Transmission structure of tractor gearbox

Abstract

The tractor gearbox transmission structure comprises a gearbox body, an input shaft and an output shaft, the input shaft sequentially and coaxially penetrates through a reverse gear driving gear and a synchronizer from left to right, the right end of the input shaft and the right end of a first shaft are coaxially installed through a bearing, and the left end of the output shaft is coaxially arranged in a right end hole of a second shaft in a sleeved mode. The other end of the output shaft is provided with a shaft check ring between the middle-gear driven gear and the bearing, and the left end, provided with the check ring, of the output shaft sequentially and coaxially penetrates through the middle-gear driven gear, the low-gear driven gear, the high-low-gear meshing seat and the high-low-gear meshing sleeve from right to left. Compared with similar products, a pair of normally meshed gears is saved, and the number of gears used for main speed change and auxiliary speed change is the smallest than that of the similar products; the working gear configuration density of the gear is large and reasonable; the reverse intermediate gear of the transmission structure adopts a duplicate gear structure, and is compact in structure, fewer in parts, lower in cost, simple to assemble and convenient to maintain.

Description

Technical Field

[0001] The utility model relates to the technical field of tractor gearboxes, in particular to a transmission structure of a tractor gearbox. Background Art

[0002] Fig. 9 This is a schematic diagram of the transmission mechanism of a certain type of tractor gearbox. This gearbox is suitable for tractors with 80 to 110 horsepower. Its main transmission system features: 4×3 shuttle shifting and clutch sleeve shifting. The main defects and shortcomings of this gearbox are:

[0003] 1. The number of gears is limited, and only 12+12 shuttle shifting can be achieved. The crawler gear uses planetary gear reduction, which has a complex structure and high cost;

[0004] 2. All gearboxes use straight gear transmission, which limits the transmission efficiency;

[0005] 3. The mechanical main transmission adopts the traditional clutch sleeve shifting, which makes the gear shifting not smooth and easy to get stuck;

[0006] 4. To realize 4×3 gears (i.e. 4 main gears (1st, 2nd, 3rd, 4th gears), 3 auxiliary gears (high, medium, low gears), and no reverse gear), 7 pairs of gears are required (the total number of gears is 13), which is a large number of gears.

[0007] Fig.10 The present invention is a schematic diagram of the reverse transmission of a certain type of existing tractor gearbox. The disadvantages of the present invention are that the present invention has many parts, high processing and assembly costs, and inconvenient maintenance. Utility Model Content

[0008] The utility model aims to provide a tractor gearbox transmission structure to overcome the above problems or at least partially solve the above problems.

[0009] In order to achieve the above-mentioned purpose, the technical solution of the utility model is specifically implemented as follows:

[0010] The utility model provides a tractor gearbox transmission structure, comprising a gearbox body, wherein the gearbox body is provided with a power output front section shaft, an input shaft, an input bearing seat, a reverse gear driving gear, a synchronizer, a first shaft, a first gear driving gear, a second gear driving gear, a third gear driving gear, a secondary speed change double gear, a middle gear meshing sleeve, a middle gear meshing tooth seat, a middle gear driving gear, an upper end cover, a crawler gear double gear, a connecting sleeve, a power output rear section shaft, a crawler gear meshing sleeve, a crawler gear meshing seat, an output shaft, a small bevel gear shaft, a crawler gear passive gear, a direct gear meshing seat, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a middle gear meshing sleeve, a crawler gear meshing seat, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a lower end cover, a middle gear passive gear, a middle gear passive gear, a middle gear meshing sleeve, a crawler gear meshing seat, a lower end cover, a middle gear passive gear ... Gears, low gear driven gears, high and low gear meshing seats, high and low gear meshing sleeves, fourth gear driven gears, second shaft, third gear driven gears, second gear driven gears, first gear driven gears, reverse gear double gears, reverse gear intermediate shaft and second shaft front end cover. The gearbox body is also provided with four walls, namely box wall one, box wall two, box wall three and box wall four, and the gearbox body is divided into four cavities, namely gearbox cavity one, gearbox cavity two, gearbox cavity three and gearbox cavity four, and three groups of holes are provided in parallel on the vertical wall, namely group hole one, group hole two and group hole three.

