Gear shifting system and agricultural machinery

Abstract

The utility model discloses a gear shifting system and agricultural machinery. An output shaft of a driving part of the gear shifting system is in transmission connection with a driving shaft of a first pump; an output shaft of the hydraulic motor is in transmission connection with an input shaft of the gearbox; two first communication ports of the hydraulic motor are communicated with two oil ports of the first pump in a one-to-one correspondence manner; the switch control valve, the hydraulic motor and the first pump are arranged in parallel; two second communication ports of the switch control valve are communicated with two oil ports of the first pump in a one-to-one correspondence manner; the output shaft of the driving part is further in transmission connection with a driving shaft of the second pump, an oil inlet of the second pump is communicated with the oil tank, an oil outlet of the second pump is communicated with a loop formed by the hydraulic motor and the first pump to supplement oil to the loop, and the oil outlet of the second pump is further communicated with a gear shifting oil inlet of the hydraulic gear shifting assembly to be used for driving gear shifting so as to enable the gearbox to shift gears. The gear shifting system is simple in structure, low in production cost, good in collaboration, good in working stability and reliability and capable of rapidly and efficiently shifting gears and prolonging the service life of the gear shifting gear ring.

Description

Technical Field

[0001] This utility model relates to the field of agricultural machinery technology, and in particular to a gear shifting system and agricultural machinery. Background Technology

[0002] Agricultural machinery walking systems can be divided into fully mechanical, fully hydraulic, and semi-hydraulic / semi-mechanical types. For the semi-hydraulic / semi-mechanical type, its basic components are: drive unit - transfer case - variable displacement pump - hydraulic motor - gearbox - axle. Its shifting principle is as follows: shift control oil controls the piston movement of the shift cylinder; the cylinder fork connected to the piston rod moves the synchronizing ring; the synchronizing ring meshes with one of the high-speed gears or low-speed gears on either side of its axis, thereby obtaining different reduction ratios to achieve the desired gear position.

[0003] Currently, one existing gear shifting system, while capable of hydraulic shifting, suffers from poor coordination and reliability. Furthermore, it requires two additional delivery pumps: one to pump shifting hydraulic oil to the hydraulic shifting assembly, and the other to replenish oil to the circuit formed by the travel variable pump and hydraulic motor, resulting in a complex structure, numerous parts, and high cost. Utility Model Content

[0004] The purpose of this invention is to provide a gear shifting system and agricultural machinery to solve the aforementioned problems existing in the gear shifting system of the prior art.

[0005] To achieve this objective, the present invention adopts the following technical solution:

[0006] A gear shifting system includes a drive component, a first pump, a hydraulic motor, a gearbox, and a hydraulic shift assembly. The output shaft of the drive component is drive-connected to the drive shaft of the first pump; the output shaft of the hydraulic motor is drive-connected to the input shaft of the gearbox; the two first communication ports of the hydraulic motor are connected one-to-one with the two oil ports of the first pump; the gear shifting system further includes:

[0007] A switch control valve, the hydraulic motor and the first pump are all connected in parallel. The two second ports of the switch control valve are connected to the two oil ports of the first pump in a one-to-one correspondence. When the switch control valve is in the first position, the two second ports are disconnected from each other. When the switch control valve is in the second position, the two second ports are connected to each other.

[0008] The output shaft of the second pump is also connected to the drive shaft of the second pump. The oil inlet of the second pump is connected to the oil tank. The oil outlet of the second pump is connected to the circuit formed by the hydraulic motor and the first pump to replenish the circuit with oil. The oil outlet of the second pump is also connected to the shift inlet of the hydraulic shift assembly for driving shifting, so that the gearbox shifts.

[0009] As a preferred embodiment of the above-mentioned shifting system, the shifting system further includes a displacement regulating assembly, wherein the oil outlet of the second pump is also connected to the displacement regulating inlet of the displacement regulating assembly, for driving the displacement regulating assembly to regulate the displacement of the first pump.

[0010] As a preferred embodiment of the above-mentioned shifting system, the first pump is a swashplate piston pump; the displacement adjustment assembly includes a first cylinder, the first cylinder including a first cylinder body and a first piston slidably disposed in the first cylinder body, the first piston dividing the chamber of the first cylinder body into two non-communicating first chambers; the first piston is connected to the swashplate of the first pump to drive the swashplate to rotate;

[0011] The two first chambers are configured to selectively connect one to the oil outlet of the second pump and the other to the oil tank, or selectively connect both to the oil tank.

[0012] As a preferred embodiment of the above-mentioned shifting system, the displacement adjustment assembly further includes a second cylinder and a first directional control valve. The second piston of the second cylinder is connected to the first valve core of the first directional control valve, and the first valve sleeve of the first directional control valve is also fixedly connected to the first piston.

[0013] The second piston can drive the first valve core to slide relative to the first valve sleeve, so that the oil outlet of the second pump is connected to one of the first chambers and the other first chamber is connected to the oil tank; the first piston can drive the first valve sleeve to slide in the same direction relative to the first valve core, so that both first chambers are connected to the oil tank.

