Power take-off automatic switching agricultural power reversing transmission mechanism

Abstract

The application discloses a power automatic switching agricultural machine power reversing transmission mechanism and belongs to the technical field of gearboxes. The transmission mechanism comprises an input shaft, an output shaft, a power taking shaft, a power reversing mechanism for switching the power direction of the output shaft, an electric control power taking mechanism for controlling the power transmission of the power taking shaft and a hydraulic control system for driving the power reversing mechanism and the electric control power taking mechanism. The application can realize automatic switching of forward and backward movement, automatic output and automatic cutting of power during the reversing process, improves work efficiency and reduces labor intensity.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of transmission, and particularly relates to a power automatic switching agricultural machine power reversing transmission mechanism. BACKGROUND

[0002] At present, tractors or similar agricultural power machines generally adopt dry main clutches matched with mechanical separation structures. When the gears are changed, the driving direction is changed or the power take-off mechanism is switched, the clutch pedal needs to be stepped on to cut off the power transmitted from the engine, and then the required gear or the combination and separation of the power take-off mechanism is selected through the mechanical gear lever. When the driving direction is changed, not only the clutch pedal needs to be stepped on, but also the vehicle needs to be stopped before the forward / reverse switching is performed. Moreover, when the driving direction is changed, the power take-off mechanism needs to be separated from the power output, and the clutch pedal also needs to be stepped on to realize the separation. The whole operation process is complicated and laborious. Especially when a small plot is worked, the driving direction needs to be frequently changed, which puts high requirements on the working strength of the driver. Moreover, the vehicle needs to be stopped before the driving direction is changed, which greatly reduces the working efficiency.

[0003] In view of the above status, in recent years, the domestic agricultural machinery industry vigorously promotes the development of power reversing technology. An application No. CN202322913002.7 discloses a tractor power reversing assembly, and an application No. CN202322015249.7 discloses a tractor power reversing transmission device. Both of them realize the power reversing function through different combination modes of two groups of clutches. However, since the power take-off mechanism also needs to be frequently switched in use, and the agricultural machine chassis has high requirements on the structure and arrangement of the transmission system, a highly integrated product is needed to simultaneously meet the functional requirements of power reversing and automatic switching of the power take-off mechanism, and the highly integrated product meets the arrangement requirements and promotes the progress of modern agricultural technology.

[0004] An application No. US18608684 discloses a transmission system for a hybrid drive unit. The system includes a centrifugal clutch connected to a driven shaft and connectable to an electric machine, and a clutch slider element connected to a rotor of the electric machine and slidable relative to the centrifugal clutch between three engagement positions. The transmission system further includes a clutch override assembly for rotatably connecting the centrifugal clutch and the clutch slider element to provide continuous torque transfer to the driven shaft when switching between a pure electric drive mode and at least one hybrid drive mode. The invention can realize rapid power transmission. However, in the prior art, the agricultural machine needs to frequently change the power direction during work, and the reversing operation is relatively complicated. The above-mentioned US18608684 patent does not solve the problem. SUMMARY

[0005] The application aims to provide a highly integrated agricultural power reversing transmission mechanism with high transmission efficiency and simple reversing operation.

[0006] The application adopts the following technical scheme to achieve the above-mentioned purpose:

[0007] The application discloses an automatic power switching agricultural power reversing transmission mechanism, which 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 electrically-controlled power take-off mechanism for controlling the power transmission of the power take-off shaft, and a hydraulic control system for driving the power reversing mechanism and the electrically-controlled power take-off mechanism. The power of an engine is transmitted to the power reversing mechanism through the input shaft. When it is necessary to change the driving direction, the hydraulic system drives the forward gear or the reverse gear clutch to be engaged, so that the output shaft obtains positive or reverse rotating power. Meanwhile, the electrically-controlled power take-off mechanism controls the power on-off of the power take-off shaft according to the operation requirement. The hydraulic oil pump obtains power through the intermediate shaft and supplies oil to each execution element. The hydraulic system synchronously controls the actions of multiple clutches, realizes the integrated operation of the driving direction switching and the power take-off control, eliminates the operation links of parking reversing and manual clutch stepping, and enables the driver to synchronously switch the driving direction and the power take-off state through the electrically-controlled instruction in the continuous operation process, reduces the power interruption time, and significantly improves the operation efficiency.

