A large power electric tractor stepless gearbox and using method

Abstract

The application relates to the technical field of gearboxes, in particular to a stepless gearbox for a high-horsepower electric tractor and a use method, which comprises a gearbox shell, a driving shaft is rotationally connected in the interior of the gearbox shell, a motor is fixedly installed on the gearbox shell, the output shaft of the motor is fixedly connected to one end of the driving shaft, a first gear is fixedly connected to the surface of the driving shaft, an inner gear ring is rotationally connected in the interior of the gearbox shell, a transmission shaft is rotationally connected to the shaft center of the inner gear ring, a second gear is fixedly connected to one end of the transmission shaft, and the second gear and the first gear are mutually meshed; the stepless gearbox is realized by single power transmission, in a high-load working scene, power output is converted into maximum torque, and the intervention of a speed change mechanism in power output is removed, so that the pressure wear of the speed change mechanism is effectively reduced, and the service life of equipment is prolonged.

Description

Technical Field

[0001] This invention relates to the field of gearbox technology, and in particular to a continuously variable transmission (CVT) for a high-horsepower electric tractor and its usage method. Background Technology

[0002] The transmission is the core component of a car's drivetrain. Its core function is to regulate the engine's output speed and torque to adapt to the vehicle's different driving conditions. By changing the gear ratio, it balances power and economy, enabling key operations such as starting, acceleration, cruising, and reversing. It is mainly divided into manual, automatic, dual-clutch, and continuously variable transmissions (CVTs), and its performance directly affects the driving experience, fuel consumption, and smoothness. Technology is developing towards greater efficiency, intelligence, and integration with electric drive systems.

[0003] Patent document CN115435051A discloses a transmission system for a tractor and a tractor. The transmission system includes: a main gearbox; a continuously variable transmission (CVT) device disposed on one side of the main gearbox and including a power transmission shaft, wherein the power transmission shaft is provided with a travel speed drive wheel and a speed-following PTO drive wheel assembly synchronously driven by the CVT device; and a travel speed control wheel system disposed in the main gearbox and driven by the travel speed drive wheel, wherein the transmission end of the travel speed control wheel system is simultaneously connected to the front drive system and the rear drive system of the tractor.

[0004] In existing technologies, tractors typically use CVT-type continuously variable transmissions to switch driving modes. CVTs achieve continuous gear changes through belts or steel chains and variable-diameter conical pulleys, resulting in smooth gear shifts and facilitating normal tractor operation. However, due to the harsh operating environment of tractors, when encountering slippage, getting stuck in pits in farmland or mud, or when carrying rotary tillers for high-load work, the pressure on the belts or steel chains increases dramatically, which can easily cause excessive stretching, wear, or even breakage of the belts or steel chains, limiting their support for high-horsepower and high-load scenarios. Summary of the Invention

[0005] The purpose of this invention is to address the shortcomings of existing technologies by proposing a continuously variable transmission (CVT) for high-horsepower electric tractors and its usage method.

[0006] To achieve the above objectives, the technical solution adopted by the present invention is as follows: a continuously variable transmission (CVT) for a high-horsepower electric tractor, comprising a transmission housing, a drive shaft rotatably connected inside the transmission housing, a motor fixedly mounted on the transmission housing, an output shaft of the motor fixedly connected to one end of the drive shaft, a first gear fixedly connected to the surface of the drive shaft, an internal gear ring rotatably connected inside the transmission housing, a transmission shaft rotatably connected to the axis of the internal gear ring, a second gear fixedly connected to one end of the transmission shaft, the second gear meshing with the first gear, a sun gear fixedly connected to the other end of the transmission shaft, a planet carrier rotatably connected inside the internal gear ring, a plurality of planet gears rotatably connected to the surface of the planet carrier along the circumferential direction, the plurality of planet gears rotatably meshing between the sun gear and the internal gear ring, and a conveyor shaft fixedly connected to the axis of the planet carrier;

[0007] The gearbox housing is internally connected to a linkage shaft, and a continuously variable transmission (CVT) assembly is installed between the linkage shaft and the drive shaft. A third gear is fixedly connected to the surface of the internal gear ring, and a fourth gear is installed on the linkage shaft. The fourth gear meshes with the third gear. A transmission assembly is installed on the linkage shaft to drive the fourth gear to rotate synchronously. A locking assembly is installed on the gearbox housing to act on the fourth gear. When the locking assembly locks the fourth gear, the linkage shaft and the fourth gear are disengaged.