[0014] As a preferred embodiment of the above-mentioned shifting system, the displacement regulating assembly further includes two proportional valves, and the second piston is slidably disposed in the second cylinder body of the second cylinder and divides the chamber of the second cylinder body into two non-communicating second chambers;

[0015] The oil inlets of both proportional valves are connected to the oil outlet of the second pump, and the oil outlets of the two proportional valves are connected to the two second chambers in a one-to-one correspondence.

[0016] As a preferred embodiment of the above-mentioned shifting system, the shifting system further includes two one-way relief valves, each of which includes a one-way valve and a first relief valve;

[0017] The one-way flow inlets of the two one-way relief valves are connected to the oil outlet of the second pump, and the one-way flow outlets of the two one-way relief valves are connected to the two oil ports of the first pump in a one-to-one correspondence.

[0018] The pilot port and overflow inlet of the first overflow valve of each of the one-way relief valves are connected to the one-way flow outlet of their respective one-way valves, and the overflow outlet of the first overflow valve of each of the one-way relief valves is connected to the one-way flow inlet of their respective one-way valves.

[0019] As a preferred embodiment of the above-mentioned shifting system, the shifting oil inlet of the hydraulic shifting assembly is connected to the pipeline that connects the oil outlet of the second pump with the one-way flow inlet of the one-way valve of the two one-way relief valves.

[0020] And / or, the shifting system further includes a second overflow valve, the pilot port and overflow inlet of the second overflow valve being connected to a pipeline that connects the outlet of the second pump to the one-way flow inlet of the one-way valve of the two one-way overflow valves, and the overflow outlet of the second overflow valve being connected to the oil tank.

[0021] As a preferred embodiment of the above-mentioned shifting system, the shifting system further includes a second directional control valve, which enables one of the two first connecting ports for hydraulic oil outflow to remain connected to the oil tank, and enables both first connecting ports to be disconnected from the oil tank.

[0022] Agricultural machinery, including the aforementioned gear shifting system.

[0023] As a preferred embodiment of the aforementioned agricultural machinery, the agricultural machinery is a harvester, and the driving component is the engine of the harvester.

[0024] The beneficial effects of this utility model are:

[0025] This utility model provides a gear shifting system and agricultural machinery. During normal operation of the agricultural machinery, the switch control valve remains in the first position, and the two second connecting ports of the switch control valve remain disconnected. The first pump and the hydraulic motor form a series circuit. The drive component drives the drive shaft of the first pump to rotate around its own central axis, causing pressure to build up in the series circuit. This pressure drives the output shaft of the hydraulic motor to rotate around its own central axis. The output shaft of the hydraulic motor is connected to the input shaft of the gearbox, thereby driving the input shaft of the gearbox to rotate around its own central axis. The gearbox drives the axle, causing the agricultural machinery to move. During this process, the drive component synchronously drives the second pump, causing the second pump to synchronously replenish oil to the series circuit formed by the first pump and the hydraulic motor. This prevents the amount of hydraulic oil in the series circuit from decreasing due to leakage from the hydraulic motor and / or the first pump, thus improving the working stability and reliability of the gear shifting system.

[0026] When agricultural machinery stops and shifts gears, the switch control valve remains in the second position, with its two second ports connected to each other. The switch control valve, hydraulic motor, and first pump form a parallel circuit. The two first ports of the hydraulic motor are directly connected through the switch control valve, keeping the hydraulic motor in a floating, stationary state. The gearbox is also stationary. Understandably, applying a small amount of hydraulic pressure to the shift fork of the hydraulic shift assembly at this time is sufficient to push the shift fork and achieve gear shifting. This effectively improves the success rate of fast and efficient gear shifting in agricultural machinery on uphill and / or uneven road surfaces, and also effectively extends the service life of the shift gear ring. By setting a drive component, the drive shaft of the second pump can be synchronously driven to rotate around its own central axis. During this process, the second pump can simultaneously replenish oil to the parallel circuit formed by the switch control valve, hydraulic motor, and first pump to improve the working stability and reliability of the shifting system, and simultaneously deliver hydraulic oil to the shift inlet of the hydraulic shift assembly to drive gear shifting, thereby improving the coordination of the shifting system. Compared with existing technologies, this effectively reduces the number of pumps required.

[0027] Secondly, compared with the existing two-position three-way valve, the switching control valve simplifies the structure and reduces costs. Furthermore, when the switching control valve is in the first position, the amount of hydraulic oil leaking from the high-pressure side to the low-pressure side of the two second connecting ports is small, resulting in good reliability of the switching control valve and further improving the working stability and reliability of the shifting system.

[0028] Therefore, the shifting system has a simple structure, few parts, and low production cost. Secondly, the shifting system has good coordination when shifting gears while parked, and can quickly and efficiently shift gears even on uphill slopes and / or uneven roads, effectively improving the service life of the shift gear ring. Furthermore, the system can synchronously replenish oil to the circuit formed by the hydraulic motor and the first pump throughout the entire operation, resulting in good working stability and reliability. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the shifting system provided in a specific embodiment of this utility model;

[0030] Figure 2 This is a partial schematic diagram of the shifting system provided in a specific embodiment of this utility model;

[0031] Figure 3 This is a schematic diagram of the hydraulic shifting assembly provided in a specific embodiment of this utility model.

