A front PTO drive system, transmission case and tractor

Abstract

The application relates to a front PTO transmission system, a transmission case and a tractor. The PTO transmission system comprises a power output shaft and an input gear. The power output shaft can rotate around its own axis. The input gear is coaxially sleeved on one end of the power output shaft and is combined with the power output shaft through a hydraulic clutch and rotates with the power output shaft or is separated from the power output shaft. The application has the beneficial effects of realizing quick power output, high transmission efficiency, compact structure, high integration, small space occupation and light weight.

Description

Technical Field

[0001] This invention relates to the field of transmission system technology, specifically to a front-mounted PTO transmission system, a transmission box, and a tractor. Background Technology

[0002] The most common power output for tractors on the market is rear-mounted PTO output. Of course, there are also machines that require front-mounted power output. The current way to achieve this is to drive the tractor in reverse. Reverse driving greatly reduces the comfort and handling performance of the tractor, and some models cannot achieve reverse driving due to their small overall size.

[0003] Currently, most transmissions for front power take-off units in the domestic market use electromagnetic clutches, which have complex structures, increased machine weight, and significant transmission efficiency losses. Alternatively, they may incorporate deceleration and control into the same gearbox, resulting in complex gearbox structures, large space requirements, and inconvenient operation. Summary of the Invention

[0004] The technical problem to be solved by the present invention is to provide a front-mounted PTO transmission system, a transmission box and a tractor, in order to solve the problems in the prior art.

[0005] The technical solution of the present invention to solve the above-mentioned technical problems is as follows:

[0006] A front-mounted PTO drive system includes a power output shaft and an input gear. The power output shaft is rotatable about its own axis. The input gear is coaxially mounted on one end of the power output shaft and is engaged with the power output shaft via a hydraulic clutch, rotating with the power output shaft or disengaging from the power output shaft.

[0007] The beneficial effects of this invention are: during transmission, power is input through the input gear, which then engages with the power output shaft via a hydraulic clutch and rotates together with the power output shaft, achieving rapid power output; or it can disengage from the power output shaft, stopping transmission. The structure is simple and the design is reasonable. This invention can achieve rapid power output, has high transmission efficiency, and its structure is compact, highly integrated, occupies little space, and is lightweight.

[0008] Based on the above technical solution, the present invention can be further improved as follows.

[0009] Furthermore, the hydraulic clutch includes a hydraulic drive mechanism and a friction plate assembly. One end of the input gear extends toward the other end of the power output shaft and forms a mounting cavity with the power output shaft. The friction plate assembly is installed on the power output shaft at a position corresponding to the mounting cavity and is drively connected to one end of the power output shaft and one end of the input gear, respectively. The hydraulic drive mechanism is used to drive the friction plate assembly to engage or disengage the power output shaft and the input gear.

[0010] The beneficial effect of adopting the above-mentioned further solution is that during transmission, the friction plate assembly is driven by the hydraulic drive mechanism to engage or disengage the power output shaft and the input gear, thereby realizing the transmission or stopping of power. The transmission efficiency is high, and the structure is simple and occupies a small volume.

[0011] Furthermore, the friction plate assembly includes multiple friction plates and multiple steel plates. The multiple friction plates and multiple steel plates are sequentially and alternately coaxially sleeved on one end of the power output shaft along the axial direction of the power output shaft, and can slide along the axial direction of the power output shaft respectively. The inner side of each of the multiple friction plates is provided with internal teeth that mesh with the external teeth on one end of the power output shaft, and the outer side of each of the multiple steel plates is provided with external teeth that mesh with the internal teeth on the inner side of one end of the input gear.

[0012] The beneficial effect of adopting the above-mentioned further solution is that during transmission, multiple friction plates mesh with the power output shaft, and multiple steel plates mesh with the input gear. At the same time, the hydraulic drive mechanism squeezes the multiple friction plates and multiple steel plates, and the friction between the multiple friction plates and multiple steel plates is used to realize the engagement of the power output shaft and the input gear, thereby realizing the transmission of power from the input gear to the power output shaft; or the multiple friction plates and multiple steel plates are separated, thereby separating the power output shaft and the input gear, realizing the transmission or stopping of power. The transmission efficiency is high, and the structure is simple and occupies a small volume.

