Tractor rear PTO transmission case and tractor

Abstract

The utility model relates to the field of tractor PTO, concretely relates to a tractor rear PTO transmission case and tractor, include: transmission case casing, driving double gear shaft, install in transmission case casing through first bearing, passive axle, install in transmission case casing through two second bearings, high grade passive gear and low grade passive gear, set up on passive axle, high grade passive gear and low grade passive gear install through third bearing and passive axle cooperation respectively, meshing sleeve, shift fork subassembly, shift fork subassembly and meshing sleeve linkage connection, power output shaft, connect through output shaft bung and passive axle, and realize sealing through oil seal, brake device, brake device set up between driving double gear shaft and transmission case casing, casing cover plate, can be detachably set up in the installation mouth of transmission case casing, gear shaft end cover, can be detachably connected with casing cover plate, be used for sealing one end of driving double gear shaft. The whole scheme can realize convenient dismounting maintenance.

Description

Technical Field

[0001] This utility model relates to the field of PTO (Power Transfer Toggle) for tractors, and more specifically, to a rear-mounted PTO gearbox for a tractor and the tractor itself. Background Technology

[0002] The power take-off (PTO) unit of a tractor, as a key component connecting the tractor to various agricultural implements, directly affects the efficiency of agricultural operations. In the process of modern agricultural mechanization, tractors not only need to provide power for their own movement but also need to transmit engine power to implements such as rotary tillers, seeders, and harvesters through the PTO. Traditional PTO structures mostly adopt an integrated design, with its gear transmission system, clutch mechanism, and rear axle transmission system integrated into the rear axle housing, outputting power through the main shaft.

[0003] In existing technologies, PTO structures typically include core components such as input gear sets, transmission gear sets, output shafts, and clutch devices. These components all require precision machining and assembly to transmit power. To achieve different speed outputs, some models employ multi-stage gear transmission structures, changing the speed ratio by switching gear meshing states using shift forks. While this integrated design ensures structural compactness, it reveals significant drawbacks in practical applications: when the PTO component malfunctions, maintenance personnel must completely disassemble the rear axle housing to access internal components, which is not only time-consuming and labor-intensive but may also affect the sealing performance of other transmission components; if users need to add or change output speed specifications, the entire gear transmission system must be replaced, or even the rear axle housing structure redesigned, resulting in high modification costs. Utility Model Content

[0004] The purpose of this utility model is to provide a rear-mounted PTO transmission box for tractors, which is easy to disassemble and maintain.

[0005] Another objective of this invention is to provide a tractor that is easy to disassemble and maintain.

[0006] The technical solution of this utility model is implemented as follows: A tractor rear-mounted PTO transmission box, comprising: Transmission housing; The active double gear shaft is rotatably mounted inside the transmission housing via a first bearing; The passive shaft is rotatably mounted inside the transmission housing via two second bearings; A high-grade driven gear and a low-grade driven gear are mounted on the driven shaft, and the high-grade driven gear and the low-grade driven gear are respectively installed with the driven shaft through a third bearing; The engagement sleeve is used to selectively engage with the high-gear driven gear or the low-gear driven gear to achieve power output at different gears; A shift fork assembly, which is linked to the engagement sleeve, is used to control the engagement sleeve to switch between high and low gears; The power take-off shaft is connected to the driven shaft via an output shaft plug and is sealed by an oil seal. A braking device is disposed between the drive double gear shaft and the transmission housing, and is used to realize the power cut-off and braking of the PTO transmission housing; A housing cover is detachably mounted on the mounting port of the transmission housing; A gear shaft end cap, detachably connected to the housing cover plate, is used to seal one end of the active double gear shaft.

