Agricultural machinery power reversing transmission mechanism capable of automatically switching power take-off

Abstract

The invention discloses an agricultural machinery power reversing transmission mechanism capable of automatically switching power take-off, and belongs to the technical field of transmissions. An output shaft; a power take-off shaft; the power reversing mechanism is used for switching the power direction of the output shaft; the electric control power take-off mechanism is used for controlling power transmission of the power take-off shaft; and the hydraulic control system is used for driving the power reversing mechanism and the electric control power take-off mechanism. In the reversing process, automatic forward and backward switching and automatic power output and cut-off can be achieved, the working efficiency is improved, and meanwhile the labor intensity is reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of transmissions, and in particular relates to a power reversing transmission mechanism for agricultural machinery with automatic power take-off switching. Background Art

[0002] At present, tractors or similar agricultural power machinery generally use a dry main clutch with a mechanical separation structure. When changing gears, changing driving direction, or switching the power take-off mechanism, it is necessary to step on the clutch pedal to cut off the power transmitted by the engine, and then use the mechanical gear lever to select the desired gear or realize the engagement and disengagement of the power take-off mechanism. When switching the driving direction, not only do you need to step on the clutch pedal, you also need to stop the car before switching forward / reverse. When switching directions, the power take-off mechanism needs to disengage the power output, which also requires stepping on the clutch pedal to achieve. The entire operation process is cumbersome and laborious. Especially when working on smaller plots of land, it is necessary to change the driving direction frequently, which places high demands on the driver's work intensity. At the same time, since the driving direction needs to be stopped before the operation can be performed, the working efficiency is greatly reduced.

[0003] In response to the above situation, in recent years, the domestic agricultural machinery industry has been vigorously promoting the development of power reversing technology. The invention with application number CN202322913002.7 discloses a tractor power reversing assembly, and the invention with application number CN202322015249.7 discloses a tractor power reversing transmission device, which realizes the power reversing function through different combinations of two sets of clutches. However, since the power take-off mechanism switches frequently during use, and the agricultural machinery chassis has extremely high requirements for the structural layout of the transmission system, a highly integrated product is needed to simultaneously meet the functional requirements of power reversing and automatic switching of power take-off, and at the same time, the high integration meets the layout requirements to promote the progress of agricultural machinery modernization technology.

[0004] US Patent Application No. US18608684 discloses a transmission system for a hybrid drive unit, comprising a centrifugal clutch connected to a driven shaft and connectable to an electric motor, and a clutch slider element connected to the rotor of the electric motor and slidable relative to the centrifugal clutch between three engagement positions. The transmission system also includes a clutch override assembly for rotatably connecting the centrifugal clutch and the clutch slider element to provide continuous torque transmission to the driven shaft when switching between a pure electric drive mode and at least one hybrid drive mode. This invention enables rapid power transmission, but in the prior art, agricultural machinery requires frequent power reversing during operation, which is a cumbersome operation. This US Patent does not address this issue. Summary of the Invention

[0005] The object of the present invention is to provide a highly integrated agricultural machinery power reversing transmission mechanism with high transmission efficiency and simple reversing operation.

[0006] The technical solutions adopted by the present invention to achieve the above-mentioned purpose are: A power reversing transmission mechanism for agricultural machinery with automatic power take-off switching comprises: an input shaft; an output shaft; a power take-off shaft; a power reversing mechanism for switching the power direction of the output shaft; an electronically controlled power take-off mechanism for controlling power transmission to the power take-off shaft; and a hydraulic control system for driving the power reversing mechanism and the electronically controlled power take-off mechanism. Engine power is transmitted to the power reversing mechanism via the input shaft. When the driving direction needs to be changed, the hydraulic system drives the forward or reverse clutch to engage, allowing the output shaft to obtain forward or reverse rotational power. Simultaneously, the electronically controlled power take-off mechanism controls the power on and off of the power take-off shaft according to operational requirements. The hydraulic oil pump draws power through the intermediate shaft and supplies oil to each actuator. The hydraulic system synchronously controls the operation of multiple clutches, achieving integrated operation of driving direction switching and power take-off control, eliminating the operational steps of parking reversing and manually pressing the clutch. During continuous operation, the driver can synchronously switch driving direction and power take-off status through electronic control commands, reducing power interruption time and significantly improving operational efficiency.

[0007] Preferably, the input shaft, output shaft, and power take-off shaft are coaxially arranged, and the power take-off shaft is centrally disposed within the output shaft. The power take-off shaft passes through the output shaft and is rotationally connected to the input shaft at one end. The power take-off shaft is coaxially mounted with the input shaft via a seventh bearing, and the power take-off shaft is coaxially mounted with the output shaft via a bearing. Compared to the prior art, the coaxial arrangement of the power take-off shaft and the output shaft of the present invention reduces the axial layout space of the transmission shaft assembly, making the structure of the entire transmission system compact, reducing the manufacturing cost of the system, and effectively reducing the axial length and radial volume of the transmission system, allowing the clutch mechanism to be centrally disposed at the shaft end connection. For example, in a tractor chassis layout, this design can avoid spatial interference between the power take-off shaft and the output shaft, reducing the complexity of the housing structure, while also reducing the number of bearing support points, facilitating maintenance operations.