[0008] Preferably, the transmission assembly includes a first mounting bracket, which is fixedly connected to the inside of the gearbox housing, a fourth gear is rotatably connected to the first mounting bracket, and an electromagnetic clutch is fixedly installed between the fourth gear and the linkage shaft.

[0009] Preferably, the locking assembly includes a second mounting bracket, which is fixedly connected to the inside of the gearbox housing. A fixing ring is fixedly connected to the second mounting bracket. A first pressing ring is rotatably connected to one side of the fixing ring. A second pressing ring is provided on the side of the first pressing ring away from the fixing ring. An inclined guide surface for contact and contact is provided on the adjacent sides of the first and second pressing rings. A limit ring is rotatably connected to the second pressing ring. An elastic limit component is provided between the fixing ring and the limit ring. A locking bracket is slidably inserted into the gearbox housing. Limit pieces are fixedly connected to both the first and second pressing rings. Each limit piece has a guide groove. Two circular pins are fixedly connected to the locking bracket. The two circular pins are located inside the two guide grooves respectively. A contact ring is fixedly connected to the second pressing ring. The contact ring is located on one side of the fourth gear. A contact disconnect component is provided on the contact ring.

[0010] Preferably, the guide groove contacts both sides of the circular pin, and the top and bottom surfaces inside the guide groove have gaps with the circular pin.

[0011] Preferably, the contact power-off assembly includes a sliding groove, which is formed on the contact ring. A sliding plate is slidably connected inside the sliding groove. A pressure sensor is fixedly installed on the side of the sliding plate near the fourth gear. A first spring is fixedly connected between the sliding plate and one side of the sliding groove.

[0012] Preferably, a friction brake pad is fixedly connected to the side of the contact ring adjacent to the fourth gear, and the pressure sensor passes through the corresponding friction brake pad and extends to the outside.

[0013] Preferably, the elastic limiting component includes a first arc-shaped strip and a second arc-shaped strip. The first arc-shaped strip is fixedly connected to the fixed ring, and the second arc-shaped strip is fixedly connected to the limiting ring. Multiple limiting pins are fixedly connected to the second arc-shaped strip. The multiple limiting pins are slidably inserted into the first arc-shaped strip, and a second spring is sleeved on each of the multiple limiting pins. The second spring is fixedly connected between the first arc-shaped strip and one end of the corresponding limiting pin.

[0014] Preferably, the continuously variable transmission (CVT) assembly includes a driving cone pulley and a driven cone pulley, both of which are fixedly mounted on the gearbox housing. The driving cone pulley and the driven cone pulley are respectively fixedly connected to the drive shaft and the linkage shaft. A steel belt connects the driving cone pulley and the driven cone pulley for power transmission. A driving gearbox is fixedly mounted on the driving cone pulley, and a matching gearbox is fixedly mounted on the driven cone pulley.

[0015] Preferably, the two sides inside the driving and driven cone pulleys are V-shaped, and the steel belt slides and fits in contact with the inside of the driving and driven cone pulleys.

[0016] A method for using a continuously variable transmission (CVT) for a high-horsepower electric tractor, the method comprising the following steps:

[0017] Step 1: The motor's conveyor shaft drives the drive shaft to rotate, and the drive shaft drives the first gear to rotate synchronously. Through the meshing of the first gear and the second gear, the second gear drives the transmission shaft to rotate in coordination, and the transmission shaft drives the sun gear to rotate synchronously.