[0008] Preferably, the input shaft, the output shaft and the power take-off shaft are coaxially arranged, and the power take-off shaft is arranged in the output shaft in a penetrating mode. The power take-off shaft penetrates the output shaft and is rotationally connected to the input shaft at one end. The power take-off shaft is coaxially installed with the input shaft through the seventh bearing, and is coaxially installed with the output shaft through the bearing. Compared with the prior art, the power take-off shaft and the output shaft are coaxially arranged in a penetrating mode, which reduces the layout space of the transmission shaft group in the axial direction, makes the structure of the whole transmission system compact, reduces the manufacturing cost of the system, effectively reduces the axial length and the radial volume of the transmission system, and enables the clutch mechanism to be concentratedly arranged at the shaft end connection, for example, in the layout of a tractor chassis. The design can avoid the space interference between the power take-off shaft and the output shaft, reduces the complexity of the shell structure, reduces the number of bearing support points, and facilitates maintenance operation.

[0009] Preferably, the application further comprises an intermediate shaft, and the intermediate shaft is in gear meshing transmission with the input shaft. The power take-off shaft is rotationally connected to the input shaft and the output shaft through bearings. The input shaft, the intermediate shaft, the output shaft and the power take-off shaft are respectively installed on the shell through bearings and can independently rotate. The coaxial rotation connection of the input shaft, the output shaft and the power take-off shaft reduces the side interference between the shafts in the power transmission process, reduces the wear of the shafts, and improves the stability of the transmission system. The shafts are assembled and connected to the shell through bearings, and the shafts are connected through bearings, so that the coaxiality of the shafts is ensured, and the mechanical transmission efficiency is improved.

[0010] The application realizes power split by introducing an intermediate shaft and gear meshing transmission, drives a hydraulic oil pump through the intermediate shaft, reduces the layout requirement of an additional power source, solves the problems of low transmission efficiency and external power dependence of the hydraulic system caused by the lack of an intermediate shaft in the traditional power reversing mechanism, realizes power split through gear meshing and cooperation with the intermediate shaft, reduces the load of the transmission chain, provides integrated power input for the hydraulic control system, and improves the compactness and reliability of the transmission system.

[0011] Preferably, the hydraulic control system comprises a hydraulic oil pump, and the intermediate shaft drives the hydraulic oil pump through the chain transmission mechanism.

[0012] Preferably, the chain transmission mechanism comprises 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 transmission connecting the first sprocket and the second sprocket. The above connection mode realizes the driving of the hydraulic oil pump by the intermediate shaft

[0013] Preferably, the power reversing mechanism comprises a forward clutch and a reverse clutch, which are respectively used to realize the same direction power transmission and reverse power transmission of the output shaft and the input shaft.

[0014] Preferably, the power reversing mechanism realizes the power transmission between the intermediate shaft and the output shaft through the chain transmission system. The chain transmission system realizes forward and reverse rotation switching through a single transmission path, not only simplifies the shaft layout, but also reduces the maintenance cost through the detachable characteristics of the chain, solves the problems of complex structure and difficult maintenance of the transmission system during frequent reversing of agricultural machinery, realizes efficient power transmission under compact layout through the chain transmission system, ensures the reversing response speed, improves the reliability of the transmission system in harsh working conditions such as mud and bumps, and reduces the failure rate caused by the wear of transmission parts.

[0015] Preferably, the chain transmission system comprises a second sprocket coaxially installed on the intermediate shaft through a bearing and capable of rotating axially 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 third sprocket and the second chain realize the connection of the non-coaxial intermediate shaft and the output shaft, cooperate with the clutch system to realize the transmission of power, help 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 realize the flexible switching of the transmission path during power reversing through the cooperative control of the chain transmission system and the clutch. At the same time, the non-rigid contact characteristics of the chain transmission reduce the mechanical impact in the reversing process, solve the reliability problems caused by the need for parking operation and gear impact in the traditional mechanical reversing, simplify the axial space occupation of the transmission system, and adapt to the demand for compact layout of the agricultural machinery chassis.

[0016] Preferably, the forward clutch comprises: a fourth outer hub connected with the output shaft; a third inner hub connected with the input shaft and located inside the fourth outer hub; a forward friction plate set integrated between the inside of the fourth outer hub and the outside of the third inner hub; a second piston for controlling the combination and separation of the forward friction plate set, the output shaft and the input shaft fixed and synchronously rotating when the forward friction plate set is combined; and a second return spring set for pushing the second piston back to separate the forward friction plate set to cut off the power of the output shaft.

