A drive system for an agricultural tractor

Abstract

The application belongs to the field of agricultural tractor technology, and particularly relates to a transmission system of an agricultural tractor, which comprises a reduction gearbox and a differential assembly, a mandrel and a walking output shaft are arranged in the reduction gearbox, the mandrel is in transmission connection with an input shaft of a hydrostatic stepless speed change device through an intermediate shaft assembly, an output shaft of the hydrostatic stepless speed change device is in transmission connection with the walking output shaft through a transmission gear assembly one, the intermediate shaft assembly comprises an intermediate shaft, an intermediate gear one and an intermediate gear two, a hydraulic pump is arranged on the reduction gearbox, an input gear two is sleeved on an input shaft of the hydraulic pump, a hydraulic motor is arranged on the differential assembly, and an output shaft of the hydraulic motor is in transmission connection with one differential output shaft. Two hydrostatic stepless speed change devices are adopted in the application, and one of the hydrostatic stepless speed change devices is disassembled into a hydraulic pump and a hydraulic motor. When turning, the two driving wheels on the tractor can be driven to rotate forward and reversely, so that the agricultural tractor can be turned in place.

Description

TECHNICAL FIELD

[0001] The present application belongs to the technical field of agricultural tractors, and particularly relates to a transmission system of an agricultural tractor. BACKGROUND

[0002] A kind of agricultural tractor disclosed in the prior Chinese invention patent (authorized announcement number CN104747663B) includes frame, engine, speed reducer, intermediate transmission shaft assembly, clutch, differential and drive wheel assembly, the box of speed reducer is provided with as first power input core shaft, the outer spline sleeve that is packaged on core shaft and as second power input, walking output shaft that is output torque to intermediate transmission shaft assembly, and, rotary tillage mechanism output power rotary tillage output shaft;The core shaft is transmitted torque to walking output shaft by intermediate shaft assembly and transmission gear assembly, the outer spline sleeve is transmitted torque to rotary tillage output shaft by intermediate shaft assembly and transmission gear assembly;And, core shaft is driven by center shaft assembly and input shaft of stepless speed changer, and the output shaft of stepless speed changer is driven by transmission gear assembly and walking output shaft.

[0003] Among them, the above-mentioned agricultural tractor disclosed in the turning is same as the steering principle of car, is all with the help of differential to coordinate the rotational speed between two drive wheels, so that two drive wheels are rolled at different rotational speeds.But correspondingly, the turning radius of agricultural tractor is large, it is difficult to realize turning in narrow paddy field operation, at the same time, the time required for turning of agricultural tractor is long, i.e. non-operation time is long, affect the efficiency of overall agricultural operation. SUMMARY

[0004] The purpose of the present application is to provide a kind of transmission system of agricultural tractor, when turning, two drive wheels are respectively carried out positive rotation and reverse rotation, so that agricultural tractor can be turned around.

[0005] The present application is realized as follows:

[0006] The transmission system of the agricultural tractor comprises a reduction gearbox and a differential assembly, a walking output shaft is arranged in the reduction gearbox and is in transmission with a differential input shaft of the differential assembly, a core shaft is in transmission connection with an input shaft of a hydrostatic stepless speed change device through an intermediate shaft assembly, an output shaft of the hydrostatic stepless speed change device is in transmission connection with the walking output shaft through a transmission gear assembly, two differential output shafts of the differential assembly are respectively connected with corresponding side drive wheel assemblies, the intermediate shaft assembly comprises an intermediate row shaft arranged in the reduction gearbox and in transmission connection with the core shaft, and an intermediate gear one and an intermediate gear two sleeved on the intermediate row shaft, an input gear one in mesh with the intermediate gear one is sleeved on the input shaft of the hydrostatic stepless speed change device, a hydraulic pump is arranged on the reduction gearbox, an input gear two in mesh with the intermediate gear two is sleeved on an input shaft of the hydraulic pump, a hydraulic motor in hydraulic transmission cooperation with the hydraulic pump is arranged on the differential assembly, and the hydraulic motor and the hydraulic pump are controlled to be started or stopped by a control assembly, an output shaft of the hydraulic motor is in transmission connection with one of the differential output shafts of the differential assembly, and the hydraulic motor can drive the corresponding differential output shaft to rotate reversely.

[0007] In the transmission system of the agricultural tractor, a steering row shaft is rotationally connected to the differential assembly, a steering gear one is sleeved on the steering row shaft, an output gear two in mesh with the steering gear one is sleeved on the output shaft of the hydraulic motor, a steering gear two is sleeved on the corresponding differential output shaft of the differential assembly, and the steering gear one and the steering gear two are in transmission connection through a planetary reduction gear assembly.

