Multi-gear electric drive axle system, combined structure and vehicle

Abstract

The invention provides a multi-gear electric drive axle system, a combined structure and a vehicle. The multi-gear electric drive axle system comprises a motor, a differential mechanism, an output shaft, a first intermediate shaft, a second intermediate shaft and a third intermediate shaft. The motor inputs power through the first intermediate shaft, the third intermediate shaft and the second intermediate shaft in sequence, and the third intermediate shaft is hollowly sleeved on the output shaft; a first gear set and a first gear shifting mechanism are arranged on the third intermediate shaft; a second gear set, a second gear shifting mechanism and a third transmission gear are arranged on the second intermediate shaft, and the third transmission gear is meshed with the differential mechanism; gears in the first gear set are kept in a constant meshing state with corresponding gears in the second gear set to form a plurality of transmission gear pairs, and the transmission gear pairs have different transmission ratios; through different combination states of the first gear shifting mechanism, the second gear shifting mechanism and the corresponding gear sets, power transmission of multiple different gears can be achieved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of electric drive axle, and particularly relates to a multi-gear electric drive axle system, a combined structure and a vehicle. BACKGROUND

[0002] At present, heavy commercial trucks driven by pure electricity mainly adopt two driving modes of central electric drive and electric drive axle to realize power transmission of the vehicle. The electric drive axle shows greater development potential due to its smaller installation space. The internal transmission structure of the electric drive axle is mostly parallel gear, planetary gear or a mixed arrangement of the two. The full-parallel gear structure of the single-motor electric drive axle has been widely applied, and usually adopts one driving motor and is mostly arranged in three gears.

[0003] In the prior art, a common electric drive axle structure usually realizes three gears through arrangement of multiple parallel shafts, and one of the gears is a direct gear (the differential shaft and the main shaft are directly connected through a shift sleeve). However, when the three-gear arrangement simultaneously considers large torque at low speed and high efficiency at high speed, the speed ratio difference is large, which affects the smoothness of gear shifting and power performance. In addition, the structural arrangement of the direct gear is relatively complex, and the front bearing of the differential needs to be enlarged, and the rear bearing of the main shaft needs to be arranged with the differential housing as the bearing outer ring seat, so as to leave space for arranging the gear shifting sleeve.

[0004] For heavy commercial trucks, both large torque at low speed to cope with starting and climbing conditions and high efficiency at high speed to reduce energy consumption are needed. The existing three-gear electric drive system is difficult to meet both requirements while ensuring smooth gear shifting, especially when the speed ratio difference is large, which often leads to obvious gear shifting impact or power interruption. In addition, the structural arrangement of the three-gear system often leads to complex design of the gear shifting mechanism, increasing the manufacturing difficulty and cost. SUMMARY

[0005] The present application discloses a multi-gear electric drive axle system, a combined structure and a vehicle, and aims to solve the technical problems existing in the prior art.

[0006] The present application adopts the following technical scheme:

[0007] In a first aspect, the present application provides a multi-gear electric drive axle system, which comprises a motor, a differential, an output shaft and first, second and third intermediate shafts arranged in parallel.

[0008] The motor sequentially inputs power to the system through the first, third and second intermediate shafts, and the third intermediate shaft is sleeved on the output shaft.

[0009] The third intermediate shaft is provided with a first gear set and a first gear shifting mechanism, and the first gear shifting mechanism is selectively connected in transmission with different transmission ratio gears in the first gear set.

[0010] The second intermediate shaft is provided with a second gear set, a second shift mechanism and a third transmission gear, the second shift mechanism is selectively in transmission connection with different transmission ratio gears in the second gear set, and the third transmission gear is in mesh with the differential;

[0011] The gears in the first gear set and the corresponding gears in the second gear set are in constant meshing state, forming multiple sets of transmission gear pairs, each set of transmission gear pair having different transmission ratio; different combination states of the first shift mechanism and the second shift mechanism are used to realize power transmission of multiple different gears.

[0012] As a preferred technical solution, an input shaft is further included, the input shaft is in transmission connection with the motor and is arranged in parallel with the first intermediate shaft;

[0013] The first intermediate shaft is provided with a third gear set, the third gear set includes a first transmission gear and a second transmission gear, the first transmission gear is in mesh with the input shaft, and the second transmission gear is in transmission connection with the third intermediate shaft, for transmitting power of the motor to the third intermediate shaft.

[0014] As a preferred technical solution, the first gear set includes a three-gear driving gear and a four-gear driving gear, the three-gear driving gear and the four-gear driving gear are sleeved on the third intermediate shaft, and the first shift mechanism is selectively in transmission connection with the three-gear driving gear, the four-gear driving gear or neither of them.

[0015] As a preferred technical solution, the second intermediate shaft is provided with a three-gear driven gear and a four-gear driven gear, the three-gear driven gear is in mesh with the three-gear driving gear, and the four-gear driven gear is in mesh with the four-gear driving gear.

[0016] As a preferred technical solution, the second gear set includes a one-gear driven gear and a two-gear driven gear, the one-gear driven gear and the two-gear driven gear are sleeved on the second intermediate shaft, and the second shift mechanism is selectively in transmission connection with the one-gear driven gear, the two-gear driven gear or neither of them.

