Hydraulic walking system and crawler operation machine

Abstract

The hydraulic walking system comprises an oil tank, an oil supplementing pump, a plunger pump assembly and a motor assembly, the plunger pump assembly comprises a plunger pump and a plunger pump adjusting assembly, the motor assembly comprises a motor and a motor adjusting assembly, the displacement of the plunger pump is controlled through the plunger pump adjusting assembly, and then the rotating speed of the motor is changed. The motor displacement is adjusted through the motor adjusting assembly, and the rotating speed of the motor is further adjusted. According to the hydraulic walking system and the crawler operation machine, parking gear shifting and extra gear shifting operation are not needed during transition acceleration, continuous change of motor displacement is achieved, and therefore stepless speed change of the walking speed is achieved; meanwhile, gear shifting operation in the advancing process is prevented, large pressure change caused by two-point displacement change of the motor in the advancing process is avoided, impact on a control valve set and the motor is reduced, and the service life is prolonged.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery, and in particular to a hydraulic walking system and a tracked work machine. Background Technology

[0002] Among agricultural machinery, tracked work machines are commonly used in paddy fields, and their performance affects various aspects such as work efficiency and ease of operation for users.

[0003] In this linkage technology, tracked work machines use two-point control of motor displacement changes to achieve gear shifting. When the work machine is operating, the motor is in a low-speed, high-torque state with maximum displacement. When relocation is required, the motor displacement is directly switched to a smaller displacement state via a gear shifting operation, resulting in a high-speed, low-torque output and achieving higher-speed movement. This linkage technology requires the user to park and perform gear shifting operations, which is relatively complex and demanding. Furthermore, sudden speed changes during forward movement can lead to poor operability and certain dangers. Additionally, this control method is prone to two-point displacement changes in the motor during forward movement, resulting in large pressure fluctuations that exert significant impact on both the motor and the control valve assembly, affecting their service life.

[0004] Therefore, it is necessary to provide a hydraulic walking system and a tracked work machine to overcome the defects mentioned above. Utility Model Content

[0005] The purpose of this invention is to provide a hydraulic walking system and a tracked work machine, which reduces the operational complexity of tracked work machines when the speed changes during site transitions and the poor operability caused by sudden speed changes. At the same time, it avoids excessive pressure changes caused by the two-point displacement change of the motor during forward movement, which helps to prevent large impacts on the control valve group and motor due to large pressure changes, and improves the service life of the product.

[0006] According to one aspect of this utility model, a hydraulic walking system is provided, including an oil tank, a replenishing pump, a plunger pump assembly, and a motor assembly. The plunger pump assembly includes a plunger pump and a plunger pump regulating assembly for controlling the displacement of the plunger pump. The motor assembly includes a motor and a motor regulating assembly for controlling the displacement of the motor. The replenishing pump pumps oil to the plunger pump. The displacement of the plunger pump is controlled by the plunger pump regulating assembly, thereby changing the speed of the motor. The motor regulating assembly adjusts the motor displacement, further adjusting the motor speed. With this solution, no parking shifting or additional shifting operations are required during acceleration, reducing the difficulty and high requirements of shifting operations. It prevents shifting operations during forward movement, which can cause sudden speed changes and poor maneuverability. It achieves continuous change of motor displacement, thus realizing stepless speed regulation. Simultaneously, it prevents shifting operations during forward movement, avoiding large pressure changes caused by two-point displacement changes in the motor during forward movement, reducing the impact on the control valve assembly and motor, and improving service life.

[0007] Preferably, the replenishing pump pumps oil to the plunger pump, and the plunger pump's displacement is controlled by the plunger pump regulating component, thereby changing the motor speed. When the plunger pump's displacement reaches its maximum, the motor regulating component adjusts the motor's displacement to further increase the motor speed. This scheme helps achieve continuous changes in motor displacement, eliminating the need for additional gear shifting operations during acceleration, improving the ease of gear shifting, reducing the difficulty of gear shifting, and enhancing user operability.

[0008] Preferably, the plunger pump regulating assembly includes a first hydraulic cylinder connected to the plunger pump, a first control valve connected to the first hydraulic cylinder, and a plunger pump swashplate for adjusting the displacement of the plunger pump. The first control valve controls the movement of the first hydraulic cylinder to adjust the angle of the plunger pump swashplate, thereby adjusting the displacement of the plunger pump. The first control valve is connected to a make-up pump. This scheme helps to achieve displacement regulation of the plunger pump.

[0009] Preferably, the motor adjustment assembly includes a second hydraulic cylinder connected to the motor, a second control valve communicating with the second hydraulic cylinder, and a motor swashplate for adjusting the motor's displacement. The second control valve controls the movement of the second hydraulic cylinder to adjust the angle of the motor swashplate, thereby adjusting the motor's displacement. This scheme helps to achieve the adjustment and control of continuous changes in motor displacement.

[0010] Preferably, the hydraulic travel system further includes a travel control valve assembly, which is connected to the replenishing pump and the motor adjustment component. When a speed change signal is output, the piston pump adjustment component changes the displacement of the piston pump, thereby changing the speed of the travel motor. When the piston pump displacement reaches its maximum, the travel control valve assembly controls the motor adjustment component to change the motor displacement, thus changing the motor speed, thereby realizing the continuously variable transmission (CVT) function of the hydraulic travel system. This solution helps to better achieve continuous changes in motor displacement, eliminating the need for parking and gear shifting during acceleration during site transitions, thus achieving CVT while reducing the difficulty and high requirements of gear shifting operations.

