A low oil level lubrication structure for a power take-off

Abstract

This invention discloses a low-oil-level lubrication structure for a power take-off (PTO), primarily relating to the technical field of mechanical transmission. It includes an input shaft and an output shaft rotatably mounted on a housing. The housing has a first bearing and a second bearing that mate with the input shaft. An intermediate shaft connects the input and output shafts. A first gear and a second gear are respectively mounted on the input and output shafts. A third gear meshes with both the first and second gears on the intermediate shaft. A third bearing connects the first gear to the input shaft. An oil ring is slidably connected to the input shaft. The oil ring has several grooves spirally extending from the outer to the inner ring. An intermediate oil cavity communicating with the grooves is located within the oil ring. The input shaft has an oil delivery channel that mates with the first, second, and third bearings, and this channel communicates with the intermediate oil cavity. The advantages of this invention are: solving the problems of heat generation at high oil levels and insufficient lubrication at low oil levels, and reducing energy loss during the rotation of the input shaft.

Description

Technical Field

[0001] This invention relates to the technical field of mechanical transmission, specifically a low-oil-level lubrication structure for a power take-off (PTO). Background Technology

[0002] The demand for specialized vehicles is constantly increasing. These vehicles commonly use power take-offs (PTOs) to extract power from the engine or transmission, enabling them to operate in specific applications. For conditions requiring high or full engine power output, vehicles are generally equipped with high-power PTOs such as single-shaft PTOs or sandwich PTOs. These PTOs typically output power from the transmission input shaft via gear transmission and use a splash lubrication method. This lubrication method requires a large amount of lubricating oil to maintain a high oil level, generally slightly higher than the bearings on both sides, to ensure sufficient lubrication in both engaged and disengaged gears. However, as the oil level increases, the churning losses from gear rotation also increase, leading to increased heat generation in the PTO. In severe cases, an additional cooling system is needed for heat dissipation. To address the issues of heat generation at high oil levels and insufficient lubrication at low oil levels, most vehicles employ active lubrication using mechanical oil pumps (rotary pumps, gear pumps, etc.). This method increases structural complexity and power loss. Summary of the Invention

[0003] The purpose of this invention is to provide a low-oil-level lubrication structure for a power take-off (PTO) to solve the problems of heat generation at high oil levels and insufficient lubrication at low oil levels, thereby reducing energy loss during the input shaft rotation process.

[0004] To achieve the above objectives, the invention employs the following technical solution:

[0005] A low-oil-level lubrication structure for a power take-off (PTO) includes an input shaft and an output shaft rotatably mounted on a housing. The housing has a first bearing and a second bearing that mate with the input shaft. An intermediate shaft is located between the input shaft and the output shaft. A first gear and a second gear are respectively mounted on the input shaft and the output shaft. A third gear is mounted on the intermediate shaft and meshes with both the first gear and the second gear. A third bearing is located between the first gear and the input shaft. An oil ring is slidably connected to the input shaft. The oil ring has several grooves spirally extending from the outer ring to the inner ring. An intermediate oil cavity communicating with the grooves is located within the oil ring. The input shaft has an oil delivery channel that mates with the first bearing, the second bearing, and the third bearing, and the oil delivery channel is connected to the intermediate oil cavity.

[0006] Furthermore, a spline sleeve is provided between the oil ring and the first gear, and a fifth gear that meshes with the spline sleeve is provided on the outer side of the input shaft. The spline sleeve is slidably connected to the input shaft. An outer conical ring is provided on the side of the first gear, and an inner conical ring that contacts the outer conical ring is provided on one side of the oil ring. A gear ring that meshes with the spline sleeve is provided on the outer conical ring.

[0007] Furthermore, a dial ring is slidably connected to the input shaft, and a torque transmission pin is provided on the dial ring. The torque transmission pin passes through the oil ring and is connected to the spline sleeve. A compression spring is sleeved on the outside of the torque transmission pin. The compression spring is located between the dial ring and the oil ring, and the spline sleeve is in contact with one side of the oil ring.

[0008] Furthermore, the dial ring is provided with a groove, and a dial fork is rotatably connected to the housing, with both sides of the dial fork contacting the groove respectively.