[0007] Furthermore, the braking device includes a piston seat, a piston, a disc spring, a friction plate, a partition, a baffle, and a retaining ring. The piston seat is connected to the transmission housing by a first screw. The piston is mounted on the piston seat, and a disc spring for generating axial restoring force is provided between the piston and the piston seat. The piston is sealed to the piston seat and the transmission housing by a first O-ring and a second O-ring, respectively. The friction plate and the partition are respectively assembled between the active double gear shaft and the transmission housing. The baffle is assembled on the transmission housing through the snap ring. The braking device moves to the left through the piston. The friction force formed by the friction plate, the partition and the baffle realizes the braking of the active double gear shaft.

[0008] Furthermore, a spacer is provided on the driven shaft, and the high-grade driven gear and the low-grade driven gear are axially positioned and locked by the spacer and the locking nut.

[0009] Furthermore, the shift fork assembly includes a shift fork shaft, a shift fork, and a shift fork head. The shift fork shaft is fixed to the transmission housing by a second screw, and the shift fork drives the engagement sleeve to move through the shift fork head to achieve high and low gear switching.

[0010] Furthermore, the transmission housing adopts a modular design and can be detachably installed on the outside of the tractor's rear axle.

[0011] Furthermore, the housing cover is connected and fixed to the transmission housing by a locating pin and a third screw.

[0012] Furthermore, the gear shaft end cap is connected to the housing cover plate by a fourth screw.

[0013] Furthermore, both the first bearing and the second bearing are roller bearings.

[0014] Furthermore, the third bearing is a needle roller bearing.

[0015] A tractor, including the rear-mounted PTO transmission box of the tractor.

[0016] Compared with the prior art, the beneficial effects of this utility model are: The PTO transmission case provided in this application is a separate housing structure, mounted outside the tractor's rear axle, and internally contains a complete set of gears, brakes, and shifting mechanisms. Its core structure includes: 1. Main drive shaft (active double gear shaft): This is the power input shaft, which connects to the tractor gearbox.

[0017] 2. Driven shaft and two gears (high-speed driven gear and low-speed driven gear): These two gears can mesh with the main drive shaft respectively to achieve different output speeds.

[0018] 3. Gear shifting structure (shift fork assembly + engagement sleeve): By operating the shift fork, the engagement sleeve is pushed to select the higher or lower gear.

[0019] 4. Braking device: used to cut off power and brake the PTO transmission box.

[0020] 5. Sealing and support structure (multiple bearings, oil seals, gear shaft end caps, etc.): Ensures good sealing inside the transmission box, smooth operation, and no oil leakage.

[0021] These structural designs offer the following advantages: 1. Easy to disassemble and maintain: As it is an independent structure, it can be disassembled as a whole during maintenance without removing the rear axle.

[0022] 2. Compact structure and highly modular: suitable for matching different tractor models, facilitating serialization development.

[0023] 3. Smoother gear shifting: Equipped with a braking device, the drive shaft can stop quickly during gear shifting, preventing gear grinding.

[0024] 4. High scalability: If more speed options are needed, simply replace the gears or add components, resulting in low development costs. Attached Figure Description

[0025] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0026] Figure 1 This is a cross-sectional view of the rear-mounted PTO transmission box of the tractor according to this utility model; Figure 2 This utility model Figure 1 Sectional view at point BB.

[0027] In the picture: 1-Transmission box housing; 2-Positioning pin; 3-Housing cover plate; 4-Gear shaft end cover; 5-First bearing; 6-Driving double gear shaft; 7-Fourth screw; 8-Locking nut; 9-Driven shaft; 10-Spacer; 11-Third bearing; 12-Low-gear driven gear; 13-Third screw; 14-High-gear driven gear; 15-Second bearing; 16-Oil seal; 17-Output shaft plug; 18-Power output shaft; 19-Fifth screw; 20-First screw; 21-Piston seat; 22-First O-ring; 23-Piston; 24-Disc spring; 25-Second O-ring; 26-Friction plate; 27-Baffle plate; 28-Baffle plate; 29-Snap ring; 30-Second screw; 31-Shift fork shaft; 32-Shift fork; 33-Shift fork head; 34-Meshing sleeve. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0029] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.