[0017] As a preferred technical solution, the third intermediate shaft is provided with a one-gear driving gear and a two-gear driving gear, the one-gear driving gear is in mesh with the one-gear driven gear, and the two-gear driving gear is in mesh with the two-gear driven gear.

[0018] As a preferred technical solution, the one-gear driving gear, the two-gear driving gear, the three-gear driving gear and the four-gear driving gear are arranged in sequence along the axial direction of the third intermediate shaft; and the one-gear driven gear, the two-gear driven gear, the three-gear driven gear and the four-gear driven gear are arranged in sequence along the axial direction of the second intermediate shaft.

[0019] As a preferred technical solution, the first drive gear and the first driven gear have a first transmission ratio, the second drive gear and the second driven gear have a second transmission ratio, the third drive gear and the third driven gear have a third transmission ratio, and the fourth drive gear and the fourth driven gear have a fourth transmission ratio.

[0020] The first transmission ratio to the fourth transmission ratio decreases in turn.

[0021] As a preferred technical solution, the first shift mechanism includes a first shift actuator and a first shift sleeve, and the first shift actuator is configured to drive the first shift sleeve to move axially on the third intermediate shaft to selectively connect in transmission with the third drive gear or the fourth drive gear.

[0022] The second shift mechanism includes a second shift actuator and a second shift sleeve, and the second shift actuator is configured to drive the second shift sleeve to move axially on the second intermediate shaft to selectively connect in transmission with the first driven gear or the second driven gear.

[0023] In a second aspect, the embodiments of the present application further provide a multi-gear electric drive axle system combination structure, which includes two symmetrically arranged multi-gear electric drive axle systems according to any one of the above, and an inter-axle differential lock mechanism arranged between the two multi-gear electric drive axle systems.

[0024] The driven bevel gear is arranged on the bevel gear transmission shaft, the bevel gear transmission shaft is in transmission connection with a gear of the second intermediate shaft, and the interlocking sleeve can selectively mesh with the driven bevel gear.

[0025] As a preferred technical solution, the interlocking transmission shaft is arranged in the power transmission path of the multi-gear electric drive axle system close to the motor and / or away from the differential.

[0026] As a preferred technical solution, when both interlocking sleeves mesh with the corresponding driven bevel gears, the two multi-gear electric drive axle systems are interlocked; when both interlocking sleeves do not mesh with the corresponding driven bevel gears, the two multi-gear electric drive axle systems can be differentially locked, and the interlocking transmission shaft does not idle.

[0027] In a third aspect, the embodiments of the present application provide a vehicle including the multi-gear electric drive axle system according to any one of the above or the multi-gear electric drive axle system combination structure according to any one of the above.

[0028] One embodiment of the above-mentioned application has the following advantages or beneficial effects:

[0029] The application provides a multi-gear electric drive axle system, which realizes power transmission of four gears through arrangement of three parallel shafts and two sets of gear shifting mechanisms, and can more finely match the requirements of vehicles in different working conditions. The four-gear structure can meet the requirements of large torque in low gears and high-speed driving in high gears while ensuring a small speed ratio difference, so that the motor always works in the best efficiency speed range, and the power performance and economy of the vehicle are improved.

[0030] Further, in the electric drive axle system provided by the application, the speed ratio gears of each gear are not associated with each other, and the speed ratio of each gear can be configured individually, so that modification and adjustment can be conveniently made according to the requirements of different vehicle models. The combination of the first gear shifting mechanism and the second gear shifting mechanism improves the flexibility of gear shifting, and the gears can be flexibly switched according to the driving state of the vehicle, so that smooth gear shifting is realized, and gear shifting impact and power interruption are reduced.

[0031] For the multi-gear electric drive axle system combination structure provided by the application, the inter-axle differential lock mechanism is arranged at the front end of the power transmission path, so that the interlocking transmission shaft can work in a high-speed low-torque state, and therefore the interlocking transmission shaft can be designed to be lighter and thinner, the rotational inertia and weight are greatly reduced, and the gear shifting response speed is improved. Meanwhile, by arranging two interlocking sleeves, it can be ensured that the interlocking transmission shaft will not idle in the non-interlocking state, so that energy loss is avoided and the system efficiency is improved. Compared with the traditional scheme of arranging an interlocking device near the differential, this structure not only reduces the weight of the vehicle, but also improves the reliability and maneuverability of the system, and provides a more efficient and reliable multi-axle drive solution for heavy commercial vehicles. BRIEF DESCRIPTION OF DRAWINGS

[0032] In order to more clearly illustrate the technical solutions of the embodiments of the application, the drawings needed in the embodiment description will be briefly introduced as follows, which form a part of the application. The schematic embodiments of the application and the description and explanation thereof do not constitute an improper limitation on the application. In the drawings:

[0033] Figure 1 a structural schematic diagram of the multi-gear electric drive axle system provided in a preferred embodiment of the application;

[0034] Figure 2 a power flow schematic diagram of the multi-gear electric drive axle system provided in a preferred embodiment of the application in a one-gear driving state;

[0035] Figure 3 a power flow schematic diagram of the multi-gear electric drive axle system provided in a preferred embodiment of the application in a two-gear driving state;

[0036] Figure 4A power flow schematic diagram of the multi-gear electric drive axle system provided in a preferred embodiment of the present application in a three-gear transmission state;

[0037] Figure 5 A power flow schematic diagram of the multi-gear electric drive axle system provided in a preferred embodiment of the present application in a four-gear transmission state;

[0038] Figure 6 A schematic diagram of the combined structure of the multi-gear electric drive axle system provided in a preferred embodiment of the present application.

