Speed change device for agricultural machine and agricultural machine

Abstract

The speed change device comprises a power input shaft and two output half shafts, the power input shaft is connected with the output half shafts through two transmission lines, and two electromagnetic clutches are installed on the transmission line of each output half shaft. A driving part of each electromagnetic clutch is fixedly connected with a driving part gear meshed with the preceding stage gear, a driven part of each electromagnetic clutch and a clutch shaft of the electromagnetic clutch synchronously act, and each clutch shaft is statically connected with an output gear; by controlling the on-off state of each electromagnetic clutch, the four output gears alternately output torque to the rear-stage gear to drive the output half shaft. The agricultural machine can be flexibly and reliably controlled, the transmission energy efficiency is high, and remote control or unmanned operation is facilitated.

Description

Technical Field

[0001] The invention relates to the technical field of agricultural machinery, in particular to a speed change device for agricultural machinery. Background Art

[0002] In the process of agricultural modernization, with the rapid development of large-scale agricultural operations and precision agricultural technology, the operation mode of agricultural machinery is facing the dual challenges of rising labor costs and increasing requirements for operation precision. This has led to the transformation of agricultural machinery from traditional manual operation to less-managed or unmanned operation modes. As the core component of agricultural machinery, the remote control or unmanned operation capability of the speed change device of agricultural machinery has become an inevitable development trend. The transmission devices used in traditional agricultural machinery mainly include mechanical gearboxes, hydraulic automatic gearboxes, and electric drive gearboxes. These three types of gearboxes face the following problems in remote control and unmanned adaptation: 1. Although the mechanical gearbox has a simple and reliable structure, its reliance on manual shifting operations leads to slow response speed and low control accuracy; 2. Although the hydraulic automatic gearbox has achieved a certain degree of automated control, the control system is complex and requires the configuration of hydraulic pumps, control valve groups, actuator motors and other components; the energy needs to be converted twice from mechanical energy to hydraulic energy to mechanical energy, and the transmission efficiency is low; the hydraulic components require high processing accuracy, high manufacturing costs, and difficult later maintenance; 3. Although the electric drive gearbox has flexible control, it faces two key constraints in actual applications. First, in terms of power supply, in order to meet the power requirements of field operations, it is necessary to match large-capacity on-board batteries or generators, which not only increases the weight of the entire machine, but also leads to an increase in the manufacturing cost of the equipment; second, in terms of continuous operation capability, due to the limitations of current battery technology, the motor drive system has obvious problems of limited continuous operation capability during continuous high-intensity operations. Summary of the invention

[0003] The object of the present invention is to provide a speed changing device which can realize precise motion control of agricultural machinery, efficient power transmission and facilitate remote control or unmanned operation.

[0004] In order to solve the above problems, the technical solution adopted by the present invention is: this speed change device for agricultural machinery includes a power input shaft and two output half shafts, the power input shaft is respectively connected to the corresponding output half shafts through different transmission routes, and two electromagnetic clutches are installed on the transmission route of each output half shaft, the active part of each electromagnetic clutch is fastened with the active part gear meshing with the front-stage gear, the driven part of the electromagnetic clutch moves synchronously with the clutch shaft of the electromagnetic clutch, and each clutch shaft is statically connected with an output gear; the on and off state of each electromagnetic clutch is controlled so that the four output gears alternately output torque to the rear-stage gear, and the rear-stage gear drives the corresponding output half shaft.

[0005] In the technical solution of the above-mentioned speed change device for agricultural machinery, a more specific technical solution may further be: both ends of each of the clutch shafts are supported by the middle partition of the machine case and the transmission case body through bearings.

[0006] In some possible implementation manners, a gear shifting tooth is installed on the power input shaft. The gear shifting tooth axially slides to selectively engage with a plurality of gear teeth on the gear shaft. A transition tooth is also installed on the gear shaft. The gear teeth and the transition teeth are respectively in transmission connection with the corresponding driving part gears. The number of teeth of the transition tooth is the same as that of the gear tooth for transmitting power backward.

[0007] In some possible implementation manners, a reverse transmission mechanism for transmitting power to make the output half shafts rotate reversely is provided on the reverse transmission routes of each of the output half shafts.

[0008] In some possible implementation manners, the reverse transmission mechanism is any one of the following: The driving part gear of the electromagnetic clutch located at the previous stage on each of the transmission routes serves as the reverse transmission mechanism; A reverse gear is additionally provided between the transition tooth or the gear tooth for transmitting power backward and the driving part gear on the same side. The reverse gear and the reverse shaft serve as the reverse transmission mechanism; A multi-stage double gear is provided between the electromagnetic clutch and the output half shaft on the same side. A reverse gear is additionally provided between the driving tooth of the first-stage double gear and the output gear. The reverse gear and the reverse shaft serve as the reverse transmission mechanism.

[0009] In some possible implementation manners, the transmission mechanism from the first-stage double gear to the corresponding output half shaft is a common part of the forward transmission route and the reverse transmission route on the same side.

[0010] Another object of the present invention is to provide an agricultural machine, and the transmission used therein is the speed change device for agricultural machinery described in any one of the above.

[0011] In the technical solution of the above-mentioned agricultural machine, a more specific technical solution may further be: the output half shaft is connected to the driving wheel through a coupling, and the driving wheel is in transmission connection through a chain or a bevel gear transmission box.

[0012] In some possible implementation manners, the on-off state of the electromagnetic clutch is controlled by a control unit. The output end of the control unit is connected to the electromagnetic coil of the electromagnetic clutch. The input end of the control unit is connected to the output end of a receiver. The receiver is connected to a remote control transmitter through a wireless signal; the control unit further includes an interlock circuit, and the output end of the interlock circuit is connected to the electromagnetic coil of the electromagnetic clutch on the same side.

[0013] Due to the adoption of the above technical solution, the present invention has the following beneficial effects compared with the prior art: 1. The variable speed device for agricultural machinery of the present invention realizes precise motion control, efficient power transmission and convenient remote control or unmanned operation through the innovative combination of electromagnetic clutches and gear transmission; each output half shaft is equipped with two electromagnetic clutches, and a total of four electromagnetic clutches are provided to achieve bilateral independent control, which not only endows the agricultural machinery with super maneuverability of 360-degree rotation in place in both directions, but also enables it to maintain excellent stability and reliability in complex operating environments; by precisely controlling the on-off state of the electromagnetic clutches, the forward rotation, reverse rotation or stop of each output half shaft can be flexibly adjusted, realizing precise motion control of forward, backward and steering, fully meeting the stringent requirements of unmanned operation for motion accuracy; compared with traditional mechanical gearboxes, the control of electromagnetic clutches is more convenient and suitable for electric control or remote control operation; compared with hydraulic automatic gearboxes, the energy transmission efficiency is higher, avoiding energy loss; compared with electric drive gearboxes, its manufacturing cost and later maintenance cost are significantly reduced.

