Agricultural universal chassis four-wheel hydraulic drive system

Abstract

The application discloses a general chassis four-wheel hydraulic driving system for agricultural use, and relates to the field of agricultural machines.The general chassis for agricultural use comprises four wheels, a control device, a hydraulic oil tank, two first power sources and four-wheel hydraulic walking systems.Each of the four-wheel hydraulic walking systems comprises a first variable pump, an oil supplementing pump, a filter, two overflow devices, a hydraulic control reversing oil valve, a back pressure valve and a bidirectional variable electromagnetic reversing control valve.Both ends of each of the first power sources are respectively connected with the first variable pump of one of the four-wheel hydraulic walking systems.Each variable motor is connected with the inner circumferential surface of the hub of one wheel.Between the two four-wheel hydraulic walking systems connected with the same first power source, a balance electromagnetic valve is arranged.The general chassis four-wheel hydraulic driving system for agricultural use can individually control the rotation of the four wheels of each general chassis for agricultural use according to the working requirements, and has the advantages of simple structure and low energy consumption.

Description

Technical Field

[0001] This invention relates to the field of agricultural machinery, and more specifically to a four-wheel hydraulic drive system for agricultural general-purpose chassis. Background Technology

[0002] With the development of technology, agricultural machinery has become an important piece of equipment in agricultural production, widely used in all aspects of agricultural production, such as sowing, spraying, irrigation, and harvesting. Currently, the commonly used agricultural general-purpose chassis employs traditional mechanical transmission systems in conjunction with manned operation to achieve field movement. Improvements for unmanned farms mainly focus on using electronically controlled steering wheels and electronic clutches. However, existing agricultural general-purpose chassis have the following drawbacks in controlling the rotation of each wheel: they require multi-stage gear transmission and shifting mechanisms, resulting in a complex and cumbersome transmission system with a fixed and singular layout, making it impossible to achieve continuously variable transmission, hindering automated and intelligent control, and making remote operation difficult. Summary of the Invention

[0003] The purpose of this invention is to provide a four-wheel hydraulic drive system for agricultural general-purpose chassis, which can individually control the rotation of the four wheels of each agricultural general-purpose chassis according to work needs, and has the advantages of simple structure and low energy consumption.

[0004] The technical solution adopted in this invention is as follows.

[0005] A general-purpose agricultural chassis four-wheel hydraulic drive system is characterized in that: the general-purpose agricultural chassis includes four wheels, a control device, a hydraulic oil tank, two primary power sources, and a four-wheel hydraulic walking system.

[0006] Each wheel's hydraulic travel system includes a first variable pump, a replenishing pump, a filter, two overflow devices, a hydraulically controlled directional valve, a back pressure valve, and a two-way variable electromagnetic directional control valve.

[0007] In the hydraulic travel system of each wheel, the first variable pump is equipped with a first variable vane and a first variable vane control mechanism. The two ends of the first variable pump are respectively connected to the two ends of the variable motor through the main drive pipe to form the main circuit of the variable motor. The hydraulic oil tank, the replenishing pump, and the filter are connected in sequence through pipelines. The filter is connected to two fifth connecting oil pipes through a fourth connecting oil pipe. The two fifth connecting oil pipes are respectively connected to a main drive pipe, and each fifth connecting oil pipe is equipped with an overflow device. The two main drive pipes are connected through pipelines, and the pipelines are equipped with hydraulic control directional valves. The hydraulic control directional valves are connected to a back pressure valve through pipelines. The first back pressure valve is connected to the hydraulic oil tank through pipelines. The pipeline between the replenishing pump and the filter is connected to the first overflow valve, and the first overflow valve is connected to the hydraulic oil tank through pipelines.

[0008] The overflow device includes a manual valve, a second check valve, and a second overflow valve connected in parallel. The oil inlet of each second check valve is connected to the filter through a pipeline, and the oil outlet of each second check valve is connected to the main drive pipe through a pipeline.

[0009] The filter is connected to a bidirectional variable solenoid directional control valve via a pipeline; the bidirectional variable solenoid directional control valve is connected to the first variable vane control mechanism; and the bidirectional variable solenoid directional control valve is connected to the hydraulic oil tank.

[0010] Each of the two ends of the first power source is individually connected to the first variable pump of the hydraulic walking system of a wheel.

[0011] Each variable displacement motor is connected to the inner circumferential surface of the hub of a wheel; a balancing solenoid valve is provided between the hydraulic walking systems of the two wheels connected to the same first power source; the two inlet and outlet ports of the liquid outlet end of each bidirectional variable solenoid directional control valve in each wheel hydraulic walking system are connected to the two ends of the balancing solenoid valve respectively; a differential pressure sensor is provided on the balancing solenoid valve; the differential pressure sensor, the balancing solenoid valve, and each bidirectional variable solenoid directional control valve are connected to the control device.