[0017] Preferably, the forward friction plate set comprises: a fourth driving friction plate set connected with the third inner hub; a third driven friction plate set connected with the fourth outer hub; the second piston is installed in the inner cavity of the fourth outer hub, one side of the second return spring set is in contact with the second piston, and the other side is fixed to the fourth outer hub. Through the control of the electromagnetic 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 set and the fourth driving friction plate set to combine, realizing the fixed rotation of the output shaft and the input shaft together, and finally realizing the forward same direction output; after the pressure oil in the second piston is cut off by the electromagnetic valve, the second return spring set will push the second piston back to separate the third driven friction plate set and the fourth driving friction plate set, thereby cutting off the power of the output shaft; the coaxial rotation connection of the input shaft and the output shaft helps to improve the contact stability of the third driven friction plate set and the fourth driving friction plate set when they are combined, that is, the third driven friction plate set can maintain the same posture and closely contact with the fourth driving friction plate set, on the one hand, it improves the transmission efficiency of the power from the input shaft to the output shaft, on the other hand, it reduces the local serious wear of the friction plate caused by the posture tilt, reduces the possibility of friction plate damage caused by shifting in the driving process, improves the driving safety, and reduces the maintenance cost.

[0018] Preferably, the reverse clutch comprises: a sixth outer hub connected with the intermediate shaft; a fifth inner hub connected with the third sprocket and located inside the sixth outer hub; a reverse friction plate set integrated between the inside of the sixth outer hub and the outside of the fifth inner hub; a third piston for controlling the combination and separation of the reverse friction plate set, the intermediate shaft and the sprocket fixed and synchronously rotating when the reverse friction plate set is combined; and a third return spring set for pushing the third piston back to separate the reverse friction plate set to cut off the power of the output shaft.

[0019] Preferably, the reverse friction plate set comprises: a fifth driving friction plate set connected with the sixth outer hub; a sixth driven friction plate set connected with the fifth inner hub; a third piston installed in the inner cavity of the sixth outer hub, and a third return spring set in contact with one side of the third piston and fixed to the other side of the sixth outer hub. Through the control of the electromagnetic valve, the oil pressure established by the oil pump is introduced into the cavity of the third piston and the sixth outer hub, and the third piston will push the fifth driving friction plate set and the sixth driven friction plate set to combine, so as to realize the fixation and synchronous operation of the intermediate shaft and the third sprocket, thereby realizing the reverse output of the power between the output shaft and the input shaft, and finally realizing the reverse output; after the pressure oil in the third piston is cut off by the electromagnetic valve, the third return spring set will push the third piston to return to the original position, so that the fifth driving friction plate set and the sixth driven friction plate set are separated, thereby cutting off the power of the output shaft.

[0020] Preferably, the electrically controlled power take-off mechanism comprises a power take-off clutch for realizing the power transmission between the input shaft and the power take-off shaft.

[0021] Preferably, the power take-off clutch comprises: a first outer hub connected with the input shaft; a second inner hub connected with the power take-off shaft and located inside the first outer hub; a power take-off friction plate set integrated between the inside of the first outer hub and the outside of the second inner hub; a first piston for controlling the combination and separation of the power take-off friction plate set, and when the power take-off friction plate set is combined, the power of the input shaft is transmitted to the power take-off shaft in the same direction; and a first return spring set for pushing the first piston to return to the original position, so as to separate the power take-off friction plate set and cut off the power of the power take-off shaft.

[0022] Preferably, the power take-off friction plate set comprises: a first driving friction plate set connected with the first outer hub; a second driven friction plate set connected with the second inner hub; a first piston installed in the inner cavity of the first outer hub, and a first return spring set in contact with one side of the first piston and fixed to the other side of the first outer hub. Through the control of the electromagnetic valve, the oil pressure established by the oil pump is introduced into the cavity of the first piston and the first outer hub, and the first piston will push the first driving friction plate set and the second driven friction plate set to combine, at this time the power of the input shaft will pass through the first outer hub, the first driving friction plate set, the second driven friction plate set and the second inner hub in sequence, and finally realize the power transmission to the power take-off shaft; after the pressure oil in the first piston is cut off by the electromagnetic valve, the first return spring set will push the first piston to return to the original position, so that the first driving friction plate set and the second driven friction plate set are separated, thereby cutting off the power of the power take-off shaft; the through arrangement of the power take-off shaft and the output shaft ensures that all 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, that is, the spatial layout of the power take-off clutch system is optimized, the axial arrangement length is reduced, on the one hand the manufacturing cost of the power take-off clutch system is reduced, and on the other hand it is helpful to reduce the stroke amplitude of the first piston in pushing and retracting, thereby improving the response speed of power transmission and cut-off;

[0023] The first outer hub and the second inner hub are arranged around the bearing at the connection position, so that the transition connection between the input shaft and the power take-off shaft is achieved, the coaxiality of the shaft rotation is further ensured, and the power loss caused by shaking during the rotation of the shaft is reduced.