[0039] Legend of reference signs:

[0040] Motor 11, input shaft 12, first intermediate shaft 21, first transmission gear 22, second transmission gear 23, second intermediate shaft 31, first-gear driven gear 32, second-gear driven gear 33, third-gear driven gear 34, fourth-gear driven gear 35, second-gear shift sleeve 36, second-gear shift actuator 37, third transmission gear 38, third intermediate shaft 41, first-gear driving gear 42, second-gear driving gear 43, third-gear driving gear 44, fourth-gear driving gear 45, first-gear shift sleeve 46, first-gear shift actuator 47, differential 51, output shaft 61, wheel end 71, interlocking transmission shaft 81, driven bevel gear 82, driving bevel gear 83, bevel gear transmission shaft 84, interlocking sleeve 85. DETAILED DESCRIPTION

[0041] In order to make the objects, technical solutions and advantages of the present application clearer, the technical solutions of the present application will be described below in conjunction with specific embodiments of the present application and corresponding drawings. In the description of the present application, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the context clearly indicates otherwise.

[0042] In the description of the present application, the terms "first", "second", etc. are only used for differentiation in description, and cannot be understood as indicating or implying relative importance. In the embodiments, the "system" is the "electric drive cooling system".

[0043] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without making creative efforts fall within the scope of protection of the present application.

[0044] To solve the problems in the prior art, the embodiments of the present application provide a multi-gear electric drive axle system, as Figure 1The electric drive axle system comprises a motor 11, a first intermediate shaft 21, a second intermediate shaft 31, a third intermediate shaft 41, a first gear set, a first shift mechanism, a second gear set, a second shift mechanism, a differential 51 and an output shaft 61; the first intermediate shaft 21, the second intermediate shaft 31 and the third intermediate shaft 41 are arranged in parallel, the motor 11 is in transmission connection with the third intermediate shaft 41 through the first intermediate shaft 21, the third intermediate shaft 41 is sleeved on the output shaft 61 and is not directly connected in transmission with the differential 51; the second intermediate shaft 31 is preferably arranged at the opposite side of the motor 11 and is not coaxially arranged with the differential 51; the first gear set and the first shift mechanism are arranged on the third intermediate shaft 41, the first shift mechanism is selectively in transmission connection with different gear ratios in the first gear set; the second gear set and the second shift mechanism are arranged on the second intermediate shaft 31, the second shift mechanism is selectively in transmission connection with different gear ratios in the second gear set; the third transmission gear 38 meshing with the differential 51 is further arranged on the second intermediate shaft 31, the power of the motor 11 input system is sequentially input to the differential 51 through the first intermediate shaft 21, the third intermediate shaft 41 and the second intermediate shaft 31 and is finally output to the output shaft 61 and the wheel end 71; through different combination states of the first shift mechanism and the second shift mechanism, power transmission of multiple different gears can be realized.

[0045] Specifically, the second intermediate shaft 31 is not coaxially arranged with the differential 51, which avoids the complex structure of the differential 51 and the second intermediate shaft 31 sharing a bearing, simplifies the manufacturing process and assembly process, and enables the second intermediate shaft 31 to be independently optimized in axial position and radial size, facilitating reasonable arrangement of gears and shift mechanisms of each gear.

[0046] In an alternative embodiment, a third shift mechanism can be further arranged between the third intermediate shaft 41 and the differential 51, which selectively realizes direct transmission connection between the third intermediate shaft 41 and the differential 51, thereby forming a fifth gear, i.e., a direct gear.

[0047] Specifically, when the system needs to switch to the fifth gear, the first shift mechanism and the second shift mechanism are both in the neutral state, i.e., neither of them establishes transmission connection with any gear in the corresponding gear set, while the third shift mechanism establishes transmission connection between the third intermediate shaft 41 and the differential 51. In this working mode, the power of the motor 11 is transmitted to the third intermediate shaft 41 through the first intermediate shaft 21, and then directly transmitted to the differential 51 through the third shift mechanism and finally output to the wheel end 71, forming a direct power transmission path. In this gear, transmission loss of intermediate links can be avoided, and transmission efficiency of the system in high-speed cruising conditions can be significantly improved.

[0048] By setting the fifth gear position, the multi-gear electric drive axle system provided by the embodiment further expands the applicable working condition range, is particularly suitable for the scene of long-time high-speed driving of the vehicle, effectively reduces energy consumption, and prolongs the cruising range. In addition, the implementation of the five-gear layout only needs to increase one gear shifting mechanism, the structure design is compact and reasonable, the manufacturing and assembly complexity is limited, and it has good engineering implementation value.

[0049] In a preferred embodiment, the motor shaft of the motor 11 is also drivingly connected with an input shaft 12, the input shaft 12 is arranged in parallel with the first intermediate shaft 21, the first intermediate shaft 21 is provided with a third gear set, the third gear set includes a first transmission gear 22 and a second transmission gear 23, the first transmission gear 22 is engaged with the input shaft 12, the second transmission gear is drivingly connected with the third intermediate shaft 41, and is used to transmit power of the motor 11 to the third intermediate shaft 41.