[0009] A shift fork shaft is rotatably connected to the housing, and the shift fork has a through hole for the shift fork shaft to pass through. A cylinder for driving the shift fork shaft to rotate is provided on the outside of the housing.

[0010] The end of the shift fork shaft is provided with a shift block, the movable end of the cylinder is provided with a push block, the push block is provided with a connecting shaft, and the shift block is provided with a slot that is slidably connected to the connecting shaft.

[0011] Furthermore, the oil supply channel includes a main oil passage provided on the input shaft. One end of the main oil passage is a blind hole, and the other end is provided with a block. The input shaft is provided with a first oil passage that communicates with the main oil passage and the intermediate oil chamber. The main oil passage is connected to a second oil passage, a third oil passage, and a fourth oil passage that cooperate with the first bearing, the second bearing, and the third bearing.

[0012] Furthermore, an O-ring is provided on the oil ring to fit the intermediate oil cavity between it and the input shaft.

[0013] Furthermore, a cover plate is rotatably connected to the inlet end of the groove, and a baffle connected to an oil ring is provided on one side of the cover plate. A torsion spring and a sealing strip are provided between the baffle plate and the cover plate.

[0014] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0015] 1. When the gear is disengaged, the input shaft drives the oil ring to rotate counterclockwise, which causes the spiral grooves in the oil ring to guide the oil into the middle oil cavity of the oil ring. The oil is then transported to the vicinity of the first bearing, the second bearing, and the third bearing through the oil delivery channel, respectively lubricating the first bearing, the second bearing, and the third bearing. This ensures that even without the agitation and splashing of the first gear, the lubrication of the three bearings can still be guaranteed when the gear is disengaged, reducing the friction of the input shaft rotating on the housing in the disengaged state and reducing the energy loss during the rotation of the input shaft.

[0016] 2. When shifting gears, as the input shaft rotation speed increases, the efficiency of the oil ring rotation will be accelerated, causing the oil to rotate rapidly from the outside to the inside in the groove, improving the oil supply efficiency of the oil ring to the oil delivery channel. When the input shaft rotation speed decreases, the oil supply efficiency of the oil ring to the oil delivery channel will decrease accordingly, so that the oil ring oil supply efficiency changes automatically, realizing automatic lubrication of the output shaft at different speeds. It is not necessary to maintain a high oil level for a long time, reducing the heat generated by the oil stirring of the first gear when shifting gears, thereby reducing the energy loss during the rotation of the input shaft.

[0017] 3. When disengaging, the spline sleeve is driven to slide through the cooperation between the cylinder, push block, connecting shaft, slot, shift fork, shift fork shaft, and through hole, so that it slides between the fifth gear and the gear ring. At the same time, there is no need to set up a separate drive device to drive several torque transmission pins to slide on the shift ring, reducing the space required for drive device installation and the manufacturing cost.

[0018] 4. By having the shift fork contact the left side of the groove, the transmission pin slides to the left on the shift ring, causing the spline sleeve to disengage from the fifth gear and the gear ring, and contact one side of the oil ring, causing the oil ring to slide to the left and compress the compression spring, thereby releasing the contact relationship between the inner and outer cone rings, so that the input shaft no longer drives the first gear to rotate, reducing the energy loss of the input shaft when disengaging.

[0019] 5. When gear shifting is required, the cylinder drives the torque transmission pin to slide to the right on the input shaft, causing the spline sleeve to slide to the right. Under the action of the spring return force, the oil ring slides to the right. Under the action of the friction between the inner and outer conical rings, the oil ring first drives the first gear to start rotating from rest until the speed of the first gear and the oil ring is close to or synchronized. This makes it easier to slide the spline sleeve back between the fifth gear and the gear ring. This avoids the spline sleeve rotating at high speed relative to the first gear when it slides between the gear ring and the fifth gear, which would cause a violent collision and damage to the spline sleeve and the first gear. When the spline sleeve is fully engaged with the fifth gear and the gear ring, the torque generated by the rotation of the input shaft will be transmitted to the first gear through the spline sleeve, thereby driving the output shaft to rotate.