[0012] The beneficial effects of this invention are as follows: An oil replenishment pump and a filter are provided. One oil path, via the oil replenishment pump, filter, and overflow device, enters the lower pressure of the two main drive pipes to replenish the control oil. Another oil path, via the oil replenishment pump, filter, and bidirectional variable electromagnetic reversing control valve, enters the first variable vane control mechanism. The control system controls the bidirectional variable electromagnetic reversing control valve to control the flow direction of the liquid entering the first variable vane control mechanism, thereby controlling the operation of the first variable vane of the first variable pump. The hydraulic system flow rate can be adjusted according to actual working conditions to control the flow direction of the oil entering the variable motor, thus controlling the rotation direction of the variable motor. All four variable motors can be individually controlled by the bidirectional variable electromagnetic reversing control valve control device. A balancing solenoid valve is provided between the two wheel hydraulic travel systems connected to the same first power source. The balancing solenoid valve is equipped with a differential pressure sensor to balance the pressure difference between the two wheel hydraulic travel systems, thereby synchronizing the movement of the wheels connected to the two wheel hydraulic travel systems. The hydraulically controlled directional valve is connected to the back pressure valve via pipeline. It balances excessive pressure differences between the two main drive pipes during vehicle movement, protecting the variable displacement motor, and directs high-temperature hydraulic fluid (when the pressure difference exceeds the back pressure valve's set pressure) into the hydraulic tank. The overflow device includes a parallel manual valve, a second check valve, and a second overflow valve, providing a stable flow to the two main drive pipes. This prevents significant fluctuations in system flow caused by hydraulic oil continuously flowing from the back pressure valve into the hydraulic tank during intermittent braking, thus ensuring stable wheel rotation. The agricultural general-purpose chassis four-wheel hydraulic drive system is a unified system. It can independently control the variable displacement motor according to working conditions and maintain system flow and pressure balance. It features low energy consumption, stable power, and is suitable for use on agricultural general-purpose chassis, adapting to slopes, muddy terrain, and other challenging conditions.

[0013] As a preferred technical solution, the hydraulic oil tank is connected to several coolers.

[0014] As a preferred technical solution, a first check valve is provided on the pipeline between the filter and the bidirectional variable electromagnetic reversing control valve.

[0015] As a preferred technical solution, the hydraulic control directional valve is a three-position three-way hydraulic control valve.

[0016] As a preferred technical solution, the inlets of the two hydraulically controlled directional valves are respectively connected to a main drive pipe through a first connecting oil pipe; the outlets of the hydraulically controlled directional valves are connected to a first back pressure valve through a second connecting oil pipe; and the two spring hydraulic control ends of the hydraulically controlled directional valves are respectively connected to a main drive pipe through a third connecting oil pipe.

[0017] When the pressure of one main drive pipe is greater than the pressure of the other main drive pipe, the third connecting oil pipe connected to the main drive pipe with the higher pressure is connected to the outlet of the hydraulic directional valve. When the pressures of the two main drive pipes are the same, neither of the two third connecting oil pipes is connected to the outlet of the hydraulic directional valve.

[0018] As a preferred technical solution, the two ends of the first check valve are connected to the bypass valve through pipelines.

[0019] This technical solution can provide stable hydraulic pressure to the bidirectional variable electromagnetic directional control valve.

[0020] As a preferred technical solution, the variable motor, hydraulic directional valve, and back pressure valve of each wheel hydraulic travel system are installed on the first valve block; the first variable pump, replenishing pump, and first relief valve of each wheel hydraulic travel system are installed on the second valve block; the filter of each wheel hydraulic travel system is installed on the third valve block; and the first check valve, bypass valve, and bidirectional variable electromagnetic directional control valve of each wheel hydraulic travel system are installed on the fourth valve block.

[0021] As a preferred technical solution, the portion between the first valve block and the second valve block of the main drive pipe is a flexible hose.

[0022] As a preferred technical solution, the bidirectional variable electromagnetic directional control valve is a three-position five-way solenoid valve. The filter is connected to the oil inlet of the bidirectional variable electromagnetic directional control valve through a pipeline. The first working oil port and the second working oil port of the bidirectional variable electromagnetic directional control valve are respectively connected to both ends of the first variable vane control mechanism through pipelines. The first return oil port and the second return oil port of the bidirectional variable electromagnetic directional control valve are respectively connected to the hydraulic oil tank through pipelines.

[0023] This technical solution allows for adjustment of the flow direction of the oil entering the first variable blade control mechanism.

[0024] As a preferred technical solution, the agricultural universal chassis four-wheel hydraulic drive system further includes a hydraulic steering system. The hydraulic steering system includes a second power source, a load-sensitive control module, several steering control modules, a long supply pipe, a long return pipe, a long control oil pipe, and several wheel steering hydraulic cylinders. Each wheel's travel drive variable motor is mounted on a bracket, and the top of each bracket is connected to a vertically arranged rotating shaft. Each rotating shaft is connected to the agricultural universal chassis. Each rotating shaft is connected to several wheel steering hydraulic cylinders through rotating lugs.

[0025] The load-sensitive control module includes a second variable pump, a second variable vane electromagnetic control valve assembly, a first outlet pipe, a first inlet pipe, and a first return pipe; the second variable pump is connected to a second power source, the hydraulic oil tank is connected to the inlet of the second variable pump through the first inlet pipe, the outlet of the second variable pump is connected to the first return pipe through the first outlet pipe, and the first return pipe is connected to the hydraulic oil tank.

