Single-motor five-gear transmission electric drive axle system and vehicle

Abstract

The utility model relates to a single-motor five-gear transmission electric drive axle system and a vehicle. The single-motor five-gear transmission electric drive axle system comprises a motor, a three-shaft type parallel shaft, a first gear shifting mechanism, a second gear shifting mechanism, a planet row assembly and three transmission gear sets. The three-shaft type parallel shaft comprises an input shaft, a normally engaged intermediate shaft and a sun wheel shaft; the planet row assembly comprises a sun gear, a planet gear, a planet carrier and a gear ring; the transmission gear set comprises a first driving gear, a second driving gear, a first driven gear, a second driven gear and a third driven gear, the first gear shifting mechanism is arranged between the first driving gear and the second driving gear; the first driven gear and the second driven gear are fixedly arranged on the sun wheel shaft, the sun wheel shaft is sleeved with the third driven gear in an empty mode, and the second gear shifting mechanism is arranged between the third driven gear and the planet row assembly; five transmission gears are formed through cooperation of the first gear shifting mechanism and the second gear shifting mechanism.

Description

Technical Field

[0001] The utility model relates to the technical field of vehicle power systems, and in particular to a single-motor five-speed transmission electric drive axle system and a vehicle. Background Art

[0002] With the rapid development of the new energy vehicle industry, all-electric heavy-duty commercial trucks are becoming a key industry development direction. Currently, the single-motor electric drive axles used in all-electric heavy-duty commercial vehicles mostly utilize a four-speed layout and require at least two shift actuators and gear sleeves to achieve the shift function. If the number of gears is required to be increased, three or more shift actuators and gear sleeves are usually required.

[0003] Existing four-speed electric axles typically employ a transmission mode that shifts between the main and auxiliary gearboxes, using two shift actuators and gear sleeves to achieve four gear shifts. While this structure can meet basic transmission requirements, the limited number of gears results in large speed ratio differences between adjacent gears, making it difficult to achieve efficient motor operation under all operating conditions.

[0004] In addition, during the gear shifting process, the existing electric drive axle system often requires a long speed synchronization time due to the large speed ratio difference. This not only affects the vehicle's driving performance, but also produces a large gear shift shock, reducing the service life and reliability of the transmission system.

[0005] Therefore, there is an urgent need for a new type of electric drive axle system that can achieve more gear configurations while maintaining a simple structure and low cost, and can ensure that the vehicle can maintain efficient operation of the motor within the full speed range through a reasonable speed ratio difference design, while also reducing gear shifting shock and improving driving performance. Utility Model Content

[0006] The utility model discloses a single-motor five-speed transmission electric drive axle system and a vehicle, aiming to solve the technical problems existing in the prior art.

[0007] The utility model adopts the following technical solutions:

[0008] On the one hand, an embodiment of the present invention provides a single-motor five-speed transmission electric drive axle system, comprising a motor, a three-axis parallel shaft, a first shift mechanism, a second shift mechanism, a planetary gear assembly, and three transmission gear sets;

[0009] The three-axis parallel shaft includes an input shaft, a constantly meshing intermediate shaft and a sun gear shaft arranged in parallel, the motor is connected to the input shaft, and the input shaft meshes with the constantly meshing intermediate shaft;

[0010] The planetary gear assembly includes a sun gear, planet gears, a planet carrier and a ring gear;

[0011] The three transmission gear sets include a first driving gear and a second driving gear provided on a constantly meshing intermediate shaft, and also include a first driven gear, a second driven gear and a third driven gear, wherein the third driven gear is drivingly connected to the constantly meshing intermediate shaft;

[0012] The first shift mechanism is arranged between the first driving gear and the second driving gear;

[0013] The first driven gear and the second driven gear are fixed on the sun gear shaft, the third driven gear is loosely sleeved on the sun gear shaft, and the second shift mechanism is arranged between the third driven gear and the planetary gear assembly;

[0014] Through the cooperation of the first shift mechanism and the second shift mechanism, five transmission gears are formed.

[0015] As a preferred technical solution, the first shift mechanism includes a first shift actuator, a first shift fork, a first gear sleeve and a first gear hub;

[0016] The first gear hub is fixedly arranged on the constant meshing intermediate shaft, and the first gear hub is arranged between the first driving gear and the second driving gear, and the first gear sleeve is sleeved on the first gear hub and can slide axially;

[0017] The first shift actuator drives the first gear sleeve through the first shift fork, so that the first gear sleeve can be selectively engaged with the first driving gear or the second driving gear.

[0018] As a preferred technical solution, the second shift mechanism includes a second shift actuator, a second shift fork, a second gear sleeve and a second gear hub;

[0019] The second gear hub is fixedly mounted on the sun gear shaft and is disposed between the engaging teeth of the third driven gear and the planetary carrier. The second gear sleeve is sleeved on the second gear hub and is axially slidable.

[0020] The second shift actuator drives the second gear sleeve through the second shift fork, so that the second gear sleeve can be selectively engaged with the third driven gear or the planet carrier.

