Hydraulic system for applying electro-hydraulic power gear shifting and stepless variable-speed motor to crawler-type green feed harvester

Abstract

The utility model discloses a hydraulic system of an electro-hydraulic power gear shifting and stepless variable-speed motor applied to a crawler-type green feed harvester, belongs to the technical field of harvester control, and solves the problems that a traditional crawler-type green feed harvester is more in power transmission links and complex in structure. A closed hydraulic pump input shaft in the closed hydraulic pump and bidirectional hydraulic motor all-in-one machine is connected with a belt pulley shaft, a bidirectional hydraulic motor output shaft in the closed hydraulic pump and bidirectional hydraulic motor all-in-one machine is connected with an input shaft of a gearbox, and the gearbox is further connected with an electro-hydraulic gear shifting mechanism and a hydraulic steering mechanism. A steering oil cylinder in the hydraulic steering mechanism is connected with a brake of an output shaft in the gearbox, the hydraulic control valve set is connected with a three-way pressure reducing valve and a two-position three-way electromagnetic reversing valve, and the two-position three-way electromagnetic reversing valve is connected with the electro-hydraulic gear shifting mechanism. According to the utility model, electro-hydraulic gear-shifting stepless speed change is realized when a traditional green feed harvester walks, and optimization and upgrading of products are realized.

Description

Technical Field

[0001] This utility model belongs to the field of harvester control technology, specifically relating to a hydraulic system for an electro-hydraulic power shift and continuously variable transmission applied to a tracked forage harvester. Background Technology

[0002] Investigations and statistics revealed that traditional tracked forage harvesters, employing an "engine-driveshaft-gearbox" power transmission system and a manual mechanical gear shifting method with levers, suffer from the following disadvantages: 1. Low transmission efficiency and high engine fuel consumption. The traditional "engine-driveshaft-gearbox" power transmission system involves numerous and complex transmission links, resulting in significant energy loss and low power transmission efficiency. To output substantial walking power, the engine consumes even more fuel. With the continuous rise in fuel prices in recent years, the operating cost of traditional forage harvesters has been steadily increasing, leading to a decline in their market popularity; 2. Unstable walking speed, easily causing driver discomfort. Since forage harvesters mostly operate in farmland, the harsh and complex terrain makes their walking speed highly unstable, easily causing varying degrees of bumps and jolting. Over time, this can easily lead to driver discomfort and increase safety risks; 3. Limited achievable walking speeds. Because the gearbox is designed with a fixed number of gears, when used in a forage harvester, it can only achieve a few travel speeds that match the gearbox's gears; 4. Mechanical manual shifting is laborious and carries the risk of shifting poorly. Traditional forage harvesters use mechanical levers for manual gear shifting, which is not only laborious but also carries the risk of shifting poorly or even failing. Over time, this increases the driver's workload and can cause discomfort, indirectly increasing the risk of accidents. Utility Model Content

[0003] The purpose of this invention is to provide a hydraulic system for applying an electro-hydraulic power shift and continuously variable transmission to a tracked forage harvester, in order to solve the problem of the traditional tracked forage harvester having many power transmission links and a complex structure.

[0004] The technical solution of this utility model is: a hydraulic system for electro-hydraulic power shifting and continuously variable transmission applied to a tracked forage harvester. The tracked forage harvester includes a gearbox and a track connected thereto, as well as a gear pump, a closed-loop hydraulic pump, and a bidirectional hydraulic motor integrated unit. The gear pump is connected to a hydraulic control valve group. The input shaft of the closed-loop hydraulic pump in the bidirectional hydraulic motor integrated unit is connected to a pulley shaft. The output shaft of the bidirectional hydraulic motor in the bidirectional hydraulic pump integrated unit is connected to the input shaft of the gearbox. The gearbox is also connected to an electro-hydraulic shifting mechanism and a hydraulic steering mechanism. The steering cylinder in the hydraulic steering mechanism is connected to the brake on the output shaft of the gearbox. The shift lever in the electro-hydraulic shifting mechanism controls the meshing of the gears on the power output shaft of the gearbox. The hydraulic control valve group is connected to a three-way pressure reducing valve and a two-position three-way solenoid directional valve. The two-position three-way solenoid directional valve is connected to the electro-hydraulic shifting mechanism.