[0020] 6. During normal operation, the oil in the intermediate oil chamber is introduced into the main oil passage through the first oil passage, and the oil flows to the first bearing, second bearing, and third bearing through the second, third, and fourth oil passages respectively. This ensures that even without the agitation and splashing of the first gear, the lubrication of the three bearings can still be guaranteed when the gear is disengaged. When the gear is engaged, the oil on the third bearing is splashed by the centrifugal force, thereby lubricating the intermediate shaft, the third gear, the second gear, and the output shaft respectively.

[0021] 7. When adding oil, rotate the cover plate counterclockwise to smoothly add oil into the groove. After adding oil, reset the cover plate through the torsion spring. When the input shaft stops rotating, the hydraulic oil backflow applies external force to the cover plate, preventing the cover plate from rotating clockwise through the baffle, thus preventing oil from flowing out of the cover plate. At the same time, the force of the oil acting on the cover plate further presses the sealing strip between the cover plate and the baffle, strengthening the sealing between the cover plate and the baffle. Attached Figure Description

[0022] Appendix Figure 1 This is a schematic diagram of the input and output shafts of the present invention.

[0023] Appendix Figure 2 This is a schematic diagram of the input shaft of the present invention.

[0024] Appendix Figure 3 This is a schematic diagram of the structure of the shift fork of the present invention.

[0025] Appendix Figure 4 This is a schematic diagram of the structure of the shift fork shaft of the present invention.

[0026] Appendix Figure 5 This is a schematic diagram of the structure of the oil ring of the present invention.

[0027] Appendix Figure 6 This is an appendix to the present invention. Figure 5 A magnified view of part A in the middle.

[0028] Appendix Figure 7 This is an isometric view of the spline sleeve of the present invention.

[0029] Appendix Figure 8 This is an isometric view of the first gear of the present invention.

[0030] Appendix Figure 9 This is an isometric view of the input shaft of the present invention.

[0031] The labels shown in the attached diagram:

[0032] 1. Housing; 2. Input shaft; 3. Output shaft; 4. First bearing; 5. Second bearing; 6. Intermediate shaft; 7. First gear; 8. Second gear; 9. Third gear; 10. Third bearing; 11. Oil ring; 12. Groove; 13. Intermediate oil cavity; 14. Spline sleeve; 15. Fifth gear; 16. Outer conical ring; 17. Inner conical ring; 18. Gear ring; 19. Shift ring; 20. Torque transmission pin; 21. 21. Compression spring; 22. Groove; 23. Shift fork; 24. Shift fork shaft; 25. Through hole; 26. Cylinder; 27. Shift block; 28. Push block; 29. ​​Connecting shaft; 30. Slot; 31. Main oil passage; 32. Block; 33. First oil passage; 34. Second oil passage; 35. Third oil passage; 36. Fourth oil passage; 37. O-ring; 38. Cover plate; 39. Baffle; 40. Torsion spring; 41. Sealing strip. Detailed Implementation

[0033] The present invention will be further illustrated below with reference to specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the invention. Furthermore, it should be understood that after reading the teachings of this invention, those skilled in the art can make various alterations or modifications to the invention, and these equivalent forms also fall within the scope defined in this application.