[0011] The input shaft is arranged on the first box wall and passes through a group hole in the first and second gearbox cavities. The input shaft coaxially passes through the reverse gear driving gear and the synchronizer from left to right in sequence. The right end of the input shaft is coaxially installed with the right end of the first shaft through a bearing. The inner hole of the synchronizer is spline-engaged with the input shaft. The inner hole of the reverse gear driving gear is coaxially sleeved on the input shaft. The input bearing seat is coaxially installed on the left end of the input shaft. One end of the input bearing seat is fixed to the first box wall by bolts for axial limiting the left end of the input shaft. The reverse gear driving gear is meshed with one end of the reverse gear duplex gear. The reverse gear duplex gear is coaxially sleeved on the reverse gear intermediate shaft through a bearing. The reverse gear intermediate shaft is arranged at three group holes in the second gearbox cavity formed by the first box wall and the second box wall.

[0012] The one shaft is arranged at a group hole in the gearbox cavity three formed by the second and third box walls. The one shaft coaxially passes through the first gear driving gear, the second gear driving gear, the third gear driving gear and the synchronizer from left to right in sequence. The right end of the one shaft is coaxially installed with the left end of the auxiliary speed change double gear through a bearing. The first gear driving gear, the second gear driving gear and the inner hole of the synchronizer are spline-engaged with the one shaft, and the third gear driving gear is loosely sleeved on the one shaft.

[0013] One end of the crawler gear double gear is coaxially mounted with one end of the auxiliary speed change double gear through a bearing.

[0014] The auxiliary speed-changing double gear is arranged at a group hole in the gearbox cavity four formed by the box wall three and the box wall four. One end of the auxiliary speed-changing double gear is arranged in the gearbox cavity three, and coaxially passes through the middle gear meshing gear seat, the middle gear meshing sleeve, the middle gear driving gear and the upper end cover from left to right. The upper end cover is fixed to the box wall four by bolts and is used for axial limiting the right end of the auxiliary speed-changing double gear. The inner hole of the middle gear driving gear is coaxially sleeved on the auxiliary speed-changing double gear, and the inner hole of the middle gear meshing gear seat is spline-engaged with the auxiliary speed-changing double gear.

[0015] The output shaft is arranged at two sets of holes in the transmission cavity four formed by the box wall three and the box wall four. The left end of the output shaft is coaxially sleeved in the right end hole of the two shafts. The other end of the output shaft is installed with a shaft retaining ring between the middle gear driven gear and the bearing. The left end of the output shaft mounting retaining ring coaxially passes through the middle gear driven gear, the low gear driven gear, the high and low gear meshing seat and the high and low gear meshing sleeve from right to left in sequence, and the right end of the output shaft mounting retaining ring coaxially passes through the lower end cover and the direct gear meshing seat from left to right in sequence. The lower end cover is fixed to the box wall four by bolts and is used for axial limiting the rear end of the output shaft. The inner holes of the high and low gear meshing seat, the middle gear driven gear and the direct gear meshing seat are all spline meshed with the output shaft. The inner hole of the high and low gear meshing sleeve is spline meshed with the high and low gear meshing seat, and the inner hole of the low gear driven gear is empty sleeved on the output shaft.

[0016] The front end cover of the second shaft is coaxially sleeved in the second group hole, one end of which is fixed to the first wall of the box body by bolts, and the other end contacts one end of the leftmost bearing of the second shaft, which is used for axial limitation of the front end of the second shaft.

[0017] The two shafts are arranged at the second group of holes in the transmission cavity three formed by the second and third box walls. The two shafts coaxially pass through the fourth gear driven gear, the third gear driven gear, the second gear driven gear, the synchronizer and the first gear driven gear from right to left in sequence and are locked with a locking nut. The fourth gear driven gear, the third gear driven gear and the inner holes of the synchronizer are all spline-engaged with the two shafts. The second gear driven gear and the first gear driven gear are both loosely sleeved on the two shafts.