[0011] Preferably, the travel control valve assembly includes a third control valve connected to the second control valve. The third control valve is used to control the action of the second control valve, thereby adjusting the motor displacement. This solution helps to achieve continuous variation of motor displacement, eliminating the need for parking and gear shifting or additional gear shifting operations during acceleration during site transitions. It enables continuously variable transmission of hydraulic travel while reducing the difficulty and high requirements of gear shifting operations.

[0012] Preferably, the second control valve is a two-position three-way proportional valve. The second control valve includes a first oil port, a second oil port, a third oil port, and a control oil port. The first oil port is connected to the rodless chamber of the second cylinder, the second oil port is connected to the rod chamber of the second cylinder, the third oil port is connected to the oil tank, and the control oil port is connected to the third control valve to control the action of the second control valve.

[0013] Preferably, the third control valve is a two-position three-way electromagnetic proportional valve, which includes a fourth oil port connected to the replenishing pump, a fifth oil port connected to the oil tank, and a sixth oil port connected to the second control valve. Preferably, the motor assembly also includes a first check valve and a second check valve, wherein the first check valve is connected to the second oil port and one end of the motor, and the second check valve is connected to the second oil port and the other end of the motor.

[0014] Preferably, the plunger pump assembly includes a first plunger pump assembly and a second plunger pump assembly, and the first plunger pump assembly and the second plunger pump assembly have the same structure.

[0015] Preferably, the plunger pump assembly further includes a first safety valve connected to one end of the plunger pump and the replenishing pump, and a second safety valve connected to the other end of the plunger pump and the replenishing pump.

[0016] Preferably, the first plunger pump assembly is used for the left-side traveling track, and the first plunger pump assembly includes a first plunger pump and a first plunger pump regulating assembly for controlling the displacement of the first plunger pump.

[0017] Preferably, the first plunger pump adjustment assembly includes a left first cylinder connected to the first plunger pump, a left first control valve connected to the left first cylinder, and a first plunger pump swashplate for adjusting the displacement of the first plunger pump. The left first control valve controls the movement of the left first cylinder to adjust the angle of the first plunger pump swashplate to adjust the displacement of the first plunger pump. The left first control valve is connected to a make-up pump.

[0018] Preferably, the second plunger pump assembly is used for the right-side traveling track, and the second plunger pump assembly includes a second plunger pump and a second plunger pump regulating assembly for controlling the displacement of the second plunger pump.

[0019] Preferably, the second plunger pump adjustment assembly includes a right first cylinder connected to the second plunger pump, a right first control valve connected to the right first cylinder, and a second plunger pump swashplate for adjusting the displacement of the second plunger pump. The right first control valve controls the movement of the right first cylinder to adjust the angle of the second plunger pump swashplate to adjust the displacement of the second plunger pump. The right first control valve is connected to a make-up pump.

[0020] Preferably, the motor assembly includes a first motor assembly connected to a first plunger pump assembly and a second motor assembly connected to a second plunger pump assembly, wherein the first motor assembly and the second motor assembly have the same structure.

[0021] Preferably, the motor assembly further includes a third hydraulic cylinder for braking, connected to the travel motor.

[0022] Preferably, the first motor assembly is used for the left-side walking track and includes a first motor and a first motor adjustment assembly for controlling the displacement of the first motor.

[0023] Preferably, the first motor adjustment assembly includes a left second hydraulic cylinder connected to the first motor, a left second control valve communicating with the left second hydraulic cylinder, and a first motor swashplate for adjusting the displacement of the first motor. The left second control valve controls the movement of the left second hydraulic cylinder to adjust the angle of the first motor swashplate to adjust the displacement of the first motor.

[0024] Preferably, the second motor assembly is used for the right-side walking track and includes a second motor and a second motor adjustment assembly for controlling the displacement of the second motor.

[0025] Preferably, the second motor adjustment assembly includes a right-side second hydraulic cylinder connected to the second motor, a right-side second control valve communicating with the right-side second hydraulic cylinder, and a second motor swashplate for adjusting the displacement of the second motor. The right-side second control valve controls the movement of the right-side second hydraulic cylinder to adjust the angle of the second motor swashplate, thereby adjusting the displacement of the second motor.

[0026] Preferably, the travel control valve assembly further includes a fourth control valve connected to the third cylinder for controlling the third cylinder.

[0027] Preferably, the third control valve includes a first third control valve that controls the first motor assembly and a second third control valve that controls the second motor assembly.

[0028] Preferably, the motor assembly also includes a flushing valve for cooling, which is connected to the motor and connected to the oil tank. This design helps to cool the hydraulic oil.

[0029] Preferably, the hydraulic travel system further includes a filter, a return oil circuit, and a radiator connecting the return oil circuit and the oil tank. A first relief valve, connected in parallel with the radiator, is also included between the return oil circuit and the oil tank. The radiator helps to dissipate heat from the hydraulic oil; the first relief valve helps to protect the radiator, preventing blockage caused by the hydraulic oil being too viscous and unable to flow to the radiator.

[0030] Preferably, a second relief valve is connected between the replenishing pump and the plunger pump assembly. This design helps to control excessive oil pressure in the first control valve.