[0032] In the picture:

[0033] 1. First pump; 2. Hydraulic motor;

[0034] 3. Hydraulic shift assembly; 31. First shift fork; 32. Second shift fork; 33. First shift cylinder; 34. Second shift cylinder; 35. Third shift cylinder; 36. Fourth shift cylinder; 37. First gear control valve; 38. Second gear control valve; 39. Third gear control valve; 40. Neutral gear control valve;

[0035] 4. Switch control valve; 5. Second pump; 6. Oil tank;

[0036] 71. First hydraulic cylinder; 711. First cylinder body; 712. First piston; 713. First spring;

[0037] 72. Second hydraulic cylinder; 721. Second cylinder body; 722. Second piston; 723. Second spring;

[0038] 73. First directional control valve; 731. First valve core; 732. First valve sleeve;

[0039] 74. Proportional valve; 75. Feedback rod; 76. Sealing head;

[0040] 8. One-way relief valve; 81. One-way valve; 82. First relief valve;

[0041] 9. Second relief valve; 10. Second directional control valve; 11. Filter; 12. Heat exchanger. Detailed Implementation

[0042] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.

[0043] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction 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.

[0044] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.

[0045] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.

[0046] This utility model provides a gear shifting system, such as Figure 1-3As shown, the shifting system includes a drive unit, a first pump 1, a hydraulic motor 2, a gearbox, a hydraulic shift assembly 3, a switch control valve 4, and a second pump 5. The output shaft of the drive unit is connected to the drive shaft of the first pump 1, and the drive shaft of the hydraulic motor 2 is connected to the input shaft of the gearbox. The two first ports of the hydraulic motor 2 are connected to the two oil ports of the first pump 1. The switch control valve 4, the hydraulic motor 2, and the first pump 1 are all connected in parallel. The two second ports of the switch control valve 4 are connected to the two oil ports of the first pump 1. When the switch control valve 4 is in the first position, the two second ports are disconnected; when the switch control valve 4 is in the second position, the two second ports are connected. The output shaft of the drive unit is also connected to the drive shaft of the second pump 5. The oil inlet of the second pump 5 is connected to the oil tank 6, and the oil outlet of the second pump 5 is connected to the circuit formed by the hydraulic motor 2 and the first pump 1 to replenish the circuit. The oil outlet of the second pump 5 is also connected to the shift inlet of the hydraulic shift assembly 3 to drive the shifting, thereby enabling the gearbox to shift gears.

[0047] Taking the application of this shifting system to a harvester as an example, during normal operation, the switch control valve 4 remains in the first position, and the two second connecting ports of the switch control valve 4 remain disconnected. The first pump 1 and the hydraulic motor 2 form a series circuit. The drive component drives the drive shaft of the first pump 1 to rotate around its own central axis, causing pressure to build up in the series circuit. This pressure drives the drive shaft of the hydraulic motor 2 to rotate around its own central axis. The drive shaft of the hydraulic motor 2 is connected to the input shaft of the gearbox, thereby driving the input shaft of the gearbox to rotate around its own central axis. The gearbox drives the axle, causing the harvester to move. During this process, the drive component synchronously drives the second pump 5, causing the second pump 5 to synchronously replenish oil to the series circuit formed by the first pump 1 and the hydraulic motor 2. This prevents the amount of hydraulic oil in the series circuit from decreasing due to leakage from the hydraulic motor 2 and / or the first pump 1, thereby improving the working stability and reliability of the shifting system.

[0048] When the harvester stops and shifts gears, the switch control valve 4 remains in the second position, and the two second connecting ports of the switch control valve 4 remain connected to each other. The switch control valve 4, hydraulic motor 2, and first pump 1 form a parallel circuit. The two first connecting ports of hydraulic motor 2 are directly connected through the switch control valve 4, making hydraulic motor 2 in a floating and stationary state. The gearbox is also in a stationary state. Understandably, at this time, applying a very small amount of hydraulic pressure to the shift fork of the hydraulic shift assembly 3 is sufficient to push the shift fork to achieve gear shifting, which can effectively improve the harvester's speed in scenarios such as uphill and / or potholed roads. The system boasts a high success rate for gear shifting and effectively extends the service life of the shift gear ring. By setting up a driving component, the second pump 5's drive shaft can be synchronously driven to rotate around its own central axis. During this process, the second pump 5 can simultaneously replenish oil to the parallel circuit formed by the switch control valve 4, hydraulic motor 2, and first pump 1, thereby improving the working stability and reliability of the shifting system. It can also simultaneously deliver hydraulic oil to the shift inlet of the hydraulic shift assembly 3 to drive gear shifting, thus improving the coordination of the shifting system. Compared with the prior art, it effectively reduces the number of pumps required.

[0049] Secondly, compared with the two-position three-way valve in the prior art, the switching control valve 4 can simplify the structure and reduce the cost. Secondly, when the switching control valve 4 is in the first position, the amount of hydraulic oil leaking from the high-pressure side to the low-pressure side of the two second connecting ports is small, and the switching control valve 4 has good reliability, thereby further improving the working stability and reliability of the shifting system.