[0008] Preferably, the system further includes an intermediate shaft, which is engaged with the input shaft via gears. The power take-off shaft is rotationally connected to the input shaft and the output shaft via bearings. The input shaft, intermediate shaft, output shaft, and power take-off shaft are each mounted on the housing via bearings and can rotate independently. The coaxial rotational connection of the input shaft, output shaft, and power take-off shaft reduces lateral interference between the shafts during power transmission, reduces shaft wear, and improves the stability of the transmission system. While the shafts are assembled and connected to the housing via bearings, the shafts are connected to each other via bearings, ensuring the coaxiality of the multiple shafts, thereby helping to improve mechanical transmission efficiency. This application not only realizes power diversion by introducing an intermediate shaft and gear meshing transmission, but also drives the hydraulic oil pump through the intermediate shaft, reducing the need for arranging additional power sources, and solving the problems of low transmission efficiency and hydraulic system dependence on external power caused by the lack of an intermediate shaft in traditional power reversing mechanisms. Power diversion is achieved through gear meshing and coordination with the intermediate shaft, reducing the load on the transmission chain, while providing integrated power input for the hydraulic control system, thereby improving the compactness and reliability of the transmission system.

[0009] Preferably, the hydraulic control system includes a hydraulic oil pump, and the intermediate shaft drives the hydraulic oil pump through a chain transmission mechanism.

[0010] Preferably, the chain transmission mechanism includes: a first sprocket fixed to the driving end of the hydraulic oil pump; a second sprocket fixed to the intermediate shaft; and a second chain connecting the first sprocket and the second sprocket. The above connection method realizes the operation of driving the hydraulic oil pump through the intermediate shaft. Preferably, the power reversing mechanism includes a forward gear clutch and a reverse gear clutch, which are respectively used to realize the same-direction power transmission and reverse power transmission between the output shaft and the input shaft.

[0011] Preferably, the power reversing mechanism transmits power between the intermediate shaft and the output shaft via a chain drive system. The chain drive system achieves forward and reverse switching through a single transmission path, which not only simplifies the shaft system layout but also reduces maintenance costs through the detachable nature of the chain. This solves the problem of complex transmission system structure and difficult maintenance when agricultural machinery frequently changes direction. The chain drive system achieves efficient power transmission in a compact layout, while ensuring a fast switching response. It also improves the reliability of the transmission system in adverse working conditions such as muddy and bumpy conditions and reduces the failure rate caused by wear of transmission components.

[0012] Preferably, the chain transmission system includes: a second sprocket, coaxially mounted on the intermediate shaft via a bearing and capable of axially rotating relative to the intermediate shaft; a fourth sprocket, fixed to the output shaft; and a second chain, connecting the third sprocket and the fourth sprocket. The connection between the non-coaxial intermediate shaft and the output shaft is achieved through the third sprocket and the second chain, and the clutch system can realize power transmission, which helps to reduce the pressure acting on the intermediate shaft and the output shaft, stabilize the transmission efficiency of the intermediate shaft and the output shaft, and through the coordinated control of the chain transmission system and the clutch, the reversing operation can be completed without interrupting the power transmission. At the same time, the non-rigid contact characteristics of the chain transmission reduce the mechanical impact during the reversing process, realize the flexible switching of the transmission path during the power reversing process, solve the reliability problems caused by the parking operation and gear impact required for traditional mechanical reversing, and simplify the axial space occupied by the transmission system to meet the requirements of the agricultural machinery chassis for a compact layout.

[0013] Preferably, the forward gear clutch includes: a fourth outer hub, connected to the output shaft; a third inner hub, connected to the input shaft and located on the inner side of the fourth outer hub; a forward friction plate group, integrated between the inner side of the fourth outer hub and the outer side of the third inner hub; a second piston, used to control the engagement and disengagement of the forward friction plate group, when the forward friction plate group is engaged, the output shaft and the input shaft are fixed and rotate synchronously; a second return spring group, used to push the second piston back to separate the forward friction plate group to cut off the power of the output shaft.

[0014] Preferably, the forward friction plate group includes: a fourth active friction plate group, connected to the third inner hub; a third driven friction plate group, connected to the fourth outer hub; the second piston is installed in the inner cavity of the fourth outer hub, and one side of the second return spring group is in contact with the second piston, and the other side is fixed to the fourth outer hub. Through the control of the solenoid valve, the oil pressure established by the oil pump is introduced into the cavity of the second piston and the fourth outer hub. The second piston will push the third driven friction plate group and the fourth active friction plate group to combine, so that the output shaft and the input shaft are fixed and run together, and finally achieve forward output in the same direction; after the pressure oil in the second piston is cut off by the solenoid valve, the second return spring group will push the second piston back, so that the third driven friction plate group and the fourth active friction plate group are separated, thereby cutting off the power of the output shaft; the coaxial rotation connection between the input shaft and the output shaft helps to improve the contact stability when the third driven friction plate group and the fourth active friction plate group are combined, that is, the third driven friction plate group can maintain the same posture and close contact with the fourth active friction plate group, on the one hand, improving the power transmission efficiency from the input shaft to the output shaft, on the other hand, reducing the severe local wear of the friction plate due to the tilted posture, reducing the possibility of friction plate damage caused by gear shifting during driving, improving driving safety and reducing maintenance costs.

[0015] Preferably, the reverse clutch includes: a sixth outer hub, connected to the intermediate shaft; a fifth inner hub, connected to the third sprocket and located on the inner side of the sixth outer hub; a reverse friction plate group, integrated between the inner side of the sixth outer hub and the outer side of the fifth inner hub; a third piston, used to control the engagement and disengagement of the reverse friction plate group, when the reverse friction plate group is engaged, the intermediate shaft and the sprocket are fixed and rotate synchronously; a third return spring group, used to push the third piston back to disengage the reverse friction plate group to cut off the power of the output shaft.

