Multi-gear duplex electric drive axle system and vehicle

Abstract

The utility model relates to a multi-gear duplex electric drive axle system and a vehicle, the multi-gear duplex electric drive axle system is suitable for a pure electric drive heavy commercial truck, and the system comprises a four-gear double-motor electric drive axle, a transmission drive axle, an inter-axle differential mechanism and a differential lock mechanism; the four-gear double-motor electric drive axle is in transmission connection with the transmission drive axle; the inter-axle differential mechanism and the differential lock mechanism are arranged between the four-gear double-motor electric drive axle and the transmission drive axle; the differential lock mechanism is used for locking or unlocking the inter-axle differential mechanism, and when the differential lock mechanism is in an unlocking state, the rotating speed difference exists between the four-gear double-motor electric drive axle and the transmission drive axle.

Description

Technical Field

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

[0002] In the prior art, most four-wheel drive pure electric heavy-duty commercial vehicles adopt the layout of two electric drive axles. This layout has the following major defects:

[0003] (1) The inter-axle differential and differential lock functions between the two axles cannot be realized; when driving on low-adhesion and muddy roads, since there is no differential function between the two drive axles, when the wheels of one drive axle slip, the other drive axle cannot output sufficient driving force, causing the whole vehicle to easily fall into landslides or be difficult to get out of trouble; at the same time, under heavy-load climbing conditions, it is also easy for one drive axle to slip and the other drive axle to be unable to output sufficient driving force, making it impossible to ensure that the vehicle can climb the slope smoothly.

[0004] (2) The manufacturing cost of the vehicle power transmission system is relatively high. The use of two independent electric drive axles requires two complete power transmission systems, including motors, reducers, etc. The manufacturing and procurement costs are relatively high, which affects the purchase price of the vehicle.

[0005] (3) The vehicle layout and installation space requirements are relatively high; the two electric drive axles each occupy a certain longitudinal and lateral installation space, which imposes certain restrictions on the layout of the vehicle and increases the difficulty of vehicle design.

[0006] Based on the above defects, it is necessary to design a new four-wheel drive system to overcome the problems existing in the prior art, thereby improving the obstacle crossing performance and manufacturing economy of the whole vehicle. Utility Model Content

[0007] The utility model discloses a multi-speed dual-connected electric drive axle system and a vehicle equipped with the system, aiming to solve the technical problems existing in the prior art.

[0008] The utility model adopts the following technical solutions:

[0009] On the one hand, the embodiment of the utility model provides a multi-speed dual-motor electric drive axle system, including a four-speed dual-motor electric drive axle, a transmission drive axle, an inter-axle differential, and a differential lock mechanism;

[0010] The four-speed dual-motor electric drive axle is drivingly connected to the transmission drive axle;

[0011] The inter-axle differential and differential lock mechanism are arranged between the four-speed dual-motor electric drive axle and the transmission drive axle;

[0012] The differential lock mechanism is used to lock or unlock the inter-axle differential. When the differential lock mechanism is in the unlocked state, there is a speed difference between the four-speed dual-motor electric drive axle and the transmission drive axle.

[0013] As a preferred technical solution, the four-speed dual-motor electric drive bridge includes dual motors, a first shift mechanism, and a second shift mechanism;

[0014] The dual motors, the first shift mechanism and the second shift mechanism are all symmetrically arranged, and the dual motors are connected to the inter-axle differential through the first shift mechanism and the second shift mechanism in sequence;

[0015] The first shift mechanism includes two sets of gear shaft systems with different reduction ratios, and each set of gear shaft systems can be selectively connected or disconnected with the dual motor transmission;

[0016] The second shift mechanism includes a planetary gear train, in which an inner gear ring can be selectively engaged or not engaged with a planet carrier or a housing.

[0017] As a preferred technical solution, the first shift mechanism includes:

[0018] - a first gear shaft system, comprising a first driving gear and a first driven gear meshing therewith, wherein one end of the first driven gear is provided with a first coupling tooth;

[0019] - a second gear shaft system, comprising a second driving gear and a second driven gear meshing therewith, wherein one end of the second driven gear is provided with a second coupling tooth; a reduction ratio between the second driven gear and the second driving gear is smaller than a reduction ratio between the first driven gear and the first driving gear;

[0020] - a first gear hub, which can be selectively drivingly connected to the first coupling gear or the second coupling gear;

[0021] - A first gear shift actuator, used to change the transmission connection relationship of the first gear hub.

[0022] As a preferred technical solution, the second shifting mechanism includes:

[0023] -Planetary gear train, comprising a housing, a sun gear, planetary gears, a planetary carrier and an inner gear ring;

[0024] - a third coupling tooth, connected to the housing;

[0025] - a fourth coupling tooth connected to the planet carrier;

[0026] - A second gear hub, one end of which is connected to the inner gear ring, and the other end of which can be selectively connected to the third combined tooth or the fourth combined tooth in driving connection;

[0027] - A second gear shift actuator, used to change the transmission connection relationship of the second gear hub.

[0028] As a preferred technical solution, the input end of the second shift mechanism is transmission-connected to the output end of the first shift mechanism, and the output end of the second shift mechanism is transmission-connected to the inter-axle differential.