[0050] Specifically, the motor shaft of the motor 11 is drivingly and fixedly connected with the input shaft 12 through spline connection or the like. It should be noted that the "input shaft" in the embodiment refers to a transmission shaft that inputs power and driving force to the entire electric drive axle system, and the input shaft 12 is provided with a toothed portion, which realizes reliable power transmission through spline connection with the first transmission gear 22.

[0051] In a preferred embodiment, the driving connection between the second transmission gear 23 and the third intermediate shaft 41 is realized through a transmission gear arranged on the third intermediate shaft 41. Specifically, the third intermediate shaft 41 is drivingly and fixedly connected with a transmission gear engaged with the second transmission gear 23, and the two form a gear pair to realize stable power transmission. Preferably, the engagement between the first transmission gear 22 and the toothed portion of the input shaft 12, and the engagement between the second transmission gear 23 and the transmission gear on the third intermediate shaft 41, are both constant engagement structures, that is, these gears always remain in engagement state during the entire working process of the system, and do not need to be switched between engagement and disengagement.

[0052] By setting the constant engagement of the first transmission gear 22 and the second transmission gear 23, the continuity and stability of power transmission can be ensured, and the power interruption phenomenon that may occur during gear shifting can be avoided; at the same time, by reasonably selecting the gear ratio of the first transmission gear 22 and the second transmission gear 23, the basic matching between the motor 11 rotating speed and the transmission system can be realized, which lays a foundation for the speed ratio design of subsequent gears.

[0053] In a preferred embodiment, the first gear set includes a third-gear driving gear 44 and a fourth-gear driving gear 45, both of which are mounted on the third intermediate shaft 41 in a loose fit, and the first shift mechanism is selectively connected with the third-gear driving gear 44, the fourth-gear driving gear 45, or neither of them. Preferably, the second intermediate shaft 31 is provided with a third-gear driven gear 34 and a fourth-gear driven gear 35, which are fixedly connected with the second intermediate shaft 31, the third-gear driven gear 34 is in engagement with the third-gear driving gear 44, and the two gears have a third transmission ratio; the fourth-gear driven gear 35 is in engagement with the fourth-gear driving gear 45, and the two gears have a fourth transmission ratio.

[0054] Preferably, the first shift mechanism includes a first shift actuator 47 and a first shift sleeve 46, the first shift actuator 47 is used to drive the first shift sleeve 46 to move axially on the third intermediate shaft 41, so as to be selectively connected with the third-gear driving gear 44 or the fourth-gear driving gear 45.

[0055] Specifically, the first shift sleeve 46 is in sliding connection with the outer spline of the third intermediate shaft 41 through the inner spline, which can ensure that the first shift sleeve 46 moves axially while keeping synchronous rotation with the third intermediate shaft 41; the outer periphery of the first shift sleeve 46 is provided with an outer spline or a toothed structure which can be engaged with the toothed structure inside the third-gear driving gear 44 or the fourth-gear driving gear 45.

[0056] In the working state, when the first shift sleeve 46 is connected with the third-gear driving gear 44, the outer spline of the first shift sleeve 46 is engaged with the toothed structure inside the third-gear driving gear 44, so that the third-gear driving gear 44 rotates synchronously with the third intermediate shaft 41, at this time, the power of the system is transmitted to the third-gear driven gear 34 through the third-gear driving gear 44, and finally transmitted to the differential 51 through the second intermediate shaft 31, forming a third-gear transmission path; when the first shift sleeve 46 is connected with the fourth-gear driving gear 45, the power is transmitted through the fourth-gear driving gear 45 and the fourth-gear driven gear 35, forming a fourth-gear transmission path. When the first shift sleeve 46 is in the intermediate position and is not connected with the third-gear driving gear 44 and the fourth-gear driving gear 45, the power of the third intermediate shaft 41 will not be transmitted to the two driving gears.

[0057] Specifically, the "transmission ratio" in the embodiment refers to the speed ratio between gear pairs, that is, the tooth number ratio between the driving gear and the driven gear, which determines the relationship between the input speed and the output speed. Among them, the third transmission ratio refers to the tooth number ratio of the third-gear driving gear 44 to the third-gear driven gear 34, and the fourth transmission ratio refers to the tooth number ratio of the fourth-gear driving gear 45 to the fourth-gear driven gear 35.

[0058] It should be noted that the third transmission ratio and the fourth transmission ratio are not specifically limited in the embodiment, and the skilled in the art can select and adjust the transmission ratios of the gears according to the specific application requirements, such as the type of vehicle, the load characteristics, the working conditions, and the like, to obtain the optimal power performance and economic performance.

[0059] In a preferred embodiment, the second gear set includes a first driven gear 32 and a second driven gear 33, the first driven gear 32 and the second driven gear 33 are sleeved on the second intermediate shaft 31, and the second shift mechanism is selectively connected in transmission with the first driven gear 32, the second driven gear 33, or neither of them. Preferably, the third intermediate shaft 41 is fixedly connected with a first driving gear 42 and a second driving gear 43, the first driving gear 42 is engaged with the first driven gear 32, and the two gears have a first transmission ratio; the second driving gear 43 is engaged with the second driven gear 33, and the two gears have a second transmission ratio.

