Friction type power takeoff

Abstract

The application provides a friction type power take-off and relates to the field of power take-off.The scheme is as follows: a box body is arranged, an output shaft is rotatably arranged in the box body, an output gear is rotatably arranged on the output shaft, a clutch is connected with the output gear, the clutch is connected with the output shaft, an input shaft is further arranged, an input gear is arranged on the input shaft through a bearing, a spline piston is key-connected on the input shaft, the spline piston can be key-connected with an inner hole of the input gear, an elastic element is arranged between one end of the spline piston and the corresponding bearing, an oil cavity is communicated with the other end of the spline piston, the oil cavity is arranged on an input end cover, an oil channel is further arranged on the input end cover, the oil channel is communicated with the oil cavity, and the oil cavity is connected with an oil source.The application can avoid the rotation of the output gear after gear shifting and reduce energy consumption.

Description

Technical Field

[0001] This invention relates to the field of power take-off devices, and more particularly to a friction-type power take-off device. Background Technology

[0002] A power take-off (PTO) is a set of transmission gears, also known as a power output device. It is generally composed of a gearbox and a clutch and is connected to the transmission via gears. Its main function is to obtain power from the vehicle chassis system and then, through its own conversion, transmit the power to the vehicle's oil pump system via a drive shaft, thereby controlling the superstructure to complete its specific functions. The PTO is usually an auxiliary device installed on the outside of the transmission. It obtains power from a certain gear in the transmission, and the connection or disconnection of this power is controlled by a solenoid valve in the driver's cab.

[0003] Chinese utility model patent CN205592373U discloses a friction-type gear shifting power take-off (PTO), comprising a power input end, a gear shifting input end, a power output end, a gear shifting output end, a control unit, a connecting mechanism, and a reset mechanism. The power input end and the gear shifting input end cooperate with each other. The control unit and the gear shifting output end are connected via the connecting mechanism. The gear shifting output end is connected to the power output end. The gear shifting output end can move accordingly in the axial direction of the power output end according to the movement of the control unit, but cannot rotate relative to the power output end. The gear shifting output end and the gear shifting input end are coaxial. The reset mechanism is a reset elastic element and is disposed between the control unit and the power output end. A friction plate is fixedly disposed at one end of the gear shifting input end. A friction plate is fixedly disposed at one end of the gear shifting output end. The friction plate at one end of the gear shifting output end and the friction plate at one end of the gear shifting input end are in contact with each other / away from each other. When disengaging from gear, the solenoid valve is closed, the air pressure on the piston disappears, and the shift spindle moves away from the output gear to the starting position under the elastic force of the reset elastic element. At the same time, it drives the sliding sleeve and piston to move away from the output gear to the starting position. After the sliding sleeve moves away from the output gear, the friction between the two friction plates decreases until it disappears. The output gear, which is driven to rotate by the input gear, gradually becomes unable to drive the sliding sleeve to rotate, and the rotation of the sliding sleeve gradually stops. At the same time, the rotation of the shift spindle and the output shaft gradually stops, and the output flange stops outputting.

[0004] This technical solution is low-cost and uses friction-type gear shifting, which can achieve smooth and reliable gear shifting even at high speeds, improving the performance of the transmission power take-off. However, after disengaging, the input gear still drives the output gear to idle, resulting in energy loss, affecting the effective utilization of the vehicle's energy, and increasing the wear of the output gear, thus shortening its service life. Summary of the Invention

[0005] In order to overcome the problem of energy consumption caused by the output gear still spinning after disengaging from the gear in the prior art, the present invention provides a friction-type power take-off that can prevent the output gear from rotating after disengaging from the gear, thereby reducing energy consumption.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is as follows: a friction-type power take-off (PTO), including a housing, an output shaft rotatably disposed within the housing, an output gear rotatably disposed on the output shaft, a clutch connected to the output gear, the clutch being connected to the output shaft, and an input shaft, an input gear disposed on the outer circumference of the input shaft via a bearing, the output gear being able to rotate under the drive of the input gear, a spline piston keyed to the input shaft, the spline piston being able to move along the input shaft inside the input gear, the spline piston being able to be keyed to the inner hole of the input gear, an elastic element disposed between one end of the spline piston and a corresponding bearing, and an oil cavity formed between the other end of the spline piston and an input end cover, the input shaft, and the input gear, an oil inlet hole disposed on the input end cover, the oil inlet hole communicating with the oil cavity, the oil inlet hole being connected to an oil source, the oil source being able to provide hydraulic oil. The left and right movement of the spline piston can be controlled by the action of hydraulic oil and elastic elements, thereby realizing the connection and disengagement of the input shaft and the input gear. When disengaging from gear, the input shaft can be controlled to disengage from the output gear, so that the output gear no longer transmits power, thereby reducing energy loss.