[0030] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.

[0031] In the description of this utility model, it should be noted that the terms "center," "upper," "lower," "left," "right," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product of this utility model is in use. They are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this utility model. In addition, the terms "first," "second," and "third," etc., are only used to distinguish descriptions and should not be construed as indicating or implying relative importance.

[0032] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.

[0033] In the description of this utility model, it should also be noted that, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.

[0034] The following detailed description, in conjunction with the accompanying drawings, outlines some embodiments of the present invention. Unless otherwise specified, the following embodiments and features can be combined with each other.

[0035] Example 1 Currently, most tractors on the market have their PTO (Power Transfer Towing) structure integrated inside the rear axle housing (though some have a front-mounted PTO), which presents the following problems: 1. Inconvenient to repair and replace: Due to its complex structure, disassembly and assembly are troublesome.

[0036] 2. Poor adaptability: If users need power output at different speeds, it is costly and difficult to modify.

[0037] 3. Not conducive to modular design: Different models require redesigning the entire structure, resulting in low development efficiency.

[0038] Therefore, the starting point of this technology is to solve these problems by providing a PTO structure that is easy to disassemble, adjust, and expand. This solution is a rear-mounted PTO transmission box designed for tractors. Its function is to transmit the power of the tractor engine to the agricultural implements (such as rotary tillers and lawnmowers) at the rear via gears and shafts, enabling these devices to operate normally and facilitating disassembly and maintenance. The specific solution is as follows: Reference Figures 1-2 A tractor rear-mounted PTO transmission box, comprising: Transmission housing 1; The active double gear shaft 6 is rotatably mounted inside the transmission housing 1 via the first bearing 5; The passive shaft 9 is rotatably mounted inside the transmission housing 1 via the second bearing 15; High-grade driven gear 14 and low-grade driven gear 12 are mounted on driven shaft 9. High-grade driven gear 14 and low-grade driven gear 12 are respectively installed with driven shaft 9 through third bearing 11. The engagement sleeve 34 is used to selectively engage with the high-gear driven gear 14 or the low-gear driven gear 12 to achieve power output at different gears. The shift fork assembly is linked to the engagement sleeve 34 and is used to control the engagement sleeve 34 to switch between high and low gears. The power output shaft 18 is connected to the driven shaft 9 through the output shaft plug 17 and is sealed by the oil seal 16; The braking device is located between the drive double gear shaft 6 and the transmission housing 1, and is used to realize the power cut-off and braking of the PTO transmission housing. The housing cover 3 is detachably mounted on the mounting port of the transmission housing 1; The gear shaft end cover 4 is detachably connected to the housing cover plate 3 and is used to seal one end of the drive double gear shaft 6.

[0039] Specifically, the braking device includes a piston seat 21, a piston 23, a disc spring 24, a friction plate 26, a partition 27, a baffle 28, and a retaining ring 29. The piston seat 21 is connected to the transmission housing 1 by a first screw 20. The piston 23 is mounted on the piston seat 21, and a disc spring 24 for generating axial restoring force is provided between the piston 23 and the piston seat 21. The piston 23 is sealed to the piston seat 21 and the transmission housing 1 by a first O-ring 22 and a second O-ring 25, respectively.

[0040] Friction plate 26 and partition plate 27 are respectively assembled between the drive double gear shaft 6 and the transmission housing 1. Baffle plate 28 is assembled on the transmission housing 1 through snap ring 29. The braking device moves to the left through piston 23. The friction force formed by friction plate 26, partition plate 27 and baffle plate 28 realizes the braking of drive double gear shaft 6.

[0041] A spacer 10 is also provided on the passive shaft 9 and on the side near the mounting port of the transmission housing 1. The high-grade passive gear 14 and the low-grade passive gear 12 are axially positioned and locked by the spacer 10 and the locking nut 8.

