Dual motor coupled transmission for tracked vehicles

Abstract

The present invention relates to a dual-motor coupling transmission device for a tracked vehicle, comprising two electric drive mechanisms and a fixed-axis gear reduction coupling mechanism arranged symmetrically, each electric drive mechanism correspondingly driving one track mechanism; the electric drive mechanism comprises a motor, a speed change mechanism, and a single planetary gear coupling mechanism which are sequentially connected in transmission; a double planetary gear differential coupling mechanism is arranged between the two motors, one end of the output shaft of the speed change mechanism is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; the output shafts of the two speed change mechanisms are coupled through the double planetary gear differential coupling mechanism; the two ends of the fixed-axis gear reduction coupling mechanism are respectively coupled and connected to the two single planetary gear coupling mechanisms, and at the same time, the middle part of the fixed-axis gear reduction coupling mechanism is coupled and connected to the double planetary gear differential coupling mechanism. The present invention uses a multi-planetary gear transmission mechanism as a power coupling mechanism, changes the power flow direction in the transmission system by adding a mode switching mechanism, and at the same time regulates the motor, so as to realize the precise control of the output power of the track wheels on both sides, and achieve the effect of small radius steering and center steering during high-efficiency travel.

Description

Technical Field

[0001] The invention belongs to the technical field of track electric drive, and relates to a dual-motor coupling transmission device for a track vehicle. Background Art

[0002] The steering of traditional tracked vehicles is achieved through the speed difference of the tracks on both sides. The transmission system generates the speed difference of the tracks on both sides through the relevant clutch / brake, or hydraulic, electrical and other speed control elements. Unlike wheeled vehicles, the steering of tracked vehicles is power steering, which requires the power of the power system to overcome the steering resistance of the road. Difficult roads or small radius steering conditions require a large steering drive torque. In order to achieve the steering of tracked vehicles, the inner track needs to provide braking force and the outer track needs to provide driving force. When the vehicle speed is high, the inner track will generate a large steering return power (braking power); if this part of the braking power can be efficiently transferred to the outer track, it can greatly save the input power of the power source.

[0003] Electrification is the development trend of vehicle power transmission system. Tracked vehicles use motors for driving and steering, which can greatly improve maneuverability. The planetary gear mechanism is used as the coupling mechanism of the transmission system, and the design can realize a dual-output hybrid tracked vehicle transmission system, which can eliminate the complex steering device and realize independent and precise control of the tracks on both sides. By controlling the torque of the tracks on both sides, high-efficiency steering and center steering can be achieved.

[0004] The dual-motor drive system can realize flexible power distribution, which has become the development trend of electric drive systems. It can also easily realize the coupling and decoupling of drive and steering, and is the development direction of pure electric drive systems for tracked vehicles. Summary of the invention

[0005] In view of this, the present invention proposes a dual-motor coupling transmission device for a tracked vehicle, which includes two drive motors and a multi-planetary gear transmission mechanism as a power coupling mechanism. By adding a mode switching mechanism to change the power flow in the transmission system and regulating the motor at the same time, precise control of the output power of the track wheels on both sides can be achieved, thereby achieving the effect of small radius steering and center steering during high-efficiency travel.

[0006] In order to achieve the above object, the present invention provides the following technical solutions:

[0007] A dual-motor coupling transmission device for a tracked vehicle comprises two electric drive mechanisms and a fixed-axis gear reduction coupling mechanism arranged symmetrically, each electric drive mechanism correspondingly drives one track mechanism; the electric drive mechanism comprises a motor, a speed change mechanism, and a single planetary gear coupling mechanism which are sequentially connected in transmission; a double planetary gear differential coupling mechanism is arranged between the two motors, one end of the output shaft of the speed change mechanism is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; the output shafts of the two speed change mechanisms are coupled through the double planetary gear differential coupling mechanism;

[0008] The two ends of the fixed-axis gear reduction coupling mechanism are respectively coupled to the two single planetary gear coupling mechanisms, and at the same time, the middle part of the fixed-axis gear reduction coupling mechanism is coupled to the double planetary gear differential coupling mechanism.