[0024] Preferably, the second inner hub surrounds the connecting bearing of the input shaft and the power take-off shaft, so that the lubricating oil passing through the connecting bearing is entirely used for the power take-off friction plate set. The second inner hub can reduce the loss of lubricating oil of the connecting bearing of the input shaft and the power take-off shaft, reduce the lubricating oil addition frequency, reduce the maintenance cost, increase the lubricating oil flow of the friction plate set, strengthen the heat dissipation efficiency, reduce the wear or ablation risk of the friction plate caused by high temperature, ensure the smoothness of the power transmission of the power take-off shaft, and form a lubricating oil guide channel by surrounding the bearing, so that the lubricating oil after lubricating the bearing is entirely guided to the power take-off friction plate set, lubricating the bearing and the friction plate, reducing the design requirement of the independent lubricating oil path, and reducing the complexity and cost of the lubricating system.

[0025] The structure of the second inner hub surrounding the bearing can form a ring-shaped uniform guide, so that the lubricating oil of the bearing flows uniformly into the power take-off friction plate set from all around, the lubricating oil is more uniformly distributed on the surface of the power take-off friction plate, the local wear is reduced, and the service life of the power take-off friction plate is prolonged.

[0026] Preferably, the through and coaxial arrangement of the power take-off shaft and the output shaft enables the clutch mechanism to be arranged at the shaft connection position. Since the power take-off shaft and the output shaft are arranged in a through and coaxial manner, the power take-off clutch system and the reversing clutch system can be arranged at the space at the rotating connection position of the input shaft, the output shaft and the power take-off shaft, the oil pressure established by the oil pump can be quickly switched between the third piston and the second piston, that is, the corresponding rate of the gear shifting between the forward gear and the reverse gear is accelerated, which helps to improve the efficiency of the vehicle operation and the vehicle driving.

[0027] Preferably, the hydraulic control system controls the combination and separation of the clutch through the electromagnetic valve.

[0028] Preferably, the power reversing mechanism realizes the power transmission between the intermediate shaft and the output shaft through the gear transmission system.

[0029] Preferably, the gear transmission system comprises: a first gear installed on the output shaft; a second gear installed on the intermediate shaft through a seventh bearing; and an idler gear used for the transmission connection between the first gear and the second gear, so as to realize the same direction rotation of the output shaft and the intermediate shaft.

[0030] 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.

[0031] 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

[0032] 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;

[0033] Figure 2 for Figure 1 A magnified schematic diagram of area A in the middle;

[0034] Figure 3 for Figure 1 A magnified schematic diagram of area B in the middle;

[0035] Figure 4 Schematic diagram of the structure of the fourth sprocket W4;

[0036] Figure 5 is a partial cross-sectional schematic diagram of the fourth sprocket W4;

[0037] Figure 6 It is a cross-sectional schematic diagram of the fourth W4 sprocket and auxiliary parts.

[0038] Fig. 1: 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 set SP1; first driving friction plate set CL1; second driven friction plate set CL2; first piston P1; fourth outer hub H4; third inner hub H3; second return spring set SP2; fourth driving friction plate set CL4; third driven friction plate set CL3; second piston P2; sixth outer hub H6; fifth inner hub H5; third return spring set SP3; fifth driving friction plate set CL5; sixth driven friction plate set 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 sleeve body 30; hollow groove 31; cylindrical pin 32; limiting portion 33. DETAILED DESCRIPTION

[0039] The technical solutions of the present application will be further described in detail below in combination with the specific embodiments and the drawings:

[0040] Obviously, the described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work shall fall within the protection scope of the present application.

[0041] Embodiment one:

[0042] A power take-off automatic switching agricultural machinery power reversing transmission mechanism, comprising: 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 electric control power take-off mechanism for controlling the power transmission of the power take-off shaft S4; a hydraulic control system for driving the power reversing mechanism and the electric control power take-off mechanism.

[0043] The engine power is transmitted to the power reversing mechanism through the input shaft S1. When it is necessary to change the driving direction, the hydraulic system drives the forward gear or the reverse gear clutch to engage, so that the output shaft S3 obtains forward or reverse rotating power. At the same time, the electric control power take-off mechanism controls the power on-off of the power take-off shaft S4 according to the operation requirement, the hydraulic oil pump OP obtains power through the intermediate shaft S2 and supplies oil to each executing element, and through the synchronous control of the hydraulic system, the action of multiple clutches is realized, the integrated operation of the driving direction switching and the power take-off control is realized, the operation links of parking reversing and manual clutch stepping are eliminated, and in the continuous operation process, the driver can synchronously switch the driving direction and the power take-off state through the electric control instruction, the power interruption time is reduced, and the operation efficiency is significantly improved.

