Power shift gearbox of harvester

Abstract

A power shift gearbox of a harvester comprises a box body, an input shaft arranged in the box body, an intermediate shaft parallel to the input shaft, a differential mechanism connected with the intermediate shaft, and a half shaft connected with a half shaft gear spline of the differential mechanism and parallel to the intermediate shaft, a second-gear clutch and a third-gear clutch are arranged on the input shaft, and a first-gear clutch is arranged on the intermediate shaft. The transmission is characterized in that the two half shafts are respectively provided with a brake which is fixedly connected with the box body, one half shaft is provided with a differential lock which is fixedly connected with the differential mechanism, the second-gear clutch, the third-gear clutch and the first-gear clutch are both wet-type multi-disc clutches which are controlled in an electro-hydraulic mode, and the second-gear clutch, the third-gear clutch and the first-gear clutch are arranged on the box body. The brake is a wet-type multi-disc brake which is electrically and hydraulically controlled and adopts a running and parking integrated mode, and the differential lock is a wet-type multi-disc differential lock which is electrically and hydraulically controlled. The utility model is suitable for long-distance driving and heavy-load work, and has the advantages of strong durability and high adaptability to road conditions.

Description

Technical Field

[0001] The utility model relates to a power shift gearbox for a harvester, belonging to the technical field of gearboxes for harvesters. Background Art

[0002] The gearbox is the core component of the wheeled harvester transmission system, with the functions of traveling and shifting. The existing harvester travel gearboxes all achieve speed change by controlling the meshing sleeve or synchronizer through the shift fork, thereby achieving the speed change of the wheeled harvester. Due to its economy and reliability, it is widely used in small and medium-sized and low-end harvesters. In order to meet the working conditions of the harvester, a service brake and a parking brake system are usually set on its gearbox, that is, the vehicle uses the service brake to slow down and stop during driving; the parking brake is used when parking to prevent the vehicle from slipping. The main problems with the current harvester gearbox are:

[0003] 1. As harvesters develop towards large feed volume, high horsepower and high-end, higher requirements are placed on the transmission power, gear shifting comfort and work efficiency of the travel gearbox. However, the existing conventional gearbox has small input torque, poor power, poor operating performance, easy power interruption during shifting, and poor durability, which can no longer meet people's requirements for comfort and work efficiency.

[0004] 2. Harvesters often use independent systems for the service and parking brakes. A common configuration involves installing service brakes on both output shafts of the transmission for braking while the vehicle is moving, and a parking brake on the other shaft of the transmission for parking. These independent systems take up a lot of space, are complex, and have high manufacturing costs. Furthermore, both the service and parking brakes utilize dry friction disc brakes, which offer poor braking performance, poor heat dissipation, and prone to friction disc wear, resulting in a short service life.

[0005] 3. In the wheeled harvester, the main box is powered by a hydraulic motor, which is transmitted to the driven gear through the driving gear, and then the left and right drive wheels are driven by the left and right half-shafts through the gear-type cross-axis differential integrally connected to the driven gear. If there is no differential lock function, when the harvester encounters a pit or muddy road, the left and right drive wheels will have asynchronous speeds or serious slippage due to the gear-type cross-axis differential function, resulting in limited escape ability and poor road adaptability. The differential lock structure in the existing harvester can only meet the requirements of mechanical structure attachment or electric push rod structure attachment. The attachment mode is single and cannot adapt to complex working conditions, which will lead to attachment difficulties and cannot well realize the differential lock function. Utility Model Content

[0006] The power shift gearbox for the harvester provided by the utility model can realize shifting without power interruption during operation, improve adaptability and operational performance, realize the differential locking function without stopping, and make it easier to get out of a stuck vehicle. It has higher ground adaptability and passability, effectively reduces the spatial volume of the brake, improves the structural compactness and integration, is suitable for long-distance driving and heavy-load work, has strong durability, and is highly adaptable to road working conditions.

[0007] In order to achieve the above purpose, the technical solution adopted by the utility model is:

[0008] The power shift gearbox of the harvester includes a housing, an input shaft installed in the housing, an intermediate shaft parallel to the input shaft, a differential connected to the intermediate shaft, and a half shaft splined to the half shaft gear of the differential and parallel to the intermediate shaft. The second and third gear clutches are installed on the input shaft, and the first gear clutch is installed on the intermediate shaft. The input shaft drives the intermediate shaft and the differential to move with the engagement of the second and third gear clutches or the first gear clutch. It is characterized in that: two half shafts are respectively equipped with brakes fixed to the housing, and one half shaft is equipped with a differential lock fixed to the differential. The second and third gear clutches and the first gear clutch are both wet multi-plate clutches controlled by electro-hydraulic control, the brake is a wet multi-plate brake controlled by electro-hydraulic control and adopts an integrated parking and driving function, and the differential lock is a wet multi-plate differential lock controlled by electro-hydraulic control.

