and the second gear shifting driven gear 19 is engaged with the second gear shifting driving gear 17. A first gear hub 21 and a second gear hub 23 are fixedly installed on the intermediate shaft 22, a first gear shifting element 20 is installed on the first gear hub 21 and can slide axially, and a second gear shifting element 24 is installed on the second gear hub 23 and can slide axially.

[0063] Preferably, a differential 27 is coaxially installed with the intermediate shaft 22, and a fourth gear shifting driven gear 25 is fixedly installed on the differential 27.

[0064] Preferably, a second parallel shaft 30 is installed in parallel with the first parallel shaft 14 and is distributed on both sides of the intermediate shaft 22, and the second parallel shaft 30 has a third gear shifting driven gear 29 and a fourth gear shifting driving gear 28 fixedly installed at both ends thereof, wherein the third gear shifting driven gear 29 is engaged with the third gear shifting driving gear 26, and the fourth gear shifting driving gear 28 is engaged with the fourth gear shifting driven gear 25. ​

[0065] Preferably, the second parallel shaft 30 and the third shift driven gear 29 and the fourth shift driving gear 28 mounted on the second parallel shaft 30 can be arranged as shown in the schematic diagram of the preferred embodiment transmission structure. Figure 1 Preferably, the second parallel shaft 30 and the third shift driven gear 29 and the fourth shift driving gear 28 mounted on the second parallel shaft 30 can be arranged as shown in the schematic diagram of the preferred embodiment transmission structure. Figure 7 Preferably, the second parallel shaft 30 and the third shift driven gear 29 and the fourth shift driving gear 28 mounted on the second parallel shaft 30 can be arranged as shown in the schematic diagram of the preferred embodiment transmission structure.

[0066] Preferably, the first shift driven gear 18 is mounted with a coupling tooth A, the second shift driven gear 19 is mounted with a coupling tooth B, the third shift driving gear 26 is mounted with a coupling tooth C, and the fourth shift driven gear 25 is mounted with a coupling tooth D. When the first shift element 20 moves to the left, the first shift element 20 will engage with the coupling tooth A, and the power from the motor will be transmitted to the intermediate shaft 22 through the first shift gear pair. When the first shift element 20 moves to the right, the first shift element 20 will engage with the coupling tooth B, and the power from the motor will be transmitted to the intermediate shaft 22 through the second shift gear pair. When the second shift element 24 moves to the right, the second shift element 24 will engage with the coupling tooth C, and the power from the intermediate shaft will be transmitted to the differential 27 through the third shift gear pair and the fourth shift gear pair. When the second shift element 24 moves to the left, the second shift element 24 will engage with the coupling tooth D, and the power from the intermediate shaft will be transmitted to the differential 27 directly through the second shift element 24, and the third shift gear pair and the fourth shift gear pair will be in idle state.

[0067] Preferably, the differential 27 is connected with the left half shaft 31 and the right half shaft 36 at both ends respectively.

[0068] Preferably, the left half shaft 31 is connected with the left wheel side, which can be an assembly without a reducer structure or an assembly with a reducer structure. The wheel side reducer is a planetary gear reducer, and the left sun gear 32 of the planetary gear reducer is connected with the left half shaft 31. The left sun gear 32 is circumferentially distributed with N (N is generally 4 or 5) left planet gears 34, which are installed on the left planet carrier 33 through bearings and simultaneously engage with the left sun gear 32 and the left ring gear 35 fixed on the axle housing. The power of the planetary gear is input from the left sun gear 32 and output to the left tire 41 from the left planet carrier 33.

[0069] Preferably, the right half axle 36 is connected to the right wheel rim, which can be a non-reducer assembly or a reducer assembly. The wheel rim reducer is a planetary reducer, the right half axle 36 is connected to the right sun gear 337 of the planetary reducer, the right sun gear 337 is circumferentially distributed with N (N is generally 4 or 5) right planet gears 39, the right planet gears 39 are mounted on the right planet carrier 38 through bearings, and the right planet gears 39 are in mesh with the right sun gear 337 and the right ring gear 40 fixed on the axle housing, the power of the planetary reducer is input by the right sun gear 337 and output by the right planet carrier 38 to the right tire 42.