[0008] In the transmission system of the agricultural tractor, the planetary reduction gear assembly comprises a gear ring and a reduction rotating shaft rotationally connected to the differential assembly, a sun gear sleeved on the reduction rotating shaft, and a planetary gear in mesh with the sun gear and the gear ring and rotationally connected to a planet carrier, a transmission outer tooth one in mesh with the steering gear one is arranged on the outer periphery of the gear ring, a transmission outer tooth two in mesh with the steering gear two is arranged on the outer periphery of the planet carrier, a reduction driven gear is sleeved on the reduction rotating shaft, a differential housing matched with the differential input shaft and the two differential output shafts is rotationally connected to the differential assembly, and a reduction driving gear in mesh with the reduction driven gear is sleeved on the differential housing.

[0009] In the transmission system of the agricultural tractor, a drive shaft corresponding to the differential output shaft is rotationally connected to the differential assembly, a drive driven gear one and a drive driving gear two are sleeved on the drive shaft, a drive driving gear one in mesh with the corresponding drive driven gear one is sleeved on the two differential output shafts, the drive wheel assembly comprises a rotating shaft rotationally connected to the differential assembly and a drive wheel sleeved on the rotating shaft, and a drive driven gear two in mesh with the drive driving gear two is sleeved on the rotating shaft.

[0010] In the transmission system of the agricultural tractor, the core shaft is sleeved with a power gear one, and the intermediate shaft is sleeved with a power gear two engaged with the power gear one.

[0011] In the transmission system of the agricultural tractor, the transmission gear assembly one comprises a walking intermediate shaft and a walking transmission shaft rotatably connected to the reduction box, the walking intermediate shaft is sleeved with a first walking driving gear, a second walking driving gear, a third walking driving gear and a fourth walking driving gear, and the walking transmission shaft is sleeved with a first walking driven gear, a second walking driven gear, a third walking driven gear and a fourth walking driven gear engaged with the first walking driving gear, the second walking driving gear, the third walking driving gear and the fourth walking driving gear respectively, the third walking driving gear and the fourth walking driving gear are rotatable relative to the walking intermediate shaft, and a gear shifting yoke assembly one is arranged between the third walking driving gear and the fourth walking driving gear, the gear shifting yoke assembly one is engaged with the corresponding driving gear to realize synchronous rotation of the corresponding driving gear and the walking intermediate shaft, the first walking driven gear and the second walking driven gear are rotatable relative to the walking transmission shaft, and a gear shifting yoke assembly two is arranged between the first walking driven gear and the second walking driven gear, the gear shifting yoke assembly two is engaged with the corresponding driven gear to realize synchronous rotation of the corresponding driven gear and the walking transmission shaft, the output shaft of the hydrostatic stepless speed change device is sleeved with an output gear one engaged with the first walking driving gear, the walking transmission shaft is sleeved with a power gear three, and the walking output shaft is sleeved with a power gear four engaged with the power gear three.

[0012] In the transmission system of the agricultural tractor, the reduction box is rotatably connected with a rotary tillage output shaft, the core shaft is sleeved with a spline sleeve rotatable relative to the core shaft, and the spline sleeve and the rotary tillage output shaft are drivingly connected through the transmission gear assembly two.

[0013] In the transmission system of the agricultural tractor, the transmission gear assembly two comprises a rotary tillage intermediate shaft and a rotary tillage transmission shaft rotatably connected to the reduction box, the rotary tillage intermediate shaft is sleeved with a rotary tillage gear one engaged with the outer teeth of the spline sleeve, the rotary tillage transmission shaft is sleeved with a first rotary tillage driving gear, a second rotary tillage driving gear, a third rotary tillage driving gear and a rotary tillage gear two engaged with the rotary tillage gear one, and the rotary tillage output shaft is rotatably sleeved with a first rotary tillage driven gear, a second rotary tillage driven gear and a third rotary tillage driven gear engaged with the first rotary tillage driving gear, the second rotary tillage driving gear and the third rotary tillage driving gear respectively, and gear shifting yoke assembly three is arranged between the first rotary tillage driven gear and the second rotary tillage driven gear, and between the second rotary tillage driven gear and the third rotary tillage driven gear, the gear shifting yoke assembly three is engaged with the corresponding driven gear to realize synchronous rotation of the corresponding driven gear and the rotary tillage output shaft.

