Agricultural machinery gearbox

Abstract

The utility model belongs to the technical field of agricultural machinery, and relates to an agricultural machinery gearbox which comprises an input shaft, a driving transmission mechanism, a steering transmission mechanism and a planetary differential mechanism, a first hydrostatic transmission device and a second hydrostatic transmission device are arranged outside a gearbox body of the gearbox in parallel, and a main input gear is arranged on the input shaft. A first hydrostatic transmission input gear and a second hydrostatic transmission input gear are meshed with the two sides of the main input gear respectively, an input shaft of the first hydrostatic transmission device is in spline connection with the first hydrostatic transmission input gear, and an output shaft of the first hydrostatic transmission device is in spline connection with the driving input gear. An input shaft of the second hydrostatic transmission device is in spline connection with the second hydrostatic transmission input gear, and an output shaft of the second hydrostatic transmission device is in spline connection with the steering input gear. The agricultural machinery gearbox has the advantages of being compact in structure, reasonable in layout, fast in output response and the like.

Description

Technical Field

[0001] This utility model belongs to the technical field of agricultural machinery, and relates to an agricultural machinery gearbox. Background Technology

[0002] Conventional agricultural machinery gearboxes use mechanical gearboxes, which are complex in structure, have numerous internal gears, and are inconvenient for shifting and steering. As the requirements for agricultural machinery gearboxes become increasingly demanding, these mechanical gearboxes are no longer sufficient. Replacing traditional structures with hydrostatic transmissions (HST) has become a trend. HST is a continuously variable transmission (CVT) based on the principle of hydrostatics, mainly composed of a variable displacement piston pump, a fixed displacement piston motor, a cycloidal replenishing pump, and hydraulic control valves, forming a closed loop. The engine drives the variable displacement piston pump to rotate. By changing the tilt angle of the variable displacement pump's variable disc using a control handle, the pump's displacement and direction are altered, thus changing the flow and pressure of the output hydraulic oil. The hydraulic oil drives the fixed displacement piston motor, causing it to output different speeds and directions. Because the angle of the variable displacement piston pump's variable disc can be continuously adjusted, the output speed of the piston motor also changes continuously, thereby achieving continuously variable transmission for the traveling mechanism to meet the requirements of different working conditions. Using an HST transmission system simplifies the transmission structure, reduces the number of gears, and makes traveling control and steering more convenient.

[0003] Chinese utility model patent CN201376594Y (publication date: 2010-01-06) discloses a vehicle hydraulic-mechanical integrated transmission device, comprising a main transmission section, a secondary transmission section, a steering differential section, and a wheel-side transmission section. The main transmission section includes an input shaft and a first hydrostatic transmission device. The steering differential section includes a second hydrostatic transmission device and left and right planetary differential devices. A portion of the power from the engine is transmitted to the wheel-side transmission section via the input shaft, the first hydrostatic transmission device, the secondary transmission section, and the left and right planetary differential devices; the other portion is transmitted to the wheel-side transmission section via the input shaft, the second hydrostatic transmission device, and the left and right planetary differential devices. The second hydrostatic transmission device transmits power only when the tracked vehicle is steering.

[0004] The aforementioned gearbox is powered by two hydrostatic transmission devices. The main input shaft is connected to the travel HST, and a gear on the main input shaft distributes power to the steering HST. This layout increases the required axial dimension of the gearbox, and the gear design within the gearbox is not simple enough. Utility Model Content

[0005] This utility model addresses the shortcomings of existing technologies by providing an agricultural machinery gearbox, which has advantages such as compact structure, reasonable layout, and fast output response.

[0006] To solve the above-mentioned technical problems, the objective of this utility model is achieved through the following technical solution:

[0007] An agricultural machinery gearbox includes an input shaft, a drive transmission mechanism, a steering transmission mechanism, and a planetary differential mechanism. The input shaft is connected to a power unit. The drive transmission mechanism is connected to the intermediate gear of the planetary differential mechanism. The steering transmission mechanism is connected to the differential gear of the planetary differential mechanism. A first hydrostatic transmission device and a second hydrostatic transmission device are arranged parallel to each other outside the gearbox housing. A main input gear is provided on the input shaft. A first hydrostatic transmission input gear and a second hydrostatic transmission input gear are respectively meshed on both sides of the main input gear. The input shaft of the first hydrostatic transmission device is splinedly connected to the first hydrostatic transmission input gear, and its output shaft is splinedly connected to the drive input gear. The input shaft of the second hydrostatic transmission device is splinedly connected to the second hydrostatic transmission input gear, and its output shaft is splinedly connected to the steering input gear.