[0007] Furthermore, the input gear is provided with a pressure relief oil passage. One end of the pressure relief oil passage is connected to the oil chamber and the connection position is close to the spline piston, while the other end of the pressure relief oil passage is connected to the housing. The pressure relief oil passage can prevent the oil pressure in the oil chamber from becoming too high, which would increase the friction between the components and damage them.

[0008] Furthermore, the input shaft is coaxially connected to the drive shaft, and an outer coupling blade is provided on the outer circumference of the input shaft. The outer coupling blade is located in the oil cavity, and an inner coupling blade is provided in the inner hole of the input gear. Through the coupling effect of the inner and outer coupling blades, the input gear can be pre-rotated before the input shaft connects with the input gear, giving it a certain speed, reducing the impact when the input shaft meshes with the input gear, providing a smoother connection to the input gear, and extending the service life of the input gear.

[0009] Furthermore, the outer cylindrical shaft of the splined piston is provided with a fourth spline, and the inner bore of the input gear is provided with a second spline. The fourth spline and the second spline can mesh, and both the fourth spline and the second spline are provided with chamfers. The chamfers facilitate smooth meshing of the fourth spline and the second spline, further reducing impact.

[0010] Furthermore, the input end cover is also provided with a fine oil outlet hole, which communicates with the oil chamber. The diameter of the fine oil outlet hole is smaller than the diameter of the pressure relief oil passage. The fine oil outlet hole allows the low-pressure hydraulic oil in the oil chamber to be discharged when the gear is disengaged, preventing the elastic element from being triggered.

[0011] Furthermore, it also includes an intermediate shaft, on which an intermediate gear is rotatably mounted. The intermediate gear meshes with both the input gear and the output gear. Both ends of the intermediate shaft are mounted on the housing. By including the intermediate shaft and intermediate gear, the wheelbase is increased to avoid interference with the gearbox, and the rotation of the output shaft is made the same as that of the input shaft, which facilitates layout.

[0012] Furthermore, the splined piston is provided with a third sealing ring and a second sealing ring sequentially from the outside to the inside at its end in the oil chamber. The second and third sealing rings reduce the leakage of pressurized oil in the oil chamber, ensuring that the oil chamber maintains high pressure.

[0013] Furthermore, a first oil seal is provided between the input end cover and the input shaft, and a first sealing ring is provided between the input end cover and the input gear. This further ensures that high pressure is formed in the oil chamber.

[0014] Furthermore, a first bearing and a second bearing are provided at both ends of the input gear, and both the first bearing and the second bearing are housed within the housing. The first bearing and the second bearing provide stable support for the input gear from the housing.

[0015] Furthermore, a third bearing and a fourth bearing are provided between the input shaft and the input gear. The third bearing is located within the oil chamber, and elastic elements are provided between the fourth bearing and the splined piston. The third and fourth bearings are positioned on the input shaft by snap rings. The third and fourth bearings provide stable support for the input shaft by the input gear.

[0016] As can be seen from the above technical solutions, the present invention has the following advantages:

[0017] This solution provides a friction-type power take-off (PTO) that controls the left and right movement of the spline piston through the action of hydraulic oil and elastic elements, thereby enabling the connection and disengagement of the input shaft and input gear. It can also control the disengagement of the input shaft and output gear when disengaging from gear, preventing the output gear from transmitting power and reducing energy loss. A pressure relief oil passage prevents excessive oil pressure in the oil chamber, which increases friction between components and damages them. The coupling effect of internal and external coupling blades allows the input gear to rotate in advance before the input shaft connects to the input gear, ensuring it has a certain speed, reducing the impact during engagement, and providing a smoother connection, extending the service life of the input gear. Chamfering facilitates smooth engagement of the fourth and second splines, further reducing impact. A fine oil outlet allows low-pressure hydraulic oil in the oil chamber to be discharged when disengaging from gear, preventing damage to the elastic elements. The first sealing ring, first oil seal, second sealing ring, and third sealing ring reduce leakage of pressurized oil in the oil chamber, ensuring high-pressure areas. The intermediate shaft and intermediate gear increase the wheelbase to avoid interference with the gearbox and ensure the output shaft rotates in the same direction as the input shaft, facilitating layout. Attached Figure Description

[0018] To more clearly illustrate the technical solution of the present invention, the accompanying drawings used in the description will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0019] Figure 1 This is a structural schematic diagram of a specific embodiment of the present invention.

