Dual-motor independent driving synchronous gear shifting two-gear transmission system and electric vehicle

Abstract

The application discloses a double-motor independent driving synchronous gear shifting two-gear transmission system, which is mainly composed of a first driving motor, a second driving motor, a first planetary gear train, a second planetary gear train, a first controllable bidirectional clutch, a gear shifting execution mechanism, a reverse gear execution mechanism, a third planetary gear train, a fourth planetary gear train, a second controllable bidirectional clutch, a first transmission housing, a second transmission housing, a left half axle, a right half axle, a left axle housing, a right axle housing, a left half axle sleeve, a right half axle sleeve, a left wheel hub and a right wheel hub. The application also discloses an electric vehicle, which adopts distributed driving to realize independent control of left and right wheel torques, and is provided with two gears to meet the dual demands of the electric vehicle on power performance and economic performance, and is provided with left and right wheel synchronous gear shifting functions to improve vehicle driving stability and safety, and in addition, the reverse gear function can be realized without adding other clutches, and in addition, the other side centralized driving can be realized when single side motor fault occurs, and the functional safety is improved.

Description

Technical Field

[0001] This invention belongs to the field of electric vehicles, and specifically relates to a dual-motor independent drive synchronous shifting two-speed transmission system and vehicle. Background Technology

[0002] With the increasing scarcity of oil resources and growing environmental pollution, the concept of low-carbon and environmentally friendly practices has gained widespread acceptance. Traditional gasoline-powered vehicles, heavily reliant on oil resources and emitting significant carbon emissions, are no longer suitable for today's energy conservation and emission reduction needs, necessitating a transformation and upgrade of the automotive industry. Meanwhile, pure electric vehicles, with their zero emissions, low noise, and high energy conversion efficiency, have become the future trend of automotive development. In recent years, the production and sales of electric vehicles have continued to grow, and the huge market demand has driven the development of related technologies. In particular, the current widespread problem of relatively short driving range in electric vehicles places higher demands on their energy efficiency. Therefore, the design of efficient drive systems for electric vehicles has become a hot research topic.

[0003] Electric vehicles can be categorized into two types based on how the motor drives the wheels: centralized drive and independent drive. Compared to centralized drive electric vehicles, independent drive electric vehicles have gained widespread attention due to their advantages such as independently controllable torque for each wheel and a high degree of system integration. Properly distributing the torque between the left and right wheels of an independent drive electric vehicle not only allows for direct yaw control, improving vehicle handling and stability, but also enhances the efficiency of the electric drive system and reduces tire slippage losses. Currently, independent electric drive systems can be broadly classified into two types: dual-motor centralized opposed independent drive electric drive axles and hub / wheel-side distributed independent drive electric drive systems. Hub / wheel-side distributed independent drive electric drive systems place the drive motor inside / near the wheel to directly drive it, omitting components such as universal joints, differentials, and half-shafts. This results in advantages such as small size, high power-to-weight ratio, and high transmission efficiency. However, it also increases unsprung mass, reducing the driving stability and ride comfort of the electric vehicle, and increasing reliability issues caused by motor vibration and water immersion. The dual-motor centralized opposed independent drive electric drive axle arranges two drive motors and two reducers symmetrically on the frame, connecting them to the wheels via traditional half-shafts. It independently drives the wheels on both sides, not only achieving independent control of the torque of the left and right wheels, but also retaining the original chassis structure. It has good process inheritance while avoiding the harm caused by the increase in unsprung mass, and has broad development prospects.

[0004] Because electric motors have a wide speed range, current electric vehicles often use a direct-drive solution with a motor and a reducer. However, a fixed speed ratio is difficult to meet both the requirements of power and economy, and the motor also struggles to consistently operate within its efficient range under complex conditions. To address this issue, automakers have begun incorporating two-speed transmissions into the electric drive axle. Compared to a direct-drive solution with a single motor and reducer, the use of a two-speed transmission not only reduces the requirements for the motor, decreasing its size and cost, but also allows the motor to operate within its efficient range as much as possible through optimization of the two-speed ratio, thereby improving vehicle economy and increasing driving range.

[0005] For independently driven electric vehicles, to take advantage of the performance enhancements offered by a two-speed transmission, a two-speed transmission system needs to be installed on each side, as the left and right motors are driven independently. During gear shifts, differences in driving conditions on both sides of the vehicle, inconsistent response speeds due to internal factors in the shift actuators on both sides, or a direct failure of one shift actuator can all lead to asynchronous gear shifts on both sides. This results in asymmetrical torque between the left and right wheels, causing sudden changes in lateral and longitudinal acceleration, reducing vehicle stability, and even affecting driving safety. However, current research on the synchronous shifting problem of dual-motor independently driven two-speed transmission systems is scarce. Generally, only corresponding compensation control strategies can be used to reduce vehicle yaw caused by asynchronous shifting, which greatly increases the difficulty of shift control. Furthermore, to improve the functional safety of the system, the problem of single-motor failure in the dual-motor independently driven two-speed transmission system should also be considered, ensuring that the vehicle can still maintain normal operation even when one motor cannot provide torque. Summary of the Invention

[0006] This invention designs and develops a dual-motor independent drive synchronous shifting two-speed transmission system. It employs an internal rotor motor on each side as a power source and incorporates two planetary gear sets for speed reduction and torque amplification. The purpose of this invention is to achieve synchronous gear switching between the left and right sides via a coupling sleeve and two controllable bidirectional clutches, thus balancing the dual demands of electric vehicles for power and economy, while also improving vehicle stability and safety. In addition to synchronous shifting, this dual-motor independent drive synchronous shifting two-speed transmission system also provides a reverse gear function and a safety redundancy function in case of single-motor failure.

[0007] The technical solution provided by this invention is as follows:

[0008] A dual-motor independent drive synchronous shifting two-speed transmission system, including:

[0009] Transmission housing;

[0010] First drive motor housing;

[0011] The first inner rotor is rotatably supported on both sides of the center of the first drive motor housing;

[0012] The first motor shaft is a hollow shaft and is fixedly connected to the first inner rotor;

[0013] The left half-shaft is rotatably supported at the center of the first motor shaft;

[0014] The first sun gear is fixedly connected to the output end of the first motor shaft;

[0015] Multiple first planetary gears, which mesh and match with the first sun gear;

[0016] The first internal gear ring meshes with the first planetary gear, and the first internal gear ring is fixedly connected to the first drive motor housing.

[0017] The first planetary carrier has a hollow shaft and is rotatably supported on the left half-shaft;

[0018] A first planetary carrier cover is rotatably supported on the first motor shaft, and the first planetary carrier cover is fixedly connected to the first planetary carrier for rotatably supporting the plurality of first planetary gears;

[0019] The second sun gear is fixedly connected to the first planet carrier;

[0020] Multiple second planetary gears that mesh with the second sun gear;

[0021] The second internal gear ring meshes with the second planetary gear, and the second internal gear ring is provided with a first stepped hollow shaft and is rotatably supported on the left half shaft. The first stepped hollow shaft is provided with a first spline and a first engaging gear ring.

[0022] The second planetary carrier is splinedly connected to the left half-shaft;

[0023] The second planetary carrier cover is rotatably supported on the first planetary carrier, and the second planetary carrier cover is fixedly connected to the second planetary carrier for rotatably supporting the plurality of second planetary gears;

[0024] The outer ring of the first controllable bidirectional clutch is fixedly connected to the transmission housing;

[0025] The inner ring of the first controllable bidirectional clutch is fixedly connected to the second inner gear ring via the first spline.

[0026] Multiple first forward pawls;

[0027] A plurality of first reverse pawls are mounted in pairs with the plurality of first forward pawls between the outer ring of the first controllable bidirectional clutch and the inner ring of the first controllable bidirectional clutch;

[0028] A plurality of first forward pawl springs are mounted between the plurality of first forward pawls and the outer ring of the first controllable bidirectional clutch;

[0029] A plurality of first reverse gear pawl springs are mounted between the plurality of first reverse gear pawls and the outer ring of the first controllable bidirectional clutch;

[0030] A first control disc has a plurality of protruding first pawls evenly distributed on its side surface. The plurality of first pawls are inserted between the outer ring of the first controllable bidirectional clutch and the plurality of first reverse gear pawls. A toothed sector is provided on the outer circumference of the first control disc.

[0031] Reverse gear motor housing, which is fixedly connected to the transmission housing;

[0032] The reverse gear motor shaft is rotatably supported on the transmission housing;

[0033] The first reverse gear meshes with the first control disk gear sector to drive the first control disk to rotate, and the first reverse gear is splinedly connected to the reverse motor shaft;

[0034] The first splined hub is splinedly connected to the left half-shaft.

[0035] The first engaging sleeve slides on the first splined hub, and the first engaging sleeve is provided with an annular groove;

[0036] A two-way lead screw with symmetrical reverse threads on its left and right sides, the two-way lead screw being rotatably supported on the outer ring of the controllable two-way clutch;

[0037] The first shift fork has its upper part threaded into one end of the bidirectional lead screw, and its lower part inserted into the annular groove of the first engagement sleeve.