[0050] Therefore, the shifting system has a simple structure, few parts, and low production cost; secondly, the shifting system has good coordination when shifting gears while parked, and can quickly and efficiently shift gears even on uphill and / or bumpy roads, and can effectively improve the service life of the shift gear ring; thirdly, it can synchronously replenish oil to the circuit formed by the hydraulic motor 2 and the first pump 1 throughout the entire operation, and the shifting system has good working stability and reliability.

[0051] Specifically, in this embodiment, the switch control valve 4 is a two-position, two-way solenoid switch valve. This allows for easy adjustment of the switch control valve 4 to maintain either the first or second position.

[0052] Specifically, in this embodiment, Figure 1 The left position of the switch control valve 4 is the first position of the switch control valve 4; Figure 1 The right position of the switch control valve 4 is the second position of the switch control valve 4. That is, when the switch control valve 4 is in the left position, the two second connection ports are disconnected from each other; when the switch control valve 4 is in the right position, the two second connection ports are connected to each other.

[0053] Specifically, in this embodiment, the drive shafts of the first pump 1 and the second pump 5 are exemplarily configured to be coaxially fixed. In other embodiments, the drive shafts of the first pump 1 and the second pump 5 may also be connected via a transmission assembly or the like.

[0054] Specifically, in this embodiment, as Figure 1 and Figure 2 As shown, the first pump 1 is an axial piston variable displacement pump. The second pump 5 is a one-way pump. The hydraulic motor 2 is a fixed displacement motor. In other embodiments, the hydraulic motor 2 may also be a variable displacement motor.

[0055] The shifting system also includes a displacement regulating assembly. The outlet of the second pump 5 is connected to the displacement regulating inlet of the displacement regulating assembly, which is used to drive the displacement regulating assembly to adjust the displacement of the first pump 1. It can be understood that the second pump 5 can both replenish oil to the circuit formed by the hydraulic motor 2 and the first pump 1, and deliver hydraulic oil to the shifting inlet of the hydraulic shifting assembly 3 to drive shifting, and also regulate the displacement of the first pump 1. The integrated functions of the second pump 5 further simplify the structure of the shifting system while still achieving the goal of regulating the displacement of the first pump 1.

[0056] Specifically, such as Figure 1 and Figure 2 As shown, the displacement adjustment assembly includes a first hydraulic cylinder 71, which includes a first cylinder body 711 and a first piston 712 slidably disposed within the first cylinder body 711. The first piston 712 divides the chamber of the first cylinder body 711 into two non-communicating first chambers. The first piston 712 is connected to the swashplate of the first pump 1 to drive the swashplate to rotate. The two first chambers are configured such that one can selectively connect to the oil outlet of the second pump 5 and the other to the oil tank 6, or selectively both can be connected to the oil tank 6. With this configuration, the second pump 5 inputs hydraulic oil into one of its first chambers and connects the other first chamber to the oil tank 6, thereby driving the first piston 712 to slide relative to the first cylinder body 711. During the sliding of the first piston 712 relative to the first cylinder body 711, it drives the swashplate to rotate, thereby adjusting the displacement of the first pump 1.

[0057] More specifically, such as Figure 1 and Figure 2 As shown, the first cylinder 71 also includes two first springs 713, which are located in the two first chambers respectively. Along the sliding direction of the first piston 712, one end of the first spring 713 elastically presses against the first cylinder body 711, and the other end of the first spring 713 elastically presses against the first piston 712. This allows the first piston 712 to return to the middle position in the chamber of the first cylinder body 711 under the action of the two first springs 713.

[0058] Specifically, such as Figure 1 and Figure 1 As shown, the displacement regulating assembly also includes a second cylinder 72 and a first directional control valve 73. The second piston 722 of the second cylinder 72 is connected to the first valve core 731 of the first directional control valve 73, and the first valve sleeve 732 of the first directional control valve 73 is also fixedly connected to the first piston 712. The second piston 722 can drive the first valve core 731 to slide relative to the first valve sleeve 732, so that the oil outlet of the second pump 5 communicates with one of the first chambers, and the other first chamber communicates with the oil tank 6. The first piston 712 can drive the first valve sleeve 732 to slide in the same direction relative to the first valve core 731, so that both first chambers communicate with the oil tank 6. Specifically, the first piston 712 is rotatably connected to the swashplate through a feedback rod 75, and is fixedly connected to the first valve sleeve 732 of the first directional control valve 73 through the feedback rod 75.

[0059] More specifically, such as Figure 1 and Figure 2 As shown, the two first chambers are the first sub-chamber and the second sub-chamber, respectively; the first directional control valve 73 is a three-position four-way valve; when the first directional control valve 73 is in the first position, the first sub-chamber is connected to the oil outlet of the second pump 5, and the second sub-chamber is connected to the oil tank 6; when the first directional control valve 73 is in the second position, the second sub-chamber is connected to the oil outlet of the second pump 5, and the first sub-chamber is connected to the oil tank 6; when the first directional control valve 73 is in the third position, both the first sub-chamber and the second sub-chamber are connected to the oil tank 6.