[0018] Step 2: While the drive shaft is rotating, it drives the linkage shaft to rotate at different speeds through the continuously variable transmission component. The linkage shaft drives the fourth gear to rotate synchronously through the transmission component. Through the meshing of the fourth gear and the third gear, the internal gear ring rotates. Through the different speed difference between the internal gear ring and the sun gear, multiple planet gears mesh with the internal gear ring and the sun gear, driving the planet carrier to output different speeds, which are then transmitted to the conveyor shaft to achieve continuously variable transmission.

[0019] Step 3: When the tractor encounters slippage, getting stuck in a pit, or is working under high load with a rotary tiller, the locking assembly locks the fourth gear. Through the meshing of the fourth gear and the third gear, both the third gear and the internal gear ring are locked. Thus, when the motor is working, the drive shaft drives the sun gear to rotate, while the internal gear ring is locked. Multiple planetary gears, through meshing with the internal gear ring and the sun gear, drive the planetary carrier to output maximum torque.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] 1. This invention achieves continuously variable transmission of the gearbox through a single power transmission, and under high-load working conditions, it converts the power output into maximum torque and removes the intervention of the transmission mechanism in the power output, thereby effectively reducing the pressure wear of the transmission mechanism and extending the service life of the equipment.

[0022] 2. When the first and second pressing rings rotate in opposite directions, the distance between the first and second pressing rings increases due to the guiding effect of the inclined guide surface. The second pressing ring drives the contact ring to move axially towards the fourth gear, so that the contact ring contacts one side of the fourth gear. The fourth gear is locked by the contact friction force. When the contact ring contacts the fourth gear, the contact de-energizing component de-energizes the electromagnetic clutch.

[0023] 3. The pressure sensor makes room by contacting and squeezing, and drives the sliding plate to slide inside the sliding groove. At the same time, it squeezes the first spring to generate compression deformation. When the contact ring contacts the fourth gear and locks the first spring, the pressure sensor generates a pressure value through the elastic action of the first spring. When the pressure is detected, the controller connected to the pressure sensor controls the electromagnetic clutch to de-energize, thereby disengaging the transmission between the fourth gear and the linkage shaft. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is a partial structural schematic diagram of the present invention (the gearbox housing is hidden).

[0026] Figure 3 This is a schematic diagram of the mating structure of the internal gear ring, drive shaft and conveyor shaft of the present invention (the internal gear ring and the third gear are cut out).

[0027] Figure 4 This is a schematic diagram of the first mating structure of the linkage shaft and the fourth gear of the present invention;

[0028] Figure 5 For the present invention Figure 4 Enlarged schematic diagram of the structure at point A in the diagram;

[0029] Figure 6 This is a schematic diagram of the second mating structure of the linkage shaft and the fourth gear of the present invention;

[0030] Figure 7 For the present invention Figure 6 Enlarged schematic diagram of the structure at point B in the diagram;

[0031] Figure 8 This is a schematic diagram of the contact ring and friction brake pad mating structure of the present invention;

[0032] Figure 9 For the present invention Figure 8 Enlarged schematic diagram of the structure at point C;

[0033] Figure 10 This is an exploded view of the mating structure of the first and second pressing ring pieces of the present invention;

[0034] Figure 11 This is a schematic diagram of the locking bracket and circular pin mating structure of the present invention.

[0035] In the diagram: 1. Gearbox housing; 2. Drive shaft; 3. Motor; 4. First gear; 5. Internal gear ring; 6. Transmission shaft; 7. Second gear; 8. Sun gear; 9. Planet carrier; 10. Planet gears; 11. Conveyor shaft; 12. Linkage shaft; 13. Third gear; 14. Fourth gear; 15. First mounting bracket; 16. Electromagnetic clutch; 17. Second mounting bracket; 18. Retaining ring; 19. First pressure ring plate; 20. Second pressure ring plate; 21. 1. Limiting ring; 22. Locking bracket; 23. Limiting piece; 24. Guide groove; 25. Circular pin; 26. Contact ring; 27. Sliding groove; 28. Sliding piece; 29. ​​Pressure sensor; 30. First spring; 31. Friction brake pad; 32. First arc-shaped strip; 33. Second arc-shaped strip; 34. Limiting pin; 35. Second spring; 36. Driving cone wheel; 37. Driven cone wheel; 38. Steel belt; 39. Driving gearbox; 40. Matching gearbox. Detailed Implementation

