Gear box for rotary cultivator

Abstract

The utility model relates to the technical field of agricultural machinery, in particular to a gearbox for a rotary cultivator. Comprising a box body, a first box cover arranged on the first side face of the box body, an input shaft used for inputting power, an input bevel gear connected to the input shaft in the box body, a second box cover arranged on the second side face of the box body, and a long pipe connected to the second box cover. The output shaft is used for outputting power, the output bevel gear is connected to the output shaft in the box body and meshed with the input bevel gear, and the projection area of the output bevel gear on the second box cover is not larger than the area of the second box cover. The projection area of the input bevel gear on the first box cover is not larger than the projection area of the output bevel gear on the second box cover. The utility model provides a gear box for a rotary cultivator. Components in a box body are convenient to replace.

Description

Technical Field

[0001] The utility model relates to the technical field of agricultural machinery, in particular to a gear box for a rotary tiller. Background Art

[0002] Agricultural production rotary tillers are tilling machines that work with tractors to complete plowing and harrowing operations. They are widely used because of their strong soil crushing ability and flat surface after plowing. At the same time, they can cut up the root stubble buried below the surface, which is convenient for seed drill operations and provides a good seed bed for later sowing. The rotary tiller gearbox is the transmission system of the agricultural machinery for deep plowing operations in the farmland. The power is transmitted through the meshing of the input bevel gear and the output bevel gear inside the box. The existing gearbox usually has a box cover at the input bevel gear. This brings inconvenience to the replacement of the internal parts of the box when the area of ​​the input bevel gear or the output bevel gear is large.

[0003] For example, in the patent with Chinese patent authorization announcement number CN215950326U and the name of "crawler self-propelled rotary tiller gear box", it includes a box body, a third box cover is connected to one side wall of the box body, the third box cover is rotatably connected to the box body with an input shaft, one end of the input shaft close to the third box cover is exposed outside the third box cover for input, the input shaft is connected to an input spiral bevel gear inside the box body, a long tube is connected to the box body at a position of 90 degrees with the third box cover, the inside of the long tube is rotatably connected to an output shaft, the output shaft is connected to the inside of the box body with an output bevel gear, and the first box cover is connected to the long tube at one side close to the hexagon socket screw through a hexagonal bolt. The disadvantage is that when the output bevel gear needs to be replaced, the output shaft must be removed first, and when the area of ​​the input bevel gear or the output bevel gear is large, it is quite inconvenient to take out or put the parts from the box body. Utility Model Content

[0004] In view of the disadvantage that a box cover is provided at the input bevel gear of the existing rotary tiller gear box, when the area of ​​the input bevel gear or the output bevel gear is large, it is inconvenient to replace the internal parts of the box body from the box cover. The purpose of the utility model is to provide a gear box for a rotary tiller, which is convenient for replacing the internal parts of the box body.

[0005] To achieve the above purpose, the utility model provides the following technical solution: a gear box for a rotary tiller, comprising:

[0006] A box body, the box body being provided with a first side surface and a second side surface arranged adjacently;

[0007] A first box cover, arranged on a first side surface of the box body;

[0008] An input shaft is rotatably connected to the housing, one end of the input shaft passes through the first housing cover to the outside of the housing for inputting power; an input bevel gear is connected to the input shaft inside the housing;

[0009] A second box cover is arranged on a second side surface of the box body;

[0010] A long tube connected to the second tank cover, wherein the long tube is perpendicular to the input shaft;

[0011] An output shaft is rotatably connected to the inside of the long tube, and one end of the output shaft away from the output bevel gear passes through the long tube to the outside of the box to output power;

[0012] The output bevel gear is connected to the output shaft inside the casing and meshes with the input bevel gear. The projected area of ​​the output bevel gear on the second casing cover is not larger than the area of ​​the second casing cover, and the projected area of ​​the input bevel gear on the first casing cover is not larger than the projected area of ​​the output bevel gear on the second casing cover.