[0020] Figure 2 This is a schematic diagram of the input shaft and input gear in the gear-engaged state according to a specific embodiment of the present invention.

[0021] Figure 3 This is a schematic diagram of the input shaft in a specific embodiment of the present invention.

[0022] Figure 4 This is a schematic diagram of the input gear in a specific embodiment of the present invention.

[0023] Figure 5 This is a schematic diagram of the spline piston in a specific embodiment of the present invention.

[0024] Figure 6 This is a schematic diagram of the assembly structure of the input gear and the input shaft in a specific embodiment of the present invention.

[0025] In the diagram, 1. Drive shaft, 2. Input shaft, 2001. External coupling blade, 2002. First spline, 3. First oil seal, 4. Input end cover, 40. Oil chamber, 41. Oil inlet, 42. Fine oil outlet, 43. First sealing ring, 5. First bearing, 6. Intermediate shaft, 7. Housing, 8. Intermediate bearing, 9. Intermediate gear, 10. Output gear, 11. Fifth bearing, 12. Output shaft, 13. Clutch, 14. Gear ring, 15. 16. Output end cap, 17. Sixth bearing, 18. Second bearing, 19. Input gear, 10. Pressure relief oil passage, 10. Inner coupling blade, 11. Second spline, 12. Second oil seal, 23. Fourth bearing, 24. Elastic element, 25. Spline piston, 26. Second sealing ring, 27. Third sealing ring, 28. Fourth spline, 29. Third spline, 20. Second snap ring, 20. Third bearing, 21. First snap ring. Detailed Implementation

[0026] To make the objectives, features, and advantages of this invention more apparent and understandable, the technical solutions of this invention will be clearly and completely described below with reference to the accompanying drawings of the specific embodiments. Obviously, the embodiments described below are only some embodiments of this invention, and not all embodiments. Based on the embodiments of this patent, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this patent.

[0027] The inventors discovered that in existing friction-type power take-offs, the transmission connection between the output gear and the output shaft is controlled by friction plates. After disengaging from gear, although the output gear no longer drives the output shaft to rotate, the input gear still drives the output gear to idle, resulting in energy loss and affecting the effective utilization of the vehicle's energy. Based on this, the embodiment of the present invention provided by the inventors can disconnect the transmission between the input shaft and the input gear when disengaging from gear, solving the problem of energy loss caused by the output gear still idling after disengaging from gear in the prior art.