[0044] 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 arranged in the output shaft S3. Specifically, the power take-off shaft S4 passes through the output shaft S3 and is rotatably connected to the input shaft S1 at one end.

[0045] 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.

[0046] The power take-off shaft S4 passes through the output shaft S3 and is rotatably connected to the input shaft S1 at one end, the power take-off shaft S4 is coaxially installed with the input shaft S1 through the seventh bearing B7, and the power take-off shaft S4 is coaxially installed with the output shaft S3 through the bearing. Compared with the prior art, the power take-off shaft S4 and the output shaft S3 are coaxially arranged, which reduces the layout space of the transmission shaft group in the axial direction, makes the structure of the entire transmission system compact, reduces the manufacturing cost of the system, effectively reduces the axial length and radial volume of the transmission system, and enables the clutch mechanism to be concentratedly arranged at the shaft end connection, for example, in the layout of the tractor chassis. This design can avoid the space interference between the power take-off shaft S4 and the output shaft S3, reduce the complexity of the housing 1 structure, reduce the number of bearing support points, and facilitate maintenance and operation.

[0047] It also includes an intermediate shaft S2, which is driven by gear meshing with the input shaft S1.

[0048] The intermediate shaft S2 is connected to the housing 1 through the fifth bearing B5 and the sixth bearing B6 at both ends.

[0049] The power take-off shaft S4 is rotatably connected to the input shaft S1 and the output shaft S3 through bearings, respectively. The input shaft S1, the intermediate shaft S2, the output shaft S3 and the power take-off shaft S4 are each installed on the housing 1 through bearings and can each independently rotate. The coaxial rotation connection of the input shaft S1, the output shaft S3 and the power take-off shaft S4 reduces the side interference between the shafts during power transmission, reduces the wear of the shafts, improves the stability of the transmission system, and ensures the coaxiality of the multiple shafts through the bearing connection between the shafts, which helps to improve the mechanical transmission efficiency.

[0050] The present application introduces the intermediate shaft S2 and the gear meshing transmission, which not only realizes power splitting, but also drives the hydraulic oil pump OP through the intermediate shaft S2, reduces the layout requirement of the additional power source, solves the problems of low transmission efficiency and dependence on external power of the traditional power reversing mechanism due to the lack of intermediate shaft S2, realizes power splitting through gear meshing and cooperation with the intermediate shaft S2, reduces the load of the transmission chain, and provides integrated power input for the hydraulic control system, thereby improving the compactness and reliability of the transmission system.

[0051] The hydraulic control system comprises a hydraulic oil pump OP, and the intermediate shaft S2 drives the hydraulic oil pump OP through a chain transmission mechanism.

[0052] The chain transmission mechanism comprises 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, and a first chain CH1 connecting the first sprocket W1 and the second sprocket W2. The connection mode realizes the driving of the hydraulic oil pump OP by the intermediate shaft S2

[0053] The power reversing mechanism comprises a forward clutch and a reverse clutch, which are used to realize the same direction power transmission and reverse power transmission of the output shaft S3 and the input shaft S1, respectively.

[0054] The power reversing mechanism realizes the power transmission between the intermediate shaft S2 and the output shaft S3 through a chain transmission system. The chain transmission system realizes forward and reverse rotation switching through a single transmission path, which not only simplifies the shaft layout, but also reduces the maintenance cost through the detachable characteristics of the chain, solves the problems of complex transmission system structure and difficult maintenance of agricultural machinery during frequent reversing, realizes efficient power transmission under compact layout through the chain transmission system, ensures the reversing response speed, improves the reliability of the transmission system in muddy and bumpy harsh conditions, and reduces the failure rate caused by transmission component wear.

[0055] The chain transmission system comprises a second sprocket W2 coaxially installed on the intermediate shaft S2 through a bearing and capable of rotating axially 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 realize the connection of the non-coaxial intermediate shaft S2 and the output shaft S3, cooperate with the clutch system to realize the power transmission, help to reduce the pressure acting on the intermediate shaft S2 and the output shaft S3, stabilize the transmission efficiency of the intermediate shaft S2 and the output shaft S3, and realize the flexible switching of the transmission path during the power reversing process through the cooperative control of the chain transmission system and the clutch. The non-rigid contact characteristics of the chain transmission reduce the mechanical impact in the reversing process, solve the reliability problems caused by the need for parking operation and gear impact in traditional mechanical reversing, simplify the axial space occupation of the transmission system, and adapt to the demand of compact layout of the agricultural machine chassis.

