A four-section and multi-working mode continuously variable transmission device and tractor

Abstract

The present invention provides a four-section and multi-working mode continuously variable transmission device and a tractor. A four-section and multi-working mode continuously variable transmission device, wherein the engine is connected to the first transmission shaft; the first transmission shaft is in driving connection with the second transmission shaft; the sixth clutch is installed on the second transmission shaft, and the planetary confluence mechanism is respectively in driving connection with the second transmission shaft, the third transmission shaft, and the fourth transmission shaft; the first clutch and the second clutch are both installed on the third transmission shaft; the third clutch and the fourth clutch are both installed on the fourth transmission shaft; the third transmission shaft and the fourth transmission shaft are both in driving connection with the fifth transmission shaft; the motor is in driving connection with the fifth clutch and the planetary confluence mechanism.

Description

Technical Field

[0001] The invention relates to the technical field of tractor speed change, and in particular to a four-section and multi-working mode continuously variable speed change device and a tractor. Background Art

[0002] The continuously variable transmission technology of agricultural tractors used to use hydrostatic transmission units to achieve stepless speed regulation. Recently, there has been a gearbox technology that uses generators and motors to achieve stepless speed regulation, with a single or two-segment speed regulation section. In order to achieve a wide range of stepless speed regulation, the motor uses a high-speed motor with a very wide working speed range. However, the high-speed motor brings high speed input to the tractor gearbox, resulting in low gearbox transmission efficiency, reduced reliability, and difficulty in controlling abnormal noise in the transmission system. Summary of the invention

[0003] The technical problem to be solved by the present invention is to provide a four-section and multi-working mode continuously variable transmission device and a tractor in view of the deficiencies in the prior art.

[0004] The technical solution of the present invention to solve the above technical problems is as follows: A four-section and multi-working mode continuously variable transmission device, comprising: an engine, a first transmission shaft, a second transmission shaft, a third transmission shaft, a fourth transmission shaft, a fifth transmission shaft, a planetary confluence mechanism, a first clutch for stepped speed change, a second clutch for stepped speed change, a third clutch for stepped speed change, a fourth clutch for stepped speed change, a fifth clutch for mode switching, a sixth clutch for mode switching, and an electric motor, wherein the engine is connected to the first transmission shaft; the first transmission shaft is transmission-connected to the second transmission shaft; the sixth clutch is installed on the second transmission shaft, and the planetary confluence mechanism is transmission-connected to the second transmission shaft, the third transmission shaft, and the fourth transmission shaft respectively; the first clutch and the second clutch are both installed on the third transmission shaft; the third clutch and the fourth clutch are both installed on the fourth transmission shaft; the third transmission shaft and the fourth transmission shaft are both transmission-connected to the fifth transmission shaft; the electric motor is transmission-connected to the fifth clutch and the planetary confluence mechanism.

[0005] The beneficial effects of the technical solution of the present invention are: using a planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, and the stepless speed regulation range in each section is reduced. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise. At the same time, the fifth clutch and the sixth clutch are set on the planetary mechanism as two mode switching clutches, so that the entire transmission system has four working modes, providing the best fuel efficiency and maximum torque output under various working conditions.

[0006] Furthermore, a seventh clutch is installed on the second transmission shaft.

[0007] The beneficial effects of adopting the above further technical solution are: removing the ninth clutch in the power reversing, automatically switching to the pure electric drive continuously variable transmission mode or the oil-electric series hybrid continuously variable transmission mode when reversing, locking the sixth clutch, and using the reverse rotation of the electric motor to achieve reversing.

[0008] Furthermore, an eighth clutch is installed on the first transmission shaft, and a ninth clutch is installed on the second transmission shaft.

[0009] The beneficial effect of adopting the above further technical solution is that it is easy to realize the reversing function with heavy load, so that the rated power of the vehicle can be exerted when reversing.

[0010] Furthermore, the planetary confluence mechanism is a NW planetary confluence mechanism.

[0011] The beneficial effects of adopting the above further technical solution are: using the planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, narrowing the stepless speed regulation range in each section. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise.

[0012] Furthermore, the electric motor is connected to a power storage device.

[0013] The beneficial effect of adopting the above further technical solution is that it is convenient for the electric motor to directly draw electricity from the power storage device to drive the vehicle.

[0014] Furthermore, the first transmission shaft is connected to a generator, and the generator is connected to the power storage device and the electric motor respectively.

[0015] The beneficial effects of adopting the above further technical solution are: the engine drives the generator, the motor can draw power from the generator, can draw power from the generator and the power storage device at the same time, and can draw power from the power storage device alone to drive the vehicle, and the vehicle can be reversed by reversing the motor. The excess electric energy generated by the generator can be stored in the power storage device.