[0013] Furthermore, the hydraulic drive mechanism includes an oil supply assembly, a cylinder, a piston, and a return member. The cylinder is coaxially fixedly sleeved on the power output shaft. The piston is coaxially slidably sleeved on the power output shaft, located between the friction plate assembly and the cylinder, and forms an oil chamber between the piston, the cylinder, and the power output shaft. The oil supply assembly communicates with the oil chamber and is used to supply oil to the oil chamber to push the piston to move to engage the power output shaft and the input gear, or to return oil from the oil chamber and the piston returns to its original position under the action of the return member to separate the power output shaft and the input gear.

[0014] The beneficial effect of adopting the above-mentioned further solution is that during transmission, oil is supplied to the oil chamber through the oil supply assembly, which causes the oil to push the piston to move and squeeze the friction plate assembly, thereby making the power output shaft and the input gear engage. The power output shaft rotates with the input gear to realize the output of power; or, the oil supply assembly stops supplying oil, the piston returns to its original position under the action of the return component, and the oil in the oil chamber flows back to the oil supply assembly, stopping the transmission. The transmission efficiency is high, and the structure is simple and occupies a small volume.

[0015] Furthermore, the power output shaft has a structure that is thick at one end and thin at the other end, and a cavity is provided on its thick end. The end of the cavity away from the input gear is open, and the friction plate assembly is located at the thick end of the power output shaft. The return member includes a plurality of springs, which are evenly distributed in the cavity along the circumference of the power output shaft. They extend along the axial direction of the power output shaft, and one end of each spring extends to the outside of the open end of the cavity and abuts against the piston.

[0016] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The special structure of the power output shaft is used to realize the reasonable layout of each component. At the same time, the spring force is used to realize the piston's rapid and automatic return, which is convenient and quick.

[0017] Furthermore, the other end of the power output shaft is provided with an oil supply channel, one end of which is connected to the oil chamber; an oil supply device is fixedly installed on the outside of the power output shaft, the oil supply device is provided with an annular cavity, and the power output shaft is also provided with an oil inlet channel connecting the oil supply channel and the annular cavity; the oil supply device is provided with an oil inlet, which is connected to the oil supply assembly.

[0018] The advantages of adopting the above-mentioned further solution are that the structure is simple and the design is reasonable. The oil supply component supplies oil to the oil supply device, and at the same time the oil supply device supplies oil to the oil supply channel, ensuring normal oil supply without affecting the rotation of the power output shaft.

[0019] The present invention relates to a transmission housing, comprising a housing and a front-mounted PTO transmission system as described above, wherein the input gear is located within the housing and is fixedly connected to one end of a coupling; the power output shaft is located within the housing and its other end extends outside the housing.

[0020] The advantages of adopting the above-mentioned further solutions are that the structure is simple, the design is reasonable, the various components are integrated into one body using the shell, the integration is high, the space occupied is small, and the appearance is neat and beautiful.

[0021] Furthermore, the oil supply assembly includes a hydraulic gear pump assembly, which is fixedly installed inside the housing. The hydraulic gear pump assembly meshes with the input gear through a transmission gear and communicates with the oil chamber, for delivering the oil contained in the housing to the oil chamber.

[0022] The beneficial effects of adopting the above-mentioned further scheme are that, during transmission, on the one hand, the input gear transmits power to the hydraulic gear pump unit through the transmission gear, enabling the hydraulic gear pump unit to operate normally and saving energy; on the other hand, the hydraulic gear pump unit delivers the oil in the housing to the oil chamber, which is reasonably designed, does not require an additional oil tank, and occupies little space.

[0023] Furthermore, the housing is also provided with a breathing port, and a respirator is installed at the breathing port for depressurization.