[0036] The following description is intended to disclose the invention and enable those skilled in the art to implement it. The preferred embodiments described below are merely examples, and other obvious variations will occur to those skilled in the art.

[0037] like Figures 1 to 11The continuously variable transmission (CVT) for a high-horsepower electric tractor shown includes a transmission housing 1. A drive shaft 2 is rotatably connected inside the transmission housing 1. A motor 3 is fixedly mounted on the transmission housing 1. The output shaft of the motor 3 is fixedly connected to one end of the drive shaft 2. A first gear 4 is fixedly connected to the surface of the drive shaft 2. An internal gear ring 5 is rotatably connected inside the transmission housing 1. A transmission shaft 6 is rotatably connected to the axis of the internal gear ring 5. A second gear 7 is fixedly connected to one end of the transmission shaft 6, and the second gear 7 meshes with the first gear 4. A sun gear 8 (e.g., a sun gear) is fixedly connected to the other end of the transmission shaft 6. Figure 3 As shown), the planet carrier 9 is rotatably connected inside the internal gear ring 5. Multiple planet gears 10 are rotatably connected to the surface of the planet carrier 9 in the circumferential direction. The multiple planet gears 10 are all rotatably meshed between the sun gear 8 and the internal gear ring 5. A conveyor shaft 11 is fixedly connected to the axis of the planet carrier 9.

[0038] The gearbox housing 1 is rotatably connected to a linkage shaft 12. A continuously variable transmission assembly is provided between the linkage shaft 12 and the drive shaft 2. A third gear 13 is fixedly connected to the surface of the internal gear ring 5. A fourth gear 14 is provided on the linkage shaft 12. The fourth gear 14 and the third gear 13 mesh with each other. A transmission assembly is provided on the linkage shaft 12 to drive the fourth gear 14 to rotate synchronously. A locking assembly is provided on the gearbox housing 1 to act on the fourth gear 14. When the locking assembly locks the fourth gear 14, the linkage shaft 12 and the fourth gear 14 are disengaged.

[0039] When the tractor is in normal driving condition, the output shaft of the motor 3 drives the drive shaft 2 to rotate. The drive shaft 2 drives the first gear 4 to rotate synchronously. Through the meshing of the first gear 4 and the second gear 7, the second gear 7 drives the transmission shaft 6 to rotate. The transmission shaft 6 drives the sun gear 8 to rotate synchronously. While the drive shaft 2 is rotating, the continuously variable transmission assembly drives the linkage shaft 12 to rotate at different speeds. The linkage shaft 12 drives the fourth gear 14 to rotate synchronously through the transmission assembly. Through the meshing of the fourth gear 14 and the third gear 13, the internal gear ring 5 is driven to rotate. Through the different speed difference between the internal gear ring 5 and the sun gear 8, multiple planet gears 10 drive the planet carrier 9 to output different speeds through the meshing of the internal gear ring 5 and the sun gear 8, and transmit them to the conveyor shaft 11 to achieve continuously variable transmission.

[0040] When the tractor encounters slippage, getting stuck in a pit, or is carrying a rotary tiller for high-load work, the locking assembly locks the fourth gear 14. When the fourth gear 14 is locked and its rotation is restricted, the linkage shaft 12 is disengaged from the fourth gear 14. At this time, the linkage shaft 12 still rotates normally. Through the meshing of the fourth gear 14 and the third gear 13, the third gear 13 and the internal gear ring 5 are both locked. Thus, when the motor 3 is working, the transmission shaft 6 drives the sun gear 8 to rotate, while the internal gear ring 5 is locked. Multiple planetary gears 10, through meshing with the internal gear ring 5 and the sun gear 8, drive the planet carrier 9 to output maximum torque.