[0018] As a further solution of the utility model, the inner holes of the second gear driven gear and the first gear driven gear are coaxially sleeved with a bushing, a needle roller bearing and a needle roller bearing retaining ring.

[0019] As a further solution of the utility model, needle bearings are also provided in the holes at the left end of the output shaft and the right end of the second shaft, and are supported by the needle bearings.

[0020] As a further solution of the utility model, the right end of the crawler gear double gear is coaxially installed with the rear axle case through a bearing, and the rear axle case is fixedly connected to the right side of the gearbox body.

[0021] As a further solution of the utility model, a small bevel gear shaft is arranged inside the rear axle case through a bearing, and the small bevel gear shaft is coaxially arranged at the tail end of the output shaft. The small bevel gear shaft coaxially passes through the crawler gear engagement seat and the crawler gear driven gear from left to right in sequence, and the crawler gear engagement seat is spline-engaged with one end of the small bevel gear shaft. The crawler gear engagement seat is arranged on one side of the direct gear engagement seat and is connected through a crawler gear engagement sleeve.

[0022] As a further solution of the utility model, the power output front section shaft coaxially passes through the inner hole of the input shaft, the inner hole of the first shaft, and the inner hole of the auxiliary speed double gear, and the power output rear section shaft coaxially passes through the inner hole of the crawler gear double gear, and the power output front section shaft and the power output rear section shaft are connected in the inner hole of the crawler gear double gear through a connecting sleeve.

[0023] The utility model provides a tractor gearbox transmission structure, which has the following beneficial effects:

[0024] 1. The reverse gear and main transmission adopt synchronizer shifting, which has fast shifting and smooth combination, effectively reducing the shifting impact. The reverse gear is placed before the main transmission, and the synchronizer synchronous inertia in the main transmission area is small;

[0025] 2. The reverse gear intermediate gear of this transmission structure adopts a double gear structure, which has a compact structure, fewer parts, lower cost, simple assembly and convenient maintenance;

[0026] 3. Use common gears to reduce the use of gears and reduce gear oil stirring;

[0027] 4. The main and auxiliary speed change can realize 12F+12R gears, and the crawler gear can be optionally installed to realize more gear shifting. The gear working gears are distributed according to a certain level ratio. The gear configuration density is large and reasonable. The highest speed gear has a high speed, which is convenient for cross-zone operation.

[0028] 5. The self-developed (1+1)×4×3 structure 12F+12R gearbox has an advanced and original structure. Compared with similar products, it saves a pair of constantly meshed gears, and the number of gears used for main and auxiliary speed changes is the smallest among similar products. That is, when the (1+1)4×3 gear number is realized (i.e., 4 gears for the main speed change (1, 2, 3, 4) and 3 gears for the auxiliary speed change (high, medium, low)), the existing gearbox requires 7 pairs of gears (a total of 13 gears); while the newly developed gearbox transmission structure only requires 6 pairs of gears (a total of 11 gears). It has an advanced and original structure, and saves a pair of constantly meshed gears compared with similar products. The number of gears used for main and auxiliary speed changes is the smallest among similar products; the gear working gear position configuration density is large and reasonable. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In order to more clearly illustrate the technical solutions of the embodiments of the utility model, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the utility model. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0030] Figure 1 It is a structural schematic diagram of the utility model.

[0031] Figure 2 For this utility model Figure 1 Cross-sectional view at AA in the middle.

[0032] Figure 3 It is a structural schematic diagram of the gearbox body in the utility model.

[0033] Figure 4 For this utility model Figure 3 Cross-sectional view at AA in the middle.

[0034] Figure 5 It is the transmission route of the forward gear one gear lower in the utility model.

[0035] Figure 6 It is the transmission route of the reverse gear with one lower gear in the utility model.

[0036] Figure 7 It is the transmission route of the forward gear crawling high fourth gear in the utility model.

[0037] Figure 8 It is the transmission route of the reverse gear crawling high fourth gear in the utility model.

[0038] Fig. 9 It is a structural schematic diagram of the existing tractor gearbox transmission structure.

[0039] Fig.10 It is a structural schematic diagram of an existing reverse gear structure.