[0024] The advantages of adopting the above-mentioned further solutions are that the structure is simple, the design is reasonable, and excessive pressure inside the shell is avoided.

[0025] The present invention also relates to a tractor, including the transmission box as described above.

[0026] The advantages of adopting the above-mentioned further solution are that it can achieve rapid power output, high transmission efficiency, and has a compact structure, high integration, small space occupation, and light weight. Attached Figure Description

[0027] Figure 1 This is a schematic diagram of the structure of the present invention;

[0028] Figure 2 for Figure 1 A magnified view of A in the middle.

[0029] The attached diagram lists the components represented by each number as follows:

[0030] 1. Power take-off shaft; 2. Input gear; 3. Friction plate; 4. Steel plate; 5. Cylinder block; 6. Piston; 7. Spring; 8. Oil supply channel; 9. Oil feeder; 10. Oil inlet channel; 11. Housing; 12. Hydraulic gear pump set; 13. Transmission gear; 14. Coupling; 15. Breather valve; 16. Sealing cover; 17. Sealing plug. Detailed Implementation

[0031] The principles and features of the present invention are described below with reference to the accompanying drawings and specific embodiments. The examples given are only for explaining the present invention and are not intended to limit the scope of the present invention.

[0032] Example 1

[0033] like Figure 1 and Figure 2 As shown, the present invention provides a front-mounted PTO transmission system, including a power output shaft 1 and an input gear 2. The power output shaft 1 can rotate around its own axis; the input gear 2 is coaxially mounted on one end of the power output shaft 1 and is engaged with the power output shaft 1 through a hydraulic clutch and rotates with the power output shaft 1 or is separated from the power output shaft 1.

[0034] During transmission, power is input through input gear 2, which then engages with power output shaft 1 via a hydraulic clutch and rotates together with power output shaft 1 to achieve rapid power output; or it can disengage from power output shaft to stop transmission. The structure is simple and the design is reasonable.

[0035] This embodiment can achieve rapid power output, high transmission efficiency, and has a compact structure, high integration, small footprint, and light weight.

[0036] The PTO mentioned above refers to power output.

[0037] Example 2

[0038] Based on Embodiment 1, in this embodiment, the hydraulic clutch includes a hydraulic drive mechanism and a friction plate assembly. One end of the input gear 2 extends towards the other end of the power output shaft 1, forming a mounting cavity with the power output shaft 1. That is, the input gear 2 has a cylindrical structure with one end closed and the other end open, and a circular hole is provided at the center of its closed end. This circular hole is rotatably connected to the power output shaft 1 through a bearing. The friction plate assembly is installed in the corresponding mounting cavity of the power output shaft 1 and is connected to one end of the power output shaft 1 and one end of the input gear 2 respectively. The hydraulic drive mechanism is used to drive the friction plate assembly to engage or disengage the power output shaft 1 and the input gear 2.

[0039] During transmission, the friction plate assembly is driven by a hydraulic drive mechanism to engage or disengage the power output shaft 1 and the input gear 2, thereby achieving power transmission or stopping. It has high transmission efficiency, simple structure, and small footprint.

[0040] In addition to the above-described embodiments, the hydraulic clutch can also employ other structures, such as a hydraulic drive mechanism and a gear one. A gear two is coaxially fixedly sleeved on the power output shaft 1. This gear has inner teeth on its inner side and outer teeth on its outer side, and is slidably connected to and meshes with the gear two. The hydraulic drive mechanism can drive the gear one to slide on the gear two at all times, and the gear one can slide to engage or disengage with the input gear 2.

[0041] Example 3

[0042] Based on Embodiment 2, in this embodiment, the friction plate assembly includes multiple friction plates 3 and multiple steel plates 4. The multiple friction plates 3 and multiple steel plates 4 are sequentially and alternately coaxially sleeved on one end of the power output shaft 1 along the axial direction of the power output shaft 1, and can slide along the axial direction of the power output shaft 1 respectively. The inner side of the multiple friction plates 3 is provided with internal teeth that mesh with the external teeth on one end of the power output shaft 1, and the outer side of the multiple steel plates 4 is provided with external teeth that mesh with the internal teeth on the inner side of one end of the input gear 2.