[0013] In the technical solution, the gearbox for a rotary tiller includes a box body having adjacent first and second sides, and a first box cover and a second box cover respectively arranged on the two sides, and the input shaft and the output shaft pass through the first box cover and the second box cover respectively to the outside of the box body, so that the maintenance of the input shaft and the output shaft is more convenient, and there is no need to disassemble the entire box body. Since the projection area of ​​the output bevel gear on the second box cover is not larger than the area of ​​the second box cover, and the projection area of ​​the input bevel gear on the first box cover is not larger than the projection area of ​​the output bevel gear on the second box cover, the second box cover can provide sufficient opening space, so that the output bevel gear and the input bevel gear can be replaced through the second box cover. When the bevel gear needs to be replaced, the maintenance personnel have enough space to operate without large-scale disassembly of the box body. Through the unique structural layout, the maintainability and replacement convenience of the internal parts of the box body are significantly improved.

[0014] The utility model is further configured as follows: a clamping groove is provided at one end of the output shaft close to the output bevel gear, and a retaining spring for limiting the output bevel gear is provided in the clamping groove. Through this configuration, on the one hand, the combination of the clamping groove and the retaining spring provides a stable limiting mechanism for the output bevel gear, and during the operation of the gearbox, the output bevel gear can be accurately fixed on the output shaft to prevent it from being displaced or falling off due to vibration or impact, thereby ensuring the stability and reliability of the transmission. On the other hand, by adjusting the position of the retaining spring, maintenance personnel can easily fix the output bevel gear at a predetermined position, or remove it from the output shaft, thereby improving the maintenance efficiency and convenience of the gearbox.

[0015] The utility model is further configured as follows: the long tube and the second box cover are an integrally formed structure. Through this configuration, firstly, the integrally formed structure significantly improves the structural strength and overall rigidity between the long tube and the second box cover. Compared with traditional connection methods, such as welding or bolting, integral forming can avoid stress concentration and fatigue fracture that may occur at the connection, thereby enhancing the safety and durability of the gearbox. Secondly, the integral forming design also optimizes the production process, reduces the assembly links in the manufacturing process, and improves production efficiency. At the same time, since there are no additional connectors, the material cost and weight are also reduced, making the gearbox lighter and more economical. Furthermore, from the perspective of appearance and aesthetics, the integrally formed structure makes the transition between the long tube and the second box cover more natural and smooth, which improves the overall texture and visual effect of the product.

[0016] The utility model is further configured as follows: a third box cover is further provided on the box body, the third box cover is provided on the opposite side of the first box cover, and an oil mirror is provided on the third box cover. Through this configuration, maintenance personnel can easily access the interior of the gear box by opening the third box cover to perform necessary inspection and maintenance work, which not only improves maintenance efficiency but also reduces maintenance costs. Through the oil mirror, the operator can intuitively observe the oil level inside the gear box, thereby ensuring that the lubricating oil is always maintained at an appropriate level, which can not only avoid mechanical wear caused by too low an oil level, but also promptly discover and solve potential lubrication problems, greatly extending the service life of the gear box.

[0017] The utility model is further configured as follows: the first box cover, the second box cover and the third box cover are all connected to the box body by bolts. The bolt connection ensures the firmness and stability between the box cover and the box body, can withstand large tensile and shear forces, and effectively prevents the box cover from accidentally falling off or shifting during the operation of the gear box, thereby ensuring the normal operation of the equipment. The bolt connection also has good detachability, which is convenient for repairing and replacing the box cover. When the gear box needs to be inspected or parts need to be replaced, the maintenance personnel can easily remove the bolts, remove the box cover, and reinstall it after completing the maintenance work, which greatly improves the convenience and efficiency of maintenance.

[0018] The utility model is further configured as follows: the first case cover is provided with an assembly opening for matching the input shaft, and a first tapered roller bearing is connected between the input shaft and the assembly opening. The arrangement of the assembly opening ensures that the input shaft can be accurately mounted on the first case cover, providing a stable interface for power input. This not only simplifies the installation process, but also improves the accuracy and efficiency of assembly. The first tapered roller bearing is suitable for bearing a large combined radial and axial load, so that the input shaft can remain stable when rotating at high speed, reduce vibration and noise, and thus improve the overall performance of the gearbox.

[0019] The utility model is further configured as follows: the output shaft is connected to the long tube through a second tapered roller bearing, the side wall of the second tapered roller bearing close to the output bevel gear contacts the wall of the output bevel gear, and the other side wall of the second tapered roller bearing away from the output bevel gear contacts the wall of the long tube. The second tapered roller bearing can fit tightly between the output bevel gear and the long tube, ensuring the smooth transmission of power. The side wall of the second tapered roller bearing close to the output bevel gear is in close contact with the wall of the bevel gear, while the other side wall away from the bevel gear is connected to the wall of the long tube, which not only effectively disperses the load during the transmission process, but also enhances the stability of the structure. The use of the second tapered roller bearing also significantly reduces friction and wear, thereby extending the service life of the gearbox. At the same time, the transmission efficiency is also improved, so that the rotary tiller can be smoother and more efficient when working.