[0060] It should be noted that the first driving gear 42 and the second driving gear 43 are connected with the third intermediate shaft 41 in a fixed transmission manner, which ensures that they always rotate synchronously with the third intermediate shaft 41. This structure is complementary to the sleeve design of the third driving gear 44 and the fourth driving gear 45, and together forms a more flexible transmission path in the embodiment.

[0061] Preferably, the second shift mechanism includes a second shift actuator 37 and a second shift sleeve 36, the second shift actuator 37 is used to drive the second shift sleeve 36 to move axially on the second intermediate shaft 31, so as to be selectively connected in transmission with the first driven gear 32 or the second driven gear 33.

[0062] Specifically, the second shift sleeve 36 is connected with the outer spline of the second intermediate shaft 31 in sliding through the inner spline, so that the second shift sleeve 36 can move freely in the axial direction while keeping synchronous rotation with the second intermediate shaft 31; the outer periphery of the second shift sleeve 36 is provided with an outer spline or a toothed structure which can be engaged with the toothed structure inside the first driven gear 32 and the second driven gear 33.

[0063] In the working state, when the second shift sleeve 36 is in transmission connection with the first driven gear 32, the external spline of the second shift sleeve 36 is in mesh with the toothed structure on the inner side of the first driven gear 32, so that the first driven gear 32 is in rigid connection with the second intermediate shaft 31, and the rotation of the first driven gear 32 is directly transmitted to the second intermediate shaft 31. At this time, the power of the system is transmitted to the first driven gear 32 through the first driving gear 42, and finally transmitted to the differential 51 through the second intermediate shaft 31, forming a first gear transmission path. When the second shift sleeve 36 is in transmission connection with the second driven gear 33, the power is transmitted through the second driving gear 43 and the second driven gear 33, forming a second gear transmission path. When the second shift sleeve 36 is in the intermediate position and is not connected with the first driven gear 32 and the second driven gear 33, the third intermediate shaft 41 will not further transmit power to the second intermediate shaft 31 through the first driving gear 42 or the second driving gear 43.

[0064] Specifically, the first transmission ratio, the second transmission ratio, and the third transmission ratio and the fourth transmission ratio together constitute the complete transmission ratio sequence of the multi-gear electric drive axle system in the embodiment, which affects the output speed and torque characteristics of each gear position and has a decisive influence on the starting performance, climbing ability, and high-speed cruising efficiency of the vehicle.

[0065] In a preferred embodiment, the first transmission ratio, the second transmission ratio, the third transmission ratio, and the fourth transmission ratio are all different, and the ratio between adjacent transmission ratios is close, forming a geometric progression or an approximate geometric progression of transmission ratios, so as to ensure the smoothness of the shifting process, reduce the shifting impact, and improve the driving comfort.

[0066] When the vehicle switches gears, the change range of the motor 11 speed is directly related to the change range of the transmission ratio. The reasonable ratio between adjacent transmission ratios makes the motor 11 speed change relatively gently before and after shifting, avoiding sharp speed fluctuations and torque fluctuations. At the same time, the reasonable distribution of the transmission ratio also ensures that the motor 11 can work in a high-efficiency interval in each gear position, improves the energy utilization efficiency of the vehicle, and prolongs the cruising range.

[0067] It should be noted that although the embodiment does not give specific transmission ratio values, those skilled in the art can determine the most suitable transmission ratio configuration to obtain the best power performance and economic performance by combining theoretical calculation and actual testing according to the vehicle characteristics, load conditions, and use conditions.

[0068] In a preferred embodiment, the first drive gear 42, the second drive gear 43, the third drive gear 44 and the fourth drive gear 45 are arranged in sequence along the axial direction of the third intermediate shaft 41; the first driven gear 32, the second driven gear 33, the third driven gear 34 and the fourth driven gear 35 are arranged in sequence along the axial direction of the second intermediate shaft 31; and the first transmission ratio to the fourth transmission ratio decreases in sequence.

[0069] In this layout, the gear ratios of each gear are independent of each other, and there is no mechanical connection between them. The transmission ratio of each gear can be designed and optimized independently, without being affected by other gears, providing great flexibility for the design of the transmission system. In addition, this independent gear ratio design allows the system to make full use of the space resources of the electric drive axle system reducer part. Since each pair of gears can be independently arranged at different positions of the shaft, the system can flexibly adjust the size, width and position of the gears according to the actual space constraints and weight distribution requirements, avoiding the interference problem between gear sets in traditional transmissions, and achieving a more compact overall layout.

[0070] At the same time, this gear arrangement can also achieve fine matching of multiple gears while ensuring a small gear ratio range. The gear ratio range refers to the ratio of the largest transmission ratio to the smallest transmission ratio, and its value directly affects the smoothness of gear shifting and power continuity. In this embodiment, by reasonably designing the values of the first transmission ratio to the fourth transmission ratio, a smooth decreasing trend is presented, which can not only ensure that the first gear has a large enough transmission ratio to provide a large starting torque and climbing ability, but also ensure that the fourth gear has a small transmission ratio to meet the efficiency requirements of high-speed cruising, while maintaining a small gear ratio range and reducing gear shifting impact.