[0056] The forward clutch comprises: a fourth outer hub H4 connected with the output shaft S3; a third inner hub H3 connected with the input shaft S1 and located inside the fourth outer hub H4; a forward friction plate set integrated between the inside of the fourth outer hub H4 and the outside of the third inner hub H3; a second piston P2 for controlling the combination and separation of the forward friction plate set, the output shaft S3 and the input shaft S1 fixedly and synchronously rotate when the forward friction plate set is combined; and a second return spring set SP2 for pushing the second piston P2 to return and separating the forward friction plate set to cut off the power of the output shaft S3.

[0057] The forward friction plate set comprises: a fourth driving friction plate set CL4 connected with the third inner hub H3; a third driven friction plate set CL3 connected with the fourth outer hub H4; the second piston P2 is installed in the inner cavity of the fourth outer hub H4, one side of the second return spring set SP2 is in contact with the second piston P2, and the other side is fixed to the fourth outer hub H4. Through the control of the electromagnetic valve, the oil pressure established by the oil pump OP is introduced into the cavities of the second piston P2 and the fourth outer hub H4, the second piston P2 pushes the third driven friction plate set CL3 and the fourth driving friction plate set CL4 to combine, realizes the fixed rotation of the output shaft S3 and the input shaft S1 together, and finally realizes the forward same-direction output; after the pressure oil in the second piston P2 is cut off by the electromagnetic valve, the second return spring set SP2 pushes the second piston P2 to return, so that the third driven friction plate set CL3 and the fourth driving friction plate set CL4 are separated, thereby cutting off the power of the output shaft S3; the coaxial rotation connection of the input shaft S1 and the output shaft S3 helps to improve the contact stability when the third driven friction plate set CL3 and the fourth driving friction plate set CL4 are combined, that is, the third driven friction plate set CL3 can keep the same posture and closely contact with the fourth driving friction plate set CL4, on the one hand, the transmission efficiency of the power from the input shaft S1 to the output shaft S3 is improved, on the other hand, the local serious wear of the friction plate caused by the posture inclination is reduced, the possibility of damage of the friction plate caused by shifting in the driving process is reduced, the driving safety is improved, and the maintenance cost is reduced.

[0058] The reverse clutch comprises: a sixth outer hub H6 connected with the intermediate shaft S2; a fifth inner hub H5 connected with the third sprocket W3 and located inside the sixth outer hub H6; a reverse friction plate set integrated between the inside of the sixth outer hub H6 and the outside of the fifth inner hub H5; a third piston P3 for controlling the combination and separation of the reverse friction plate set, the intermediate shaft S2 and the sprocket W3 fixedly and synchronously rotate when the reverse friction plate set is combined; and a third return spring set SP3 for pushing the third piston P3 to return and separating the reverse friction plate set to cut off the power of the output shaft S3.

[0059] The reverse friction plate set comprises: a fifth driving friction plate set CL5 connected with a sixth outer hub H6; a sixth driven friction plate set CL6 connected with a fifth inner hub H5; a third piston P3 installed in the inner cavity of the sixth outer hub H6, and a third return spring set SP3 in contact with one side of the third piston P3 and fixed to the other side of the sixth outer hub H6. Through the control of the electromagnetic valve, the oil pressure established by the oil pump OP is introduced into the cavity of the third piston P3 and the sixth outer hub H6, and the third piston P3 will push the fifth driving friction plate set CL5 and the sixth driven friction plate set CL6 to combine, so as to realize the fixation and synchronous operation of the intermediate shaft S2 and the third sprocket W3, thereby realizing the reverse output of power between the output shaft S3 and the input shaft S1, and finally realizing the reverse output; after the pressure oil in the third piston P3 is cut off by the electromagnetic valve, the third return spring set SP3 will push the third piston P3 back to its original position, so that the fifth driving friction plate set CL5 and the sixth driven friction plate set CL6 are separated, thereby cutting off the power of the output shaft S3.

[0060] The electrically controlled power take-off mechanism comprises a power take-off clutch for realizing the power transmission between the input shaft S1 and the power take-off shaft S4.

[0061] The power take-off clutch comprises: a first outer hub H1 connected with the input shaft S1; a second inner hub H2 connected with the power take-off shaft S4 and located inside the first outer hub H1; a power take-off friction plate set integrated between the inside of the first outer hub H1 and the outside of the second inner hub H2; a first piston P1 for controlling the combination and separation of the power take-off friction plate set, when the power take-off friction plate set is combined, the power of the input shaft S1 is transmitted to the power take-off shaft S4 in the same direction; and a first return spring set SP1 for pushing the first piston P1 back to its original position to separate the power take-off friction plate set and cut off the power of the power take-off shaft S4.