[0070] Preferably, the power of the motor is transmitted to the left and right wheel rims, and the first shift element 20 and the second shift element 24 must be in working condition at the same time, that is, the two shifters must be in mesh with the engagement teeth, and the power of the motor can be output to the wheel end. As long as any one of the two shifters is in the neutral position, the power of the motor is disconnected. This design can ensure that the simultaneous engagement of the two shifters will not cause the risk of transmission system seizure.

[0071] Preferably, when the second shift element 24 moves to the left and is in mesh with the engagement teeth D on the fourth shift driven gear 25, the power transmission from the motor to the wheel rim only experiences a three-stage reduction structure, regardless of whether the first shift element 20 is in mesh with the engagement teeth A or the engagement teeth B at this time. The mechanical efficiency of the transmission system is relatively high at these two gears. When the second shift element 24 moves to the right and is in mesh with the engagement teeth C on the third shift driven gear 26, the power transmission from the motor to the wheel rim needs to experience a five-stage reduction structure, regardless of whether the first shift element 20 is in mesh with the engagement teeth A or the engagement teeth B at this time. The transmission system can provide a large enough reduction ratio to improve the output torque of the wheel rim at these two gears.

[0072] Preferably, the first shift element 20 can be installed on the first parallel shaft 14, as shown in Figure 8 : the embodiment 4, at this time, the first shift driven gear 15 and the second shift driven gear 17 are installed on the first parallel shaft 14 through bearing rings, the engagement teeth A are installed on the first shift driven gear 15, the engagement teeth B are installed on the second shift driven gear 17, and the first shift driven gear 18 and the second shift driven gear 19 are fixedly installed on the intermediate shaft 22.

[0073] Preferably, the end of the second parallel shaft can be connected to a PTO device, as shown in Figure 9 : the component 43 in the embodiment 5, the PTO has a connection and disconnection mechanism with the second parallel shaft. When the mechanism is connected, the PTO is connected to the second parallel shaft and is in working mode. When the mechanism is disconnected, the PTO is disconnected from the second parallel shaft and is in non-working mode.

[0074] The working principle of the first preferred scheme is described in detail as follows:

[0075] A block power flow: as shown in the figure, Figure 2 The motor torque 11 is transmitted to the input driving gear 13 through the input shaft 12, the input driving gear 13 and the input driven gear 16 are in constant engagement, the input driven gear 16 is fixedly installed on the first parallel shaft 14, and the torque on the input driving gear 13 is transmitted to the parallel shaft 14 through the input driven gear 16 engaged therewith. The first shift driving gear 15 and the second shift driving gear 17 are also fixedly installed on the parallel shaft 14, and the first shift driving gear 15 and the second shift driving gear 17 are engaged with the first shift driven gear 18 and the second shift driven gear 19 respectively, which are sleeved on the intermediate shaft 22. The intermediate shaft is also sleeved with the third shift driving gear 26 and the first shift element 20 and the second shift element 24 fixedly installed thereon. When the first shift element 20 slides to the left, the first shift element 20 is engaged with the engaging teeth A installed on the first shift driven gear 18. At this time, the power on the first parallel shaft 14 is transmitted to the intermediate shaft 22 through the first shift gear pair and the first shift element 20. The second parallel shaft 30 is arranged on the other side of the intermediate shaft 22, and the third shift driven gear 29 and the fourth shift driving gear 28 are fixedly installed on the second parallel shaft 30, wherein the third shift driven gear 29 is engaged with the third shift driving gear 26, and the fourth shift driving gear 28 is engaged with the fourth shift driven gear 25 fixedly installed on the differential 27. When the second shift element 24 slides to the right, the second shift element 24 is engaged with the engaging teeth C installed on the third shift driving gear, and the power on the intermediate shaft 22 is transmitted to the differential 27 through the second shift element 24, the third shift gear pair and the fourth shift gear pair. The power on the differential 27 is transmitted to the left half shaft 31 and the right half shaft 36 according to the actual road conditions of the vehicle, one end of the left half shaft 31 is connected with the left sun gear of the differential, and the other end is connected with the left sun gear 32 of the left wheel side planetary reducer. Since the gear ring 35 of the left wheel side planetary reducer is fixedly installed on the axle housing, the power on the left half shaft 31 is transmitted to the left planet carrier 33 through the left sun gear 32 and the left planet gear 34, and finally transmitted to the left tire 41. One end of the right half shaft 36 is connected with the right sun gear of the differential, and the other end is connected with the right sun gear 37 of the right wheel side planetary reducer. Since the gear ring 40 of the right wheel side planetary reducer is fixedly installed on the axle housing, the power on the right half shaft 36 is transmitted to the right planet carrier 38 through the right sun gear 37 and the right planet gear 39, and finally transmitted to the right tire 42.