[0014] In the transmission system of the agricultural tractor, one end of the walking transmission shaft is provided with a hydraulic brake device capable of braking the walking transmission shaft, and the hydraulic brake device is electrically connected with the control assembly.

[0015] In the transmission system of the agricultural tractor, the hydraulic brake device comprises a brake housing arranged on the reduction gearbox, and the corresponding end of the walking transmission shaft extends into the inner cavity of the brake housing and is sleeved with a brake shaft sleeve.

[0016] The outstanding advantages of the present application compared with the prior art are:

[0017] The transmission system of the present application adopts two hydrostatic stepless speed change devices, one of which is used for power transmission between the mandrel and the walking output shaft, and the other is split into a hydraulic pump mounted on the reduction gearbox and a hydraulic motor mounted on the differential assembly. BRIEF DESCRIPTION OF DRAWINGS

[0018] Figure 1 is a transmission structure sectional view of the transmission system of the present application;

[0019] Figure 2 is a transmission structure sectional view of the reduction gearbox of the present application;

[0020] Figure 3 is a structure sectional view of the hydraulic brake device of the present application;

[0021] Figure 4 is a transmission structure sectional view of the differential assembly of the present application.

[0022] Figure: 1, reduction gearbox; 2, differential assembly; 3, mandrel; 4, walking output shaft; 5, differential input shaft; 6, differential output shaft; 7, hydrostatic stepless speed change device; 8, intermediate row shaft; 9, intermediate gear 1; 10, intermediate gear 2; 11, input gear 1; 12, hydraulic pump; 13, input gear 2; 14, hydraulic motor; 15, turning row shaft; 16, turning gear 1; 17, output gear 2; 18, turning gear 2; 19, ring gear; 20, reduction rotation shaft; 21, sun gear; 22, planet carrier; 23, planet gear; 24, reduction driven gear; 25, differential housing; 26, reduction driving gear; 27, driving shaft; 28, driving driven gear 1; 29, driving driving gear 2; 30, driving driving gear 1; 31, rotation shaft; 32, driving wheel; 33, driving driven gear 2; 34, power gear 1; 35, walking intermediate shaft; 36, walking transmission shaft; 37, one-gear walking driving tooth; 38, two-gear walking driving tooth; 39, three-gear walking driving tooth; 40, four-gear walking driving tooth; 41, one-gear walking driven tooth; 42, two-gear walking driven tooth; 43, three-gear walking driven tooth; 44, four-gear walking driven tooth; 45, shift fork assembly 1; 46, shift fork assembly 2; 47, output gear 1; 48, power gear 3; 49, power gear 4; 50, rotary tillage output shaft; 51, spline sleeve; 52, rotary tillage intermediate shaft; 53, rotary tillage transmission shaft; 54, rotary tillage gear 1; 55, one-gear rotary tillage driving tooth; 56, two-gear rotary tillage driving tooth; 57, three-gear rotary tillage driving tooth; 58, rotary tillage gear 2; 59, one-gear rotary tillage driven tooth; 60, two-gear rotary tillage driven tooth; 61, three-gear rotary tillage driven tooth; 62, shift fork assembly 3; 63, hydraulic brake device; 64, brake housing; 65, brake shaft sleeve; 66, brake sliding seat; 67, brake driving cavity; 68, brake passage; 69, return spring; 70, inner friction plate; 71, outer friction plate; 72, sealing block. DETAILED DESCRIPTION

[0023] The application is further described in the following specific examples, with reference to Figure 1 -4:

[0024] The transmission system of the agricultural tractor comprises a reduction box 1 and a differential assembly 2, the reduction box 1 is internally provided with a mandrel 3 and a walking output shaft 4 which is in transmission with a differential input shaft 5 of the differential assembly 2, the mandrel 3 is in transmission connection with an input shaft of a hydrostatic stepless speed change device 7 through an intermediate shaft assembly, an output shaft of the hydrostatic stepless speed change device 7 is in transmission connection with the walking output shaft 4 through a transmission gear assembly, two differential output shafts 6 of the differential assembly 2 are respectively connected with corresponding side shift fork assemblies, the intermediate shaft assembly comprises an intermediate walking shaft 8 which is arranged in the reduction box 1 and in transmission connection with the mandrel 3, and a first intermediate gear 9 and a second intermediate gear 10 which are sleeved on the intermediate walking shaft 8, an input gear 11 which is in meshing with the first intermediate gear 9 is sleeved on the input shaft of the hydrostatic stepless speed change device 7, a hydraulic pump 12 is arranged on the reduction box 1, an input gear 13 which is in meshing with the second intermediate gear 10 is sleeved on an input shaft of the hydraulic pump 12, a hydraulic motor 14 which is in hydraulic transmission cooperation with the hydraulic pump 12 is arranged on the differential assembly 2, and the hydraulic motor 14 and the hydraulic pump 12 are controlled to be opened or closed by a control assembly, an output shaft of the hydraulic motor 14 is in transmission connection with one of the differential output shafts 6 of the differential assembly 2, and the hydraulic motor 14 can drive the corresponding differential output shaft 6 to rotate reversely.