[0005] As a further improvement of this utility model, the hydraulic control valve group includes a check valve, a flow divider / combiner valve, and a three-position four-way solenoid directional valve connected in sequence. The three-position four-way solenoid directional valve is connected to a steering cylinder. A first relief valve and a two-position two-way solenoid directional valve are also connected between the check valve and the flow divider / combiner valve. A second relief valve is also connected between the flow divider / combiner valve and the three-position four-way solenoid directional valve.

[0006] As a further improvement of this utility model, the closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine is equipped with a high-pressure filter and a radiator.

[0007] The beneficial effects of this utility model are as follows: In view of the shortcomings of traditional tracked forage harvesters, the applicant, after in-depth research and investigation, boldly innovated and specifically applied an electro-hydraulic power shift and continuously variable transmission to the tracked forage harvester. This utility model enables the traditional forage harvester to achieve electro-hydraulic shift and continuously variable transmission while walking, thereby optimizing and upgrading the product.

[0008] The key feature of this invention lies in applying an electro-hydraulic power shifting and continuously variable transmission to a tracked forage harvester. Compared to traditional tracked forage harvesters, this offers the following advantages: 1. Increased work efficiency and reduced fuel consumption: The engine powers a hydraulic pump, which directly drives a bidirectional hydraulic motor, which in turn drives the transmission. Because the new transmission has a significantly simplified structure compared to traditional forage harvester transmissions, the power transmission chain is shorter, power loss is reduced, and transmission efficiency is improved, thereby reducing engine fuel consumption; 2. Improved stability: Clearly, hydraulic transmission offers unparalleled stability, allowing the hydraulic power to... The introduction of a drive system into the tracked forage harvester undoubtedly improves its walking stability; 3. It widens the walking speed range of the forage harvester in driving mode: with the dual support of a mechanical variable closed hydraulic pump and a hydraulic shifting mechanism, the tracked forage harvester can achieve stepless speed changes from zero to full speed according to the working conditions of the forage harvester; 4. Convenient and simple operation improves the comfort of the driver: with the help of the intelligent control system, the driver only needs to move a finger on the human-machine interface of the cab control platform to change gears, which is easy, convenient and reliable, and further improves the driver's working comfort. Attached Figure Description

[0009] Figure 1 This is a system schematic diagram of this utility model.

[0010] In the diagram: 1-Gear pump; 2-Check valve; 3-First relief valve; 4-Two-position two-way solenoid directional valve; 5-Diverter / combiner valve; 6-Second relief valve; 7-Three-position four-way solenoid directional valve; 8-Steering cylinder; 9-Pressure reducing valve; 10-Two-position three-way solenoid directional valve; 11-Closed-loop hydraulic pump and bidirectional hydraulic motor integrated unit; 12-High-pressure filter; 13-Gearbox; 14-Electro-hydraulic shifting mechanism; 15-Crawler track; 16-Radiator. Detailed Implementation

[0011] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0012] like Figure 1As shown, an electro-hydraulic power shift and continuously variable transmission (CVT) hydraulic system is applied to a tracked forage harvester. The tracked forage harvester includes a gearbox 13 and a track 15 connected thereto. It also includes a gear pump 1 and a closed-loop hydraulic pump and bidirectional hydraulic motor integrated unit 11. The gear pump 1 is connected to a hydraulic control valve group. The input shaft of the closed-loop hydraulic pump in the closed-loop hydraulic pump and bidirectional hydraulic motor integrated unit 11 is connected to a pulley shaft. The output shaft of the bidirectional hydraulic motor in the closed-loop hydraulic pump and bidirectional hydraulic motor integrated unit 11 is connected to the input shaft of the gearbox 13. The gearbox 13 is also connected to an electro-hydraulic shift mechanism 14 and a hydraulic steering mechanism. The steering cylinder 8 in the hydraulic steering mechanism is connected to the brake of the output shaft in the gearbox 13. The shift lever in the electro-hydraulic shift mechanism 14 controls the meshing of the gears on the power output shaft in the gearbox 13. The hydraulic control valve group is connected to a three-way pressure reducing valve 9 and a two-position three-way solenoid directional valve 10. The two-position three-way solenoid directional valve 10 is connected to the electro-hydraulic shift mechanism 14.