[0016] Furthermore, the planetary confluence mechanism is equipped with a ring gear of a secondary planetary gear, and the electric motor is drivingly connected to the ring gear of the secondary planetary gear.

[0017] Furthermore, the planetary confluence mechanism is equipped with a sun gear of a primary planetary gear, and the second transmission shaft is drivingly connected to the sun gear of the primary planetary gear.

[0018] Furthermore, the motor has forward and reverse rotation functions.

[0019] The beneficial effect of adopting the above further technical solution is that the vehicle can be reversed by reversing the motor.

[0020] In addition, the present invention also provides a tractor, comprising a four-section and multi-working mode continuously variable transmission device as described in any one of the above.

[0021] The beneficial effects of the technical solution of the present invention are: using a planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, and the stepless speed regulation range in each section is reduced. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise. At the same time, the fifth clutch and the sixth clutch are set on the planetary mechanism as two mode switching clutches, so that the entire transmission system has four working modes, providing the best fuel efficiency and maximum torque output under various working conditions.

[0022] Advantages of additional aspects of the present invention will be given in part in the following description, and in part will be obvious from the following description, or will be learned through practice of the present invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 This is one of the structural schematic diagrams of a four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0024] Figure 2 The second structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0025] Figure 3 The third structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0026] Figure 4 The fourth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0027] Figure 5 The fifth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0028] Figure 6 The sixth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0029] Figure 7 The seventh structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0030] Figure 8 The eighth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0031] Fig. 9 The ninth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0032] Fig.10 The tenth structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0033] Fig.11 The eleventh structural schematic diagram of the four-section and multi-working mode continuously variable transmission device provided in an embodiment of the present invention.

[0034] Explanation of the accompanying drawings: 1. engine; 2. first transmission shaft; 3. second transmission shaft; 4. third transmission shaft; 5. fourth transmission shaft; 6. fifth transmission shaft; 7. planetary convergence mechanism; 8. first clutch; 9. second clutch; 10. third clutch; 11. fourth clutch; 12. fifth clutch; 13. sixth clutch; 14. electric motor; 15. seventh clutch; 16. eighth clutch; 17. ninth clutch; 18. power storage device; 19. generator. DETAILED DESCRIPTION

[0035] The principles and features of the present invention are described below in conjunction with the accompanying drawings. The examples given are only used to explain the present invention but not to limit the scope of the present invention.

[0036] like Figures 1 to 11As shown, an embodiment of the present invention provides a four-section and multi-working mode continuously variable transmission device, including: an engine 1, a first transmission shaft 2, a second transmission shaft 3, a third transmission shaft 4, a fourth transmission shaft 5, a fifth transmission shaft 6, a planetary confluence mechanism 7, a first clutch 8 for step-by-step speed change, a second clutch 9 for step-by-step speed change, a third clutch 10 for step-by-step speed change, a fourth clutch 11 for step-by-step speed change, a fifth clutch 12 for mode switching, a sixth clutch 13 for mode switching, and an electric motor 14, wherein the engine 1 is connected to the first transmission shaft 2; the first transmission shaft 2 is connected to the first transmission shaft 2; the second transmission shaft 2 is connected to the first transmission shaft 2; the third clutch 10 is connected to the first transmission shaft 2; the fourth clutch 11 is connected to the first transmission shaft 2; the fifth clutch 12 is connected to the first transmission shaft 2; the fifth clutch 13 ... The second transmission shaft 3 is transmission connected; the sixth clutch 13 is installed on the second transmission shaft 3, and the planetary confluence mechanism 7 is transmission connected with the second transmission shaft 3, the third transmission shaft 4, and the fourth transmission shaft 5 respectively; the first clutch 8 and the second clutch 9 are both installed on the third transmission shaft 4; the third clutch 10 and the fourth clutch 11 are both installed on the fourth transmission shaft 5; the third transmission shaft 4 and the fourth transmission shaft 5 are both transmission connected with the fifth transmission shaft 6; the motor 14 is transmission connected with the fifth clutch 12 and the planetary confluence mechanism 7.

[0037] The beneficial effects of the technical solution of the present invention are: using a planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, and the stepless speed regulation range in each section is reduced. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise. At the same time, the fifth clutch and the sixth clutch are set on the planetary mechanism as two mode switching clutches, so that the entire transmission system has four working modes, providing the best fuel efficiency and maximum torque output under various working conditions.