[0009] The second gear driving gear and the third gear driving gear are rotatably mounted on the input shaft, and the second gear driven gear meshing with the second gear driving gear and the third gear driven gear meshing with the third gear driving gear are fixed on the intermediate shaft. The second and third gear clutches are arranged between the second gear driving gear and the third gear driving gear, and include a second and third gear housing coaxially fixed to the input shaft, a second gear piston, a second gear friction plate group corresponding to the second gear piston, a third gear piston and a third gear friction plate group corresponding to the third gear piston are installed in the second and third gear housings, piston cavities for high-pressure oil to enter are respectively formed between the second gear piston and the third gear piston and the second and third gear housings, and an oil path connected to the piston cavity is provided on the input shaft, the second gear friction plate group combines the second gear driving gear with the second and third gear housings as the second gear piston is pressed, and the third gear friction plate group combines the third gear driving gear with the second and third gear housings as the third piston is pressed.

[0010] Preferably, the second-gear friction plate is assembled between the second- and third-gear housing and the second-gear driving gear, and the third-gear friction plate is assembled between the second- and third-gear housing and the third-gear driving gear. The second-gear friction plate group and the third-gear friction plate group have the same structure, both including housing friction plates positioned on the second- and third-gear housings and gear friction plates splined with the third-gear driving gear or the second-gear driving gear. The gear friction plates and housing friction plates are alternately arranged axially and are compressed as the second-gear piston or the third-gear piston pushes them. The input shaft is equipped with a second-gear disc spring corresponding to the second-gear piston and a third-gear disc spring corresponding to the third-gear piston. The second-gear disc spring and the third-gear disc spring are respectively positioned on the input shaft and are both composed of multiple disc springs stacked in sequence. The second-gear disc spring is compressed as the second-gear piston presses the second-gear friction plate group, and the third-gear disc spring is compressed as the third-gear piston presses the third-gear friction plate group.

[0011] Preferably, a first-gear driving gear is integrally formed on the input shaft, and a first-gear driven gear meshing with the first-gear driving gear is rotatably installed on the intermediate shaft. The first-gear clutch includes a first-gear housing coaxially fixed on the intermediate shaft, a first-gear piston and a first-gear friction plate group corresponding to the first-gear piston are installed in the first-gear housing, a piston chamber for high-pressure oil to enter is formed between the first-gear piston and the intermediate shaft, and an oil passage connected to the piston chamber is provided on the intermediate shaft. The first-gear friction plate group combines the first-gear driven gear with the first-gear housing as the first-gear piston is pressed. The first-gear friction plate group has the same structure as the second-gear friction plate group, including a housing friction plate positioned on the first-gear housing and a gear friction plate splined with the first-gear driven gear. The housing friction plate and the gear friction plate are compressed as the first-gear piston pushes. The first-gear housing is equipped with a first-gear disc spring corresponding to the first-gear piston. The first-gear disc spring has the same structure as the second-gear disc spring and is compressed as the first-gear piston presses the first-gear friction plate group.

[0012] Preferably, a secondary constant mesh driving gear is integrally formed on the intermediate shaft, and a secondary constant mesh driven gear meshing with the secondary constant mesh driving gear is fixed on the differential case of the differential. The differential lock includes a differential lock gear coaxially fixed on the half-shaft, a differential lock housing fixed to the differential housing, a differential lock piston movably mounted in the differential lock housing, and a differential lock friction plate group mounted in the differential lock housing and corresponding to the differential lock piston. An oil circuit for high pressure to enter and drive the differential lock piston to move is provided on the differential lock housing, and the differential lock friction plate group combines the differential lock gear with the differential lock housing as the differential lock piston is pressed.

[0013] Preferably, the differential lock friction plate group includes a friction plate 1 positioned in the differential lock housing, a friction plate 2 splined on the differential lock gear, and a differential lock spring installed in the differential lock housing. The friction plate 1 and the friction plate 2 are alternately arranged along the axial direction and are compressed as the differential lock piston pushes. The differential lock spring is compressed as the friction plate 1 and the friction plate 2 are compressed.

[0014] Preferably, the brake includes a brake housing fixed to the housing, in which are installed a brake gear coaxially fixed to the half-shaft, a service brake piston, a parking brake piston abutting the service brake piston, a brake friction plate group corresponding to the service brake piston, and a brake disc spring cooperating with the parking brake piston. The front end of the brake housing is sealed with the housing, and the rear end is sealed through the rear cover end, and the rear cover end is rotatably mounted on the half-shaft. The parking brake piston and the service brake piston respectively form piston cavities with the brake housing for high-pressure oil to enter, and an oil path connected to the piston cavity is opened on the brake housing. The brake disc spring pushes the parking brake piston to press the service brake piston and the brake friction plate group in turn to combine the brake gear with the brake housing.