[0041] This invention achieves continuously variable transmission (CVT) of the gearbox through a single power transmission, and under high-load working conditions, it converts power output into maximum torque and removes the intervention of the transmission mechanism in the power output, thereby effectively reducing the pressure wear of the transmission mechanism and extending the service life of the equipment.

[0042] As a further embodiment of the present invention, the transmission assembly includes a first mounting bracket 15, which is fixedly connected to the inside of the gearbox housing 1, and a fourth gear 14 is rotatably connected to the first mounting bracket 15. An electromagnetic clutch 16 is fixedly installed between the fourth gear 14 and the linkage shaft 12.

[0043] When the linkage shaft 12 rotates, the electromagnetic clutch 16 is energized, causing multiple friction plates to transmit torque and drive the fourth gear 14 to rotate along the rotational connection of the first mounting bracket 15. When the electromagnetic clutch 16 is de-energized, the linkage shaft 12 continues to rotate while the fourth gear 14 loses its transmission power and stops rotating.

[0044] As a further embodiment of the present invention, the locking assembly includes a second mounting bracket 17, which is fixedly connected to the inside of the gearbox housing 1. A retaining ring 18 is fixedly connected to the second mounting bracket 17. A first pressing ring 19 is rotatably connected to one side of the retaining ring 18. A second pressing ring 20 is provided on the side of the first pressing ring 19 away from the retaining ring 18. Both the first pressing ring 19 and the second pressing ring 20 have inclined guide surfaces for contact and contact on adjacent sides (e.g., Figure 10 As shown), a limiting ring 21 is rotatably connected to the second pressing ring 20. An elastic limiting component is provided between the fixed ring 18 and the limiting ring 21. A locking bracket 22 is slidably inserted into the gearbox housing 1. A limiting piece 23 is fixedly connected to both the first pressing ring 19 and the second pressing ring 20. A guide groove 24 is provided on each of the limiting pieces 23. Two circular pins 25 are fixedly connected to the locking bracket 22. The two circular pins 25 are located inside the two guide grooves 24 respectively. A contact ring 26 is fixedly connected to the second pressing ring 20. The contact ring 26 is located on one side of the fourth gear 14. A contact power-off component is provided on the contact ring 26.

[0045] The elastic limiting component creates an elastic preload between the fixed ring 18 and the limiting ring 21, bringing them closer together. This also causes the first pressing ring 19 and the second pressing ring 20 to come into elastic contact. When the locking bracket 22 moves outward along the sliding joint of the gearbox housing 1, it drives the two circular pins 25 to move synchronously. Through the insertion and limiting of the circular pins 25 and the guide groove 24, the first pressing ring 19 and the second pressing ring 20 rotate in opposite directions along the rotational connection between the fixed ring 18 and the limiting ring 21. When the first pressing ring 19 and the second pressing ring 20 rotate in opposite directions, the guide effect of the inclined guide surface increases the distance between the first pressing ring 19 and the second pressing ring 20. The second pressing ring 20 drives the contact ring 26 to move axially toward the fourth gear 14, so that the contact ring 26 contacts one side of the fourth gear 14. The contact friction locks the fourth gear 14. When the contact ring 26 contacts the fourth gear 14, the contact de-energizing component de-energizes the electromagnetic clutch 16.

[0046] As a further embodiment of the present invention, the guide groove 24 contacts both sides of the circular pin 25, and the top and bottom surfaces inside the guide groove 24 have gaps with the circular pin 25.

[0047] When the locking bracket 22 moves the circular pin 25, the circular pin 25 guides the first pressing ring 19 and the second pressing ring 20 by contacting and squeezing with the inside of the guide groove 24. The gap between the circular pin 25 and the guide groove 24 at the top and bottom provides a certain clearance space for the circular pin 25 inside the guide groove 24 when the first pressing ring 19 and the second pressing ring 20 move.