[0029] As a preferred technical solution, the inter-axle differential comprises a first half-axle gear, a second half-axle gear and an inter-axle half-axle, and the second half-axle gear is drivingly connected to the inter-axle half-axle;

[0030] The first side gear is used to transfer power to the four-speed dual-motor electric drive axle;

[0031] The second side gear is used to transfer power to the drive axle.

[0032] As a preferred technical solution, the four-speed dual-motor electric drive axle is configured as a middle axle, and the middle axle also includes a middle axle left tire, a middle axle right tire, a middle axle differential, a middle axle driving bevel gear, a middle axle driven bevel gear, a third driving gear and a third driven gear;

[0033] The third driving gear is drivingly connected with the first half-shaft gear and meshes with the third driven gear;

[0034] The middle axle driving bevel gear is drivingly connected with the third driven gear and meshes with the middle axle driven bevel gear;

[0035] The input end of the middle bridge differential is transmission-connected with the middle bridge driven bevel gear, and the output end of the middle bridge differential is transmission-connected with the left tire of the middle bridge and the right tire of the middle bridge respectively.

[0036] As a preferred technical solution, the transmission drive axle is configured as a rear axle, and the rear axle also includes a rear axle input shaft, a rear axle driving bevel gear, a rear axle driven bevel gear, a rear axle left tire, a rear axle right tire and a rear axle differential;

[0037] The input end of the rear axle input shaft is connected to the output end of the middle axle through a transmission shaft;

[0038] The rear axle driving bevel gear is connected to the rear axle input shaft and meshes with the rear axle driven bevel gear;

[0039] The input end of the rear axle differential is drivingly connected to the rear axle driven bevel gear, and the output end of the rear axle differential is drivingly connected to the rear axle left tire and the rear axle right tire respectively.

[0040] As a preferred technical solution, the differential lock mechanism is arranged between the transmission shaft and the inter-axle differential, and the differential lock mechanism includes a servo cylinder, a differential lock fork, a spline hub, a differential lock sleeve, lock sleeve dog teeth, and a third driving gear dog teeth;

[0041] The differential lock sleeve is slidably connected to the spline hub, and the servo cylinder drives the differential lock sleeve to slide through the differential lock fork;

[0042] One end of the differential lock sleeve is provided with lock sleeve dog teeth, and one end of the third driving gear is provided with third driving gear dog teeth. When the differential lock sleeve slides on the spline hub, the lock sleeve dog teeth can selectively engage or not engage with the third driving gear dog teeth.

[0043] On the other hand, an embodiment of the utility model further provides a vehicle, comprising a multi-speed dual-connected electric drive axle system as described in any one of the above items.

[0044] One embodiment of the above utility model has the following advantages or beneficial effects:

[0045] The utility model mainly provides a multi-speed dual-axle electric drive axle system, which is suitable for pure electric heavy-duty commercial trucks. Due to the use of a dual-axle structure in which a four-speed dual-motor electric drive axle is connected in series with a transmission drive axle, and the use of an inter-axle differential and a differential lock mechanism, the system can maintain high stability and reliability under different working conditions; when the differential lock mechanism is in a locked state, the system forms an active-active four-wheel drive mode, ensuring traction and passability under complex road conditions, and improving the stability and reliability of the vehicle.

[0046] Furthermore, the multi-speed configuration can provide efficient power transmission, reduce energy loss, and improve the energy efficiency of the entire system, which not only helps to extend the battery life, but also reduces the vehicle's energy consumption costs.

[0047] Thanks to the dual-motor system, the multi-speed dual-electric drive axle system provided by the utility model can provide higher system power to meet the power needs of heavy trucks to improve overall performance; the lockable and unlockable design of the differential lock mechanism enables the vehicle to be flexibly adjusted according to actual road conditions; on low adhesion or muddy roads, the locking differential can provide greater traction to help the vehicle get out of trouble; and on ordinary roads, unlocking the differential can reduce tire wear and improve driving smoothness.

[0048] Compared with the traditional mechanical transmission system, the multi-speed dual-electric drive axle system provided by the utility model has a higher degree of integration, which not only saves vehicle body space and simplifies the assembly and production process, but also reduces the system's failure points, reduces maintenance costs, and improves overall reliability.

[0049] In summary, compared with the prior art, the multi-speed dual-electric drive axle system provided by the utility model can solve the problem of getting out of trouble on low-adhesion and muddy roads with a lower power transmission system cost. The dual motors can provide higher system power for four-wheel drive heavy trucks, and the multi-speed configuration can ensure that the vehicle is in the high-efficiency zone of the motor at all speeds. It has wider applicability and higher integration. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] In order to more clearly illustrate the technical solution of the embodiment of the utility model, the following is a brief introduction to the drawings required for the description of the embodiment, which constitute a part of the utility model. The schematic embodiment of the utility model and its description explain the utility model and do not constitute an improper limitation of the utility model. In the drawings:

[0051] Figure 1 This is a schematic structural diagram of a multi-speed dual-connected electric drive axle system disclosed in Embodiment 1 of the present utility model;

[0052] Figure 2 This is a schematic structural diagram of a planetary gear train disclosed in Example 1 of the utility model;