[0060] To be more specific, Figure 1 and Figure 2 The right position of the first directional control valve 73 is the first position of the first directional control valve 73; Figure 1 and Figure 2 The left position of the first directional control valve 73 is the second position of the first directional control valve 73; Figure 1 and Figure 2 The intermediate position of the first directional control valve 73 is the third position of the first directional control valve 73.

[0061] More specifically, such as Figure 2 As shown, the first valve core 731 of the three-position four-way valve has ports P1, T1, A1, and B1. Port P1 is connected to the oil outlet of the second pump 5, port T1 is connected to the oil tank 6, port A1 is connected to the first sub-chamber, and port B1 is connected to the second sub-chamber. When the first directional control valve 73 is in the first position, ports P1 and A1 are connected, and ports B1 and T1 are connected. When the first directional control valve 73 is in the second position, ports P1 and B1 are connected, and ports A1 and T1 are connected. When the first directional control valve 73 is in the third position, port P1 is blocked, and ports A1 and B1 are both connected to port T1.

[0062] This configuration allows for selective connection of one of the two first chambers to the oil outlet of the second pump 5, and the other to the oil tank 6; or, selectively, both first chambers to be connected to the oil tank 6. Specifically, when one of the two first chambers is connected to the oil outlet of the second pump 5, and the other to the oil tank 6, the swashplate can be driven to rotate forward or backward; when both first chambers are connected to the oil tank 6, the hydraulic oil in both first chambers drains into the oil tank 6, and the first piston 712 returns to its central position within the chamber of the first cylinder 711 under the action of the two first springs 713.

[0063] Specifically, such as Figure 1 and Figure 2 As shown, the displacement regulating assembly also includes two proportional valves 74. The second piston 722 is slidably disposed within the second cylinder body 721 of the second cylinder 72, dividing the chamber of the second cylinder body 721 into two non-communicating second chambers. The oil inlets of both proportional valves 74 are connected to the oil outlet of the second pump 5, and the oil outlets of the two proportional valves 74 are connected to the two second chambers one-to-one. This allows for the control of supplying different amounts of hydraulic oil to the two second chambers, thereby controlling the forward or reverse rotation of the swashplate.

[0064] More specifically, such as Figure 1 and Figure 2 As shown, the second cylinder 72 also includes two second springs 723, which are located correspondingly in the two second chambers. Along the sliding direction of the second piston 722, one end of the second spring 723 elastically presses against the second cylinder body 721, and the other end of the second spring 723 elastically presses against the second piston 722. This allows the second piston 722 to return to the middle position within the chamber of the second cylinder body 721 under the action of the two second springs 723. When the second piston 722 is in the middle position within the chamber of the second cylinder body 721, the first piston 712 is in the middle position within the chamber of the first cylinder body 711.

[0065] Optionally, the second cylinder block 721 is also provided with two test ports, which are connected to the two second chambers one-to-one. For example... Figure 1 and Figure 2 As shown, the shifting system includes two sealing heads 76, which are correspondingly sealed to two test ports. This allows the hydraulic oil pressure in the two second chambers to be detected through the two test ports.

[0066] As an alternative, the displacement adjustment assembly includes a hydraulic cylinder, the piston of which is connected to the swashplate to drive the swashplate to rotate. It is understood that the specific structure of the displacement adjustment assembly is not limited, as long as it can drive the swashplate to rotate forward and reverse to adjust the displacement of the first pump 1.

[0067] Among them, such as Figure 1As shown, the shifting system also includes two one-way relief valves 8, each comprising a one-way valve 81 and a first relief valve 82. The one-way flow inlets of the one-way valves 81 of both one-way relief valves 8 are connected to the oil outlet of the second pump 5, and the one-way flow outlets of the one-way valves 81 of both one-way relief valves 8 are correspondingly connected to the two oil ports of the first pump 1. The pilot oil port and overflow inlet of the first relief valve 82 of each one-way relief valve 8 are connected to the one-way flow outlet of its respective one-way valve 81, and the overflow outlet of the first relief valve 82 of each one-way relief valve 8 is connected to the one-way flow inlet of its respective one-way valve 81. This ensures a stable replenishment oil pressure for supplying oil to the circuit formed by the hydraulic motor 2 and the first pump 1.

[0068] Optionally, such as Figure 1 As shown, the shift inlet of the hydraulic shift assembly 3 is connected to the pipeline that connects the outlet of the second pump 5 to the one-way flow inlet of the one-way valve 81 of the two one-way relief valves 8. This arrangement results in a small connection distance between the outlet of the second pump 5 and the shift inlet of the hydraulic shift assembly 3, which can further improve the efficiency of driving the hydraulic shift assembly 3 to shift gears.

[0069] Optionally, such as Figure 1 As shown, the shifting system also includes a second relief valve 9. The oil inlet and overflow inlet of the second relief valve 9 are both connected to the pipeline connecting the oil outlet of the second pump 5 to the one-way flow inlet of the one-way valve 81 of the two one-way relief valves 8. The overflow outlet of the second relief valve 9 is connected to the oil tank 6. This ensures a stable oil pressure for the hydraulic oil supplied to the two one-way relief valves 8.