[0062] The power take-off friction plate set comprises: a first driving friction plate set CL1 connected with the first outer hub H1; a second driven friction plate set CL2 connected with the second inner hub H2; a first piston P1 installed in the inner cavity of the first outer hub H1, and a first return spring set SP1 in contact with one side of the first piston P1 and fixed to the other side of the first outer hub H1. Through the control of the electromagnetic 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, and the first piston P1 will push the first driving friction plate set CL1 and the second driven friction plate set CL2 to combine, at this time, the power of the input shaft S1 passes through the first outer hub H1, the first driving friction plate set CL1, the second driven friction plate set CL2, and the second inner hub H2 in sequence, and finally realizes 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 electromagnetic valve, the first return spring set SP1 will push the first piston P1 back to its original position, so that the first driving friction plate set CL1 and the second driven friction plate set CL2 are separated, thereby cutting off the power of the power take-off shaft S4; The through arrangement of the power take-off shaft S4 and the output shaft S3 ensures that all 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, that is, the spatial layout of the power take-off clutch system is optimized, the axial arrangement length is reduced, on the one hand, the manufacturing cost of the power take-off clutch system is reduced, on the other hand, it helps to reduce the stroke amplitude of the first piston P1 in pushing and retracting, and improves the response speed of power transmission and cut-off;

[0063] Since the power take-off shaft S4 passes through the bearing connection between the output shaft S3 and the input shaft S1, the first outer hub H1 and the second inner hub H2 are arranged around the bearing at the connection, which can realize the transition connection between the input shaft S1 and the power take-off shaft S4, further ensure the coaxiality of the shaft rotation, and reduce the power loss caused by shaking during the rotation of the shaft.

[0064] The second inner hub H2 surrounds the connecting bearing of the input shaft S1 and the power take-off shaft S4 to reduce the leakage of lubricating oil. The second inner hub H2 can reduce the loss of lubricating oil of the bearing at the connection between the input shaft S1 and the power take-off shaft S4, reduce the frequency of adding lubricating oil, reduce the maintenance cost, and at the same time ensure the smoothness of power transmission of the power take-off shaft S4.

[0065] The through coaxial arrangement of the power take-off shaft S4 and the output shaft S3 enables the clutch mechanism to be concentratedly arranged at the shaft connection. Since the power take-off shaft S4 and the output shaft S3 are arranged in a through manner, the power take-off clutch system and the reversing clutch system can be concentratedly arranged in the space at the rotary connection of the input shaft S1, the output shaft S3 and the power take-off shaft S4, and the oil pressure established by the oil pump OP can be quickly switched between the third piston P3 and the second piston P2, that is, the corresponding rate of gear shifting between the forward gear and the reverse gear is accelerated, which helps to improve the efficiency of vehicle operation and vehicle driving.

[0066] The hydraulic control system controls the combination and separation of the clutch through the electromagnetic valve.

[0067] The clutch reversing system described above only needs to input an instruction to the oil pump OP to realize the function of automatically switching the driving direction of the vehicle during driving, and the automatic combination and separation of the power take-off mechanism, that is, the power reversing of the transmission system and the automatic power take-off of the electric control can be realized through a simple instruction. Not only does it realize automatic control to improve work efficiency and reduce labor intensity, but also through the optimized structural design, the structure of the entire transmission system is compact, and the system cost is reduced.

[0068] Embodiment two:

[0069] The power reversing mechanism realizes the power transmission between the intermediate shaft S2 and the output shaft S3 through a gear transmission system.

[0070] The gear transmission system includes: a first gear installed on the output shaft S3; a second gear installed on the intermediate shaft S2 through the seventh bearing B7; and an idler gear for transmission connection between the first gear and the first gear to realize the same direction rotation of the output shaft S3 and the intermediate shaft S2.

[0071] After adopting the gear transmission, the power transmission loss from the intermediate shaft S2 to the output shaft S3 is reduced, the overall power utilization rate of the agricultural machine is improved, especially in long-time high-load operation, the fuel or electric energy consumption can be reduced, and the economy is improved; the gear transmission scheme is conducive to reducing the noise pollution of the operating environment, improving the work experience of the agricultural machine operator; at the same time, the interference of vibration to other precision components is reduced, and the equipment failure rate is reduced.