[0076] B block power flow: as shown in the figure, Figure 3As shown, the motor torque 11 is transmitted to the input driving gear 13 through the input shaft 12, the input driving gear 13 and the input driven gear 16 are in constant engagement, the input driven gear 16 is fixedly installed on the first parallel shaft 14, thus the torque on the input driving gear 13 is transmitted to the parallel shaft 14 through the input driven gear 16 engaged with it. The first shift driving gear 15 and the second shift driving gear 17 are also fixedly installed on the parallel shaft 14, the first shift driving gear 15 and the second shift driving gear 17 are engaged with the first shift driven gear 18 and the second shift driven gear 19 respectively, which are sleeved on the intermediate shaft 22. The intermediate shaft is also sleeved with the third shift driving gear 26 and the first shift element 20 and the second shift element 24 fixedly installed thereon, when the first shift element 20 slides to the right, the first shift element 20 is engaged with the engaging teeth B installed on the second shift driven gear 19. At this time, the power on the first parallel shaft 14 is transmitted to the intermediate shaft 22 through the second shift gear pair and the first shift element 20. The second parallel shaft 30 is arranged on the other side of the intermediate shaft 22, the third shift driven gear 29 and the fourth shift driving gear 28 are fixedly installed on the second parallel shaft 30, the third shift driven gear 29 is engaged with the third shift driving gear 26, and the fourth shift driving gear 28 is engaged with the fourth shift driven gear 25 fixedly installed on the differential 27. When the second shift element 24 slides to the right, the second shift element 24 is engaged with the engaging teeth C installed on the third shift driving gear, the power on the intermediate shaft 22 is transmitted to the differential 27 through the second shift element 24, the third shift gear pair and the fourth shift gear pair. The power on the differential 27 is transmitted to the left half shaft 31 and the right half shaft 36 according to the actual road conditions of the vehicle, one end of the left half shaft 31 is connected with the left sun gear of the differential, and the other end is connected with the left sun gear 32 of the left wheel side planetary reducer, since the gear ring 35 of the left wheel side planetary reducer is fixedly installed on the axle housing, the power on the left half shaft 31 is transmitted to the left planet carrier 33 through the left sun gear 32 and the left planet gear 34, and finally transmitted to the left tire 41. One end of the right half shaft 36 is connected with the right sun gear of the differential, and the other end is connected with the right sun gear 37 of the right wheel side planetary reducer, since the gear ring 40 of the right wheel side planetary reducer is fixedly installed on the axle housing, the power on the right half shaft 36 is transmitted to the right planet carrier 38 through the right sun gear 37 and the right planet gear 39, and finally transmitted to the right tire 42.