[0053] Figure 3 This is a schematic diagram of power flow of the multi-speed dual-connected electric drive axle system disclosed in Embodiment 1 of the utility model when transmitting in the first gear;

[0054] Figure 4 It is a schematic diagram of power flow of the multi-speed dual electric drive axle system disclosed in Embodiment 1 of the utility model during second-speed transmission;

[0055] Figure 5 It is a schematic diagram of power flow of the multi-speed dual electric drive axle system disclosed in Embodiment 1 of the utility model during third-speed transmission;

[0056] Figure 6 It is a schematic diagram of power flow of the multi-speed dual electric drive axle system disclosed in Embodiment 1 of the utility model during fourth-speed transmission;

[0057] Figure 7 This is a schematic diagram of power flow of the multi-speed dual electric drive axle system disclosed in Example 1 of the utility model when the inter-axle differential is locked and enters the first gear transmission.

[0058] Description of reference numerals:

[0059] Four-speed dual-motor electric drive axle 1, motor 11, middle bridge input shaft 12, constant mesh gear 13, first driving gear 14, second driving gear 15, middle bridge left tire 16, middle bridge right tire 17; first driven gear 21, first combined tooth 22, second driven gear 23, second combined tooth 24, first gear hub 25, first shift gear sleeve 26, first shift actuator 27; planetary gear train 3, sun gear 31, planetary gear 32, planet carrier 33, inner gear ring 34, third combined tooth 35, fourth combined tooth 36, second gear hub 37, second shift gear sleeve 38, second shift actuator 39; inter-axle differential 4, first half-axle gear 41, second half-axle gear 42, inter-axle half-axle 43; third driving gear 51, third driven gear 52, middle bridge driving bevel gear 53, middle bridge driven bevel gear 54, middle bridge differential 55; third driving gear dog teeth 61, differential lock sleeve 62, lock sleeve dog teeth 63, spline hub 64, differential lock fork 65, servo cylinder 66; transmission shaft 7; transmission drive axle 8, rear axle input shaft 81, rear axle driving bevel gear 82, rear axle driven bevel gear 83, rear axle differential 84, rear axle left tire 85, rear axle right tire 86. DETAILED DESCRIPTION

[0060] In order to make the purpose, technical solution and advantages of the utility model clearer, the technical solution of the utility model will be clearly and completely described below in combination with the specific embodiments of the utility model and the corresponding drawings. In the description of the utility model, it should be noted that the term "or" is usually used in the sense of including "and / or", unless the content clearly indicates otherwise.

[0061] In the description of the present utility model, it should be noted that, unless otherwise clearly specified and limited, the terms "installed", "connected", and "connected" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or a magnetic connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be internal communication between two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present utility model can be understood according to specific circumstances. In addition, in the description of this application, the terms "first", "second", etc. are only used to distinguish the description and cannot be understood as indicating or implying relative importance.

[0062] Obviously, the described embodiments are only some embodiments of the utility model, not all embodiments. Based on the embodiments of the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0063] Example 1

[0064] refer to Figure 1, Figure 2 The embodiment of the utility model provides a multi-speed dual-connected electric drive axle system, which is preferably suitable for pure electric heavy-duty commercial trucks. It can solve the problem of getting out of trouble on low-adhesion and muddy roads with a lower power transmission system cost, and can ensure that the vehicle is in the high-efficiency zone of the motor at all speeds.

[0065] In a preferred embodiment, the structure of the multi-speed dual-motor electric drive axle system mainly includes: a four-speed dual-motor electric drive axle 1 as a middle axle, a transmission drive axle 8 as a rear axle, an inter-axle differential 4 and a differential lock mechanism; wherein the four-speed dual-motor electric drive axle 1 and the transmission drive axle 8 are connected in series to form a dual-axle structure; the inter-axle differential 4 is arranged between the four-speed dual-motor electric drive axle 1 and the transmission drive axle 8, and the differential lock mechanism is used to lock or unlock the inter-axle differential 4; when the differential lock mechanism is in a locked state, the four-speed dual-motor electric drive axle 1 and the transmission drive axle 8 form an active-active four-wheel drive mode; when the differential lock mechanism is in an unlocked state, there is a speed difference between the four-speed dual-motor electric drive axle 1 and the transmission drive axle 8.

[0066] Specifically, the above-mentioned four-speed dual-motor electric drive bridge 1 serving as the middle bridge refers to a drive bridge located in the middle of the vehicle, which is mainly used to provide and adjust the driving force and transmit the power to the wheels in the middle of the vehicle; the above-mentioned transmission drive bridge 8 serving as the rear bridge is located at the rear of the vehicle, which is mainly used to transmit the power to the wheels at the rear of the vehicle; the middle bridge and the rear bridge are connected in turn through the inter-axle differential 4 and the differential lock mechanism to form a double-bridge structure to achieve different drive modes and flexible power distribution.

[0067] In a preferred embodiment, the four-speed dual-motor electric drive bridge 1 includes dual motors, a first shift mechanism, and a second shift mechanism, wherein the dual motors are used to simultaneously provide power to the system, and the first shift mechanism and the second shift mechanism can achieve torque adjustment and multi-speed shifting by changing their respective meshing transmission relationships, and transmit power to the inter-axle differential 4 assembly, and then the inter-axle differential 4 distributes the power to the middle axle and the rear axle respectively.