[0031] Preferably, the travel control valve group further includes a third relief valve, which is connected to the travel control valve group and the oil replenishment pump, while the first relief valve is connected to the oil tank.

[0032] Preferably, this utility model also provides a tracked work machine, including a main gear shift handle, a controller connected to the main gear shift handle, and the aforementioned hydraulic walking system. When the main gear shift handle is pushed, a gear shift signal is output, and the controller sends a gear shift command to the piston pump assembly. The first control valve changes the displacement of the piston pump, thereby changing the motor speed. When the displacement of the piston pump reaches its maximum, the controller sends a shift command to the third control valve. The third control valve controls the oil pressure at the input port of the second control valve, changing the oil pressure at the input port of the second control valve. This causes the second control valve to control the motor adjustment assembly to change the displacement of the walking motor, thereby changing the motor speed, thus realizing the continuously variable transmission function of the tracked work machine. With the above solution, no additional gear shifting operation is required during site transition acceleration. The motor displacement is continuously reduced through the main gear shift handle, thereby achieving continuously variable transmission and increasing walking speed. During operation, by pushing the gear shift handle in the opposite direction, the walking speed is reduced, and the motor output torque is continuously increased, thereby achieving the larger motor output torque required for operation.

[0033] This utility model provides a hydraulic walking system and tracked work machine, including an oil tank, a replenishing pump, a plunger pump assembly, and a motor assembly. The displacement of the plunger pump is controlled by the plunger pump adjustment assembly, thereby changing the speed of the motor. The motor displacement is adjusted by the motor adjustment assembly, further adjusting the speed of the motor. When accelerating during a changeover, there is no need to stop and shift gears or perform additional gear shifting operations, reducing the difficulty and high requirements of gear shifting operations. It prevents gear shifting operations during forward movement, which can cause sudden changes in speed and large pressure changes due to changes in the two-point displacement of the motor. This reduces the impact on the control valve assembly and motor, and improves their service life. Attached Figure Description

[0034] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments:

[0035] Figure 1 This is the overall hydraulic control diagram of the hydraulic walking system;

[0036] Figure 2 for Figure 1 Enlarged view of a portion of the first plunger pump assembly;

[0037] Figure 3 for Figure 1 Enlarged view of a portion of the second plunger pump assembly;

[0038] Figure 4 for Figure 1 Enlarged view of a portion of the first motor assembly;

[0039] Figure 5 for Figure 1 Enlarged view of a portion of the second motor assembly;

[0040] Figure 6 for Figure 1 A partial enlarged view of the travel control valve assembly;

[0041] Figure 7 This is the control flowchart for the hydraulic walking system;

[0042] Figure 8 a is a graph showing the relationship between the main gear shift lever stroke and the piston pump displacement in this application;

[0043] Figure 8 b is a graph showing the relationship between the main gear shift lever stroke and the motor displacement in this application;

[0044] Figure 9 a is a graph showing the relationship between the main gear shift lever travel and the walking speed in this application;

[0045] Figure 9 b is a graph showing the relationship between the main gear shift lever travel and the motor drive torque in this application;

[0046] Figure 10 a is a graph showing the relationship between the main gear shift lever stroke and the piston pump displacement in the two-point control scheme for motor displacement;

[0047] Figure 10 b is a graph showing the relationship between the main gear shift lever travel and the motor displacement change in the two-point control scheme for motor displacement.

[0048] Figure 11 a is a graph showing the relationship between the main gear shift lever travel and the walking speed in the two-point control scheme for motor displacement;

[0049] Figure 11 Figure b shows the relationship between the main gear shift lever travel and the motor drive torque in the two-point control scheme for motor displacement.

[0050] Explanation of icon numbers:

[0051] 1. Plunger pump assembly; 1a. First plunger pump assembly; 1b. Second plunger pump assembly; 2. Motor assembly; 2a. First motor assembly; 2b. Second motor assembly; 3. Travel control valve assembly; 4. Radiator; 5. First relief valve; 6. Oil tank; 7. Second relief valve; 8. Filter; 9. Make-up pump; 10. Plunger pump adjusting assembly; 10a. First plunger pump adjusting assembly; 10b. Second plunger pump adjusting assembly; 11. Plunger pump; 11a. First plunger pump; 11b, Second plunger pump; 20, Motor adjusting assembly; 20a, First motor adjusting assembly; 20b, Second motor adjusting assembly; 21, Motor; 21a, First motor; 21b, Second motor; 101, First control valve; 101a, Left first control valve; 101b, Right first control valve; 102, First cylinder; 102a, Left first cylinder; 102b, Right first cylinder; 103, Plunger pump swashplate; 103a, First plunger pump swashplate; 103b, Second plunger pump swashplate; 104, First safety valve; 105, Second safety valve; 201, Second control valve; 201a, Left second control valve; 201b, Right second control valve; 2011, First oil port; 2012, Second oil port; 2013, Third oil port; 2014, Control oil port; 202, Second cylinder; 202a, Left second cylinder; 202b, Right second cylinder; 203, Flushing valve; 204, Flushing valve overflow valve; 205. First check valve; 206. Second check valve; 207. Motor swashplate; 207a. First motor swashplate; 207b. Second motor swashplate; 208. Third cylinder; 301. Fourth control valve; 302. Third control valve; 302a. First and third control valves; 302b. Second and third control valves; 3021. Fourth oil port; 3022. Fifth oil port; 3023. Sixth oil port; 303. Third relief valve; F1. Throttle valve; h. Return oil circuit. Detailed Implementation

[0052] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0053] To keep the drawings concise, only the parts relevant to this invention are shown schematically in each figure, and they do not represent the actual structure of the product. Furthermore, for ease of understanding, in some figures, only one of the components with the same structure or function is schematically depicted, or only one is labeled. In this document, "one" not only means "only one," but can also mean "more than one."