[0043] During transmission, multiple friction plates 3 mesh with the power output shaft 1, and multiple steel plates 4 mesh with the input gear 2. Simultaneously, a hydraulic drive mechanism squeezes the multiple friction plates 3 and multiple steel plates 4, utilizing the friction between the multiple friction plates 3 and multiple steel plates 4 to achieve the engagement of the power output shaft 1 and the input gear 2, thereby transmitting power from the input gear 2 to the power output shaft 1; or it can separate the multiple friction plates 3 and multiple steel plates 4, thereby separating the power output shaft 1 and the input gear 2, achieving the transmission or stopping of power. It has high transmission efficiency, simple structure, and small footprint.

[0044] Preferably, in this embodiment, each friction plate 3 has an annular plate structure, with internal teeth on its inner side along its circumference, and the internal teeth mesh with the external teeth on the power output shaft 1.

[0045] Preferably, in this embodiment, each steel plate 4 has an annular plate structure, with external teeth on its inner side along its circumference, and the external teeth mesh with the internal teeth on the input gear 2.

[0046] In addition to the above-described embodiments, a gear that meshes with the internal teeth on multiple friction plates 3 can also be fixedly mounted on the power output shaft 1.

[0047] Example 4

[0048] Based on any one of Embodiments 2 to 3, in this embodiment, the hydraulic drive mechanism includes an oil supply assembly, a cylinder 5, a piston 6, and a return component. The cylinder 5 is coaxially fixedly sleeved on the power output shaft 1. The piston 6 is coaxially slidably sleeved on the power output shaft 1, located between the friction plate assembly and the cylinder 5, and forms an oil chamber between the piston 6, the cylinder 5, and the power output shaft 1. The oil supply assembly communicates with the oil chamber and is used to supply oil to the oil chamber to push the piston 6 to move to engage the power output shaft 1 and the input gear 2, or to return oil from the oil chamber and the piston 6 returns to its original position under the action of the return component to separate the power output shaft 1 and the input gear 2.

[0049] During transmission, oil is supplied to the oil chamber through the oil supply assembly, causing the oil to push the piston 6 to move and squeeze the friction plate assembly, thereby engaging the power output shaft 1 and the input gear 2. The power output shaft 1 rotates with the input gear 2, realizing the output of power. Alternatively, the oil supply assembly stops supplying oil, and the piston 6 returns to its original position under the action of the return component. At the same time, the oil in the oil chamber flows back to the oil supply assembly, stopping the transmission. The transmission efficiency is high, and the structure is simple and occupies a small volume.

[0050] Preferably, in this embodiment, the piston 6 is a cylindrical structure with one end closed and the other end open, and its closed end is close to the friction plate assembly, while the inner wall of its open end is in contact with the edge of the cylinder 5 and a sealing ring is provided between the two.

[0051] In addition, the piston 6 has a through hole at the center of its closed end for the power output shaft 1 to pass through, and an annular protrusion on its closed end, which facilitates the compression of the friction plate assembly.

[0052] In addition to the above-described embodiments, the hydraulic drive mechanism can also be implemented in other ways. For example, the hydraulic drive mechanism includes a piston and a hydraulic cylinder. The piston is coaxially mounted on the power output shaft 1, and the hydraulic cylinder is fixedly installed. Its telescopic end moves along the axial direction of the power output shaft 1 and is fixedly connected to the piston. In use, the hydraulic cylinder extends and retracts, driving the piston to squeeze or release the friction plate 3 and the steel plate 4.