[0015] Preferably, the brake friction plate group includes a static plate positioned on the brake housing, a dynamic plate that fits on the brake gear with a spline, and a return spring installed in the brake housing. The static plate and the dynamic plate are alternately stacked axially and are compressed as the service brake piston pushes. The return spring is compressed as the static plate and the dynamic plate are compressed. The brake disc spring is axially installed between the parking brake piston and the rear end cover, and is composed of multiple disc springs stacked in sequence.

[0016] Preferably, the rear end of the input shaft extends out of the box and is coaxially connected to the internal meshing rotor pump, the shell of the internal meshing rotor pump is fixed to the box, the front end of the box is equipped with a flange seat that can be connected to the power source equipment, and the front end of the input shaft extends out of the box and into the flange seat.

[0017] The beneficial effects of the utility model are:

[0018] The utility model is a power shift gearbox for a harvester, and the second and third gear clutches and the first gear clutch are all wet multi-plate clutches. The engagement and disengagement of the clutches are achieved through electro-hydraulic control, which can realize shifting without power interruption during operation, thereby improving adaptability and operating performance; the differential lock adopts an electro-hydraulic controlled wet multi-plate differential lock, which can realize the non-stop differential locking function, making it easier to get out of a stuck vehicle, with higher ground adaptability and passing performance, and can control the maximum vehicle speed at which the differential lock is activated, preventing the differential lock from being activated at high speeds, making the differential lock operation safer; the use of wet multi-plate brakes replaces the existing The mechanical control is improved to electro-hydraulic control, which makes the driving experience more comfortable and reliable, and improves the braking comfort. The integrated parking and driving structure can effectively reduce the space volume of the brake, improve the structural compactness and integration, and reduce the space occupancy rate of the gearbox. The wet multi-disc brake has high braking efficiency, fast heat dissipation, small friction plate wear and longer service life; the gear clutch, differential lock and brake all adopt an electro-hydraulic controlled multi-disc wet structure, which improves the harvester's handling performance and work efficiency, making the gearbox suitable for long-distance driving and heavy-load work, with strong durability and high adaptability to road conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a schematic diagram of the power shift gearbox of the harvester of the present utility model.

[0020] Figure 2 for Figure 1 A partially enlarged schematic diagram of the location of the third-gear clutch.

[0021] Figure 3 for Figure 1 A partially enlarged schematic diagram of the location of the first gear clutch.

[0022] Figure 4 for Figure 1 A partially enlarged schematic diagram of the location of the center differential lock.

[0023] Figure 5 A schematic diagram of the brake. DETAILED DESCRIPTION

[0024] The following combination Figures 1 to 5 The embodiments of the present utility model are described in detail.

[0025] The power shift gearbox of the harvester includes a housing 1, an input shaft 2 installed in the housing 1, an intermediate shaft 3 parallel to the input shaft 2, a differential 4 connected to the intermediate shaft 3, and a half shaft 5 splined to the half shaft gears of the differential 4 and parallel to the intermediate shaft 3. A second and third gear clutch 6 is installed on the input shaft 2, and a first gear clutch 7 is installed on the intermediate shaft 3. The input shaft 2 drives the intermediate shaft 3 and the differential 4 to move with the engagement of the second and third gear clutch 6 or the first gear clutch 7. The feature is that: two half shafts 5 are respectively equipped with brakes 8 fixed to the housing, and one half shaft 5 is equipped with a differential lock 9 fixed to the differential 4. The second and third gear clutches 6 and the first gear clutch 7 are both wet multi-plate clutches controlled by electro-hydraulic control, the brake 8 is a wet multi-plate brake controlled by electro-hydraulic control and adopts an integrated parking and driving function, and the differential lock 9 is a wet multi-plate differential lock controlled by electro-hydraulic control.

[0026] The power shift gearbox of the harvester described above, the second and third gear clutches 6 and the first gear clutch 7 are all wet multi-plate clutches, which realize the engagement and separation of the clutches through electro-hydraulic control, and can realize shifting without power interruption during operation, thereby improving adaptability and operational performance; the differential lock 9 adopts an electro-hydraulic controlled wet multi-plate differential lock, which can realize the non-stop differential locking function, making it easier to get out of a stuck vehicle, with higher ground adaptability and passing performance, and can control the maximum vehicle speed at which the differential lock 9 is activated, preventing the differential lock from being activated at high speeds, and making the differential lock operation safer; a wet multi-plate brake is used to The existing mechanical control has been improved to electro-hydraulic control, making the driving experience more comfortable and reliable, and improving braking comfort. The integrated parking and driving structure can effectively reduce the space volume of the brake, improve the structural compactness and integration, and reduce the space occupancy rate of the gearbox. The wet multi-disc brake has high braking efficiency, fast heat dissipation, small friction plate wear, and longer service life; the gear clutch, differential lock and brake all adopt an electro-hydraulic controlled multi-disc wet structure, which improves the harvester's handling performance and work efficiency, making the gearbox suitable for long-distance driving and heavy-load work, with strong durability and high adaptability to road conditions.