[0034] This invention provides a low-oil-level lubrication structure for a power take-off (PTO), such as... Figure 1 , Figure 2 , Figure 3 , Figure 4 , Figure 6 and Figure 7 As shown, the device includes an input shaft 2 and an output shaft 3 rotatably mounted on a housing 1. The housing 1 is equipped with a first bearing 4 and a second bearing 5 that mate with the input shaft 2. These bearings reduce friction, allowing the input shaft 2 to rotate more effectively within the housing 1 and minimizing energy loss during rotation. An intermediate shaft 6 connects the input shaft 2 and the output shaft 3. A first gear 7 and a second gear 8 are mounted on the input shaft 2 and the output shaft 3, respectively. A third gear 9, meshing with both the first gear 7 and the second gear 8, is mounted on the intermediate shaft 6, transmitting power from the input shaft 2 to the output shaft 3 for power output. By changing the gear ratios of the first gear 7 and the third gear 9, and the second gear 8 and the third gear 9, the power output of the input shaft 2 is altered. The transmission ratio with the output shaft 3; a third bearing 10 is provided between the first gear 7 and the input shaft 2 to reduce the friction of the first gear 7 on the input shaft 2, so that the input shaft 2 can rotate better and reduce the energy loss during the rotation of the input shaft 2; an oil ring 11 is slidably connected on the input shaft 2 to lubricate the first bearing 4, the second bearing 5, and the third bearing 10, reducing the energy loss during the rotation of the input shaft 2; the oil ring 11 has a number of grooves 12 spirally extending from the outer ring to the inner ring, and the oil ring 11 has an intermediate oil cavity 13 communicating with the grooves 12; the input shaft 2 has an oil supply channel that cooperates with the first bearing 4, the second bearing 5, and the third bearing 10, and the oil supply channel is connected to the intermediate oil cavity 13, such as Figure 4As shown, the input shaft 2 drives the oil ring 11 to rotate counterclockwise, causing the spiral groove 12 inside the oil ring 11 to guide the oil along the groove 12 into the middle oil cavity 13 of the oil ring 11. The oil is then transported to the vicinity of the first bearing 4, the second bearing 5, and the third bearing 10 through the oil delivery channel, respectively lubricating the first bearing 4, the second bearing 5, and the third bearing 10. This ensures that even without the agitation and splashing of the first gear 7, the lubrication of the three bearings can still be guaranteed when the gear is disengaged. This reduces the frictional force of the input shaft 2 rotating on the housing 1 when the gear is disengaged, and reduces the energy loss during the rotation of the input shaft 2. In addition, when the rotation speed of the input shaft 2 increases, the rotation efficiency of the oil ring 11 will be increased, causing the oil to rotate rapidly from the outside to the inside in the groove 12, improving the oil supply efficiency of the oil ring 11 to the oil delivery channel. When the rotation speed of the input shaft 2 decreases, the oil supply efficiency of the oil ring 11 to the oil delivery channel will decrease accordingly, so that the oil supply efficiency of the oil ring 11 changes automatically, realizing automatic lubrication of the output shaft 3 at different speeds.

[0035] Preferred, such as Figure 2 , Figure 3 and Figure 4 As shown, a spline sleeve 14 is provided between the oil ring 11 and the first gear 7. A fifth gear 15 is provided on the outer side of the input shaft 2, meshing with the spline sleeve 14, so that the input shaft 2 drives the spline sleeve 14 to rotate. The spline sleeve 14 is slidably connected to the input shaft 2, so that the spline sleeve 14 slides off the fifth gear 15, thereby releasing the connection between the first gear 7 and the input shaft 2. The side of the first gear 7 is provided with an outer conical ring 16, and one side of the oil ring 11 is provided with an inner conical ring 17 that contacts the outer conical ring 16. Under the action of friction between 6, the oil ring 11 first drives the first gear 7 to start rotating from rest until the speed of the first gear 7 and the oil ring 11 are close or synchronized. This makes it easier to slide the spline sleeve 14 back between the fifth gear 15 and the gear ring 18. This avoids the spline sleeve 14 from being violently impacted by high-speed rotation relative to the first gear 7 when it slides between the gear ring 18 and the fifth gear 15, which would cause damage to the spline sleeve 14 and the first gear 7. The outer conical ring 16 is provided with a gear ring 18 that meshes with the spline sleeve 14, so that the input shaft 2 drives the first gear 7 to rotate.