[0014] 2. Both ends of each clutch shaft are supported by the middle partition of the machine case and the gearbox housing through bearings respectively, and two coaxial clutch shafts are ensured to be independent of each other and non-interfering. This double-support structure enables the clutch shaft to obtain a uniform force distribution, improves the rigidity of the shafting, effectively suppresses vibration and yaw during high-speed operation, and realizes the dual improvement of structural stability and transmission accuracy, which is especially suitable for the stringent requirements of frequent forward and reverse rotations in unmanned operation.

[0015] 3. The design of the gear position mechanism realizes multi-gear switching to adapt to different operating requirements; the gear position switching operation is simple, improving the applicability of the agricultural machine and the user experience; the number of teeth of the transition teeth on the gear position shaft is the same as that of the gear teeth for transmitting power backward, so that the speed ratios of the left and right transmission paths are the same, ensuring that the speeds of the left and right half shafts are consistent.

[0016] 4. The reverse transmission mechanism is combined with the forward transmission path, and the forward and reverse switching can be realized by controlling the alternating engagement of the electromagnetic clutches on the same side, simplifying the operation process and improving the use convenience; multiple implementation schemes of the reverse transmission mechanism are provided, significantly improving the performance and application value of the gearbox transmission system, being able to adapt to different mechanical structure requirements and application scenarios, and meeting the requirements of agricultural machinery under different working conditions.

[0017] 5. The shared part of the transmission mechanism simplifies the overall structure, reduces the number of components required in the forward and reverse paths, reduces the complexity of design and manufacturing, saves space and manufacturing costs at the same time; in addition, the shared transmission mechanism also reduces the energy loss during power transmission, improves the transmission efficiency, and ensures more efficient power transmission in both forward and reverse directions.

[0018] 6. Provide two transmission methods of chain and bevel gear, which can be used in crowded areas to adapt to different operating environments and requirements.

[0019] 7. Set up a control unit, a remote control transmitter and a receiver, which provide a reliable technical basis for the remote control and unmanned operation of agricultural machines. At the same time, it significantly enhances the operation safety and reduces the failure risk. Through the design of the interlock circuit, it effectively avoids the simultaneous connection of electromagnetic clutches on the same side, prevents gear damage, and further improves the reliability and service life of the system. Description of the Drawings

[0020] Figure 1 It is a schematic structural diagram of Embodiment 1 of this speed change device.

[0021] Figure 2 It is a schematic structural diagram of Embodiment 2 of this speed change device.

[0022] Figure 3 It is a schematic structural diagram of Embodiment 3 of this speed change device.

[0023] Figure 4 It is a schematic diagram of the connection structure of the middle partition board of the chassis.

[0024] Figure 5 It is Figure 4 A cross-sectional view in the A-A direction.

[0025] Figure 6 It is a schematic structural diagram of Embodiment 1 of this agricultural machine.

[0026] Figure 7 It is a schematic structural diagram of Embodiment 2 of this agricultural machine.

[0027] Explanation of the reference numerals in the attached drawings: 1. First gear shift tooth; 2. Second gear shift tooth; 3. Third gear shift tooth; 4. First gear tooth; 5. Second gear tooth; 6. Third gear tooth; 7. Intermediate tooth; 8. First driving part gear; 9. Second driving part gear; 10. First output gear; 11. Second output gear; 12. Left intermediate double driving gear; 13. Left intermediate double driven gear; 14. Left reduction double driving gear; 15. Left reduction double driven gear; 16. Left half shaft gear; 17. Left half shaft; 18. Left reduction shaft; 19. Intermediate shaft; 20. Second clutch shaft; 21. Second electromagnetic clutch; 21A. Second driving part; 21B. Second driven part; 22. First clutch shaft; 23. First electromagnetic clutch; 23A. First driving part; 23B. First driven part; 24. Gear shift shaft; 25. Power input shaft; 26. Gearbox housing; 27. Pulley; 28. Third driving part gear; 29. Fourth driving part gear; 30. Third output gear; 31. Fourth output gear; 32. Right intermediate double driving gear; 33. Right intermediate double driven gear; 34. Right reduction double driving gear; 35. Right reduction double driven gear; 36. Right half shaft gear; 37. Right half shaft; 38. Right reduction shaft; 39. Fourth clutch shaft; 40. Fourth electromagnetic clutch; 40A. Fourth driving part; 40B. Fourth driven part; 41. Third clutch shaft; 42. Third electromagnetic clutch; 42A. Third driving part; 42B. Third driven part; 43. Intermediate partition in the chassis; 44. Left reverse gear; 45. Right reverse gear; 46. Reverse shaft; 47. Frame; 48. Left front driving wheel; 49. Left rear driving wheel; 50. Sprocket; 51. Chain; 52. Coupling; 53. Gearbox; 54. Gearbox output end pulley; 55. Power unit output end pulley; 56. Power unit; 57. Right front driving wheel; 58. Right rear driving wheel; 59. Rear rotary tillage box pulley; 60. Rear rotary tillage box; 61. Rear rotary tillage blade; 62. Bevel gear transmission box; 63. Connecting shaft. Detailed implementation manners

[0028] The speed change device of the present invention has the characteristics of simple structure and flexible control. It can flexibly switch multiple operation modes through the precise control of the electromagnetic clutch, and fully adapt to the power transmission and steering control requirements of agricultural machinery under different working conditions. The speed change device of the present invention mainly includes a power input shaft and two output half shafts, and the power input shaft is respectively connected to the two output half shafts through two transmission routes. The speed change device for agricultural machinery is composed of three-level functional mechanisms, the first level is a shift mechanism, that is, a variable reduction ratio transmission stage; the second level is a steering control mechanism, in which the left and right power transmission routes are respectively branched into positive and negative transmission branches; the third level is an output mechanism, that is, a fixed reduction ratio transmission stage. The steering control mechanism is provided with four electromagnetic clutches, and two electromagnetic clutches are respectively provided on the transmission route of each output half shaft. The active part of each electromagnetic clutch is fastened with an active part gear meshing with the previous stage gear, and the active part gear rotates concentrically around the clutch shaft through a bearing or a sleeve or a direct sliding fit; and the driven part of the electromagnetic clutch moves synchronously with the clutch shaft. Each clutch shaft is statically connected to an output gear, which meshes with the corresponding subsequent gear and ultimately drives the corresponding output half-shaft. By controlling the on / off state of the electromagnetic clutch on the transmission route of each output half-shaft, the four output gears can be independently controlled to start and stop. The output gears control the two output half-shafts to independently realize forward rotation, reverse rotation or stop, and ultimately control the entire machine to realize various motion states.