[0072] Embodiment three:

[0073] On the basis of the embodiment 1 of the present application, the fourth sprocket W4 comprises a wheel body 20, the wheel body 20 is provided with a shaft hole 21 for assembling with the output shaft S3, the wheel body 20 is further provided with a mounting hole 22 arranged around the shaft hole 21, and an elastically deformable auxiliary element 3 is inserted into the mounting hole 22. The auxiliary element 3 comprises a sleeve body 30 matched with the mounting hole 22, the sleeve body 30 is an elastic column and is provided with a hollow slot 31 along the axis, and a cylindrical pin 32 is installed in the hollow slot 31. It is to be noted that the cylindrical pin 32 can extrude the sleeve body 30 under the action of inertia, and the material of the cylindrical pin 32 comprises but is not limited to metal. The mounting hole 22 comprises two concentrically arranged first arc walls 221, the first arc walls 221 are radially arranged on opposite sides of the auxiliary element 3, the first arc walls 221 have the same radius as the sleeve body 30, the mounting hole 22 further comprises two second arc walls 222, the second arc walls 222 are arranged between the two first arc walls 221 and are oppositely arranged, the centers of the two second arc walls 222 are respectively located on the two sides of the centers of the first arc walls 221, and the arc diameter of the second arc walls 222 is smaller than the outer diameter of the sleeve body 30. The cylindrical pin 32 passes through the hollow slot 31 and is provided with a limiting portion 33 at the end, and the limiting portion 33 is matched with the end face of the wheel body 20. Under the working 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, so as to realize the power output in the reverse gear, at this time, the fourth sprocket W4 rotates synchronously with the output shaft S3, and there is mechanical interference in the process that the third sprocket W3 transmits power to the fourth sprocket W4 through the second chain CH2, the mechanical interference can be buffered through the deformation of the sleeve body, which is conducive to improving the stability of power transmission in the chain drive system in the case of sudden acceleration or braking; when it is needed to quickly switch between the forward gear and the reverse gear, and the power output needs to be urgently interrupted, the fourth sprocket W4 and the output shaft S3 synchronously terminate the current rotation, the cylindrical pin 32 in the first arc wall 22 keeps the original motion state due to its inertia and extrudes the sleeve body 30, so that the sleeve body 30 is deformed to one side of the second arc wall 222, further eliminating the vibration interference and improving the stability and centring of each sprocket and chain in the chain drive system; at the same time, since the sleeve body 30 is matched in the two first arc walls 221, i.e. the sleeve body 30 and the second arc walls 222 on the two sides form a spacing space respectively, when the cylindrical pin 32 extrudes the sleeve body 30 to deform, the sleeve body 30 and the spacing space on the extrusion side release airflow, which can blow air to the fourth outer hub H4 on one side, so as to realize cooling of the fourth outer hub H4, thereby indirectly realizing heat dissipation of the brake pad set on the inner side of the fourth outer hub H4, i.e. automatically realizing cooling and heat dissipation of the brake pad set during the braking process and the power shifting process, on the one hand, improving the braking effect of the brake pad set, on the other hand, reducing the possibility of damage caused by excessive wear of the brake pad set due to high temperature, prolonging the service life of the brake pad set and improving the braking safety.Since the second arc-shaped wall 222 is oppositely arranged, no matter the reverse gear braking or the forward gear braking, the outer sleeve body can be deformed and extruded in the interval space on the corresponding side to realize exhaust heat dissipation, that is, the braking efficiency of the reverse gear braking and the braking efficiency in the forward gear braking can be improved to improve the working efficiency of the vehicle.

[0074] It will be apparent to those skilled in the art that the application is not limited to the details of the above-exemplified embodiments and that the application can be implemented in other particular forms without departing from the spirit or essential characteristics of the application. The embodiments should therefore be considered in all respects as illustrative and not restrictive, the scope of the application being indicated by the appended claims rather than by the above description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein. No reference signs in the claims should be considered as limiting the scope of the claims.

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); A hydraulic control system is used to drive the power reversing mechanism and the electronically controlled power take-off mechanism. 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). 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). The power take-off clutch includes: a first outer hub (H1) connected to the input shaft (S1); A second inner hub (H2) is connected to the power take-off shaft (S4) and is located on the inner side of the first outer hub (H1); a 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); 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; a first return spring group (SP1) is used to push the first piston (P1) back to its original position, so that the power take-off friction plate group is disengaged, thereby cutting off the power of the power take-off shaft (S4). 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.

2. 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.

3. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 2, 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.

4. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 3, 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).

5. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 2, 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).

6. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 5, 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.

7. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 6, 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).

8. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 5, 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).

9. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 8, 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).

10. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 7, 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).

11. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 10, 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).

12. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, 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).

13. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 1, 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.

14. 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.

15. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 5, 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.

16. The power reversing transmission mechanism for agricultural machinery with automatic power take-off switching according to claim 15, 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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