[0026] The first outlet pipe is connected to the long supply pipe; the end of the long return pipe furthest from the second variable pump is connected to the long control oil pipe, and the end of the long return pipe closest to the second variable pump is connected to the first return pipe.

[0027] The end of the long control oil pipe near the second variable pump is connected to the oil inlet of the second variable vane electromagnetic control valve assembly of the second variable pump. The oil inlet of the second variable vane electromagnetic control valve assembly is equipped with a pressure sensor. The oil outlet of the second variable vane electromagnetic control valve assembly is connected to the first return pipe through the second outlet pipe. The pressure sensor is connected to the second variable vane electromagnetic control valve assembly and the control device of the second variable pump through wiring.

[0028] The second variable vane electromagnetic control valve assembly is connected to the second variable vane of the second variable pump; a plug is provided at the end of the long supply pipe away from the second variable pump.

[0029] Each steering control module includes a three-position five-way multi-control solenoid valve, a first pressure compensation valve, and a shuttle valve. The oil inlet of the three-position five-way multi-control solenoid valve is connected to the long supply pipe through the second inlet pipe. The oil outlets of the two three-position five-way multi-control solenoid valves are respectively connected to the third outlet pipe through a sixth outlet pipe, and the third outlet pipe is connected to the long return pipe. Each sixth outlet pipe is connected to the shuttle valve through a bypass pipe. The two ends of each wheel steering hydraulic cylinder are respectively connected to the working oil port of the two three-position five-way multi-control solenoid valves through a fourth outlet pipe.

[0030] Each three-position five-way multi-channel control solenoid valve, the second variable vane solenoid control valve assembly, and the pressure sensor are respectively connected to the control device; the first pressure compensation valve is located on the second inlet pipe; the first pressure compensation valve is connected to the shuttle valve through the fifth outlet pipe; each shuttle valve is located on the long control oil pipe.

[0031] The first outlet pipe is connected to the first return pipe via the second return pipe, and the second return pipe is equipped with a second pressure compensation valve; the second pressure compensation valve is connected to the long control oil pipe via the third return pipe; the first outlet pipe is connected to the long return pipe via the fourth return pipe, and the fourth return pipe is equipped with a third relief valve; the fourth return pipe is connected to the third return pipe; the first outlet pipe and the long return pipe are connected via a pressure reducing valve and a fourth relief valve.

[0032] Each wheel steering hydraulic cylinder connected to a wheel is connected to a three-position five-way multi-control solenoid valve at both ends. The solenoid valves control the flow of oil into and out of each cylinder, enabling independent steering control for each wheel. Each hydraulic control module is equipped with a shuttle valve and a first pressure compensation valve to compensate for pressure. Each shuttle valve is located on a long control oil pipe, which draws oil from each valve and is connected to a pressure sensor. The pressure sensor measures the pressure in the control oil pipe and provides pressure information to the control device. Based on this pressure information, the control device controls the second variable vane solenoid valve assembly to operate, controlling the flow and pressure of the second variable pump. The higher the real-time pressure measured by the pressure sensor, the greater the flow and pressure the second variable pump needs to provide. A second pressure compensation valve, a third relief valve, and a fourth relief valve are provided to balance the flow and pressure of the inlet, return, and control oil circuits, preventing excessive flow differences that could lead to system instability. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the structure of the agricultural universal chassis four-wheel hydraulic drive system of the present invention.

[0034] Figure 2 yes Figure 1 A magnified view of part A.

[0035] Figure 3 yes Figure 2 A magnified view of part C.

[0036] Figure 4 yes Figure 2 A magnified view of part D.

[0037] Figure 5 yes Figure 1 A magnified view of part B.

[0038] Figure 6 yes Figure 5 A magnified view of part E.

[0039] Figure 7 This is a structural diagram of a general-purpose agricultural chassis.

[0040] Figure 8 yes Figure 7 A magnified view of part F.

[0041] Figure 9 yes Figure 7 A magnified view of part G.

[0042] Figure 10 This is a schematic diagram of the hydraulic steering system of the four-wheel hydraulic drive system for agricultural general-purpose chassis of the present invention.

[0043] Figure 11 yes Figure 10 A magnified view of part H.

[0044] Figure 12 yes Figure 10 A magnified view of part I.

[0045] Figure 13 yes Figure 10 A magnified view of part J.

[0046] Among them: hydraulic oil tank-1;

[0047] First Power Source-2;

[0048] First variable pump-3; First variable blade-31; First variable blade control mechanism-32;

[0049] Variable displacement motor-4; make-up oil pump-5;

[0050] Filter-6; Fourth connecting oil pipe-61; Fifth connecting oil pipe-62;

[0051] Hydraulic directional valve - 7; Hydraulic directional valve inlet - 71; First connecting oil pipe - 72; Hydraulic directional valve outlet - 73; Second connecting oil pipe - 74; Third connecting oil pipe - 75;

[0052] Back pressure valve-8;

[0053] Two-way variable electromagnetic reversing control valve -9; First working port of the two-way variable electromagnetic reversing control valve -91; Second working port of the two-way variable electromagnetic reversing control valve -92; Inlet port of the two-way variable electromagnetic reversing control valve -93; First return port of the two-way variable electromagnetic reversing control valve -94; Second return port of the two-way variable electromagnetic reversing control valve -95.