[0029] It is worth mentioning that the housing of the speed change device for agricultural machinery can adopt an integrated design, integrating the left and right transmission routes into one housing to simplify the structure and improve the overall rigidity; a chassis partition can also be set in the middle of the steering control mechanism area in the housing, and a clutch bearing installation position is provided on the chassis partition, so that the four clutch shafts can rotate independently without interfering with each other, see Figure 1 , Figure 4 and Figure 5 The speed change device for agricultural machinery can also be arranged in two independent housings according to actual needs, so as to facilitate maintenance and modular design.

[0030] The power input shaft is equipped with a gear shifter tooth, which slides axially to select and engage a single gear tooth on the gear shaft to achieve gear switching. The gear shaft is also equipped with a transition tooth, which is respectively connected to the corresponding driving gear to achieve power transmission. The transition tooth has the same number of teeth as the gear tooth that transmits power backwards, ensuring the consistency of the transmission speed ratio.

[0031] The electromagnetic clutch in the following embodiments is a commercially available product, which comes with its own bearings. The electromagnet part of the electromagnetic clutch is supported by bearings between the self - contained spline shaft or bushing, ensuring the motion isolation between the electromagnet part statically connected to the transmission body and the rotating driven part. The clutch shaft is a spline shaft with bearing positions at both ends, and the middle part supports the driving part gear through bearings; the driving part and the driven part of the electromagnetic clutch are not connected when not energized, and the driving part gear rotates idly around the clutch shaft (without load). Only when the electromagnetic coil of the electromagnetic clutch is energized, the driving part and the driven part will be attracted together, and the friction surface generates frictional force under the attraction pressure to transmit torque.

[0032] It is worth mentioning that a reverse transmission mechanism for transmitting power to make the output half - shaft rotate in the reverse direction is provided on the reverse transmission route of each output half - shaft. The forward transmission route and the reverse transmission route differ by an odd number of gear transmissions, ensuring that the rotation directions of the forward and reverse rotations of the output half - shaft are opposite. The reverse transmission mechanism can be any one of the following or other mechanisms with the same reverse principle: 1. The driving part gear of the electromagnetic clutch located at the previous stage on each transmission route serves as the reverse transmission mechanism. Referring to Embodiment 1 of the speed - change device for agricultural machinery, the two driving part gears on the same side are meshed with each other; 2. A reverse gear is added between the intermediate gear or the gear for transmitting power backward and the driving part gear on the same side. The reverse gear and the reverse shaft serve as the reverse transmission mechanism. Referring to Embodiment 2 of the speed - change device for agricultural machinery, the two driving part gears on the same side are not meshed with each other, and the added reverse gear is meshed between the driving part gear on the reverse route and the gear for transmitting power to the subsequent stage or the intermediate gear, playing a reverse role; 3. A multi - stage double - linked gear is provided between the electromagnetic clutch and the output half - shaft on the same side. The two driving part gears on the same side are not meshed with each other. A reverse gear is added between the driving tooth of the first - stage double - linked gear and the output gear. The reverse gear and the reverse shaft serve as the reverse transmission mechanism. Referring to Embodiment 3 of the speed - change device for agricultural machinery. The multi - stage double - linked gear includes a transition double - linked gear and a reduction double - linked gear. The transition double - linked gear is meshed with the output gear and the reduction double - linked gear respectively, the reduction double - linked gear is meshed with the half - shaft gear, and the half - shaft gear is statically connected to the output half - shaft.

[0033] The present invention will be further described in detail below with reference to the embodiments accompanied by drawings: Embodiment 1 of the speed - change device for agricultural machinery As Figure 1As shown, the two output half shafts of the speed change device of this embodiment are respectively the left half shaft 17 and the right half shaft 37, and the two output half shafts are connected to the power input shaft 25 through the transmission mechanism inside the gearbox to realize the distribution and transmission of power. The power input shaft 25 is arranged in the housing 26 of the speed change device, and one end of the power input shaft 25 is connected to the gearbox input end pulley 27 for receiving external power input. The shift mechanism of the speed change device for agricultural machinery includes a gear shift gear, a gear shaft and a gear gear, wherein the gear shift gear includes a first gear shift gear 1, a second gear shift gear 2 and a third gear shift gear 3, and the gear shaft 24 is equipped with a first gear gear 4, a second gear gear 5, a third gear gear 6 and a transition gear 7 for realizing multi-gear transmission of power. The second gear gear 5 and the transition gear 7 have the same number of teeth to ensure that the speeds of the left half shaft 17 and the right half shaft 37 remain consistent. During operation, the corresponding gear shifting tooth on the power input shaft 25 is moved by the shift fork to engage with a gear tooth on the gear shaft 24, thereby realizing the gear switching.

[0034] The steering control mechanism of the speed change device for agricultural machinery includes four electromagnetic clutches, four clutch shafts, four driving gears, four output gears, a chassis partition plate for mounting bearings, etc. The electromagnet part is statically connected to the chassis 26, and the electromagnet part is mounted on the spline sleeve of the first driven part 23B of the first electromagnetic clutch 23 through a bearing to ensure that the static electromagnet part and the rotating first driven part 23B are isolated from each other in motion; the spline sleeve of the first driven part 23B is spline-connected to the first clutch shaft 22 to achieve synchronous motion; the first driving gear 8 is tightly connected to the first driving part 23A of the first electromagnetic clutch 23, and the first driving gear 8 is mounted on the first clutch shaft 22 through a bearing to ensure that the first driving gear 8 can rotate concentrically with the first clutch shaft 22 and can be isolated in motion; the first output gear 10 is statically connected to the first clutch shaft 22; the left end of the first clutch shaft 22 is mounted on the bearing position of the chassis 26 through a bearing, and the right end is mounted on the bearing position of the chassis partition plate 43 through a bearing. When the electromagnet part is not energized, the first active part 23A and the first driven part 23B are not attracted, the first active part gear 8 rotates idly around the first clutch shaft 22, and the first clutch shaft 22 is stationary; when the electromagnet part is energized, the first active part 23A and the first driven part 23B are attracted, the first active part gear 8 transmits the torque to the first output gear 10 through the first clutch shaft 22, and the first output gear 10 transmits the torque to the left half shaft 17 through the rear gear. The installation method of the remaining second, third and fourth electromagnetic clutches is the same as that of the first electromagnetic clutch 22.