[0021] As a preferred technical solution, a first reduction ratio is provided between the first driving gear and the first driven gear, a second reduction ratio is provided between the second driving gear and the second driven gear, and a third reduction ratio is provided between the third driven gear and the meshing gear of the constantly meshing intermediate shaft;

[0022] The first reduction ratio is greater than the second reduction ratio, and the second reduction ratio is greater than the third reduction ratio.

[0023] As a preferred technical solution, the sun gear shaft is fixedly arranged at one end of the sun gear, and a plurality of planetary gears are provided and arranged around the sun gear;

[0024] The planetary gears are meshed with the sun gear and the ring gear respectively, and the planetary gears are rotatably mounted on the planetary carrier;

[0025] The ring gear is fixed to the housing of the planetary gear assembly, and the output end of the planetary carrier is connected to the differential.

[0026] As a preferred technical solution, when in the first gear transmission state, the first gear sleeve is engaged with the first driving gear, the second gear sleeve is in the middle position, and is not engaged with the third driven gear and the planetary carrier. The power is transmitted to the planetary gear assembly in sequence through the first driving gear, the first driven gear, and the sun gear shaft.

[0027] As a preferred technical solution, when in the second gear transmission state, the first gear sleeve is engaged with the second driving gear, the second gear sleeve is in the middle position, and is not engaged with the third driven gear and the planetary carrier. The power is transmitted to the planetary gear assembly in sequence through the second driving gear, the second driven gear, and the sun gear shaft.

[0028] As a preferred technical solution, when in the third gear transmission state, the first gear sleeve is in the middle position and is not engaged with the first driving gear and the second driving gear, the second gear sleeve is engaged with the third driven gear, and the power is often engaged with the intermediate shaft, the third driven gear, and the sun gear shaft and transmitted to the planetary gear assembly in sequence.

[0029] As a preferred technical solution, when in the fourth gear transmission state, the first gear sleeve is engaged with the first driving gear, and the second gear sleeve is engaged with the planetary carrier. The power is transmitted in sequence through the first driving gear, the first driven gear, and the sun gear shaft, and is directly output through the planetary carrier.

[0030] As a preferred technical solution, when in the fifth gear transmission state, the first gear sleeve is engaged with the second driving gear, and the second gear sleeve is engaged with the planetary carrier. The power is transmitted in sequence through the second driving gear, the second driven gear, and the sun gear shaft, and is directly output through the planetary carrier.

[0031] On the other hand, an embodiment of the present invention further provides a vehicle, comprising a single-motor five-speed transmission electric drive axle system as described in any one of the above items.

[0032] One embodiment of the above utility model has the following advantages or beneficial effects:

[0033] The present invention mainly provides a single-motor five-speed transmission electric drive axle system and a vehicle equipped with the electric drive axle system. Compared with the existing technology, the electric drive axle system of the embodiment of the present invention only uses two shift actuators and gear sleeves to achieve power transmission of five forward gears. Compared with the solution in the existing technology that requires three or more actuators, it not only greatly reduces the system cost and structural complexity, but also improves the reliability and maintenance convenience of the system; at the same time, by setting the third gear as a transition gear between the second gear and the fourth gear, the speed ratio difference between adjacent gears is effectively reduced. The smaller speed ratio difference can not only shorten the speed synchronization time during the gear shifting process, but also significantly reduce the gear shifting impact, thereby improving the gear shifting quality and service life of the system.

[0034] In addition, the five-speed transmission structure of the embodiment of the present invention is particularly suitable for pure electric heavy-duty commercial vehicles. It can achieve the unity of economy and reliability while ensuring power performance, so that commercial vehicles can always keep the motor running in a higher efficiency range under different vehicle speed and load conditions. Through reasonable speed ratio configuration, it not only meets the vehicle's demand for high torque when starting, but also ensures the vehicle's power economy when cruising at higher speeds, thereby improving the vehicle's cruising range. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments, which constitute a part of the present invention. The schematic embodiments of the present invention and their descriptions explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0036] Figure 1 A schematic structural diagram of a single-motor five-speed transmission electric drive axle system according to an embodiment of the present invention;

[0037] Figure 2 A schematic diagram of power flow for a first gear transmission according to an embodiment of the present invention;

[0038] Figure 3 A schematic diagram of power flow for a second-gear transmission according to an embodiment of the present invention;

[0039] Figure 4 A schematic diagram of power flow for a three-speed transmission according to an embodiment of the present invention;

[0040] Figure 5 A schematic diagram of power flow of a four-speed transmission provided by an embodiment of the present utility model;

[0041] Figure 6 A power flow diagram of a five-speed transmission provided by an embodiment of the present utility model.