[0048] As a further embodiment of the present invention, the contact power-off assembly includes a sliding groove 27, which is formed on the contact ring 26 (e.g., ...). Figure 9 As shown), a sliding plate 28 is slidably connected inside the sliding groove 27. A pressure sensor 29 is fixedly installed on the side of the sliding plate 28 near the fourth gear 14. A first spring 30 is fixedly connected between the sliding plate 28 and one side of the sliding groove 27.

[0049] The pressure sensor 29 is positioned in a protruding position on one side of the contact ring 26 by the elastic extension of the first spring 30. When the contact ring 26 approaches and contacts the fourth gear 14, the pressure sensor 29 makes way by contact compression, and drives the sliding plate 28 to slide inside the sliding groove 27. At the same time, the first spring 30 is compressed and deformed. When the contact ring 26 contacts the fourth gear 14 and locks the first spring 30, the pressure sensor 29 generates a pressure value through the elastic action of the first spring 30. When pressure is detected, the controller connected to the pressure sensor 29 controls the electromagnetic clutch 16 to de-energize, thereby disengaging the transmission between the fourth gear 14 and the linkage shaft 12.

[0050] As a further embodiment of the present invention, friction brake pads 31 are fixedly connected to the side of the contact ring 26 adjacent to the fourth gear 14, and the pressure sensor 29 passes through the corresponding friction brake pads 31 and extends to the outside.

[0051] When the contact ring 26 moves closer to the fourth gear 14, a friction brake pad 31 is installed on the side of the contact ring 26 adjacent to the fourth gear 14 to replace the contact between the contact ring 26 and the fourth gear 14. The replacement cost is reduced by replacing the friction brake pad 31. As the two friction brake pads 31 wear down, the clearance distance of the pressure sensor 29 gradually decreases each time the contact ring 26 moves a fixed distance towards the fourth gear 14, which reduces the elastic compression of the first spring 30 and causes the pressure detection value of the pressure sensor 29 to gradually decrease. The pressure detection value of the pressure sensor 29 is used to determine whether the friction brake pad 31 needs to be replaced.

[0052] As a further embodiment of the present invention, the elastic limiting component includes a first arc-shaped strip 32 and a second arc-shaped strip 33. The first arc-shaped strip 32 is fixedly connected to the fixing ring 18, and the second arc-shaped strip 33 is fixedly connected to the limiting ring 21. A plurality of limiting pins 34 are fixedly connected to the second arc-shaped strip 33. The plurality of limiting pins 34 are slidably inserted into the first arc-shaped strip 32. A second spring 35 is sleeved on the plurality of limiting pins 34. The second spring 35 is fixedly connected between the first arc-shaped strip 32 and one end of the corresponding limiting pin 34.

[0053] The relative rotation between the fixed ring 18 and the limiting ring 21 is restricted by the sliding insertion of the first arc-shaped strip 32 and multiple limiting pins 34. The limiting ring 21 has an elastic tendency towards the fixed ring 18 due to the elastic extension of the second spring 35, which drives the first pressing ring 19 and the second pressing ring 20 to elastically fit together. When the second pressing ring 20 moves away from the first pressing ring 19, the limiting ring 21 moves synchronously with the second pressing ring 20, which drives the first arc-shaped strip 32 and multiple limiting pins 34 to move. During the movement, the limiting pins 34 compress the corresponding second spring 35 to produce compression deformation.

[0054] As a further embodiment of the present invention, the continuously variable transmission assembly includes a driving cone pulley 36 and a driven cone pulley 37, both of which are fixedly mounted on the gearbox housing 1 (e.g., Figure 1 and Figure 2 As shown), the driving cone wheel 36 and the driven cone wheel 37 are fixedly connected to the drive shaft 2 and the linkage shaft 12 respectively. A steel belt 38 is connected between the driving cone wheel 36 and the driven cone wheel 37. A driving gearbox 39 is fixedly installed on the driving cone wheel 36, and a matching gearbox 40 is fixedly installed on the driven cone wheel 37.