[0035] In the steering mechanism, the first driving gear 8 and the third driving gear 28 are respectively meshed with the upper gear teeth 5 and the transition teeth 7. The second driving gear 9 is meshed with the first driving gear 8, and the fourth driving gear 29 is meshed with the third driving gear 28.

[0036] The output mechanism of the speed change device for agricultural machinery in this embodiment mainly includes an intermediate shaft 19, a left reduction shaft 18, a right reduction shaft 38, a left half shaft 17, a right half shaft 37 and corresponding gears. An intermediate shaft 19 is provided with a left intermediate double gear composed of a left intermediate double driving gear 12 and a left intermediate double driven gear 13, and a right intermediate double gear composed of a right intermediate double driving gear 32 and a right intermediate double driven gear 33. The left and right intermediate double gears are respectively installed on the intermediate shaft through support bearings, and rotate independently without interference. A left reduction double gear composed of a left reduction double driving gear 14 and a left reduction double driven gear 15 is fixedly installed on the left reduction shaft 18; a right reduction double gear composed of a right reduction double driving gear 34 and a right reduction double driven gear 35 is fixedly installed on the right reduction shaft 38. A left half shaft gear 16 is fixedly connected to the left half shaft 17, and a right half shaft gear 36 is fixedly connected to the right half shaft 37.

[0037] In this embodiment, by precisely controlling the on-off states of four electromagnetic clutches (the first electromagnetic clutch 23, the second electromagnetic clutch 21, the third electromagnetic clutch 42, and the fourth electromagnetic clutch 40), multiple operation modes can be realized, including forward, reverse, steering, and 360-degree in-situ steering modes. The following combines Figure 1 to elaborate on the specific transmission routes and actions of each mode in detail, so as to better understand the flexibility and versatility of the speed change device in actual operations.

[0038] 1. Forward mode: In the forward mode, by shifting the position of the gear shifting teeth on the power input shaft 25, a certain gear tooth on the gear shifting shaft is selected to engage, and the power is transmitted to the gear shifting shaft 24. Then, the second gear 5 meshes with the first driving part gear 8, and the intermediate gear 7 meshes with the third driving part gear 28. Control the first electromagnetic clutch 23 and the third electromagnetic clutch 42 to engage. At the same time, the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 do not engage. The power is transmitted to the subsequent gears through the output gear, and the driving power is transmitted to the subsequent gears through the output gear, and finally drives the left half shaft 17 and the right half shaft 37 to rotate forward synchronously, so as to realize the smooth forward movement of the whole machine. The following is the specific transmission route and action of the positive rotation of the left and right half shafts in this embodiment.

[0039] (1) Transmission route and action of the positive rotation of the left half shaft 17: Power is transmitted from the belt pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected through the gear shifting teeth. The power is transmitted to the gear shaft 24 via the corresponding shifting teeth, and then the first driving gear 8 of the first driving part is driven to rotate through the second gear 5. The first driving gear 8 of the first driving part is fixedly connected to the first driving part 23A of the first electromagnetic clutch 23. Therefore, the first driving part 23A rotates synchronously with the first driving gear 8. When the first electromagnetic clutch 23 is energized and engaged, the first driving part 23A is combined with the first driven part 23B, and the power is transmitted to the first driven part 23B. The first driven part 23B rotates synchronously with the first clutch shaft 22. The first clutch shaft 22 drives the first output gear 10 to rotate. The first output gear 10 meshes with the left transition double-connected driving gear 12, and the power is transmitted to the left transition double-connected driven gear 13, the left reduction double-connected driving gear 14, and the left reduction double-connected driven gear 15 in sequence, and finally drives the left half shaft gear 16 to rotate, thereby driving the left half shaft 17 to rotate forward.

[0040] (2)Forward rotation transmission route and actions of the right half shaft 37: Power is transmitted from the belt pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected through the gear shifting teeth. The power is transmitted to the gear shaft 24 via the corresponding shifting teeth, and then the third driving gear 28 of the third driving part is driven to rotate through the transition gear 7. The third driving gear 28 of the third driving part is fixedly connected to the third driving part 42A of the third electromagnetic clutch 42. Therefore, the third driving part 42A rotates synchronously with the third driving gear 28. When the third electromagnetic clutch 42 is energized and engaged, the third driving part 42A is combined with the third driven part 42B, and the power is transmitted to the third driven part 42B. The third driven part 42B rotates synchronously with the third clutch shaft 41, and the third clutch shaft 41 drives the third output gear 30 to rotate. The third output gear 30 meshes with the right transition double-connected driving gear 32, and the power is transmitted to the right transition double-connected driven gear 33, the right reduction double-connected driving gear 34, and the right reduction double-connected driven gear 35 in sequence, and finally drives the right half shaft gear 36 to rotate, thereby driving the right half shaft 37 to rotate forward.

[0041] 2. Reverse mode: In this mode, control the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 to engage. At the same time, the first electromagnetic clutch 23 and the third electromagnetic clutch 42 do not engage. Both the left half shaft 17 and the right half shaft 37 rotate backward synchronously, so as to realize the reverse movement of the whole machine. The following are the specific transmission routes and actions of the left and right half shafts reversing in this embodiment.

[0042] (1)Reverse rotation transmission route and actions of the left half shaft 17: Power is transmitted from the pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected through the gear shift teeth. The power is transmitted to the gear shaft 24 via the corresponding gear shift teeth, and then drives the first driving part gear 8 to rotate through the second gear 5. The first driving part gear 8 drives the second driving part gear 9 to rotate. The second driving part gear 9 is fixedly connected to the second driving part 21A of the second electromagnetic clutch 21. Therefore, the second driving part 21A rotates synchronously with the second driving part gear 9. When the second electromagnetic clutch 21 is energized and engaged, the second driving part 21A is combined with the second driven part 21B, and the power is transmitted to the second driven part 21B. The second driven part 21B rotates synchronously with the second clutch shaft 20, and the second clutch shaft 20 drives the second output gear 11 to rotate. The second output gear 11 meshes with the left transition double-connected driving gear 12, and the power is sequentially transmitted to the left transition double-connected driven gear 13, the left reduction double-connected driving gear 14, and the left reduction double-connected driven gear 15, and finally drives the left half shaft gear 16 to rotate, thereby driving the left half shaft 17 to reverse.