[0042] Description of reference numerals:

[0043] Motor 11, input shaft 12, constantly meshed intermediate shaft 13, first driving gear 21, first combining tooth 22, first driven gear 23, second driving gear 31, second combining tooth 32, second driven gear 33, third driven gear 41, third combining tooth 42, first shift actuator 51, first shift fork 52, first gear sleeve 53, first gear hub 54, second shift actuator 61, second shift fork 62, second gear sleeve 63, second gear hub 64, sun gear 71, sun gear shaft 72, planetary gears 73, planetary carrier 74, high gear combining tooth 75, ring gear 76, differential 81, left wheel end 91, right wheel end 92. DETAILED DESCRIPTION

[0044] In order to make the purpose, technical solution and advantages of the present invention more clear, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. In the description of the present invention, it should be noted that the term "or" is generally used in the sense of including "and / or" unless the content clearly indicates otherwise.

[0045] In the description of the present application, the terms "first", "second", etc. are only used to distinguish the description and should not be understood as indicating or implying relative importance.

[0046] Obviously, the embodiments described are only a part of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0047] In the field of pure electric heavy-duty commercial vehicles, existing electric drive axles usually adopt a transmission structure within four gears and require at least two shift actuators and gear sleeves to realize the shifting function. When the gear position needs to be increased, this structure often requires an increase in the number of shift actuators and gear sleeves, resulting in a complex structure and increased costs. In addition, due to the small number of gears, the speed ratio difference between adjacent gears is large, which not only affects the shifting quality, but also makes it difficult to ensure the efficient operation of the motor in the full operating range.

[0048] To address the aforementioned issues, the present invention provides a single-motor, five-speed electric drive axle system. This system utilizes a three-axis parallel shaft and single-stage planetary gearbox, employing two shift mechanisms to achieve five forward gears. Compared to existing technologies, this significantly reduces system cost and structural complexity, effectively narrowing the speed ratio differences between adjacent gears.

[0049] refer to Figure 1In a preferred embodiment, a single-motor five-speed transmission electric drive axle system includes a motor 11, a three-axis parallel shaft, three sets of transmission gear sets, a planetary gear assembly and two sets of shifting mechanisms, wherein the three-axis parallel shaft is arranged in the system main box, the planetary gear assembly is arranged in the system auxiliary box, and the two sets of shifting mechanisms include a first shifting mechanism and a second shifting mechanism. The first shifting mechanism controls the switching of two gears, and the second shifting mechanism controls the switching of third gear and high gear. Through the cooperation of the first shifting mechanism and the second shifting mechanism, the arrangement and combination form the switching of five forward gears.

[0050] It should be noted that the main box and the auxiliary box in the embodiment of the present application are a unified transmission system, which is not for the purpose of simply multiplying the gears. The three-axis parallel shaft structure in the main box and the planetary gear assembly in the auxiliary box work together to achieve transmission of five gears.

[0051] In a preferred embodiment, the three-axis parallel shaft includes an input shaft 12, a constantly meshed intermediate shaft 13 and a sun gear shaft 72; the three transmission gear sets include a first driving gear 21 and a first driven gear 23, a second driving gear 31 and a second driven gear 33, and a third driven gear 41, wherein one end of the first driving gear 21 is provided with a first coupling tooth 22, one end of the second driving gear 31 is provided with a second coupling tooth 32, and one end of the third driven gear 41 is provided with a third coupling tooth 42; the planetary gear assembly includes a sun gear 71, planetary gears 73, a planet carrier 74 and a ring gear 76, the sun gear 71 is connected to the three transmission gear sets through the sun gear shaft 72, and one end of the planet carrier 74 is provided with a high gear coupling tooth 75.

[0052] In a preferred embodiment, the output end of the motor 11 is fixedly connected to the input shaft 12 as the power input end; the input shaft 12 maintains a constant meshing state with the constant meshing intermediate shaft 13 for transmitting power to the constant meshing intermediate shaft 13; the constant meshing intermediate shaft 13 is sequentially provided with a first driving gear 21 and a second driving gear 31, wherein the first driving gear 21 and the second driving gear 31 are loosely provided on the constant meshing intermediate shaft 13, and one end of the constant meshing intermediate shaft 13 is transmission-connected to the third driven gear 41, that is, the constant meshing intermediate shaft 13 is provided with a gear that is constantly meshed with the third driven gear 41.

[0053] In this embodiment, the motor 11 includes a stator, a rotor, a coil, a rotor shaft and other structures, wherein the rotor shaft serves as the power output end of the motor 11 and is connected to the input shaft 12 in the three-axis parallel shaft. Specifically, the specific model, structure or specification of the motor 11 can be selected and configured according to the power performance requirements of the whole vehicle, and is not specifically limited in this embodiment.