[0009] Further, the speed change mechanism is a two-speed planetary reduction mechanism, including a two-speed reduction inner planet carrier, a two-speed reduction outer planet carrier, a first-stage reduction sun gear, a second-stage reduction sun gear, an inner planet gear, an outer planet gear, a two-speed reduction ring gear and two brakes;

[0010] The outer planetary gear is arranged on the two-speed reduction outer planetary carrier, the inner planetary gear is arranged on the two-speed reduction inner planetary carrier, the two-speed reduction outer planetary carrier is fixedly connected to the two-speed reduction inner planetary carrier; the motor output shaft is connected to the first-stage reduction sun gear, and the inner planetary gear is meshed with the first-stage reduction sun gear; the inner side of the outer planetary gear is meshed with the inner planetary gear and the second-stage reduction sun gear at the same time, and the outer side is meshed with the two-speed reduction gear ring for transmission; the two-speed reduction gear ring is fixedly provided with a two-speed reduction output shaft, one end of the two-speed reduction output shaft is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism;

[0011] The two brakes are respectively arranged on the two-speed reduction outer planetary carrier and the reduction secondary sun gear, and the two-speed shifting is realized by braking switching through the two brakes.

[0012] Further, the single planet row coupling mechanism includes a planet row sun gear, a single planet row planet carrier, a single planet row planet gear, and a single planet row ring gear;

[0013] The single planetary gear ring is fixedly connected to the two-speed reduction output shaft; the single planetary gear is arranged on the single planetary gear carrier and meshes with the single planetary gear ring; one end of the single planetary gear sun gear is meshed with the single planetary gear, and the other end is meshed with the fixed axis gear reduction coupling mechanism; the single planetary gear carrier is fixedly connected with a power output shaft, and the crawler mechanism is driven by the power output shaft.

[0014] Further, the double planetary gear differential coupling mechanism comprises a left sun gear, a left planetary gear, a right sun gear, a right planetary gear, a double planetary gear carrier, and a double planetary gear ring;

[0015] The left sun gear and the right sun gear are arranged on the left and right sides, and are fixedly connected to the two-speed reduction output shafts on the corresponding sides respectively; the left planetary gear and the right planetary gear are rotatably arranged in the double planetary gear carrier, and the left planetary gear is meshed with the left sun gear, the right planetary gear is meshed with the right sun gear, and the left planetary gear is meshed with the right planetary gear; the double planetary gear ring is fixedly arranged on the outer circle of the double planetary gear carrier, and is meshed with the fixed axis gear reduction coupling mechanism.

[0016] Further, the fixed-axis gear reduction mechanism includes a gear shaft, a first fixed-axis reduction gear, a second fixed-axis reduction gear, and a fixed-axis reduction gear;

[0017] The gear shaft is arranged in parallel with the motor output shaft; the fixed-axis reduction gear is fixed at both ends of the gear shaft and is transmission-connected to the single planetary gear coupling mechanism on the corresponding side; the first fixed-axis reduction gear is rotationally arranged between the two motors, and the second fixed-axis reduction gear is arranged in the middle of the gear shaft and meshes with the first fixed-axis reduction gear; the double planetary gear differential coupling mechanism is transmission-connected to the second fixed-axis reduction gear through the first fixed-axis reduction gear.

[0018] Furthermore, the electric drive mechanism also includes a motor control module and a power battery module connected to the motor, the motor control module and the power battery module are arranged on one side of the motor, and the fixed-axis gear reduction coupling mechanism is arranged in parallel on the other side of the motor.

[0019] Furthermore, the working mode of the dual-motor coupled transmission device for tracked vehicles is controlled accordingly according to the working conditions, and the control method is as follows:

[0020] Parking condition: Both motors stop working, all brakes are disengaged, the transmission mechanism is in neutral, there is no power transmission, and the vehicle is parked or idling;

[0021] Forward straight driving condition: Both motors are in driving state. In the two two-speed planetary reduction mechanisms, when the brakes on the second-stage sun gear of the reduction gear are disengaged, the brakes on the outer planetary carriers of the two-speed reduction gears are engaged, the two-speed planetary reduction mechanisms are in low gear and travel at low speed. When the brakes on the second-stage sun gear of the reduction gear are engaged, the brakes on the outer planetary carriers of the two-speed reduction gears are engaged, the two-speed planetary reduction mechanisms are in high gear and travel at high speed.