[0038] A shift motor housing, which is fixedly connected to the transmission housing;

[0039] The shift motor shaft is rotatably supported on the transmission housing;

[0040] The first shift gear is splinedly connected to the shift motor shaft.

[0041] The second shift gear meshes with the first shift gear, and the second shift gear is fixedly connected to the center of symmetry of the bidirectional lead screw;

[0042] Second drive motor housing;

[0043] The second inner rotor is rotatably supported on both sides of the center of the second drive motor housing;

[0044] The second motor shaft is a hollow shaft and is fixedly connected to the second inner rotor;

[0045] The right half-shaft is rotatably supported at the center of the second motor shaft;

[0046] The third sun gear is fixedly connected to the output end of the second motor shaft;

[0047] Multiple third planetary gears, which mesh and match with the third sun gear;

[0048] The third internal gear ring meshes with the third planetary gear, and the third internal gear ring is fixedly connected to the second drive motor housing;

[0049] The third planetary carrier has a hollow shaft and is rotatably supported on the right half-shaft;

[0050] The third planetary carrier cover is rotatably supported on the second motor shaft, and the third planetary carrier cover is fixedly connected to the third planetary carrier for rotatably supporting the plurality of third planetary gears;

[0051] The fourth sun gear is fixedly connected to the third planet carrier;

[0052] Multiple fourth planetary gears, which mesh and match with the fourth sun gear;

[0053] The fourth internal gear ring meshes with the fourth planetary gear, and the fourth internal gear ring is provided with a second stepped hollow shaft and is rotatably supported on the right half shaft. The second stepped hollow shaft is provided with a second spline and a second engaging gear ring.

[0054] The fourth planetary carrier is splinedly connected to the right half-shaft;

[0055] A fourth planetary carrier cover, which is rotatably supported on the third planetary carrier and is fixedly connected to the fourth planetary carrier, is used to rotatably support the plurality of fourth planetary gears;

[0056] The first planetary array and the third planetary array have identical structural parameters, and the second planetary array and the fourth planetary array have identical structural parameters.

[0057] The outer ring of the second controllable bidirectional clutch is fixedly connected to the transmission housing;

[0058] The inner ring of the second controllable bidirectional clutch is fixedly connected to the fourth internal gear ring via the second spline.

[0059] Multiple second forward pawls;

[0060] Multiple second reverse pawls are mounted in pairs with the multiple second forward pawls between the outer ring of the second controllable bidirectional clutch and the inner ring of the second controllable bidirectional clutch;

[0061] A plurality of second forward pawl springs are mounted between the plurality of second forward pawls and the outer ring of the second controllable bidirectional clutch;

[0062] A plurality of second reverse gear pawl springs are mounted between the plurality of second reverse gear pawls and the outer ring of the second controllable bidirectional clutch;

[0063] The second control disc has a plurality of protruding second pawls evenly distributed on its side surface. The plurality of second pawls are inserted between the outer ring of the second controllable bidirectional clutch and the plurality of second reverse gear pawls. The outer circumference of the second control disc is provided with a toothed sector.

[0064] The second reverse gear meshes with the gear sector of the second control disk to drive the second control disk to rotate. The second reverse gear is splinedly connected to the reverse motor shaft, and the second reverse gear and the first reverse gear are symmetrically arranged on both sides of the reverse motor shaft.

[0065] The second splined hub is connected to the splined right half-shaft.

[0066] The second engaging sleeve slides on the second splined hub, and the second engaging sleeve is provided with an annular groove;

[0067] The second shift fork has its upper part threadedly engaged with the other end of the bidirectional lead screw, and its lower part inserted into the annular groove of the second engagement sleeve. The second shift fork and the first shift fork are symmetrically arranged on both sides of the bidirectional lead screw.

[0068] A centrally driven engagement gear ring is connected to the right half-shaft via a spline.

[0069] Preferably, the first engagement gear ring and the centralized drive engagement gear ring are symmetrically arranged on both sides of the first spline hub; the distance between the second engagement gear ring and the right end face of the second spline hub is the same as the distance between the first engagement gear ring and the left end face of the first spline hub; the length of the second spline hub should satisfy that when the first engagement sleeve connects the first spline hub and the centralized drive engagement gear ring, the second engagement sleeve always slides only on the second spline hub; the thread lengths on the left and right sides of the bidirectional lead screw should satisfy that when the first engagement sleeve and the second engagement sleeve move to the left and right respectively, the first engagement sleeve and the second engagement sleeve can respectively mesh with the first engagement gear ring and the second engagement gear ring, and when the first engagement sleeve and the second engagement sleeve move synchronously to the middle, the first engagement sleeve can mesh with the centralized drive engagement gear ring, but the first engagement sleeve and the second engagement sleeve will not collide with the second shift gear.

[0070] Preferably, it also includes:

[0071] The left axle housing is fixedly connected to the first drive motor housing;

[0072] The right axle housing is fixedly connected to the second drive motor housing;

[0073] The left half-shaft sleeve is fixedly connected to the left axle housing;

[0074] The right half-shaft sleeve is fixedly connected to the right axle housing;

[0075] The left wheel hub is fixedly connected to the outer end flange of the left half-shaft;

[0076] The right wheel hub is fixedly connected to the outer end flange of the right half-shaft;

[0077] The left wheel rim is fixedly connected to the left wheel hub;

[0078] The right wheel rim is fixedly connected to the right wheel hub.

[0079] Preferably, it also includes:

[0080] The first stator is fixedly connected to the housing of the first drive motor.

[0081] The second stator is fixedly connected to the housing of the second drive motor.

[0082] Preferably, the first drive motor housing includes a first drive motor main housing and a first drive motor housing cover, and the first drive motor main housing and the first drive motor housing cover are fixedly connected to form a closed cavity for accommodating the first stator and the first inner rotor;

[0083] The second drive motor housing includes a second drive motor main housing and a second drive motor housing cover. The second drive motor main housing and the second drive motor housing cover are fixedly connected to form a closed cavity for accommodating the second stator and the second inner rotor.

[0084] Preferably, the transmission housing includes a first transmission housing and a second transmission housing, the first transmission housing and the second transmission housing are fixedly connected, the first transmission housing and the first drive motor housing are fixedly connected, and are used to house the first planetary gear set, the second planetary gear set and the first controllable bidirectional clutch; the second transmission housing and the second drive motor housing are fixedly connected, and are used to house the first splined hub, the first engagement sleeve, the bidirectional lead screw, the first shift fork, the second splined hub, the second engagement sleeve, the second shift fork, the centralized drive engagement gear ring, the third planetary gear set, the fourth planetary gear set and the second controllable bidirectional clutch, etc.

[0085] Preferably, the first sun gear is axially limited by a retaining circlip at the end of the first motor shaft;

[0086] The second sun gear is axially limited by the end retaining circlip of the first planet carrier;

[0087] The second planetary carrier is axially limited by a snap ring on the stepped shaft of the left half-shaft;

[0088] The first splined hub is axially limited by the shaft end retaining spring of the left half shaft;

[0089] The centralized drive engagement gear ring is axially limited by the shaft end retaining ring of the right half shaft.

[0090] The second splined hub is axially limited by the protrusion formed on the end face of the centralized drive engagement gear ring;

[0091] The third sun gear is axially limited by the circlip at the end of the second motor shaft;

[0092] The fourth sun gear is axially limited by the end retaining circlip of the third planet carrier;

[0093] The fourth planetary carrier is axially limited by a snap ring on the stepped shaft of the right half-shaft.

[0094] Preferably, the first planetary gear has a circular hole at its center;

[0095] The first planetary carrier has a radial circular hole;

[0096] The first planetary carrier cover has a radial cylindrical shaft;

[0097] Wherein, the radial cylindrical shaft of the first planetary carrier cover and the first planetary carrier are matched and installed with the circular holes of the first planetary gear;

[0098] The second planetary gear has a circular hole at its center;

[0099] The second planetary carrier has a radial circular hole;

[0100] The second planetary carrier cover has a radial cylindrical shaft;

[0101] The radial cylindrical shaft of the second planetary carrier cover and the second planetary carrier are matched and installed with the circular holes of the second planetary gears;

[0102] The third planetary gear has a circular hole at its center;

[0103] The third planetary carrier has radial circular holes;

[0104] The third planetary carrier cover has a radial cylindrical shaft;

[0105] The radial cylindrical shaft of the third planetary carrier cover and the third planetary carrier are matched and installed with the circular holes of the third planetary gear;

[0106] The fourth planetary gear has a circular hole at its center;

[0107] The fourth planetary carrier has a radial circular hole;

[0108] The fourth planetary carrier cover has a radial cylindrical shaft;

[0109] The radial cylindrical shaft of the fourth planetary carrier cover and the fourth planetary carrier are matched and installed with the circular holes of the fourth planetary gear.

[0110] An electric vehicle uses the aforementioned dual-motor independent drive synchronous shifting two-speed transmission system.