[0053] Example 5

[0054] Based on embodiment 4, in this embodiment, the power output shaft 1 has a structure that is thick at one end and thin at the other end, and a cavity is provided on its thick end. The end of the cavity away from the input gear 2 is open, and the friction plate assembly is located at the thick end of the power output shaft 1. The return component includes multiple springs 7, which are evenly distributed in the cavity along the circumference of the power output shaft 1. They extend along the axial direction of the power output shaft 1, and one end of each spring extends to the outside of the open end of the cavity and abuts against the piston 6.

[0055] The scheme has a simple structure and reasonable design. It utilizes the special structure of the power output shaft 1 to achieve a reasonable layout of each component. At the same time, it uses the elastic force of the spring 7 to achieve the rapid and automatic return of the piston 6, which is convenient and quick.

[0056] Example 6

[0057] Based on embodiment 4, in this embodiment, the other end of the power output shaft 1 is provided with an oil supply channel 8, one end of which is connected to the oil cavity; an oil supply device 9 is fixedly installed on the outside of the power output shaft 1, the oil supply device 9 is provided with an annular cavity, and the power output shaft 1 is also provided with an oil inlet channel 10 connecting the oil supply channel 8 and the annular cavity; the oil supply device 9 is provided with an oil inlet, which is connected to the oil supply assembly.

[0058] The scheme has a simple structure and reasonable design. It supplies oil to the oiler 9 through the oil supply component, and at the same time, the oiler 9 supplies oil to the oil supply channel 8, ensuring normal oil supply without affecting the rotation of the power output shaft 1.

[0059] Preferably, in this embodiment, during processing, the other end of the oil supply channel 8 is open to facilitate the processing of the oil supply channel 8, and a sealing plug 17 is fixedly installed at the other end of the oil supply channel 8.

[0060] In addition to the above-described embodiments, the oil supply assembly can also be connected to the oil chamber via a hose. However, this method is prone to pipe tangling, which can easily lead to pipe breakage and requires a large amount of space.

[0061] Example 7

[0062] Based on the above embodiments, this embodiment also provides a transmission box, including a housing 11, and a front-mounted PTO transmission system as described above. The input gear 2 is located inside the housing 11 and is rotatably connected to one end of the housing 11 via a bearing, and is fixedly connected to one end of the coupling 14. The power output shaft 1 is located inside the housing 11, and its other end extends outside the housing 11.

[0063] The solution has a simple structure and reasonable design. It integrates all components into one unit using the shell 11, resulting in high integration, small space occupation, and a neat and beautiful appearance.

[0064] Preferably, in this embodiment, the coupling 14 is typically used to connect a power output device, such as an engine.

[0065] In addition, the other end of the power output shaft 1 is used to connect to the device to be driven.

[0066] In addition to the above-described embodiments, the input gear 2 can also be installed in other ways. For example, a mounting bracket is fixedly installed inside the housing 11, and the input gear 2 is mounted on the mounting bracket by rotating through a bearing, that is, the input gear 2 is suspended and installed inside the housing 11.

[0067] Example 8

[0068] Based on Embodiment 7, in this embodiment, the oil supply assembly includes a hydraulic gear pump assembly 12, which is fixedly installed inside the housing 11. It meshes with the input gear 2 through the transmission gear 13 and communicates with the oil chamber to deliver the oil contained in the housing 11 to the oil chamber.

[0069] During transmission, on the one hand, the input gear 2 transmits power to the hydraulic gear pump group 12 through the transmission gear 13, enabling the hydraulic gear pump group 12 to operate normally and saving energy; on the other hand, the hydraulic gear pump group 12 delivers the oil in the housing 11 to the oil chamber. The design is reasonable, no additional oil tank is required, and it occupies little space.

[0070] Preferably, in this embodiment, the hydraulic gear pump assembly 12 includes a gear pump and a solenoid valve. The gear pump includes a meshing hydraulic pump drive gear and a hydraulic pump driven gear. A transmission gear 13 is fixedly mounted on the drive gear and meshes with the input gear 2. An oil filter is provided at the oil inlet of the gear pump. The solenoid valve is connected to the gear pump, and the solenoid valve is controlled by a switch and a power supply stroke control circuit.