[0077] C power flow: as Figure 4As shown, the motor torque 11 is transmitted to the input driving gear 13 through the input shaft 12, the input driving gear 13 and the input driven gear 16 are in constant engagement, the input driven gear 16 is fixedly installed on the first parallel shaft 14, thus the torque on the input driving gear 13 is transmitted to the parallel shaft 14 through the input driven gear 16 engaged therewith. The first shift driving gear 15 and the second shift driving gear 17 are also fixedly installed on the parallel shaft 14, the first shift driving gear 15 and the second shift driving gear 17 are engaged with the first shift driven gear 18 and the second shift driven gear 19 respectively which are sleeved on the intermediate shaft 22. The third shift driving gear 26 and the first shift element 20 and the second shift element 24 fixedly installed on the intermediate shaft 22, when the first shift element 20 slides to the left, the first shift element 20 is engaged with the engaging tooth A installed on the first shift driven gear 18. At this time, the power on the first parallel shaft 14 is transmitted to the intermediate shaft 22 through the first shift gear pair and the first shift element 20. The second parallel shaft 30 is arranged on the other side of the intermediate shaft 22, the third shift driven gear 29 and the fourth shift driving gear 28 are fixedly installed on the second parallel shaft 30, the third shift driven gear 29 is engaged with the third shift driving gear 26, the fourth shift driving gear 28 is engaged with the fourth shift driven gear 25 fixedly installed on the differential 27. When the second shift element 24 slides to the left, the second shift element 24 is engaged with the engaging tooth D installed on the fourth shift driven gear, the power on the intermediate shaft 22 is directly transmitted to the differential 27 through the second shift element 24. The power on the differential 27 is transmitted to the left half shaft 31 and the right half shaft 36 according to the actual road conditions of the vehicle, one end of the left half shaft 31 is connected with the left sun gear of the differential, and the other end is connected with the left sun gear 32 of the left wheel side planetary reducer, since the gear ring 35 of the left wheel side planetary reducer is fixedly installed on the axle housing, the power on the left half shaft 31 is transmitted to the left planet carrier 33 through the left sun gear 32 and the left planet gear 34, and finally transmitted to the left tire 41. One end of the right half shaft 36 is connected with the right sun gear of the differential, and the other end is connected with the right sun gear 37 of the right wheel side planetary reducer, since the gear ring 40 of the right wheel side planetary reducer is fixedly installed on the axle housing, the power on the right half shaft 36 is transmitted to the right planet carrier 38 through the right sun gear 37 and the right planet gear 39, and finally transmitted to the right tire 42.

[0078] D power flow: as Figure 5As shown, the motor torque 11 is transmitted to the input driving gear 13 through the input shaft 12, the input driving gear 13 and the input driven gear 16 are in constant engagement, the input driven gear 16 is fixedly installed on the first parallel shaft 14, and thus the torque on the input driving gear 13 is transmitted to the parallel shaft 14 through the input driven gear 16 engaged therewith. The first shift driving gear 15 and the second shift driving gear 17 are also fixedly installed on the parallel shaft 14, and the first shift driving gear 15 and the second shift driving gear 17 are engaged with the first shift driven gear 18 and the second shift driven gear 19 respectively which are sleeved on the intermediate shaft 22. The intermediate shaft is also sleeved with the third shift driving gear 26 and the first shift element 20 and the second shift element 24 which are fixedly installed thereon. When the first shift element 20 slides to the right, the first shift element 20 is engaged with the engaging teeth B installed on the second shift driven gear 19. At this time, the power on the first parallel shaft 14 is transmitted to the intermediate shaft 22 through the second shift gear pair and the first shift element 20. The second parallel shaft 30 is arranged on the other side of the intermediate shaft 22, and the third shift driven gear 29 and the fourth shift driving gear 28 are fixedly installed on the second parallel shaft 30, wherein the third shift driven gear 29 is engaged with the third shift driving gear 26, and the fourth shift driving gear 28 is engaged with the fourth shift driven gear 25 fixedly installed on the differential 27. When the second shift element 24 slides to the left, the second shift element 24 is engaged with the engaging teeth D installed on the fourth shift driven gear, and the power on the intermediate shaft 22 is directly transmitted to the differential 27 through the second shift element 24. The power on the differential 27 is transmitted to the left half shaft 31 and the right half shaft 36 according to the actual road conditions of the vehicle, one end of the left half shaft 31 is connected with the left sun gear of the differential, and the other end is connected with the left sun gear 32 of the left wheel side planetary reducer. Since the gear ring 35 of the left wheel side planetary reducer is fixedly installed on the axle housing, the power on the left half shaft 31 is transmitted to the left planet carrier 33 through the left sun gear 32 and the left planet gear 34, and finally transmitted to the left tire 41. One end of the right half shaft 36 is connected with the right sun gear of the differential, and the other end is connected with the right sun gear 37 of the right wheel side planetary reducer. Since the gear ring 40 of the right wheel side planetary reducer is fixedly installed on the axle housing, the power on the right half shaft 36 is transmitted to the right planet carrier 38 through the right sun gear 37 and the right planet gear 39, and finally transmitted to the right tire 42.