[0111] Compared with the prior art, the beneficial effects of this invention are:

[0112] 1. The dual-motor independent drive synchronous shifting two-speed transmission system provided by this invention, compared with the existing distributed two-speed transmission system, can achieve accurate synchronous shifting of the two transmissions, avoiding sudden changes in vehicle lateral and longitudinal acceleration caused by the asynchrony of the independent shifting control of the left and right transmissions, thus improving the stability and safety of vehicle driving. Furthermore, the use of a coupling sleeve for shifting between high and low gears results in a simple structure, mature technology, and low manufacturing cost.

[0113] 2. The dual-motor independent drive synchronous shifting two-speed transmission system provided by this invention, in addition to its shifting function, also functions as a vehicle drive mode switching device. By controlling the reverse gear actuator to change the locking direction of the first and second controllable bidirectional clutches, and by controlling the shifting actuator to change the rotation direction of the bidirectional lead screw, the dual-motor independent drive synchronous shifting two-speed transmission system can switch between four operating modes, specifically including forward first gear, forward second gear, reverse gear, and centralized drive mode. In particular, the centralized drive mode allows the vehicle to switch from dual-motor independent drive to centralized drive by the single, undamaged motor in the event of a single motor failure, greatly improving system functional safety.

[0114] 3. The dual-motor independent drive synchronous shifting two-speed transmission system provided by the present invention uses a controllable bidirectional clutch, which can lock the planetary gear ring in a bidirectional controllable manner as needed without adding other shifting mechanisms, greatly simplifying the first and second gear switching control; in addition, by switching the working mode of the controllable bidirectional clutch, it can transmit reverse torque, thereby realizing the vehicle reverse gear without adding other mechanisms, further reducing the overall size of the transmission and simplifying the transmission structure and actuator cost.

[0115] 4. The dual-motor independent drive synchronous shifting two-speed transmission system provided by this invention offers a variety of operating modes, catering to different power and fuel economy requirements at varying vehicle speeds. Furthermore, the dual motors are coaxially arranged, resulting in a compact and rational layout with high integration, facilitating installation within the vehicle. Additionally, the two controllable bidirectional clutches share a single actuator, and the shifting of both gearboxes shares another actuator, reducing the number of components. The entire system achieves all functions using only two sets of actuators, resulting in a simple structure and high integration. Attached Figure Description

[0116] Figure 1 This is a mechanical structure diagram of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention.

[0117] Figure 2 This is a simplified structural diagram of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention.

[0118] Figure 3 This is a schematic diagram of the mechanical structure of the controllable bidirectional clutch of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention in neutral and second gear.

[0119] Figure 4 This is a schematic diagram of the mechanical structure of the controllable bidirectional clutch in the first gear state of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention.

[0120] Figure 5This is a schematic diagram of the mechanical structure of the controllable bidirectional clutch in reverse gear of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention.

[0121] Figure 6 This is a schematic diagram of the power transmission route of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention when it is in forward gear.

[0122] Figure 7 This is a schematic diagram of the power transmission route of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention when it is in forward second gear.

[0123] Figure 8 This is a schematic diagram of the power transmission route when the first drive motor of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention fails.

[0124] Figure 9 This is a schematic diagram of the power transmission route when the second drive motor of the dual-motor independent drive synchronous shifting two-speed transmission system described in this invention fails. Detailed Implementation

[0125] The present invention will now be described in further detail with reference to the accompanying drawings, so that those skilled in the art can implement it based on the description.

[0126] like Figure 1 As shown, this invention provides a dual-motor independent drive synchronous shifting two-speed transmission system. This system has an internal rotor motor on each side as a power source, and each side is equipped with two planetary gear sets for speed reduction and torque amplification. Gear switching between the left and right sides is synchronized via a coupling sleeve and two controllable bidirectional clutches, balancing the dual requirements of power and economy for electric vehicles while improving vehicle stability and safety. In addition to synchronous shifting, this dual-motor independent drive synchronous shifting two-speed transmission system also provides a reverse gear function and a safety redundancy function in case of single-motor failure.

[0127] The dual-motor independent drive synchronous shifting two-speed transmission system provided by this invention mainly consists of a first drive motor 100, a second drive motor 200, a first planetary gear train 300, a second planetary gear train 400, a first controllable bidirectional clutch 500, a shifting actuator 600, a reverse gear actuator 700, a third planetary gear train 800, a fourth planetary gear train 900, a second controllable bidirectional clutch 1000, a first transmission housing 121, a second transmission housing 123, a left half-shaft 112, a right half-shaft 212, a left axle housing 109, a right axle housing 209, a left wheel rim 118, a right wheel rim 218, a left half-shaft sleeve 111, a right half-shaft sleeve 211, a left wheel hub 116, and a right wheel hub 216.

[0128] The first drive motor 100 includes a left side housing 101, a first stator 102, a right side housing 103, a bearing 104, a bearing 2, a first motor shaft 106, and a first inner rotor 107.

[0129] The first stator 102 is fixedly installed in the end face annular groove between the left housing 101 and the right housing 103 of the first drive motor, and the three are fixedly connected as one unit. The left housing 101 and the right housing 103 of the first drive motor support the first motor shaft 106 through bearing 104 and bearing 205 respectively. The first inner rotor 107 is connected to the first motor shaft 106 through a spline. Bearing 104 is axially limited by the first inner rotor 107, the first inner rotor 107 is axially limited by bearing 205, and bearing 205 is axially limited by the right housing 103 of the first drive motor.

[0130] The first planetary gear train 300 is a single-row, single-stage planetary gear train, including the first planetary gear 301, the first sun gear 302, the first planetary carrier 303, the first planetary carrier cover 304, the No. 3 bearing 305, the No. 1 needle roller bearing 306, the first internal gear ring 307, the first internal gear ring screw 308, and the first retaining ring 309.

[0131] The first sun gear 302 is splinedly connected to the first motor shaft 106, and the first sun gear 302 is axially limited by the first snap ring 309 at the end of the first motor shaft 106; the first planetary carrier cover 304 has a radial cylindrical shaft that extends into the circular holes of the first planet gear 301 and the first planetary carrier 303 and can rotate freely; the first planetary carrier 303 and the first planetary carrier cover 304 are fixedly connected by multiple fastening screws; the first planetary carrier cover 304 is supported on the first motor shaft 106 by bearing No. 3 305, and bearing No. 3 305 is axially limited by the shoulder of the first motor shaft 106; the first planetary carrier 303 extends to the right to form a stepped hollow shaft, and the hollow shaft of the first planetary carrier 303 is supported on the left half shaft 112 by needle roller bearing No. 1; the first internal gear ring 307 is fixedly connected to the right side housing 103 of the first drive motor by first internal gear ring screw 308;

[0132] In this embodiment, as a preferred embodiment, the planetary gear set characteristic parameter of the first planetary gear train 300 is greater than 1. The planetary gear set characteristic parameter is a commonly defined parameter in the mechanical field, which refers to the ratio of the number of teeth of the internal gear ring to the number of teeth of the sun gear in the planetary gear train.

[0133] The second planetary gear train 400 is a single-row, single-stage planetary gear train, including the second planetary gear 401, the second sun gear 402, the second planetary carrier 403, the second planetary carrier cover 404, the No. 4 bearing 405, the second internal gear ring 406, the second snap ring 407, the third snap ring 408, and the No. 5 bearing 409.

[0134] The second sun gear 402 is splinedly connected to the hollow shaft of the first planetary carrier 303, and the second sun gear 402 is axially limited by a second retaining ring 407 at the hollow shaft end of the first planetary carrier 303. The second planetary carrier cover 404 has a radial cylindrical shaft that extends into the circular holes of the second planet gear 401 and the second planetary carrier 403 and can rotate freely. The second planetary carrier 403 and the second planetary carrier cover 404 are fixedly connected by multiple fastening screws. The second planetary carrier cover 404 is supported by a bearing 405 on the first planetary carrier 303. On the 03, the No. 4 bearing 405 is axially limited by the shoulder of the hollow shaft of the first planetary carrier 303; the second planetary carrier 403 is connected to the stepped shaft spline of the left half shaft 112, and is axially limited by the third snap ring 408 on the stepped shaft of the left half shaft 112; the second internal gear ring 406 extends to the right to form a stepped hollow shaft, and the stepped hollow shaft of the second internal gear ring 406 is provided with a first spline 406a and a first engaging gear ring 406b, and the second internal gear ring 406 is supported on the left half shaft 112 by the No. 5 bearing 409;

[0135] In this embodiment, as a preferred embodiment, the planetary gear characteristic parameter of the second planetary gear train 400 is greater than 1.