[0013] The hydraulic control valve group includes a check valve 2, a flow divider / combiner valve 5, and a three-position four-way solenoid directional valve 7 connected in sequence. The three-position four-way solenoid directional valve 7 is connected to a steering cylinder 8. A first relief valve 3 and a two-position two-way solenoid directional valve 4 are also connected between the check valve 2 and the flow divider / combiner valve 5. A second relief valve 6 is also connected between the flow divider / combiner valve 5 and the three-position four-way solenoid directional valve 7.

[0014] The closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine 11 is equipped with a high-pressure filter 12 and a radiator 16.

[0015] The key to this invention lies in the fact that the entire solution requires two hydraulic pumps with different output pressures to provide hydraulic power. The closed-loop hydraulic pump (high-pressure pump) powers the bidirectional hydraulic motor, while the gear pump (low-pressure pump) powers the hydraulic steering mechanism and the electro-hydraulic shifting mechanism.

[0016] like Figure 1 As shown, the hydraulic oil output from gear pump 1 enters the diversion and combination valve 5 after passing through check valve 2. Part of the oil flowing out from diversion and combination valve 5 enters the three-position four-way solenoid directional valve 7, and the other part enters the control circuit of electro-hydraulic shifting mechanism 14. Since the required working pressure of electro-hydraulic shifting mechanism 14 is lower than the working pressure of other actuators, the pressure oil in this branch first enters the three-way pressure reducing valve 9, then passes through the two-position three-way solenoid directional valve 10, and then enters the electro-hydraulic shifting mechanism 14 to achieve the final shift.

[0017] It should be noted that in the oil supply system of gear pump 1, the function of the first relief valve 3 is to set the maximum system pressure of the system, the function of the two-position two-way solenoid directional valve 4 is to unload the branch when the control circuit of the electro-hydraulic shifting mechanism 14 is not working, and the function of the second relief valve 6 is to set the maximum working pressure of the steering cylinder 8.

[0018] The closed-loop hydraulic pump, the bidirectional hydraulic motor, the replenishing pump, the relief valve, and the check valve together constitute the integrated closed-loop hydraulic pump and bidirectional hydraulic motor unit 11. The high-pressure filter 12 filters the hydraulic oil output from the replenishing pump before sending it into the inlet circuit of the closed-loop hydraulic pump. The hydraulic oil output from the closed-loop hydraulic pump directly enters the bidirectional hydraulic motor, which is directly connected to the gearbox 13. The gearbox 13 is also directly connected to the steering cylinder 8 and the electro-hydraulic shift mechanism 14.

[0019] It should be noted that when parking is required while the forage harvester is in engine operating condition, the Pga port and Pgb port of the closed-loop hydraulic pump and bidirectional hydraulic motor integrated unit 11 are connected through the two-position two-way solenoid directional valve 4 in the electro-hydraulic shift mechanism 14, so that the pressure output from the closed-loop hydraulic pump can directly enter the pump suction port without causing the bidirectional hydraulic motor to rotate, thereby achieving the purpose of parking the forage harvester while the engine is operating.

[0020] Arrange the various hydraulic components according to Figure 1 After the hydraulic principle shown is safely connected, the optimized and upgraded forage harvester can operate in the following five states during travel:

[0021] 1. Parking state: The two-position two-way solenoid valve 4 in the hydraulic shift mechanism 14 is energized, the oil inlet and outlet of the closed hydraulic pump are connected, the bidirectional hydraulic motor does not work, and the forage harvester enters the parking state.