[0068] In a preferred embodiment, the dual motors are symmetrically arranged, and the same specifications are selected for both motors. Each motor 11 includes a stator, a coil, a rotor and a rotor shaft, wherein the rotor shaft serves as the intermediate bridge input shaft 12, and can sequentially transmit the torsion generated by the motor 11 to the first shift mechanism, the second shift mechanism and the inter-axle differential 4. In this embodiment, the specific model, structure or specification of the motor 11 is no longer limited, and those skilled in the art can freely select according to actual needs.

[0069] Preferably, the dual motors provide power simultaneously and transmit it to the constant mesh gear 13 meshing therewith through the center bridge input shaft 12. The constant mesh gear 13 meshes with the center bridge input shaft 12 and is simultaneously connected to different gear shaft systems in the first shift mechanism.

[0070] Preferably, the dual motors, the first gear shift mechanism and the second gear shift mechanism are symmetrically deployed on both sides of the center bridge. Although the first gear shift mechanism / the second gear shift mechanism are symmetrically deployed in structure, the structures on both sides work at the same time and should be regarded as a whole mechanism. For ease of understanding, only one side is used as an example for explanation and annotation in the following preferred embodiments and drawings.

[0071] In a preferred embodiment, the first shift mechanism includes two sets of gear shaft systems with different reduction ratios, and each set of gear shaft systems can be selectively connected or not connected to the dual motor transmission. It should be noted that two sets of gear shaft systems with different reduction ratios are provided on both sides of the middle bridge, and the two sets of gear shaft systems provided on both sides have the same structure and specifications. Since the middle bridge input shaft 12 of the dual motor provides power to the first shift mechanisms on both sides at the same time, the motion mode and power flow direction of the first shift mechanisms on both sides are consistent, so in the following embodiments and drawings, only one side of the gear shaft system is used as an example for description.

[0072] Preferably, the first gear shift mechanism includes a first gear shaft system, a second gear shaft system, a first gear hub 25, and a first gear shift actuator 27; wherein, the first gear shaft system is provided with a first driving gear 14 and a first driven gear 21 meshing therewith, and one end of the first driven gear 21 is provided with a first combining tooth 22; the second gear shaft system is provided with a second driving gear 15 and a second driven gear 23 meshing therewith, and one end of the second driven gear 23 is provided with a second combining tooth 24; the first gear hub 25 can be selectively transmission-connected with the first combining tooth 22 or the second combining tooth 24; the first gear hub 25 is used to change the transmission connection relationship of the first gear hub 25.

[0073] Preferably, the reduction ratio of the second driven gear 23 to the second driving gear 15 is smaller than the reduction ratio of the first driven gear 21 to the first driving gear 14. Those skilled in the art should understand that the greater the reduction ratio, the greater the output torque. In this embodiment, the specific ratio of the reduction ratio and the number of teeth of each transmission tooth are not limited, and those skilled in the art can make adaptive adjustments according to actual application scenarios.

[0074] Preferably, the first gear hub 25 is disposed between the first combining teeth 22 and the second combining teeth 24 , and the first gear hub 25 can be selectively drivingly connected with the first combining teeth 22 or the second combining teeth 24 when sliding, so as to change the direction of the power flow.

[0075] Preferably, the first shift actuator 27 sequentially changes the transmission connection relationship of the first gear hub 25 through the first shift fork and the first shift gear sleeve 26. Specifically, when the first shift gear sleeve 26 is connected to the first gear hub 25 and the first coupling tooth 22 at the same time, the power flow is transmitted to the second shift mechanism along the first gear shaft system. At this time, the system is in the first gear transmission, such as Figure 3When the first shifting gear sleeve 26 is connected to the first gear hub 25 and the second coupling gear 24 at the same time, the power flow is transmitted to the second shifting mechanism along the second gear shaft system. At this time, the system is in the second gear transmission, such as Figure 4 .

[0076] In a preferred embodiment, the second shift mechanism includes a planetary gear train 3, a third combined tooth 35, a fourth combined tooth 36, a second gear hub 37 and a second shift actuator 39. It should be noted that a set of second shift mechanisms is provided on each side of the middle bridge, and the second shift mechanisms provided on both sides have the same structure and specifications. Since the motion mode and power flow direction of the second shift mechanisms on both sides are consistent, only the second shift mechanism on one side is used as an example for description in the following embodiments and drawings.

[0077] Preferably, the input end of the second shift mechanism is transmission-connected to the output end of the first shift mechanism, and the output end of the second shift mechanism is transmission-connected to the inter-axle differential 4 .

[0078] like Figure 2 Preferably, the planetary gear train 3 includes a housing, a sun gear 31, planetary gears 32, a planet carrier 33 and an inner ring gear 34. The inner ring gear 34 can be selectively engaged or not engaged with the planet carrier 33 or the housing to change the output torque.