[0025] Compared with the prior art, the transmission system of the present application adopts two hydrostatic stepless speed change devices, one of which is used for power transmission between the mandrel 3 and the walking output shaft 4, and the other is split into the hydraulic pump 12 arranged on the reduction box 1 and the hydraulic motor 14 arranged on the differential assembly 2, when turning, the control assembly starts the hydraulic pump 12 and the hydraulic motor 14, so that the hydraulic pump 12 can receive the torque transmitted from the mandrel 3 and drive the corresponding output shaft of the differential assembly 2 to rotate reversely through the hydraulic motor 14, thereby realizing that the two driving wheels 32 of the tractor rotate forwardly and reversely respectively, so that the agricultural tractor can turn in place.

[0026] Moreover, since the hydrostatic stepless speed change device composed of the hydraulic pump 12 and the hydraulic motor 14 is the prior art in the technical field, the specific cooperation principle between the hydraulic pump 12 and the hydraulic motor 14 in the hydrostatic stepless speed change device will not be described in detail in the present application.

[0027] In order to enable the hydraulic motor 14 to drive the corresponding differential output shaft 6 of the differential assembly 2 to rotate reversely, and also to reduce the rotating speed of the hydraulic motor 14 and increase the torque thereof, a steering axle 15 is rotatably connected to the differential assembly 2, a steering gear one 16 is sleeved on the steering axle 15, an output gear two 17 which is engaged with the steering gear one 16 is sleeved on the output shaft of the hydraulic motor 14, a steering gear two 18 is sleeved on the corresponding differential output shaft 6 of the differential assembly 2, and the steering gear one 16 and the steering gear two 18 are drivingly connected through a planetary reduction gear assembly.

[0028] Furthermore, the planetary reduction gear assembly is specifically arranged on the differential assembly 2 as follows: the planetary reduction gear assembly comprises a gear ring 19 and a reduction rotating shaft 20 which are rotatably connected to the differential assembly 2, a sun gear 21 which is sleeved on the reduction rotating shaft 20, and a planet gear 23 which is engaged with the sun gear 21 and the gear ring 19 and is rotatably connected to a planet carrier 22, the outer periphery of the gear ring 19 is provided with a driving outer tooth one which is engaged with the steering gear one 16, and the outer periphery of the planet carrier 22 is provided with a driving outer tooth two which is engaged with the steering gear two 18; in order to further reduce the rotating speed of the planet carrier 22 transmitted to the steering gear two 18, a reduction driven gear 24 is sleeved on the reduction rotating shaft 20, a differential housing 25 which is matched with the differential input shaft 5 and the two differential output shafts 6 is rotatably connected to the differential assembly 2, and a reduction driving gear 26 which is engaged with the reduction driven gear 24 is sleeved on the differential housing 25. That is, the differential housing 25 rotates forwardly under the driving of the differential input shaft 5, the reduction rotating shaft 20 and the sun gear 21 rotate reversely under the engagement of the reduction driving gear 26 and the reduction driven gear 24, the gear ring 19 rotates forwardly under the driving of the steering gear one 16 and its rotating speed is greater than that of the sun gear 21, therefore the planet gear 23 rotates forwardly while self-rotating, and the steering gear two 18 and the corresponding differential output shaft 6 can rotate reversely. In addition, the other differential output shaft 6 rotates forwardly under the cooperation of the differential housing 25 and the planetary gear assembly in the differential.

[0029] In order to improve the transmission stability of the shift fork assembly and avoid using a shaft with a long length for transmission to reduce the cost, a driving shaft 27 which is matched with the differential output shaft 6 one-to-one is rotatably connected to the differential assembly 2, a driving driven gear one 28 and a driving driving gear two 29 are sleeved on the driving shaft 27, a driving driving gear one 30 which is engaged with the corresponding driving driven gear one 28 is sleeved on the two differential output shafts 6, the shift fork assembly comprises a rotating shaft 31 which is rotatably connected to the differential assembly 2 and a driving wheel 32 which is sleeved on the rotating shaft 31, and a driving driven gear two 33 which is engaged with the driving driving gear two 29 is sleeved on the rotating shaft 31.