[0016] Preferably, the reverse gear friction plate group includes: a fifth active friction plate group connected to the sixth outer hub; a sixth driven friction plate group connected to the fifth inner hub; a third piston mounted in the inner cavity of the sixth outer hub; a third return spring group in contact with the third piston on one side and fixed to the sixth outer hub on the other side. Through solenoid valve control, the oil pressure generated by the oil pump is introduced into the cavity of the third piston and the sixth outer hub, and the third piston pushes the fifth active friction plate group and the sixth driven friction plate group to engage, achieving the fixation and synchronous operation of the intermediate shaft and the third sprocket, thereby achieving reverse power output between the output shaft and the input shaft, and ultimately achieving reverse gear output; after the pressure oil in the third piston is cut off by the solenoid valve, the third return spring group pushes the third piston back to its original position, causing the fifth active friction plate group and the sixth driven friction plate group to separate, thereby cutting off power to the output shaft.

[0017] Preferably, the electronically controlled power take-off mechanism includes a power take-off clutch, which is used to realize power transmission between the input shaft and the power take-off shaft.

[0018] Preferably, the power take-off clutch includes: a first outer hub, connected to the input shaft; a second inner hub, connected to the power take-off shaft and located on the inner side of the first outer hub; a power take-off friction plate group, integrated between the inner side of the first outer hub and the outer side of the second inner hub; a first piston, used to control the engagement and disengagement of the power take-off friction plate group, when the power take-off friction plate group is engaged, the power of the input shaft is transmitted to the power take-off shaft in the same direction; a first return spring group, used to push the first piston back to disengage the power take-off friction plate group to cut off the power of the power take-off shaft.

[0019] Preferably, the power take-off friction plate group includes: a first active friction plate group, connected to the first outer hub; a second driven friction plate group, connected to the second inner hub; a first piston is installed in the inner cavity of the first outer hub, one side of the first return spring group is in contact with the first piston, and the other side is fixed to the first outer hub. Through solenoid valve control, the oil pressure generated by the oil pump is introduced into the cavity of the first piston and the first outer hub. The first piston pushes the first active friction plate group and the second driven friction plate group to engage. At this time, the power of the input shaft passes through the first outer hub, the first active friction plate group, the second driven friction plate group, and the second inner hub, and finally realizes power transmission to the power take-off shaft. After the pressure oil in the first piston is cut off through solenoid valve control, the first return spring group pushes the first piston back to its original position, causing the first active friction plate group and the second driven friction plate group to separate, thereby cutting off the power to the power take-off shaft. The through-hole arrangement of the power take-off shaft and the output shaft ensures that the various components of the power take-off clutch system can be relatively concentratedly arranged at the connection between the input shaft and the power take-off shaft, which optimizes the spatial layout of the power take-off clutch system and reduces the axial layout length. On the one hand, this reduces the manufacturing cost of the power take-off clutch system, and on the other hand, it helps to shorten the extension and retraction stroke of the first piston and improve the response speed of power transmission and cut-off. Since the power take-off shaft passes through the output shaft and is connected to the input shaft through a bearing, the first outer hub and the second inner hub surround the outer periphery of the bearing at the connection point, which can realize the transition connection between the input shaft and the power take-off shaft, further ensure the coaxiality of the shaft rotation, and reduce the power loss caused by shaking during the rotation of the shaft.

[0020] Preferably, the second inner hub surrounds the connecting bearing between the input shaft and the PTO shaft, allowing all lubricating oil passing through the connecting bearing to be applied to the PTO friction plate pack. This second inner hub can reduce lubricating oil loss in the bearing at the connection between the input shaft and the PTO shaft, reducing the frequency of lubricating oil addition and lowering maintenance costs. It also increases the lubricating oil flow rate to the friction plate pack, enhancing heat dissipation efficiency and reducing the risk of wear or ablation of the friction plates due to high temperatures, thereby ensuring smooth power transmission from the PTO shaft. The second inner hub forms a lubricating oil diversion channel by surrounding the bearing, directing all lubricating oil from the bearing to the PTO friction plate pack. This ensures that the lubricating oil lubricates both the bearing and the friction plates, eliminating the need for independent lubricating oil circuits and reducing the complexity and cost of the lubrication system. The structure of the second inner hub surrounding the bearing can form an annular uniform flow guide, allowing the bearing lubricating oil to flow evenly into the power take-off friction plate group from all sides, making the lubricating oil more evenly distributed on the surface of the power take-off friction plate, reducing local wear and extending the service life of the power take-off friction plate.

[0021] Preferably, the coaxial, through-and-through arrangement of the PTO shaft and the output shaft allows the clutch mechanism to be centrally located at the shaft connection. This through-and-through arrangement allows the PTO clutch system and the reversing clutch system to be centrally located within the space between the input shaft, the output shaft, and the PTO shaft's rotational connection. The oil pressure generated by the oil pump quickly switches between the third and second pistons, accelerating the shifting speed between forward and reverse gears and improving vehicle operation and driving efficiency.

[0022] Preferably, the hydraulic control system controls the engagement and disengagement of the clutch via a solenoid valve.

[0023] Preferably, the power reversing mechanism realizes power transmission between the intermediate shaft and the output shaft through a gear transmission system.

[0024] Preferably, the gear transmission system includes: a first gear mounted on the output shaft; a second gear mounted on the intermediate shaft through a seventh bearing; and an idler gear for transmission connection between the first gear and the first gear to achieve co-directional rotation of the output shaft and the intermediate shaft.

[0025] The above-mentioned clutch reversing system only needs to input instructions to the oil pump to realize the function of automatically switching the driving direction of the vehicle while driving, as well as the automatic engagement and separation of the power take-off mechanism. That is, the power reversing and electronically controlled automatic power take-off of the transmission system can be realized through simple instructions. It not only realizes automatic control to improve work efficiency and reduce labor intensity, but also makes the structural scheme of the entire transmission system compact and reduces system costs through optimized structural design.