[0070] Specifically, such as Figure 1 and Figure 2 As shown, in this embodiment, the inlets of the two proportional valves 74 and the P1 port of the first directional control valve 73 are all connected to the pipeline that connects to the one-way flow inlet of the one-way valve 81 of the two one-way relief valves 8. This ensures that the second relief valve 9 can also stably supply hydraulic oil pressure to the first directional control valve 73 and the two proportional valves 74.

[0071] Optionally, such as Figure 1 As shown, a filter 11 is installed on the pipeline connecting the oil outlet of the second pump 5 and the inlet of the second relief valve 9. The filter 11 is used to filter the oil. This reduces the risk of clogging the second relief valve 9 and / or the displacement regulating assembly and / or the two one-way relief valves 8, etc.

[0072] Among them, such as Figure 1As shown, the shifting system also includes a second directional control valve 10. The second directional control valve 10 can connect one of the two first connecting ports (for hydraulic oil outflow) to the oil tank 6, and can also disconnect both first connecting ports from the oil tank 6. Specifically, when the switch control valve 4 is in the first position, the second directional control valve 10 connects one of the two first connecting ports (for hydraulic oil outflow) to the oil tank 6; when the switch control valve 4 is in the second position, the second directional control valve 10 disconnects both first connecting ports from the oil tank 6. It can be understood that when the switch control valve 4 is in the first position, the hydraulic oil flowing out from one of the two first connecting ports is divided into two parts, namely a first part and a second part. The first part flows to the oil tank 6 through the second directional control valve 10, and the second part flows in the circuit formed by the hydraulic motor 2 and the first pump 1. Then, the second pump 5 synchronously replenishes oil to the circuit formed by the hydraulic motor 2 and the first pump 1, so that the temperature of the circuit formed by the hydraulic motor 2 and the first pump 1 can be effectively regulated by replenishing oil, thereby further improving the stability and reliability of the shifting system.

[0073] Specifically, in this embodiment, such as Figure 1 As shown, the second directional control valve 10 is a three-position three-way valve. In this embodiment, Figure 1 The upper position of the second directional control valve 10 is the first position of the second directional control valve 10; Figure 1 The lower position of the second directional control valve 10 is the second position of the second directional control valve 10; Figure 1 The middle position of the second directional control valve 10 is the third position of the second directional control valve 10.

[0074] In this embodiment, as Figure 1 As shown, the three-position three-way valve has ports P2, T2, and A2. Port P2 is connected to a first connecting port located above, port A2 is connected to a second connecting port located below, and port T2 is connected to the oil tank 6. When the second directional control valve 10 is in the first position, port P2 is blocked, and ports A2 and T2 are connected. When the second directional control valve 10 is in the second position, ports P2 and T2 are connected, and port A2 is blocked. When the second directional control valve 10 is in the third position, ports P2, T2, and A2 are not connected to each other. Furthermore, in this embodiment, the second directional control valve 10 also has two pilot ports, and the two pilot ports of the second directional control valve 10 are connected to the two first connecting ports one-to-one.

[0075] Taking the hydraulic oil flowing through the hydraulic motor 2 as an example, which flows in through the upper first connection port and out through the lower first connection port, when the hydraulic oil is pumped into the upper first connection port, a portion of the hydraulic oil simultaneously enters the upper pilot port of the second directional control valve 10, driving the second valve core of the second directional control valve 10 to move relative to the second valve sleeve of the second directional control valve 10, so that the second directional control valve 10 is in the first working position. Thus, the hydraulic oil flowing out of the lower first connection port is divided into two parts, namely the first part and the second part. The first part flows through the A2 port and the T2 port and flows to the oil tank 6. The second part flows in the circuit formed by the hydraulic motor 2 and the first pump 1. During this process, the second pump 5 simultaneously replenishes oil to the circuit formed by the hydraulic motor 2 and the first pump 1, so that the temperature of the circuit formed by the hydraulic motor 2 and the first pump 1 can be effectively regulated by replenishing oil, so as to further improve the stability and reliability of the shifting system.

[0076] As an alternative, the second directional control valve 10 can also include two flow valves. The inlets of the two flow valves are connected to the two first connecting ports one-to-one, and the outlets of both flow valves are connected to the oil tank 6. When the switch control valve 4 is in the first position, the opening of the flow valve corresponding to the inflow of hydraulic oil in the two first connecting ports is adjusted to zero, and the opening of the flow valve corresponding to the outflow of hydraulic oil in the two first connecting ports is adjusted to the expected opening. This allows a portion of the hydraulic oil in the circuit formed by the hydraulic motor 2 and the first pump 1 to flow out to the oil tank 6, thereby achieving the purpose of temperature regulation of the circuit formed by the hydraulic motor 2 and the first pump 1 through oil replenishment.