[0036] Preferred, such as Figure 2 , Figure 3 and Figure 4As shown, a dial ring 19 is slidably connected to the input shaft 2. A torque transmission pin 20 is provided on the dial ring 19. The torque transmission pin 20 passes through the oil ring 11 and connects to the spline sleeve 14. A compression spring 21 is sleeved on the outer side of the torque transmission pin 20. The compression spring 21 is positioned between the dial ring 19 and the oil ring 11. As the dial ring slides to the right on the input shaft, it drives the torque transmission pin 20 to slide to the right. Simultaneously, the oil ring 11 slides to the right under the rebound force of the compression spring 21, causing the inner conical ring 17 to contact the outer conical ring 16. This drives the first gear 7 to rotate from rest until the speed of the first gear 7 and the oil ring 11 approaches or synchronizes. At this point, the torque transmission pin 20 then drives the spline sleeve 14 to slide to the right until the spline sleeve 14... 4. The gear 14 slides between the fifth gear 15 and the gear ring 18, causing the input shaft 2 to drive the first gear 7 to rotate. This reduces the impact generated by the meshing of the spline sleeve 14 and the fifth gear 15. At the same time, it eliminates the need to separately control the oil ring 11 and the spline sleeve 14 to slide on the input shaft 2, reducing the number of steps required for the input shaft 2 to drive the first gear 7 to rotate. The spline sleeve 14 contacts one side of the oil ring 11 and drives the oil ring 11 to slide on the input shaft 2. When the gear is disengaged, the transmission pin 20 drives the spline sleeve 14 to reset. The spline sleeve 14 contacts one side of the oil ring 11 and drives the oil ring 11 to slide on the input shaft 2, releasing the contact relationship between the inner cone ring 17 and the outer cone ring 16, causing the first gear 7 to stop rotating and reducing the energy loss of the input shaft 2 when the gear is disengaged.

[0037] Preferred, such as Figure 2 , Figure 3 and Figure 4 As shown, the dial ring 19 is provided with a groove 22, and the housing 1 is rotatably connected with a dial fork 23. The two sides of the dial fork 23 are in contact with the groove 22 respectively. The dial fork 23 rotates on the housing 1 and makes the dial fork 23 contact one side of the groove 22, thereby driving the transmission pin 20 to slide on the dial ring 19.

[0038] Preferred, such as Figure 3 and Figure 4 As shown, a shift fork shaft 24 is rotatably connected to the housing 1. The shift fork 23 is provided with a through hole 25 for the shift fork shaft 24 to pass through. A cylinder 26 is provided on the outside of the housing to drive the shift fork shaft 24 to rotate. By driving the shift fork shaft 24 to rotate on the housing 1 by the cylinder 26, the shift fork 23 contacts one side of the groove, thereby driving the spline sleeve 14 to slide and slide between the fifth gear 15 and the gear ring 18. At the same time, the cylinder 26 is located on the outside of the housing 1, which facilitates the subsequent maintenance of the cylinder 26.

[0039] Preferred, such as Figure 3 and Figure 4As shown, the end of the shift fork shaft 24 is provided with a shift block 27, the movable end of the cylinder 26 is provided with a push block 28, the push block 28 is provided with a connecting shaft 29, and the shift block 26 is provided with a slot 30 that is slidably connected to the connecting shaft 29. The cylinder 26 drives the push block to slide up and down. Since the side of the connecting shaft 29 is in contact with both sides of the slot 30, it drives one end of the shift block 27 to swing up and down, so that the shift fork shaft 24 rotates on the housing 1, thereby driving the spline sleeve 14 to slide.

[0040] Preferred, such as Figure 2 and Figure 9 As shown, the oil supply channel includes a main oil passage 31 disposed on the input shaft 2. One end of the main oil passage 31 is a blind hole, and the other end is provided with a plug 32. During maintenance, the oil can be drained by removing the plug 32. The input shaft 2 is provided with a first oil passage 33 that communicates with the main oil passage 31 and the intermediate oil chamber 13. The main oil passage 31 is connected to a second oil passage 34, a third oil passage 35, and a fourth oil passage 36 that cooperate with the first bearing 4, the second bearing 5, and the third bearing 10. 33 introduces the oil from the intermediate oil chamber 13 into the main oil passage 31, and then flows the oil to the first bearing 4, the second bearing 5, and the third bearing 10 through the second oil passage 34, the third oil passage 35, and the fourth oil passage 36, respectively. This ensures that even without the agitation and splashing of the first gear 7, the lubrication of the three bearings can still be guaranteed when the gear is disengaged. When the gear is engaged, the oil on the third bearing 10 is splashed by the centrifugal force, thereby lubricating the intermediate shaft 6, the third gear 9, the second gear 8, and the output shaft 3, respectively.