[0054] In a preferred embodiment, the first shifting mechanism is arranged between the first driving gear 21 and the second driving gear 31, and the first shifting mechanism can selectively engage with the first combining tooth 22 or the second combining tooth 32 to realize the switching of the two gears of the main box; the power is transmitted to the sun gear shaft 72 through the components on the constant meshing intermediate shaft 13, and the first driven gear 23 and the second driven gear 33 are fixed on the sun gear shaft 72, and can directly transmit power to the planetary gear assembly. The third driven gear 41 is loosely mounted on the sun gear shaft 72, and the second shifting mechanism is arranged between the third driven gear 41 and the planetary gear assembly. The second shifting mechanism can selectively engage with the third combining tooth 42 or the high gear combining tooth 75 to realize the switching of the third gear and the high gear of the auxiliary box.

[0055] In a preferred embodiment, a first reduction ratio is established between the first driving gear 21 and the first driven gear 23, a second reduction ratio is established between the second driving gear 31 and the second driven gear 33, and a third reduction ratio is established between the third driven gear 41 and the meshing gear of the constantly meshing intermediate shaft 13. Those skilled in the art will understand that a greater reduction ratio results in greater output torque. The specific reduction ratios and the number of teeth on each transmission tooth are not limited in this embodiment, and those skilled in the art may adapt these ratios based on actual application scenarios.

[0056] Preferably, the first reduction ratio, the second reduction ratio, and the third reduction ratio are different.

[0057] More preferably, the first reduction ratio is greater than the second, and the second reduction ratio is greater than the third. The larger first reduction ratio satisfies the high torque requirements of heavy commercial vehicles during starting operations; the intermediate second reduction ratio is suitable for frequent acceleration and deceleration in urban conditions; and the smaller third reduction ratio improves power economy during high-speed cruising. This decreasing reduction ratio design ensures a reasonable speed ratio step between adjacent gears. By combining these three basic reduction ratios with the speed ratio characteristics of the planetary gear assembly, five reasonably distributed transmission gears can be formed, ensuring both starting performance and economic efficiency.

[0058] In a preferred embodiment, the first gear shift mechanism includes a first gear shift actuator 51, a first gear shift fork 52, a first gear sleeve 53 and a first gear hub 54; wherein, the first gear hub 54 is fixedly arranged on the constant meshing intermediate shaft 13, and the first gear hub 54 is arranged between the first driving gear 21 and the second driving gear 31, and a spline is provided on the outer circumferential surface of the first gear hub 54. The first gear sleeve 53 is sleeved on the first gear hub 54 and can slide axially. The first gear sleeve 53 has an internal spline that cooperates with the spline. This spline cooperation can both transmit torque and allow the first gear sleeve 53 to slide freely in the axial direction.

[0059] The first gear sleeve 53 is provided with internal splines at both ends, which selectively engage with the coupling teeth (i.e., the first coupling teeth 22 and the second coupling teeth 32) on the first and second driving gears 21 and 31. The first shift actuator 51 drives the first gear sleeve 53 to move axially via the first shift fork 52. When the first gear sleeve 53 moves leftward, the internal splines on its left end engage with the first coupling teeth 22 of the first driving gear 21, forming a rigid connection between the first driving gear 21 and the constant mesh intermediate shaft 13. When the first gear sleeve 53 moves rightward, the internal splines on its right end engage with the second coupling teeth 32 of the second driving gear 31, forming a rigid connection between the second driving gear 31 and the constant mesh intermediate shaft 13.

[0060] In this embodiment, the first shift actuator 51 is preferably an electric shift actuator, which features fast response and high control precision. The electric shift actuator receives shift commands from a controller and drives the first shift fork 52 to reciprocate, thereby achieving precise positioning of the first gear sleeve 53. The first shift fork 52 is provided with a fork groove that mates with the first gear sleeve 53, driving the first gear sleeve 53 axially.

[0061] In a preferred embodiment, the second shift mechanism is located at the input end of the planetary gear assembly and similarly utilizes a synchronizer design. Specifically, the second shift mechanism comprises a second shift actuator 61, a second shift fork 62, a second gear sleeve 63, and a second gear hub 64. The second gear hub 64 is fixed to the sun gear shaft 72, positioned between the engaging teeth of the idler third driven gear 41 and the planetary carrier 74 (i.e., the high-speed engaging teeth 75). The outer circumference of the second gear hub 64 is provided with splines that mate with the internal splines of the second gear sleeve 63.

[0062] Preferably, both ends of the second gear sleeve 63 are provided with internal splines that can selectively engage with the third coupling tooth 42 or the high-gear coupling tooth 75. The second shift actuator 61 drives the second gear sleeve 63 to move axially via the second shift fork 62. When the second gear sleeve 63 moves leftward, the internal splines on its left end engage with the third coupling tooth 42 of the third driven gear 41. At this time, the third driven gear 41 and the sun gear shaft 72 form a rigid connection, and power is transmitted to the planetary gear assembly through the sun gear shaft 72. When the second gear sleeve 63 moves rightward, the internal splines on its right end engage with the high-gear coupling tooth 75. At this time, the planetary carrier 74 and the sun gear shaft 72 form a rigid connection, and power is directly transmitted from the sun gear shaft 72 to the planetary carrier 74, realizing direct transmission.