[0077] Specifically, such as Figure 1 and Figure 2 As shown, the shifting system also includes a heat exchanger 12, whose inlet and outlet are both connected to the oil tank 6. Furthermore, a delivery pump is installed on the pipeline connecting the inlet of the heat exchanger 12 to the oil tank 6; and / or, a delivery pump is installed on the pipeline connecting the outlet of the heat exchanger 12 to the oil tank 6. The drive shaft of the delivery pump is connected to the output shaft of the drive unit, or the drive shaft of the delivery pump is driven by an independently installed drive motor, etc.

[0078] For example, a hydraulic shift assembly 3 includes two shift forks. Figure 3 As shown, the two shift forks are the first shift fork 31 and the second shift fork 32, respectively. The first shift fork 31 is the shift fork for first and second gear, and the second shift fork 32 is the shift fork for third gear.

[0079] Specifically, such as Figure 3As shown, the hydraulic shift assembly 3 also includes a first shift cylinder 33 and a second shift cylinder 34 disposed on both axial sides of the first shift fork 31, and a third shift cylinder 35 and a fourth shift cylinder 36 cooperating on both axial sides of the second shift fork 32. The pistons of the first shift cylinder 33 and the second shift cylinder 34 are both connected to the first shift fork 31 and are used to drive the first shift fork 31 to move axially. The pistons of the third shift cylinder 35 and the fourth shift cylinder 36 are both connected to the second shift fork 32 and are used to drive the second shift fork 32 to move axially.

[0080] Specifically, such as Figure 3 As shown, the hydraulic shift assembly 3 also includes a first-gear control valve 37, a second-gear control valve 38, and a third-gear control valve 39. The first-gear control valve 37, the second-gear control valve 38, and the third-gear control valve 39 are all first-position two-way three-way valves. Each first-position two-way three-way valve has a P3 port, a T3 port, and an A3 port. When the first-position two-way three-way valve is in the first operating position, the P3 port and the A3 port are connected, and the T3 port is blocked. When the first-position two-way three-way valve is in the second operating position, the P3 port is blocked, and the T3 port and the A3 port are connected, with the T3 port also connected to the oil tank 6.

[0081] In this embodiment, Figure 3 The right position of the first two-position three-way valve is the first position of the first two-position three-way valve. Figure 3 The left position of the first two-position three-way valve is the second position of the first two-position three-way valve.

[0082] Specifically, such as Figure 3 As shown, the hydraulic shift assembly 3 also includes a neutral control valve 40. The neutral control valve 40 is a second two-position three-way valve, which has a P4 port, a T4 port, and an A4 port. The P4 port is connected to the oil outlet of the second pump 5, and the T4 port is connected to the oil tank 6. When the second two-position three-way valve is in the first position, the T4 port and the A4 port are connected, and the P4 port is blocked. When the first two-position three-way valve is in the second position, the P4 port and the A4 port are connected, and the T4 port is blocked.

[0083] In this embodiment, Figure 3 The right position of the second two-position three-way valve is the first position of the second two-position three-way valve, and the left position of the second two-position three-way valve is the second position of the second two-position three-way valve.

[0084] More specifically, such as Figure 3 As shown, the P3 port of the first gear control valve 37, the P3 port of the second gear control valve 38, the P3 port of the third gear control valve 39, and the chamber of the fourth shift cylinder 36 are all connected to the A4 port; the A3 port of the first gear control valve 37 is connected to the chamber of the first shift cylinder 33, the A3 port of the second gear control valve 38 is connected to the chamber of the second shift cylinder 34, and the A3 port of the third gear control valve 39 is connected to the chamber of the third shift cylinder 35.

[0085] When in neutral, the neutral control valve 40 is in the second position, and the first gear control valve 37, second gear control valve 38 and third gear control valve 39 are all in the first position. Hydraulic oil is introduced into port P4 so that the first shift fork 31 and the second shift fork 32 are both in the neutral position.

[0086] When in first gear, the neutral control valve 40 is in the second position, the first gear control valve 37 is in the second position, and the second gear control valve 38 and the third gear control valve 39 are both in the first position, causing the first shift fork 31 to move to the left.

[0087] When shifting to second gear, the neutral control valve 40 is in the second position, the second gear control valve 38 is in the second position, and the first gear control valve 37 and the third gear control valve 39 are both in the first position, causing the first shift fork 31 to move to the right.

[0088] When the gear is in third gear, the neutral control valve 40 is in the second position, the third gear control valve 39 is in the second position, and the first gear control valve 37 and the second gear control valve 38 are both in the first position, causing the second shift fork 32 to move to the right.

[0089] This utility model also provides agricultural machinery, including the aforementioned gear shifting system. By employing this gear shifting system, good coordination during gear shifting while stationary is achieved, and gear shifting can be completed quickly and efficiently even on uphill slopes and / or uneven road surfaces, effectively extending the service life of the gear shift ring. Furthermore, throughout the entire operation, oil can be synchronously replenished to the circuit formed by the hydraulic motor 2 and the first pump 1, resulting in good working stability and reliability of the gear shifting system. Additionally, the temperature of the circuit formed by the hydraulic motor 2 and the first pump 1 can be regulated through oil replenishment, further enhancing the stability and reliability of the gear shifting system.

[0090] Specifically, in this embodiment, an agricultural machine is used as an example, and the driving component is the engine of the harvester.

[0091] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.