[0054] It should also be further understood that the term “and / or” as used in this application specification and the appended claims means any combination of one or more of the associated listed items and all possible combinations, and includes such combinations.

[0055] In this document, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to fixed connections, detachable connections, or integral connections; they can refer to mechanical connections or electrical connections; they can refer to direct connections or indirect connections through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0056] Furthermore, in the description of this application, the terms "first," "second," "left," "right," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0057] To more clearly illustrate the technical solutions in the embodiments of this utility model or the prior art, the specific implementation methods of this utility model will be described below with reference to the accompanying drawings. Obviously, the drawings described below are merely some embodiments of this utility model. For those skilled in the art, other drawings and other implementation methods can be obtained based on these drawings without any creative effort.

[0058] See Figures 1 to 11As shown, this embodiment provides a hydraulic walking system, including an oil tank 6, a replenishing pump 9, a plunger pump assembly 1, and a motor assembly 2. The plunger pump assembly 1 includes a plunger pump 11 and a plunger pump regulating assembly 10 for controlling the displacement of the plunger pump 11. The motor assembly 2 includes a motor 21 and a motor regulating assembly 20 for controlling the displacement of the motor 21. The replenishing pump 9 pumps oil to the plunger pump 11. The displacement of the plunger pump 11 is controlled by the plunger pump regulating assembly 10, thereby changing the speed of the motor 21. The displacement of the motor 21 is adjusted by the motor regulating assembly 20, further adjusting the speed of the motor 21. During acceleration during transit, there is no need to park and shift gears or perform additional gear shifting operations, reducing the difficulty and high requirements of gear shifting operations. This prevents gear shifting operations during forward movement, which could cause sudden changes in speed and poor maneuverability. It enables continuous changes in the displacement of motor 21, thereby achieving stepless speed regulation. At the same time, it prevents gear shifting operations during forward movement, avoiding large pressure changes caused by the original two-point displacement changes of motor 21 during forward movement, reducing the impact on the control valve assembly and motor 21, and improving service life.

[0059] See Figure 1 As shown, the oil replenishment pump 9 pumps oil to the plunger pump 11. The displacement of the plunger pump 11 is controlled by the plunger pump adjustment component 10, which in turn changes the speed of the motor 21. When the displacement of the plunger pump 11 reaches its maximum, the displacement of the motor 21 is adjusted by the motor adjustment component 20 to further increase the speed of the motor 21. This helps to achieve continuous change in the displacement of the motor 21. No additional gear shifting operation is required during acceleration, which improves the ease of gear shifting operation, reduces the difficulty of gear shifting, and improves the user's operability.

[0060] The hydraulic walking system also includes a walking control valve assembly 3, which is connected to the replenishing oil pump 9 and the motor adjustment assembly 20. When a speed change signal is output, the displacement of the piston pump 11 is changed by the piston pump adjustment assembly 10, thereby changing the speed of the walking motor 21. When the displacement of the piston pump 11 reaches its maximum, the motor adjustment assembly 20 is controlled by the walking control valve assembly 3 to change the displacement of the motor 21 and thus change the speed of the motor 21, thereby realizing the stepless speed change function of the hydraulic walking system.

[0061] The hydraulic travel system also includes a filter 8, a return oil line h, and a radiator 4 connecting the return oil line h and the oil tank 6. The filter 8 connects the oil tank 6 and the replenishing pump 9. The return oil line h and the oil tank 6 also include a first relief valve 5 connected in parallel with the radiator 4. The radiator 4 dissipates heat from the hydraulic oil, and the first relief valve 5 protects the radiator 4, preventing blockage caused by the hydraulic oil being too viscous and unable to flow to the radiator 4. A second relief valve 7 connects the replenishing pump 9 and the plunger pump assembly 1 to prevent the oil pressure entering the plunger pump assembly 1 from being too high.

[0062] See Figure 1 , Figure 3 and Figure 4 As shown, the plunger pump regulating assembly 10 includes a first cylinder 102 connected to the plunger pump, a first control valve 101 connected to the first cylinder 102, and a plunger pump swashplate 103 for adjusting the displacement of the plunger pump 11. The first control valve 101 controls the first cylinder 102 to adjust the angle of the plunger pump swashplate 103 to adjust the displacement of the plunger pump 11. The first control valve 101 is connected to the make-up pump 9. When the main gear shift lever is pushed, the controller sends a control signal to the first control valve 101, thereby realizing the displacement regulation control of the plunger pump 11.

[0063] The plunger pump assembly 1 includes a first plunger pump assembly 1a and a second plunger pump assembly 1b, with the first plunger pump assembly 1a and the second plunger pump assembly 1b having the same structure. The plunger pump assembly 1 also includes a first safety valve 104 connected to one end of the plunger pump 11 and the replenishing pump 9, and a second safety valve 105 connected to the other end of the plunger pump 11 and the replenishing pump 9.