[0008] In the aforementioned agricultural machinery gearbox, the drive transmission mechanism includes a drive input gear, a shift gear set, and a transmission gear set. The shift gear set includes a shift input gear, a first gear and a second gear loosely fitted on a gear shaft. The first gear and the second gear are selectively connected to the gear shaft. The transmission gear set includes a primary transmission gear and a secondary transmission gear. The primary transmission gear meshes with the first gear and an intermediate gear, and the secondary transmission gear meshes with the second gear.

[0009] In the aforementioned agricultural machinery gearbox, a synchronizer driven by a shift fork is slidably mounted on the gear shaft of the shift gear set. The synchronizer changes the transmission state between the gear shaft and the first gear and the second gear by axial movement. The shift fork is driven by a shift rocker arm that extends to the outside of the gearbox. Furthermore, the connection structure between the shift fork and the synchronizer is as follows: an annular groove is provided on the outer periphery of the synchronizer's gear sleeve, and the end of the shift fork is embedded in the annular groove to drive the synchronizer to move axially.

[0010] In the above-mentioned agricultural machinery gearbox, a braking mechanism for braking its gear shaft is provided on one side of the gear set; the braking mechanism is a hydraulic brake or a friction brake.

[0011] In the aforementioned agricultural machinery gearbox, the steering transmission mechanism includes a steering input gear, a double gear, a reverse gear set, and an idler gear. The two gears of the double gear mesh with the steering input gear and the gear in the middle of the reverse gear set, respectively. The gear on the left side of the reverse gear set meshes with the left differential gear, and the gear on the right side meshes with the idler gear. The idler gear meshes with the right differential gear.

[0012] In the above-mentioned agricultural machinery gearbox, a first mounting base and a second mounting base are arranged parallel to each other on one side of the gearbox body. The first hydrostatic transmission device is fixedly connected to the first mounting base, and the second hydrostatic transmission device is fixedly connected to the second mounting base. The input shafts and output shafts of the first hydrostatic transmission device and the second hydrostatic transmission device are arranged vertically.

[0013] In the above-mentioned agricultural machinery gearbox, the main input gear is centrally located in the front-rear direction, the first hydrostatic transmission device and the second hydrostatic transmission device are distributed front-to-back, and the drive transmission mechanism and the steering transmission mechanism are distributed front-to-back.

[0014] Compared with the prior art, this utility model has the following advantages:

[0015] 1. This utility model provides an agricultural machinery gearbox that employs two input gears of a hydrostatic transmission device directly meshing on both sides of the main input gear. This significantly reduces the axial dimension, resulting in a more compact structure suitable for space-constrained agricultural machinery. It offers advantages such as compact structure, reasonable layout, and fast output response. Furthermore, the input gears of the two hydrostatic transmission devices in this utility model can be independently designed with transmission ratios, dynamically distributing power according to working conditions to avoid insufficient driving force.

[0016] 2. This utility model further improves the gear transmission structure in the gearbox, reduces the number of gears, shortens the transmission path, improves transmission efficiency, and has a faster response speed. This utility model uses a shift fork to drive the synchronizer for gear shifting. Compared with the existing double gear sliding gear shifting method on the shaft, the shifting time is shorter, the shifting success rate is higher, and the gear life is longer. Attached Figure Description

[0017] Figure 1 This is a transmission structure diagram of this utility model;

[0018] Figure 2 yes Figure 1 AA section view;

[0019] Figure 3 yes Figure 1 BB section view;

[0020] Figure 4 This is a side view of the present invention;

[0021] Reference numerals in the attached diagram: 1. Planetary differential mechanism; 2. Intermediate gear; 3. Differential gear; 4. Housing; 5. Main input gear; 6. First hydrostatic transmission input gear; 7. Second hydrostatic transmission input gear; 8. Drive input gear; 9. Steering input gear; 10. Shift gear set; 11. Transmission gear set; 12. Shift fork; 13. Synchronizer; 14. Shift rocker arm; 15. Brake mechanism; 16. Double gear; 17. Reverse gear set; 18. Idler gear; 19. First mounting base; 20. Second mounting base. Detailed Implementation

[0022] The present invention will be further described below with reference to the accompanying drawings and specific embodiments. See also: Figure 1-4 :