[0054] Main drive transistor -10;

[0055] Overflow device-11; Manual valve-111; Second check valve-112; Second overflow valve-113;

[0056] First relief valve-12; Balance solenoid valve-13; Differential pressure sensor-131;

[0057] Cooler-14;

[0058] First check valve-15; Bypass valve-16;

[0059] Fourth valve block -17; First valve block -18; Second valve block -19; Third valve block -20;

[0060] Second Power Source-21;

[0061] Second variable pump - 221; Second variable vane electromagnetic control valve assembly - 222; First inlet pipe - 223; First outlet pipe - 224; First return pipe - 225; Pressure sensor - 226; Second variable vane - 227; Second outlet pipe - 228;

[0062] Three-position five-way multi-way control solenoid valve - 231; Oil inlet of three-position five-way multi-way control solenoid valve - 2311; Oil outlet of three-position five-way multi-way control solenoid valve - 2312; Working oil port of three-position five-way multi-way control solenoid valve - 2313;

[0063] First pressure compensation valve - 232; shuttle valve - 233; second inlet pipe - 234; sixth outlet pipe - 235; fifth outlet pipe - 236; third outlet pipe - 237; bypass pipe - 238; fourth outlet pipe - 239;

[0064] Long supply pipe-24; plug-in-241; second return pipe-242; second pressure compensation valve-243; third return pipe-244; fourth return pipe-245; third relief valve-246; pressure reducing valve-247; fourth relief valve-248;

[0065] Long return tube -25;

[0066] Long control tubing -26;

[0067] Wheel steering hydraulic cylinder-27;

[0068] Bracket-28;

[0069] Shaft-29;

[0070] Agricultural general purpose chassis-30;

[0071] Wheel-301;

[0072] Rotary ear - 302; Wheel hub - 33. Detailed Implementation

[0073] The present invention will now be further described in conjunction with the accompanying drawings and embodiments.

[0074] Example 1. As... Figure 1-6 As shown, an agricultural general-purpose chassis four-wheel hydraulic drive system is characterized in that: the agricultural general-purpose chassis includes four wheels 301, a control device, a hydraulic oil tank 1, two first power sources 2, and a four-wheel hydraulic walking system.

[0075] The hydraulic travel system of each wheel includes a first variable pump 3, a replenishing pump 5, a filter 6, two overflow devices 11, a hydraulic control directional valve 7, a back pressure valve 8, and a two-way variable electromagnetic directional control valve 9.

[0076] In the hydraulic travel system of each wheel, the first variable pump 3 is equipped with a first variable vane 31 and a first variable vane control mechanism 32. The two ends of the first variable pump 3 are respectively connected to the two ends of the variable motor 4 through the main drive pipe 10 to form the main circuit of the variable motor 4. The hydraulic oil tank 1, the replenishing pump 5, and the filter 6 are connected in sequence through pipelines. The filter 6 is connected to two fifth connecting oil pipes 62 through the fourth connecting oil pipe 61. The two fifth connecting oil pipes 62 are respectively connected to a main drive pipe 10, and each fifth connecting oil pipe 62 is equipped with an overflow device 11.

[0077] Two main drive pipes 10 are connected by a pipeline and a hydraulic control directional valve 7 is provided on the pipeline. The hydraulic control directional valve 7 is connected to a back pressure valve 8 through a pipeline. The first back pressure valve 8 is connected to the hydraulic oil tank 1 through a pipeline. The pipeline between the replenishment pump 5 and the filter 6 is connected to the first relief valve 12. The first relief valve 12 is connected to the hydraulic oil tank 1 through a pipeline.

[0078] The overflow device 11 includes a manual valve 111, a second check valve 112, and a second overflow valve 113 connected in parallel. The oil inlet of each second check valve 112 is connected to the filter 6 through a pipeline, and the oil outlet of each second check valve 112 is connected to the main drive pipe 10 through a pipeline.

[0079] The filter 6 is connected to the bidirectional variable electromagnetic reversing control valve 9 via a pipeline; the bidirectional variable electromagnetic reversing control valve 9 is connected to the first variable vane control mechanism 32; and the bidirectional variable electromagnetic reversing control valve 9 is connected to the hydraulic oil tank 1.

[0080] Each of the two ends of the first power source 2 is individually connected to the first variable pump 3 of the hydraulic walking system of a wheel.

[0081] Each variable motor 4 is connected to the inner circumferential surface of the hub 32 of a wheel 301; a balance solenoid valve 13 is provided between the two wheel hydraulic walking systems connected to the same first power source 2; the two inlet and outlet ports of each bidirectional variable solenoid directional control valve 9 in each wheel hydraulic walking system are connected to the two ends of the balance solenoid valve 13 respectively; a differential pressure sensor 131 is provided on the balance solenoid valve 13; the differential pressure sensor 131, the balance solenoid valve 13, and each bidirectional variable solenoid directional control valve 9 are connected to the control device.

[0082] The hydraulic oil tank 1 is connected to the two coolers 14.

[0083] A first check valve 15 is installed on the pipeline between filter 6 and bidirectional variable electromagnetic reversing control valve 9.

[0084] The hydraulic control directional valve 7 is a three-position three-way hydraulic control valve.