[0027] The second gear driving gear 21 and the third gear driving gear 22 are rotatably mounted on the input shaft 2, the second gear driven gear 31 meshing with the second gear driving gear 21 and the third gear driven gear 32 meshing with the third gear driving gear 22 are fixed on the intermediate shaft 3, the second and third gear clutch 6 is arranged between the second gear driving gear 21 and the third gear driving gear 22, and includes a second and third gear housing 61 fixed coaxially with the input shaft 2, and a second gear piston 62 and a second gear friction wheel corresponding to the second gear piston 62 are installed in the second and third gear housing 61. The wipe plate group 63, the third-speed piston 64 and the third-speed friction plate group 65 corresponding to the third-speed piston 64, the second-speed piston 62 and the third-speed piston 64 respectively form piston chambers for high-pressure oil to enter the second- and third-speed housings 61, and an oil path connected to the piston chambers is provided on the input shaft 2. The second-speed friction plate group 63 is pressed by the second-speed piston 62 to combine the second-speed driving gear 21 with the second- and third-speed housings 61, and the third-speed friction plate group 65 is pressed by the third-speed piston 64 to combine the third-speed driving gear 22 with the second- and third-speed housings 61. The second gear driving gear 21 and the third gear driving gear 22 can rotate relative to the input shaft 2. When the second gear piston 62 does not press the second gear friction plate group 63 and the third gear piston 64 does not press the third gear friction plate group 65, the power of the input shaft 2 will not be transmitted to the intermediate shaft 2 through the second gear driving gear 21 or the third gear driving gear 22. The second and second gear housing 61 is fixed to the input shaft 2. When the second gear piston 62 presses the second gear friction plate group 63, the second gear driving gear 21 is combined with the second and third gear housing 61, and the second gear driving gear 21 will rotate with the input shaft 2. The synchronous rotation transmits power to the second gear driven gear 31, thereby driving the intermediate shaft 3 to rotate; when the third gear piston 64 presses the third gear friction plate group 65, the third gear driving gear 22 is combined with the second and third gear housings 61, and the third driving wheel 22 will input the shaft 2 to rotate synchronously to transfer power to the third gear driven gear 32, thereby driving the intermediate shaft 3 to rotate. The second gear friction plate group 63 and the third gear friction plate group 65 cannot be pressed at the same time. The second gear or third gear power transmission of the transmission is realized through the movement of the second gear piston 62 or the third gear piston 64.

[0028] Among them, the second gear friction plate group 63 is installed between the second and third gear housing 61 and the second gear driving gear 21, and the third gear friction plate assembly 65 is installed between the second and third gear housing 61 and the third gear driving gear 22. The second gear friction plate group 63 and the third gear friction plate group 65 have the same structure, both of which include a housing friction plate 66 positioned on the second and third gear housing 61 and a gear friction plate 67 splined with the third gear driving gear 22 or the second gear driving gear 21. The gear friction plate 67 and the housing friction plate 66 are alternately arranged along the axial direction. The second-gear disc spring 68 and the third-gear disc spring 69 are respectively positioned on the input shaft 2 and are composed of multiple disc springs stacked in sequence. The second-gear disc spring 68 is compressed as the second-gear piston 62 presses the second-gear friction plate group 63, and the third-gear disc spring 69 is compressed as the third-gear piston 64 presses the third-gear friction plate group 65. When the second-gear piston 62 and the third-gear piston 64 do not apply pressure to the corresponding friction plate group, the gear friction plate 67 and the housing friction plate 66 do not generate friction in the oil, and the rotation of the input shaft 2 will not drive the second-gear driving gear 21 or the third-gear driving gear 22 to rotate. When the second-gear piston 62 presses the housing friction plate 66 and the gear friction plate 67 in the second-gear friction plate group 63 or the third-gear piston 64 presses the housing friction plate 66 and the gear friction plate 67 in the third-gear friction plate group 65, because the housing friction plate 66 is positioned in the second- and third-gear housing 61 and the gear friction plate 67 is splined with the second-gear driving gear 21 or the third-gear driving gear 22, the housing friction plate 66 rotates synchronously with the input shaft 2. It drives the gear friction plate 67 to rotate synchronously, so that the second-gear driving gear 21 or the third-gear driving gear 22 rotates synchronously with the input shaft 2, realizing the engagement of the second-gear and third-gear clutches 6, so that the power of the input shaft 2 is transmitted to the intermediate shaft 3 through the second-gear driving gear 21 or the third-gear driving gear 22. The second-gear disc spring 68 is used for the return movement of the second-gear piston 62, and the third-gear disc spring 69 is used for the return movement of the third-gear piston 64. The elastic restoring force of the disc springs pushes the corresponding pistons to move back. For example, when the output power of the transmission is shifted from the second gear to the third gear, the return movement of the second-gear piston 62 and the pressing of the third-gear piston 64 on the third-gear friction plate group 65 are precisely controlled, which can realize gear shifting without power interruption in the workplace, thereby improving gear shifting comfort and operating performance.