[0136] like Figure 1 and Figure 3 As shown, the first controllable bidirectional clutch 500 is located on the right side of the second planetary gear train 400, and includes the first controllable bidirectional clutch outer ring 501, the first controllable bidirectional clutch inner ring 502, the first forward pawl 503, the first reverse pawl 504, the first forward pawl spring 505, the first reverse pawl spring 506, the first control plate 507, the first gear sector 508, the first gear sector screw 509, the fourth retaining ring 510, the fifth retaining ring 511, the first outer ring screw 512, and the sixth retaining ring 513;

[0137] The inner ring 502 of the first controllable bidirectional clutch is connected to the second internal gear ring 406 via a first spline 406a and is axially limited by a sixth retaining ring 513 on the first spline 406a. The outer ring 501 of the first controllable bidirectional clutch has paired grooves and is fixedly connected to the first transmission housing 121 via a first outer ring screw 512. A first forward pawl 503 and a first reverse pawl 504 are installed in pairs in the grooves of the outer ring 501 of the first controllable bidirectional clutch and are freely rotatable. They are axially limited by a fifth retaining ring 511 on the outer ring 501 of the first controllable bidirectional clutch. When the first forward pawl 503 and the first reverse pawl 504 fall, they can engage with the first controllable bidirectional clutch. The first forward pawl spring 505 is installed between the outer ring 501 and the first forward pawl 503 of the first controllable bidirectional clutch; the first reverse pawl spring 506 is installed between the outer ring 501 and the first reverse pawl 504 of the first controllable bidirectional clutch; multiple protruding first pawls 507a are evenly distributed along the circumferential direction on the first control disc 507, and the first pawls 507a extend into the space between the outer ring 501 and the first reverse pawl 504 of the first controllable bidirectional clutch; the first control disc 507 is axially limited by the fourth retaining ring 510 on the outer ring 501 of the first controllable bidirectional clutch; the first gear sector 508 is fixedly connected to the first control disc 507 by the first gear sector screw 509.

[0138] The left axle housing 109 is fixedly connected to the left side housing 101 of the first drive motor by screws 108, and the left axle housing 109 is fixedly connected to the left half-shaft sleeve 111 by screws 110; the left wheel hub 116 is supported on the left half-shaft sleeve 111 by bearings 113 and 114, and the left wheel hub 116 is fixedly connected to the left half-shaft 112 by screws 115; the left wheel rim 118 is fixedly connected to the left wheel hub 116 by bolts 117.

[0139] like Figure 1 As shown, the second drive motor 200, the third planetary gear train 800, the fourth planetary gear train 900, the second controllable bidirectional clutch 1000, the right half-shaft 212, the right axle housing 209, the right wheel rim 218, the right half-shaft sleeve 211, and the right wheel hub 216 are symmetrically distributed on both sides of the dual-motor independent drive synchronous shifting two-speed transmission system, respectively, along with the first drive motor 100, the first planetary gear train 300, the second planetary gear train 400, the first controllable bidirectional clutch 500, the left half-shaft 112, the left axle housing 109, the left wheel rim 118, the left half-shaft sleeve 111, and the left wheel hub 116.

[0140] The second drive motor 200 includes a right-side housing 201, a second stator 202, a left-side housing 203, a bearing 6 204, a bearing 7 205, a second motor shaft 206, and a second inner rotor 207.

[0141] The second stator 202 is fixedly installed in the end face annular groove between the left housing 203 and the right housing 201 of the second drive motor, and the three are fixedly connected as one unit. The left housing 203 and the right housing 201 of the second drive motor support the second motor shaft 206 through bearing 7 205 and bearing 6 204 respectively. The second inner rotor 207 is connected to the second motor shaft 206 through a spline. Bearing 6 204 is axially limited by the second inner rotor 207, the second inner rotor 207 is axially limited by bearing 7 205, and bearing 7 205 is axially limited by the left housing 203 of the second drive motor.

[0142] The third planetary gear train 800 is a single-row, single-stage planetary gear train, including the third planetary gear 801, the third sun gear 802, the third planetary carrier 803, the third planetary carrier cover 804, the No. 8 bearing 805, the No. 2 needle roller bearing 806, the third internal gear ring 807, the third internal gear ring screw 808, and the seventh retaining ring 809.

[0143] The third sun gear 802 is splinedly connected to the second motor shaft 206, and the third sun gear 802 is axially limited by the seventh snap ring 809 at the end of the second motor shaft 206. The third planetary carrier cover 804 has a radial cylindrical shaft that extends into the circular holes of the third planet gear 801 and the third planetary carrier 803 and can rotate freely. The third planetary carrier 803 and the third planetary carrier cover 804 are fixedly connected by multiple fastening screws. The third planetary carrier cover 804 is supported on the second motor shaft 206 by the No. 8 bearing 805, and the No. 8 bearing 805 is axially limited by the shoulder of the second motor shaft 206. The third planetary carrier 803 extends to the right to form a stepped hollow shaft, and the hollow shaft of the third planetary carrier 803 is supported on the right half shaft 212 by the No. 2 needle roller bearing 806. The third internal gear ring 807 is fixedly connected to the left side housing 203 of the second drive motor by the third internal gear ring screw 808.

[0144] In this embodiment, as a preferred embodiment, the planetary gear set characteristic parameters of the third planetary gear train 800 are the same as those of the first planetary gear train 300, and both are greater than 1.

[0145] The fourth planetary gear train 900 is a single-row, single-stage planetary gear train, including the fourth planetary gear 901, the fourth sun gear 902, the fourth planetary carrier 903, the fourth planetary carrier cover 904, the 9th bearing 905, the fourth internal gear ring 906, the eighth snap ring 907, the ninth snap ring 908, and the 10th bearing 909.

[0146] The fourth sun gear 902 is splinedly connected to the hollow shaft of the third planetary carrier 803, and the fourth sun gear 902 is axially limited by the eighth retaining ring 907 at the end of the hollow shaft of the third planetary carrier 803. The fourth planetary carrier cover 904 has a radial cylindrical shaft that extends into the circular holes of the fourth planet gear 901 and the fourth planetary carrier 903 and can rotate freely. The fourth planetary carrier 903 and the fourth planetary carrier cover 904 are fixedly connected by multiple fastening screws. The fourth planetary carrier cover 904 is supported on the third planetary carrier 803 by a bearing 905. On the 03, the 9th bearing 905 is axially limited by the shoulder of the hollow shaft of the third planetary carrier 803; the fourth planetary carrier 903 is connected to the stepped shaft spline of the right half shaft 212, and is axially limited by the ninth snap ring 908 on the stepped shaft of the right half shaft 212; the fourth internal gear ring 906 extends to the right to form a stepped hollow shaft, and the stepped hollow shaft of the fourth internal gear ring 906 is provided with a second spline 906a and a second engaging gear ring 906b, and the fourth internal gear ring 906 is supported on the right half shaft 212 by the 10th bearing 909;

[0147] In this embodiment, as a preferred embodiment, the planetary gear set characteristic parameters of the fourth planetary gear train 900 are the same as those of the second planetary gear train 400, and both are greater than 1.

[0148] like Figure 1 and Figure 3 As shown, the second controllable bidirectional clutch 1000 is located on the left side of the fourth planetary gear train 900. Its structure is exactly the same as that of the first controllable bidirectional clutch 500, including the second controllable bidirectional clutch outer ring 1001, the second controllable bidirectional clutch inner ring 1002, the second forward pawl 1003, the second reverse pawl 1004, the second forward pawl spring 1005, the second reverse pawl spring 1006, the second control plate 1007, the second gear sector 1008, the second gear sector screw 1009, the tenth retaining ring 1010, the eleventh retaining ring 1011, the second outer ring screw 1012, and the twelfth retaining ring 1013.

[0149] The inner ring 1002 of the second controllable bidirectional clutch is connected to the fourth internal gear ring 906 via a second spline 906a and is axially limited by a twelfth retaining ring 1013 on the second spline 906a. The outer ring 1001 of the second controllable bidirectional clutch has paired grooves and is fixedly connected to the second transmission housing 123 via a second outer ring screw 1012. The second forward pawl 1003 and the second reverse pawl 1004 are installed in pairs in the grooves of the outer ring 1001 of the second controllable bidirectional clutch and are freely rotatable. They are axially limited by an eleventh retaining ring 1011 on the outer ring 1001 of the second controllable bidirectional clutch. When the second forward pawl 1003 and the second reverse pawl 1004 fall, they can engage with the second controllable bidirectional clutch. The inner ring 1002 is recessed in the tooth root; the second forward pawl spring 1005 is installed between the outer ring 1001 and the second forward pawl 1003 of the second controllable bidirectional clutch; the second reverse pawl spring 1006 is installed between the outer ring 1001 and the second reverse pawl 1004 of the second controllable bidirectional clutch; multiple protruding second pawls 1007a are evenly distributed along the circumferential direction on the second control disc 1007, and the second pawls 1007a extend into the space between the outer ring 1001 and the second reverse pawl 1004 of the second controllable bidirectional clutch; the second control disc 1007 is axially limited by the tenth retaining ring 1010 on the outer ring 1001 of the second controllable bidirectional clutch; the second gear sector 1008 is fixedly connected to the second control disc 1007 by the second gear sector screw 1009.