[0023] An agricultural machinery gearbox includes an input shaft, a drive transmission mechanism, a steering transmission mechanism, and a planetary differential mechanism 1. The input shaft is connected to a power unit. The drive transmission mechanism is connected to the intermediate gear 2 of the planetary differential mechanism 1. The steering transmission mechanism is connected to the differential gear 3 of the planetary differential mechanism 1. A first hydrostatic transmission device and a second hydrostatic transmission device are arranged parallel to each other outside the gearbox housing 4. A main input gear 5 is provided on the input shaft. A first hydrostatic transmission input gear 6 and a second hydrostatic transmission input gear 7 are respectively meshed on both sides of the main input gear 5. The input shaft of the first hydrostatic transmission device is splinedly connected to the first hydrostatic transmission input gear 6, and its output shaft is splinedly connected to the drive input gear 8. The input shaft of the second hydrostatic transmission device is splinedly connected to the second hydrostatic transmission input gear 7, and its output shaft is splinedly connected to the steering input gear 9.

[0024] Furthermore, the drive transmission mechanism includes a drive input gear 8, a shift gear set 10, and a transmission gear set 11. The shift gear set 10 includes a shift input gear, a first gear and a second gear loosely fitted on the gear shaft. The first gear and the second gear are selectively connected to the gear shaft. The transmission gear set 11 includes a primary transmission gear and a secondary transmission gear. The primary transmission gear meshes with the first gear and the intermediate gear 2, and the secondary transmission gear meshes with the second gear.

[0025] Furthermore, the steering transmission mechanism includes a steering input gear 9, a double gear 16, a reverse gear set 17, and an idler gear 18. The two gears of the double gear 16 mesh with the steering input gear 9 and the gear in the middle of the reverse gear set 17, respectively. The gear on the left side of the reverse gear set 17 meshes with the left differential gear 3, and the gear on the right side meshes with the idler gear 18. The idler gear 18 meshes with the right differential gear 3.

[0026] This embodiment uses a hydrostatic transmission as the external drive source. The first hydrostatic transmission drives the vehicle in a straight line during driving and, in conjunction with synchronizer 13, enables gear shifting. The second hydrostatic transmission participates during steering and, in conjunction with the planetary differential, enables the forward and reverse rotation required for steering. Specifically:

[0027] After the power is adjusted by the variable pump and fixed displacement motor of the first hydrostatic transmission device, it enters the shift gear set 10 through the drive input gear 8. The driver operates the shift rocker arm 14, which drives the synchronizer 13 through the shift fork 12, so that the first or second gear is engaged with the gear shaft of the shift gear set 10. The power is then transmitted to the intermediate gear 2 of the planetary differential mechanism 1 through the transmission gear set 11, and finally the wheels are driven by the half shaft.

[0028] When steering is required, the second hydrostatic transmission device intervenes, and power enters the steering transmission mechanism via the steering input gear 9. The steering input gear 9 drives the double gear 16, which changes the direction of rotation via the reversing gear set 17 and the idler gear 18, acting on the differential gears 3 on both sides of the planetary differential. For example, when turning left, the left differential gear 3 decelerates, while the right differential gear 3 maintains its original speed or increases its speed. The differential is achieved through the rotation of the planetary gears, making the left wheel slower and the right wheel faster, thus completing the steering.

[0029] The shifting structure of this embodiment is as follows: a synchronizer 13 driven by a shift fork 12 is slidably disposed on the gear shaft of the shifting gear set 10. The synchronizer 13 changes the transmission state between the gear shaft and the first gear and the second gear by axial movement. The shift fork 12 is driven by a shift rocker arm 14, which extends to the outside of the housing 4. Furthermore, the connection structure between the shift fork 12 and the synchronizer 13 is as follows: an annular groove is provided on the outer periphery of the gear sleeve of the synchronizer 13, and the end of the shift fork 12 is embedded in the annular groove to drive the synchronizer 13 to move axially.

[0030] The power transmission process during gear shifting is as follows: When synchronizer 13 engages with the first gear, the first gear drives the first-stage transmission gear meshing with it to rotate, the first-stage transmission gear drives the intermediate gear 2 meshing with it to rotate, and at the same time the second-stage transmission gear and the second gear rotate freely; when synchronizer 13 engages with the second gear, the second gear drives the second-stage transmission gear meshing with it to rotate, and then sequentially drives the intermediate gear 2 to rotate through the gear shaft of transmission gear set 11 and the first-stage transmission gear, while the first gear rotates freely.