[0063] Preferably, the structure and configuration of the second shift actuator 61 and the second shift fork 62 may be the same as or different from those of the first shift actuator 51 and the first shift fork 52 , which is not specifically limited herein.

[0064] In this embodiment, the second shifting mechanism allows for flexible switching of the power transmission path as needed: either transmitting power to the sun gear shaft 72 via the third driven gear 41, and then reducing power output through the planetary gear assembly; or directly coupling with the planetary carrier 74 for direct power output. By cooperating with the first shifting mechanism, five gear shifting and transmission positions are ultimately achieved.

[0065] In a preferred embodiment, the planetary gear assembly adopts a single planetary gear arrangement, wherein one end of a sun gear shaft 72 is fixedly connected to a sun gear 71 for inputting power. Multiple planetary gears 73 are circumferentially mounted on a planetary carrier 74, each of which meshes with both the external teeth of the sun gear 71 and the internal teeth of a ring gear 76, thereby forming a complete planetary transmission mechanism. Ring gear 76 is fixed to the planetary gear assembly housing and serves as a torsion-resistant support. Planetary carrier 74 serves as the output member of the planetary gear assembly, with its output end connected to the input of a differential 81.

[0066] When power is input from the sun gear 71, under the condition that the ring gear 76 is fixed, the planetary gear 73 rotates around its own axis and revolves around the sun gear 71, driving the planetary carrier 74 to reduce the output; when the second gear sleeve 63 is engaged with the planetary carrier 74, the planetary gear assembly can achieve overall synchronous rotation, that is, direct transmission working condition.

[0067] In a preferred embodiment, the differential 81 is located after the output of the planetary carrier 74 and is used to distribute power to the left and right wheels 91, 92. Specifically, when the vehicle turns, the differential 81 automatically adjusts the speed difference between the left and right wheels 91, 92, reducing the speed of the inner wheels and increasing the speed of the outer wheels, thereby ensuring smooth cornering. The differential 81 also has a torque distribution function, effectively distributing power to the left and right wheels 91, 92 based on road adhesion conditions, thereby improving the vehicle's dynamic performance and driving stability.

[0068] In this embodiment, the specific structure and specifications of the differential 81 are not specifically limited, and those skilled in the art can make adaptive adjustments according to actual needs.

[0069] In a preferred embodiment, when in the first gear transmission state, the first gear sleeve 53 is engaged with the first coupling tooth 22 of the first driving gear 21, and the second gear sleeve 63 is in the middle position and is not engaged with the third coupling tooth 42 of the third driven gear 41 and the high gear coupling tooth 75 of the planetary carrier 74.

[0070] refer to Figure 2 , where red represents the direction of power flow. In the first gear transmission state, the power transmission path is as follows:

[0071] The power output by the motor 11 is first transmitted to the constantly meshing intermediate shaft 13 that is constantly meshing with it through the input shaft 12. At this time, the first gear sleeve 53 is engaged with the first coupling teeth 22, so that the first driving gear 21 and the constantly meshing intermediate shaft 13 form a rigid connection. Since the first driving gear 21 is meshed with the first driven gear 23, the power is transmitted to the first driven gear 23 after the first stage of reduction.

[0072] Since the first driven gear 23 is fixed on the sun gear shaft 72, the power is directly transmitted to the sun gear shaft 72, and then transmitted to the sun gear 71 fixed to the sun gear shaft 72. At this time, the second gear sleeve 63 is in the middle position, neither engaged with the third driven gear 41 nor engaged with the planetary carrier 74, so the power can only be transmitted through the transmission path of sun gear 71-planetary gear 73-ring gear 76.

[0073] In the planetary gear assembly, the sun gear 71 drives the multiple planetary gears 73. Because the ring gear 76 is fixed to the housing, the planetary gears 73 rotate about their own axes while simultaneously driving the planetary carrier 74 in orbit. This motion forms a reduction mechanism within the planetary gear assembly, further reducing the output speed and increasing the output torque. Finally, the power reduced by the planetary carrier 74 is transmitted to the differential 81 and distributed to the left and right wheels 91 and 92.

[0074] Preferably, the first gear is used as the starting gear, and the power undergoes two decelerations during the transmission process. First, the deceleration is between the first driving gear 21 and the first driven gear 23 (the first reduction ratio is the largest), and then the deceleration is performed by the planetary gear assembly. Therefore, it has the largest comprehensive reduction ratio, ensuring that the vehicle has a sufficiently large output torque when starting and climbing.

[0075] In a preferred embodiment, when in the second gear transmission state, the first gear sleeve 53 is engaged with the second driving gear 31 , and the second gear sleeve 63 is in a middle position and is not engaged with the third driven gear 41 and the planet carrier 74 .

[0076] refer to Figure 3 , where red represents the power flow direction. In the second gear transmission state, the power transmission path is as follows:

[0077] The power output by the motor 11 is first transmitted to the constantly meshing intermediate shaft 13 that is constantly meshing with it through the input shaft 12. At this time, the first gear sleeve 53 is engaged with the second coupling teeth 32, so that the second driving gear 31 is rigidly connected to the constantly meshing intermediate shaft 13. Since the second driving gear 31 is meshed with the second driven gear 33, the power is transmitted to the second driven gear 33 after the second stage of reduction.