[0029] Among them, the first gear driving gear 23 is integrally formed on the input shaft 2, and the first gear driven gear 33 meshing with the first gear driving gear 23 is rotatably installed on the intermediate shaft 3. The first gear clutch 7 includes a first gear housing 71 coaxially fixed to the intermediate shaft 3, and the first gear housing 71 is equipped with a first gear piston 72 and a first gear friction plate group 73 corresponding to the first gear piston 72. A piston cavity for high-pressure oil to enter is formed between the first gear piston 72 and the intermediate shaft 3, and an oil path connected to the piston cavity is opened on the intermediate shaft 3. The first gear friction plate group 73 presses the first gear piston 72 to move the first gear. The first gear driven gear 33 is combined with the first gear housing 71. The first gear friction plate group 73 has the same structure as the second gear friction plate group 63, including a housing friction plate 66 positioned on the first gear housing 71 and a gear friction plate 67 splined with the first gear driven gear 33. The housing friction plate 66 and the gear friction plate 67 are pressed together by the push of the first gear piston 72. The first gear housing 71 is equipped with a first gear disc spring 74 corresponding to the first gear piston 2. The first gear disc spring 74 has the same structure as the second gear disc spring 68 and is compressed as the first gear piston 72 presses the first gear friction plate group 73. When the first gear piston 72 in the first gear clutch 7 does not press the first gear friction plate group 73, the first gear driven gear 33 can only rotate on the intermediate shaft 3, and the power of the first gear driving gear 23 cannot be transmitted to the intermediate shaft 3. When the first gear piston 72 presses the first gear friction plate group 73, the gear friction plates and the housing friction plates in the first gear friction plate group 73 are pressed tightly, and the housing friction plates are positioned in the first gear housing 71. The gear friction plates and the first gear driven gear 33 are spline-matched. The pressing of the two will combine the first gear housing 71 with the first gear driven gear 33, and the first gear housing 71 is fixed to the intermediate shaft, so that the first gear driven gear 33 can rotate synchronously with the intermediate shaft 3, effectively The first gear clutch 7 is engaged, so that the power of the input shaft 2 is transmitted to the first gear driven gear 33 through the first gear driving gear 23 to drive the intermediate shaft 3 to rotate; the second and third gear clutch 6 realizes the second gear or third gear power transmission, and the first gear clutch 7 realizes the first gear power transmission. The second gear piston or the third gear piston in the second and third gear clutch 6 presses the corresponding friction plate group to realize the engagement of the corresponding gear driving gear and the input shaft 2, and the first gear driven gear and the intermediate shaft 3 are realized by pressing the first gear friction plate group by the first gear piston in the first gear clutch 7. By accurately controlling the movement of the corresponding gear piston through electro-hydraulic control during shifting, gear shifting without power interruption can be realized.

[0030] Among them, the intermediate shaft 3 is integrally formed with a secondary constant mesh driving gear 34, and the differential case of the differential 4 is fixed with a secondary constant mesh driven gear 41 that meshes with the secondary constant mesh driving gear 34. The differential lock 9 includes a differential lock gear 91 coaxially fixed to the half-shaft 5, a differential lock housing 92 fixed to the differential housing, a differential lock piston 93 movably mounted in the differential lock housing 92, and a differential lock friction plate group 94 mounted in the differential lock housing 92 and corresponding to the differential lock piston 93. The differential lock housing 92 is provided with an oil circuit for high pressure to enter and drive the differential lock piston 93 to move. The differential lock friction plate group 94 combines the differential lock gear 91 with the differential lock housing 92 as the differential lock piston 93 is pressed. The secondary constant mesh driving gear 34 on the intermediate shaft 3 drives the secondary constant mesh driven gear 41 to rotate, transmitting power to the differential 4, and the power is transmitted from the differential 4 to the half shaft 5, driving the wheels connected to the half shaft 5 to rotate, realizing power output. Under normal driving conditions, the differential lock piston 93 does not press the differential lock friction plate group 94, and the harvester can realize normal differential function. When the differential function needs to be locked, high-pressure oil is pumped into the differential lock housing to push the differential lock piston 93 to press the differential lock friction plate group 94, so that the differential lock gear 91 and the differential lock housing 9 2, the differential lock gear 91 is fixed on the half-shaft 5, and the differential lock housing 92 is fixed to the differential case of the differential 4, forming a combination of the differential case and the half-shaft 5 into a whole, realizing the locking of the differential function, making the torque output by the two half-shafts the same and the speed synchronized, effectively reducing the probability of getting stuck, improving the ground adaptability and passability of the harvester, and pressing the differential lock friction plate group 94 through electro-hydraulic control of the differential lock piston 93, not only making the operation of getting out of the stuck vehicle simpler, but also controlling the maximum speed of the differential lock to prevent the differential lock from being activated at high speed, and making the differential lock operation safer.