[0026] Since the present invention realizes automatic control of the power of the power take-off shaft by controlling the power take-off clutch, it has the following technical effects: the input shaft, the output shaft and the power take-off shaft are coaxially arranged and can respectively realize independent rotation through bearings, and cooperate with the chain drive system and the clutch to realize power transmission, thereby improving the power transmission efficiency; the power take-off shaft is arranged through the output shaft, which reduces the axial layout length of the transmission shaft group and reduces the manufacturing cost; the through-center arrangement of the power take-off shaft and the output shaft reduces the stroke amplitude of the piston and improves the response speed; the second inner hub is surrounded on the outside of the connection between the input shaft and the power take-off shaft, which can reduce the leakage of lubricating oil and ensure the power transmission stability of the power take-off shaft; the clutch reversing system only needs to input instructions to the oil pump to realize power reversing and electronically controlled automatic power take-off, thereby improving working efficiency and reducing labor intensity. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is a schematic diagram of the overall structure of a power reversing transmission mechanism for agricultural machinery with automatic power take-off switching; Figure 2 for Figure 1 A magnified schematic diagram of area A in the middle; Figure 3 for Figure 1 A magnified schematic diagram of area B in the middle; Figure 4 Schematic diagram of the structure of the fourth sprocket W4; Figure 5 is a partial cross-sectional schematic diagram of the fourth sprocket W4; Figure 6 It is a cross-sectional schematic diagram of the fourth W4 sprocket and auxiliary parts.

[0028] Reference numerals: housing 1; input shaft S1; intermediate shaft S2; output shaft S3; power take-off shaft S4; oil pump OP; first bearing B1; second bearing B2; third bearing B3; fourth bearing B4; fifth bearing B5; sixth bearing B6; seventh bearing B7; first sprocket W1; first chain CH1; second sprocket W2; second chain CH2; third sprocket W3; fourth sprocket W4, first outer hub H1; second inner hub H2; first return spring group SP1; first active friction plate group CL1; second driven friction plate group CL2; first Piston P1; fourth outer hub H4; third inner hub H3; second return spring group SP2; fourth active friction plate group CL4; third driven friction plate group CL3; second piston P2; sixth outer hub H6; fifth inner hub H5; third return spring group SP3; fifth active friction plate group CL5; sixth driven friction plate group CL6; third piston P3; wheel body 20; shaft hole 21; mounting hole 22; first circular arc wall 221; second circular arc wall 222; auxiliary element 3; outer shell 30; hollow groove 31; cylindrical pin 32; limit portion 33. DETAILED DESCRIPTION

[0029] The technical solution of the present invention is further described in detail below with reference to the specific embodiments and the accompanying drawings: Obviously, the embodiments described are only some of the embodiments of the present invention, not all of them. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0030] Example 1: A power reversing transmission mechanism for agricultural machinery with automatic power take-off switching comprises: a housing 1; an input shaft S1; an output shaft S3; a power take-off shaft S4; a power reversing mechanism for switching the power direction of the output shaft S3; an electronically controlled power take-off mechanism for controlling the power transmission of the power take-off shaft S4; and a hydraulic control system for driving the power reversing mechanism and the electronically controlled power take-off mechanism.

[0031] Engine power is transmitted to the power reversing mechanism via input shaft S1. When the driving direction needs to be changed, the hydraulic system engages the forward or reverse clutch, providing forward or reverse rotational power to output shaft S3. Simultaneously, the electronically controlled power take-off mechanism switches power to power take-off shaft S4 based on operational requirements. Hydraulic oil pump OP draws power through intermediate shaft S2 and supplies oil to various actuators. The hydraulic system synchronizes the operation of multiple clutches, achieving integrated operation of driving direction switching and power take-off control. This eliminates the need for parking, reversing, and manual clutch operation. During continuous operation, the driver can synchronize driving direction and power take-off status using electronic control commands, reducing power interruption time and significantly improving operational efficiency.

[0032] The input shaft S1, output shaft S3, and power take-off shaft S4 are coaxially arranged, and the power take-off shaft S4 is centrally disposed within the output shaft S3. Specifically, the power take-off shaft S4 passes through the output shaft S3 and has one end rotationally connected to the input shaft S1.

[0033] It should be noted that: the input shaft S1 is connected to the housing 1 through the first bearing B1, the output shaft S3 is connected to the housing 1 through the fourth bearing B4, the power take-off shaft S4 is coaxially installed with the input shaft S1 through the second bearing B2, and the power take-off shaft S4 is coaxially installed with the output shaft S3 through the third bearing B3.

[0034] The power take-off shaft S4 passes through the output shaft S3 and is rotationally connected to the input shaft S1 at one end. The power take-off shaft S4 is coaxially mounted with the input shaft S1 via a seventh bearing B7, and coaxially mounted with the output shaft S3 via a bearing. Compared to the prior art, the present invention's coaxial arrangement of the power take-off shaft S4 and the output shaft S3 reduces the axial layout space of the drive shaft assembly, making the entire transmission system more compact and reducing manufacturing costs. It also effectively reduces the axial length and radial volume of the transmission system, allowing the clutch mechanism to be centrally located at the shaft end connection. For example, in a tractor chassis layout, this design avoids spatial interference between the power take-off shaft S4 and the output shaft S3, reducing the structural complexity of the housing 1 while also reducing the number of bearing support points, facilitating maintenance operations.

[0035] It also includes an intermediate shaft S2, which is engaged with the input shaft S1 through gears for transmission.

[0036] The intermediate shaft S2 is connected to the housing 1 via a fifth bearing B5 and a sixth bearing B6 at both ends.