[0078] Since the second driven gear 33 is also fixed on the sun gear shaft 72, the power is directly transmitted to the sun gear shaft 72, and then transmitted to the sun gear 71 fixed to the sun gear shaft 72. At this time, the second gear sleeve 63 is in the middle position, neither engaged with the third driven gear 41 nor engaged with the planetary carrier 74, so the power is still transmitted through the transmission path of sun gear 71-planetary gear 73-ring gear 76.

[0079] In the planetary gear assembly, the transmission principle and process are the same as those of first gear and will not be repeated here.

[0080] Although the power transmission path of the second gear is similar to that of the first gear, both undergo double deceleration through the gear set and the planetary gear set, but since the second reduction ratio is smaller than the first reduction ratio, the comprehensive reduction ratio of the second gear is smaller than that of the first gear, making the second gear more suitable for the acceleration process of the vehicle after completing the start, which not only ensures sufficient output torque but also increases the output speed.

[0081] In a preferred embodiment, when in the third gear transmission state, the first gear sleeve 53 is in the middle position and is not engaged with the first driving gear 21 and the second driving gear 31 , and the second gear sleeve 63 is engaged with the third driven gear 41 .

[0082] refer to Figure 4 , where red represents the direction of power flow. In the third gear transmission state, the power transmission path is as follows:

[0083] The power output by the motor 11 is first transmitted to the constantly meshing intermediate shaft 13 that is constantly meshing with the input shaft 12. At this time, the first gear sleeve 53 is neither engaged with the first driving gear 21 nor with the second driving gear 31. The power is directly transmitted to the third driven gear 41 through the constantly meshing intermediate shaft 13. After the third stage of reduction, the power is transmitted to the third driven gear 41.

[0084] Because the second gear sleeve 63 is engaged with the third driven gear 41, the third driven gear 41, which is loosely mounted on the sun gear shaft 72, forms a rigid connection with the sun gear shaft 72, thereby transmitting power to the sun gear shaft 72 and then to the sun gear 71, which is fixedly connected to the sun gear shaft 72. Power is further transmitted through the transmission path of sun gear 71, planetary gears 73, and ring gear 76.

[0085] In the planetary gear assembly, the transmission principle is the same as the first two gears: the sun gear 71 drives multiple planetary gears 73 to rotate. Since the ring gear 76 is fixed to the housing, the planetary gears 73 rotate around their own axes while driving the planetary carrier 74 to revolve. The planetary gear assembly continues to play the role of a reducer. The decelerated power is transmitted from the planetary carrier 74 to the differential 81 and finally distributed to the left and right wheels.

[0086] Because the third reduction ratio is smaller than the second reduction ratio, the overall reduction ratio of third gear is smaller than that of second gear. As a transitional gear, the reduction ratio design of third gear avoids an excessively large speed ratio span between second and fourth gears while providing a transmission gear suitable for medium speed conditions, thereby improving the vehicle's power performance and economy.

[0087] In a preferred embodiment, when in the fourth gear transmission state, the first gear sleeve 53 is engaged with the first driving gear 21 , and the second gear sleeve 63 is engaged with the planet carrier 74 .

[0088] refer to Figure 5 , where red represents the direction of power flow. In the fourth gear transmission state, the power transmission path is as follows:

[0089] The power output by the motor 11 is first transmitted to the constantly meshing intermediate shaft 13 that is constantly meshing with it through the input shaft 12. At this time, the first gear sleeve 53 is engaged with the first coupling teeth 22, so that the first driving gear 21 and the constantly meshing intermediate shaft 13 form a rigid connection. Since the first driving gear 21 is meshed with the first driven gear 23, the power is transmitted to the first driven gear 23 after the first stage of reduction.

[0090] Since the first driven gear 23 is fixed on the sun gear shaft 72, the power is directly transmitted to the sun gear shaft 72. At this time, the second gear sleeve 63 is engaged with the high gear coupling tooth 75 of the planet carrier 74, so that the planet carrier 74 and the sun gear shaft 72 are rigidly connected. This connection method makes the sun gear shaft 72, sun gear 71, planet gear 73 and planet carrier 74 form a whole. The planetary gear assembly no longer plays a deceleration role, but rotates synchronously as a whole.

[0091] In fourth gear, power undergoes only a single reduction between the first driving gear 21 and the first driven gear 23. It is then directly output to the differential 81 via the planetary carrier 74, which is rigidly connected to the sun gear shaft 72, and ultimately distributed to the left and right wheels. This direct drive in fourth gear avoids secondary reduction in the planetary gear assembly, resulting in a higher output speed.