[0043] (2)Reverse transmission route and action of the right half shaft 37: Power is transmitted from the pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected through the gear shift teeth. The power is transmitted to the gear shaft 24 via the corresponding gear shift teeth, and then drives the third driving part gear 28 to rotate through the transition gear 7. The third driving part gear 28 drives the fourth driving part gear 29 to rotate. The fourth driving part gear 29 is fixedly connected to the fourth driving part 40A of the fourth electromagnetic clutch 40. Therefore, the fourth driving part 40A rotates synchronously with the fourth driving part gear 29. When the fourth electromagnetic clutch 40 is energized and engaged, the fourth driving part 40A is combined with the fourth driven part 40B, and the power is transmitted to the fourth driven part 40B. The fourth driven part 40B rotates synchronously with the fourth clutch shaft 39, and the fourth clutch shaft 39 drives the fourth output gear 31 to rotate. The fourth output gear 31 meshes with the right transition double-connected driving gear 32, and the power is sequentially transmitted to the right transition double-connected driven gear 33, the right reduction double-connected driving gear 34, and the right reduction double-connected driven gear 35, and finally drives the right half shaft gear 36 to rotate, thereby driving the right half shaft 37 to reverse.

[0044] 3. Left-turn shifting steering mode: In this mode, neither the first electromagnetic clutch 23 nor the second electromagnetic clutch 21 on the left side is engaged, and the left half shaft 17 is in a free state disengaged from the power source; the third electromagnetic clutch 42 is engaged and the fourth electromagnetic clutch 40 is not engaged. Referring to the "forward rotation transmission route and actions of the right half shaft 37" mentioned above, the right half shaft 37 rotates forward. The whole machine uses the wheels on the left half shaft 17 as the fulcrum to achieve left-turn shifting movement. This left-turn shifting steering mode is suitable for scenarios of small-range precise steering. However, since the wheels on the left half shaft 17 are in a free state, in the track drive or four-wheel drive mode, due to the large contact area between the track or wheels and the ground, the wheels on the left half shaft 17 cannot provide driving force, resulting in a significant increase in steering resistance and making steering more difficult. Therefore, this mode is more suitable for use under low-resistance or soft ground conditions, especially in the drive mode where there are single wheels on both the left and right sides, which can achieve flexible small-range steering.

[0045] 4. Right-turn shifting steering mode: In this mode, neither the third electromagnetic clutch 42 nor the fourth electromagnetic clutch 40 on the right side is engaged, and the right half shaft 37 is in a free state disengaged from the power source; the first electromagnetic clutch 23 on the left side is engaged and the second electromagnetic clutch 21 is not engaged. Referring to the "forward rotation transmission route and actions of the left half shaft 17" mentioned above, the left half shaft 17 rotates forward. The whole machine uses the wheels on the right half shaft 37 as the fulcrum to achieve right-turn shifting movement. This right-turn shifting steering mode is suitable for scenarios of small-range precise steering. However, since the wheels installed on the right half shaft 37 are in a free state, in the track drive or four-wheel drive mode, due to the large contact area between the track or wheels and the ground, the wheels on the right half shaft 37 cannot provide driving force, resulting in a significant increase in steering resistance and making steering more difficult. Therefore, this mode is also more suitable for use under low-resistance or soft ground conditions, especially in the drive mode where there are single wheels on both the left and right sides, which can achieve flexible small-range steering. The shifting mode is suitable for the steering control of traditional two-wheel drive agricultural machines, such as walking tractors, and it is easy to achieve in-situ steering with a single-side wheel as the fulcrum.

[0046] 5. Leftward in-situ 360-degree steering mode: In this mode, the second electromagnetic clutch 21 on the left side and the third electromagnetic clutch 42 on the right side are engaged. For the left transmission route, refer to the "reverse transmission route and movement of the left half shaft 17" mentioned above, and the left half shaft 17 rotates in the reverse direction; for the right transmission route, refer to the "forward transmission route and movement of the right half shaft 37" mentioned above, and the right half shaft 37 rotates forward. Since the rotation directions of the left and right half shafts are opposite, the whole machine realizes a 360-degree leftward rotation in place. This steering mode can obtain a very small turning radius and low steering resistance, and is especially suitable for crawler-driven or four-wheel-driven agricultural machinery. In the crawler-driven mode, due to the opposite movements of the left and right crawlers, the steering resistance is effectively dispersed, thus achieving an excellent steering effect. This mode is very suitable for use in narrow spaces or operation scenarios that require high-precision steering. Due to the support of crawlers or four wheels, the whole machine has good stability and is not easy to roll over, making it suitable for the upgrade of agricultural machinery to remote control or unmanned operation.

[0047] 6. Rightward in-situ 360-degree steering mode: In this mode, the first electromagnetic clutch 23 on the left side and the fourth electromagnetic clutch 40 on the right side are engaged. For the left transmission route, refer to the "forward transmission route and movement of the left half shaft 17" mentioned above, and the left half shaft 17 rotates forward; for the right transmission route, refer to the "reverse transmission route and movement of the right half shaft 37" mentioned above, and the right half shaft 37 rotates in the reverse direction. Since the rotation directions of the left and right half shafts are opposite, the whole machine realizes a 360-degree rightward rotation in place. This steering can obtain a very small turning radius and low steering resistance, and is especially suitable for crawler-driven or four-wheel-driven agricultural machinery. In the crawler-driven mode, due to the opposite movements of the left and right crawlers, the steering resistance is effectively dispersed, thus achieving an excellent steering effect. This mode is very suitable for use in narrow spaces or operation scenarios that require high-precision steering. Due to the support of crawlers or four wheels, the whole machine has good stability and is not easy to roll over, making it suitable for the upgrade of agricultural machinery to remote control or unmanned operation.

[0048] Embodiment 2 of the speed change device for agricultural machinery The speed change device for agricultural machinery in this embodiment provides a reverse transmission structure different from that in Case 1. In this structure, the first driving part gear 8 and the second driving part gear 9 are not engaged, and the third driving part gear 28 and the fourth driving gear 29 are not engaged, so that the four driving part gears are respectively stressed during forward and reverse rotations, realizing balanced stress. Specifically, as Figure 2 shown, a reverse shaft 46 is added in the gearbox. A left reverse gear 44 and a right reverse gear 45 are installed on the reverse shaft 46. The left reverse gear 44 and the right reverse gear 45 can rotate independently around the reverse shaft 46, and they are supported by bearings or sliding sleeves or directly in sliding fit with the reverse shaft 46. The left reverse gear 44 is simultaneously engaged with the second gear 5 and the second driving part gear 9, and the right reverse gear 45 is simultaneously engaged with the intermediate gear 7 and the fourth driving part gear 29. Other structures of this embodiment are the same as those of Embodiment 1 of the speed change device for agricultural machinery.