[0079] In a preferred embodiment, the sun gear 31 is arranged in the middle of the planetary gear 32, and the sun gear 31 can mesh with the inner gear ring 34 through the planetary gear 32; the planetary gear 32 is arranged around the sun gear 31, and its inner side meshes with the sun gear 31, and its outer side meshes with the inner gear ring 34, and is connected to the planetary carrier 33 through rollers or bearings. There can be multiple planetary gears 32, which are evenly distributed around the planetary carrier 33; the planetary carrier 33 is a supporting structure connected to the planetary gear 32, and there are multiple holes on the planetary carrier 33, and a planetary gear 32 is installed in each hole to support the planetary gear 32 and ensure its normal movement. By changing the meshing relationship of each component in the planetary gear system 3, its relative operating relationship can be changed to achieve output of different speed ratios and torques, and examples are not listed one by one here.

[0080] Specifically, the specific structure of the planetary gear train 3 can be any embodiment disclosed in the prior art, and its structure is not specifically limited in this patent.

[0081] Preferably, the third combining tooth 35 is connected to the housing, and the fourth combining tooth 36 is connected to the planetary carrier 33; the second gear hub 37 is specifically a gear ring spline hub 64, one end of the second gear hub 37 is connected to the inner gear ring 34, and the other end can be selectively connected to the third combining tooth 35 or the fourth combining tooth 36 to change the direction of power flow.

[0082] Preferably, the second shift actuator 39 sequentially changes the transmission connection relationship of the second gear hub 37 through the second shift fork and the second shift gear sleeve 38. Specifically, when the second shift gear sleeve 38 is connected to the second gear hub 37 and the third coupling tooth 35 at the same time, the inner ring 34 is fixedly connected to the housing. At this time, the power flow is transmitted to the differential along the sun gear 31, the planetary gear 32, and the planetary carrier 33, and the system is in low gear power transmission, such as Figure 3 , Figure 4 When the second shift sleeve 38 is connected to the second gear hub 37 and the fourth coupling gear 36 at the same time, the inner ring gear 34 is connected to the planet carrier 33. At this time, the power flow is transmitted along the sun gear 31 to the planet gear 32, and the system is in high-speed power transmission, and is transmitted to the inter-axle differential 4 through the inner ring gear 34 and the planet carrier 33. Figure 5 , Figure 6 .

[0083] In the first shift mechanism, the first shift actuator 27 can realize the switching of two gears, and in the second shift mechanism, the second shift actuator 39 can realize the switching of high and low gears. This combination can form the switching of four forward gears.

[0084] In a preferred embodiment, the inter-axle differential 4 includes a first half-shaft gear 41, a second half-shaft gear 42 and an inter-axle half-shaft 43, the second half-shaft gear 42 is transmission-connected to the inter-axle half-shaft 43, the first half-shaft gear 41 is used to transfer power to the middle axle, and the second half-shaft gear 42 is used to transfer power to the rear axle.

[0085] In a preferred embodiment, the middle bridge includes a middle bridge left half shaft, a middle bridge left tire 16, a middle bridge right half shaft, a middle bridge right tire 17, a middle bridge differential 55, a middle bridge driving bevel gear 53, a middle bridge driven bevel gear 54, a third driving gear 51 and a third driven gear 52; wherein the third driving gear 51 is transmission-connected to the first half shaft gear 41 of the inter-axle differential 4 and meshes with the third driven gear 52; the middle bridge driving bevel gear 53 is transmission-connected to the third driven gear 52 and meshes with the middle bridge driven bevel gear 54; the input end of the middle bridge differential 55 is transmission-connected to the middle bridge driven bevel gear 54, and the output end of the middle bridge differential 55 is transmission-connected to the middle bridge left tire 16 through the middle bridge left half shaft, and is transmission-connected to the middle bridge right tire 17 through the middle bridge right half shaft, so as to realize the middle bridge diversion.

[0086] In a preferred embodiment, the rear axle includes a rear axle input shaft 81, a rear axle driving bevel gear 82, a rear axle driven bevel gear 83, a rear axle left half shaft, a rear axle left tire 85, a rear axle right half shaft, a rear axle right tire 86 and a rear axle differential 84; wherein, the input end of the rear axle input shaft 81 is connected to the output end of the middle bridge through the transmission shaft 7; the rear axle driving bevel gear 82 is transmission-connected to the rear axle input shaft 81, and meshes with the rear axle driven bevel gear 83; the input end of the rear axle differential 84 is transmission-connected to the rear axle driven bevel gear 83, and the output end of the rear axle differential 84 is transmission-connected to the rear axle left tire 85 through the rear axle left half shaft, and is transmission-connected to the rear axle right tire 86 through the rear axle right half shaft, so as to realize rear axle diversion.

[0087] In a preferred embodiment, the differential lock mechanism is arranged between the inter-axle differential 4 and the transmission shaft 7, and the differential lock mechanism includes a servo cylinder 66, a differential lock fork 65, a spline hub 64, a differential lock sleeve 62, a lock sleeve dog teeth 63, and a third driving gear dog teeth 61; wherein the differential lock sleeve is slidably connected to the spline hub 64, and the servo cylinder 66 drives the sliding of the differential lock sleeve 62 through the differential lock fork 65; a lock sleeve dog teeth 63 are provided at one end of the differential lock sleeve 62, and a third driving gear dog teeth 61 are provided at one end of the third driving gear 51, and when the differential lock sleeve 62 slides on the spline hub 64, the lock sleeve dog teeth 63 can selectively engage with or not engage with the third driving gear dog teeth 61.