[0079] The present application can achieve one or more of the following technical effects:

[0080] 1. Four-axle arrangement, which can adjust the axial distance between the first and second axles and the second and third axles respectively, can more reasonably design gear parameters, and the first parallel shaft and the second parallel shaft are distributed on both sides of the intermediate shaft, so that the electric drive axle structure tends to be symmetrical and does not produce too much bias.

[0081] 2、Adopt double shift structure, can realize four gear functions, low gear matches a big transmission ratio, provides a big enough torque for vehicle in starting, getting out of trouble, climbing and other conditions, high gear matches a small transmission ratio, provides a high enough speed for vehicle in high speed, empty car and other conditions, the middle two gears match two high efficiency transmission ratios between low gear and high gear according to vehicle common conditions, provides a higher torque and higher speed power demand for vehicle in non-extreme conditions. The shift ratio between four gears will be greatly reduced compared with two gears, which can reduce shift impact, provide vehicle comfort, and also improve motor efficiency and increase vehicle range.

[0082] 3、When the second shift moves to the left and engages with the engagement teeth on the fourth shift passive gear, no matter whether the first shift engages with the engagement teeth A on the second shift passive gear or with the engagement teeth B on the first shift passive gear, the power on the motor is transmitted to the intermediate shaft, and then the power of the intermediate shaft is directly transmitted to the differential through the second shift, without passing through the third and fourth shift gear pairs, which can reduce two-stage transmission and improve mechanical transmission efficiency.

[0083] 4、The intermediate gearbox is all cylindrical fixed shaft gears, which places the planetary row on the wheel edge, reducing the difficulty of gearbox structure design, processing and assembly.

[0084] Those skilled in the art should understand that the present application is not limited to the above embodiments, and the above embodiments and descriptions in the specification are only to illustrate the principles of the present application, and various changes and improvements can be made without departing from the spirit and scope of the present application, and these changes and improvements all fall within the scope of the claimed present application. The scope of protection of the present application is defined by the appended claims and their equivalents.