[0031] Among them, the differential lock friction plate group 94 includes a friction plate 1 95 positioned in the differential lock housing 92, a friction plate 2 96 splined on the differential lock gear 91, and a differential lock spring 97 installed in the differential lock housing 92. The friction plate 1 95 and the friction plate 2 96 are alternately arranged in the axial direction and are compressed as the differential lock piston 93 pushes them. The differential lock spring 97 is compressed as the friction plate 1 95 and the friction plate 2 96 are compressed. When the differential lock piston 93 does not apply pressure to the differential lock friction plate group 94, friction plate 1 95 and friction plate 2 96 do not generate friction in the oil. When friction plate 1 95 and friction plate 2 96 are pressed by the push of the differential lock piston 93, friction plate 1 95 is positioned in the differential lock housing 92, friction plate 2 96 is splined with the differential lock gear 91, the differential lock housing 92 is fixed to the differential case of the differential 4, and the differential lock gear 91 is fixed to the half-shaft 5, so that one side of the half-shaft is combined with the differential 5 into a whole, so that the differential function of the half-shafts 5 on both sides is locked, and the half-shafts 5 on both sides output the same torque and the same speed, thereby avoiding slipping of the wheels on one side, improving the passability of the harvester on muddy and pitted roads, and improving the harvester's adaptability to road conditions.

[0032] The brake 8 includes a brake housing 81 fixed to the housing 1. The brake housing 81 contains a brake gear 82 fixed coaxially to the half-shaft 5, a service brake piston 83, a parking brake piston 84 abutting against the service brake piston 83, a brake friction plate group 85 corresponding to the service brake piston 83, and a brake disc spring 86 cooperating with the parking brake piston 84. The front end of the brake housing 81 is sealed with the housing 1, and the rear end is sealed by a rear cover end 87. The rear cover end 87 is rotatably mounted on the half-shaft 5. The parking brake piston 84 and the service brake piston 83 respectively form piston cavities with the brake housing 81 for high-pressure oil to enter, and an oil path connected to the piston cavity is opened on the brake housing 81. The brake disc spring 86 pushes the parking brake piston 84 to press the service brake piston 83 and the brake friction plate group 85 in turn to combine the brake gear 82 with the brake housing 81. Figure 5 As shown, the parking brake piston 84 is against the service brake piston 83. When parking, the brake disc spring 86 presses the parking brake piston 84, the service brake piston 83 and the brake friction plate group 85 in sequence, so that the brake gear 82 is combined with the brake housing 81. Since the brake housing 81 is fixed to the box body 1 and cannot rotate, the brake gear 82 is coaxially fixed to the half shaft 5 and will rotate synchronously with the half shaft. Therefore, the half shaft 5 cannot rotate when parking.