[0038] The transmission connection of the above-mentioned components can be connected through gear transmission. The motor can be a low-speed motor. In the industry, a motor with a rated speed greater than 4000 rpm is generally defined as a high-speed motor, and a motor with a rated speed less than or equal to 4000 rpm is defined as a low-speed motor.

[0039] Figures 1 to 6 The dotted line in the figure is the work or power transfer path, which is transmitted through gears on the left and electricity on the right.

[0040] This technical route uses the NW planetary confluence mechanism (planetary confluence mechanism) in conjunction with multiple mechanical and hydraulic shift mechanisms. By engaging the four clutches A, B, C, and D (the first clutch, the second clutch, the third clutch, and the fourth clutch), four continuously variable speed sections are achieved, narrowing the continuously variable speed range within each section. At the same time, two mode switching clutches MC and EC (the fifth clutch and the sixth clutch) are set on the NW planetary mechanism (planetary confluence mechanism), so that the entire transmission system can work in the following four modes:

[0041] Purely mechanical stepped speed mode, suitable for medium loads and highest transmission efficiency.

[0042] Pure electric drive continuously variable speed mode, suitable for starting and light load transfer, with maximum fuel efficiency.

[0043] The oil-electric series hybrid continuously variable transmission mode is suitable for starting and light load transfer (when the battery power is low), medium load operation and transportation, and has higher fuel efficiency.

[0044] The oil-electric parallel hybrid continuously variable transmission mode is suitable for heavy-load operations and the highest torque output.

[0045] Among them, the continuously variable speed section is divided as follows: there are four stepped speed zones at the rear end, which are controlled by four clutches ABCD (first clutch, second clutch, third clutch and fourth clutch).

[0046] ABCD (first clutch, second clutch, third clutch and fourth clutch) are four mechanical stepped speed changers, providing four different gears, so that the speed range of the front-end continuously variable transmission changes.

[0047] In order to reduce the stepless speed range within each section, the speed range of domestic agricultural tractors is stipulated to be less than 40km / h. The more sections there are, the smaller the speed range covered by each section. Therefore, the stepless speed range within each section is reduced.

[0048] The EC clutch (fifth clutch 12) is used to lock the motor M (motor 14) to prevent it from rotating, because the motor (motor 14) cannot work normally when the speed is close to 0, and an additional clutch is required to lock it at 0. Among them, locking refers to engaging the clutch.

[0049] like Figures 1 to 11 As shown, the arrows in the figure represent the transmission direction and transmission trajectory of power and electric energy.

[0050] like Figures 1 to 10 As shown, further, an eighth clutch 16 is installed on the first transmission shaft 2, and a ninth clutch 17 is installed on the second transmission shaft 3.

[0051] The beneficial effect of adopting the above further technical solution is that it is easy to realize the reversing function with heavy load, so that the rated power of the vehicle can be exerted when reversing.

[0052] Among them, the eighth clutch 16 is a forward gear clutch, and the ninth clutch 17 is a reverse gear clutch.

[0053] like Fig.11 As shown, as an alternative to the above embodiment, a seventh clutch 15 is installed on the second transmission shaft 3 .

[0054] The beneficial effects of adopting the above further technical solution are: removing the ninth clutch in the power reversing, automatically switching to the pure electric drive continuously variable transmission mode or the oil-electric series hybrid continuously variable transmission mode when reversing, locking the sixth clutch, and using the reverse rotation of the electric motor to achieve reversing.

[0055] If there is no need to cope with high-load reversing conditions, the route of the above embodiment can be simplified by removing the reverse clutch (ninth clutch) in the power reversing, automatically switching to the pure electric drive continuously variable transmission mode or the oil-electric series hybrid continuously variable transmission mode when reversing, locking the MC clutch (sixth clutch), and using the reverse rotation of the electric motor M to achieve reversing.

[0056] In this structure, the function of the F clutch (the seventh clutch 15) is only to disconnect the engine torque input.

[0057] The seventh clutch 15 is a forward gear clutch.

[0058] like Figures 1 to 11 As shown, further, the planetary confluence mechanism 7 is a NW planetary confluence mechanism.

[0059] The beneficial effects of adopting the above further technical solution are: using the planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, narrowing the stepless speed regulation range in each section. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise.

[0060] like Figures 1 to 11 As shown, further, the electric motor 14 is connected to a power storage device 18 .

[0061] The beneficial effect of adopting the above further technical solution is that it is convenient for the electric motor to directly draw electricity from the power storage device to drive the vehicle.

[0062] The power storage device may be a battery, a capacitor or other power storage devices using physical or chemical principles.

[0063] like Figures 1 to 11As shown, further, the first transmission shaft 2 is connected to a generator 19, and the generator 19 is connected to the power storage device 18 and the motor 14 respectively.