[0040] In the figure: 1. gearbox body; 2. power output front shaft; 3. input shaft; 4. input bearing seat; 5. reverse gear driving gear; 6. synchronizer; 7. first shaft; 8. first gear driving gear; 9. second gear driving gear; 10. third gear driving gear; 11. auxiliary speed change double gear; 12. middle gear meshing sleeve; 13. middle gear meshing gear seat; 14. middle gear driving gear; 15. upper end cover; 16. creeper gear double gear; 17. connecting sleeve;

[0041] 18. Power output rear shaft; 19. Crawler gear engagement sleeve; 20. Crawler gear engagement seat; 21. Output shaft;

[0042] 22. Small bevel gear shaft; 23. Crawler gear driven gear; 24. Direct gear engagement seat; 25. Lower end cover;

[0043] 26. Mid-gear passive gear; 27. Low-gear passive gear; 28. High- and low-gear engagement seat; 29. ​​High- and low-gear engagement sleeve; 30. Fourth-gear passive gear; 31. Second shaft; 32. Third-gear passive gear; 33. Second-gear passive gear; 34. First-gear passive gear; 35. Reverse gear double gear; 36. Reverse gear intermediate shaft; 37. Second shaft front end cover; 38. Box wall one; 39. Box wall two; 40. Box wall three; 41. Box wall four; 42. Transmission cavity one; 43. Transmission cavity two; 44. Transmission cavity three; 45. Transmission cavity four; 46. Group hole one; 47. Group hole two; 48. Group hole three. DETAILED DESCRIPTION

[0044] The exemplary embodiments of the present disclosure will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present disclosure are shown in the accompanying drawings, it should be understood that the present disclosure can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the present disclosure to those skilled in the art.

[0045] See also Figure 1-8 The utility model provides a tractor gearbox transmission structure, including a gearbox body 1, wherein the gearbox body 1 is provided with a power output front shaft 2, an input shaft 3, an input bearing seat 4, a reverse gear driving gear 5, a synchronizer 6, a first shaft 7, a first gear driving gear 8, a second gear driving gear 9, a third gear driving gear 10, a secondary speed change double gear 11, a middle gear meshing sleeve 12, a middle gear meshing gear seat 13, a middle gear driving gear 14, an upper end cover 15, a crawler gear double gear 16, a connecting sleeve 17, a power output rear shaft 18, a crawler gear meshing sleeve 19, a crawler gear meshing seat 20, an output shaft 21, a small bevel gear shaft 22, a crawler gear driven gear 23, Direct gear engagement seat 24, lower end cover 25, middle gear driven gear 26, low gear driven gear 27, high and low gear engagement seat 28, high and low gear engagement sleeve 29, fourth gear driven gear 30, second shaft 31, third gear driven gear 32, second gear driven gear 33, first gear driven gear 34, reverse gear double gear 35, reverse gear intermediate shaft 36 and second shaft front end cover 37. The gearbox body 1 is also provided with four walls, namely, box wall 1 38, box wall 2 39, box wall 3 40 and box wall 4 41, and the gearbox body 1 is divided into four cavities, namely, gearbox cavity 1 42, gearbox cavity 2 43, gearbox cavity 3 44 and gearbox cavity 4

[0046] 45, and three groups of holes are opened in parallel on the vertical wall, namely group hole 1 46, group hole 2 47 and group hole 3 48. The gearbox body 1 is also provided with oil seals, bearings, retaining rings, spacers, sleeves, bushings, O-rings, needle bearings, bolts, locking nuts, needle bearing retaining rings and shaft retaining rings.

[0047] The second shaft 31 is arranged at the second group hole 47 in the third gearbox cavity 44 composed of the second wall and the third box wall 40. The second shaft 31 passes through the bearing, the fourth gear passive gear 30, the shaft sleeve, the third gear passive gear 32, the second gear passive gear 33, the synchronizer 6, the first gear passive gear 34, the retaining ring, and the bearing from right to left in sequence, and then is locked with a locking nut. The inner holes of the fourth gear passive gear 30, the third gear passive gear 32, and the synchronizer 6 are all spline-engaged with the second shaft 31. The inner holes of the second gear passive gear 33 and the first gear passive gear 34 are coaxially sleeved with a bushing, a needle bearing, and a needle bearing retaining ring. The second gear passive gear 33 and the first gear passive gear 34 are sleeved on the second shaft 31.