[0085] The inlet 71 of the two hydraulically controlled directional valves 7 are respectively connected to a main drive pipe 10 through a first connecting oil pipe 72; the outlet 73 of the hydraulically controlled directional valve is connected to a first back pressure valve 8 through a second connecting oil pipe 74; the two spring hydraulic control ends of the hydraulically controlled directional valves 7 are respectively connected to a main drive pipe 10 through a third connecting oil pipe 75.

[0086] The flow direction of the hydraulic oil in the main circuit is controlled by the first variable pump 3. The control device is a PLC. When the pressure of one main drive pipe 10 is greater than the pressure of the other main drive pipe 10, the third connecting oil pipe 75 connected to the main drive pipe 10 with the higher pressure is connected to the outlet 73 of the hydraulic control directional valve 7. When the pressures of the two main drive pipes 10 are the same, neither of the two third connecting oil pipes 75 is connected to the outlet 73 of the hydraulic control directional valve 7.

[0087] As a preferred technical solution, the two ends of the first one-way valve 15 are connected to the bypass valve 16 via pipelines. This technical solution provides stable hydraulic pressure to the bidirectional variable electromagnetic directional control valve 9.

[0088] The variable displacement motor 4, hydraulic directional valve 7, and back pressure valve 8 of each wheel hydraulic travel system are installed on the first valve block 18; the first variable displacement pump 3, replenishing pump 5, and first overflow valve 12 of each wheel hydraulic travel system are installed on the second valve block 19; the filter 6 of each wheel hydraulic travel system is installed on the third valve block 20; and the first check valve 15, bypass valve 16, and bidirectional variable electromagnetic directional control valve 9 of each wheel hydraulic travel system are installed on the fourth valve block 17.

[0089] The portion between the first valve block 18 and the second valve block 19 of the main drive pipe 10 is a flexible hose. The two-wheel hydraulic walking systems connected to the same first power source 2 are distributed in a mirror image.

[0090] The bidirectional variable electromagnetic directional control valve 9 is a three-position five-way solenoid valve. The filter 6 is connected to the inlet 93 of the bidirectional variable electromagnetic directional control valve via a pipeline. The first working port 91 and the second working port 92 of the bidirectional variable electromagnetic directional control valve are respectively connected to both ends of the first variable vane control mechanism 32 via pipelines. The first return port 94 and the second return port 95 of the bidirectional variable electromagnetic directional control valve are respectively connected to the hydraulic oil tank 1 via pipelines. In the hydraulic travel system of each wheel, when the left position of the bidirectional variable electromagnetic directional control valve 9 is closed, the hydraulic oil enters the left end of the first variable vane control mechanism 32 from the first working port 91, and flows into the hydraulic oil tank from the right end of the first variable vane control mechanism 32 via the second return port 95. When the right position of the bidirectional variable electromagnetic directional control valve 9 is closed, the hydraulic oil enters the left end of the first variable vane control mechanism 32 from the second working port 92, and flows into the hydraulic oil tank from the right end of the first variable vane control mechanism 32 via the first return port 94. When the bidirectional variable electromagnetic reversing control valve 9 is in the neutral position, the hydraulic oil in the first variable vane control mechanism 32 does not flow.

[0091] The system includes a replenishing pump 5 and a filter 6. One path of hydraulic fluid flows through the replenishing pump 5, filter 6, and overflow device 11 into the main drive pipe 10 with the lower pressure, replenishing the control fluid. Another path of hydraulic fluid flows through the replenishing pump 5, filter 6, and bidirectional variable electromagnetic reversing control valve 9 into the first variable vane control mechanism 32. The control system controls the bidirectional variable electromagnetic reversing control valve 9 to control the flow direction of the fluid entering the first variable vane control mechanism 32, thereby controlling the operation of the first variable vane of the first variable pump 3. The hydraulic system flow rate can be adjusted according to actual working conditions to control the flow direction of the hydraulic fluid entering the variable motor 4, thus controlling the rotation direction of the variable motor 4. All four variable motors 4 can be individually controlled by the control device via the bidirectional variable electromagnetic reversing control valve 9. A balancing solenoid valve 13 is provided between the two wheel hydraulic walking systems connected to the same first power source 2. The balancing solenoid valve 13 is equipped with a differential pressure sensor 131 to balance the pressure difference between the two wheel hydraulic walking systems, thereby synchronizing the movement of the wheels connected to the two wheel hydraulic walking systems. The hydraulic directional valve 7 is connected to the back pressure valve 8 via a pipeline. It balances the excessive pressure difference between the two main drive pipes 10 during vehicle movement, such as during emergency braking, protecting the variable displacement motor 4. It also delivers high-temperature hydraulic oil, which operates when the pressure difference exceeds the pressure set by the back pressure valve, into the hydraulic oil tank 1. The overflow device 11 includes a parallel manual valve 111, a second check valve 112, and a second overflow valve 113. It provides a stable flow to the two main drive pipes 10, preventing large fluctuations in system flow caused by hydraulic oil continuously flowing from the back pressure valve 8 into the hydraulic oil tank 1 during intermittent braking, thus preventing unstable wheel rotation. The agricultural general-purpose chassis four-wheel hydraulic drive system is an integrated system that can independently control the variable displacement motor 4 according to working conditions and maintain system flow and pressure balance, resulting in low energy consumption.