[0020] The utility model is further configured as follows: a flange is sleeved on the outer end of the output shaft away from the second box cover, a third tapered roller bearing is connected between the output shaft and the flange, a side wall of the third tapered roller bearing close to the output bevel gear contacts the wall of the long tube, and the other side wall of the third tapered roller bearing away from the output bevel gear contacts the wall of the flange. By introducing the third tapered roller bearing between the output shaft and the flange, the stability and reliability of the transmission are greatly improved, and the third tapered roller bearing can withstand large radial and axial loads, thereby ensuring that the output shaft can smoothly and accurately transmit power during the operation of the rotary tiller. The side wall of the third tapered roller bearing close to the output bevel gear is in close contact with the wall of the long tube, while the other side wall away from the output bevel gear is connected to the wall of the flange, ensuring that the bearing can be effectively supported during the operation, further enhancing the stability and durability of the transmission. The flange not only increases the structural strength of the output end, but also facilitates the connection and disassembly with other equipment, thereby improving the overall convenience of the rotary tiller.

[0021] The utility model is further configured as follows: a breathable plug for adjusting the air pressure balance inside the gearbox is provided on the housing. During the operation of the gearbox, due to the increase in temperature and the agitation of the lubricating oil, pressure changes may occur inside the housing. The breathable plug can discharge or inhale air in time to keep the air pressure inside the housing stable, thereby preventing mechanical failures caused by air pressure imbalance. The breathable plug also protects the gearbox from the invasion of external pollutants. By providing a special breathable channel, the breathable plug can prevent dust, moisture and other impurities from entering the housing, ensuring that key components such as gears and bearings operate in a clean environment, thereby extending the service life of the gearbox.

[0022] The utility model is further configured as follows: an inner skeleton double lip oil seal is provided between the first case cover and the input shaft and between the output shaft and the flange. The inner skeleton double lip oil seal can effectively prevent the lubricating oil from leaking from the inside of the case, ensure the normal operation of the lubrication system inside the gearbox, thereby maintaining the stability and durability of the gearbox, and also helps to prevent external impurities, such as dust, moisture and pollutants, from invading the inside of the gearbox.

[0023] The advantages of the utility model are: (1) the maintainability and replacement convenience of the internal parts of the box body are significantly improved; (2) the projected area of ​​the output bevel gear on the second box cover is not larger than the area of ​​the second box cover, and the projected area of ​​the input bevel gear on the first box cover is not larger than the projected area of ​​the output bevel gear on the second box cover. The second box cover can provide sufficient opening space so that both the output bevel gear and the input bevel gear can be replaced through the second box cover. When the bevel gear needs to be replaced, the maintenance personnel have enough space to operate without large-scale disassembly of the box body; (3) The integrally formed structure of the long tube and the second box cover improves the structural strength and overall rigidity between the long tube and the second box cover. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 It is a schematic diagram of the structure of the utility model;

[0025] Figure 2 A bottom view of a gear box in one embodiment of the utility model;

[0026] Figure 3 A cross-sectional view of a gear box in one embodiment of the utility model;

[0027] Figure 4 for Figure 3 Enlarged view of point A in the middle.

[0028] In the figure: 1. box body; 11. first box cover; 12. second box cover; 13. third box cover; 131. oil mirror; 14. breather plug; 2. input shaft; 3. long tube; 4. input bevel gear; 5. output bevel gear; 6. output shaft; 61. slot; 62. retaining spring; 71. first tapered roller bearing; 72. second tapered roller bearing; 73. third tapered roller bearing; 8. flange; 9. inner skeleton double lip oil seal. DETAILED DESCRIPTION

[0029] In the description of this embodiment, it should be noted that if the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", "front", "back", etc. appear, the orientation or position relationship indicated is based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operate in a specific orientation, and therefore, cannot be understood as a limitation on the utility model. In addition, if the terms "first", "second", and "third" appear, they are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0030] The utility model is further described below in conjunction with the accompanying drawings of the specification.