[0030] In addition, the transmission between the mandrel 3 and the intermediate axle 8 can be that the mandrel 3 is sleeved with a power gear one 34, and the intermediate axle 8 is sleeved with a power gear two engaged with the power gear one 34. In order to reduce the number of parts, in the embodiment, the intermediate gear two 10 is directly engaged with the power gear one 34 for transmission.

[0031] In the embodiment, in order to realize the multi-gear function of the agricultural tractor, the specific transmission structure of the output shaft of the hydrostatic stepless speed change device 7 and the walking output shaft 4 through the transmission gear assembly one is that the transmission gear assembly one includes a walking intermediate shaft 35 and a walking transmission shaft 36 rotatably connected to the reduction box 1. The walking intermediate shaft 35 is sleeved with a first-gear walking driving gear 37, a second-gear walking driving gear 38, a third-gear walking driving gear 39, and a fourth-gear walking driving gear 40. The walking transmission shaft 36 is sleeved with a first-gear walking driven gear 41, a second-gear walking driven gear 42, a third-gear walking driven gear 43, and a fourth-gear walking driven gear 44 engaged with the first-gear walking driving gear 37, the second-gear walking driving gear 38, the third-gear walking driving gear 39, and the fourth-gear walking driving gear 40, respectively. The first-gear walking driving gear 37 and the second-gear walking driving gear 38 can rotate relative to the walking intermediate shaft 35, and a shift yoke assembly one 45 is arranged between the first-gear walking driving gear 37 and the second-gear walking driving gear 38. The shift yoke assembly one 45 is engaged with the corresponding driving gear to realize the synchronous rotation of the corresponding driving gear and the walking intermediate shaft 35. The third-gear walking driven gear 43 and the fourth-gear walking driven gear 44 can rotate relative to the walking transmission shaft 36, and a shift yoke assembly two 46 is arranged between the third-gear walking driven gear 43 and the fourth-gear walking driven gear 44. The shift yoke assembly two 46 is engaged with the corresponding driven gear to realize the synchronous rotation of the corresponding driven gear and the walking transmission shaft 36. The output shaft of the hydrostatic stepless speed change device 7 is sleeved with an output gear one 47 engaged with the third-gear walking driving gear 39 or the fourth-gear walking driving gear 40. The walking transmission shaft 36 is sleeved with a power gear three 48. The walking output shaft 4 is sleeved with a power gear four 49 engaged with the power gear three 48.

[0032] The reduction box 1 is provided with a walking speed change shift lever for engaging the shift yoke assembly one 45 and the shift yoke assembly two 46 with the corresponding driving gear or driven gear. The shift yoke assembly one 45 is engaged with the first-gear walking driving gear to realize the first-gear transmission of the tractor walking. The shift yoke assembly one 45 is engaged with the second-gear walking driving gear 38 to realize the second-gear transmission of the tractor walking. The shift yoke assembly two 46 is engaged with the third-gear walking driven gear 43 to realize the third-gear transmission of the tractor walking. The shift yoke assembly two 46 is engaged with the fourth-gear walking driven gear 44 to realize the fourth-gear transmission of the tractor walking.

[0033] Further, in order to brake the transmission gear assembly to achieve the purpose of braking the tractor, one end of the walking transmission shaft 36 is provided with a hydraulic brake device 63 capable of braking the walking transmission shaft 36, the hydraulic brake device 63 is electrically connected with the control assembly, and the opening and closing of the hydraulic brake device 63 is controlled by the control assembly. The control assembly can be connected with the brake pedal of the agricultural tractor, and the driver steps on the brake pedal to control the control assembly to brake the walking transmission shaft 36 by the hydraulic brake device 63.