[0048] The front end cover 37 of the second shaft is coaxially sleeved in the second hole group 47, one end of which is fixed to the box wall 1 38 by bolts, and the other end contacts one end of the leftmost bearing of the second shaft 31 for axial limitation of the front end of the second shaft 31.

[0049] The output shaft 21 is arranged at the group hole 2 47 in the gearbox cavity 4 45 composed of the box wall 3 40 and the box wall 4 41. The left end of the output shaft 21 is coaxially sleeved in the hole at the right end of the second shaft 31, and is supported by a needle bearing. The other end of the output shaft 21 is installed with a shaft retaining ring between the middle gear driven gear 26 and the bearing. The left end of the output shaft 21 mounting retaining ring coaxially passes through the middle gear driven gear 26, the sleeve, the retaining ring, the low gear driven gear 27, the high and low gear engagement seat 28, the high and low gear engagement sleeve 29, and the needle bearing from right to left. The right end of the output shaft 21 mounting retaining ring coaxially passes through the bearing, the lower end cover 25, the sleeve, the direct gear engagement seat 24, and the shaft retaining ring from left to right. The lower end cover 25 is fixed to the box wall 41 by bolts to limit the rear end of the output shaft 21 in the axial direction. The inner holes of the high and low gear engagement seat 28, the middle gear driven gear 26, and the direct gear engagement seat 24 are all splined with the output shaft 21. The inner hole of the high and low gear engagement sleeve 29 is splined with the high and low gear engagement seat 28. The inner hole of the low gear driven gear 27 is coaxially sleeved with a bushing, a needle bearing, and a needle bearing retaining ring, which is sleeved on the output shaft 21.

[0050] The auxiliary speed change double gear 11 is arranged at the group hole 1 46 in the gearbox cavity 45 composed of the box wall 3 40 and the box wall 41. One end of the auxiliary speed change double gear 11 is arranged in the gearbox cavity 3 44, and passes through the bearing, the shaft retaining ring, the middle gear meshing gear seat 13, the middle gear meshing sleeve 12, the middle gear driving gear 14, the retaining ring, the bearing, the upper end cover 15, the spacer, and the bearing from left to right in sequence. The upper end cover 15 is fixed to the box wall 41 by bolts for axial limitation of the right end of the auxiliary speed change double gear 11. The inner hole coaxial sleeve of the middle gear driving gear 14 is provided with a bushing, a needle bearing, and a needle bearing spacer, and the coaxial sleeve is on the auxiliary speed change double gear 11. The inner hole of the middle gear meshing gear seat 13 is spline meshed with the auxiliary speed change double gear 11.

[0051] One end of the crawler gear double gear 16 is coaxially installed with one end of the auxiliary speed change double gear 11 through a bearing, and the other end is coaxially installed with the rear axle box through a bearing. A small bevel gear shaft 22 is arranged inside the rear axle box through a bearing. The small bevel gear shaft 22 is coaxially arranged at the tail end of the output shaft 21. The small bevel gear shaft 22 coaxially passes through the crawler gear engagement seat 20 and the crawler gear driven gear 23 from left to right in sequence. The crawler gear engagement seat 20 is spline-engaged with one end of the small bevel gear shaft 22. The crawler gear engagement seat 20 is arranged on one side of the direct gear engagement seat 24 and is connected through the crawler gear engagement sleeve 19.

[0052] A shaft 7 is arranged at a group hole 1 46 in a gearbox cavity 3 44 formed by a wall wall 2 and a box wall 3 40. The shaft 7 passes through a bearing, a first gear driving gear 8, a shaft retaining ring, a shaft retaining ring, a second gear driving gear 9, a third gear driving gear 10, a synchronizer 6, a retaining ring, and a bearing coaxially from left to right. The right end of the shaft 7 is coaxially installed with the left end of the auxiliary speed change double gear 11 through a bearing. The first gear driving gear 8, the second gear driving gear 9, and the inner hole of the synchronizer 6 are spline-engaged with the shaft 7. The inner coaxial sleeve of the third gear driving gear 10 is provided with a bushing, a needle bearing, and a needle bearing retaining ring, which is sleeved on the shaft 7.