[0071] Based on the above-mentioned multi-gear electric drive axle system, the operation of the two shift sleeves and the power flow of the entire system in the first to fourth gear transmission states are as follows:

[0072] As Figure 2In the first gear transmission state, the first shift sleeve 46 is in the intermediate position and does not mesh with any gear; the second shift sleeve 36 moves to the first driven gear 32 and is connected in mesh with the first driven gear 32. At this time, the power flow is output from the motor 11, transmitted to the input shaft 12 through the motor shaft, transmitted to the first intermediate shaft 21 through the first transmission gear 22, and then transmitted to the third intermediate shaft 41 through the second transmission gear 23 on the first intermediate shaft 21. Since the first driving gear 42 is drivingly connected to the third intermediate shaft 41, it rotates synchronously with the third intermediate shaft 41 and is in constant mesh with the first driven gear 32. At this time, the second shift sleeve 36 is in mesh with the first driven gear 32, so that the first driven gear 32 is rigidly connected to the second intermediate shaft 31, and the rotation of the first driven gear 32 drives the second intermediate shaft 31 to rotate. Finally, the power is transmitted to the differential 51 through the third transmission gear 38 on the second intermediate shaft 31 and output to the wheel end 71 through the output shaft 61. In this process, the power is reduced through the first transmission ratio, achieving the maximum reduction ratio and providing a large output torque, which is suitable for vehicle starting and climbing and other large torque demand conditions.

[0073] As Figure 3 In the second gear transmission state, the first shift sleeve 46 is still in the intermediate position and does not mesh with any gear; the second shift sleeve 36 moves to the second driven gear 33 and is connected in mesh with the second driven gear 33. At this time, the power flow is output from the motor 11, transmitted to the input shaft 12, and finally transmitted to the third intermediate shaft 41 through the first intermediate shaft 21. Since the second driving gear 43 is also drivingly connected to the third intermediate shaft 41, it rotates synchronously with the third intermediate shaft 41 and is in constant mesh with the second driven gear 33. Since the second shift sleeve 36 is in mesh with the second driven gear 33 at this time, the rotation of the second driven gear 33 drives the second intermediate shaft 31 to rotate. Then, the power is transmitted to the differential 51 through the third transmission gear 38 on the second intermediate shaft 31 and output to the wheel end 71 through the output shaft 61. In the second gear transmission state, the power is reduced through the second transmission ratio, the reduction ratio is less than that of the first gear but greater than that of the third gear, providing moderate torque and speed characteristics, which is suitable for vehicle low-speed driving and slight slope conditions.

[0074] As Figure 4In the three-gear transmission state, the first shift sleeve 46 moves to the direction of the three-gear driving gear 44 and is in meshing connection with the three-gear driving gear 44; the second shift sleeve 36 is in the intermediate position and is not in meshing connection with any gear. At this time, the power flow is output from the motor 11, passes through the input shaft 12 and the first intermediate shaft 21, and is transmitted to the third intermediate shaft 41. Since the first shift sleeve 46 is in meshing connection with the three-gear driving gear 44, the three-gear driving gear 44 is in rigid connection with the third intermediate shaft 41 and rotates synchronously with the third intermediate shaft 41. The three-gear driving gear 44 is in constant meshing state with the three-gear driven gear 34, and the three-gear driven gear 34 is in transmission fixed connection with the second intermediate shaft 31. The power is transmitted to the second intermediate shaft 31 through the meshing of the three-gear driving gear 44 and the three-gear driven gear 34. Finally, the power is transmitted to the differential 51 through the third transmission gear 38 on the second intermediate shaft 31 and is output to the wheel end 71 through the output shaft 61. In the three-gear transmission state, the power is decelerated through the third transmission ratio, the deceleration ratio is smaller than that of the two-gear but larger than that of the four-gear, and is suitable for the working condition of high-speed driving of the vehicle.

[0075] As Figure 5 In the four-gear transmission state, the first shift sleeve 46 moves to the direction of the four-gear driving gear 45 and is in meshing connection with the four-gear driving gear 45; the second shift sleeve 36 is still in the intermediate position and is not in meshing connection with any gear. At this time, the power flow is output from the motor 11, passes through the input shaft 12 and the first intermediate shaft 21, and is transmitted to the third intermediate shaft 41. Since the first shift sleeve 46 is in meshing connection with the four-gear driving gear 45, the four-gear driving gear 45 is in rigid connection with the third intermediate shaft 41 and rotates synchronously with the third intermediate shaft 41. The four-gear driving gear 45 is in constant meshing state with the four-gear driven gear 35, and the four-gear driven gear 35 is in transmission fixed connection with the second intermediate shaft 31. The power is transmitted to the second intermediate shaft 31 through the meshing of the four-gear driving gear 45 and the four-gear driven gear 35. Finally, the power is transmitted to the differential 51 through the third transmission gear 38 on the second intermediate shaft 31 and is output to the wheel end 71 through the output shaft 61. In the four-gear transmission state, the power is decelerated through the fourth transmission ratio, the smallest deceleration ratio is provided, high output rotational speed and low output torque are realized, and the working condition of high-speed cruising of the vehicle and the like is suitable for the low-torque high-efficiency demand.

[0076] Reference Figure 6 In another preferred embodiment of the present application, a multi-gear electric drive axle system combination structure is provided, which comprises two symmetrically arranged multi-gear electric drive axle systems, and an inter-axle differential lock mechanism is arranged between the two multi-gear electric drive axle systems, which is used for realizing the interlocking or differential function of the two electric drive axle systems under specific working conditions.