Claims

1. A high efficiency four-gear electric drive axle transmission system, characterized in that The first input unit comprises: an input driving gear driven by the first motor; and a first parallel shaft fixedly connected with a second shift driving gear, an input driven gear and the first shift driving gear in sequence, the input driving gear being configured to transmit power to the input driven gear. The intermediate shaft is fixedly connected with the first shift device and the second shift device and is rotatably sleeved with the first shift driven gear, the second shift driven gear and the third shift driving gear in sequence, the second shift driving gear being configured to transmit power to the second shift driven gear, the first shift driving gear being configured to transmit power to the first shift driven gear, the first shift device being configured to selectively combine with the second shift driven gear or the first shift driven gear to transmit power from the second shift driven gear or the first shift driven gear to the intermediate shaft. The first transmission unit comprises a second parallel shaft and a third shift driven gear and a fourth shift driving gear fixedly connected to the second parallel shaft, the third shift driving gear being configured to transmit power to the third shift driven gear. The differential is provided with a first power output half shaft and a second power output half shaft, and the differential housing is sleeved with a fourth shift driven gear, the fourth shift driving gear being configured to transmit power to the fourth shift driven gear, the second shift device being configured to selectively combine with the third shift driving gear or the fourth shift driven gear to transmit power from the intermediate shaft to the third shift driving gear or the fourth shift driven gear. The first power output half shaft passes through the intermediate shaft and is configured to transmit power to the first wheel, and the second power output half shaft is configured to transmit power to the second wheel. The first power output half shaft is directly connected to the first wheel or is connected to the first wheel via a first wheel edge reduction planetary gear train, and the second power output half shaft is directly connected to the second wheel or is connected to the second wheel via a second wheel edge reduction planetary gear train.

2. The high efficiency four-speed electric drive axle transmission system of claim 1, wherein The first parallel shaft and the second parallel shaft are distributed on both sides of the intermediate shaft.

3. The high efficiency four-speed electric drive axle transmission system of claim 2, wherein The differential, the second shift device, the third shift driving gear, the first shift driven gear, the first shift device and the second shift driven gear are arranged in sequence in the direction in which the first power output half shaft extends.

4. The high efficiency four-speed electric drive axle transmission system of any one of claims 1-3, wherein The first shift device and the second shift device each comprise a gear hub and a shift element.

5. The high efficiency four-speed electric drive axle transmission system of claim 4, wherein The second input unit has the same structure as the first input unit.

6. The high efficiency four-speed electric drive axle transmission system of claim 4, wherein The second transmission unit has the same structure as the first transmission unit.

7. The high efficiency four-speed electric drive axle transmission system of claim 6, wherein The end of the second parallel shaft is connected to a PTO device via a connection and disconnection mechanism.

8. The high efficiency four-speed electric drive axle transmission system of claim 7, wherein The first input unit comprises: an input driving gear driven by the first motor; and a first parallel shaft fixedly connected with a second shift driving gear, an input driven gear, a first shift device and a second shift driving gear in sequence, the input driving gear being configured to transmit power to the first parallel shaft via the input driven gear, the first shift device being configured to selectively combine with the first shift driving gear or the second shift driving gear to transmit power from the first parallel shaft to the first shift driving gear or the second shift driving gear.

9. A high efficiency four-gear electric drive axle transmission system, characterized in that ​ ​ The intermediate shaft is fixedly connected with the second shift device, the first shift driven gear and the second shift driven gear, and is sleeved with the third shift driving gear in a rotatable manner, the first shift driving gear is used for transmitting power to the intermediate shaft via the first shift driven gear, and the second shift driving gear is used for transmitting power to the intermediate shaft via the second shift driven gear; The first transmission unit comprises a second parallel shaft, and the third shift driven gear and the fourth shift driving gear fixedly connected to the second parallel shaft, and the third shift driving gear is used for transmitting power to the third shift driven gear; and The differential is provided with the first power output half shaft and the second power output half shaft, and the housing of the differential is sleeved with the fourth shift driven gear in the outer periphery, the fourth shift driving gear is used for transmitting power to the fourth shift driven gear, and the second shift device is selectively combined to the third shift driving gear or the fourth shift driven gear for transmitting power from the intermediate shaft to the third shift driving gear or the fourth shift driven gear; The first power output half shaft passes through the intermediate shaft and is used for transmitting power to the first wheel, and the second power output half shaft is used for transmitting power to the second wheel.

10. The high efficiency four-speed electric drive axle transmission system of claim 9, wherein The second input unit has the same structure as the first input unit, and the second transmission unit has the same structure as the first transmission unit.

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