[0150] The shift actuator 600 is located in the center of the upper part of the entire dual-motor independent drive synchronous shift two-speed transmission system. It is used to drive the bidirectional lead screw to rotate forward and backward, realize the left and right movement control of the first shift fork and the second shift fork, and thus realize the switching between high and low gears. The shift actuator 600 includes a shift motor 601, a shift motor screw 602, a shift motor cylindrical pin 603, a bearing 604 (No. 11), a shift motor shaft 605, a first shift gear 606, a bearing 607 (No. 12), a second shift gear 608, a two-way lead screw 609, a lead screw support screw 610 (No. 1), a left lead screw support arm 611, a bearing 612 (No. 13), a first shift fork 613, a second shift fork 614, a lead screw support screw 615, a right lead screw support arm 616, a bearing 617 (No. 14), a second engagement sleeve 618, a first engagement sleeve 619, a first splined hub 620, a centralized drive engagement gear ring 621, a second splined hub 622, a thirteenth retaining ring 623, and a fourteenth retaining ring 624.

[0151] The first splined hub 620 is splinedly connected to the left half-shaft 112, and the first splined hub 620 is axially limited by the thirteenth retaining ring 623 at the shaft end of the left half-shaft 112; the centralized drive engagement gear ring 621 is splinedly connected to the right half-shaft 212, and the centralized drive engagement gear ring 621 is axially limited by the fourteenth retaining ring 624 at the shaft end of the right half-shaft 212; the second splined hub 622 is splinedly connected to the right half-shaft 212, and the second splined hub 622 is axially limited by the protrusion formed on the end face of the centralized drive engagement gear ring 621; the first engagement sleeve 619 and the second engagement sleeve 618 are symmetrically arranged in the second... On both sides of the gear shifter 608, the surface of the first engaging sleeve 619 is provided with annular grooves, allowing it to slide freely on the first splined hub 620. The surface of the second engaging sleeve 618 is provided with annular grooves, allowing it to slide freely on the second splined hub 622. The housing of the shift motor 601 is fixedly connected to the second transmission housing 123 by shift motor screws 602 and shift motor cylindrical pins 603. The shift motor shaft 605 is provided with a stepped shaft, and its two ends are supported on the second transmission housing 123 and the first transmission housing 121 by bearings 11 and 12, respectively. Bearing 607 (No. 12) is axially limited by the shoulder of the shift motor shaft 605; the first shift gear 606 is fixedly connected to the shift motor shaft 605 by a flat key; the left support arm 611 of the lead screw is fixedly connected to the outer ring 501 of the first controllable bidirectional clutch by lead screw support screw 610 (No. 1); the right support arm 616 of the lead screw is fixedly connected to the outer ring 1001 of the second controllable bidirectional clutch by lead screw support screw 615 (No. 2); the bidirectional lead screw 609 is provided with a stepped shaft, and its two sides are symmetrically provided with threads of opposite directions; the two ends of the bidirectional lead screw 609 are respectively connected by bearings 612 (No. 13) and 614 (No. 6). 17 is supported on the left support arm 611 and the right support arm 616 of the lead screw. Bearings 612 (No. 13) and 617 (No. 14) are axially limited by the shoulder of the double-acting lead screw 609. The second shift gear 608 is located in the center of the double-acting lead screw 609 and is fixedly connected to the double-acting lead screw 609 by a flat key. The upper part of the first shift fork 613 is threaded and matched with the left side of the double-acting lead screw 609, and the lower fork body is inserted into the annular groove of the first engagement sleeve 619. The upper part of the second shift fork 614 is threaded and matched with the right side of the double-acting lead screw 609, and the lower fork body is inserted into the annular groove of the second engagement sleeve 618.

[0152] In this embodiment, preferably, the first engagement gear ring 406b and the concentrated drive engagement gear ring 621 are symmetrically arranged on both sides of the first spline hub 620; the distance between the second engagement gear ring 906b and the right end face of the second spline hub 622 is the same as the distance between the first engagement gear ring 406b and the left end face of the first spline hub 620; the length of the second spline hub 622 should satisfy the condition that when the first engagement sleeve 619 connects the first spline hub 620 and the concentrated drive engagement gear ring 621, the second engagement sleeve 618 is always only on the second spline hub 620. The splined hub 622 slides on the splined hub; the thread lengths on the left and right sides of the double-acting screw 609 should meet the following requirements: when the first engaging sleeve 619 and the second engaging sleeve 618 move to the left and right respectively, they can mesh with the first engaging gear ring 406b and the second engaging gear ring 906b respectively. When the first engaging sleeve 619 and the second engaging sleeve 618 move synchronously to the middle, the first engaging sleeve 619 can mesh with the concentrated drive engaging gear ring 621, but the first engaging sleeve 619 and the second engaging sleeve 618 will not collide with the second shift gear 608.

[0153] The reverse gear actuator 700 is located in the center of the lower part of the entire dual-motor independent drive synchronous shifting two-speed transmission system. Its output end is connected to the first controllable bidirectional clutch and the second controllable bidirectional clutch to control the locking direction of both. The reverse gear actuator 700 includes a reverse gear motor 701, a reverse gear motor screw 702, a reverse gear motor cylindrical pin 703, a No. 15 bearing 704, a second reverse gear 705, a reverse gear motor shaft 706, a first reverse gear 707, and a No. 16 bearing 708.

[0154] The reverse gear motor 701 housing is fixedly connected to the second transmission housing 123 via reverse gear motor screws 702 and reverse gear motor cylindrical pins 703. The reverse gear motor shaft 706 is provided with a stepped shaft, and its two ends are supported on the second transmission housing 123 and the first transmission housing 121 respectively by bearings 704 and 708. The bearings 704 and 708 are axially limited by the shoulders of the reverse gear motor shaft 706. The first reverse gear 707 and the second reverse gear 705 are symmetrically arranged on both sides of the reverse gear motor shaft 706. The first reverse gear 707 meshes with the first gear sector 508 and is fixedly connected to the reverse gear motor shaft 706 via a flat key. The second reverse gear 705 meshes with the second gear sector 1008 and is fixedly connected to the reverse gear motor shaft 706 via a flat key.

[0155] The right axle housing 209 is fixedly connected to the right side housing 201 of the second drive motor by screws 208, and the right axle housing 209 is fixedly connected to the right half-shaft sleeve 211 by screws 210; the right wheel hub 216 is supported on the right half-shaft sleeve 211 by bearings 213 and 214, and the right wheel hub 216 is fixedly connected to the right half-shaft 212 by screws 215; the right wheel rim 218 is fixedly connected to the right wheel hub 216 by bolts 217.

[0156] The first transmission housing 121 is fixedly connected to the right side housing 103 of the first drive motor by screws 120, and the first transmission housing 121 is fixedly connected to the second transmission housing 123 by screws 122; the second transmission housing 123 is fixedly connected to the left side housing 203 of the second drive motor by screws 124.

[0157] like Figure 2 The diagram illustrates the main connection relationships of the dual-motor independent drive synchronous shifting two-speed transmission system. The dual-motor independent drive synchronous shifting two-speed transmission system provided by this invention has four operating modes: forward first gear; forward second gear; reverse gear; and centralized drive.

[0158] The working principles of the four modes and the mode switching process are explained below: Regarding the rotation speed relationship, the rotation direction of the wheels is set to positive when the electric vehicle is moving forward and negative when it is reversing; Since the outer ring of the controllable bidirectional clutch is fixed in this invention, when the electric vehicle is moving forward, if the inner ring of the controllable bidirectional clutch is set to turn negative, the forward pawl will fall down and the controllable bidirectional clutch will engage; otherwise, it will disengage.

[0159] 1. Vehicle starts from a standstill and accelerates into first gear: When the vehicle starts from a standstill and accelerates into first gear, the first engagement sleeve 619 and the second engagement sleeve 618 engage only with the first splined hub 620 and the second splined hub 622. The reverse gear pawls 504 and 1004 of the controllable bidirectional clutches 500 and 1000 are lifted by the reverse gear pawl springs 506 and 1006. The first motor shaft 106 and the first inner rotor 107 rotate synchronously forward. Let the speed of the first motor shaft 106 at this time be n. M Then the first sun gear 302 rotates clockwise, and the rotational speed is n. M Since the first internal gear ring 307 is fixed, according to the formula for the rotational speed of a single-row, single-stage planetary gear train, the rotational speed of the first planetary carrier 303 can be obtained as follows: With the direction of rotation positive (k1 is a characteristic parameter of the planetary gear set 300, i.e., the ratio of the number of teeth on the ring gear to the number of teeth on the sun gear, and k1>1), then the rotational speed of the second sun gear 402 is: With the steering in positive direction, and since the second planetary carrier 403 is connected to a large inertia system such as wheels, its instantaneous speed can be considered constant, i.e., the instantaneous speed of the second planetary carrier 403 is 0. Therefore, according to the speed formula for a single-row, single-stage planetary gear train, the speed of the second internal gear ring 406 can be obtained as follows: With the steering direction negative (k2 is a characteristic parameter of the planetary gear set 400, i.e., the ratio of the number of teeth on the ring gear to the number of teeth on the sun gear, and k2>1), the rotational speed of the inner ring 502 of the first controllable bidirectional clutch is: When the steering is negative, the first forward pawl 503 drops, the controllable two-way clutch 500 engages, and the controllable two-way clutch is in first gear as follows: Figure 4 As shown. The second motor shaft 206 and the second inner rotor 207 rotate synchronously in the forward direction, and the speed is n. M Similarly, the steering of the inner ring 1002 of the second controllable bidirectional clutch is negative, the second forward pawl 1003 falls, and the second controllable bidirectional clutch 1000 engages.