Claims

1. A gear shifting system, comprising a drive component, a first pump (1), a hydraulic motor (2), a gearbox, and a hydraulic shifting assembly (3), wherein the output shaft of the drive component is drivenly connected to the drive shaft of the first pump (1); the output shaft of the hydraulic motor (2) is drivenly connected to the input shaft of the gearbox; and the two first communication ports of the hydraulic motor (2) are connected one-to-one with the two oil ports of the first pump (1); characterized in that, The shifting system also includes: The switch control valve (4), the hydraulic motor (2) and the first pump (1) are all connected in parallel. The two second ports of the switch control valve (4) are connected to the two oil ports of the first pump (1) in a one-to-one correspondence. When the switch control valve (4) is in the first position, the two second ports are disconnected from each other. When the switch control valve (4) is in the second position, the two second ports are connected to each other. The output shaft of the second pump (5) is also connected to the drive shaft of the second pump (5). The oil inlet of the second pump (5) is connected to the oil tank (6). The oil outlet of the second pump (5) is connected to the circuit formed by the hydraulic motor (2) and the first pump (1) to replenish the circuit. The oil outlet of the second pump (5) is also connected to the shift oil inlet of the hydraulic shift assembly (3) for driving shifting, so that the gearbox shifts.

2. The shifting system according to claim 1, characterized in that, The shifting system also includes a displacement adjustment assembly, and the oil outlet of the second pump (5) is connected to the displacement adjustment inlet of the displacement adjustment assembly, for driving the displacement adjustment assembly to adjust the displacement of the first pump (1).

3. The shifting system according to claim 2, characterized in that, The first pump (1) is a swashplate piston pump; the displacement regulating assembly includes a first cylinder (71), the first cylinder (71) includes a first cylinder body (711) and a first piston (712) slidably disposed in the first cylinder body (711), the first piston (712) divides the chamber of the first cylinder body (711) into two non-communicating first chambers; the first piston (712) is connected to the swashplate of the first pump (1) to drive the swashplate to rotate; The two first chambers are configured to selectively connect one to the oil outlet of the second pump (5) and the other to the oil tank (6), or selectively connect both to the oil tank (6).

4. The shifting system according to claim 3, characterized in that, The displacement regulating assembly also includes a second cylinder (72) and a first directional control valve (73). The second piston (722) of the second cylinder (72) is connected to the first valve core (731) of the first directional control valve (73). The first valve sleeve (732) of the first directional control valve (73) is also fixedly connected to the first piston (712). The second piston (722) can drive the first valve core (731) to slide relative to the first valve sleeve (732) so that the oil outlet of the second pump (5) is connected to one of the first chambers and the other first chamber is connected to the oil tank (6); the first piston (712) can drive the first valve sleeve (732) to slide in the same direction relative to the first valve core (731) so that both first chambers are connected to the oil tank (6).

5. The shifting system according to claim 4, characterized in that, The displacement regulating assembly also includes two proportional valves (74), and the second piston (722) is slidably disposed in the second cylinder body (721) of the second cylinder (72) and divides the chamber of the second cylinder body (721) into two non-communicating second chambers; The oil inlets of both proportional valves (74) are connected to the oil outlet of the second pump (5), and the oil outlets of the two proportional valves (74) are connected to the two second chambers in a one-to-one correspondence.

6. The shifting system according to any one of claims 1-5, characterized in that, The shifting system also includes two one-way relief valves (8), each of which includes a one-way valve (81) and a first relief valve (82). The one-way flow inlets of the one-way valves (81) of the two one-way relief valves (8) are connected to the oil outlet of the second pump (5), and the one-way flow outlets of the one-way valves (81) of the two one-way relief valves (8) are connected to the two oil ports of the first pump (1) in a one-to-one correspondence. The pilot port and overflow inlet of the first overflow valve (82) of each of the one-way overflow valves (8) are connected to the one-way flow outlet of their respective one-way valves (81), and the overflow outlet of the first overflow valve (82) of each of the one-way overflow valves (8) is connected to the one-way flow inlet of their respective one-way valves (81).

7. The shifting system according to claim 6, characterized in that, The shift inlet of the hydraulic shift assembly (3) is connected to the pipeline that connects the outlet of the second pump (5) with the one-way flow inlet of the one-way valve (81) of the two one-way relief valves (8); And / or, the shifting system further includes a second overflow valve (9), the pilot port and overflow inlet of the second overflow valve (9) are both connected to the pipeline connecting the oil outlet of the second pump (5) and the one-way flow inlet of the one-way valve (81) of the two one-way overflow valves (8), and the overflow outlet of the second overflow valve (9) is connected to the oil tank (6).

8. The shifting system according to any one of claims 1-5, characterized in that, The shifting system also includes a second directional control valve (10), which enables one of the two first communication ports for hydraulic oil to flow out to be connected to the oil tank (6), and enables both first communication ports to be disconnected from the oil tank (6).

9. Agricultural machinery, characterized in that, Includes the shifting system according to any one of claims 1-8.

10. The agricultural machinery according to claim 9, characterized in that, The agricultural machinery is a harvester, and the driving component is the engine of the harvester.

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