[0071] In addition, the aforementioned shell 11 is composed of two half-shells joined together, which facilitates installation.

[0072] In addition to the above-described embodiments, the oil supply assembly can also be provided with a separate oil tank. In this case, the hydraulic gear pump assembly 12 is connected to the bottom of the oil tank, and the oil in the oil tank is delivered to the oil chamber through the hydraulic gear pump assembly 12.

[0073] In addition, the aforementioned fuel tank can be located inside or outside the housing 11. Regardless of the installation method, it occupies more space than the above-mentioned solution.

[0074] After the housing 11 is installed, in order to reasonably arrange the hydraulic gear pump group 12, an oil passage can also be set on the corresponding part of the housing 11. Both ends of the oil passage are open, one end is connected to the oil outlet of the hydraulic gear pump group 12, and the other end is connected to the oil inlet on the oil supply device 9. The arrangement is reasonable and occupies little space.

[0075] Example 9

[0076] Based on embodiment 8, in this embodiment, the housing 11 is also provided with a breathing port, and a respirator is installed at the breathing port for depressurization.

[0077] The solution has a simple structure and a reasonable design, which avoids excessive pressure inside the shell 11.

[0078] Preferably, in this embodiment, the respirator includes a breathing valve 15 and a sealing cap 16. The breathing valve 15 is threadedly connected to the breathing port and has a pressure relief chamber inside it. One end of the breathing valve 15 is open inside the housing 11, and multiple pressure relief ports communicating with the pressure relief chamber are provided on the part of the breathing valve 15 located outside the housing 11.

[0079] In addition, the sealing cover 16 is slidably sleeved on the breathing valve 15, and is pressed tightly against the housing 11 by the breathing valve 15. That is, the end of the sealing cover 16 close to the housing 11 is open, and the end away from the housing 11 is provided with a round hole for the breathing valve 15 to pass through. The size of the other end of the breathing valve 15 is larger than the size of the round hole. The sealing cover 16 is provided with a groove, and multiple pressure relief holes communicating with the interior of the sealing cover 16 are provided in the groove at intervals.

[0080] Preferably, in this embodiment, a sealing ring is provided between the open end of the sealing cap 16 and the housing 11.

[0081] Preferably, in this embodiment, the groove is an annular groove, and a sealing ring is fitted inside the annular groove. During pressure relief, the gas path inside the housing 11 is: the open end of the breather valve 15 - pressure relief chamber - pressure relief port - pressure relief hole - outside of the housing 11.

[0082] Example 10

[0083] Based on the above embodiments, this embodiment also provides a tractor, including the transmission box as described above.

[0084] This solution enables rapid power output, has high transmission efficiency, and features a compact structure, high integration, small footprint, and light weight.

[0085] The working principle of this invention is as follows:

[0086] Power is transmitted to input gear 2 via coupling 14. Input gear 2 drives hydraulic gear pump 12 to rotate via transmission gear 13. At the same time, hydraulic gear pump 12 sends oil from housing 11 to oil chamber, causing oil to push piston 6 close to friction plate 3 and squeeze friction plate 3 and steel plate 4. The friction between friction plate 3 and steel plate 4 is used to connect power output shaft 1 and input gear 2, so that power output shaft 1 rotates with input gear 2 to send power out from the other end of power output shaft 1, completing the rapid transmission of power. At this time, multiple springs 7 are in a compressed state.

[0087] After the power transmission is completed, the piston 6 returns to its original position under the elastic force of multiple springs 7, causing multiple friction plates 3 and multiple steel plates 4 to separate, thereby realizing the separation of the power output shaft 1 and the input gear 2; at this time, the oil in the oil chamber returns to the housing 11 along the original path.

[0088] It should be noted that the arrows in the attached diagram only indicate the direction of oil flow during power transmission.