[0033] Among them, the brake friction plate group 85 includes a static plate 88 positioned on the brake housing 81, a dynamic plate 89 that cooperates with the spline on the brake gear 82, and a return spring 80 installed in the brake housing 81. The static plate 88 and the dynamic plate 89 are alternately stacked along the axial direction and are compressed as the service brake piston 83 pushes them. The return spring 80 is compressed as the static plate 88 and the dynamic plate 89 are compressed. The brake disc spring 86 is axially installed between the parking brake piston 84 and the rear end cover 87, and is composed of multiple disc springs stacked in sequence. The static plate 88 is positioned on the brake housing 81. The brake housing 81 is fixed to the car body and cannot rotate, so that the static plate 88 cannot rotate. The dynamic plate 89 and the brake 82 are splined together and will rotate synchronously with the half-shaft 5. When the dynamic plate 89 and the static plate 88 are not pressed tightly, the dynamic plate 89 and the static plate 88 do not generate friction in the oil and will not affect the normal rotation of the half-shaft 5. When the dynamic plate and the static plate are pressed tightly, the half-shaft 5 and the brake housing 81 are combined together and cannot rotate, thereby achieving braking. When the vehicle stops, the brake disc spring 86 pushes the parking brake piston 84 to press the service brake piston 83, so that the service brake piston 83 presses the static plate 88 and the dynamic plate 89, thereby combining the brake housing 81 with the half shaft 5 to achieve parking brake; when the harvester starts, hydraulic oil is pumped into the piston cavity corresponding to the parking brake piston 84, and the parking brake piston 84 pushes the brake disc spring 86 to compress and separate from the service brake piston 83, releasing the pressure on the service brake piston 83. At the same time, the return spring 80 pushes the service brake piston 83 to move back to the side of the parking brake piston 84, eliminating the pressure on the brake friction plate group 85. Tighten, the movable plate 88 and the static plate 89 separate due to the disappearance of the pressing force, and the parking brake is released; when the driver steps on the brake pedal, hydraulic oil is pumped into the piston chamber corresponding to the service brake piston 83, and the hydraulic oil pushes the service brake piston 83 to compress the static plate 88 and the movable plate 89, combining the brake housing 81 and the half-shaft 5 together to achieve service braking; when the engine is turned off or the parking button is pressed, the hydraulic oil in the piston chamber corresponding to the parking brake piston 84 is depressurized, and under the action of the rebound force of the brake disc spring 86, the parking brake piston 84 pushes the service brake piston 83 again to compress the movable plate 88 and the movable plate 89 to achieve parking braking. The wet multi-disc brake is adopted, and the existing mechanical control is improved to electro-hydraulic control, making the driving experience more comfortable and reliable, and improving the braking comfort. The integrated parking and driving structure can effectively reduce the space volume of the brake, improve the structural compactness and integration, and reduce the space occupancy rate of the gearbox. The wet multi-disc brake has high braking efficiency, fast heat dissipation, small friction plate wear, and longer service life; the gear clutch, differential lock and brake all adopt an electro-hydraulic controlled multi-disc wet structure, which improves the harvester's handling performance and work efficiency, making the gearbox suitable for long-distance driving and heavy-load work, with strong durability and high adaptability to road conditions.

[0034] The rear end of the input shaft 2 extends out of the housing 1 and is coaxially connected to an internal meshing rotor pump 10. The housing of the internal meshing rotor pump 10 is fixed to the housing. The internal meshing rotor pump 10 and the input shaft 2 rotate synchronously to pump the liquid in the housing 1 into the bearings on the input shaft 2, achieving active lubrication of the bearings. The front end of the housing 1 is equipped with a flange seat 11 that can be connected to a power source device. The front end of the input shaft 2 extends out of the housing and into the flange seat. The power source device is a hydraulic motor or an electric motor. The front end of the input shaft 2 extends into the flange seat and connects to the power source device to input power to the transmission.

[0035] The above is a complete description of the technical solutions of the embodiments of the present invention in conjunction with the accompanying drawings. It should be noted that the embodiments described are only part of the embodiments of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

Claims

1. A power shift transmission for a harvester, comprising a housing, an input shaft mounted in the housing, an intermediate shaft parallel to the input shaft, a differential connected to the intermediate shaft, and half shafts spline-connected to the differential half shaft gears and parallel to the intermediate shaft. The input shaft is equipped with a second and third gear clutch, and the intermediate shaft is equipped with a first gear clutch. The input shaft drives the intermediate shaft and differential to move when the second and third gear clutch or the first gear clutch is engaged. The characteristics of the transmission are: The two half-axles are respectively equipped with brakes fixed to the case, and one half-axle is equipped with a differential lock fixed to the differential. The second and third gear clutches and the first gear clutch are all wet multi-plate clutches controlled by electro-hydraulic control. The brakes are wet multi-plate brakes controlled by electro-hydraulic control and adopt integrated parking and driving functions. The differential lock is a wet multi-plate differential lock controlled by electro-hydraulic control.

2. The power shift gearbox for a harvester according to claim 1, characterized in that: The second-speed driving gear and the third-speed driving gear are rotatably mounted on the input shaft, and the second-speed driven gear meshing with the second-speed driving gear and the third-speed driven gear meshing with the third-speed driving gear are fixed on the intermediate shaft. The second-speed and third-speed clutches are arranged between the second-speed driving gear and the third-speed driving gear, and include a second-speed and third-speed housing coaxially fixed to the input shaft, a second-speed piston, a second-speed friction plate group corresponding to the second-speed piston, a third-speed piston, and a third-speed friction plate group corresponding to the third-speed piston are mounted in the second-speed and third-speed housings, piston cavities for high-pressure oil to enter are respectively formed between the second-speed piston and the third-speed piston and the second-speed and third-speed housings, and an oil path connected to the piston cavity is provided on the input shaft. The second-speed friction plate group combines the second-speed driving gear with the second-speed and third-speed housings as the second-speed piston is pressed, and the third-speed friction plate group combines the third-speed driving gear with the second-speed and third-speed housings as the third-speed piston is pressed.