[0022] Reverse driving condition: Both motors are in reverse driving state, when the brakes on the secondary sun gear of the deceleration are disengaged, the brakes on the two-speed outer planetary carriers are engaged, the two-speed planetary reduction mechanism is in low gear, and the vehicle travels at low speed; when the brakes on the secondary sun gear of the deceleration are engaged, the brakes on the two-speed outer planetary carriers are disengaged, the two-speed planetary reduction mechanism is in high gear, and the vehicle travels at high speed;

[0023] Center steering condition: one side of the power output is the forward condition and the other side of the power output is the reverse driving condition. Both motors are in the driving state, but the speed directions of the two motors are opposite.

[0024] Small radius steering condition: one side of the track mechanism is in braking state, the other side of the track mechanism is in driving state, the motor on the braking side is in generating state, the motor on the driving side is in driving state, and in the two-speed planetary reduction mechanism on the driving side, when the brake on the second-stage sun gear of the reduction gear is disengaged, the brake on the two-speed outer planetary carrier is engaged, the two-speed planetary reduction mechanism is in low gear, and low-speed steering; when the brake on the second-stage sun gear of the reduction gear is engaged, the brake on the two-speed outer planetary carrier is disengaged, the two-speed planetary reduction mechanism is in high gear, and high-speed steering is achieved.

[0025] The beneficial effects of the present invention are:

[0026] 1. In the present invention, the two motors use the planetary gear mechanism as the transmission body to realize the flexible power distribution of the two motors when turning. The planetary gears are used for power coupling, the single planetary gear coupling mechanism on both sides and the fixed axis reduction coupling mechanism can realize the steering power reflux, which can not only reduce energy consumption but also reduce the power level of the motor.

[0027] 2. The transmission system of the present invention is arranged symmetrically as a whole, has a compact structure, good processability, and is convenient for the design of steering control strategies.

[0028] 3. The two motors in the present invention adopt a high-speed design, which is beneficial to improving the power density of the motors. At the same time, there are two-speed reduction mechanisms on both sides, which can achieve multi-stage differential output on both sides.

[0029] Other advantages, objectives and features of the present invention will be described in the following description to some extent, and to some extent, will be obvious to those skilled in the art based on the following examination and study, or can be taught from the practice of the present invention. The objectives and other advantages of the present invention can be realized and obtained through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0030] In order to make the purpose, technical solutions and advantages of the present invention more clear, the present invention will be described in detail below in conjunction with the accompanying drawings, wherein:

[0031] Figure 1 This is a schematic diagram of the dual-motor coupling transmission device for tracked vehicles of the present invention.

[0032] Figure 2 It is a schematic diagram of the power flow of the dual-motor coupled transmission device for a tracked vehicle of the present invention under straight-line operation conditions.

[0033] Figure 3It is a schematic diagram of the power flow in the small radius turning condition of the dual-motor coupled transmission device for tracked vehicles of the present invention.

[0034] Figure numerals: 1-motor control module; 2-power battery module; 3-double planetary gear ring; 4-double planetary gear carrier; 5-right planetary gear; 6-left planetary gear; 7-right sun gear; 8-left sun gear; 9-first fixed-axis reduction gear; 10-second fixed-axis reduction gear; 11-gear shaft; 12a(b)-motor; 13a(b)-brake; 14a(b)-reduction secondary sun gear; 15a(b)-brake; 16a(b)-two-speed reduction gear ring; 17a(b)-two-speed reduction outer planet carrier; 18a(b)-two gear reduction inner planetary carrier; 19a(b)- first-stage reduction sun gear; 20a(b)- second-stage reduction outer planetary gear; 21a(b)- second-stage reduction inner planetary gear; 22a(b)- second-stage reduction output shaft; 23a(b)- single planetary row gear ring; 24a(b)- single planetary row planetary carrier; 25a(b)- single planetary row sun gear; 26a(b)- single planetary row sun gear shaft; 27a(b)- fixed shaft reduction gear; 28a(b)- power output shaft; 29a(b)- single planetary row planetary gear; 30a(b)- motor output shaft. DETAILED DESCRIPTION

[0035] The following describes the embodiments of the present invention by specific examples, and those skilled in the art can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The present invention can also be implemented or applied through other different specific embodiments, and the details in this specification can also be modified or changed in various ways based on different viewpoints and applications without departing from the spirit of the present invention. It should be noted that the illustrations provided in the following embodiments only illustrate the basic concept of the present invention in a schematic manner, and the following embodiments and features in the embodiments can be combined with each other without conflict.