[0088] Specifically, when the locking sleeve dog teeth 63 are engaged with the third driving gear dog teeth 61, the inter-axle differential 4, the inter-axle half shaft 43 and the third driving gear 51 are locked as a whole. At this time, the inter-axle differential 4 loses its differential effect, forming an inter-axle differential locking function between the center axle and the rear axle.

[0089] In a preferred embodiment, when the second shift actuator 39 slides the second shift gear sleeve 38 into place through the second shift fork, the second shift gear sleeve 38 is meshed with the second gear hub 37 and the third combination tooth 35 at the same time, the inner gear ring 34 in the planetary gear train 3 is fixedly connected to the housing, and the planetary gear train 3 will reduce the output; at the same time, the first shift actuator 27 slides the first shift gear sleeve 26 into place through the first shift fork, and the first shift gear sleeve 26 is meshed with the first gear hub 25 and the first combination tooth 22 at the same time. At this time, the entire system is in the first gear transmission state, such as Figure 3 , Figure 3 The middle red is the direction of power flow.

[0090] In the first gear transmission state, power is input from the motors 11 on both sides, and then transmitted to the constant mesh gears 13 on both sides by the center bridge input shafts 12 on both sides, and then transmitted to the first driven gear 21 by the first driving gear 14, and then transmitted to the planetary gears 32 through the sun gear 31, and then transmitted to the inter-axle differential 4 by the planetary carrier 33, and finally transmitted through the above-mentioned center bridge shunt and rear axle shunt, so as to realize the power flow transmission of the first gear.

[0091] In a preferred embodiment, the second shifting gear sleeve 38 is kept meshed with the second gear hub 37 and the third combination tooth 35 at the same time, and the inner gear ring 34 in the planetary gear train 3 is fixedly connected to the housing; at the same time, the first shifting actuator 27 slides the first shifting gear sleeve 26 into place, and the first shifting gear sleeve 26 is meshed with the first gear hub 25 and the second combination tooth 24 at the same time. At this time, the whole system is in the second gear transmission state, such as Figure 4 , Figure 4 The middle red is the direction of power flow.

[0092] In the second gear transmission state, power is input from the motors 11 on both sides, and then transmitted to the constant mesh gears 13 on both sides by the middle bridge input shafts 12 on both sides, and then transmitted to the second driven gear 23 by the second driving gear 15, and then transmitted to the planetary gears 32 through the sun gear 31, and then transmitted to the inter-axle differential 4 by the planetary carrier 33, and finally transmitted through the above-mentioned middle bridge shunt and rear axle shunt, so as to realize the power flow transmission of the second gear.

[0093] In a preferred embodiment, when the second shift actuator 39 slides the second shift gear sleeve 38 into place through the second shift fork, the second shift gear sleeve 38 is meshed with the second gear hub 37 and the fourth combination tooth 36 at the same time, the inner gear ring 34 in the planetary gear train 3 is connected to the planet carrier 33, the planetary gear train 3 rotates as a whole, the reduction ratio is 1, and the reduction output is realized; at the same time, the first shift actuator 27 slides the first shift gear sleeve 26 into place through the first shift fork, and the first shift gear sleeve 26 is meshed with the first gear hub 25 and the first combination tooth 22 at the same time. At this time, the whole system is in the third gear transmission state, such as Figure 5 , Figure 5 The middle red is the direction of power flow.

[0094] In the third gear transmission state, power is input from the motors 11 on both sides, and then transmitted to the constant mesh gears 13 on both sides by the middle bridge input shafts 12 on both sides, and then transmitted to the first driven gear 21 by the first driving gear 14, and then transmitted to the planetary gears 32 through the sun gear 31, and transmitted to the inter-axle differential 4 through the inner ring gear 34 and the planetary carrier 33, and finally transmitted through the above-mentioned middle bridge shunt and rear axle shunt, so as to realize the power flow transmission of the third gear.

[0095] In a preferred embodiment, the second shifting gear sleeve 38 is kept meshed with the second gear hub 37 and the fourth combination tooth 36 at the same time, the inner gear ring 34 in the planetary gear train 3 is connected to the planet carrier 33, and the planetary gear train 3 rotates as a whole; at the same time, the first shifting actuator 27 slides the first shifting gear sleeve 26 into place, and the first shifting gear sleeve 26 is meshed with the first gear hub 25 and the second combination tooth 24 at the same time. At this time, the whole system is in the fourth gear transmission state, such as Figure 6 , Figure 6 The middle red is the direction of power flow.

[0096] In the fourth gear transmission state, power is input from the motors 11 on both sides, and then transmitted to the constant mesh gears 13 on both sides by the middle bridge input shafts 12 on both sides, and then transmitted to the second driven gear 23 by the second driving gear 15, and then transmitted to the planetary gears 32 through the sun gear 31, and transmitted to the inter-axle differential 4 through the inner ring gear 34 and the planetary carrier 33, and finally transmitted through the above-mentioned middle bridge shunt and rear axle shunt, so as to realize the power flow transmission of the third gear.