[0064] See Figure 3 As shown, the first plunger pump assembly 1a is used for the left-side traveling track. The first plunger pump assembly 1a includes a first plunger pump 11a and a first plunger pump regulating assembly 10a for controlling the displacement of the first plunger pump 11a.

[0065] The first plunger pump regulating assembly 10a includes a left first cylinder 102a connected to the first plunger pump 11a, a left first control valve 101a connected to the left first cylinder 102a, and a first plunger pump swashplate 103a for adjusting the displacement of the first plunger pump 11a. The left first control valve 101a controls the action of the left first cylinder 102a to adjust the angle of the first plunger pump swashplate 103a to adjust the displacement of the first plunger pump 11a. The left first control valve 101a is connected to the make-up pump 9.

[0066] See Figure 4 As shown, the second plunger pump assembly 1b is used for the right-side traveling track. The second plunger pump assembly 1b includes a second plunger pump 11b and a first plunger pump regulating assembly 10b for controlling the displacement of the second plunger pump 11b.

[0067] The first plunger pump regulating assembly 10b includes a right first cylinder 102b connected to the second plunger pump 11b, a right first control valve 101b connected to the right first cylinder 102b, and a second plunger pump swashplate 103b for adjusting the displacement of the second plunger pump 11b. The right first control valve 101b controls the right first cylinder 102b to adjust the angle of the second plunger pump swashplate 103b to adjust the displacement of the second plunger pump 11b. The right first control valve 101b is connected to the make-up pump 9.

[0068] See Figure 1 , Figure 4 and Figure 5 As shown, the motor adjustment assembly 20 includes a second hydraulic cylinder 202 connected to the motor 21, a second control valve 201 communicating with the second hydraulic cylinder 202, and a motor swashplate 207 for adjusting the displacement of the motor. The second control valve 201 controls the movement of the second hydraulic cylinder 202 to adjust the angle of the motor swashplate 207 to adjust the displacement of the motor 21.

[0069] The second control valve 201 is a two-position three-way proportional valve. The second control valve 201 includes a first oil port 2011, a second oil port 2012, a third oil port 2013, and a control oil port 2014. The first oil port 2011 is connected to the rodless chamber of the second cylinder 202, the second oil port 2012 is connected to the rod chamber of the second cylinder 202, the third oil port 2013 is connected to the oil tank 6, and the control oil port 2014 is connected to the third control valve 302. The third control valve 302 controls the operation of the second control valve 201.

[0070] The motor assembly 2 also includes a first check valve 205 and a second check valve 206. The first check valve 205 is connected to the second oil port 2012 and one end of the motor 21, and the second check valve 206 is connected to the second oil port 2012 and the other end of the motor 21.

[0071] The motor assembly 2 also includes a third hydraulic cylinder 208 connected to the travel motor 21 for braking.

[0072] The motor assembly 2 also includes a flushing valve 203, a flushing valve relief valve 204, and a throttle valve F1. The flushing valve 203 is connected to the motor 21 and the oil tank 6 to cool the hydraulic oil. The flushing valve relief valve 204 connects the flushing valve 203 and the oil tank 6, and the throttle valve F1 connects the oil tank 6 and the flushing valve 203.

[0073] The motor assembly 2 includes a first motor assembly 2a connected to the first plunger pump assembly 1a and a second motor assembly 2b connected to the second plunger pump assembly 1b. The first motor assembly 2a and the second motor assembly 2b have the same structure.

[0074] See Figure 4 As shown, the first motor assembly 2a is used to drive the left-side walking track, including a first motor 21a and a first motor adjustment assembly 20a for controlling the displacement of the first motor 21a.

[0075] The first motor adjustment assembly 20a includes a left second cylinder 202a connected to the first motor 21a, a left second control valve 201a connected to the left second cylinder 202a, and a first motor swashplate 207a for adjusting the displacement of the first motor 21a. The left second control valve 201a controls the movement of the left second cylinder 202a to adjust the angle of the first motor swashplate 207a to adjust the displacement of the first motor 21a.

[0076] See Figure 5 As shown, the second motor assembly 2b is used to drive the right-side track, and includes a second motor 21b and a second motor adjustment assembly 20b for controlling the displacement of the second motor 21b.

[0077] Preferably, the second motor adjustment assembly 20b includes a right second cylinder 202b connected to the second motor 21b, a right second control valve 201b communicating with the right second cylinder 202b, and a second motor swashplate 207b for adjusting the displacement of the second motor 21b. The right second control valve 201b controls the movement of the right second cylinder 202b to adjust the angle of the second motor swashplate 207b, thereby adjusting the displacement of the second motor 21b.

[0078] See Figure 1 and Figure 6 As shown, the travel control valve group 3 includes a third control valve 302 connected to the second control valve 201. The third control valve 302 controls the action of the second control valve 201, thereby adjusting the motor displacement. The travel control valve group 3 also includes a third relief valve 303, which is connected to the travel control valve group 3 and the oil replenishment pump 9. The third relief valve 303 is also connected to the oil tank 6. During acceleration during a transfer, the controller controls the third control valve 302, thereby changing the oil pressure at the inlet of the second control valve 201. This causes the second control valve 201 to actuate, which in turn causes the second cylinder 202 to drive the motor swashplate 207, changing the displacement of the motor 21. This achieves continuously variable transmission (CVT) for hydraulic travel, while reducing the difficulty of gear shifting and lowering the requirements for high-speed gear shifting.