[0036] Among them, the drawings are only used for illustrative explanations, and they only represent schematic diagrams rather than actual pictures, and should not be understood as limitations on the present invention. In order to better illustrate the embodiments of the present invention, some parts of the drawings may be omitted, enlarged or reduced, and do not represent the size of actual products. For those skilled in the art, it is understandable that some well-known structures and their descriptions in the drawings may be omitted.

[0037] The same or similar numbers in the drawings of the embodiments of the present invention correspond to the same or similar parts; in the description of the present invention, it should be understood that if the terms "upper", "lower", "left", "right", "front", "rear", etc. indicate the orientation or position relationship, they are based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation. Therefore, the terms describing the position relationship in the drawings are only used for illustrative purposes and cannot be understood as limiting the present invention. For ordinary technicians in this field, the specific meanings of the above terms can be understood according to specific circumstances.

[0038] See also Figure 1 , is a dual-motor coupling transmission device for a tracked vehicle, comprising two electric drive mechanisms and a fixed-axis gear reduction coupling mechanism arranged symmetrically on the left and right, each electric drive mechanism correspondingly driving one track mechanism; the electric drive mechanism comprises a motor 12, a speed change mechanism, and a single planetary gear coupling mechanism which are sequentially connected in transmission; a double planetary gear differential coupling mechanism is arranged between the two motors 12, one end of the output shaft of the speed change mechanism is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; the output shafts of the two speed change mechanisms are coupled through the double planetary gear differential coupling mechanism; the two ends of the fixed-axis gear reduction coupling mechanism are respectively coupled to the two single planetary gear coupling mechanisms, and at the same time, the middle part of the fixed-axis gear reduction coupling mechanism is coupled to the double planetary gear differential coupling mechanism.

[0039] The speed change mechanism is a two-speed planetary reduction mechanism, including a two-speed reduction inner planet carrier 18, a two-speed reduction outer planet carrier 17, a first-stage reduction sun gear 19, a second-stage reduction sun gear 14, inner planetary gears, outer planetary gears, a two-speed reduction ring gear 16 and two brakes 15; the outer planetary gears are arranged on the two-speed reduction outer planet carrier 17, the inner planetary gears are arranged on the two-speed reduction inner planet carrier 18, the two-speed reduction outer planet carrier 17 is fixedly connected to the two-speed reduction inner planet carrier 18; the motor output shaft is connected to the first-stage reduction sun gear 19, the inner planetary gears are connected to the reduction The first-speed sun gear 19 is meshed with the outer planetary gear 14; the inner side of the outer planetary gear is meshed with the inner planetary gear and the second-speed sun gear 14 at the same time, and the outer side is meshed with the two-speed reduction gear ring 16 for transmission; a two-speed reduction output shaft 22 is fixedly arranged on the two-speed reduction gear ring 16, one end of the two-speed reduction output shaft 22 is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; two brakes 15 are respectively arranged on the two-speed reduction outer planetary carrier 17 and the second-speed sun gear 14, and two-speed shifting is realized by braking switching with the two brakes 15.

[0040] The single planet row coupling mechanism includes a planet row sun gear, a single planet row planet carrier 24, a single planet row planet gear 29, and a single planet row ring gear 23; the single planet row ring gear 23 is fixedly connected to the two-speed reduction output shaft 22; the single planet row planet gear 29 is arranged on the single planet row planet carrier 24 and meshes with the single planet row ring gear 23; one end of the single planet row sun gear 25 is meshed with the single planet row planet gear 29, and the other end is meshed with the fixed axis gear reduction coupling mechanism; the single planet row planet carrier 24 is fixedly connected with a power output shaft 28, and the crawler mechanism is driven by the power output shaft 28.

[0041] The double planetary gear differential coupling mechanism comprises a left sun gear 8, a left planetary gear 6, a right sun gear 7, a right planetary gear 5, a double planetary gear carrier 4 and a double planetary gear ring 3; the left sun gear 8 and the right sun gear 7 are arranged left and right, and are respectively fixedly connected to the two-speed reduction output shaft 22 on the corresponding side; the left planetary gear 6 and the right planetary gear 5 are rotatably arranged in the double planetary gear carrier 4, and the left planetary gear 6 is meshed with the left sun gear 8, the right planetary gear 5 is meshed with the right sun gear 7, and the left planetary gear 6 is meshed with the right planetary gear 5; the double planetary gear ring 3 is fixedly arranged on the outer circle of the double planetary gear carrier 4, and is meshed with the fixed axis gear reduction coupling mechanism.