[0064] The beneficial effects of adopting the above further technical solution are: the engine drives the generator, the motor can draw power from the generator, can draw power from the generator and the power storage device at the same time, and can draw power from the power storage device alone to drive the vehicle, and the vehicle can be reversed by reversing the motor. The excess electric energy generated by the generator can be stored in the power storage device.

[0065] like Figures 1 to 11 As shown, further, the planetary confluence mechanism 7 is equipped with a ring gear of a secondary planetary gear, and the electric motor 14 is drivingly connected to the ring gear of the secondary planetary gear.

[0066] like Figures 1 to 11 As shown, further, the planetary confluence mechanism 7 is equipped with a sun gear of a primary planetary gear, and the second transmission shaft 3 is drivingly connected to the sun gear of the primary planetary gear.

[0067] like Figures 1 to 11 As shown, further, the motor 14 has forward and reverse rotation functions.

[0068] The beneficial effect of adopting the above further technical solution is that the vehicle can be reversed by reversing the motor.

[0069] The embodiment of the present invention provides a four-section and multi-working mode continuously variable transmission device, which can be a four-section multi-mode continuously variable transmission system, which can reduce the stepless speed regulation range in each section, better compatible with low-speed motors, improve the efficiency and reliability of the transmission system, and reduce noise. Four working modes are provided at the same time.

[0070] 1. When the engine 1 is started and the clutch EC (fifth clutch) is locked (engaged), the vehicle (which can be a tractor) is in a pure mechanical transmission mode, and the power transmission route is as follows:

[0071] Power reversing section:

[0072] like Figure 2 As shown, clutch F (seventh clutch) is locked, forward gear.

[0073] like Figure 3 As shown, clutch R (ninth clutch) is locked and in reverse gear.

[0074] Continuously variable speed section:

[0075] The EC clutch (fifth clutch) is locked and the continuously variable transmission does not work.

[0076] Section mechanical speed change section:

[0077] like Figure 4 As shown, clutch A (first clutch) is locked, section A.

[0078] like Figure 5 As shown, clutch B (second clutch) is locked, section B.

[0079] like Figure 6 As shown, the C clutch (third clutch) is locked, section C.

[0080] like Figure 7 As shown, the D clutch (fourth clutch) is locked, section D.

[0081] Among them, after the EC clutch (fifth clutch) is locked, the speed of the motor M (motor) is forced to be locked at 0 rpm, and the motor M will not participate in the speed regulation.

[0082] 2. When the engine is turned off and the clutch MC (sixth clutch) is locked, the vehicle is in pure electric drive mode, and the power transmission route is as follows:

[0083] Power reversing section:

[0084] The clutch MC (sixth clutch) is locked and the power shifting section does not work (after the clutch MC is locked, the speed of the power shifting section is locked to 0).

[0085] Continuously variable speed section:

[0086] like Figure 8 As shown, the electric motor M (motor 14 ) directly draws power from the power storage device to drive the vehicle, and the vehicle reverses by reversing the motor (motor 14 ).

[0087] Section mechanical speed change section:

[0088] The working principle is the same as the pure mechanical speed change mode.

[0089] 3. When the engine is started and the clutch MC (sixth clutch) is locked, the vehicle is in the oil-electric series hybrid continuously variable transmission mode, and the power transmission route is as follows:

[0090] Power reversing section:

[0091] Clutch MC (sixth clutch) is locked and the power reversing section does not work.

[0092] Continuously variable speed section:

[0093] like Fig. 9As shown, the engine drives the generator D (generator 19), and the motor M (motor 14) can draw power from the generator 19, or from the generator and the power storage device at the same time, or from the power storage device alone to drive the vehicle, and the vehicle can be reversed by reversing the motor (motor 14). The excess electric energy generated by the generator D can be stored in the power storage device.

[0094] Section mechanical speed change section:

[0095] The working principle is the same as the pure mechanical speed change mode.

[0096] 4. When the engine is started and the clutches MC (sixth clutch) and EC (fifth clutch) are unlocked (disengaged), the vehicle is in the oil-electric parallel flow hybrid continuously variable transmission mode, and the power transmission route is as follows:

[0097] Power reversing section:

[0098] The working principle is the same as the pure mechanical speed change mode.

[0099] Continuously variable speed section:

[0100] like Fig.10 As shown, the engine power is divided into two paths. One path drives the generator D (generator 19), and the generated electric energy drives the motor M (motor 14), and the motor M drives the ring gear of the secondary planetary gear. The other path of power is input from the sun gear of the primary planetary gear through the F clutch (the eighth clutch), reaches the secondary planetary gear (secondary planetary gear) and merges with the power of the motor M.