[0097] refer to Figure 7 , where red is the power flow direction. When the vehicle needs to escape from trouble or climb a hill with heavy load, the inter-axle differential is locked and the dual-axle system needs to shift into first gear. The gear shifting process and power flow are as follows:

[0098] The second shift actuator 39 slides the second shift gear sleeve 38 into place through the second shift fork, and the second shift gear sleeve 38 is meshed with the second gear hub 37 and the third combination tooth 35 at the same time, and the inner gear ring 34 in the planetary gear train 3 is fixedly connected to the housing, and the planetary gear train 3 will reduce the output; at the same time, the first shift actuator 27 slides the first shift gear sleeve 26 into place through the first shift fork, and the first shift gear sleeve 26 is meshed with the first gear hub 25 and the first combination tooth 22 at the same time. At this time, the whole system is in the first gear transmission state.

[0099] The servo cylinder 66 slides the differential lock sleeve 62 into place on the spline hub 64 through the differential lock fork 65, so that the lock sleeve dog teeth 63 on the differential lock sleeve 62 engage with the third driving wheel dog teeth. At this time, the inter-axle differential 4, the inter-axle half shaft 43, and the third driving gear 51 are locked as a whole, so that the inter-axle differential 4 loses the differential effect, forming the inter-axle differential locking function of the middle bridge and the rear bridge.

[0100] In the first gear transmission state, power is input from the motors 11 on both sides, and then transmitted to the constant mesh gears 13 on both sides by the middle bridge input shafts 12 on both sides, and then transmitted to the first driven gear 21 by the first driving gear 14, and then transmitted to the planetary gears 32 through the sun gear 31, and then transmitted to the inter-axle differential 4 by the planetary carrier 33. At this time, the inter-axle differential 4, the inter-axle half shafts 43, and the third driving gear 51 are locked as a whole, and finally, through the above-mentioned middle bridge shunt and rear axle shunt, the power flow transmission of the first gear in the locked state of the inter-axle differential 4 is realized.

[0101] Compared with the prior art, this embodiment adopts a double-bridge structure in which a four-speed dual-motor electric drive bridge 1 and a transmission drive bridge 8 are connected in series, and the use of an inter-axle differential 4 and a differential lock mechanism enables the system to maintain high stability and reliability under different working conditions; when the differential lock mechanism is in a locked state, the system forms an active-active four-wheel drive mode, ensuring traction and passability under complex road conditions, and improving the stability and reliability of the vehicle.

[0102] Furthermore, the multi-speed configuration can provide efficient power transmission, reduce energy loss, and improve the energy efficiency of the entire system, which not only helps to extend the battery life, but also reduces the vehicle's energy consumption costs.

[0103] Thanks to the dual-motor system, the multi-speed dual-electric drive axle system provided in this embodiment can provide higher system power to meet the power requirements of heavy trucks to improve overall performance; the lockable and unlockable design of the differential lock mechanism enables the vehicle to be flexibly adjusted according to actual road conditions; on low adhesion or muddy roads, the locking differential can provide greater traction to help the vehicle get out of trouble; and on ordinary roads, unlocking the differential can reduce tire wear and improve driving smoothness.

[0104] Example 2

[0105] The present embodiment provides a vehicle, preferably a heavy-duty commercial truck with pure electric drive, including the multi-speed dual-axle electric drive axle system described in the above-mentioned embodiment 1. The technical features already recorded in the above-mentioned embodiment 1 are naturally inherited in the present embodiment; specifically, in the present embodiment, a multi-speed dual-axle electric drive axle system is configured with the same functions as those in the above-mentioned embodiment 1, and therefore they will not be described one by one.

[0106] Although example embodiments have been described herein with reference to the accompanying drawings, it should be understood that the above example embodiments are merely exemplary and are not intended to limit the scope of the present application to this. Those of ordinary skill in the art may make various changes and modifications therein without departing from the scope and spirit of the present application. All these changes and modifications are intended to be included within the scope of the present application as required by the appended claims.

[0107] 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.

[0108] Similarly, it should be understood that in order to streamline the present application and help understand 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, the method of the present application should not be interpreted as reflecting the following intention: the claimed application requires more features than the features clearly stated in each claim. More specifically, as reflected in the corresponding claims, its utility model point is that the corresponding technical problem can be solved with less than all the features of a single disclosed embodiment. Therefore, the claims following the specific embodiment are hereby explicitly incorporated into the specific embodiment, wherein each claim itself serves as a separate embodiment of the present application.

[0109] It will be understood by those skilled in the art that, except for mutually exclusive features, all features disclosed in this specification (including the accompanying claims, abstracts and drawings) and all processes or units of any method or device disclosed in this specification may be combined in any combination. Unless otherwise expressly stated, each feature disclosed in this specification (including the accompanying claims, abstracts and drawings) may be replaced by an alternative feature that provides the same, equivalent or similar purpose.