[0092] Example 2. (As shown) Figure 7-13 As shown, the difference between this embodiment and Embodiment 1 is that the agricultural universal chassis four-wheel hydraulic drive system also includes a hydraulic steering system. The hydraulic steering system includes a second power source 21, a load-sensitive control module, four steering control modules, a long supply pipe 24, a long return pipe 25, a long control oil pipe 26, and several wheel steering hydraulic cylinders 27. Each wheel travel drive variable motor 4 is mounted on a bracket 28, and the top of each bracket 28 is connected to a vertically arranged rotating shaft 29. Each rotating shaft 29 is connected to the agricultural universal chassis 30. Each rotating shaft 29 is connected to a wheel steering hydraulic cylinder 27 through a rotating lug 302.

[0093] The load-sensitive control module includes a second variable pump 221, a second variable vane electromagnetic control valve assembly 222, a first outlet pipe 224, a first inlet pipe 223, and a first return pipe 225. The second variable pump 221 is connected to the second power source 21. The hydraulic oil tank 1 is connected to the inlet of the second variable pump 221 through the first inlet pipe 223. The outlet of the second variable pump 221 is connected to the first return pipe 225 through the first outlet pipe 224. The first return pipe 225 is connected to the hydraulic oil tank 1.

[0094] The first outlet pipe 224 is connected to the long supply pipe 24; the end of the long return pipe 25 furthest from the second variable pump 221 is connected to the long control oil pipe 26, and the end of the long return pipe 25 closest to the second variable pump 221 is connected to the first return pipe 225.

[0095] The end of the long control oil pipe 26 near the second variable pump 221 is connected to the oil inlet 2221 of the second variable vane electromagnetic control valve assembly of the second variable pump 221. The oil inlet of the second variable vane electromagnetic control valve assembly 222 is equipped with a pressure sensor 226. The oil outlet 2222 of the second variable vane electromagnetic control valve assembly is connected to the first return pipe 225 through the second outlet pipe 228. The pressure sensor 226 is connected to the second variable vane electromagnetic control valve assembly 222 of the second variable pump 221 and the control device through wiring.

[0096] The second variable blade electromagnetic control valve assembly 222 is connected to the second variable blade 227 of the second variable pump 221; a plug 241 is provided at the end of the long supply pipe 24 away from the second variable pump 221.

[0097] Each steering control module includes a three-position five-way multi-control solenoid valve 231, a first pressure compensation valve 232, and a shuttle valve 233. The oil inlet 2311 of the three-position five-way multi-control solenoid valve is connected to the long supply pipe 24 through the second inlet pipe 234. The oil outlets 2312 of the two three-position five-way multi-control solenoid valves are respectively connected to the third outlet pipe 237 through a sixth outlet pipe 235. The third outlet pipe 237 is connected to the long return pipe 25. Each sixth outlet pipe 235 is respectively connected to the shuttle valve 233 through a bypass pipe 238. The two ends of each wheel steering hydraulic cylinder 27 are respectively connected to the working oil ports 2313 of the two three-position five-way multi-control solenoid valves through a fourth outlet pipe 239.

[0098] Each three-position five-way multi-channel control solenoid valve 231, the second variable vane solenoid control valve assembly 222, and the pressure sensor 226 are respectively connected to the control device; the first pressure compensation valve 232 is located on the second inlet pipe 234; the first pressure compensation valve 232 is connected to the shuttle valve 233 through the fifth outlet pipe 236; each shuttle valve 233 is located on the long control oil pipe 26.

[0099] The first outlet pipe 224 is connected to the first return pipe 225 via the second return pipe 242. The second return pipe 242 is equipped with a second pressure compensation valve 243. The second pressure compensation valve 243 is connected to the long control oil pipe 26 via the third return pipe 244. The first outlet pipe 224 is connected to the long return pipe 25 via the fourth return pipe 245. The fourth return pipe 245 is equipped with a third overflow valve 246. The fourth return pipe 245 is connected to the third return pipe 244. The first outlet pipe 224 and the long return pipe 25 are connected via a pressure reducing valve 247 and a fourth overflow valve 248.

[0100] Each wheel steering hydraulic cylinder 27 connected to a wheel is connected at both ends to a three-position five-way multi-control solenoid valve 231. The three-position five-way multi-control solenoid valve 231 controls the oil flow into or out of each wheel steering hydraulic cylinder 27, achieving independent steering control for each wheel. Each hydraulic control module is equipped with a shuttle valve 233 and a first pressure compensation valve 232 to compensate for pressure. Each shuttle valve 233 is mounted on a long control oil pipe 26, which draws oil from each shuttle valve 233. The long control oil pipe 26 is connected to a pressure sensor 226, which measures the pressure in the long control oil pipe 26 and provides pressure information to the control device. Based on the provided pressure information, the control device controls the operation of the second variable vane electromagnetic control valve assembly 222, controlling the flow and pressure of the second variable pump 221. The higher the real-time pressure measured by the pressure sensor 226, the greater the flow and pressure required by the second variable pump 221. The system is equipped with a second pressure compensation valve 243, a third relief valve 246, and a fourth relief valve 248 to achieve flow and pressure balance in the oil inlet, oil return, and control oil circuits, preventing the system from operating unstablely due to excessive flow differences.