3. The power shift gearbox for a harvester according to claim 2, characterized in that: The second-gear friction plate is assembled between the second- and third-gear housing and the second-gear driving gear, and the third-gear friction plate is assembled between the second- and third-gear housing and the third-gear driving gear. The second-gear friction plate group and the third-gear friction plate group have the same structure, both including housing friction plates positioned on the second- and third-gear housings and gear friction plates splined with the third-gear driving gear or the second-gear driving gear. The gear friction plates and the housing friction plates are alternately arranged along the axial direction and are compressed as the second-gear piston or the third-gear piston pushes them. The input shaft is equipped with a second-gear disc spring corresponding to the second-gear piston and a third-gear disc spring corresponding to the third-gear piston. The second-gear disc spring and the third-gear disc spring are respectively positioned on the input shaft and are both composed of multiple disc springs stacked in sequence. The second-gear disc spring is compressed as the second-gear piston presses the second-gear friction plate group, and the third-gear disc spring is compressed as the third-gear piston presses the third-gear friction plate group.

4. The power shift gearbox for a harvester according to claim 3, characterized in that: The first gear driving gear is integrally formed on the input shaft, and the first gear driven gear meshing with the first gear driving gear is rotatably installed on the intermediate shaft. The first gear clutch includes a first gear housing coaxially fixed on the intermediate shaft, a first gear piston and a first gear friction plate group corresponding to the first gear piston are installed in the first gear housing, a piston chamber for high-pressure oil to enter is formed between the first gear piston and the intermediate shaft, and an oil passage connected to the piston chamber is provided on the intermediate shaft. The first gear friction plate group combines the first gear driven gear with the first gear housing as the first gear piston is pressed. The first gear friction plate group has the same structure as the second gear friction plate group, including a housing friction plate positioned on the first gear housing and a gear friction plate splined with the first gear driven gear. The housing friction plate and the gear friction plate are compressed as the first gear piston pushes. The first gear housing is equipped with a first gear disc spring corresponding to the first gear piston. The first gear disc spring has the same structure as the second gear disc spring and is compressed as the first gear piston presses the first gear friction plate group.

5. The power shift gearbox for a harvester according to claim 1, characterized in that: A secondary constant mesh driving gear is integrally formed on the intermediate shaft, and a secondary constant mesh driven gear meshing with the secondary constant mesh driving gear is fixed on the differential case of the differential. The differential lock includes a differential lock gear coaxially fixed on the half-shaft, a differential lock housing fixed to the differential housing, a differential lock piston movably installed in the differential lock housing, and a differential lock friction plate group installed in the differential lock housing and corresponding to the differential lock piston. An oil circuit for high pressure to enter and drive the differential lock piston to move is provided on the differential lock housing. The differential lock friction plate group combines the differential lock gear with the differential lock housing as the differential lock piston is pressed.

6. The power shift gearbox for a harvester according to claim 5, characterized in that: The differential lock friction plate group includes a friction plate 1 positioned in the differential lock housing, a friction plate 2 splined on the differential lock gear, and a differential lock spring installed in the differential lock housing. The friction plate 1 and the friction plate 2 are alternately arranged along the axial direction and are compressed as the differential lock piston pushes. The differential lock spring is compressed as the friction plate 1 and the friction plate 2 are compressed.

7. The power shift gearbox for a harvester according to claim 1, characterized in that: The brake includes a brake housing fixed to the housing, in which are installed a brake gear coaxially fixed to the half-shaft, a service brake piston, a parking brake piston abutting the service brake piston, a brake friction plate group corresponding to the service brake piston, and a brake disc spring cooperating with the parking brake piston. The front end of the brake housing is sealed with the housing, and the rear end is sealed through the rear cover end, and the rear cover end is rotatably mounted on the half-shaft. The parking brake piston and the service brake piston respectively form piston chambers with the brake housing for high-pressure oil to enter, and an oil path connected to the piston chamber is opened on the brake housing. The brake disc spring pushes the parking brake piston to press the service brake piston and the brake friction plate group in turn to combine the brake gear with the brake housing.

8. The power shift gearbox for a harvester according to claim 7, characterized in that: The brake friction plate group includes a static plate positioned on the brake housing, a dynamic plate that fits on the brake gear with a spline, and a return spring installed in the brake housing. The static plate and the dynamic plate are alternately stacked axially and are compressed as the service brake piston pushes. The return spring is compressed as the static plate and the dynamic plate are compressed. The brake disc spring is axially installed between the parking brake piston and the rear end cover, and is composed of multiple disc springs stacked in sequence.

9. The power shift gearbox for a harvester according to claim 1, characterized in that: The rear end of the input shaft extends out of the box and is coaxially connected to the internal meshing rotor pump. The shell of the internal meshing rotor pump is fixed to the box. The front end of the box is equipped with a flange seat that can be connected to the power source equipment. The front end of the input shaft extends out of the box and into the flange seat.

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