[0049] Combine the following Figure 2 The specific transmission routes and actions of this embodiment including forward, backward, turning and 360-degree turning modes on the spot are described in detail.

[0050] 1. Forward mode: In the forward mode, the first electromagnetic clutch 23 and the third electromagnetic clutch 42 are engaged, while the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 are not engaged, and the left half shaft 17 and the right half shaft 37 both rotate forward, thereby realizing the whole machine moving forward. The forward mode transmission route of this embodiment is the same as that of embodiment 1.

[0051] 2. Reverse mode: In this mode, the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 are engaged, while the first electromagnetic clutch 23 and the third electromagnetic clutch 42 are not engaged, and the left half shaft 17 and the right half shaft 37 both rotate backward synchronously, thereby realizing the reverse movement of the whole machine. The following is the specific transmission route and action of the left and right half shafts reversing in this embodiment.

[0052] (1) Reverse transmission route and action of left half shaft 17: The power is transmitted from the pulley 27 at the input end of the gearbox to the power input shaft 25, and then the gear is selected by shifting the gear shift gear. The power is transmitted to the gear shaft 24 via the corresponding shift gear, and then drives the left reverse gear 44 to rotate through the second gear gear 5. The left reverse gear 44 drives the second active part gear 9 to rotate. The second active part gear 9 is tightly connected to the second active part 21A of the second electromagnetic clutch 21, so the second active part 21A rotates synchronously with the second active part gear 9. When the second electromagnetic clutch 21 is energized and attracted, the second active part 21A is combined with the second driven part 21B, and the power is transmitted to the second driven part 21B. The second driven part 21B rotates synchronously with the second clutch shaft 20, and the second clutch shaft 20 drives the second output gear 11 to rotate. The second output gear 11 meshes with the left transition double driving gear 12, and the power is transmitted to the left driven gear 13 of the left transition double gear, the left reduction double driving gear 14 and the left reduction double driven gear 15 in sequence, and finally drives the left half shaft gear 16 to rotate, thereby driving the left half shaft 17 to reverse.

[0053] (2) Reverse transmission route and action of right half shaft 37: The power is transmitted from the pulley 27 at the input end of the gearbox to the power input shaft 25, and then the gear is selected by shifting the gear shift gear, and the power is transmitted to the gear shaft 24 via the corresponding gear shift gear, and then drives the right reverse gear 45 to rotate through the transition gear 7. The right reverse gear 45 drives the fourth active part gear 29 to rotate. The fourth active part gear 29 is tightly connected to the fourth active part 40A of the fourth electromagnetic clutch 40, so the fourth active part 40A rotates synchronously with the fourth active part gear 29. When the fourth electromagnetic clutch 40 is powered on and attracted, the fourth active part 40A is combined with the fourth driven part 40B, and the power is transmitted to the fourth driven part 40B. The fourth driven part 40B rotates synchronously with the fourth clutch shaft 39, and the fourth clutch shaft 39 drives the fourth output gear 31 to rotate. The fourth output gear 31 meshes with the right transition double driving gear 32, and the power is transmitted to the right transition double driven gear 33, the right reduction double driving gear 34 and the right reduction double driven gear 35 in sequence, and finally drives the right half shaft gear 36 to rotate, thereby driving the right half shaft 37 to reverse.

[0054] 3. The left turn and shifting mode, the right turn and shifting mode, the left turn 360 degree steering mode, and the right turn 360 degree steering mode are consistent with the agricultural machinery transmission device embodiment 1, and are realized by controlling the four electromagnets to cooperate or independently engage. The specific transmission route can refer to the agricultural machinery transmission device embodiment 1.

[0055] Agricultural machinery speed change device embodiment 3 The agricultural machinery transmission device of this embodiment provides a reverse transmission structure different from the agricultural machinery transmission device embodiment 1. Under this structure, the first driving gear 8 and the second driving gear 9 are not meshed, and the third driving gear 28 and the fourth driving gear 29 are not meshed, so that the four driving gears are subjected to force respectively during forward and reverse rotation, achieving balanced force. Figure 3 As shown, compared with the agricultural machinery transmission embodiment 1, this embodiment also adds a reversing shaft 46, a left reversing gear 44 and a reversing gear 45. The reversing principle is similar to that of the agricultural machinery transmission embodiment 2. The difference from the agricultural machinery transmission embodiment 2 is that the added left reversing gear 44 is arranged between the output gear 10 of the left reversing transmission route and the left transition double driving tooth 12, instead of arranging the left reversing gear 44 between the second gear 5 and the second driving part gear 9 as in embodiment 2; similarly, the added right reversing gear 45 of this embodiment is also arranged between the output gear 30 of the right reversing transmission route and the right transition double driving tooth 32, instead of arranging the right reversing gear 45 between the transition tooth 7 and the fourth driving part gear 29 as in embodiment 2.

[0056] Specifically, the present embodiment also adds a reversing shaft 46 in the gearbox, on which a left reversing gear 44 and a right reversing gear 45 are mounted; the left reversing gear 44 and the right reversing gear 45 rotate independently around the reversing shaft 46 and do not interfere with each other, and they are supported by bearings or sliding sleeves with the reversing shaft 46 or directly slide in cooperation with the reversing shaft 46.

[0057] Combine the following Figure 3 The specific transmission routes and actions of this embodiment including forward, backward, turning and 360-degree turning modes on the spot are described in detail.

[0058] 1. Forward mode: In the forward mode, the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 are engaged, while the first electromagnetic clutch 23 and the third electromagnetic clutch 42 are not engaged, and the power is transmitted to the subsequent gear through the output gear, and finally the left half shaft 17 and the right half shaft 37 are driven to rotate forward synchronously, so that the whole machine can move forward smoothly. The following is the specific transmission route and action of the forward rotation of the left and right half shafts in this embodiment.

[0059] (1) Forward transmission route and action of left half shaft 17: The power is transmitted from the pulley 27 at the input end of the gearbox to the power input shaft 25, and then the gear is selected by shifting the gear shift gear, and the power is transmitted to the gear shaft 24 through the corresponding shift gear, and then the second driving part gear 9 is driven to rotate through the second gear gear 5. The second driving part gear 9 is tightly connected to the second driving part 21A of the second electromagnetic clutch 21, so the second driving part 21A rotates synchronously with the second driving part gear 9. When the second electromagnetic clutch 21 is energized and attracted, the second driving part 21A is combined with the second driven part 21B, and the power is transmitted to the second driven part 21B. The second driven part 21B rotates synchronously with the second clutch shaft 20, and the second clutch shaft 20 drives the second output gear 11 to rotate. The second output gear 11 is meshed with the left transition double driving gear 12, and the power is transmitted to the left transition double driven gear 13, the left reduction double driving gear 14, and the left reduction double driven gear 15 in sequence, and finally drives the left half shaft gear 16 to rotate, thereby driving the left half shaft 17 to rotate forward.