[0042] The shift fork assembly includes a shift fork shaft 31, a shift fork 32, and a shift fork head 33. The shift fork shaft 31 is fixed to the transmission housing 1 by a second screw 30. The shift fork 32 drives the engagement sleeve 34 to move through the shift fork head 33, thereby realizing the switching between high and low gears.

[0043] The transmission housing 1 adopts a modular design and can be detachably installed on the outside of the tractor's rear axle for easy disassembly and maintenance.

[0044] The housing cover 3 is connected and fixed to the transmission box housing 1 by the positioning pin 2 and the third screw 13.

[0045] The gear shaft end cover 4 is connected to the housing cover plate 3 by the fourth screw 7.

[0046] Both the first bearing 5 and the second bearing 15 are roller bearings.

[0047] The third bearing 11 is a needle roller bearing.

[0048] The housing cover 3 is connected to the transmission housing 1 via the positioning pin 2 and the third screw 13. The drive double gear shaft 6 is assembled inside the transmission housing 1 via two roller bearings (first bearing 5). The gear shaft end cover 4 is connected to the housing cover 3 via the fourth screw 7. The piston seat 21 is connected to the transmission housing 1 via the first screw 20. The piston 23 is assembled on the piston seat 21, and the piston 23 is sealed to the piston seat 21 and the transmission housing 1 via the first O-ring 22 and the second O-ring 25 respectively, forming a sealed cavity. The return force is generated by the disc spring 24. The friction plate 26 and the partition plate 27 are assembled between the drive double gear shaft 6 and the transmission housing 1. The baffle plate 28 is assembled on the transmission housing 1 via the snap ring 29. When the piston 23 moves to the left, the friction force generated by the friction plate 26, the partition plate 27 and the baffle plate 28... To achieve braking of the active double gear shaft 6, the passive shaft 9 is assembled inside the housing via two roller bearings (second bearing 15). The low-gear passive gear 12 and the high-gear passive gear 14 are respectively assembled on the passive shaft 9 via needle roller bearings (third bearing 11) and locked by spacer 10 and lock nut 8. At the other end, the power output shaft 18 is connected to the passive shaft 9 via output shaft plug 17 and fifth screw 19 and sealed by oil seal 16. The shift fork shaft 31 is assembled on the transmission housing 1. The shift fork 32 is connected to the shift fork shaft 31 via set screw (second screw 30). The shift fork head 33 is assembled on the shift fork 32. By rotating the shift fork shaft 31, the shift fork 32 moves the meshing sleeve 34 back and forth, realizing the operation of engaging or disengaging the low-gear passive gear 12 and the high-gear passive gear 14 with the active double gear shaft 6.

[0049] Example 2 A tractor, including the rear-mounted PTO transmission box of the tractor.

[0050] The beneficial effects of the technical solution of this utility model are: The PTO transmission case provided in this application is a separate housing structure, mounted outside the tractor's rear axle, and internally contains a complete set of gears, brakes, and shifting mechanisms. Its core structure includes: 1. Main drive shaft (active double gear shaft 6): This is the power input shaft, which connects to the tractor gearbox.

[0051] 2. Driven shaft 9 and two gears (high-end driven gear 14 and low-end driven gear 12): These two gears can mesh with the main drive shaft respectively to achieve different output speeds.

[0052] 3. Gear shifting structure (shift fork assembly + engagement sleeve 34): By operating the shift fork 32, the engagement sleeve 34 is pushed to select the high gear or low gear.

[0053] 4. Braking device: used to cut off power and brake the PTO transmission box.

[0054] 5. Sealing and support structure (multiple bearings, oil seal 16, gear shaft end cover 4, etc.): ensures good sealing inside the transmission box, smooth operation, and no oil leakage.

[0055] These structural designs offer the following advantages: 1. Easy to disassemble and maintain: As it is an independent structure, it can be disassembled as a whole during maintenance without removing the rear axle.

[0056] 2. Compact structure and highly modular: suitable for matching different tractor models, facilitating serialization development.