[0055] The rotation of the drive shaft 2 drives the drive cone wheel 36 to rotate, and the steel belt 38 transmits power to the drive cone wheel 36 and the driven cone wheel 37, causing the driven cone wheel 37 to rotate in coordination. When the drive gearbox 39 increases the distance between the two sides of the drive cone wheel 36, the steel belt 38 moves closer to the axis of the drive cone wheel 36. At the same time, the gearbox 40 decreases the distance between the two sides of the driven cone wheel 37, causing the steel belt 38 to move away from the axis of the driven cone wheel 37. Through the operation of the drive gearbox 39 and the gearbox 40, the distance between the two sides of the drive cone wheel 36 and the driven cone wheel 37 is adjusted synchronously and always in opposite directions, so as to achieve continuous speed change while keeping the tension of the steel belt 38 constant.

[0056] As a further embodiment of the present invention, the two sides inside the active cone wheel 36 and the driven cone wheel 37 are V-shaped, and the steel belt 38 slides and fits in contact with the interior of the active cone wheel 36 and the driven cone wheel 37;

[0057] When the driving cone wheel 36 and the driven cone wheel 37 adjust the distance between the two sides, they make inclined contact with the steel belt 38 through the internal V-shaped surface, so that the steel belt 38 can better fit the driving cone wheel 36 and the driven cone wheel 37, and transmit power through the static friction generated on both sides of the steel belt 38.

[0058] A method for using a continuously variable transmission (CVT) for a high-horsepower electric tractor, the method comprising the following steps:

[0059] Step 1: The conveyor shaft 11 of motor 3 drives the drive shaft 2 to rotate, and the drive shaft 2 drives the first gear 4 to rotate synchronously. Through the meshing of the first gear 4 and the second gear 7, the second gear 7 drives the transmission shaft 6 to rotate in coordination, and the transmission shaft 6 drives the sun gear 8 to rotate synchronously.

[0060] Step 2: While the drive shaft 2 is rotating, it drives the linkage shaft 12 to rotate at different speeds through the action of the continuously variable transmission component. The linkage shaft 12 drives the fourth gear 14 to rotate synchronously through the action of the transmission component. Through the meshing of the fourth gear 14 and the third gear 13, the internal gear ring 5 is driven to rotate. Through the different speed difference between the internal gear ring 5 and the sun gear 8, multiple planet gears 10 drive the planet carrier 9 to output different speeds through the meshing of the internal gear ring 5 and the sun gear 8, and transmit them to the conveyor shaft 11 to achieve continuously variable transmission.

[0061] Step 3: When the tractor encounters slippage, getting stuck in a pit, or is carrying a rotary tiller under high load, the locking assembly locks the fourth gear 14. Through the meshing of the fourth gear 14 with the third gear 13, both the third gear 13 and the internal gear ring 5 are locked. Thus, when the motor 3 is working, the drive shaft 6 drives the sun gear 8 to rotate, while the internal gear ring 5 is locked. Multiple planetary gears 10, through meshing with the internal gear ring 5 and the sun gear 8, drive the planet carrier 9 to output maximum torque.

[0062] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claims. The scope of protection claimed by the appended claims and their equivalents is defined.