[0028] like Figure 1As shown, this specific embodiment provides a friction-type power take-off (PTO), including a housing 7, a drive shaft 1, an output shaft 12, an output gear 10, an input shaft 2, and an input gear 18. The output shaft 12 is rotatably mounted inside the housing 7, and an output end cover 15 is also provided on the housing 7. The output shaft 12 rotatably extends out of the output end cover 15 via a sixth bearing 16. The output gear 10 is rotatably mounted on the output shaft 12, and a clutch 13 is connected to the output shaft 12. In this specific embodiment, the output shaft 12 is rotatably connected to the housing 7 via a fifth bearing 11 and a sixth bearing 16. The clutch 13 is a multi-plate clutch, which includes friction... Friction plates and steel plates mesh with the output gear 10, and the steel plates mesh with the gear ring 14. The gear ring 14 is fixedly connected to the output shaft 12. The friction plates and steel plates can be pressed together under the action of high-pressure oil or gas to achieve the engagement and transmission of the output gear 10 and the gear ring 14. An input gear 18 is set on the input shaft 2 through bearings. The output gear 10 can rotate under the drive of the input gear 18. A first bearing 5 and a second bearing 17 are set at both ends of the input gear 18. The first bearing 5 and the second bearing 17 are both set in the housing 7, and the first bearing 5 is positioned by the input end cover 4. A third bearing 24 and a fourth bearing 20 are set between the input shaft 2 and the input gear 18. The third bearing 24 and the fourth bearing 20 are respectively The input shaft 2 is positioned by the first snap ring 25 and the second snap ring 23. A splined piston 22 is keyed to the outer circumference of the input shaft 2. An elastic element 21 (in this specific embodiment, a spring) is provided between one end of the splined piston 22 and the third bearing 24. The other end of the splined piston 22 forms an oil cavity 40 between the input end cover 4, the input shaft 2, and the input gear 18. The third bearing 24 is located in the oil cavity 40. The splined piston 22 can move along the input shaft 2 inside the input gear 18. The splined piston 22 can be keyed to the inner hole of the input gear 18. Specifically, the inner and outer sides of the splined piston 22 are respectively provided with a third spline 224 and a fourth spline 223. The input shaft 2 is provided with a first spline 20. 02, the first spline 2002 meshes with the third spline 224, so that the spline piston 22 can rotate and move axially with the input shaft 2. The input gear 18 is provided with a second spline 183. When the gear is engaged, it meshes with the fourth spline 223 to realize the transmission connection between the input shaft 2 and the input gear 18. The spline piston 22 is provided with a third sealing ring 222 and a second sealing ring 221 from the outside to the inside at one end of the oil chamber 40. At the same time, a first oil seal 3 is provided between the input end cover 4 and the input shaft 2, and a second oil seal 19 is provided between the housing 7 and the input shaft 2. A first sealing ring 43 is used to seal between the input end cover 4 and the input gear 18 to ensure that a certain high pressure is formed in the oil chamber 40.The input end cover 4 is also provided with an oil inlet 41, which communicates with the oil chamber 40. The oil inlet 41 is connected to an oil source, which can provide high-pressure and low-pressure hydraulic oil. The high-pressure oil is used to push the spline piston 22, and the low-pressure oil is used for lubrication. In this specific embodiment, the oil source uses a combination of an oil pump and a throttle valve, which can change the oil supply pressure and flow rate. By injecting hydraulic oil and using the elastic element 21, the left and right movement of the spline piston 22 can be controlled, thereby realizing the connection and disengagement of the input shaft 2 and the input gear 18. When disengaging from gear 10, the input shaft 2 can be disengaged from the output gear 10, preventing the output gear 10 from transmitting power and thus reducing energy loss.

[0029] like Figure 2 As shown, in order to prevent excessive oil pressure in the oil chamber 40, a pressure relief oil passage 181 is provided on the input gear 18. One end of the pressure relief oil passage 181 is connected to the oil chamber 40 and the connection position is close to the spline piston 22. When the spline piston 22 moves to the right, the pressure relief oil passage 181 can connect to the oil chamber 40. The other end of the pressure relief oil passage 181 is connected to the housing 7. In this specific embodiment, multiple pressure relief oil passages 181 are provided. The pressure relief oil passages 181 can prevent excessive oil pressure in the oil chamber 40, which would increase friction between parts and damage the parts.

[0030] like Figures 2 to 6 As shown, in order to achieve a smooth connection between the input gear 18 and the input shaft 2 and reduce the impact between them, the input shaft 2 is coaxially connected to the drive shaft 1. An outer coupling blade 2001 is provided on the outer circumference of the input shaft 2 and is located in the oil cavity 40. An inner coupling blade 182 is provided in the inner hole of the input gear 18. Through the coupling effect of the inner and outer coupling blades, the input gear 18 can be rotated in advance before the input shaft 2 is connected to the input gear 18, so that it has a certain speed, reducing the impact when the input shaft 2 and the input gear 18 mesh, and connecting the input gear 18 more smoothly, thus extending the service life of the input gear 18. The fourth spline 223 and the second spline 183 are both provided with chamfers. By providing chamfers, the fourth spline 223 and the second spline 183 can mesh smoothly, further reducing the impact.

[0031] like Figure 2 As shown, in order to prevent the oil pressure in the oil chamber 40 from increasing and triggering the elastic element 21 when the gear is disengaged, a fine oil outlet hole 41 is also provided on the input end cover 4. The fine oil outlet hole 41 is connected to the oil chamber 40, and the diameter of the fine oil outlet hole 41 is smaller than the diameter of the pressure relief oil passage 181. When the gear is engaged, the oil volume is large and the oil pressure is high. Since the diameter of the fine oil outlet hole 42 is small, the oil output is slow and has little impact on the formation of high pressure in the oil chamber 40. The elastic element 21 can be compressed, and the spline piston 22 moves to the right to realize the connection between the input shaft 2 and the input gear 18. When the gear is disengaged, there is still oil entering the oil chamber 40. Through the fine oil outlet hole 42, the oil can flow out to the housing 7 without triggering the elastic element 21 and causing the spline piston 22 to move to the right.