[0101] By adjusting the speed of the electric motor M to increase or offset the speed of the mechanical circuit, the total output speed of the planetary mechanism (planetary confluence mechanism) can be adjusted steplessly to achieve stepless speed change.

[0102] Section mechanical speed change section:

[0103] The working principle is the same as the pure mechanical speed change mode.

[0104] The embodiment of the present invention uses a technical route and a multi-mode switching design to make the transmission system (a four-section and multi-working mode continuously variable transmission device) compatible with a low-speed motor, thereby improving the efficiency and reliability of the transmission system and reducing noise. At the same time, it provides a variety of working modes to provide optimal fuel efficiency and maximum torque output under a variety of working conditions.

[0105] In addition, the present invention also provides a tractor, comprising a four-section and multi-working mode continuously variable transmission device as described in any one of the above.

[0106] The beneficial effects of the technical solution of the present invention are: using a planetary confluence mechanism, in cooperation with multiple mechanical and hydraulic shift mechanisms, by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four stepless speed change sections, and the stepless speed regulation range in each section is reduced. Better compatibility with low-speed motors, improving the efficiency and reliability of the transmission system, and reducing noise. At the same time, the fifth clutch and the sixth clutch are set on the planetary mechanism as two mode switching clutches, so that the entire transmission system has four working modes, providing the best fuel efficiency and maximum torque output under various working conditions.

[0107] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A four-section and multi-working mode continuously variable transmission, characterized in that: include: An engine, a first transmission shaft, a second transmission shaft, a third transmission shaft, a fourth transmission shaft, a fifth transmission shaft, a planetary confluence mechanism, a first clutch for stepped speed change, a second clutch for stepped speed change, a third clutch for stepped speed change, a fourth clutch for stepped speed change, a fifth clutch for mode switching, a sixth clutch for mode switching, and an electric motor, wherein the engine is connected to the first transmission shaft; the first transmission shaft is transmission-connected to the second transmission shaft; the sixth clutch is mounted on the second transmission shaft, and the planetary confluence mechanism is transmission-connected to the second transmission shaft, the third transmission shaft, and the fourth transmission shaft respectively; the first clutch and the second clutch are both mounted on the third transmission shaft; the third clutch and the fourth clutch are both mounted on the fourth transmission shaft; the third transmission shaft and the fourth transmission shaft are both transmission-connected to the fifth transmission shaft; the electric motor is transmission-connected to the fifth clutch and the planetary confluence mechanism; an eighth clutch is mounted on the first transmission shaft, and a ninth clutch is mounted on the second transmission shaft; the planetary confluence mechanism is a NW type The planetary confluence mechanism is provided with a ring gear of a secondary planetary gear, and the motor is connected to the ring gear of the secondary planetary gear in a transmission manner; the planetary confluence mechanism is provided with a sun gear of a primary planetary gear, and the second transmission shaft is connected to the sun gear of the primary planetary gear in a transmission manner; the function of the fifth clutch is to lock the motor to prevent it from rotating, wherein the locking finger engages the fifth clutch; the motor is a low-speed motor; the planetary confluence mechanism is used to cooperate with a plurality of mechanical and hydraulic shifting mechanisms, and by respectively engaging the first clutch, the second clutch, the third clutch and the fourth clutch, the four clutches realize four continuously variable speed sections, and at the same time, the fifth clutch and the sixth clutch are provided on the planetary confluence mechanism as two mode switching clutches, so that the entire transmission system has four working modes, providing the best fuel efficiency and the maximum torque output under various working conditions; wherein, the entire transmission system can work in the following four modes: a pure mechanical stepped speed mode, a pure electric drive continuously variable speed mode, an oil-electric series hybrid continuously variable speed mode, and an oil-electric parallel flow hybrid continuously variable speed mode; wherein, the eighth clutch is a forward clutch, and the ninth clutch is a reverse clutch.

2. A four-section and multi-working mode continuously variable transmission according to claim 1, characterized in that: A seventh clutch is mounted on the second transmission shaft.

3. A four-section and multi-working mode continuously variable transmission according to claim 1, characterized in that: The electric motor is connected to a power storage device.

4. A four-section and multi-working mode continuously variable transmission according to claim 3, characterized in that: The first transmission shaft is connected to a generator, and the generator is connected to the power storage device and the electric motor respectively.

5. A four-section and multi-working mode continuously variable transmission according to claim 1, characterized in that: The motor has forward and reverse rotation functions.

6. A tractor, characterized in that: It comprises a four-section and multi-working mode continuously variable transmission device as described in any one of claims 1 to 5.

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