Claims

1. A continuously variable transmission (CVT) for a high-horsepower electric tractor, comprising a transmission housing, characterized in that, A drive shaft is rotatably connected inside the gearbox housing. A motor is fixedly mounted on the gearbox housing. The output shaft of the motor is fixedly connected to one end of the drive shaft. A first gear is fixedly connected to the surface of the drive shaft. An internal gear ring is rotatably connected inside the gearbox housing. A transmission shaft is rotatably connected to the center of the internal gear ring. A second gear is fixedly connected to one end of the transmission shaft. The second gear meshes with the first gear. A sun gear is fixedly connected to the other end of the transmission shaft. A planet carrier is rotatably connected inside the internal gear ring. Multiple planet gears are rotatably connected to the surface of the planet carrier in a circumferential direction. The multiple planet gears are all rotatably meshed between the sun gear and the internal gear ring. A conveyor shaft is fixedly connected to the center of the planet carrier. The gearbox housing is internally connected to a linkage shaft, and a continuously variable transmission assembly is provided between the linkage shaft and the drive shaft. A third gear is fixedly connected to the surface of the internal gear ring, and a fourth gear is provided on the linkage shaft. The fourth gear meshes with the third gear. A transmission assembly is provided on the linkage shaft to drive the fourth gear to rotate synchronously. A locking assembly is provided on the gearbox housing to act on the fourth gear. When the locking assembly locks the fourth gear, the linkage shaft and the fourth gear are disengaged. The transmission assembly includes a first mounting bracket, which is fixedly connected to the inside of the gearbox housing. A fourth gear is rotatably connected to the first mounting bracket, and an electromagnetic clutch is fixedly installed between the fourth gear and the linkage shaft. The locking assembly includes a second mounting bracket, which is fixedly connected to the inside of the gearbox housing. A fixing ring is fixedly connected to the second mounting bracket. A first pressing ring is rotatably connected to one side of the fixing ring. A second pressing ring is provided on the side of the first pressing ring away from the fixing ring. Both the first and second pressing rings have inclined guide surfaces for contact and contact. A limit ring is rotatably connected to the second pressing ring. An elastic limit component is provided between the fixing ring and the limit ring. A locking bracket is slidably inserted into the gearbox housing. Limit pieces are fixedly connected to both the first and second pressing rings. Each limit piece has a guide groove. Two circular pins are fixedly connected to the locking bracket. The two circular pins are located inside the two guide grooves respectively. A contact ring is fixedly connected to the second pressing ring. The contact ring is located on one side of the fourth gear. A contact disconnect component is provided on the contact ring.

2. The continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 1, characterized in that, The guide groove contacts both sides of the circular pin, and the top and bottom surfaces inside the guide groove have gaps with the circular pin.

3. The continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 1, characterized in that, The contact power-off assembly includes a sliding groove, which is formed on the contact ring. A sliding plate is slidably connected inside the sliding groove. A pressure sensor is fixedly installed on the side of the sliding plate near the fourth gear. A first spring is fixedly connected between the sliding plate and one side of the sliding groove.

4. A continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 3, characterized in that, Friction brake pads are fixedly connected to the side of the contact ring adjacent to the fourth gear, and pressure sensors pass through the corresponding friction brake pads and extend to the outside.

5. A continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 1, characterized in that, The elastic limiting component includes a first arc-shaped strip and a second arc-shaped strip. The first arc-shaped strip is fixedly connected to a fixed ring, and the second arc-shaped strip is fixedly connected to a limiting ring. Multiple limiting pins are fixedly connected to the second arc-shaped strip. The multiple limiting pins are slidably inserted into the first arc-shaped strip, and a second spring is sleeved on each of the multiple limiting pins. The second spring is fixedly connected between the first arc-shaped strip and one end of the corresponding limiting pin.

6. A continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 1, characterized in that, The continuously variable transmission (CVT) assembly includes a driving cone pulley and a driven cone pulley, both of which are fixedly mounted on the gearbox housing. The driving cone pulley and the driven cone pulley are respectively fixedly connected to the drive shaft and the linkage shaft. A steel belt connects the driving cone pulley and the driven cone pulley for power transmission. A driving gearbox is fixedly mounted on the driving cone pulley, and a matching gearbox is fixedly mounted on the driven cone pulley.

7. A continuously variable transmission (CVT) for a high-horsepower electric tractor according to claim 6, characterized in that, The inside sides of the driving and driven cone pulleys are V-shaped, and the steel belt slides and fits in contact with the inside of the driving and driven cone pulleys.

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