[0041] Preferred, such as Figure 2 As shown, an O-ring 37 is provided on the oil ring 11 and between it and the input shaft 2 to fit the intermediate oil cavity 13, so as to prevent oil from flowing out from the gap between the oil ring 11 and the input shaft 2.

[0042] Preferably, a cover plate 38 is rotatably connected to the inlet end of the groove 12, so that when oil is introduced, such as... Figure 6 As shown, rotating the cover plate 38 counterclockwise smoothly adds oil into the groove 12. One side of the cover plate 38 is provided with a baffle 39 connected to the oil ring 11. When the input shaft 2 stops rotating, it prevents the oil from flowing back and out of the cover plate 38. At the same time, the force of the oil acting on the cover plate 38 further presses the sealing strip 41 between the cover plate 38 and the baffle 39, strengthening the sealing between the cover plate 38 and the baffle 39. A torsion spring 40 and a sealing strip 41 are provided between the baffle 39 and the cover plate 38. The cover plate 38 is reset by the torsion spring 40.

[0043] Example 1

[0044] This invention provides a low-oil-level lubrication structure for a power take-off (PTO), such as... Figure 1 , Figure 2 , Figure 5 , Figure 7 and Figure 8 As shown, the device includes an input shaft 2 and an output shaft 3 rotatably mounted on a housing 1. The housing 1 is provided with a first bearing 4 and a second bearing 5 that cooperate with the input shaft 2 to reduce the friction between the first bearing 4 and the second bearing 5, allowing the input shaft 2 to rotate better on the housing 1 and reducing energy loss during the rotation of the input shaft 2. An intermediate shaft 6 is provided between the input shaft 2 and the output shaft 3. The input shaft 2 and the output shaft 3 are respectively provided with a first gear 7 and a second gear 8. The intermediate shaft 6 is provided with a third gear 9 that meshes with the first gear 7 and the second gear 8, respectively, to transmit power from the input shaft 2 to the output shaft 3 for power output. By changing the gear ratio between the first gear 7 and the third gear 9, and between the second gear 8 and the third gear 9, the transmission ratio between the input shaft 2 and the output shaft 3 is changed.

[0045] like Figure 4 As shown, when the gear is disengaged, the input shaft 2 drives the oil ring 11 to rotate counterclockwise, causing the spiral groove 12 inside the oil ring 11 to guide the oil along the groove 12 into the middle oil cavity 13 of the oil ring 11. The oil is then transported through the oil delivery channel to the vicinity of the first bearing 4, the second bearing 5, and the third bearing 10, respectively, to lubricate these bearings. This ensures that even without the agitation and splashing of the first gear 7, lubrication of the three bearings is maintained when the gear is disengaged, reducing the frictional force of the input shaft 2 rotating on the housing 1 in the disengaged state and minimizing the excessive rotation of the input shaft 2. The energy loss during the process is reduced; in addition, when the rotation speed of the input shaft 2 increases, the rotation efficiency of the oil ring 11 will be accelerated, so that the oil will rotate rapidly from the outside to the inside in the groove 12, improving the oil supply efficiency of the oil ring 11 to the oil delivery channel. When the rotation speed of the input shaft 2 decreases, the oil supply efficiency of the oil ring 11 to the oil delivery channel will decrease accordingly, so that the oil supply efficiency of the oil ring 11 will change automatically, realizing automatic lubrication of the output shaft 3 at different speeds. It is not necessary to maintain a high oil level for a long time, reducing the heat generated by the oil stirring of the first gear 7 when shifting gears, thereby reducing the energy loss during the rotation process of the input shaft 2.