[0032] like Figure 1 As shown, for ease of layout, this power take-off also includes an intermediate shaft 6, on which an intermediate gear 9 is rotatably mounted. An intermediate bearing 8 and an intermediate gear 9 are provided between the intermediate shaft 6 and the intermediate gear 9. The intermediate gear 9 meshes with the input gear 18 and the output gear 10 respectively. Both ends of the intermediate shaft 6 are mounted on the housing 7. By setting the intermediate shaft 6 and the intermediate gear 9, the wheelbase is increased to avoid interference with the gearbox. On the other hand, the output shaft 12 rotates in the same direction as the input shaft 2, which facilitates the layout.

[0033] The working process of this power take-off unit is as follows:

[0034] When shifting gears, a large flow of high-pressure oil continuously flows into the oil chamber 40 through the oil inlet 41. Due to the small diameter of the fine oil outlet 42, the oil cannot be discharged in time and gradually fills the oil chamber 40. It then enters the space between the outer coupling blade 2002 and the inner coupling blade 182 through the third bearing 24. The outer coupling blade 2002 agitates the oil, and the oil impacts the inner coupling blade 182, forming a coupling effect. This gradually drives the input gear 18 to rotate, which in turn causes the intermediate gear 9 and the output gear 10 to rotate. As the pressure in the oil chamber 40 continues to increase, it gradually overcomes the pressure of the elastic element 21 and pushes the spline piston 22 to move to the right. The fourth spline 223 engages with the second spline 183, and the power of the input shaft 2 is transmitted to the input gear 18 through the spline piston 22, and then to the intermediate gear 9 and the output gear 10. At this time, the clutch 13 is engaged to output the power through the gear ring 14 and the output shaft 12. The chamfer on the fourth spline 223 can ensure smooth spline engagement, and since the input gear 18 has been pre-rotated, the impact during spline engagement is also small. When the spline piston 22 moves to the right a sufficient distance, the pressure relief oil passage 181 is exposed, and the oil can flow back to the housing from the pressure relief oil passage 181 to prevent the pressure in the oil chamber 40 from being too high.

[0035] When the gear is disengaged, the clutch 13 disengages, the power between the output gear 10 and the gear ring 14 is interrupted, the oil inlet 41 resumes to flow with low flow and low pressure, the oil in the oil chamber 40 gradually flows out from the narrow oil outlet 42, the pressure in the oil chamber 40 decreases, the elastic element 21 pushes the spline piston 22 to the left, so that the fourth spline 223 disengages from the second spline 183, the power of the input shaft 2 cannot be transmitted to the input gear 18, the oil continues to decrease, the agitation of the oil by the outer coupling blade 2002 is weakened, the hydraulic coupling effect between the outer coupling blade 2002 and the inner coupling blade 182 is reduced, the input gear 18 stops rotating or rotates at a low speed, at this time the input gear 18, the intermediate gear 9 and the output gear 10 return to the state of no power, reducing energy loss.

[0036] In the off position, oil with a small flow rate and low pressure is introduced into the oil chamber 40 through the oil inlet 41, which is only used to lubricate the third bearing 24. Excess oil flows back to the housing 7 through the fine oil outlet 42.

[0037] As can be seen from the above specific embodiments, the present invention has the following beneficial effects:

[0038] 1. The left and right movement of the spline piston 22 can be controlled by the action of hydraulic oil and elastic element 21, thereby realizing the connection and disengagement of the input shaft 2 and the input gear 18. When the gear is disengaged, the input shaft 2 can be controlled to disengage from the output gear 10, so that the output gear 10 no longer transmits power, thereby reducing energy loss.

[0039] 2. The pressure relief oil passage 181 can prevent excessive oil pressure in the oil chamber 40, which would increase friction between parts and damage them.

[0040] 3. Through the coupling effect of the inner and outer coupling blades, the input gear 18 can be rotated in advance before the input shaft 2 is connected to the input gear 18, so that it has a certain speed, reducing the impact when the input shaft 2 and the input gear 18 mesh, and connecting to the input gear 18 more smoothly, thus extending the service life of the input gear 18.

[0041] 4. By setting a chamfer, the fourth spline 223 and the second spline 183 can be smoothly engaged, further reducing impact;

[0042] 5. The low-pressure hydraulic oil in the oil chamber 40 can be discharged through the fine oil outlet 41 when the gear is disengaged, preventing the elastic element 21 from being triggered.