[0092] Although the fourth gear's comprehensive reduction ratio uses the largest first reduction ratio, its comprehensive reduction ratio is actually smaller than that of the third gear because the deceleration effect of the planetary gear assembly is cancelled.

[0093] In a preferred embodiment, when in the fifth gear transmission state, the first gear sleeve 53 is engaged with the second driving gear 31 , and the second gear sleeve 63 is engaged with the planet carrier 74 .

[0094] refer to Figure 6 , where red represents the direction of power flow. In the fifth gear transmission state, the power transmission path is as follows:

[0095] The power output by the motor 11 is first transmitted to the constantly meshing intermediate shaft 13 that is constantly meshing with it through the input shaft 12. At this time, the first gear sleeve 53 is engaged with the second coupling teeth 32, so that the second driving gear 31 is rigidly connected to the constantly meshing intermediate shaft 13. Since the second driving gear 31 is meshed with the second driven gear 33, the power is transmitted to the second driven gear 33 after the second stage of reduction.

[0096] Because the second driven gear 33 is fixed to the sun gear shaft 72, power is directly transmitted to the sun gear shaft 72. At this time, the second gear sleeve 63 engages with the high-gear coupling teeth 75 of the planet carrier 74, forming a rigid connection between the planet carrier 74 and the sun gear shaft 72. Similar to the fourth-gear transmission state, this connection method makes the sun gear shaft 72, sun gear 71, planet gears 73 and planet carrier 74 form a whole. The planetary gear assembly no longer plays a deceleration role, but rotates synchronously as a whole.

[0097] In this transmission state, the power is only decelerated between the second driving gear 31 and the second driven gear 33, and then directly output to the differential 81 through the planetary carrier 74 rigidly connected to the sun gear shaft 72, and finally distributed to the left and right wheels, avoiding the secondary deceleration of the planetary gear assembly, thereby obtaining the highest output speed.

[0098] During the fifth-gear transmission, not only is a smaller second reduction ratio employed, but the deceleration effect of the planetary gear assembly is also eliminated. Therefore, fifth gear, as the highest gear, has the lowest overall reduction ratio. This transmission method is particularly well-suited for high-speed cruising, fully utilizing the high-speed performance of motor 11. Furthermore, by reducing the number of transmission links, transmission efficiency is maximized, contributing to improved vehicle economy.

[0099] Compared with the existing technology, the single-motor five-speed transmission electric drive axle system provided by the embodiment of the utility model only uses two shift actuators and gear sleeves to achieve power transmission of five forward gears. Compared with the solution in the existing technology that requires three or more actuators, it not only greatly reduces the system cost and structural complexity, but also improves the reliability and maintenance convenience of the system; at the same time, by setting the third gear as a transition gear between the second gear and the fourth gear, the speed ratio difference between adjacent gears is effectively reduced. The smaller speed ratio difference can not only shorten the speed synchronization time during the shifting process, but also significantly reduce the shifting impact, thereby improving the shifting quality and service life of the system.

[0100] In one embodiment of the present invention, a vehicle is provided, which is equipped with the above-mentioned single-motor five-speed transmission electric drive axle system. Preferably, the vehicle in this embodiment is a purely electric commercial vehicle, such as an electric truck, electric bus, electric transport vehicle, electric tractor, etc. Based on the above-mentioned electric drive axle system, the vehicle can meet the driving requirements of different working conditions. Among them, the low gear position can meet the needs of frequent starting and stopping and climbing, and the high gear position can achieve economical cruising and improve the driving range. On slopes or under loaded conditions, sufficient power output can be ensured through reasonable gear selection.

[0101] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely illustrative and are not intended to limit the scope of the present application. Various changes and modifications may be made therein by those skilled in the art 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 required by the appended claims.

[0102] In the description provided herein, a large number of specific details are described. However, it is understood that the embodiments of the present application can be practiced without these specific details. In some instances, well-known methods, structures, and techniques are not shown in detail so as not to obscure the understanding of this description.

[0103] Similarly, it should be understood that in order to streamline the present application and aid in understanding one or more of the various utility model aspects, in the description of the exemplary embodiments of the present application, the various features of the present application are sometimes grouped together into a single embodiment, figure, or description thereof. However, this method of the present application should not be interpreted as reflecting the following intention: that the application claimed for protection requires more features than the features explicitly recited in each claim. More precisely, as reflected in the corresponding claims, its utility model point is that the corresponding technical problem can be solved with features that are less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby expressly incorporated into the specific embodiment, with each claim itself serving as a separate embodiment of the present application.

[0104] Those skilled in the art will understand that, except where mutually exclusive, all features disclosed in this specification (including the accompanying claims, abstract, and drawings) and all processes or units of any method or apparatus disclosed herein may be combined in any combination. Unless expressly stated otherwise, each feature disclosed in this specification (including the accompanying claims, abstract, and drawings) may be replaced by an alternative feature that provides the same, equivalent, or similar purpose.