Claims

1. A multi-speed dual-connected electric drive axle system, characterized in that: It includes a four-speed dual-motor electric drive axle, a transmission drive axle, an inter-axle differential, and a differential lock mechanism; The four-speed dual-motor electric drive axle is drivingly connected to the transmission drive axle; The inter-axle differential and the differential lock mechanism are arranged between the four-speed dual-motor electric drive axle and the transmission drive axle; The differential lock mechanism is used to lock or unlock the inter-axle differential. When the differential lock mechanism is in an unlocked state, there is a speed difference between the four-speed dual-motor electric drive axle and the transmission drive axle.

2. The multi-speed dual-connected electric drive axle system according to claim 1, characterized in that: The four-speed dual-motor electric drive bridge includes dual motors, a first shift mechanism, and a second shift mechanism; The dual motors, the first shift mechanism and the second shift mechanism are all symmetrically arranged, and the dual motors are connected to the inter-axle differential through the first shift mechanism and the second shift mechanism in sequence; The first shift mechanism comprises two sets of gear shaft systems with different reduction ratios, and each set of the gear shaft systems can be selectively connected or disconnected with the dual motor transmission; The second shift mechanism includes a planetary gear train, and an inner gear ring in the planetary gear train can be selectively engaged or not engaged with a planet carrier or a housing.

3. The multi-speed dual-connected electric drive axle system according to claim 2, characterized in that: The first shifting mechanism comprises: - a first gear shaft system, comprising a first driving gear and a first driven gear meshing therewith, wherein one end of the first driven gear is provided with a first coupling tooth; - a second gear shaft system, comprising a second driving gear and a second driven gear meshing therewith, wherein one end of the second driven gear is provided with a second coupling tooth; a reduction ratio between the second driven gear and the second driving gear is smaller than a reduction ratio between the first driven gear and the first driving gear; - a first gear hub, selectively connected to the first coupling tooth or the second coupling tooth in driving connection; - A first gear shift actuator, used to change the transmission connection relationship of the first gear hub.

4. The multi-speed dual-connected electric drive axle system according to claim 2, characterized in that: The second shifting mechanism comprises: - the planetary gear train comprises a housing, a sun gear, planetary gears, the planet carrier and the inner gear ring; - a third coupling tooth connected to the housing; - a fourth coupling tooth connected to the planet carrier; - a second gear hub, one end of which is connected to the inner gear ring, and the other end of which can be selectively drivingly connected to the third combining tooth or the fourth combining tooth; - A second gear shift actuator, used to change the transmission connection relationship of the second gear hub.

5. The multi-speed dual-connected electric drive axle system according to claim 2, characterized in that: The input end of the second shift mechanism is drivingly connected to the output end of the first shift mechanism, and the output end of the second shift mechanism is drivingly connected to the inter-axle differential.

6. The multi-speed dual-connected electric drive axle system according to claim 1, characterized in that: The inter-axle differential comprises a first half-axle gear, a second half-axle gear and an inter-axle half-axle, wherein the second half-axle gear is drivingly connected to the inter-axle half-axle; The first half-shaft gear is used to transmit power to the four-speed dual-motor electric drive axle; The second side gear is used to transmit power to the transmission drive axle.

7. The multi-speed dual-connected electric drive axle system according to claim 6, characterized in that: The four-speed dual-motor electric drive axle is configured as a middle axle, and the middle axle also includes a middle axle left tire, a middle axle right tire, a middle axle differential, a middle axle driving bevel gear, a middle axle driven bevel gear, a third driving gear and a third driven gear; The third driving gear is drivingly connected to the first axle gear and meshes with the third driven gear; The middle bridge driving bevel gear is transmission-connected with the third driven gear and meshes with the middle bridge driven bevel gear; The input end of the middle bridge differential is drivingly connected to the middle bridge driven bevel gear, and the output end of the middle bridge differential is drivingly connected to the middle bridge left tire and the middle bridge right tire respectively.

8. The multi-speed dual-connected electric drive axle system according to claim 7, characterized in that: The transmission drive axle is configured as a rear axle, and the rear axle further includes a rear axle input shaft, a rear axle driving bevel gear, a rear axle driven bevel gear, a rear axle left tire, a rear axle right tire and a rear axle differential; The input end of the rear axle input shaft is connected to the output end of the middle axle through a transmission shaft; The rear axle driving bevel gear is drivingly connected to the rear axle input shaft and meshes with the rear axle driven bevel gear; The input end of the rear axle differential is drivingly connected to the rear axle driven bevel gear, and the output end of the rear axle differential is drivingly connected to the rear axle left tire and the rear axle right tire respectively.

9. The multi-speed dual-connected electric drive axle system according to claim 8, characterized in that: The differential lock mechanism is arranged between the transmission shaft and the inter-axle differential, and the differential lock mechanism comprises a servo cylinder, a differential lock fork, a spline hub, a differential lock sleeve, lock sleeve dog teeth, and a third driving gear dog teeth; The differential lock sleeve is slidably connected to the spline hub, and the servo cylinder drives the differential lock sleeve to slide through the differential lock fork; One end of the differential lock sleeve is provided with lock sleeve dog teeth, and one end of the third driving gear is provided with third driving gear dog teeth. When the differential lock sleeve slides on the spline hub, the lock sleeve dog teeth can selectively engage or not engage with the third driving gear dog teeth.

10. A vehicle, characterized in that: It comprises a multi-speed dual electric drive axle system as described in any one of claims 1 to 9.

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