[0079] See Figure 6 As shown, the third control valve 302 is a two-position three-way electromagnetic proportional valve. The third control valve 302 includes a fourth oil port 3021 connected to the oil replenishment pump 9, a fifth oil port 3022 connected to the oil tank 6, and a sixth oil port 3023 connected to the second control valve 201.

[0080] The travel control valve group 3 also includes a fourth control valve 301 connected to the third cylinder 208 for controlling the third cylinder 208. The third cylinder 208 is braked by the fourth control valve 301. The travel control valve group 3 also includes a throttle valve F1 connecting the fourth control valve 301 and the third cylinder 208.

[0081] The third control valve 302 includes a first third control valve 302a that controls the first motor assembly 2a and a second third control valve 302b that controls the second motor assembly 2b. The first and third control valves 302a are connected to the left second control valve 201a to control the first motor assembly 2a for the left track. Furthermore, the first and third control valves 302a are connected to the control port 2014 of the left second control valve 201a. By controlling the left second control valve 201a, the extension and retraction of the left second cylinder 202a is controlled, causing the first motor swashplate 207a to adjust its angle, thereby controlling the displacement of the first motor 21a. The second and third control valves 302b are connected to the right second control valve 201b to control the second motor assembly 2b for the right track. Furthermore, the second and third control valves 302b are connected to the control port 2014 of the right second control valve 201b. By controlling the right second control valve 201b, the extension and retraction of the right second cylinder 202b is controlled, causing the second motor swashplate 207b to adjust its angle, thereby controlling the displacement of the second motor 21b.

[0082] See Figure 7 The diagram shows the control flow of this embodiment. The steering assembly includes a steering wheel and a brake button. The steering wheel outputs a steering angle signal to the controller, and the brake button outputs a braking signal to the controller. The main gear shift lever outputs a travel signal, including neutral, forward and forward speed, and reverse and reverse speed.

[0083] The controller collects the input signal from the steering wheel and the speed signals from the first motor 21a and the second motor 21b, and sends control commands to the first control valve 101 and the travel control valve group 3 to realize the travel functions of the tracked machine, such as straight-line travel, differential travel of left and right tracks, turning on the spot, and continuously variable transmission.

[0084] When the main gear shift lever is in the neutral position, the travel signal is 0, and the controller sends a command to the first control valve 101. At this time, the flow rates of the first plunger pump 11a and the second plunger pump 11b are 0, and the tracked machine does not travel.

[0085] When the main gear shift lever is in the forward position, a forward signal is output, and the controller sends a command to the first control valve 101. At this time, the flow rate of the first plunger pump 11a is the same as that of the second plunger pump 11b, and the flow rate is consistent with the signal level, so that the output speed of the first motor 21a and the second motor 21b is the same, and the tracked machine moves forward in a straight line.

[0086] When the main gear shift lever is in the reverse position, a reverse signal is output, and the controller sends a command to the first control valve 101. At this time, the flow rate of the first plunger pump 11a is the same as that of the second plunger pump 11b, and the flow rate is consistent with the signal level, so that the output speed of the first motor 21a and the second motor 21b is the same, and the direction of rotation is opposite to the forward direction, and the tracked machine reverses in a straight line.

[0087] When the main gear shift lever is pushed, a gear shift signal is output, and the controller sends a gear shift command to the first control valve 101. By changing the pumping flow of the plunger pump 11, the speed of the motor 21 is changed accordingly. When the pumping flow of the plunger pump 11 reaches its maximum, the controller sends a shift command to the third control valve 302 of the travel control valve group 3. By changing the oil pressure at the control port 2014 of the second control valve 201 in the motor assembly 2, the second control valve 201 is activated, which controls the second cylinder 202 to work, changing the displacement of the motor 21, thereby changing the output speed of the motor 21. The output speed of the motor 21 is different when the piston of the second cylinder 202 is in different positions, realizing the stepless speed change function of the travel hydraulic system.

[0088] When the brake button in the steering assembly is operated, a brake signal is output, and the controller sends a brake command to the first control valve 101 to reduce and stop the flow of the plunger pump 11. At the same time, a brake command is sent to the fourth control valve 301 of the travel control valve to control the third cylinder 208 to work, so that the brake pads work and the whole vehicle is braked.

[0089] As the travel of the main shift lever increases, in the initial travel of the main shift lever, the displacement of motor 21 remains at its maximum, while the displacement of piston pump 11 increases. At this time, the speed of the whole machine gradually increases, and the maximum output torque of motor 21 remains unchanged. In the later travel of the main shift lever, the displacement of piston pump 11 remains at its maximum, while the displacement of motor 21 decreases. At this time, the speed of the whole machine gradually increases, and the maximum output torque of motor 21 gradually decreases.

[0090] See Figure 8 As shown in Figure a, the relationship between the main shift lever stroke and the displacement of the piston pump 11 in this embodiment is given. As the main shift lever stroke increases, the displacement of the piston pump 11 gradually increases in the initial stroke and reaches its maximum value. In the later stroke, as the main shift lever stroke continues to increase, the displacement of the piston pump 11 remains at its maximum.