Claims

1. A single-motor five-speed transmission electric drive axle system, characterized in that: It includes a motor, a three-axis parallel shaft, a first gear shift mechanism, a second gear shift mechanism, a planetary gear assembly and three transmission gear sets; The three-axis parallel shaft includes an input shaft, a constantly meshing intermediate shaft and a sun gear shaft arranged in parallel, the motor is connected to the input shaft, and the input shaft meshes with the constantly meshing intermediate shaft; The planetary gear assembly includes a sun gear, planetary gears, a planet carrier and a ring gear; The three transmission gear sets include a first driving gear and a second driving gear provided on the constant meshing intermediate shaft, and also include a first driven gear, a second driven gear and a third driven gear, wherein the third driven gear is in transmission connection with the constant meshing intermediate shaft; The first shift mechanism is provided between the first driving gear and the second driving gear; The first driven gear and the second driven gear are fixed on the sun gear shaft, the third driven gear is loosely sleeved on the sun gear shaft, and the second shifting mechanism is provided between the third driven gear and the planetary gear assembly; The cooperation between the first shift mechanism and the second shift mechanism forms five transmission gears.

2. The single-motor five-speed transmission electric drive axle system according to claim 1, characterized in that: The first shift mechanism includes a first shift actuator, a first shift fork, a first gear sleeve and a first gear hub; The first gear hub is fixedly arranged on the constant meshing intermediate shaft, and the first gear hub is arranged between the first driving gear and the second driving gear, and the first gear sleeve is sleeved on the first gear hub and can slide axially; The first shift actuator drives the first gear sleeve through the first shift fork, so that the first gear sleeve can be selectively engaged with the first driving gear or the second driving gear.

3. The single-motor five-speed transmission electric drive axle system according to claim 2, characterized in that: The second shift mechanism includes a second shift actuator, a second shift fork, a second gear sleeve and a second gear hub; The second gear hub is fixedly mounted on the sun gear shaft and is disposed between the engaging teeth of the third driven gear and the planetary carrier, and the second gear sleeve is sleeved on the second gear hub and is axially slidable; The second shift actuator drives the second gear sleeve through the second shift fork, so that the second gear sleeve can be selectively engaged with the third driven gear or the planet carrier.

4. The single-motor five-speed transmission electric drive axle system according to claim 1, characterized in that: There is a first reduction ratio between the first driving gear and the first driven gear, a second reduction ratio between the second driving gear and the second driven gear, and a third reduction ratio between the third driven gear and the meshing gear of the constantly meshing intermediate shaft; The first reduction ratio is greater than the second reduction ratio, and the second reduction ratio is greater than the third reduction ratio.

5. The single-motor five-speed transmission electric drive axle system according to claim 1, characterized in that: The sun gear shaft is fixedly arranged at one end of the sun gear, and a plurality of planetary gears are provided and arranged around the sun gear; The planetary gears are respectively engaged with the sun gear and the ring gear, and the planetary gears are rotatably mounted on the planetary carrier; The ring gear is fixed to the housing of the planetary gear assembly, and the output end of the planetary carrier is connected to the differential.

6. The single-motor five-speed transmission electric drive axle system according to claim 3, characterized in that: When in the first gear transmission state, the first gear sleeve is engaged with the first driving gear, the second gear sleeve is in the middle position and is not engaged with the third driven gear and the planetary carrier, and power is transmitted to the planetary gear assembly through the first driving gear, the first driven gear, and the sun gear shaft in sequence.

7. The single-motor five-speed transmission electric drive axle system according to claim 3, characterized in that: When in the second gear transmission state, the first gear sleeve is engaged with the second driving gear, the second gear sleeve is in the middle position, and is not engaged with the third driven gear and the planetary carrier, and the power is transmitted to the planetary gear assembly in sequence through the second driving gear, the second driven gear, and the sun gear shaft.

8. The single-motor five-speed transmission electric drive axle system according to claim 3, characterized in that: When in the third gear transmission state, the first gear sleeve is in the middle position and is not engaged with the first driving gear and the second driving gear, the second gear sleeve is engaged with the third driven gear, and power is transmitted to the planetary gear assembly in sequence through the constantly meshed intermediate shaft, the third driven gear, and the sun gear shaft.

9. The single-motor five-speed transmission electric drive axle system according to claim 3, characterized in that: When in the fourth gear transmission state, the first gear sleeve is engaged with the first driving gear, and the second gear sleeve is engaged with the planet carrier. Power is transmitted in sequence through the first driving gear, the first driven gear, and the sun gear shaft, and is directly output through the planet carrier.

10. The single-motor five-speed transmission electric drive axle system according to claim 3, characterized in that: When in the fifth gear transmission state, the first gear sleeve is engaged with the second driving gear, and the second gear sleeve is engaged with the planet carrier. Power is transmitted in sequence through the second driving gear, the second driven gear, and the sun gear shaft, and is directly output through the planet carrier.

11. A vehicle, characterized in that: The vehicle includes a single-motor five-speed transmission electric drive axle system as described in any one of claims 1 to 10.

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