[0101] Example 3. The difference between this example and Example 2 is that the eight-hydraulic steering system includes eight steering control modules; each pivot is connected to two wheel steering hydraulic cylinders 27 via a pivot lug 302.

[0102] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. An agricultural utility chassis four wheel hydraulic drive system characterized by: The utility model provides a kind of agricultural general chassis, including four wheels, control device, hydraulic oil tank (1), two first power sources (2), four wheel hydraulic walking system; Each wheel hydraulic walking system includes first variable pump (3), oil supplement pump (5), filter (6), two overflow devices (11), hydraulic control reversing oil valve (7), back pressure valve (8), two-way variable electromagnetic reversing control valve (9); In each wheel hydraulic walking system, first variable pump (3) is equipped with first variable vane (31) and first variable vane control mechanism (32), the two ends of first variable pump (3) are connected with the two ends of wheel walking drive variable motor (4) through main drive pipe (10) respectively, to form wheel walking drive variable motor (4) main circuit;Hydraulic oil tank (1), oil supplement pump (5) and filter (6) are connected in sequence through pipeline, filter (6) is connected with two fifth communication oil pipes (62) through fourth communication oil pipe (61), two fifth communication oil pipes (62) are connected with a main drive pipe (10) respectively, and each fifth communication oil pipe (62) is equipped with overflow device (11);Two main drive pipes (10) are connected through pipeline, and the pipeline is equipped with hydraulic control reversing oil valve (7), hydraulic control reversing oil valve (7) is connected with back pressure valve (8) through pipeline, and first back pressure valve (8) is connected with hydraulic oil tank (1) through pipeline;The pipeline between oil supplement pump (5) and filter (6) is connected with first overflow valve (12), and first overflow valve (12) is connected with hydraulic oil tank (1) through pipeline; Overflow device (11) includes parallel hand valve (111), second check valve (112) and second overflow valve (113), the oil inlet of each second check valve (112) is connected with filter (6) through pipeline, and the oil outlet of each second check valve (112) is connected with main drive pipe (10) through pipeline; Filter (6) is connected with two-way variable electromagnetic reversing control valve (9) through pipeline;Two-way variable electromagnetic reversing control valve (9) is connected with first variable vane control mechanism (32);Two-way variable electromagnetic reversing control valve (9) is connected with hydraulic oil tank (1); The two ends of each first power source (2) are connected with the first variable pump (3) of a wheel hydraulic walking system respectively; Each wheel walking drive variable motor (4) is connected with the inner circumferential surface of the hub of a wheel respectively;Between two wheel hydraulic walking systems connected with the same first power source (2), balance electromagnetic valve (13) is equipped, the two inlet and outlet ports of the outlet end of each two-way variable electromagnetic reversing control valve (9) in each wheel hydraulic walking system are connected with the two pipelines connected with first variable vane control mechanism (32), and the two ends of balance electromagnetic valve (13) are connected with the two pipelines respectively, pressure difference sensor (131) is equipped on balance electromagnetic valve (13), pressure difference sensor (131), balance electromagnetic valve (13), each two-way variable electromagnetic reversing control valve (9) and control device are connected.

2. An agricultural utility chassis four wheel hydraulic drive system as claimed in claim 1 characterized by: Hydraulic oil tank (1) is connected with several coolers (14).

3. An agricultural utility vehicle four wheel hydraulic drive system as claimed in claim 1, characterized in that: First check valve (15) is equipped on the pipeline between filter (6) and two-way variable electromagnetic reversing control valve (9).

4. An agricultural utility chassis four wheel hydraulic drive system as claimed in claim 3 wherein: Hydraulic control reversing oil valve (7) is three-position three-way hydraulic control valve.

5. An agricultural utility chassis four wheel hydraulic drive system as claimed in claim 4, characterized by: The inlet (71) of the two-way hydraulic control reversing valve is connected with the main driving pipe (10) through a first connecting pipe (72); the outlet (73) of the two-way hydraulic control reversing valve is connected with the first back pressure valve (8) through a second connecting pipe (74); the two spring hydraulic control ends of the two-way hydraulic control reversing valve (7) are connected with the main driving pipe (10) through a third connecting pipe (75).

6. An agricultural utility chassis four wheel hydraulic drive system as claimed in claim 3, characterized by: The two ends of the first one-way valve (15) are connected with the bypass valve (16) through pipes.

7. An agricultural utility chassis four wheel hydraulic drive system as claimed in claim 6, characterized by: The wheel walking driving variable motor (4), the two-way hydraulic control reversing valve (7) and the back pressure valve (8) of each wheel hydraulic walking system are installed on the first valve block (18); the first variable pump (3), the oil supplement pump (5) and the first overflow valve (12) of each wheel hydraulic walking system are installed on the second valve block (19); the filter (6) of each wheel hydraulic walking system is installed on the third valve block (20); the first one-way valve (15), the bypass valve (16) and the two-way variable electromagnetic reversing control valve (9) of each wheel hydraulic walking system are installed on the fourth valve block (17).