[0043] 6. The leakage of pressurized oil in the oil chamber 40 is reduced by the first sealing ring 43, the first oil seal 3, the second sealing ring 221 and the third sealing ring 222 to ensure the high pressure zone;

[0044] 7. By setting intermediate shaft 6 and intermediate gear 9, the wheelbase is increased to avoid interference with the gearbox, and the output shaft 12 rotates in the same direction as the input shaft 2, which facilitates the layout.

[0045] The terms “upper,” “lower,” “outer,” “inner,” etc. (if present) in the specification, claims, and accompanying drawings of this invention are used to distinguish relative positional relationships and are not necessarily qualitative. It should be understood that such data can be interchanged where appropriate so that embodiments of the invention described herein can be implemented in orders other than those illustrated or described herein. Furthermore, the terms “comprising” and “having,” and any variations thereof, are intended to cover non-exclusive inclusion.

[0046] The above description of the disclosed embodiments enables those skilled in the art to make or use the invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the invention. Therefore, the invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A friction-type power take-off (PTO), comprising a housing (7), an output shaft (12) rotatably disposed within the housing (7), an output gear (10) rotatably disposed on the output shaft (12), a clutch (13) connected to the output gear (10), the clutch (13) being connected to the output shaft (12), and further comprising an input shaft (2), an input gear (18) disposed on the input shaft (2) via a bearing, the output gear (10) being rotatable under the drive of the input gear (18), characterized in that, A spline piston (22) is keyed to the outer circumference of the input shaft (2). The spline piston (22) can move along the input shaft (2) inside the input gear (18). The spline piston (22) can be keyed to the inner hole of the input gear (18). An elastic element (21) is provided between one end of the spline piston (22) and the corresponding bearing. An oil cavity (40) is formed between the other end of the spline piston (22) and the input end cover (4), the input shaft (2), and the input gear (18). An oil inlet hole (41) is also provided on the input end cover (4). The oil inlet hole (41) is connected to the oil cavity (40). The oil inlet hole (41) is connected to an oil source, which can provide hydraulic oil. The input gear (18) is provided with a pressure relief oil passage (181). One end of the pressure relief oil passage (181) is connected to the oil chamber (40) and the connection position is close to the spline piston (22). The other end of the pressure relief oil passage (181) is connected to the housing (7). The input shaft (2) is coaxially connected to the drive shaft (1). An external coupling blade (2001) is provided on the outer circumference of the input shaft (2). The external coupling blade (2001) is located in the oil cavity (40). An internal coupling blade (182) is provided in the inner hole of the input gear (18). The input end cap (4) is also provided with a fine oil outlet hole (42), which is connected to the oil cavity (40). The diameter of the fine oil outlet hole (42) is smaller than the diameter of the pressure relief oil passage (181).

2. The friction-type power take-off as described in claim 1, characterized in that, The outer cylindrical shaft of the spline piston (22) is provided with a fourth spline (223), and the inner hole of the input gear (18) is provided with a second spline (183). The fourth spline (223) and the second spline (183) can mesh. Both the fourth spline (223) and the second spline (183) are provided with chamfers.

3. The friction-type power take-off as described in claim 1, characterized in that, It also includes an intermediate shaft (6), on which an intermediate gear (9) is rotatably mounted. The intermediate gear (9) meshes with the input gear (18) and the output gear (10) respectively. Both ends of the intermediate shaft (6) are mounted on the housing (7).

4. The friction-type power take-off as described in claim 1, characterized in that, The spline piston (22) is provided with a third sealing ring (222) and a second sealing ring (221) from the outside to the inside at the end of the oil chamber (40).

5. The friction-type power take-off as described in claim 4, characterized in that, A first oil seal (3) is provided between the input end cover (4) and the input shaft (2), and a first sealing ring (43) is provided between the input end cover (4) and the input gear (18).

6. The friction-type power take-off as described in claim 1, characterized in that, The input gear (18) is provided with a first bearing (5) and a second bearing (17) at both ends, and both the first bearing (5) and the second bearing (17) are located inside the housing (7).

7. The friction-type power take-off as described in claim 6, characterized in that, A third bearing (24) and a fourth bearing (20) are provided between the input shaft (2) and the input gear (18). The third bearing (24) is located in the oil chamber (40). An elastic element (21) is provided between the fourth bearing (20) and the spline piston (22). The third bearing (24) and the fourth bearing (20) are both positioned on the input shaft (2) by snap rings.

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