[0037] The power take-off shaft S4 is rotationally connected to the input shaft S1 and the output shaft S3 via bearings. The input shaft S1, intermediate shaft S2, output shaft S3, and power take-off shaft S4 are each mounted on the housing 1 via bearings and can rotate independently. The coaxial rotational connection of the input shaft S1, output shaft S3, and power take-off shaft S4 reduces lateral interference between the shafts during power transmission, reduces shaft wear, and improves the stability of the transmission system. While the shafts are assembled and connected to the housing 1 via bearings, the shafts are connected to each other via bearings, ensuring the coaxiality of the multiple shafts, which helps improve mechanical transmission efficiency. This application not only realizes power diversion by introducing an intermediate shaft S2 and gear meshing transmission, but also drives the hydraulic oil pump OP through the intermediate shaft S2, reducing the need for arranging additional power sources, and solving the problems of low transmission efficiency and hydraulic system dependence on external power caused by the lack of an intermediate shaft S2 in the traditional power reversing mechanism. Power diversion is achieved through gear meshing and cooperation with the intermediate shaft S2, reducing the load on the transmission chain, and providing integrated power input for the hydraulic control system, thereby improving the compactness and reliability of the transmission system.

[0038] The hydraulic control system includes a hydraulic oil pump OP, and the intermediate shaft S2 drives the hydraulic oil pump OP through a chain transmission mechanism.

[0039] The chain transmission mechanism includes: a first sprocket W1, fixed to the driving end of the hydraulic oil pump OP; a second sprocket W2, fixed to the intermediate shaft S2; a first chain CH1, which drives the first sprocket W1 and the second sprocket W2. The above connection method realizes the work of driving the hydraulic oil pump OP through the intermediate shaft S2. The power reversing mechanism includes a forward clutch and a reverse clutch, which are used to realize the same-direction power transmission and reverse power transmission between the output shaft S3 and the input shaft S1 respectively.

[0040] The power reversing mechanism transmits power between the intermediate shaft S2 and the output shaft S3 via a chain drive system. This system achieves forward and reverse rotation switching through a single transmission path, simplifying the shafting layout and reducing maintenance costs through the removable chain. This solves the problem of complex transmission systems and difficult maintenance during frequent reversals in agricultural machinery. The chain drive system achieves efficient power transmission in a compact layout, ensuring fast reversing response while improving the reliability of the transmission system in adverse conditions such as muddy and bumpy conditions and reducing the failure rate caused by wear of transmission components.

[0041] The chain drive system includes: a second sprocket W2, coaxially mounted on the intermediate shaft S2 via a bearing and capable of axial rotation relative to the intermediate shaft S2; a fourth sprocket W4, fixed to the output shaft S3; and a second chain CH2, connecting the third sprocket W3 and the fourth sprocket W4. The third sprocket W3 and the second chain CH2 connect the non-coaxial intermediate shaft S2 and the output shaft S3. In conjunction with the clutch system, power transmission is achieved, helping to reduce pressure on the intermediate shaft S2 and the output shaft S3 and stabilize the transmission efficiency of the intermediate shaft S2 and the output shaft S3. Through the coordinated control of the chain drive system and the clutch, switching operations can be completed without interrupting power transmission. The non-rigid contact characteristics of the chain drive reduce mechanical impact during switching, enabling flexible switching of the transmission path during power switching. This addresses the reliability issues caused by the parking operation and gear impact associated with traditional mechanical switching. It also simplifies the axial space occupied by the transmission system, meeting the requirements of a compact layout for agricultural machinery chassis.

[0042] The forward clutch includes: a fourth outer hub H4, connected to the output shaft S3; a third inner hub H3, connected to the input shaft S1, located on the inner side of the fourth outer hub H4; a forward friction plate group, integrated between the inner side of the fourth outer hub H4 and the outer side of the third inner hub H3; a second piston P2, used to control the engagement and disengagement of the forward friction plate group. When the forward friction plate group is engaged, the output shaft S3 and the input shaft S1 are fixed and rotate synchronously; a second return spring group SP2, used to push the second piston P2 back to its original position, so that the forward friction plate group is disengaged to cut off the power of the output shaft S3.

[0043] The forward friction plate group includes: the fourth active friction plate group CL4, connected to the third inner hub H3; the third driven friction plate group CL3, connected to the fourth outer hub H4; the second piston P2 is installed in the inner cavity of the fourth outer hub H4, and the second return spring group SP2 is in contact with the second piston P2 on one side and fixed to the fourth outer hub H4 on the other side. Through the control of the solenoid valve, the oil pressure established by the oil pump OP is introduced into the cavity of the second piston P2 and the fourth outer hub H4. The second piston P2 will push the third driven friction plate group CL3 and the fourth active friction plate group CL4 to combine, so that the output shaft S3 and the input shaft S1 are fixed and run together, and finally realize forward same-direction output; after the pressure oil in the second piston P2 is cut off by the solenoid valve, the second return spring group SP2 will push the second piston P2 back, so that the third driven friction plate group CL3 and the fourth active friction plate group CL4 are separated, thereby cutting off the output shaft S3. Power; The coaxial rotation connection between the input shaft S1 and the output shaft S3 helps to improve the contact stability when the third driven friction plate group CL3 and the fourth active friction plate group CL4 are combined, that is, the third driven friction plate group CL3 can maintain the same posture and close contact with the fourth active friction plate group CL4. On the one hand, it improves the efficiency of power transmission from the input shaft S1 to the output shaft S3. On the other hand, it reduces the severe local wear of the friction plate due to the tilted posture, reduces the possibility of friction plate damage caused by gear shifting during driving, improves driving safety, and reduces maintenance costs.