[0053] The input shaft 3 is arranged on the box wall 138 and passes through the group hole 146 in the gearbox cavity 142 and the gearbox cavity 243. The input shaft 3 coaxially passes through the oil seal, bearing, retaining ring, reverse gear driving gear 5, synchronizer 6, retaining ring, and bearing from left to right in sequence. The right end of the input shaft 3 is coaxially installed with the right end of the first shaft 7 through a bearing. The inner hole of the synchronizer 6 is splined with the input shaft 3. The inner hole of the reverse gear driving gear 5 is coaxially sleeved with a bushing, a needle bearing, and a needle bearing spacer, which is coaxially sleeved on the input shaft 3. The input bearing seat 4 is coaxially installed on the left end of the input shaft 3, and one end of the input bearing seat 4 is fixed to the box wall 138 by bolts for axial limit of the left end of the input shaft 3. The reverse gear driving gear 5 meshes with one end of the reverse gear double gear 35, and the reverse gear double gear 35 is coaxially sleeved on the reverse gear intermediate shaft 36 through a bearing. The reverse gear intermediate shaft 36 is arranged at the group hole 3 48 in the transmission cavity 2 43 composed of the box wall 1 38 and the box wall 2 39.

[0054] The power output front section shaft 2 coaxially passes through the inner hole of the input shaft 3, the inner hole of the first shaft 7, and the inner hole of the auxiliary speed double gear 11, and the power output rear section shaft 18 coaxially passes through the inner hole of the crawler gear double gear 16. The power output front section shaft 2 and the power output rear section shaft 18 are connected at the inner hole of the crawler gear double gear 16 through a connecting sleeve 17.

[0055] During use, the utility model:

[0056] When the forward gear is shifted down one gear, the power flows through the following route: Figure 5 As shown: engine - input shaft 3 - first shaft 7 - first gear driving gear 8 and first gear driven gear 34 of main transmission - second shaft 31 - auxiliary transmission double gear 11 and fourth gear driven gear 30 of main transmission - auxiliary transmission double gear 11 and low gear driven gear 27 - auxiliary transmission output shaft 21 - small bevel gear shaft 22.

[0057] When the reverse gear is engaged, the power flows through the following route: Figure 6 As shown: engine - input shaft 3 - reverse gear driving gear 5 and reverse gear double gear 35 - reverse gear double gear 35 and first gear driven gear 34 - secondary shaft 31 - main speed auxiliary gear double gear 11 and fourth gear driven gear 30 - auxiliary gear double gear 11 and low gear driven gear 27 - auxiliary gear output shaft 21 - small bevel gear shaft 22.

[0058] When the forward gear is engaged and the fourth gear is crawling, the power flows through the following route: Figure 7 As shown: engine - input shaft 3 - first shaft 7 - auxiliary transmission double gear 11 and fourth gear driven gear 30 - second shaft 31 - auxiliary transmission output shaft 21 - crawler gear double gear 16 and direct gear engagement seat 24 - crawler gear double gear 16 and crawler gear driven gear 23 - small bevel gear shaft 22.

[0059] When the reverse gear is engaged and the vehicle is crawling in the fourth gear, the power flows through the following route: Figure 8 As shown: engine - input shaft 3 - reverse gear driving gear 5 and reverse gear double gear 35 - reverse gear double gear 35 and first gear driven gear 34 - first gear driving gear 8 and first gear driven gear 34 of main transmission - first shaft 7 - auxiliary transmission double gear 11 and fourth gear driven gear 30 of main transmission - second shaft 31 - output shaft 21 of auxiliary transmission - crawler gear double gear 16 and direct gear engagement seat 24 - crawler gear double gear 16 and crawler gear driven gear 23 - small bevel gear shaft 22.