[0077] In a preferred embodiment, the inter-axle differential lock mechanism comprises an interlocking transmission shaft 81, driven bevel gears 82 arranged at both ends of the interlocking transmission shaft 81, driving bevel gears 83 meshing with each driven bevel gear 82, and an interlocking sleeve 85.

[0078] Preferably, both ends of the interlocking transmission shaft 81 are respectively drivingly connected with a driven bevel gear 82, each driven bevel gear 82 is meshing with a driving bevel gear 83, the driving bevel gear 83 is arranged on a bevel gear transmission shaft 84 through a bearing, and the bevel gear transmission shaft 84 is connected with a gear on the second intermediate shaft 31 of the corresponding multi-gear electric drive axle system. The interlocking sleeve 85 is axially movable on the bevel gear transmission shaft 84 to selectively mesh with or separate from the driving bevel gear 83.

[0079] Preferably, the interlocking transmission shaft 81 is arranged in the power transmission path of the multi-gear electric drive axle system close to the motor 11 and / or away from the differential 51. More preferably, the interlocking transmission shaft 81 is arranged on the transmission link connected with the first-gear driven gear 32, which makes the interlocking transmission shaft 81 work in a high-speed and low-torque state.

[0080] Specifically, in the conventional design, the interlocking mechanism is often arranged near the differential 51 to transmit large torque, which results in a heavy and slow-responding interlocking transmission shaft. In the present embodiment, the interlocking transmission shaft 81 can be designed to be thinner and lighter due to the smaller torque transmitted, thereby reducing the rotational inertia, improving the gear shifting response speed, and improving the dynamic performance of the system. Secondly, the lighter inter-axle differential lock mechanism also reduces the weight of the whole vehicle, reduces energy consumption, and improves the economy of the whole vehicle. Further, since the interlocking sleeves 85 are arranged at both ends of the interlocking transmission shaft 81, the interlocking transmission shaft 81 will not idle in the non-interlocking state, avoiding unnecessary energy loss and improving the efficiency and reliability of the system.

[0081] In the working state, when both interlocking sleeves 85 are meshing with the corresponding driving bevel gears 83, the driving bevel gears 83 and the bevel gear transmission shaft 84 form a transmission connection, and the mechanical interlocking of the two electric drive axle systems is realized through the driven bevel gears 82 and the interlocking transmission shaft 81. At this time, the rotational speeds of the two electric drive axle systems remain synchronized, which is suitable for driving on low adhesion road surface and other working conditions that require improved traction.

[0082] When both interlocking sleeves 85 are not meshing with the driving bevel gears 83, the two electric drive axle systems can realize differential function and work independently, which is suitable for vehicle turning and other working conditions. In particular, in the differential state, the interlocking transmission shaft 81 will not idle, which can avoid unnecessary energy loss.

[0083] In addition, the inter-axle differential lock mechanism in the embodiment can be further optimized and designed, for example, a synchronizer is added to the interlocking sleeve 85 to realize a smoother interlocking process; or an electric control actuator is used to replace the mechanical actuator to realize precise control and automation of the interlocking process. At the same time, sensors can also be added to the system to monitor the speed difference of the two multi-gear electric drive axle systems, provide a basis for the interlocking control strategy, and further improve the intelligent level and use convenience of the system.

[0084] Further, the application also provides a vehicle comprising the above-mentioned multi-gear electric drive axle system or multi-gear electric drive axle system combination structure, which is preferably a pure electric commercial vehicle, such as a highway transport vehicle, an engineering vehicle, a mine vehicle, etc., which is not specifically limited in the embodiment.

[0085] Although the example embodiments have been described herein with reference to the accompanying drawings, it is to be understood that the above-described example embodiments are merely exemplary and are not intended to limit the scope of the present application. Those of ordinary skill in the art can make various changes and modifications without departing from the scope and spirit of the present application. All such changes and modifications are intended to be included within the scope of the present application as claimed in the appended claims.

[0086] In the specification provided herein, a large number of specific details are described. However, it can be understood that the embodiments of the application can be practiced without these specific details. In some instances, well-known methods, structures and techniques are not shown in detail in order not to obscure the understanding of the present specification.

[0087] Similarly, it should be appreciated that the various features of the application described herein can be implemented in any of a variety of particular embodiments, and that the application is not limited to the specific embodiments described herein. In addition, it should be understood that the features of the application described herein can be used in any combination or sub-combination with one another, and that the application is not limited to the specific combinations described herein.

[0088] Those skilled in the art will appreciate that the features described in this specification (including the accompanying claims, abstract and drawings) and / or any methods or processes described in this specification can be combined in any combination. Each feature disclosed in this specification (including the accompanying claims, abstract and drawings) can also be replaced by an alternative feature providing the same, equivalent or similar functionality. Unless otherwise stated, each feature disclosed in this specification (including the accompanying claims, abstract and drawings) is understood to be combinable with any and every other disclosed feature or combination of features.