[0031] Embodiment 1:

[0032] Reference Figures 1 to 4 , a gear box for a rotary tiller, comprising:

[0033] A box body 1, wherein the box body 1 is provided with a first side surface and a second side surface arranged adjacently;

[0034] A first box cover 11, arranged on a first side surface of the box body 1;

[0035] An input shaft 2 is rotatably connected to the housing 1, and one end of the input shaft 2 passes through the first housing cover 11 to the outside of the housing 1 for inputting power;

[0036] An input bevel gear 4 is connected to the input shaft 2 inside the housing 1;

[0037] A second box cover 12, arranged on a second side surface of the box body 1;

[0038] A long tube 3 is connected to the second tank cover 12, and the long tube 3 is perpendicular to the input shaft 2;

[0039] An output shaft 6 is rotatably connected to the inside of the long tube 3, and one end of the output shaft 6 away from the output bevel gear 5 passes through the long tube 3 to the outside of the box body 1 for outputting power;

[0040] The output bevel gear 5 is connected to the output shaft 6 inside the casing 1 and meshes with the input bevel gear 4. The projection area of ​​the output bevel gear 5 on the second casing cover 12 is not larger than the area of ​​the second casing cover 12. The projection area of ​​the input bevel gear 4 on the first casing cover 11 is not larger than the projection area of ​​the output bevel gear 5 on the second casing cover 12.

[0041] In this embodiment, the gearbox for a rotary tiller includes a housing 1 having adjacent first and second sides, and a first housing cover 11 and a second housing cover 12 respectively arranged on the two sides. The input shaft 2 and the output shaft 6 pass through the first housing cover 11 and the second housing cover 12 to the outside of the housing 1, respectively, so that the maintenance of the input shaft 2 and the output shaft 6 is more convenient without disassembling the entire housing 1. Since the projection area of ​​the output bevel gear 5 on the second housing cover 12 is not larger than the area of ​​the second housing cover 12, and the projection area of ​​the input bevel gear 4 on the first housing cover 11 is not larger than the projection area of ​​the output bevel gear 5 on the second housing cover 12, the second housing cover 12 can provide sufficient opening space, so that the output bevel gear 5 and the input bevel gear 4 can be replaced through the second housing cover 12. When the bevel gear needs to be replaced, the maintenance personnel have enough space to operate without large-scale disassembly of the housing 1. Through the unique structural layout, the maintainability and replacement convenience of the internal parts of the housing 1 are significantly improved.

[0042] It can be understood that the internal parts refer to the output bevel gear 5 , the input bevel gear 4 , the retaining ring 62 , the first tapered roller bearing 71 , and the second tapered roller bearing 72 .

[0043] refer to Figure 4 , a slot 61 is provided at one end of the output shaft 6 close to the output bevel gear 5, and a retaining spring 62 is provided in the slot 61 for limiting the output bevel gear 5. On the one hand, the combination of the slot 61 and the retaining spring 62 provides a stable limiting mechanism for the output bevel gear 5. During the operation of the gearbox, the output bevel gear 5 can be accurately fixed on the output shaft 6 to prevent it from being displaced or falling off due to vibration or impact, thereby ensuring the stability and reliability of the transmission. On the other hand, by adjusting the position of the retaining spring 62, maintenance personnel can easily fix the output bevel gear 5 at a predetermined position, or remove it from the output shaft 6, thereby improving the maintenance efficiency and convenience of the gearbox.

[0044] refer to Figures 1 to 3 , the long tube 3 and the second box cover 12 are an integrally molded structure. First, the integrally molded structure significantly improves the structural strength and overall rigidity between the long tube 3 and the second box cover 12. Compared with traditional connection methods, such as welding or bolting, one-piece molding can avoid stress concentration and fatigue fracture that may occur at the connection, thereby enhancing the safety and durability of the gearbox. Secondly, the one-piece molding design also optimizes the production process, reduces the assembly links in the manufacturing process, and improves production efficiency. At the same time, since there are no additional connectors, it also reduces material costs and weight, making the gearbox lighter and more economical. Furthermore, from the perspective of appearance and aesthetics, the one-piece molding structure makes the transition between the long tube 3 and the second box cover 12 more natural and smooth, which improves the overall texture and visual effect of the product.