[0060] (2) Right half shaft 37 forward rotation transmission route and action: Power is transmitted from the belt pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected by toggling the gear shift teeth. The power is transmitted to the gear shaft 24 via the corresponding shift teeth, and then drives the fourth driving gear 29 of the active part to rotate through the intermediate gear 7. The fourth driving gear 29 of the active part is fixedly connected to the fourth driving part 40A of the fourth electromagnetic clutch 40. Therefore, the fourth driving part 40A rotates synchronously with the fourth driving gear 29 of the active part. When the fourth electromagnetic clutch 40 is energized and engaged, the fourth driving part 40A is combined with the fourth driven part 40B, and the power is transmitted to the fourth driven part 40B. The fourth driven part 40B rotates synchronously with the fourth clutch shaft 39, and the fourth clutch shaft 39 drives the fourth output gear 31 to rotate. The fourth output gear 31 meshes with the right intermediate double driving gear 32, and the power is transmitted to the right intermediate double driven gear 33, the right reduction double driving gear 34, and the right reduction double driven gear 35 in sequence, and finally drives the right half shaft gear 36 to rotate, thereby driving the right half shaft 37 to rotate forward.

[0061] 2. Reverse mode: In this mode, control the first electromagnetic clutch 23 and the third electromagnetic clutch 42 to engage. At the same time, the second electromagnetic clutch 21 and the fourth electromagnetic clutch 40 are not engaged. The left half shaft 17 and the right half shaft 37 both rotate backward synchronously, so as to realize the reverse of the whole machine. The following is the specific transmission route and action of the left and right half shafts reversing in this embodiment.

[0062] (1) Transmission route and action of the left half shaft 17 reversing: Power is transmitted from the belt pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected by toggling the gear shift teeth. The power is transmitted to the gear shaft 24 via the corresponding shift teeth, and then drives the first driving gear 8 of the active part to rotate through the second gear 5. The first driving gear 8 of the active part is fixedly connected to the first driving part 23A of the first electromagnetic clutch 23. Therefore, the first driving part 23A rotates synchronously with the first driving gear 8 of the active part. When the first electromagnetic clutch 23 is energized and engaged, the first driving part 23A is combined with the first driven part 23B, and the power is transmitted to the first driven part 23B. The first driven part 23B rotates synchronously with the first clutch shaft 22, and the first clutch shaft 22 drives the first output gear 10 to rotate. The first output gear 10 meshes with the left reverse gear 44, and the power is transmitted to the left intermediate double driving gear 12, the left intermediate double driven gear 13, the left reduction double driving gear 14, and the left reduction double driven gear 15 in sequence, and finally drives the left half shaft gear 16 to rotate, thereby driving the left half shaft 17 to reverse.

[0063] (2) Transmission route and action of the right half shaft 37 reversing: Power is transmitted from the belt pulley 27 at the input end of the gearbox to the power input shaft 25. Subsequently, the gear is selected by shifting the gear shift teeth. The power is transmitted to the gear shaft 24 via the corresponding shift teeth, and then drives the third driving gear 28 of the third driving part to rotate through the intermediate gear 7. The third driving gear 28 of the third driving part is fixedly connected to the third driving part 42A of the third electromagnetic clutch 42. Therefore, the third driving part 42A rotates synchronously with the third driving gear 28. When the third electromagnetic clutch 42 is energized and engaged, the third driving part 42A is combined with the third driven part 42B, and the power is transmitted to the third driven part 42B. The third driven part 42B rotates synchronously with the third clutch shaft 41, and the third clutch shaft 41 drives the third output gear 30 to rotate. The third output gear 30 meshes with the right reverse gear 45, and the power is transmitted to the right intermediate double driving gear 32, the right intermediate double driven gear 33, the right right reduction double driving gear 34, and the right reduction double driven gear 35 in sequence, and finally drives the right half axle gear 36 to rotate, thereby driving the right half axle 37 to reverse.

[0064] 3. Left turn and move steering mode: In this mode, neither the first electromagnetic clutch 23 nor the second electromagnetic clutch 21 on the left side is engaged, and the left half axle 17 is in a free state with the meshing teeth disengaged; the third electromagnetic clutch 42 on the right side is not engaged, and the fourth electromagnetic clutch 40 is engaged. Referring to the "forward rotation transmission route and action of the right half axle 37" described above in this embodiment, the right half axle 37 rotates forward. The whole machine uses the wheels on the left half axle 17 as the fulcrum to achieve left turn and move movement.

[0065] 4. Right turn and move steering mode: In this mode, neither the third electromagnetic clutch 42 nor the fourth electromagnetic clutch 40 on the right side is engaged, and the right half axle 37 is in a free state with the meshing teeth disengaged; the first electromagnetic clutch 23 on the left side is not engaged, and the second electromagnetic clutch 21 is engaged. Referring to the "forward rotation transmission route of the left half axle 17" described above in this embodiment, the left half axle 17 rotates forward. The whole machine uses the wheels on the right half axle 37 as the fulcrum to achieve right turn and move movement.

[0066] 5. Left 360-degree in-place steering mode: In this mode, the first electromagnetic clutch 23 on the left side and the fourth electromagnetic clutch 40 on the right side are engaged. The left transmission route refers to the "reverse rotation transmission route and action of the left half axle 17" described above in this embodiment, and the left half axle 17 rotates backward; the right transmission route refers to the "forward rotation transmission route and action of the right half axle 37" described above in this embodiment, and the right half axle 37 rotates forward. Since the rotation directions of the left and right half axles are opposite, the whole machine realizes a 360-degree left in-place rotation.

[0067] 6. Rightward in-place 360-degree turning mode: In this mode, the second electromagnetic clutch 21 on the left side and the third electromagnetic clutch 42 on the right side are engaged. For the left transmission route, refer to the "forward rotation transmission route and actions of the left half shaft 17" described above in this embodiment, and the left half shaft 17 rotates forward; for the right transmission route, refer to the "reverse rotation transmission route and actions of the right half shaft 37" described above, and the right half shaft 37 rotates backward. Since the rotation directions of the left and right half shafts are opposite, the whole machine realizes a 360-degree rightward rotation in place.