[0060] The above are only embodiments of the present application and are not intended to limit the present application. For those skilled in the art, the present application may have various changes and variations. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application should be included within the scope of the claims of the present application.

Claims

1. A tractor gearbox transmission structure, comprising a gearbox body (1), characterized in that: The gearbox body (1) is provided with a power output front shaft (2), an input shaft (3), an input bearing seat (4), a reverse gear driving gear (5), a synchronizer (6), a first shaft (7), a first gear driving gear (8), a second gear driving gear (9), a third gear driving gear (10), a secondary speed change double gear (11), a middle gear meshing sleeve (12), a middle gear meshing tooth seat (13), a middle gear driving gear (14), an upper end cover (15), a crawler gear double gear (16), a connecting sleeve (17), a power output rear shaft (18), a crawler gear meshing sleeve (19), a crawler gear meshing seat (20), an output shaft (21), a small bevel gear shaft (22), a crawler gear driven gear (23), a direct gear meshing seat (24), a lower end cover (25), a middle gear driven gear (26), a low gear driven gear (27), A high and low gear engagement seat (28), a high and low gear engagement sleeve (29), a fourth gear driven gear (30), a second shaft (31), a third gear driven gear (32), a second gear driven gear (33), a first gear driven gear (34), a reverse gear double gear (35), a reverse gear intermediate shaft (36) and a second shaft front end cover (37); the gearbox body (1) is also provided with four walls, namely a first box wall (38), a second box wall (39), a third box wall (40) and a fourth box wall (41); the gearbox body (1) is divided into four cavities, namely a first box cavity (42), a second box cavity (43), a third box cavity (44) and a fourth box cavity (45); and three groups of holes are provided in parallel on the vertical walls, namely a first group of holes (46), a second group of holes (47) and a third group of holes (48); The input shaft (3) is arranged on the first wall (38) of the housing and passes through the first group hole (46) in the first gearbox cavity (42) and the second gearbox cavity (43). The input shaft (3) passes through the reverse gear driving gear (5) and the synchronizer (6) coaxially from left to right in sequence. The right end of the input shaft (3) is coaxially mounted with the right end of the first shaft (7) through a bearing. The inner hole of the synchronizer (6) is spline-engaged with the input shaft (3). The inner hole of the reverse gear driving gear (5) is coaxially sleeved on the input shaft (3). The input bearing seat (4) is coaxially mounted on the left end of the input shaft (3), one end of the input bearing seat (4) is fixed to the first box wall (38) by bolts, and is used to limit the axial position of the left end of the input shaft (3), the reverse gear driving gear (5) is meshed with one end of the reverse gear double gear (35), the reverse gear double gear (35) is coaxially sleeved on the reverse gear intermediate shaft (36) through a bearing, and the reverse gear intermediate shaft (36) is arranged at the third group hole (48) in the second transmission cavity (43) formed by the first box wall (38) and the second box wall (39); The first shaft (7) is arranged at a group hole 1 (46) in a third gearbox cavity (44) formed by a second box wall (39) and a third box wall (40); the first shaft (7) coaxially passes through a first gear driving gear (8), a second gear driving gear (9), a third gear driving gear (10) and a synchronizer (6) from left to right in sequence; the right end of the first shaft (7) is coaxially mounted with the left end of the auxiliary speed change double gear (11) through a bearing; the inner holes of the first gear driving gear (8), the second gear driving gear (9) and the synchronizer (6) are spline-engaged with the first shaft (7); and the third gear driving gear (10) is loosely sleeved on the first shaft (7); One end of the crawler gear double gear (16) is coaxially mounted with one end of the auxiliary speed change double gear (11) via a bearing; The auxiliary speed change double gear (11) is arranged at a group hole one (46) in a gearbox cavity four (45) formed by a box wall three (40) and a box wall four (41); one end of the auxiliary speed change double gear (11) is arranged in the gearbox cavity three (44) and passes through the middle gear meshing tooth seat (13), the middle gear meshing sleeve (12), the middle gear driving gear (14) and the upper end cover (15) from left to right in sequence coaxially; the upper end cover (15) is fixed to the box wall four (41) by bolts and is used for axially limiting the right end of the auxiliary speed change double gear (11); the inner hole of the middle gear driving gear (14) is coaxially sleeved on the auxiliary speed change double gear (11); the inner hole of the middle gear meshing tooth seat (13) is spline meshed with the auxiliary speed change double gear (11); The output shaft (21) is arranged at a second group hole (47) in a gearbox cavity (45) formed by a third box wall (40) and a fourth box wall (41). The left end of the output shaft (21) is coaxially sleeved in the right end hole of the second shaft (31). The other end of the output shaft (21) is provided with a shaft retaining ring between the middle gear driven gear (26) and the bearing. The left end of the output shaft (21) is provided with a retaining ring which coaxially passes through the middle gear driven gear (26), the low gear driven gear (27), the high and low gear meshing seat (28) and the high and low gear meshing sleeve (29) in sequence from right to left. The right end of the shaft (21) mounting retaining ring coaxially passes through the lower end cover (25) and the direct gear engagement seat (24) from left to right in sequence. The lower end cover (25) is fixed to the box wall (41) by bolts and is used for axially limiting the rear end of the output shaft (21). The inner holes of the high and low gear engagement seat (28), the middle gear driven gear (26) and the direct gear engagement seat (24) are all spline-engaged with the output shaft (21). The inner hole of the high and low gear engagement sleeve (29) is spline-engaged with the high and low gear engagement seat (28). The inner hole of the low gear driven gear (27) is sleeved on the output shaft (21). The front end cover (37) of the second shaft is coaxially sleeved in the second group hole (47), one end of which is fixed to the first wall (38) of the box body by bolts, and the other end is in contact with the leftmost bearing end of the second shaft (31), and is used for axially limiting the front end of the second shaft (31); The second shaft (31) is arranged at a second group hole (47) in a third gearbox cavity (44) formed by a second box wall (39) and a third box wall (40). The second shaft (31) coaxially passes through a fourth gear driven gear (30), a third gear driven gear (32), a second gear driven gear (33), a synchronizer (6) and a first gear driven gear (34) from right to left, and is locked with a locking nut. The inner holes of the fourth gear driven gear (30), the third gear driven gear (32) and the synchronizer (6) are all spline-engaged with the second shaft (31). The second gear driven gear (33) and the first gear driven gear (34) are both loosely sleeved on the second shaft (31).