[0045] refer to Figures 1 to 3The housing 1 is also provided with a third box cover 13, which is arranged on the opposite side of the first box cover 11, and an oil mirror 131 is provided on the third box cover 13. Maintenance personnel can easily access the interior of the gearbox by opening the third box cover 13 to perform necessary inspection and maintenance work, which not only improves maintenance efficiency but also reduces maintenance costs. Through the oil mirror 131, the operator can intuitively observe the oil level inside the gearbox, thereby ensuring that the lubricating oil is always maintained at an appropriate level, which can not only avoid mechanical wear caused by too low an oil level, but also promptly discover and solve potential lubrication problems, greatly extending the service life of the gearbox.

[0046] In one embodiment of the present invention, reference Figures 1 to 3 , the first box cover 11, the second box cover 12 and the third box cover 13 are all connected to the box body 1 by bolts. The bolt connection ensures the firmness and stability between the box cover and the box body 1, can withstand large tensile and shear forces, and effectively prevents the box cover from accidentally falling off or shifting during the operation of the gearbox, thereby ensuring the normal operation of the equipment. The bolt connection also has good detachability, which is convenient for repairing and replacing the box cover. When the gearbox needs to be inspected or parts need to be replaced, the maintenance personnel can easily remove the bolts, remove the box cover, and reinstall it after completing the maintenance work, which greatly improves the convenience and efficiency of maintenance.

[0047] Preferably, reference Figure 4 , the first case cover 11 is provided with an assembly port for matching the input shaft 2, and a first tapered roller bearing 71 is connected between the input shaft 2 and the assembly port. The setting of the assembly port ensures that the input shaft 2 can be accurately installed on the first case cover 11, providing a stable interface for power input. It not only simplifies the installation process, but also improves the accuracy and efficiency of assembly. The first tapered roller bearing 71 is suitable for bearing large radial and axial combined loads, so it can ensure that the input shaft 2 remains stable when rotating at high speed, reduce vibration and noise, and thus improve the overall performance of the gearbox.

[0048] In one embodiment of the present invention, reference Figure 4The output shaft 6 is connected to the long tube 3 through a second tapered roller bearing 72. The side wall of the second tapered roller bearing 72 close to the output bevel gear 5 contacts the wall of the output bevel gear 5, and the other side wall of the second tapered roller bearing 72 away from the output bevel gear 5 contacts the wall of the long tube 3. The second tapered roller bearing 72 can fit tightly between the output bevel gear 5 and the long tube 3, ensuring the smooth transmission of power. The side wall of the second tapered roller bearing 72 close to the output bevel gear 5 contacts the wall of the bevel gear, while the other side wall away from the bevel gear contacts the wall of the long tube 3, which not only effectively disperses the load during the transmission process, but also enhances the stability of the structure. The use of the second tapered roller bearing 72 also significantly reduces friction and wear, thereby extending the service life of the gearbox. At the same time, the transmission efficiency is also improved, so that the rotary tiller can be smoother and more efficient when working.

[0049] In one embodiment of the present invention, reference Figure 4 The output shaft 6 is provided with a flange 8 on the outer side of one end away from the second housing cover 12, and a third tapered roller bearing 73 is connected between the output shaft 6 and the flange 8. The wall surface of the third tapered roller bearing 73 on one side close to the output bevel gear 5 contacts the wall surface of the long tube 3, and the wall surface of the third tapered roller bearing 73 on the other side away from the output bevel gear 5 contacts the wall surface of the flange 8. By introducing the third tapered roller bearing 73 between the output shaft 6 and the flange 8, the stability and reliability of the transmission are greatly improved. The third tapered roller bearing 73 can withstand large radial and axial loads, thereby ensuring that the output shaft 6 can smoothly and accurately transmit power during the operation of the rotary tiller. The wall surface of the third tapered roller bearing 73 on one side close to the output bevel gear 5 is in close contact with the wall surface of the long tube 3, while the wall surface of the other side away from the output bevel gear 5 is connected to the wall surface of the flange 8, ensuring that the bearing can be effectively supported during the operation, further enhancing the stability and durability of the transmission. The flange 8 not only increases the structural strength of the output end, but also facilitates the connection and disassembly with other equipment, thereby improving the overall convenience of use of the rotary tiller.