[0046] Example 2

[0047] Based on Example 1, such as Figure 2 , Figure 3 and Figure 4As shown, when disengaging from gear, the cylinder 26 drives the push block to slide upward, causing the side of the connecting shaft 29 to contact the upper side of the slot 30. This causes one end of the shift block 27 to swing upward, driving the shift fork shaft 24 to rotate clockwise on the housing 1. This causes the shift fork 23 to contact the left side of the groove 22, causing the shift ring 19 to slide to the left on the input shaft 2. This, in turn, causes the torque transmission pin 20 to slide to the left, disengaging the spline sleeve 14 from the fifth gear 15 and the gear ring 18, and contacting one side of the oil ring 11. This causes the oil ring 11 to slide to the left and compress the compression spring 21, thereby releasing the contact between the inner cone ring 17 and the outer cone ring 16. This prevents the input shaft 2 from driving the first gear 7 to rotate, reducing the energy loss of the input shaft 2 when disengaging from gear. At this time, the spline sleeve 14 is still engaged with the gear ring 18, causing the input shaft to drive the spline sleeve 14 to rotate. Since the transmission pin 20 passes through the oil ring 11 and then connects with the spline sleeve 14, it drives the oil ring 11 to rotate counterclockwise. This causes the spiral groove 12 in the oil ring 11 to guide the oil along the groove 12 into the middle oil cavity 13 of the oil ring 11, and then deliver the oil to the vicinity of the first bearing 4, the second bearing 5, and the third bearing 10, respectively lubricating the first bearing 4, the second bearing 5, and the third bearing 10. This ensures that even without the agitation and splashing of the first gear 7, the lubrication of the three bearings can still be guaranteed in the disengaged state, reducing the friction of the input shaft 2 rotating on the housing 1 in the disengaged state and reducing the energy loss during the rotation of the input shaft 2.

[0048] When gear shifting is required, the cylinder 26 drives the torque transmission pin 20 to slide to the right on the input shaft 2, causing the spline sleeve 14 to slide to the right. Under the action of the spring 21, the oil ring 11 slides to the right. Under the action of the friction between the inner conical ring 17 and the outer conical ring 16, the oil ring 11 first drives the first gear 7 to start rotating from rest until the speed of the first gear 7 and the oil ring 11 are close or synchronized. This makes it easier to slide the spline sleeve 14 back into the space between the fifth gear 15 and the gear ring 18. This avoids the spline sleeve 14 from rotating at high speed relative to the first gear 7 when it slides into the space between the gear ring 18 and the fifth gear 15, causing a violent collision that could damage the spline sleeve 14 and the first gear 7. When the spline sleeve 14 is fully engaged with the fifth gear 15 and the gear ring 18, the torque generated by the rotation of the input shaft 2 will be transmitted to the first gear 7 through the spline sleeve 14, thereby driving the output shaft 3 to rotate.

[0049] Example 3

[0050] Based on Example 1, such as Figure 2 and Figure 9As shown, the oil supply channel includes a main oil passage 31 set on the input shaft 2. One end of the main oil passage 31 is a blind hole, and the other end is provided with a block 32. During maintenance, the oil can be drained by opening the block 32. During normal operation, the oil in the intermediate oil chamber 13 is introduced into the main oil passage 31 through the first oil passage 33, and the oil flows to the first bearing 4, the second bearing 5, and the third bearing 10 through the second oil passage 34, the third oil passage 35, and the fourth oil passage 36, respectively. This ensures that even without the agitation and splashing of the first gear 7, the lubrication of the three bearings can still be guaranteed when the gear is disengaged. When the gear is engaged, the oil on the third bearing 10 is splashed under the action of centrifugal force, which lubricates the intermediate shaft 6, the third gear 9, the second gear 8, and the output shaft 3, respectively. In addition, an O-ring 37 is provided between the oil ring 11 and the input shaft 2 to prevent the oil from flowing out from the gap between the oil ring 11 and the input shaft 2.

[0051] Example 4

[0052] Based on Example 1, such as Figure 5 and Figure 6 As shown, when oil is being added, the cover plate 38 is rotated counterclockwise to smoothly add oil into the groove 12. After the oil is added, the cover plate 38 is reset by the torsion spring 40. When the input shaft 2 stops rotating, the baffle 39 prevents the cover plate 38 from rotating clockwise, thus preventing the oil from flowing back and out of the cover plate 38. At the same time, the force of the oil acting on the cover plate 38 further presses the sealing strip 41 between the cover plate 38 and the baffle 39, thereby strengthening the sealing between the cover plate 38 and the baffle 39.