[0160] 2. First gear forward state: When the vehicle is in first gear forward, the first engagement sleeve 619 and the second engagement sleeve 618 engage only with the first splined hub 620 and the second splined hub 622. The reverse pawls 504 and 1004 of the controllable two-way clutches 500 and 1000 are raised under the action of the reverse pawl springs 506 and 1006, and the forward pawls 503 and 1003 fall down, engaging the controllable two-way clutches 500 and 1000. Figure 4 As shown. Motor shafts 106 and 206 rotate synchronously with inner rotors 107 and 207. Let the rotational speed of motor shafts 106 and 206 at this time be n. M Then the first sun gear 302 rotates clockwise, and the rotational speed is n. M Since the first internal gear ring 307 is fixed, according to the formula for the rotational speed of a single-row, single-stage planetary gear train, the rotational speed of the first planetary carrier 303 can be obtained as follows: If the direction of rotation is positive, then the rotational speed of the second sun gear 402 is: With the steering in positive direction, and since the second internal gear ring 406 is locked by the controllable two-way clutch 500, the rotational speed of the second planetary carrier 403 can be obtained according to the formula for the rotational speed of a single-row, single-stage planetary gear train. Since the direction of rotation is positive, similarly, the rotational speed of the fourth planetary carrier 903 is... With the steering direction positive (k3 is the characteristic parameter of the planetary gear set of the third planetary gear train 800, i.e., the ratio of the number of teeth on the ring gear of the third planetary gear set to the number of teeth on the sun gear; k4 is the characteristic parameter of the planetary gear set of the fourth planetary gear train 900, i.e., the ratio of the number of teeth on the ring gear of the fourth planetary gear set to the number of teeth on the sun gear, and k3 = k1 > 1, k4 = k2 > 1), then the rotational speeds of the left half-shaft 112, right half-shaft 212, left hub 116, right hub 216, left wheel rim 118, and right wheel rim 218 are all... like Figure 6As shown, when the vehicle is in first gear, power is transmitted sequentially through the first motor shaft 106 (second motor shaft 206), the first sun gear 302 (third sun gear 802), the first planetary gear 301 (third planetary gear 801), the first planetary carrier 303 (third planetary carrier 803), the second sun gear 402 (fourth sun gear 902), the second planetary gear 401 (fourth planetary gear 901), the second planetary carrier 403 (fourth planetary carrier 903), the left half-shaft 112 (right half-shaft 212), and the left wheel hub 116 (right wheel hub 216) to the left wheel rim 118 (right wheel rim 218). At this time, the car is driven independently by the first drive motor and the second drive motor, each in first gear ratio (1+k1)(1+k2), driving the left and right wheels forward.

[0161] 3. Shifting from first gear to second gear: The power output by the shift motor 601 is transmitted to the second shift gear 608 via the shift motor shaft 605 and the first shift gear 606, thereby driving the bidirectional lead screw 609 to rotate. The first shift fork 613 and the second shift fork 614 push the first engagement sleeve 619 and the second engagement sleeve 618 to move synchronously to the left and right. The first engagement sleeve 619 engages with the first engagement ring gear 406b, and the second engagement sleeve 618 engages with the second engagement ring gear 906b. Since the second planetary carrier 403 rotates forward in the first gear state, and the second internal ring gear 406 is locked by the first controllable bidirectional clutch 500, the second planetary carrier 403 will drive the second internal ring gear 406 to rotate forward at this time. As a result, the inner ring 502 of the first controllable bidirectional clutch will have a tendency to rotate forward. The first forward pawl 503 is lifted, and the first controllable bidirectional clutch 500 is automatically disengaged. Similarly, the second controllable bidirectional clutch 1000 is automatically disengaged at this time.

[0162] 4. Second forward gear: When the vehicle is in second forward gear, the first engagement sleeve 619 engages the first splined hub 620 with the first engagement gear ring 406b, and the second engagement sleeve 618 engages the second splined hub 622 with the second engagement gear ring 906b. The reverse pawls 504 and 1004 of the controllable two-way clutches 500 and 1000 are lifted by the reverse pawl springs 506 and 1006, and the forward pawls 503 and 1003 are automatically lifted. Both controllable two-way clutches 500 and 1000 are disengaged. Figure 3 As shown. Motor shafts 106 and 206 rotate synchronously with inner rotors 107 and 207. Let the rotational speed of motor shafts 106 and 206 at this time be n. M Then the first sun gear 302 rotates clockwise, and the rotational speed is n. M Since the first internal gear ring 307 is fixed, according to the formula for the rotational speed of a single-row, single-stage planetary gear train, the rotational speed of the first planetary carrier 303 can be obtained as follows: If the direction of rotation is positive, then the rotational speed of the second sun gear 402 is: With the steering in positive direction, since the second internal gear ring 406 is fixedly connected to the left half-shaft 112 via the first engaging sleeve 619, and the second planetary carrier 403 is splinedly connected to the left half-shaft 112, the second internal gear ring 406 and the second planetary carrier 403 rotate at the same speed. According to the speed formula for a single-row, single-stage planetary gear train, the speed of the second sun gear 402 is the same as the speed of the second internal gear ring 406 and the second planetary carrier 403. The direction of rotation is positive. Similarly, the rotational speed of the fourth planetary carrier 903 is... With the steering direction positive (k3 is the characteristic parameter of the planetary gear set 800 of the third planetary gear train, and k3 = k1 > 1), the rotational speeds of the left half-shaft 112, right half-shaft 212, left hub 116, right hub 216, left wheel rim 118, and right wheel rim 218 are all... The direction is positive. For example... Figure 7 As shown, when the vehicle is in second gear, power is transmitted sequentially through the first motor shaft 106 (second motor shaft 206), the first sun gear 302 (third sun gear 802), the first planetary gear 301 (third planetary gear 801), the first planetary carrier 303 (third planetary carrier 803), the second sun gear 402 (fourth sun gear 902), the second planetary gear 401 (fourth planetary gear 901), the second internal gear ring 406 (fourth internal gear ring 906), the second planetary carrier 403 (fourth planetary carrier 903), the left half-shaft 112 (right half-shaft 212), and the left wheel hub 116 (right wheel hub 216) to the left wheel rim 118 (right wheel rim 218). At this time, the car is driven by the first drive motor and the second drive motor, each in second gear (1+k1), independently driving the left and right wheels forward.

[0163] 5. The vehicle shifts from second gear to first gear: The power output from the shift motor 601 is transmitted to the second shift gear 608 via the shift motor shaft 605 and the first shift gear 606, thereby driving the bidirectional lead screw 609 to rotate. The first shift fork 613 and the second shift fork 614 push the first engagement sleeve 619 and the second engagement sleeve 618 to move synchronously towards the center, causing the first engagement sleeve 619 to separate from the first engagement gear ring 406b, and the second engagement sleeve 618 to separate from the second engagement gear ring 906b. That is, the second internal gear ring 406 disengages from the left half shaft 112. As the load on the second planetary gear train 400 decreases, the speed of the second sun gear 402 will correspondingly increase. As the second planetary carrier 403 is connected to a large inertia system such as wheels, its instantaneous speed can be considered constant. According to the speed formula of a single-row, single-stage planetary gear system, the speed of the second internal gear ring 406 decreases. When the speed of the second sun gear 402 increases to (1+k2) times the speed of the second planetary carrier 403, the speed of the second internal gear ring 406 decreases to 0 or even tends to become negative. That is, the inner ring 502 of the first controllable bidirectional clutch tends to rotate in the opposite direction. The first forward pawl 503 falls, and the first controllable bidirectional clutch 500 automatically engages. Similarly, at this time, the second controllable bidirectional clutch 1000 automatically engages, and the vehicle shifts from second gear to first gear.

[0164] 6. Switching from a stationary state to reverse gear: This mode switching process is the same as the process of accelerating from a standstill and engaging first gear, except that the rotation directions of motor shafts 106 and 206 are reversed. Based on the analysis of the process of accelerating from a standstill and engaging first gear, the rotational speeds of the inner rings 502 and 1002 of the controllable two-way clutch are: When the steering is forward, the forward pawls 503 and 1003 will automatically lift, requiring the reverse motor 701 to start. Its output power is transmitted via the reverse motor shaft 706, reverse gears 705 and 707 to the gear sector 508 and 1008, thereby driving the control discs 507 and 1007 to rotate. The pawls 507a and 1007a on the control discs 507 and 1007 push the reverse pawls 504 and 1004 of the controllable bidirectional clutches 500 and 1000 to drop, thus allowing the controllable bidirectional clutches 500 and 1000 to engage even when the motor shafts 106 and 206 rotate in the opposite direction. Figure 5 As shown.