[0050] refer to Figure 4 An inner skeleton double lip oil seal 9 is provided between the first housing cover 11 and the input shaft 2 and between the output shaft 6 and the flange 8. The inner skeleton double lip oil seal 9 can effectively prevent the lubricating oil from leaking from the inside of the housing 1, ensure the normal operation of the lubrication system inside the gearbox, thereby maintaining the stability and durability of the gearbox, and also help prevent external impurities such as dust, moisture and pollutants from invading the inside of the gearbox.

[0051] Preferably, the housing 1 is provided with a breathable plug 14 for adjusting the air pressure balance inside the gearbox. During the operation of the gearbox, due to the increase in temperature and the agitation of the lubricating oil, pressure changes may occur inside the housing 1. The breathable plug 14 can discharge or inhale air in time to keep the air pressure inside the housing 1 stable, thereby preventing mechanical failures caused by air pressure imbalance. The breathable plug 14 also protects the gearbox from the invasion of external pollutants. By setting a special breathable channel, the breathable plug 14 can prevent dust, moisture and other impurities from entering the housing 1, ensuring that key components such as gears and bearings operate in a clean environment, thereby extending the service life of the gearbox.

[0052] The specific description of the present invention in the above embodiments is only used to further illustrate the present invention and cannot be understood as limiting the scope of protection of the present invention. Technical engineers in this field may make some non-essential improvements and adjustments to the present invention based on the contents of the above-mentioned utility model, which fall within the scope of protection of the present invention.

Claims

1. A gearbox for a rotary tiller, characterized in that: include: A box body, the box body being provided with a first side surface and a second side surface arranged adjacently; A first box cover, arranged on a first side surface of the box body; An input shaft is rotatably connected to the housing, one end of the input shaft passes through the first housing cover to the outside of the housing for inputting power; an input bevel gear is connected to the input shaft inside the housing; A second box cover is arranged on a second side surface of the box body; A long tube connected to the second tank cover, wherein the long tube is perpendicular to the input shaft; An output shaft is rotatably connected to the inside of the long tube, and one end of the output shaft away from the output bevel gear passes through the long tube to the outside of the box to output power; The output bevel gear is connected to the output shaft inside the casing and meshes with the input bevel gear. The projected area of ​​the output bevel gear on the second casing cover is not larger than the area of ​​the second casing cover, and the projected area of ​​the input bevel gear on the first casing cover is not larger than the projected area of ​​the output bevel gear on the second casing cover.

2. A gearbox for a rotary tiller according to claim 1, characterized in that: A clamping groove is arranged at one end of the output shaft close to the output bevel gear, and a clamping spring for limiting the output bevel gear is arranged in the clamping groove.

3. A gearbox for a rotary tiller according to claim 2, characterized in that: The long tube and the second box cover are an integrally formed structure.

4. A gearbox for a rotary tiller according to claim 3, characterized in that: The box body is also provided with a third box cover, which is arranged on the opposite side of the first box cover and is provided with an oil mirror.

5. A gearbox for a rotary tiller according to claim 4, characterized in that: The first box cover, the second box cover and the third box cover are all connected to the box body by bolts.

6. A gearbox for a rotary tiller according to claim 4 or 5, characterized in that: The first box cover is provided with an assembly opening for matching the input shaft, and a first tapered roller bearing is connected between the input shaft and the assembly opening.

7. The gear box for a rotary tiller according to claim 6, characterized in that: The output shaft is connected to the long tube via a second tapered roller bearing, a side wall of the second tapered roller bearing close to the output bevel gear contacts the wall of the output bevel gear, and the other side wall of the second tapered roller bearing away from the output bevel gear contacts the wall of the long tube.

8. The gear box for a rotary tiller according to claim 7, characterized in that: A flange is provided on the outer side of one end of the output shaft away from the second box cover, and a third tapered roller bearing is connected between the output shaft and the flange. The wall surface of one side of the third tapered roller bearing close to the output bevel gear contacts the wall surface of the long tube, and the wall surface of the other side of the third tapered roller bearing away from the output bevel gear contacts the wall surface of the flange.

9. The gear box for a rotary tiller according to claim 1, characterized in that: The box body is provided with a vent plug for adjusting the air pressure balance inside the gear box.

10. The gear box for a rotary tiller according to claim 8, characterized in that: An inner skeleton double-lip oil seal is provided between the first box cover and the input shaft and between the output shaft and the flange.

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