[0042] The fixed-axis gear reduction mechanism includes a gear shaft 11, a first fixed-axis reduction gear 9, a second fixed-axis reduction gear 10, and a fixed-axis reduction gear 27; the gear shaft 11 is arranged in parallel with the motor output shaft; the fixed-axis reduction gear 27 is fixedly arranged at both ends of the gear shaft 11, and is transmission-connected with the single planetary gear coupling mechanism on the corresponding side; the first fixed-axis reduction gear 9 is rotationally arranged between the two motors 12, and the second fixed-axis reduction gear 10 is arranged in the middle of the gear shaft 11 and meshes with the first fixed-axis reduction gear 9; the double planetary gear differential coupling mechanism is transmission-connected with the second fixed-axis reduction gear 10 through the first fixed-axis reduction gear 9.

[0043] The electric drive mechanism also includes a motor control module 1 and a power battery module 2 connected to the motor 12 . The motor control module 1 and the power battery module 2 are arranged on one side of the motor 12 , and the fixed axis gear reduction coupling mechanism is arranged in parallel on the other side of the motor 12 .

[0044] In the present invention, the power output by the motors on both sides can be transmitted to the final reduction mechanisms on the left and right sides after a fixed reduction ratio, or it can be transmitted to the final reduction gears on the left and right sides after being reduced by two gears through a reduction mechanism and a coupling mechanism, and finally power coupling is performed through the single planetary gear mechanisms on both sides and output through the planetary carrier.

[0045] The working mode of the dual-motor coupling transmission device for tracked vehicles is controlled accordingly according to the working conditions. The control method is shown in Table 1:

[0046] Table 1 Working mode of the present invention

[0047]

[0048] Parking condition: the two motors 12 stop working, all brakes are disengaged, the speed change mechanism is in neutral, there is no power transmission, and the vehicle is parked or idling;

[0049] Forward straight driving condition: both motors 12 are in driving state. In the two two-speed planetary reduction mechanisms, when the brakes 15 on the secondary reduction sun gear 14 are disengaged, the brakes 15 on the two-speed reduction outer planetary carriers 17 are engaged, the two-speed planetary reduction mechanisms are in low gear and travel at low speed. When the brakes 15 on the secondary reduction sun gear 14 are engaged, the brakes 15 on the two-speed reduction outer planetary carriers 17 are engaged, the two-speed planetary reduction mechanisms are in high gear and travel at high speed.

[0050] Reverse driving condition: both motors 12 are in reverse driving state, when the brakes 15 on the secondary reduction sun gear 14 are disengaged, the brakes 15 on the two-speed reduction outer planetary carrier 17 are engaged, the two-speed planetary reduction mechanism is in low gear, and the vehicle is traveling at a low speed; when the brakes 15 on the secondary reduction sun gear 14 are engaged, the brakes 15 on the two-speed reduction outer planetary carrier 17 are disengaged, the two-speed planetary reduction mechanism is in high gear, and the vehicle is traveling at a high speed;

[0051] Center steering condition: one side of the power output is the forward condition and the other side of the power output is the reverse driving condition, both motors 12 are in the driving state, but the rotational speeds of the two motors 12 are in opposite directions;

[0052] Small radius steering condition: one side of the crawler mechanism is in braking state, the other side of the crawler mechanism is in driving state, the motor 12 on the braking side is in generating state, the motor 12 on the driving side is in driving state, and in the two-speed planetary reduction mechanism on the driving side, when the brake 15 on the second-stage reduction sun gear 14 is disengaged, the brake 15 on the two-stage reduction outer planetary carrier 17 is engaged, the two-stage planetary reduction mechanism is in low gear, and low-speed steering is performed; when the brake 15 on the second-stage reduction sun gear 14 is engaged, the brake 15 on the two-stage reduction outer planetary carrier 17 is disengaged, the two-stage planetary reduction mechanism is in high gear, and high-speed steering is performed.