[0165] 7. Reverse Gear: When the vehicle is in reverse gear, the first engagement sleeve 619 and the second engagement sleeve 618 engage only with the first splined hub 620 and the second splined hub 622. The motor shafts 106 and 206 rotate in opposite directions. The forward pawls 503 and 1003 of the controllable bidirectional clutches 500 and 1000 automatically lift, and the reverse pawls 504 and 1004 fall, engaging the controllable bidirectional clutches 500 and 1000. The power transmission route in reverse gear is the same as in first gear. The reverse gear ratio of the dual-motor independently driven synchronous shifting two-speed transmission system is (1+k1)(1+k2). At this time, the car is driven by the first drive motor and the second drive motor, each in first gear ratio (1+k1)(1+k2), independently driving the left and right wheels to reverse.

[0166] 8. Centralized Drive State: When one motor fails, the power output by the shift motor 601 is transmitted to the second shift gear 608 via the shift motor shaft 605 and the first shift gear 606, thereby driving the bidirectional lead screw 609 to rotate. The first shift fork 613 and the second shift fork 614 push the first engagement sleeve 619 and the second engagement sleeve 618 to move synchronously towards the center. If the previous state was the second gear state, the first engagement sleeve 619 and the first engagement gear ring 406b, and the second engagement sleeve 618 and the second engagement gear ring 906b will first separate simultaneously, thereby switching to the first gear state. Then the first engagement sleeve 619 and the second engagement sleeve 618 continue to move synchronously towards the center until the first engagement sleeve 619 engages the first spline hub 620 with the centralized drive engagement gear ring 621, and the mode switching process is completed. During this process, the second engagement sleeve 618 always slides on the second spline hub 622. If the first drive motor 100 malfunctions, because the second engagement sleeve 618 always slides on the second splined hub 622, the fourth planetary carrier 903 remains in first gear, so the rotational speed of the fourth planetary carrier 903 is... With the steering in positive direction, since the left half-shaft 112 is fixedly connected to the first splined hub 620 and the second planetary carrier 403, and the right half-shaft 212 is fixedly connected to the concentrated drive engagement gear ring 621, the fourth planetary carrier 903, and the second splined hub 622, and the first splined hub 620 is fixedly connected to the concentrated drive engagement gear ring 621, the second planetary carrier 403 and the fourth planetary carrier 903 rotate synchronously at a speed of [missing value]. With the direction of rotation positive, and considering the drag loss and other resistance within the first drive motor 100, the instantaneous speed of the second sun gear 402 can be assumed to be 0. Therefore, according to the speed formula for a single-row, single-stage planetary gear train, the speed of the second internal gear ring 406 can be obtained as follows: When the steering is positive, the inner ring 502 of the first controllable two-way clutch tends to rotate in the positive direction, the first forward pawl 503 lifts, and the first controllable two-way clutch 500 automatically disengages. At this time, the second planetary gear train 400 has no fixed components and can rotate freely, without transmitting power. Figure 8As shown, when the first drive motor 100 fails, power is sequentially transmitted through the second motor shaft 206, the third sun gear 802, the third planetary gear 801, the third planetary carrier 803, the fourth sun gear 902, the fourth planetary gear 901, the fourth planetary carrier 903, the right half-shaft 212, the left half-shaft 112, the right wheel hub 216, and the left wheel hub 116 to the right wheel rim 218 and the left wheel rim 118. At this time, the car is driven forward by the second drive motor simultaneously driving both wheels in first gear ratio (1+k1)(1+k2). When reversing is required, the reverse gear actuator is controlled to change the locking direction of the second controllable bidirectional clutch, which can also realize the reverse driving of the car driven by the second drive motor.

[0167] Similarly, when the second drive motor 200 malfunctions, the fourth planetary carrier 903 rotates synchronously with the second planetary carrier 403, and its rotational speed is... With the steering in positive direction, and considering the drag loss and other resistance within the second drive motor 200, the instantaneous speed of the fourth sun gear 902 can be assumed to be 0. Based on the speed formula for a single-row, single-stage planetary gear train, the speed of the fourth internal gear ring 906 can be obtained as follows: When the steering is positive, the inner ring 1002 of the second controllable two-way clutch tends to rotate in the positive direction, the second forward pawl 1003 lifts, and the second controllable two-way clutch 1000 automatically disengages. At this time, the fourth planetary gear train 900 has no fixed components and can rotate freely without transmitting power. Figure 9 As shown, when the second drive motor 200 fails, power is sequentially transmitted through the first motor shaft 106, the first sun gear 302, the first planetary gear 301, the first planetary carrier 303, the second sun gear 402, the second planetary gear 401, the second planetary carrier 403, the left half-shaft 112, the right half-shaft 212, the left wheel hub 116, and the right wheel hub 216 to the left wheel rim 118 and the right wheel rim 218. At this time, the car is driven forward by the first drive motor simultaneously driving both wheels in first gear ratio (1+k1)(1+k2). When reversing is required, the reverse gear actuator is controlled to change the locking direction of the first controllable bidirectional clutch, which can also realize the car reversing under the drive of the first drive motor.

[0168] It should be noted that the forward first gear, forward second gear, and reverse gear states are the normal non-fault states of the vehicle described in this invention. When a fault occurs, such as a fault in one drive motor or a fault in the controllable bidirectional clutch, the vehicle will be controlled to enter a centralized drive state to ensure that the vehicle can continue to drive in a fault-tolerant manner. At this time, the drive power is half of the non-fault drive power.

[0169] Although the embodiments of the present invention have been disclosed above, they are not limited to the applications listed in the specification and embodiments. They can be applied to various fields suitable for the present invention. For example, the illustrations of the present invention depict a dual-motor independent drive synchronous shifting two-speed transmission system designed for a commercial vehicle with an integral drive axle, and an electric vehicle. For passenger vehicles using a disconnected drive axle, the same application scheme and the same application value are applicable. For those skilled in the art, other modifications can be easily implemented. Therefore, without departing from the general concept defined by the claims and their equivalents, the present invention is not limited to the specific details and the illustrations shown and described herein.

Claims

1. A dual-motor independently driven synchronous shifting two-speed transmission system, characterized in that, include: Transmission housing; The first drive motor is fixed to one end of the gearbox housing; The second drive motor is fixed to the other end of the transmission housing; The left half-shaft is rotatably supported at the center of the first drive motor and extends outward; The right half-shaft is rotatably supported at the center of the second drive motor and extends outward; The first planetary gear set has its input terminal connected to the first drive motor; The second planetary gear set has its input connected to the first planetary gear set. A first controllable bidirectional clutch is disposed between the transmission housing and the ring gear of the second planetary gear set, which can be controlled to enable the ring gear of the second planetary gear set to be locked bidirectionally and as needed by the transmission housing. The third planetary gear set has its input end connected to the second drive motor; The fourth planetary gear set has its input connected to the third planetary gear set; A second controllable bidirectional clutch is arranged between the transmission housing and the ring gear of the fourth planetary gear set, which can be controlled to enable the ring gear of the fourth planetary gear set to be locked bidirectionally and as needed by the transmission housing. The reverse gear actuator is located in the lower middle part of the transmission housing, and its output end is connected to the first controllable bidirectional clutch and the second controllable bidirectional clutch to control the locking direction of the two clutches. The first splined hub is connected to the splined inner end of the left half-shaft; The first engaging sleeve slides on the first splined hub, and the first engaging sleeve is provided with an annular groove; A bidirectional lead screw has symmetrical reverse threads on its left and right sides, and the bidirectional lead screw is rotatably supported on the first controllable bidirectional clutch and the second controllable bidirectional clutch. The first shift fork has its upper part threaded into one end of the bidirectional lead screw, and its lower part inserted into the annular groove of the first engagement sleeve. The second splined hub is connected to the splined right half-shaft. The second engaging sleeve slides on the second splined hub, and the second engaging sleeve is provided with an annular groove; The second shift fork has its upper part threadedly engaged with the other end of the bidirectional lead screw, and its lower part inserted into the annular groove of the second engagement sleeve. The second shift fork and the first shift fork are symmetrically arranged on both sides of the bidirectional lead screw. A centralized drive engagement gear ring is connected to the splined inner end of the right half-shaft; The shift actuator is located in the upper middle part of the transmission housing and is used to drive the bidirectional lead screw to rotate in both directions, thereby controlling the left and right movement of the first shift fork and the second shift fork. The left axle housing is fixedly connected to the housing of the first drive motor; The right axle housing is fixedly connected to the housing of the second drive motor; The left half-shaft sleeve is fixedly connected to the left axle housing; The right half-shaft sleeve is fixedly connected to the right axle housing; The left wheel hub is fixedly connected to the outer end flange of the left half-shaft; The right wheel hub is fixedly connected to the outer end flange of the right half-shaft; The left wheel rim is fixedly connected to the left wheel hub; The right wheel rim is fixedly connected to the right wheel hub.

2. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 1, characterized in that, The first drive motor includes, The first drive motor housing includes a first drive motor main housing and a first drive motor housing cover, wherein the first drive motor main housing and the first drive motor housing cover are fixedly connected to form a closed cavity; The first inner rotor is housed within the first drive motor housing and is rotatably supported at the center of the first drive motor main housing and the first drive motor housing cover on both sides. The first stator is housed within the first drive motor housing and is fixedly connected to the main housing of the first drive motor. The first motor shaft is a hollow shaft used to support the left half shaft and is fixedly connected to the center of the first inner rotor; The second drive motor includes, The second drive motor housing includes a second drive motor main housing and a second drive motor housing cover, and the second drive motor main housing and the second drive motor housing cover are fixedly connected to form a closed cavity; The second inner rotor is housed within the second drive motor housing and is rotatably supported at the center of the second drive motor main housing and the second drive motor housing cover on both sides. The second stator is housed within the housing of the second drive motor and is fixedly connected to the main housing of the second drive motor. The second motor shaft is a hollow shaft used to support the right half shaft and is fixedly connected to the center of the second inner rotor.

3. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 2, characterized in that, The first planetary array includes, The first sun gear is fixedly connected to the output end of the first motor shaft; Multiple first planetary gears, which mesh and match with the first sun gear; The first internal gear ring meshes with the first planetary gear, and the first internal gear ring is fixedly connected to the first drive motor housing. The first planetary carrier has a hollow shaft and is rotatably supported on the left half-shaft; A first planetary carrier cover, which is rotatably supported on the first motor shaft and fixedly connected to the first planetary carrier, is used to rotatably support the plurality of first planetary gears; The second planetary array includes, The second sun gear is fixedly connected to the first planet carrier; Multiple second planetary gears that mesh with the second sun gear; The second internal gear ring meshes with the second planetary gear, and the second internal gear ring is provided with a first stepped hollow shaft and is rotatably supported on the left half shaft. The first stepped hollow shaft is provided with a first spline and a first engaging gear ring. The second planetary carrier is splinedly connected to the left half-shaft; The second planetary carrier cover is rotatably supported on the first planetary carrier, and the second planetary carrier cover is fixedly connected to the second planetary carrier for rotatably supporting the plurality of second planetary gears; The third planetary arrangement includes, The third sun gear is fixedly connected to the output end of the second motor shaft; Multiple third planetary gears, which mesh and match with the third sun gear; The third internal gear ring meshes with the third planetary gear, and the third internal gear ring is fixedly connected to the second drive motor housing; The third planetary carrier has a hollow shaft and is rotatably supported on the right half-shaft; The third planetary carrier cover is rotatably supported on the second motor shaft, and the third planetary carrier cover is fixedly connected to the third planetary carrier for rotatably supporting the plurality of third planetary gears; The fourth planetary arrangement includes, The fourth sun gear is fixedly connected to the third planet carrier; Multiple fourth planetary gears, which mesh and match with the fourth sun gear; The fourth internal gear ring meshes with the fourth planetary gear, and the fourth internal gear ring is provided with a second stepped hollow shaft and is rotatably supported on the right half shaft. The second stepped hollow shaft is provided with a second spline and a second engaging gear ring. The fourth planetary carrier is splinedly connected to the right half-shaft; A fourth planetary carrier cover, which is rotatably supported on the third planetary carrier and is fixedly connected to the fourth planetary carrier, is used to rotatably support the plurality of fourth planetary gears; The first planetary array and the third planetary array have identical structural parameters, and the second planetary array and the fourth planetary array have identical structural parameters.

4. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 3, characterized in that, The first controllable bidirectional clutch includes, The outer ring of the first controllable bidirectional clutch is fixedly connected to the transmission housing; The inner ring of the first controllable bidirectional clutch is fixedly connected to the second inner gear ring via the first spline. Multiple first forward pawls; A plurality of first reverse pawls are mounted in pairs with the plurality of first forward pawls between the outer ring of the first controllable bidirectional clutch and the inner ring of the first controllable bidirectional clutch; A plurality of first forward pawl springs are mounted between the plurality of first forward pawls and the outer ring of the first controllable bidirectional clutch; A plurality of first reverse gear pawl springs are mounted between the plurality of first reverse gear pawls and the outer ring of the first controllable bidirectional clutch; A first control disc has a plurality of protruding first pawls evenly distributed on its side surface. The plurality of first pawls are inserted between the outer ring of the first controllable bidirectional clutch and the plurality of first reverse gear pawls. A toothed sector is provided on the outer circumference of the first control disc. The second controllable bidirectional clutch, include, The outer ring of the second controllable bidirectional clutch is fixedly connected to the transmission housing; The inner ring of the second controllable bidirectional clutch is fixedly connected to the fourth internal gear ring via the second spline. Multiple second forward pawls; Multiple second reverse pawls are mounted in pairs with the multiple second forward pawls between the outer ring of the second controllable bidirectional clutch and the inner ring of the second controllable bidirectional clutch; A plurality of second forward pawl springs are mounted between the plurality of second forward pawls and the outer ring of the second controllable bidirectional clutch; A plurality of second reverse gear pawl springs are mounted between the plurality of second reverse gear pawls and the outer ring of the second controllable bidirectional clutch; The second control disc has multiple protruding second pawls evenly distributed on its side surface. The multiple second pawls are inserted between the outer ring of the second controllable bidirectional clutch and the multiple second reverse gear pawls. The outer circumference of the second control disc is provided with a toothed sector.

5. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 4, characterized in that, The reverse gear actuator includes, Reverse gear motor housing, which is fixedly connected to the transmission housing; The reverse gear motor shaft is rotatably supported on the transmission housing; The first reverse gear meshes with the first control disk gear sector to drive the first control disk to rotate, and the first reverse gear is splinedly connected to the reverse motor shaft; The second reverse gear meshes with the gear sector of the second control disk to drive the second control disk to rotate. The second reverse gear is splinedly connected to the reverse motor shaft, and the second reverse gear and the first reverse gear are symmetrically arranged on both sides of the reverse motor shaft.

6. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 3, characterized in that, The gear shifting actuator includes, A shift motor housing, which is fixedly connected to the transmission housing; The shift motor shaft is rotatably supported on the transmission housing; The first shift gear is centrally located on the shift motor shaft and connected to it by a spline; The second shift gear meshes with the first shift gear and is fixedly connected to the center of symmetry of the bidirectional lead screw.

7. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 6, characterized in that, The first engagement gear ring and the centralized drive engagement gear ring are symmetrically arranged on both sides of the first spline hub; the distance between the second engagement gear ring and the right end face of the second spline hub is the same as the distance between the first engagement gear ring and the left end face of the first spline hub; the length of the second spline hub should satisfy that when the first engagement sleeve connects the first spline hub and the centralized drive engagement gear ring, the second engagement sleeve always slides only on the second spline hub. The thread lengths on the left and right sides of the bidirectional lead screw should satisfy the following conditions: when the first engagement sleeve and the second engagement sleeve move to the left and right respectively, the first engagement sleeve and the second engagement sleeve can respectively mesh with the first engagement gear ring and the second engagement gear ring; and when the first engagement sleeve and the second engagement sleeve move synchronously to the center, the first engagement sleeve can mesh with the centralized drive engagement gear ring, but the first engagement sleeve and the second engagement sleeve will not collide with the second shift gear.

8. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 1, characterized in that, By controlling the reverse gear actuator to change the locking direction of the first and second controllable bidirectional clutches, and by controlling the shift actuator to change the rotation direction of the bidirectional lead screw, the dual-motor independently driven synchronous shifting two-speed transmission system can switch between four operating modes, including... The forward gear mode is used when the first drive motor and the second drive motor each have a first gear ratio. The left and right wheels are driven independently to move forward. The forward second gear mode is used when the first drive motor and the second drive motor are each in the second gear transmission ratio. The left and right wheels are driven independently to move forward. In reverse gear mode, the first drive motor and the second drive motor are each in first gear ratio. Down, the left and right wheels are independently driven to reverse. The centralized drive mode is used to allow the non-faulty second drive motor or the first drive motor to operate in a first gear ratio when either the first drive motor or the second drive motor fails. In the next episode, both wheels are driven forward or backward simultaneously. in, These are the characteristic parameters of the first and third planetary arrays, and ; These are the characteristic parameters of the second and fourth planetary arrays, and .

9. The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 2, characterized in that, The transmission housing includes a first transmission housing and a second transmission housing, which are fixedly connected. The first transmission housing and the first drive motor housing are fixedly connected and are used to house the first planetary gear set, the second planetary gear set, and the first controllable bidirectional clutch. The second transmission housing and the second drive motor housing are fixedly connected and are used to house the first splined hub, the first engagement sleeve, the bidirectional lead screw, the first shift fork, the second splined hub, the second engagement sleeve, the second shift fork, the centralized drive engagement gear ring, the third planetary gear set, the fourth planetary gear set, and the second controllable bidirectional clutch.

10. An electric vehicle, characterized in that, The dual-motor independent drive synchronous shifting two-speed transmission system as described in claim 1 is used.

Images