[0068] Agricultural machine Embodiment 1 Figure 6 For the agricultural machine shown, its gearbox 53 adopts any one of the above-mentioned speed-changing devices for agricultural machinery, and combines power transmission and control systems to achieve efficient power transmission and flexible operation control, meeting the diverse needs of modern agricultural machinery. The agricultural machine of this embodiment mainly includes a frame 47, a power machine 56, a gearbox 53, drive wheels, transmission components, a rear rotary tillage device, and a control system. The power machine 56 transmits power to the gearbox 53 through the power machine output pulley 55, a V-belt, and the gearbox input pulley 30. The left and right half shafts of the gearbox 53 output torque to the left front drive wheel 48 and the right front drive wheel 57 through couplings 52 respectively. To ensure the continuity and stability of power transmission, sprockets 50 and chains 51 equipped on the axles of the left front drive wheel 48 and the left rear drive wheel 49 are used for transmission, and the right front drive wheel 57 and the right rear drive wheel 58 are also driven by sprockets 50 and chains 51 in the same way.

[0069] In addition, the agricultural machine is also equipped with a rear rotary tillage device to meet tillage requirements. On the basis of the above-mentioned power transmission, the gearbox output pulley 54 connected to the gearbox 53 transmits power to the rear rotary tillage box 60 through a V-belt and the rear rotary tillage box pulley 59. A rear rotary tillage blade 61 or a rotary tillage wheel is installed on the output shaft of the rear rotary tillage box 60 for high-speed rotation to loosen the soil. This not only improves tillage efficiency but also enhances the versatility of the whole machine.

[0070] To achieve flexible operation control, the left half shaft 42 and the right half shaft 43 of the transmission 53 are controlled by electromagnetic clutches, enabling combined or individual movement. By controlling the on-off state of the electromagnetic clutches, the whole machine can perform operations such as forward rotation, reverse, left and right turns, in-situ rotation, and rotation of the rear rotary tillage cutter. The control of the electromagnetic clutches is achieved by a control unit. The output end of the control unit is connected to the electromagnetic coil of the electromagnetic clutch, and the input end is connected to the output end of the receiver. The receiver communicates with the remote control transmitter through wireless signals, thus realizing remote control of the whole machine. In addition, the control unit is also equipped with an interlock circuit. Its input end is connected to the signal processing module of the control unit, and the output end is connected to the electromagnetic coil of the electromagnetic clutch on the same side, for precisely controlling the on-off state of the electromagnetic clutch on the same side to ensure the stability and safety of the operation. The control unit can adopt controller devices such as PLC (Programmable Logic Controller) or single-chip microcomputer to meet the requirements of different application scenarios.

[0071] Agricultural machine Embodiment 2 As Figure 7 shown, the front and rear two drive wheels on the same side of the agricultural machine in this embodiment are driven through two bevel gear transmission boxes 62 and a connecting shaft 63, avoiding the chain from being rusted by mud and water. The remaining features are the same as those of the agricultural machine Embodiment 1.

[0072] The present invention adopts multiple electromagnetic clutches in cooperation with the design of the clutch shaft and the gear transmission route, featuring flexible steering and precise control of the motion state, and is particularly suitable for four-wheel drive agricultural machinery. In paddy field operations, this transmission can effectively avoid mechanical sinking, requires a small turning radius, and can achieve a 360-degree in-situ turn, significantly improving the operation efficiency. For paddy fields in the hilly areas of the south, especially those with irregular or small field plots, the advantages of the present invention are particularly prominent. Its flexible control performance and adaptability can meet the operation requirements of complex terrains, greatly improving the practicality and operation effect of agricultural machinery.

Claims

1. A speed change device for agricultural machinery, comprising a power input shaft and two output half shafts, wherein the power input shaft is respectively connected to the corresponding output half shafts through different transmission routes, characterized in that: Two electromagnetic clutches are installed on the transmission route of each output half-shaft, the active part of each electromagnetic clutch is tightly connected to the active part gear meshing with the preceding gear, the driven part of the electromagnetic clutch moves synchronously with the clutch shaft of the electromagnetic clutch, and each clutch shaft is statically connected with an output gear; the on and off state of each electromagnetic clutch is controlled so that the four output gears alternately output torque to the succeeding gear, and the succeeding gear drives the corresponding output half-shaft.

2. The speed change device for agricultural machinery according to claim 1, characterized in that: Both ends of each clutch shaft are supported by a chassis partition and a gearbox housing through bearings.

3. The speed change device for agricultural machinery according to claim 2, characterized in that: The power input shaft is equipped with a gear shift tooth, and the gear shift tooth slides axially to select and engage multiple gear teeth on the gear shaft. The gear shaft is also equipped with a transition tooth, and the gear tooth and the transition tooth are respectively connected to the corresponding driving part gear transmission, and the transition tooth has the same number of teeth as the gear tooth that transmits power backward.

4. The speed change device for agricultural machinery according to claim 3, characterized in that: A reverse transmission mechanism for transmitting power to cause the output half shaft to rotate in the reverse direction is arranged on the reverse transmission route of each output half shaft.

5. The speed change device for agricultural machinery according to claim 4, characterized in that: The reverse transmission mechanism is any one of the following: The driving gear of the electromagnetic clutch located at the front stage on each transmission route serves as the reverse transmission mechanism; A reverse gear is added between the transition tooth or the gear tooth transmitting power backward and the driving part gear on the same side, and the reverse gear and the reverse shaft serve as the reverse transmission mechanism; A multi-stage double-toothed gear is arranged between the electromagnetic clutch and the output half shaft on the same side, and a reversing gear is added between the driving gear of the first stage of the double-toothed gear and the output gear. The reversing gear and the reversing shaft serve as the reversing transmission mechanism.

6. The speed change device for agricultural machinery according to claim 5, characterized in that: The transmission mechanism from the first-stage double-tooth to the corresponding output half-shaft is a common part of the forward transmission route and the reverse transmission route on the same side.

7. An agricultural machine, comprising a gearbox, characterized in that: The gearbox is a speed change device for agricultural machinery according to any one of claims 1 to 6.

8. The agricultural machine according to claim 7, characterized in that: The output half shaft is connected to the driving wheel through a coupling, and the driving wheel is connected through a chain or a bevel gear transmission box.

9. The agricultural machine according to claim 8, characterized in that: The on and off state of the electromagnetic clutch is controlled by a control unit, the output end of the control unit is connected to the electromagnetic coil of the electromagnetic clutch, the input end of the control unit is connected to the output end of the receiver, and the receiver is connected to the remote control transmitter via a wireless signal; the control unit also includes an interlocking circuit, the input end of the interlocking circuit is connected to the signal processing module of the control unit, and the output end of the interlocking circuit is connected to the electromagnetic coil of the electromagnetic clutch on the same side.

Images