[0031] This embodiment further includes a braking structure: a braking mechanism 15 for braking the gear shaft is provided on one side of the transmission gear set 11; the braking mechanism 15 is a hydraulic brake or a friction brake. The braking mechanism 15 acts on the shaft end of the transmission gear set 11, and deceleration is achieved through multiple friction plates or a hydraulic structure. During braking, the first hydrostatic transmission device is simultaneously unloaded to avoid power impact.

[0032] This embodiment further optimizes the layout to make the structure more compact. A first mounting base 19 and a second mounting base 20 are arranged parallel to each other on one side of the housing 4. The first hydrostatic transmission device is fixedly connected to the first mounting base 19, and the second hydrostatic transmission device is fixedly connected to the second mounting base 20. The input and output shafts of both the first and second hydrostatic transmission devices are arranged vertically. Furthermore, the main input gear 5 is centrally located in the front-to-back direction, and the first and second hydrostatic transmission devices are distributed front-to-back, as are the drive transmission mechanism and steering transmission mechanism.

[0033] The above embodiments are merely preferred embodiments of the present utility model and are not intended to limit the scope of protection of the present utility model. Therefore, all equivalent changes made to the structure, shape, and principle of the present utility model should be covered within the scope of protection of the present utility model.

Claims

1. An agricultural machinery gearbox, comprising an input shaft, a drive transmission mechanism, a steering transmission mechanism, and a planetary differential mechanism, wherein the input shaft is connected to a power unit, the drive transmission mechanism is connected to an intermediate gear (2) of the planetary differential mechanism (1), and the steering transmission mechanism is connected to a differential gear (3) of the planetary differential mechanism, characterized in that, A first hydrostatic transmission device and a second hydrostatic transmission device are arranged parallel to each other outside the gearbox housing (4). A main input gear (5) is provided on the input shaft. A first hydrostatic transmission input gear (6) and a second hydrostatic transmission input gear (7) are respectively meshed on both sides of the main input gear (5). The input shaft of the first hydrostatic transmission device is splinedly connected to the first hydrostatic transmission input gear (6), and the output shaft is splinedly connected to the drive input gear (8). The input shaft of the second hydrostatic transmission device is splinedly connected to the second hydrostatic transmission input gear (7), and the output shaft is splinedly connected to the steering input gear (9).

2. The agricultural machinery gearbox according to claim 1, characterized in that, The drive transmission mechanism includes a drive input gear (8), a shift gear set (10), and a transmission gear set (11). The shift gear set (10) includes a shift input gear, a first gear and a second gear loosely fitted on the gear shaft. The first gear and the second gear are selectively connected to the gear shaft. The transmission gear set (11) includes a first-stage transmission gear and a second-stage transmission gear. The first-stage transmission gear meshes with the first gear and the intermediate gear (2), and the second-stage transmission gear meshes with the second gear.

3. The agricultural machinery gearbox according to claim 2, characterized in that, The shift gear set (10) has a synchronizer (13) driven by a shift fork (12) slidably mounted on the gear shaft. The synchronizer (13) changes the transmission state between the gear shaft and the first gear and the second gear by axial movement. The shift fork (12) is driven by a shift rocker arm (14), which extends to the outside of the housing (4).

4. An agricultural machinery gearbox according to claim 2, characterized in that, A brake mechanism (15) for braking its gear shaft is provided on one side of the gear set (11).

5. An agricultural machinery gearbox according to claim 1, characterized in that, The steering transmission mechanism includes a steering input gear (9), a double gear (16), a reverse gear set (17), and an idler gear (18). The two gears of the double gear (16) mesh with the steering input gear (9) and the gear in the middle of the reverse gear set (17), respectively. The gear on the left side of the reverse gear set (17) meshes with the left differential gear (3), and the gear on the right side meshes with the idler gear (18). The idler gear (18) meshes with the right differential gear (3).

6. An agricultural machinery gearbox according to claim 1, characterized in that, The housing (4) has a first mounting base (19) and a second mounting base (20) arranged in parallel on one side. The first hydrostatic transmission device is fixedly connected to the first mounting base (19), and the second hydrostatic transmission device is fixedly connected to the second mounting base (20). The input shaft and output shaft of the first hydrostatic transmission device and the second hydrostatic transmission device are arranged vertically.

7. An agricultural machinery gearbox according to claim 1, characterized in that, The main input gear (5) is centrally located in the front-to-back direction, the first hydrostatic transmission device and the second hydrostatic transmission device are distributed front to back, and the drive transmission mechanism and the steering transmission mechanism are distributed front to back.

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