[0022] 2. Low-speed driving: When the low-speed solenoid valve in the hydraulic shift mechanism 14 is energized, the pressure oil drives the shift lever, the low-speed gear pair in the gearbox 13 meshes, and the forage harvester enters the low-speed driving state.

[0023] 3. High-speed driving: When the high-speed solenoid valve in the hydraulic shift mechanism 14 is energized, the pressure oil drives the shift lever, the high-speed gear pair in the gearbox 13 meshes, and the forage harvester enters the high-speed driving state.

[0024] 4. Left and right steering: When end a of the three-position four-way solenoid valve 7 is energized and end b is de-energized, the left power output shaft in the gearbox 13 of the forage harvester is braked, while the right power output shaft rotates normally. At this time, the left drive wheel of the forage harvester stops rotating, while the right drive wheel rotates normally, thus achieving left steering of the forage harvester; When end a of the three-position four-way solenoid valve 7 is de-energized and end b is energized, the right power output shaft in the gearbox 13 of the forage harvester is braked, while the left power output shaft rotates normally. At this time, the right drive wheel of the forage harvester stops rotating, while the left drive wheel rotates normally, thus achieving right steering of the forage harvester.

[0025] 5. Reversing mode: When the forage harvester needs to reverse, switch to the closed hydraulic pump working mode, and the bidirectional hydraulic motor reverses the direction, allowing the forage harvester to reverse.

[0026] The core technology of this utility model is the application of an electro-hydraulic power shifting and continuously variable transmission (CVT) mechanism to drive the tracks of a tracked forage harvester, achieving electro-hydraulic shifting and CVT. This is a novel and practical technological innovation that solves the following problems: 1. Improving the working efficiency of the forage harvester and reducing fuel consumption; 2. Improving the walking stability of the forage harvester; 3. Widening the walking speed range of the forage harvester while in motion; operation is convenient and simple, improving the driver's work comfort. All the above working states of the forage harvester are achieved through the driver's operation of the intelligent human-machine interface in the cab, which is simple, convenient, and highly reliable.

Claims

1. A hydraulic system for an electro-hydraulic power shift and continuously variable transmission applied to a crawler-type green forage harvester, characterized in that: The tracked forage harvester includes a gearbox and a track connected thereto, as well as a gear pump (1) and a closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine (11). The gear pump (1) is connected to a hydraulic control valve group. The input shaft of the closed-loop hydraulic pump in the closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine (11) is connected to a pulley shaft. The output shaft of the bidirectional hydraulic motor in the closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine (11) is connected to the input shaft of the gearbox (13). The gearbox (13) is also connected to an electro-hydraulic shifting mechanism (14) and a hydraulic steering mechanism. The steering cylinder (8) in the hydraulic steering mechanism is connected to the brake of the output shaft in the gearbox (13). The shift lever in the electro-hydraulic shifting mechanism (14) controls the meshing of each gear on the power output shaft in the gearbox (13). The hydraulic control valve group is connected to a three-way pressure reducing valve (9) and a two-position three-way solenoid directional valve (10). The two-position three-way solenoid directional valve (10) is connected to the electro-hydraulic shifting mechanism (14).

2. The hydraulic system of the electro-hydraulic power shift and continuously variable transmission applied to the tracked green forage harvester according to claim 1, characterized in that: The hydraulic control valve group includes a check valve (2), a flow divider / combiner valve (5), and a three-position four-way solenoid directional valve (7) connected in sequence. The three-position four-way solenoid directional valve (7) is connected to a steering cylinder (8). A first relief valve (3) and a two-position two-way solenoid directional valve (4) are also connected between the check valve (2) and the flow divider / combiner valve (5). A second relief valve (6) is also connected between the flow divider / combiner valve (5) and the three-position four-way solenoid directional valve (7).

3. The hydraulic system of the electro-hydraulic power shift and continuously variable transmission applied to the crawler-type green forage harvester according to claim 1 or 2, characterized in that: The closed-loop hydraulic pump and bidirectional hydraulic motor integrated machine (11) is equipped with a high-pressure filter (12) and a radiator (16).

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