[0034] The hydraulic brake device 63 can adopt the existing common structure, and in the embodiment, the specific structure of the hydraulic brake device 63 is that the hydraulic brake device 63 comprises a brake housing 64 arranged on the reduction gearbox 1, the corresponding end of the walking transmission shaft 36 extends into the inner cavity of the brake housing 64 and is sleeved with a brake shaft sleeve 65, a brake sliding seat 66 is slidably connected in the inner cavity of the brake housing 64 along the axial direction of the walking transmission shaft 36, a brake driving cavity 67 is formed between the side wall of the brake sliding seat 66 away from the walking transmission shaft 36 and the brake housing 64, a brake channel 68 is formed on the brake housing 64 and communicates the brake driving cavity 67 with the external hydraulic power source, a reset spring 69 is arranged between the brake sliding seat 66 and the brake housing 64 and can push the brake sliding seat 66 away from the walking transmission shaft 36, an inner friction plate 70 is fixed on the brake shaft sleeve 65 in the circumferential direction, an outer friction plate 71 is arranged on the brake sliding seat 66 and matched with the inner friction plate 70, and the outer friction plate 71 and the inner friction plate 70 are axially spaced apart. That is, the high-pressure liquid is injected into the brake driving cavity 67 from the external hydraulic power source through the brake channel 68, so that the brake sliding seat 66 moves towards the walking transmission shaft 36 under the pushing of the high-pressure liquid and overcomes the elastic force of the reset spring 69, thereby promoting the inner friction plate 70 and the outer friction plate 71 to rub and brake; when the braking is finished, the hydraulic pressure in the brake driving cavity 67 is reduced, the brake sliding seat 66 moves away from the walking transmission shaft 36 under the driving of the elastic force of the reset spring 69, and the inner friction plate 70 and the outer friction plate 71 are separated.

[0035] In addition, in order to drive the rotation of the rotary tillage mechanism of the agricultural tractor, the reduction gearbox 1 is rotationally connected with a rotary tillage output shaft 50, the mandrel 3 is sleeved with a spline sleeve 51 capable of rotating relative to the mandrel 3, and the spline sleeve 51 and the rotary tillage output shaft 50 are drivingly connected through the second transmission gear assembly. The mandrel 3 and the spline sleeve 51 are drivingly connected with the engine of the tractor, and the specific driving connection structure is the prior art in the technical field, which is not described in the specification.

[0036] And, in order to make the rotary tillage mechanism have multi-gear rotation adjustment, the transmission gear assembly two includes a rotary tillage intermediate shaft 52 rotationally connected to the reduction box 1 and a rotary tillage transmission shaft 53, the rotary tillage intermediate shaft 52 is sleeved with a rotary tillage gear one 54 meshing with the outer gear of the spline sleeve 51, the rotary tillage transmission shaft 53 is sleeved with a one-gear rotary tillage driving gear 55, a two-gear rotary tillage driving gear 56, a three-gear rotary tillage driving gear 57 and a rotary tillage gear two 58 meshing with the rotary tillage gear one 54, the rotary tillage output shaft 50 is rotationally sleeved with a one-gear rotary tillage driven gear 59, a two-gear rotary tillage driven gear 60 and a three-gear rotary tillage driven gear 61 meshing with the one-gear rotary tillage driving gear 55, the two-gear rotary tillage driving gear 56 and the three-gear rotary tillage driving gear 57 respectively, and a gear shifting fork assembly three 62 is arranged between the one-gear rotary tillage driven gear 59 and the two-gear rotary tillage driven gear 60 and between the two-gear rotary tillage driven gear 60 and the three-gear rotary tillage driven gear 61, the gear shifting fork assembly three 62 is engaged with the corresponding driven gear to realize synchronous rotation of the corresponding driven gear and the rotary tillage output shaft 50. The rotary tillage transmission gear assembly one is the same as the above, the reduction box 1 is provided with a rotary tillage gear shifting lever for driving the gear shifting fork assembly three 62 to engage with the corresponding driven gear, that is, the gear shifting fork assembly three 62 is engaged with the one-gear rotary tillage driven gear to realize one-gear rotary tillage operation of the rotary tillage mechanism, the gear shifting fork assembly three 62 is engaged with the two-gear rotary tillage driven gear to realize two-gear rotary tillage operation of the rotary tillage mechanism, and the gear shifting fork assembly three 62 is engaged with the three-gear rotary tillage driven gear to realize three-gear rotary tillage operation of the rotary tillage mechanism.

[0037] At the same time, in order to enable the mandrel 3 to realize sealed transmission in the reduction box 1, the specific matching structure of the mandrel 3 in the reduction box 1 is that the inner end of the mandrel 3 and the inner end of the spline sleeve 51 extend into the reduction box 1, the spline sleeve 51 is rotationally matched with the reduction box 1 through a bearing, the power gear one 34 is in the form of a shaft sleeve, the two ends of the power gear one 34 are rotationally matched with the inner end of the spline sleeve 51 and the reduction box 1 respectively, and the sealing block 72 is connected to the inner hole of the power gear one 34 located outside the inner end of the mandrel 3 through a plunger.