[0091] See Figure 8 As shown in Figure b, the relationship between the main shift lever stroke and the motor 21 displacement in this embodiment is given. As the main shift lever stroke increases, the motor 21 displacement remains at its maximum during the initial stroke. During the later stroke, as the main shift lever stroke continues to increase, the motor 21 displacement gradually decreases and eventually reaches the minimum motor 21 displacement value.

[0092] See Figure 9 As shown in Figure a, a graph showing the relationship between the travel of the main gear shift lever and the walking speed in this embodiment is presented. As the travel of the main gear shift lever increases, the walking speed, i.e., the output speed of motor 21, gradually increases.

[0093] See Figure 9 As shown in Figure b, the relationship between the main shift lever travel and the driving torque of motor 21 in this embodiment is given. As the main shift lever travel increases, the driving torque of motor 21 remains at its maximum in the first part of the travel, and gradually decreases in the second part of the travel as the main shift lever travel continues to increase.

[0094] See Figure 10 As shown in Figure a, the relationship between the stroke of the main gear shift lever and the displacement of the piston pump 11 under the two-point control scheme of the motor 21 displacement is given. As the stroke of the main gear shift lever increases, the displacement of the piston pump 11 gradually increases.

[0095] See Figure 10 As shown in Figure b, the relationship between the main gear shift lever stroke and the displacement of motor 21 under the two-point control scheme of motor 21 displacement is given, where the displacement of motor 21 remains constant at either the maximum or minimum displacement.

[0096] See Figure 11 As shown in Figure a, a graph is given showing the relationship between the travel speed and the main gear shift lever stroke under the two-point control scheme of the 21-displacement motor. As the travel speed of the main gear shift lever increases, the travel speed gradually increases according to a certain linear change.

[0097] See Figure 11 As shown in Figure b, the relationship between the main gear shift lever travel and the drive torque of motor 21 under the two-point control scheme of motor 21 displacement is presented. The output torque of motor 21 remains constant at a fixed value that is either at its maximum or less than the maximum output torque. When the walking speed is low, the displacement of motor 21 remains at its maximum value, and the drive torque of motor 21 remains at its maximum torque value.

[0098] The driving force of motor 21 depends on the displacement of motor 21 and the pressure of hydraulic system. In the first stroke, the speed of motor 21 is changed by controlling the displacement of piston pump 11 for harvesting and other operations, and the output torque of motor 21 remains unchanged. In the second stroke, the speed of motor 21 is changed by changing the displacement of motor 21. Decreasing the displacement of motor 21 and increasing the speed of motor 21 can better enable it to be used for on-road travel and relocation.

[0099] This utility model also provides a tracked work machine, including a main gear shift handle, a controller connected to the main gear shift handle, and the aforementioned hydraulic walking system. When the main gear shift handle is pushed, a gear shift signal is output, and the controller sends a gear shift command to the piston pump assembly 1. The displacement of the piston pump 11 is changed through the first control valve 101, thereby changing the speed of the motor 21. When the displacement of the piston pump 11 reaches its maximum, the controller sends a shift command to the third control valve 302. The third control valve 302 controls the oil pressure at the input port of the second control valve 201, changing the oil pressure at the input port of the second control valve 201, so that the second control valve 201 controls the shift cylinder to change the displacement of the motor 21, thereby changing the speed of the motor 21, realizing the continuously variable transmission function of the tracked work machine. No additional gear shifting is required during acceleration during site transitions. The displacement of motor 21 is continuously reduced by the main gear shift lever, thereby achieving continuously variable speed increase of walking speed. During operation, the walking speed is reduced by pushing the gear shift lever in the opposite direction, thereby achieving continuously variable increase of motor 21 output torque, thus achieving the larger motor 21 output torque required during operation.

[0100] This embodiment provides a hydraulic walking system and tracked work machine, including an oil tank, a replenishing pump, a plunger pump assembly 1, and a motor assembly 2. The displacement of the plunger pump 11 is controlled by the plunger pump regulating assembly 10, thereby changing the speed of the motor 21. The displacement of the motor 21 is adjusted by the motor regulating assembly 20, further adjusting the speed of the motor 21. When accelerating during a changeover, there is no need to stop and shift gears or perform additional gear shifting operations, reducing the difficulty and high requirements of gear shifting operations. This prevents gear shifting operations during forward movement, which could lead to sudden speed changes after gear shifting and large pressure changes caused by changes in the two-point displacement of the motor 21. This reduces the impact on the control valve assembly and the motor 21, and improves their service life.

[0101] It will be apparent to those skilled in the art that various modifications and variations can be made to the exemplary embodiments of the present invention without departing from the spirit and scope of the present invention. Therefore, it is intended that the present invention cover modifications and variations falling within the scope of the appended claims and their equivalents.

Claims

1. A hydraulic walking system, characterized by, The hydraulic walking system comprises: a tank; a compensation pump; a plunger pump assembly, which comprises a plunger pump and a plunger pump adjusting assembly for controlling the displacement of the plunger pump; a motor assembly, which comprises a motor and a motor adjusting assembly for controlling the displacement of the motor; the compensation pump pumps oil to the plunger pump, the displacement of the plunger pump is controlled by the plunger pump adjusting assembly, thereby changing the rotating speed of the motor, the displacement of the motor is adjusted by the motor adjusting assembly, and the rotating speed of the motor is further adjusted.