[0044] The reverse clutch includes: a sixth outer hub H6, connected to the intermediate shaft S2; a fifth inner hub H5, connected to the third sprocket W3, located on the inner side of the sixth outer hub H6; a reverse friction plate group, integrated between the inner side of the sixth outer hub H6 and the outer side of the fifth inner hub H5; a third piston P3, used to control the engagement and disengagement of the reverse friction plate group. When the reverse friction plate group is engaged, the intermediate shaft S2 and the sprocket W3 are fixed and rotate synchronously; a third return spring group SP3, used to push the third piston P3 back to its original position, so that the reverse friction plate group is disengaged to cut off the power of the output shaft S3.

[0045] The reverse gear friction plate group includes a fifth active friction plate group CL5 connected to the sixth outer hub H6 and a sixth driven friction plate group CL6 connected to the fifth inner hub H5. A third piston P3 is mounted within the inner cavity of the sixth outer hub H6. A third return spring group SP3 contacts the third piston P3 on one side and is fixed to the outer hub H6 on the other. A solenoid valve controls the oil pressure generated by the oil pump OP, which is introduced into the cavity of the third piston P3 and the sixth outer hub H6. The third piston P3 pushes the fifth active friction plate group CL5 and the sixth driven friction plate group CL6 together, securing the intermediate shaft S2 and the third sprocket W3 and ensuring their synchronous operation. This creates a reverse power flow between the output shaft S3 and the input shaft S1, ultimately achieving reverse gear output. When the solenoid valve shuts off the pressurized oil in the third piston P3, the third return spring group SP3 pushes the third piston P3 back, disengaging the fifth active friction plate group CL5 and the sixth driven friction plate group CL6, thereby shutting off power to the output shaft S3.

[0046] The electronically controlled power take-off mechanism includes a power take-off clutch, which is used to realize power transmission between the input shaft S1 and the power take-off shaft S4.

[0047] The power take-off clutch includes: a first outer hub H1 connected to the input shaft S1; a second inner hub H2 connected to the power take-off shaft S4 and located inside the first outer hub H1; a power take-off friction plate assembly integrated between the inside of the first outer hub H1 and the outside of the second inner hub H2; a first piston P1 used to control the engagement and disengagement of the power take-off friction plate assembly. When the power take-off friction plate assembly is engaged, the power from the input shaft S1 is transmitted in the same direction to the power take-off shaft S4; and a first return spring assembly SP1 used to push the first piston P1 back, disengaging the power take-off friction plate assembly and cutting off the power to the power take-off shaft (S4).

[0048] The power take-off friction plate group includes: a first active friction plate group CL1, connected to the first outer hub H1; a second driven friction plate group CL2, connected to the second inner hub H2; a first piston P1 is installed in the inner cavity of the first outer hub H1, and one side of the first return spring group SP1 is in contact with the first piston P1, and the other side is fixed to the first outer hub H1. Through the control of the solenoid valve, the oil pressure established by the oil pump OP is introduced into the cavity of the first piston P1 and the first outer hub H1. The first piston P1 will push the first active friction plate group CL1 and the second driven friction plate group CL2 to combine. At this time, the power of the input shaft S1 passes through the first outer hub H1, the first active friction plate group CL1, the second driven friction plate group CL2, and the second inner hub H2 in turn, and finally realizes the power transmission to the power take-off shaft S4; after the pressure oil in the first piston P1 is cut off through the control of the solenoid valve, the first return spring group SP1 will push the first piston P1 back The first active friction plate group CL1 and the second driven friction plate group CL2 are disengaged, thereby cutting off the power to the power take-off shaft S4. The through-hole arrangement of the power take-off shaft S4 and the output shaft S3 ensures that the various components of the power take-off clutch system can be relatively concentratedly arranged at the connection between the input shaft S1 and the power take-off shaft S4. This optimizes the spatial layout of the power take-off clutch system and reduces the axial length. On the one hand, this reduces the manufacturing cost of the power take-off clutch system, and on the other hand, it helps to shorten the extension and retraction stroke of the first piston P1, thereby improving the response speed of power transmission and cutting off. Since the power take-off shaft S4 passes through the output shaft S3 and is connected to the input shaft S1 through a bearing, the first outer hub H1 and the second inner hub H2 surround the outer periphery of the bearing at the connection point, which can realize the transition connection between the input shaft S1 and the power take-off shaft S4, further ensuring the coaxiality of the shaft rotation and reducing the power loss caused by shaking during the shaft rotation.

[0049] The second inner hub H2 surrounds the bearing connecting the input shaft S1 and the PTO shaft S4 to reduce lubricant leakage. This reduces lubricant loss in the bearings at the connection between the input shaft S1 and the PTO shaft S4, reducing the frequency of lubricant refills and lowering maintenance costs while ensuring smooth power transmission from the PTO shaft S4.

[0050] The coaxial, through-and-through arrangement of the PTO shaft S4 and output shaft S3 allows the clutch mechanism to be centrally located at the shaft connection. This allows the PTO clutch system and the reversing clutch system to be centrally located within the space between the input shaft S1, output shaft S3, and PTO shaft S4, where they rotate. The oil pressure generated by the oil pump OP quickly switches between the third piston P3 and the second piston P2, accelerating the shifting speed between forward and reverse gears and improving vehicle operation and driving efficiency.

[0051] The hydraulic control system controls the engagement and disengagement of the clutch through the solenoid valve.

[0052] The above-mentioned clutch reversing system only needs to input instructions to the oil pump OP to realize the function of automatically switching the driving direction of the vehicle while driving, as well as the automatic engagement and disengagement of the power take-off mechanism. That is, the power reversing and electronically controlled automatic power take-off of the transmission system can be realized through simple instructions. It not only realizes automatic control to improve work efficiency and reduce labor intensity, but also makes the structural scheme of the entire transmission system compact and reduces system costs through optimized structural design.