[0038] The above embodiment is only one of the preferred embodiments of the present application, and does not limit the scope of the present application, so that: any equivalent changes made in shape, structure and principle according to the present application should be covered within the protection scope of the present application.

Claims

1. A kind of agricultural tractor transmission system, including reduction gearbox (1) and differential assembly (2), reduction gearbox (1) is equipped with mandrel (3), and the differential input shaft (5) of differential assembly (2) is driven to travel output shaft (4), mandrel (3) is connected with the input shaft of hydrostatic stepless speed change device (7) by intermediate shaft assembly transmission, the output shaft of hydrostatic stepless speed change device (7) is connected with travel output shaft (4) by transmission gear assembly one transmission, the two differential output shafts (6) of differential assembly (2) are connected with corresponding side drive wheel assembly respectively, it is characterized by: The intermediate shaft assembly comprises an intermediate shaft (8) arranged in the reduction box (1) and in transmission connection with the mandrel (3), and an intermediate gear I (9) and an intermediate gear II (10) sleeved on the intermediate shaft (8); an input gear I (11) in mesh with the intermediate gear I (9) is sleeved on the input shaft of the hydrostatic stepless speed change device (7); the reduction box (1) is provided with a hydraulic pump (12), an input gear II (13) in mesh with the intermediate gear II (10) is sleeved on the input shaft of the hydraulic pump (12); the differential assembly (2) is provided with a hydraulic motor (14) in hydraulic transmission cooperation with the hydraulic pump (12), and the hydraulic motor (14) and the hydraulic pump (12) are controlled by the control assembly to be opened or closed; the output shaft of the hydraulic motor (14) is in transmission connection with one differential output shaft (6) of the differential assembly (2), and the hydraulic motor (14) can drive the corresponding differential output shaft (6) to rotate reversely. The differential assembly (2) is rotatably connected with a steering shaft (15), the steering shaft (15) is sleeved with a steering gear I (16), the output shaft of the hydraulic motor (14) is sleeved with an output gear II (17) in mesh with the steering gear I (16), and the corresponding differential output shaft (6) of the differential assembly (2) is sleeved with a steering gear II (18), the steering gear I (16) and the steering gear II (18) are in transmission connection through a planetary reduction gear assembly. The differential assembly (2) is rotatably connected with a drive shaft (27) corresponding to the differential output shaft (6), the drive shaft (27) is sleeved with a drive driven gear I (28) and a drive driving gear II (29), the two differential output shafts (6) are sleeved with a drive driving gear I (30) in mesh with the corresponding drive driven gear I (28), the drive wheel assembly comprises a rotating shaft (31) rotatably connected to the differential assembly (2) and a drive wheel (32) sleeved on the rotating shaft (31), and the rotating shaft (31) is sleeved with a drive driven gear II (33) in mesh with the drive driving gear II (29). The differential assembly (2) is rotatably connected with a differential housing (25) cooperating with the differential input shaft (5) and the two differential output shafts (6), when turning and reversing, the hydraulic pump (12) and the hydraulic motor (14) are started by the control assembly, the hydraulic motor (14) drives the corresponding output shaft of the differential assembly (2) to rotate reversely, and the other output shaft of the differential assembly (2) rotates forwardly under the cooperation of the differential housing (25) and the planetary gear assembly in the differential.

2. A power transmission system for an agricultural tractor as claimed in claim 1, characterized in that: The planetary reduction gear assembly comprises a gear ring (19) and a reduction rotating shaft (20) rotatably connected to the differential assembly (2), a sun gear (21) sleeved on the reduction rotating shaft (20), and a planet gear (23) rotatably connected to a planet carrier (22) and meshing with the sun gear (21) and the gear ring (19), the outer periphery of the gear ring (19) is provided with a transmission outer gear one meshing with the steering gear one (16), the outer periphery of the planet carrier (22) is provided with a transmission outer gear two meshing with the steering gear two (18), and the reduction rotating shaft (20) is sleeved with a reduction driven gear (24), and the differential housing (25) is sleeved with a reduction driving gear (26) meshing with the reduction driven gear (24).

3. A drive system for an agricultural tractor as claimed in claim 1, wherein: The power gear one (34) is sleeved on the mandrel (3), and the power gear two meshing with the power gear one (34) is sleeved on the intermediate axle (8); or the intermediate gear two (10) is in transmission with the power gear one (34).