Claims

1. A multi-speed electric drive axle system, characterized in that: It includes a motor, a differential, an output shaft, and a first intermediate shaft, a second intermediate shaft, and a third intermediate shaft arranged in parallel; The motor sequentially inputs power to the system through the first intermediate shaft, the third intermediate shaft and the second intermediate shaft, and the third intermediate shaft is loosely sleeved on the output shaft; The third intermediate shaft is provided with a first gear set and a first shifting mechanism, wherein the first shifting mechanism can be selectively connected to gears of different transmission ratios in the first gear set; The second intermediate shaft is provided with a second gear set, a second shifting mechanism and a third transmission gear, the second shifting mechanism being selectively connected to gears of different transmission ratios in the second gear set, and the third transmission gear being meshed with the differential; Each gear in the first gear set is in constant meshing with the corresponding gear in the second gear set to form multiple groups of transmission gear pairs, each group of transmission gear pairs having a different transmission ratio; through different combination states of the first shifting mechanism and the second shifting mechanism, power transmission of multiple different gears can be achieved.

2. The multi-speed electric drive axle system according to claim 1, characterized in that: It also includes an input shaft, which is transmission-connected to the motor and arranged parallel to the first intermediate shaft; A third gear set is provided on the first intermediate shaft, and the third gear set includes a first transmission gear and a second transmission gear. The first transmission gear is engaged with the input shaft, and the second transmission gear is transmission-connected to the third intermediate shaft for transmitting the power of the motor to the third intermediate shaft.

3. The multi-speed electric drive axle system according to claim 1, characterized in that: The first gear set includes a third-speed driving gear and a fourth-speed driving gear, and the third-speed driving gear and the fourth-speed driving gear are loosely mounted on the third intermediate shaft. The first shift mechanism can be selectively connected to the third-speed driving gear, the fourth-speed driving gear, or not connected to both.

4. The multi-speed electric drive axle system according to claim 3, characterized in that: The second intermediate shaft is transmission-fixedly connected with a third-gear driven gear and a fourth-gear driven gear. The third-gear driven gear is meshed with the third-gear driving gear, and the fourth-gear driven gear is meshed with the fourth-gear driving gear.

5. The multi-speed electric drive axle system according to claim 4, characterized in that: The second gear set includes a first-gear driven gear and a second-gear driven gear, and the first-gear driven gear and the second-gear driven gear are loosely mounted on the second intermediate shaft. The second shift mechanism can be selectively connected to the first-gear driven gear, the second-gear driven gear, or not connected to both.

6. The multi-speed electric drive axle system according to claim 5, characterized in that: The third intermediate shaft is transmission-fixedly connected to a first-gear driving gear and a second-gear driving gear. The first-gear driving gear is meshed with the first-gear driven gear, and the second-gear driving gear is meshed with the second-gear driven gear.

7. The multi-speed electric drive axle system according to claim 6, characterized in that: The first gear driving gear, the second gear driving gear, the third gear driving gear and the fourth gear driving gear are arranged in sequence along the axial direction of the third intermediate shaft; the first gear driven gear, the second gear driven gear, the third gear driven gear and the fourth gear driven gear are arranged in sequence along the axial direction of the second intermediate shaft.

8. The multi-speed electric drive axle system according to claim 7, characterized in that: The first gear driving gear and the first gear driven gear have a first transmission ratio, the second gear driving gear and the second gear driven gear have a second transmission ratio, the third gear driving gear and the third gear driven gear have a third transmission ratio, and the fourth gear driving gear and the fourth gear driven gear have a fourth transmission ratio; The first to fourth gear ratios decrease in sequence.

9. The multi-speed electric drive axle system according to claim 8, characterized in that: The first shift mechanism includes a first shift actuator and a first shift sleeve, wherein the first shift actuator is used to drive the first shift sleeve to move axially on the third intermediate shaft so as to selectively connect the first shift sleeve to the third gear driving gear or the fourth gear driving gear; The second shift mechanism includes a second shift actuator and a second shift sleeve. The second shift actuator is used to drive the second shift sleeve to move axially on the second intermediate shaft to selectively connect with the first gear driven gear or the second gear driven gear.

10. A multi-speed electric drive axle system combination structure, characterized in that: Comprising two symmetrically arranged multi-speed electric drive axle systems according to any one of claims 1 to 9, an inter-axle differential lock mechanism is provided between the two multi-speed electric drive axle systems, the inter-axle differential lock mechanism comprising an interlocking transmission shaft, driven bevel gears provided at both ends of the interlocking transmission shaft, a driving bevel gear meshing with each of the driven bevel gears, and an interlocking sleeve; The driving bevel gear is arranged on the bevel gear transmission shaft, the bevel gear transmission shaft is in driving connection with a gear in the second intermediate shaft, and the interlocking sleeve can selectively mesh with the driving bevel gear.

11. The multi-speed electric drive axle system combination structure according to claim 10, characterized in that: The interlocking transmission shaft is arranged in a position close to the motor and / or far away from the differential in the power transmission path of the multi-speed electric drive axle system.

12. The multi-speed electric drive axle system combination structure according to claim 10, characterized in that: When both of the interlocking sleeves are engaged with the corresponding active bevel gears, interlocking of the two multi-speed electric drive axle systems is achieved; When both of the interlocking sleeves are not engaged with the corresponding active bevel gears, the two multi-speed electric drive axle systems can achieve differential speed, and the interlocking transmission shafts do not idle.

13. A vehicle, characterized in that: It comprises the multi-speed electric drive axle system as described in any one of claims 1 to 9, or comprises the multi-speed electric drive axle system combined structure as described in any one of claims 10 to 12.

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