[0053] Example 2: The power reversing mechanism realizes power transmission between the intermediate shaft S2 and the output shaft S3 through the gear transmission system.

[0054] The gear transmission system includes: a first gear mounted on the output shaft S3; a second gear mounted on the intermediate shaft S2 via the seventh bearing B7; and an idler gear for connecting the first gear with the second gear to achieve co-directional rotation of the output shaft S3 and the intermediate shaft S2.

[0055] After adopting gear transmission, the power transmission loss from the intermediate shaft S2 to the output shaft S3 is reduced, and the overall power utilization rate of agricultural machinery is improved. Especially in long-term high-load operations, it can reduce fuel or electricity consumption and improve economy. The gear transmission solution is conducive to reducing noise pollution in the operating environment and improving the work experience of agricultural machinery operators. At the same time, it reduces the interference of vibration on other precision components and reduces the equipment failure rate.

[0056] Example 3: Based on Example 1 of the present invention, the fourth sprocket W4 includes a wheel body 20, which has an axial hole 21 for assembly with the output shaft S3. The wheel body 20 also has a mounting hole 22 arranged around the axial hole 21, and an elastically deformable auxiliary element 3 is inserted into the mounting hole 22. The auxiliary element 3 includes an outer shell 30 that cooperates with the mounting hole 22. The outer shell 30 is an elastic cylinder and has a hollow groove 31 arranged along the axis. A cylindrical pin 32 is installed in the hollow groove 31. It should be noted that the cylindrical pin 32 can squeeze the outer shell 30 under the action of inertia. The material of the cylindrical pin 32 includes but is not limited to metal. The mounting hole 22 includes two concentrically arranged first arcuate walls 221 radially disposed on opposite sides of the auxiliary element 3. The first arcuate walls 221 have the same radius as the outer casing 30. The mounting hole 22 also includes two second arcuate walls 222 disposed between and opposite the first arcuate walls 221. The centers of the two second arcuate walls 222 are located on either side of the center of the first arcuate walls 221, and the arc diameter of the second arcuate walls 222 is smaller than the outer diameter of the outer casing 30. A cylindrical pin 32 passes through the hollow slot 31 and has a stopper 33 at its end, which mates with the end surface of the wheel body 20. Under the operation of the clutch system, the power of the intermediate shaft is transmitted to the third sprocket W3, the second chain CH2, the fourth sprocket W4 and finally to the output shaft S3 to realize reverse gear power output. At this time, the fourth sprocket W4 rotates synchronously with the output shaft S3. There is mechanical interference in the process of the third sprocket W3 transmitting power to the fourth sprocket W4 through the second chain CH2. The mechanical interference can be buffered by the deformation of the outer shell, which is beneficial to improve the stability of the chain drive system power transmission in the case of sudden acceleration or braking; when it is necessary to switch quickly between forward gear and reverse gear, and the power output needs to be interrupted urgently, the fourth sprocket W4 and the output shaft S3 synchronously terminate the current rotation, and the cylindrical pin 32 in the first arc wall 22 maintains its original motion state due to its own inertia and squeezes the outer shell 30, so that the outer shell 30 moves toward the second arc wall 22 on one side. 2 internal deformation, further eliminating vibration interference, and improving the stability and centration of each sprocket and chain in the chain drive system; at the same time, since the outer shell 30 is fitted in the two first circular arc walls 221, that is, the outer shell 30 and the second circular arc walls 222 on both sides form intervals respectively, when the cylindrical pin 32 squeezes the outer shell 30 to deform, the outer shell 30 and the interval space on one side of the squeezing release airflow, which can blow air to the fourth outer hub H4 located on one side thereof, thereby cooling the fourth outer hub H4, thereby indirectly dissipating heat to the brake pad group on the inner side of the fourth outer hub H4, that is, automatically cooling and dissipating heat to the brake pad group during braking and power shifting, on the one hand, improving the braking effect of the brake pad group, on the other hand, reducing the possibility of damage to the brake pad group due to excessive wear caused by high temperature, extending the working life of the brake pad group, and improving braking safety.Since the second arc walls 222 are arranged in opposite directions, the outer shell can be deformed and squeezed in the gap space on the corresponding side regardless of reverse braking or forward braking to achieve exhaust and heat dissipation, that is, it can improve the braking efficiency of reverse braking and the braking efficiency of forward braking, thereby improving the vehicle operating efficiency.

[0057] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above and that the invention can be embodied in other specific forms without departing from the spirit or essential characteristics of the invention. Therefore, the embodiments should be considered in all respects as illustrative and non-restrictive, and the scope of the invention is defined by the appended claims, not the foregoing description, and all variations within the meaning and range of equivalents of the claims are intended to be included therein. Any reference sign in a claim should not be construed as limiting the claim to which it relates.

Claims

1. A power reversing transmission mechanism for agricultural machinery with automatic power take-off switching, characterized in that: include: Input shaft (S1); Output shaft (S3); Power take-off shaft (S4); A power reversing mechanism for switching the power direction of the output shaft (S3); an electronically controlled power take-off mechanism for controlling the power transmission of the power take-off shaft (S4); The hydraulic control system is used to drive the power reversing mechanism and the electronically controlled power take-off mechanism.

2. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, characterized in that: The input shaft (S1), the output shaft (S3) and the power take-off shaft (S4) are coaxially arranged, and the power take-off shaft (S4) is centrally arranged in the output shaft (S3).

3. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, characterized in that: It also includes an intermediate shaft (S2), which is engaged with the input shaft (S1) through gears.

4. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 3, characterized in that: The hydraulic control system includes a hydraulic oil pump (OP), and the intermediate shaft (S2) drives the hydraulic oil pump (OP) through a chain transmission mechanism.

5. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 4, characterized in that: The chain transmission mechanism comprises: a first sprocket (W1) fixed to a driving end of the hydraulic oil pump (OP); a second sprocket (W2) fixed to the intermediate shaft (S2); A first chain (CH1) transmission-connects the first sprocket (W1) and the second sprocket (W2).

6. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 3, characterized in that: The power reversing mechanism comprises a forward gear clutch and a reverse gear clutch, which are respectively used to realize the same-direction power transmission and reverse power transmission between the output shaft (S3) and the input shaft (S1).

7. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 6, characterized in that: The power reversing mechanism realizes power transmission between the intermediate shaft (S2) and the output shaft (S3) through a chain transmission system.

8. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 7, characterized in that: The chain transmission system comprises: A third sprocket (W3) is coaxially mounted on the intermediate shaft (S2) via a seventh bearing (B7) and is axially rotatable relative to the intermediate shaft (S2); a fourth sprocket (W4), fixed to the output shaft (S3); The second chain (CH2) connects the third sprocket (W3) and the fourth sprocket (W4).

9. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 6, characterized in that: The forward clutch comprises: a fourth outer hub (H4), connected to the output shaft (S3); a third inner hub (H3), connected to the input shaft (S1) and located inside the fourth outer hub (H4); A forward friction plate group is integrated between the inner side of the fourth outer hub (H4) and the outer side of the third inner hub (H3); a second piston (P2) for controlling the engagement and disengagement of the forward friction plate group; when the forward friction plate group is engaged, the output shaft (S3) and the input shaft (S1) are fixed and rotate synchronously; The second return spring assembly (SP2) is used to push the second piston (P2) back to its original position, so as to separate the forward friction plate assembly and cut off the power of the output shaft (S3).

10. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 9, characterized in that: The forward friction plate group comprises: a fourth active friction plate group (CL4) connected to the third inner hub (H3); The third driven friction plate group (CL3) is connected to the fourth outer hub (H4), the second piston (P2) is installed in the inner cavity of the fourth outer hub (H4), and one side of the second return spring group (SP2) is in contact with the second piston (P2) and the other side is fixed to the fourth outer hub (H4).

11. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 8, characterized in that: The reverse clutch comprises: a sixth outer hub (H6), connected to the intermediate shaft (S2); a fifth inner hub (H5), connected to the third sprocket (W3), and located inside the sixth outer hub (H6); A reverse gear friction plate group is integrated between the inner side of the sixth outer hub (H6) and the outer side of the fifth inner hub (H5); A third piston (P3) is used to control the engagement and disengagement of the reverse gear friction plate group. When the reverse gear friction plate group is engaged, the intermediate shaft (S2) and the sprocket (W3) are fixed and rotate synchronously. The third return spring assembly (SP3) is used to push the third piston (P3) back to its original position, so as to separate the reverse gear friction plate assembly and cut off the power of the output shaft (S3).

12. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 11, characterized in that: The reverse gear friction plate group includes: a fifth active friction plate group (CL5) connected to the sixth outer hub (H6); The sixth driven friction plate group (CL6) is connected to the fifth inner hub (H5), the third piston (P3) is installed in the inner cavity of the sixth outer hub (H6), and one side of the third return spring group (SP3) is in contact with the third piston (P3) and the other side is fixed to the sixth outer hub (H6).

13. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, characterized in that: The electronically controlled power take-off mechanism comprises a power take-off clutch, and the power take-off clutch is used to realize power transmission between the input shaft (S1) and the power take-off shaft (S4).

14. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 13, characterized in that: The power take-off clutch comprises: a first outer hub (H1) connected to the input shaft (S1); a second inner hub (H2), connected to the power take-off shaft (S4), and located inside the first outer hub (H1); The power take-off friction plate group is integrated between the inner side of the first outer hub (H1) and the outer side of the second inner hub (H2). between; A first piston (P1) is used to control the engagement and disengagement of the power take-off friction plate group. When the power take-off friction plate group is engaged, the power of the input shaft (S1) is transmitted to the power take-off shaft (S4) in the same direction. The first return spring assembly (SP1) is used to push the first piston (P1) back to its original position, so as to separate the power take-off friction plate assembly and cut off the power of the power take-off shaft (S4).

15. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 14, characterized in that: The power take-off friction plate group includes: A first active friction plate group (CL1) is connected to the first outer hub (H1); A second driven friction plate group (CL2) is connected to the second inner hub (H2); The first piston (P1) is installed in the inner cavity of the first outer hub (H1); one side of the first return spring assembly (SP1) is in contact with the first piston (P1) and the other side is fixed to the first outer hub (H1).

16. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 14, characterized in that: The second inner hub (H2) surrounds the connecting bearings of the input shaft (S1) and the power take-off shaft (S4), so that all the lubricating oil passing through the connecting bearings acts on the power take-off friction plate group.

17. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 13, characterized in that: The through-coaxial arrangement of the power take-off shaft (S4) and the output shaft (S3) enables the clutch mechanism to be centrally arranged at the shaft connection.

18. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, characterized in that: The hydraulic control system controls the engagement and disengagement of the clutch through a solenoid valve.

19. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 6, characterized in that: The power reversing mechanism realizes power transmission between the intermediate shaft (S2) and the output shaft (S3) through a gear transmission system.

20. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 19, characterized in that: The gear transmission system comprises: a first gear mounted on the output shaft (S3); A second gear is mounted on the intermediate shaft (S2) via a seventh bearing (B7); The idler gear is used for transmission connection between the first gear and the second gear to achieve the same-direction rotation of the output shaft (S3) and the intermediate shaft (S2).

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