4. A power transmission system for an agricultural tractor as claimed in claim 1, wherein: The transmission gear assembly one comprises a walking intermediate axle (35) and a walking transmission axle (36) rotatably connected to the reduction box (1), the walking intermediate axle (35) is sleeved with a first gear (37), a second gear (38), a third gear (39) and a fourth gear (40), the walking transmission axle (36) is sleeved with a first driven gear (41), a second driven gear (42), a third driven gear (43) and a fourth driven gear (44) respectively meshing with the first gear (37), the second gear (38), the third gear (39) and the fourth gear (40), the first gear (37) and the second gear (38) can rotate relative to the walking intermediate axle (35), and a gear shifting fork assembly one (45) is arranged between the first gear (37) and the second gear (38), the gear shifting fork assembly one (45) is engaged with the corresponding gear to realize synchronous rotation of the corresponding gear and the walking intermediate axle (35), the third driven gear (43) and the fourth driven gear (44) can rotate relative to the walking transmission axle (36), and a gear shifting fork assembly two (46) is arranged between the third driven gear (43) and the fourth driven gear (44), the gear shifting fork assembly two (46) is engaged with the corresponding driven gear to realize synchronous rotation of the corresponding driven gear and the walking transmission axle (36), the output gear one (47) meshing with the third gear (39) is sleeved on the output shaft of the hydrostatic stepless speed change device (7), the power gear three (48) is sleeved on the walking transmission axle (36), and the power gear four (49) meshing with the power gear three (48) is sleeved on the walking output axle (4).

5. A drive system for an agricultural tractor as claimed in claim 1, wherein: The reduction box (1) is rotatably connected with a rotary tillage output axle (50), the mandrel (3) is sleeved with a spline sleeve (51) capable of rotating relative to the mandrel (3), and the spline sleeve (51) and the rotary tillage output axle (50) are transmission connected through the transmission gear assembly two.

6. A farm tractor transmission system as claimed in claim 5, wherein: The transmission gear assembly two includes a rotary tillage intermediate shaft (52) and a rotary tillage drive shaft (53) rotatably connected to the reduction gearbox (1). The rotary tillage intermediate shaft (52) is fitted with a rotary tillage gear one (54) that meshes with the external teeth of the spline sleeve (51). The rotary tillage drive shaft (53) is fitted with a first-speed rotary tillage drive gear (55), a second-speed rotary tillage drive gear (56), a third-speed rotary tillage drive gear (57), and a rotary tillage gear two (58) that meshes with the first-speed rotary tillage drive gear (54). The rotary tillage output shaft (50) is rotatably fitted with gears that respectively mesh with the first-speed rotary tillage drive gear. (55), the first gear rotary tillage driven gear (59), the second gear rotary tillage driven gear (60) and the third gear rotary tillage driven gear (61) mesh with the second gear rotary tillage driven gear (56) and the third gear rotary tillage driven gear (57), and a shift fork assembly three (62) is provided between the first gear rotary tillage driven gear (59) and the second gear rotary tillage driven gear (60), and between the second gear rotary tillage driven gear (60) and the third gear rotary tillage driven gear (61). The shift fork assembly three (62) engages with the corresponding driven gear to achieve synchronous rotation of the corresponding driven gear and the rotary tillage output shaft (50).

7. A drive system for an agricultural tractor as claimed in claim 4, wherein: One end of the travel drive shaft (36) is provided with a hydraulic braking device (63) that can brake the travel drive shaft (36). The hydraulic braking device (63) is electrically connected to the control assembly, and the control assembly controls the opening or closing of the hydraulic braking device (63).

8. A farm tractor transmission system as claimed in claim 7, wherein: The hydraulic braking device (63) includes a brake housing (64) mounted on the reduction gearbox (1). The corresponding end of the travel drive shaft (36) extends into the inner cavity of the brake housing (64) and is fitted with a brake bushing (65). A brake slide (66) is slidably connected in the inner cavity of the brake housing (64) along the axial direction of the travel drive shaft (36). A brake drive cavity (67) is formed between the side wall of the brake slide (66) away from the travel drive shaft (36) and the brake housing (64). A brake channel (68) is provided on the upper part, which connects the brake drive chamber (67) and the external hydraulic power source. A return spring (69) with elastic force is provided between the brake slide (66) and the brake housing (64) to push the brake slide (66) away from the travel drive shaft (36). An inner friction plate (70) is fixed circumferentially on the brake bushing (65). An outer friction plate (71) is provided on the brake slide (66) to cooperate with the inner friction plate (70), and the outer friction plate (71) and the inner friction plate (70) are axially spaced apart.

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