2. A hydraulic walking system as claimed in claim 1, characterized in that the compensation pump pumps oil to the plunger pump, the displacement of the plunger pump is controlled by the plunger pump adjusting assembly, thereby changing the rotating speed of the motor, when the displacement of the plunger pump reaches the maximum, the displacement of the motor is adjusted by the motor adjusting assembly, and the rotating speed of the motor is further increased.

3. A hydraulic track system as claimed in claim 1 or 2, characterized in that the plunger pump adjusting assembly comprises a first oil cylinder connected to the plunger pump, a first control valve in communication with the first oil cylinder, and a plunger pump swash plate for adjusting the displacement of the plunger pump, the angle of the plunger pump swash plate is adjusted by controlling the action of the first oil cylinder through the first control valve, thereby adjusting the displacement of the plunger pump, and the first control valve is in communication with the compensation pump.

4. A hydraulic track system as claimed in claim 3, wherein, the motor adjusting assembly comprises a second oil cylinder connected to the motor, a second control valve in communication with the second oil cylinder, and a motor swash plate for adjusting the displacement of the motor, the angle of the motor swash plate is adjusted by controlling the action of the second oil cylinder through the second control valve, thereby adjusting the displacement of the motor.

5. A hydraulic walking system as claimed in claim 4, wherein, Further comprising: a walking control valve group, which is in communication with the compensation pump and the motor adjusting assembly, when the output variable speed signal is output, the displacement of the plunger pump is changed by the plunger pump adjusting assembly, thereby changing the rotating speed of the motor, when the displacement of the plunger pump reaches the maximum, the displacement of the motor is changed by the motor adjusting assembly through the action of the walking control valve group, thereby changing the rotating speed of the motor, and the stepless variable speed function of the hydraulic walking system is realized.

6. A hydraulic walking system as claimed in claim 5, wherein, the walking control valve group comprises a third control valve in communication with the second control valve, the third control valve is used to control the action of the second control valve, thereby adjusting the displacement of the motor.

7. A hydraulic track system as claimed in claim 6, wherein, the second control valve is a two-position three-way proportional valve, which comprises a first oil port, a second oil port, a third oil port, and a control oil port, the first oil port is in communication with the rodless chamber of the second oil cylinder, the second oil port is in communication with the rod chamber of the second oil cylinder, the third oil port is in communication with the tank, and the control oil port is in communication with the third control valve, thereby controlling the action of the second control valve through the third control valve.

8. A hydraulic track system as claimed in claim 7, wherein, the third control valve is a two-position three-way electromagnetic proportional valve, which comprises a fourth oil port in communication with the compensation pump, a fifth oil port in communication with the tank, and a sixth oil port in communication with the second control valve.

9. A hydraulic walking system as claimed in claim 8, wherein, the motor assembly further comprises a first check valve and a second check valve, the first check valve is in communication with the second oil port and one end of the motor, and the second check valve is in communication with the second oil port and the other end of the motor.

10. A hydraulic walking system as claimed in claim 9, wherein, The plunger pump assembly comprises a first plunger pump assembly and a second plunger pump assembly, and the first plunger pump assembly is identical in structure to the second plunger pump assembly.

11. A hydraulic walking system as claimed in claim 10, wherein, The motor assembly comprises a first motor assembly connected to the first plunger pump assembly and a second motor assembly connected to the second plunger pump assembly, and the first motor assembly and the second motor assembly are identical in structure.

12. A hydraulic track system as claimed in claim 11, wherein, The motor assembly further comprises a third oil cylinder connected to the motor for braking.

13. A hydraulic track system as claimed in claim 12, wherein, The travel control valve group further comprises a fourth control valve for controlling the third oil cylinder in communication with the third oil cylinder.

14. A hydraulic track system as claimed in claim 11 or 13, wherein, The third control valve comprises a first third control valve for controlling the first motor assembly and a second third control valve for controlling the second motor assembly.

15. A hydraulic track system as claimed in claim 14, wherein, The motor assembly further comprises a flushing valve in communication with the motor for cooling, and the flushing valve is in communication with the oil tank.

16. A hydraulic track system as claimed in claim 15, wherein, Further comprising an oil return oil circuit and a radiator in communication with the oil return oil circuit and the oil tank, and further comprising a first overflow valve in parallel with the radiator between the oil return oil circuit and the oil tank.

17. A hydraulic track system as claimed in claim 16, wherein, The second overflow valve is in communication between the oil supplement pump and the plunger pump assembly.

18. A hydraulic track system as in claim 14, wherein, The travel control valve group further comprises a third overflow valve in communication with the travel control valve group and the oil supplement pump, and the third overflow valve is in communication with the oil tank.

19. A track-type work machine characterized by, The hydraulic travel system comprises a main gear lever, a controller connected to the main gear lever, and the hydraulic travel system according to claim 1 or 18, when the main gear lever is pushed, a gear shifting signal is output, the controller sends a gear shifting instruction to the plunger pump assembly, the displacement of the plunger pump is changed through the first control valve to change the rotating speed of the motor; when the displacement of the plunger pump reaches the maximum, the controller sends a gear shifting instruction, the input oil pressure of the second control valve is changed to make the second control valve control the motor adjusting assembly to change the displacement of the motor to change the rotating speed of the motor, and the stepless gear shifting function of the track working machine is realized.

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