[0053] Figure 2The power flow diagram of direct driving is as follows: the power flows into the two-speed planetary reduction mechanism through the motor 12a(b) via the first-stage reduction sun gear 19a(b), and the power flows out of the two-speed planetary reduction mechanism through two paths, one of which flows into the single planetary gear ring 23a(b) on one side through the two-speed reduction ring gear 16a(b), and is output through the power output shaft 28a(b); the other flows into the double planetary gear differential coupling mechanism through the two-speed reduction output shaft 22a(b), the left sun gear 8 and the right sun gear 7, and then flows into the single planetary gear coupling mechanisms on both sides through the double planetary gear ring 3, the first fixed axis reduction gear 9, the second fixed axis reduction gear 10 and the fixed axis reduction gear 27a(b) of the double planetary gear differential coupling mechanism, and finally outputs power through the power output shaft 28a(b).

[0054] Figure 3 Schematic diagram of steering power flow. Taking the left side braking and the right side driving as an example, the steering return power of the left track can be efficiently returned to the right track through the steering power coupling mechanism. There are two paths for this power flow, one of which is through the power output shaft 28a through the first fixed axis reduction gear 9, the second fixed axis reduction gear 10 and the fixed axis reduction gear 27a (b) into the double planetary gear differential coupling mechanism, flows out from the right sun gear 7, flows into the right single planetary gear coupling mechanism through the two-speed reduction output shaft 22b, and is output through the power output shaft 28b;

[0055] Another power recovery path is from the left power output shaft 28a to the power battery module 2, where the power flows from the power output shaft 28a into the left single planetary gear coupling mechanism, from the single planetary gear ring 23a to the two-speed reduction inner planet carrier 18a, and then from the first-stage reduction sun gear 19a to the motor 12a, and finally to the power battery module 2. The output power flow direction of the motor 12b is the same as the power flow direction of the straight-running condition.

[0056] Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention rather than to limit it. Although the present invention has been described in detail with reference to the preferred embodiments, those skilled in the art should understand that the technical solution of the present invention can be modified or replaced by equivalents without departing from the purpose and scope of the technical solution, which should be included in the scope of the claims of the present invention.

Claims

1. A dual-motor coupling transmission device for a tracked vehicle, characterized in that: It includes two electric drive mechanisms and fixed-axis gear reduction coupling mechanisms arranged symmetrically on the left and right, and each electric drive mechanism drives a corresponding track mechanism; the electric drive mechanism includes a motor, a speed change mechanism, and a single planetary gear coupling mechanism connected in sequence; a double planetary gear differential coupling mechanism is provided between the two motors, one end of the output shaft of the speed change mechanism is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; the output shafts of the two speed change mechanisms are coupled through the double planetary gear differential coupling mechanism; The two ends of the fixed-axis gear reduction coupling mechanism are respectively coupled to the two single planetary gear coupling mechanisms, and at the same time, the middle part of the fixed-axis gear reduction coupling mechanism is coupled to the double planetary gear differential coupling mechanism; The speed change mechanism is a two-speed planetary reduction mechanism, including a two-speed reduction inner planet carrier, a two-speed reduction outer planet carrier, a first-stage reduction sun gear, a second-stage reduction sun gear, an inner planet gear, an outer planet gear, a two-speed reduction ring gear and two brakes; The outer planetary gear is arranged on the two-speed reduction outer planetary carrier, the inner planetary gear is arranged on the two-speed reduction inner planetary carrier, the two-speed reduction outer planetary carrier is fixedly connected to the two-speed reduction inner planetary carrier; the motor output shaft is connected to the first-stage reduction sun gear, and the inner planetary gear is meshed with the first-stage reduction sun gear; the inner side of the outer planetary gear is meshed with the inner planetary gear and the second-stage reduction sun gear at the same time, and the outer side is meshed with the two-speed reduction gear ring for transmission; the two-speed reduction gear ring is fixedly provided with a two-speed reduction output shaft, one end of the two-speed reduction output shaft is connected to the single planetary gear coupling mechanism, and the other end is connected to the double planetary gear differential coupling mechanism; The two brakes are respectively arranged on the two-speed reduction outer planetary carrier and the secondary reduction sun gear, and the two-speed shifting is realized by braking switching of the two brakes; The single planet row coupling mechanism comprises a single planet row sun gear, a single planet row planet carrier, a single planet row planet gear and a single planet row ring gear; The single planetary gear ring is fixedly connected to the two-speed reduction output shaft; the single planetary gear is arranged on the single planetary gear carrier and meshes with the single planetary gear ring; one end of the single planetary gear sun gear meshes with the single planetary gear, and the other end meshes with the fixed axis gear reduction coupling mechanism; the single planetary gear carrier is fixedly connected with a power output shaft, and the crawler mechanism is driven by the power output shaft; The double planetary gear differential coupling mechanism comprises a left sun gear, a left planetary gear, a right sun gear, a right planetary gear, a double planetary gear carrier, and a double planetary gear ring; The left sun gear and the right sun gear are arranged on the left and right sides, and are respectively fixedly connected to the two-speed reduction output shafts on the corresponding sides; the left planetary gear and the right planetary gear are rotatably arranged in the double planetary gear carrier, and the left planetary gear is meshed with the left sun gear, the right planetary gear is meshed with the right sun gear, and the left planetary gear is meshed with the right planetary gear; the double planetary gear ring is fixedly arranged on the outer circle of the double planetary gear carrier, and is meshed with the fixed axis gear reduction coupling mechanism; The fixed-axis gear reduction coupling mechanism includes a gear shaft, a first fixed-axis reduction gear, a second fixed-axis reduction gear, and a fixed-axis reduction gear; The gear shaft is arranged in parallel with the motor output shaft; the fixed-axis reduction gear is fixed at both ends of the gear shaft and is transmission-connected to the single planetary gear coupling mechanism on the corresponding side; the first fixed-axis reduction gear is rotationally arranged between the two motors, and the second fixed-axis reduction gear is arranged in the middle of the gear shaft and meshes with the first fixed-axis reduction gear; the double planetary gear differential coupling mechanism is transmission-connected to the second fixed-axis reduction gear through the first fixed-axis reduction gear.