[0089] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A front-mounted PTO drive system, characterized in that: The device includes a power output shaft (1) and an input gear (2). The power output shaft (1) is rotatable about its own axis. The input gear (2) is coaxially mounted on one end of the power output shaft (1) and engages with the power output shaft (1) via a hydraulic clutch, rotating with or separating from the power output shaft (1). The hydraulic clutch includes a hydraulic drive mechanism and a friction plate assembly. One end of the input gear (2) extends toward the other end of the power output shaft (1) and forms a mounting cavity with the power output shaft (1). The friction plate assembly is mounted on the power output shaft (1) at the location corresponding to the mounting cavity and engages with the power output shaft (1) at the location corresponding to the power output shaft (1). One end of the shaft (1) is connected to one end of the input gear (2) for transmission; the hydraulic drive mechanism is used to drive the friction plate assembly to engage or disengage the power output shaft (1) and the input gear (2); the friction plate assembly includes multiple friction plates (3) and multiple steel plates (4), each friction plate (3) is an annular plate structure, each steel plate (4) is an annular plate structure, the multiple friction plates (3) and the multiple steel plates (4) are sequentially and alternately coaxially sleeved on one end of the power output shaft (1) along the axial direction of the power output shaft (1), and can slide along the axial direction of the power output shaft (1); the inner side of the multiple friction plates (3) is respectively provided with a connection to the power output shaft (1) 1) External teeth meshing with internal teeth on one end; external teeth meshing with internal teeth on the outer side of multiple steel plates (4) respectively; the hydraulic drive mechanism includes an oil supply assembly, a cylinder (5), a piston (6) and a return component; the cylinder (5) is coaxially fixedly sleeved on the power output shaft (1); the piston (6) is coaxially slidably sleeved on the power output shaft (1), located between the friction plate assembly and the cylinder (5), and forms an oil cavity between the piston (5) and the power output shaft (1); the oil supply assembly communicates with the oil cavity and is used to supply oil to the oil cavity to push the piston (6) to move to engage the power output shaft (1) and The input gear (2), or the oil chamber returns oil and the piston (6) returns to its original position under the action of the return member to separate the power output shaft (1) and the input gear (2); the power output shaft (1) has a structure that is thick at one end and thin at the other end, and a cavity is provided on its thick end. The cavity is open at one end away from the input gear (2), and the friction plate assembly is located at the thick end of the power output shaft (1); the return member includes a plurality of springs (7), which are evenly distributed in the cavity along the circumference of the power output shaft (1). They extend along the axial direction of the power output shaft (1) respectively, and one end of each spring extends to the outside of the open end of the cavity and abuts against the piston (6).

2. The front-mounted PTO drive system according to claim 1, characterized in that: The other end of the power output shaft (1) is provided with an oil supply channel (8), one end of which is connected to the oil cavity; an oil supply device (9) is fixedly installed on the outside of the power output shaft (1), and an annular cavity is provided inside the oil supply device (9). The power output shaft (1) is also provided with an oil inlet channel (10) that connects the oil supply channel (8) and the annular cavity; an oil inlet is provided on the oil supply device (9), and the oil inlet is connected to the oil supply assembly.

3. A transmission box, comprising a housing (11), characterized in that: It also includes the front-mounted PTO drive system as described in claim 1 or 2, wherein the input gear (2) is located inside the housing (11) and is fixedly connected to one end of the coupling (14); the power output shaft (1) is located inside the housing (11) and its other end extends outside the housing (11).

4. The transmission box according to claim 3, characterized in that: The oil supply assembly includes a hydraulic gear pump assembly (12), which is fixedly installed inside the housing (11). It meshes with the input gear (2) through a transmission gear (13) and communicates with the oil chamber to deliver the oil contained in the housing (11) to the oil chamber.

5. The transmission box according to claim 4, characterized in that: The housing (11) is also provided with a breathing port, and a respirator is installed at the breathing port for depressurization.

6. A tractor, characterized in that: Includes the transmission box as described in any one of claims 3-5.

Images