2. A tractor gearbox transmission structure according to claim 1, characterized in that: The inner holes of the second gear driven gear (33) and the first gear driven gear (34) are both coaxially sleeved with a bushing, a needle roller bearing and a needle roller bearing retaining ring.

3. A tractor gearbox transmission structure according to claim 1, characterized in that: Needle bearings are also arranged in the holes at the left end of the output shaft (21) and the right end of the second shaft (31), and are supported by the needle bearings.

4. A tractor gearbox transmission structure according to claim 1, characterized in that: The right end of the crawler gear double gear (16) is coaxially mounted with the rear axle case via a bearing, and the rear axle case is fixedly connected to the right side of the gearbox case (1).

5. A tractor gearbox transmission structure according to claim 4, characterized in that: A small bevel gear shaft (22) is arranged inside the rear axle housing via a bearing. The small bevel gear shaft (22) is coaxially arranged at the rear end of the output shaft (21). The small bevel gear shaft (22) coaxially passes through a crawler gear engagement seat (20) and a crawler gear driven gear (23) in sequence from left to right. The crawler gear engagement seat (20) is spline-engaged with one end of the small bevel gear shaft (22). The crawler gear engagement seat (20) is arranged on one side of a direct gear engagement seat (24) and is connected via a crawler gear engagement sleeve (19).

6. A tractor gearbox transmission structure according to claim 1, characterized in that: The power output front section shaft (2) coaxially passes through the inner hole of the input shaft (3), the inner hole of the first shaft (7), and the inner hole of the auxiliary speed change double gear (11); the power output rear section shaft (18) coaxially passes through the inner hole of the crawler gear double gear (16); the power output front section shaft (2) and the power output rear section shaft (18) are connected in the inner hole of the crawler gear double gear (16) through a connecting sleeve (17).

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