8. An agricultural utility vehicle four wheel hydraulic drive system as claimed in claim 7, characterized by: The part between the first valve block (18) and the second valve block (19) of the main driving pipe (10) is a hose.

9. The four-wheel hydraulic driving system of the agricultural universal chassis according to claim 1, characterized in that: The two-way variable electromagnetic reversing control valve (9) is a three-position five-way electromagnetic valve; the filter (6) is connected with the oil inlet (93) of the two-way variable electromagnetic reversing control valve through a pipe; the first working oil port (91) of the two-way variable electromagnetic reversing control valve and the second working oil port (92) of the two-way variable electromagnetic reversing control valve are respectively connected with the two ends of the first variable vane control mechanism (32) through pipes; the first return oil port (94) of the two-way variable electromagnetic reversing control valve (9) and the second return oil port (95) of the two-way variable electromagnetic reversing control valve are respectively connected with the hydraulic oil tank (1) through pipes.

10. The four-wheel hydraulic driving system of the agricultural universal chassis according to claim 1, characterized in that: The four-wheel hydraulic driving system of the agricultural universal chassis further comprises a hydraulic steering system, which comprises a second power source (21), a load-sensitive control module, a plurality of steering control modules, a long oil supply pipe (24), a long return oil pipe (25), a long control oil pipe (26) and a plurality of wheel steering hydraulic cylinders (27); each wheel walking driving variable motor (4) is installed on a support (28); the top end of each support (28) is connected with a vertical shaft (29); each shaft (29) is connected with the agricultural universal chassis (30); each shaft (29) is connected with the plurality of wheel steering hydraulic cylinders (27) through a rotating ear (302). The load sensitive control module comprises a second variable pump (221), a second variable vane electromagnetic control valve assembly (222), a first liquid outlet pipe (224), a first liquid inlet pipe (223) and a first return pipe (225); the second variable pump (221) is connected with a second power source (21); a hydraulic oil tank (1) is connected with a liquid inlet of the second variable pump (221) through the first liquid inlet pipe (223); a liquid outlet of the second variable pump (221) is connected with the first return pipe (225) through the first liquid outlet pipe (224); and the first return pipe (225) is connected with the hydraulic oil tank (1); The first liquid outlet pipe (224) is connected with a long liquid supply pipe (24); a long return pipe (25) is connected with the long control oil pipe (26) at a position far away from the second variable pump (221); and the long return pipe (25) is connected with the first return pipe (225) at a position close to the second variable pump (221); The long control oil pipe (26) is connected with an oil inlet (2221) of the second variable vane electromagnetic control valve assembly of the second variable pump (221) at a position close to the second variable pump (221); and the oil inlet of the second variable vane electromagnetic control valve assembly (222) is provided with a pressure sensor (226); An oil outlet (2222) of the second variable vane electromagnetic control valve assembly is connected with the first return pipe (225) through a second liquid outlet pipe (228); the pressure sensor (226) is connected with the second variable vane electromagnetic control valve assembly (222) of the second variable pump (221) and a control device through lines respectively; The second variable vane electromagnetic control valve assembly (222) is connected with a second variable vane (227) of the second variable pump (221); and the long liquid supply pipe (24) is provided with a stopper (241) at a position far away from the second variable pump (221); Each steering control module comprises a three-position five-way multi-way control electromagnetic valve (231), a first pressure compensation valve (232) and a shuttle valve (233); an oil inlet (2311) of the three-position five-way multi-way control electromagnetic valve is connected with the long liquid supply pipe (24) through a second liquid inlet pipe (234); two oil outlets (2312) of the three-position five-way multi-way control electromagnetic valve are connected with a third liquid outlet pipe (237) through a sixth liquid outlet pipe (235) and a seventh liquid outlet pipe (235) respectively; the third liquid outlet pipe (237) is connected with the long return pipe (25); each sixth liquid outlet pipe (235) is connected with the shuttle valve (233) through a bypass pipe (238); and two ends of each wheel steering hydraulic cylinder (27) are connected with working oil inlets (2313) of the two three-position five-way multi-way control electromagnetic valves through a fourth liquid outlet pipe (239) respectively; Each three-position five-way multi-way control electromagnetic valve (231), the second variable vane electromagnetic control valve assembly (222) and the pressure sensor (226) are connected with the control device respectively; the first pressure compensation valve (232) is located on the second liquid inlet pipe (234); the first pressure compensation valve (232) is connected with the shuttle valve (233) through a fifth liquid outlet pipe (236); and each shuttle valve (233) is located on the long control oil pipe (26); The first liquid outlet pipe (224) is connected with the first return pipe (225) through the second return pipe (242), and the second pressure compensation valve (243) is arranged on the second return pipe (242); the second pressure compensation valve (243) is connected with the long control oil pipe (26) through the third return pipe (244), the first liquid outlet pipe (224) is connected with the long liquid return pipe (25) through the fourth return pipe (245), and the third overflow valve (246) is arranged on the fourth return pipe (245); the fourth return pipe (245) is connected with the third return pipe (244); the first liquid outlet pipe (224) is connected with the long liquid return pipe (25) through the pressure reducing valve (247) and the fourth overflow valve (248).

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