Claims

1. A low-oil-level lubrication structure for a power take-off (PTO) includes an input shaft (2) and an output shaft (3) rotatably mounted on a housing (1). The housing (1) is provided with a first bearing (4) and a second bearing (5) that mate with the input shaft (2). An intermediate shaft (6) is provided between the input shaft (2) and the output shaft (3). A first gear (7) and a second gear (8) are respectively provided on the input shaft (2) and the output shaft (3). A third gear (5) is provided on the intermediate shaft (6) that meshes with the first gear (7) and the second gear (8). 9) A third bearing (10) is provided between the first gear (7) and the input shaft (2). An oil ring (11) is slidably connected on the input shaft (2). The oil ring (11) is provided with a number of grooves (12) that spirally extend from the outer ring to the inner ring. An intermediate oil cavity (13) is provided in the oil ring (11) that communicates with the grooves (12). The input shaft (2) is provided with an oil supply channel that cooperates with the first bearing (4), the second bearing (5), and the third bearing (10). The oil supply channel is connected to the intermediate oil cavity (13).

2. The low oil level lubrication structure for a power take-off unit according to claim 1, characterized in that: A spline sleeve (14) is provided between the oil ring (11) and the first gear (7). A fifth gear (15) that meshes with the spline sleeve (14) is provided on the outside of the input shaft (2). The spline sleeve (14) is slidably connected to the input shaft (2). The side of the first gear (7) is provided with an outer conical ring (16). One side of the oil ring (11) is provided with an inner conical ring (17) that contacts the outer conical ring (16). A gear ring (18) that meshes with the spline sleeve (14) is provided on the outer conical ring (16).

3. The low oil level lubrication structure for a power take-off unit according to claim 2, characterized in that: A dial ring (19) is slidably connected to the input shaft (2). A torque transmission pin (20) is provided on the dial ring (19). The torque transmission pin (20) passes through the oil ring (11) and is connected to the spline sleeve (14). A compression spring (21) is sleeved on the outside of the torque transmission pin (20). The compression spring (21) is located between the dial ring (19) and the oil ring (11). The spline sleeve (14) is in contact with one side of the oil ring (11).

4. The low oil level lubrication structure for a power take-off unit according to claim 3, characterized in that: The dial ring (19) is provided with a groove (22), and the housing (1) is rotatably connected with a fork (23), and the two sides of the fork (23) are in contact with the groove (22) respectively.

5. A low-oil-level lubrication structure for a power take-off unit according to claim 4, characterized in that: The housing (1) is rotatably connected to a shift fork shaft (24), the shift fork (23) is provided with a through hole (25) for the shift fork shaft (24) to pass through, and the outer side of the housing is provided with a cylinder (25) for driving the shift fork shaft (24) to rotate.

6. The low oil level lubrication structure for a power take-off unit according to claim 5, characterized in that: The end of the shift fork shaft (24) is provided with a shift block (26), the movable end of the cylinder (25) is provided with a push block (27), the end of the push block is provided with a first groove (28) for the shift block to slide, the push block (27) is provided with a connecting shaft (29), and the shift block (26) is provided with a second groove (30) that is slidably connected to the connecting shaft (29).

7. A low-oil-level lubrication structure for a power take-off unit according to claim 1, characterized in that: The oil supply channel includes a main oil passage (31) set on the input shaft (2). One end of the main oil passage (31) is a blind hole, and the other end is provided with a block (32). The input shaft (2) is provided with a first oil passage (33) that communicates with the main oil passage (31) and the intermediate oil chamber (13). The main oil passage (31) is connected to a second oil passage (34), a third oil passage (35), and a fourth oil passage (36) that cooperate with the first bearing (4), the second bearing (5), and the third bearing (10).

8. The low oil level lubrication structure for a power take-off unit according to claim 1, characterized in that: An O-ring (37) is provided on the oil ring (11) and between it and the input shaft (2) to fit the intermediate oil cavity (13).

9. A low-oil-level lubrication structure for a power take-off unit according to claim 1, characterized in that: The groove (12) is rotatably connected to a cover plate (38). A baffle (39) connected to an oil ring (11) is provided on one side of the cover plate (38). A torsion spring (40) and a sealing strip (41) are provided between the baffle (39) and the cover plate (38).

Images