2. The dual-motor coupling transmission device for a tracked vehicle according to claim 1, characterized in that: The electric drive mechanism further comprises a motor control module and a power battery module connected to the motor. The motor control module and the power battery module are arranged on one side of the motor, and the fixed-axis gear reduction coupling mechanism is arranged in parallel on the other side of the motor.

3. The dual-motor coupling transmission device for a tracked vehicle according to claim 1, characterized in that: The working mode of the dual-motor coupled transmission device for tracked vehicles is controlled accordingly according to the working conditions, and the control method is as follows: Parking condition: Both motors stop working, all brakes are disengaged, the transmission mechanism is in neutral, there is no power transmission, and the vehicle is parked or idling; Forward straight driving condition: Both motors are in driving state. In the two two-speed planetary reduction mechanisms, when the brakes on the second-stage sun gear of the reduction gear are disengaged, the brakes on the outer planetary carriers of the two-speed reduction gears are engaged, the two-speed planetary reduction mechanisms are in low gear and travel at low speed. When the brakes on the second-stage sun gear of the reduction gear are engaged, the brakes on the outer planetary carriers of the two-speed reduction gears are engaged, the two-speed planetary reduction mechanisms are in high gear and travel at high speed. Reverse driving condition: Both motors are in reverse driving state, when the brakes on the secondary sun gear of the deceleration are disengaged, the brakes on the two-speed outer planetary carriers are engaged, the two-speed planetary reduction mechanism is in low gear, and the vehicle travels at low speed; when the brakes on the secondary sun gear of the deceleration are engaged, the brakes on the two-speed outer planetary carriers are disengaged, the two-speed planetary reduction mechanism is in high gear, and the vehicle travels at high speed; Center steering condition: one side of the power output is the forward condition and the other side of the power output is the reverse driving condition. Both motors are in the driving state, but the speed directions of the two motors are opposite. Small radius steering condition: one side of the crawler mechanism is in braking state, the other side of the crawler mechanism is in driving state, the motor on the braking side is in generating state, the motor on the driving side is in driving state, in the two-speed planetary reduction mechanism on the driving side, when the brake on the secondary reduction sun gear is disengaged, the brake on the two-speed reduction outer planetary carrier is engaged, the two-speed planetary reduction mechanism is in low gear, and low-speed steering is performed; When the brake on the secondary sun gear of the reduction gear is engaged, the brake on the outer planetary carrier of the two-speed reduction gear is disengaged, and the two-speed planetary reduction mechanism is in high gear and turns at high speed.

Images