[0057] 3. Smoother gear shifting: Equipped with a braking device, the drive shaft can stop quickly during gear shifting, preventing gear grinding.

[0058] 4. High scalability: If more speed options are needed, simply replace the gears or add components, resulting in low development costs.

[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although the utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this utility model.

[0060] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A tractor rear-mounted PTO transmission case, characterized in that, include: Transmission housing (1); The active double gear shaft (6) is rotatably mounted inside the transmission housing (1) via the first bearing (5); The passive shaft (9) is rotatably mounted inside the transmission housing (1) via two second bearings (15); A high-grade driven gear (14) and a low-grade driven gear (12) are mounted on the driven shaft (9). The high-grade driven gear (14) and the low-grade driven gear (12) are respectively installed in conjunction with the driven shaft (9) through a third bearing (11). The engagement sleeve (34) is used to selectively engage with the high-gear driven gear (14) or the low-gear driven gear (12) to achieve power output at different gears; A shift fork assembly is linked to the engagement sleeve (34) and is used to control the engagement sleeve (34) to switch between high and low gears; The power output shaft (18) is connected to the passive shaft (9) through the output shaft plug (17) and is sealed by the oil seal (16); A braking device is provided between the active double gear shaft (6) and the transmission housing (1) to realize the power cut-off and braking of the PTO transmission housing; The housing cover (3) is detachably disposed at the mounting port of the transmission housing (1); The gear shaft end cap (4) is detachably connected to the housing cover plate (3) and is used to seal one end of the active double gear shaft (6).

2. The tractor rear PTO housing of claim 1, wherein, The braking device includes a piston seat (21), a piston (23), a disc spring (24), a friction plate (26), a partition (27), a baffle (28), and a retaining ring (29). The piston seat (21) is connected to the transmission housing (1) by a first screw (20). The piston (23) is mounted on the piston seat (21), and a disc spring (24) for forming an axial restoring force is provided between the piston (23) and the piston seat (21). The piston (23) is sealed to the piston seat (21) and the transmission housing (1) by a first O-ring (22) and a second O-ring (25), respectively. The friction plate (26) and the partition plate (27) are respectively assembled between the active double gear shaft (6) and the transmission housing (1). The baffle plate (28) is assembled on the transmission housing (1) through the snap ring (29). The braking device moves to the left through the piston (23). The friction force formed by the friction plate (26), the partition plate (27) and the baffle plate (28) realizes the braking of the active double gear shaft (6).

3. The tractor rear PTO housing of claim 1, wherein, A spacer (10) is also provided on the passive shaft (9). The high-grade passive gear (14) and the low-grade passive gear (12) are axially positioned and locked by the spacer (10) and the locking nut (8).

4. The tractor rear PTO housing of claim 1, wherein, The shift fork assembly includes a shift fork shaft (31), a shift fork (32), and a shift fork head (33). The shift fork shaft (31) is fixed to the transmission housing (1) by a second screw (30). The shift fork (32) drives the engagement sleeve (34) to move through the shift fork head (33) to achieve high and low gear switching.

5. The tractor rear PTO housing of claim 1, wherein, The transmission housing (1) adopts a modular design and is detachably installed on the outside of the tractor's rear axle.

6. The tractor rear PTO housing of claim 1, wherein, The housing cover plate (3) is connected and fixed to the transmission box housing (1) by a positioning pin (2) and a third screw (13).

7. The tractor rear PTO housing of claim 1, wherein, The gear shaft end cap (4) is connected to the housing cover plate (3) by a fourth screw (7).

8. The tractor rear-mounted PTO transmission box according to claim 1, characterized in that, Both the first bearing (5) and the second bearing (15) are roller bearings.

9. The tractor rear PTO housing of claim 1, wherein, The third bearing (11) is a needle roller bearing.

10. A tractor characterised in that, Includes the tractor rear-mounted PTO transmission box as described in any one of claims 1 to 9.

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