Power transmission assembly in rear axle of tractor

Abstract

The power transmission assembly comprises a gearbox shell and a first power input shaft, a wheel driving mechanism is arranged on the surface of the first power input shaft, the end of the first power input shaft is in transmission connection with a first driving gear, and a first power output shaft is arranged in the first driving gear; a first clutch gear is arranged on the surface of one end of the first power output shaft, the first power output shaft rotates along with rotation of the first clutch gear, a second power output shaft is arranged on the surface of the other end of the first power output shaft, a variable-speed transmission gear is arranged on the surface of the wheel driving mechanism, and a speed change mechanism is arranged on the surface of the second power output shaft. A second clutch gear is arranged on the surface of the second power output shaft; through the layout design, the left side of the first driving gear can serve as the driving force of the first clutch gear, and the right side of the first driving gear can serve as the driving force of the second clutch gear. The transmission efficiency is improved due to the integration of the whole structure.

Description

Technical Field

[0001] The present invention relates to the technical field of tractor transmissions, and particularly to a power transmission assembly inside the rear axle of a tractor. Background Art

[0002] Two-wheel tractors are a type of multi-functional mechanical equipment widely used in agricultural production, known for their flexible operation and powerful power output. The power take-off shaft of this type of tractor can be adapted to various agricultural accessories such as snow plows, snow shovels, and cultivators, with high practicality and versatility. In winter, when snow plowing and snow shoveling accessories are installed on the two-wheel tractor, it can quickly clear the snow on farmland and surrounding roads, clearing the way for spring farming. And during the farming season, the two-wheel tractor with a cultivator accessory can shuttle through the fields, efficiently completing tasks such as soil tillage and weed removal, creating good soil conditions for the growth of crops. With its excellent versatility and efficiency, the two-wheel tractor has greatly improved agricultural production efficiency and reduced the labor intensity of farmers, becoming an indispensable important tool in modern agricultural production.

[0003] The authorized announcement number is CN212950129U, which discloses a tractor rear axle structure. Combining its specification and drawings, both the bevel gear shaft of the rear axle and the front end of the rear axle input shaft can be connected to a universal drive shaft to achieve articulated steering. By arranging the bevel gear shaft of the rear axle and the rear axle input shaft up and down and combining with a reverse idler gear, 8 forward gears and 2 reverse gears are realized.

[0004] However, its solution still has the following defects: 1. How to ensure precise control of the tractor to adapt the rotation of the power take-off shaft of agricultural accessories while realizing the functions of forward and backward is one of the problems that need to be considered; 2. How to realize automatic gear shifting of the agricultural machine to drive agricultural accessories during the forward movement of the tractor is also one of the problems that need to be considered; 3. How to design the relationship between the variable-speed power transmission and the power take-off shaft with high integration is also one of the problems that need to be considered. Summary of the Invention

[0005] The present invention mainly aims at the problems existing in the internal power transmission structure of the tractor rear axle, and invents a power transmission assembly inside the tractor rear axle. Through layout design, the left side of the first driving gear can be used as the driving force of the first clutch gear, and the right side of the first driving gear can also be used as the driving force of the second clutch gear; when the second clutch gear is in the forward gear position, the first power output shaft can rotate automatically.

[0006] The object of the present invention is achieved by the following technical solutions: A power transmission assembly inside the rear axle of a tractor, a gearbox housing, a first power input shaft disposed inside the gearbox housing, a wheel drive mechanism rotatably provided on the surface of the first power input shaft, a first drive gear drivingly connected to the end of the first power input shaft, a first power output shaft rotatably provided inside the first drive gear, a first clutch gear axially slidably provided on one end surface of the first power output shaft, the first power output shaft rotating with the rotation of the first clutch gear, the axial displacement of the first clutch gear enabling engagement or separation with the first drive gear, the end of the first power output shaft near the outside of the gearbox housing being drivingly connectable to the inside of agricultural accessories, a second power output shaft rotatably provided on the surface of the other end of the first power output shaft, a variable-speed transmission gear axially slidably provided on the surface of the wheel drive mechanism, the wheel drive mechanism rotating with the rotation of the variable-speed transmission gear, a plurality of variable-speed mechanisms drivingly connected to the variable-speed transmission gear provided on the surface of the second power output shaft, and a second clutch gear axially slidably provided on the surface of the second power output shaft, the axial displacement of the second clutch gear enabling engagement or separation with the first drive gear.

[0007] Preferably, a first clamping assembly and a second clamping assembly are provided inside the first power output shaft. After the axial displacement of the first clutch gear, the first clamping assembly can clamp the position of the first clutch gear relative to the first drive gear. After the second clutch gear meshes with the inside of the first drive gear, it can drive the second clamping assembly so that the first drive gear and the first power output shaft rotate simultaneously.

[0008] Preferably, the inside of the first clutch gear is splined to the surface of the first power output shaft. The surface of the first clutch gear is provided with first teeth and a first annular transmission groove. The inside of the first drive gear is provided with a tooth groove adapted to the first teeth. A first push block is provided inside the first annular transmission groove. The end of the first push block is hingedly connected to an external first rocker arm. The first push block can push the first clutch gear to engage or separate from the inside of the first drive gear.

[0009] Preferably, the first clamping component includes a first limiting spring and a first limiting steel ball. A first limiting through hole is provided inside the first power output shaft. The center line of the first limiting through hole is perpendicular to the axis of the first power output shaft. A first limiting spring is provided inside the first limiting through hole. First limiting steel balls are provided at both ends of the first limiting spring. A number of first limiting annular grooves are provided inside the first clutch gear. A number of first steel ball limiting plates are provided at the top of at least one of the first limiting annular grooves. The first limiting steel ball can slide relative to the first limiting annular groove, and the first limiting steel ball can be caught by the gap between adjacent first steel ball limiting plates.

[0010] Preferably, the inside of the second clutch gear is splined to the surface of the second power output shaft. A spline tooth adapted to the inside of the second clutch gear is provided on one side of the first driving gear. Second teeth are provided on the surface of the second clutch gear. A reverse gear is rotatably provided inside the gearbox housing. The first power input shaft is always meshed with the reverse gear. The sliding of the second clutch gear can be meshed with or separated from the first driving gear and the reverse gear.

[0011] Preferably, the second clamping component includes a first bearing, a second limiting spring and a second limiting steel ball. The hydraulic cavity between the surface of the first power output shaft and the inside of the first driving gear is sealed by the first bearing. A first oil passage is further provided inside the first power output shaft. A second limiting through hole is provided on the surface of the first power output shaft. A second limiting spring is provided inside the second limiting through hole. Second limiting steel balls are connected to both ends of the second limiting spring. A first pressure relief oil passage is further provided inside the first oil passage. A second pressure relief oil passage and a third pressure relief oil passage are provided inside the first driving gear. The center lines of the second pressure relief oil passage and the third pressure relief oil passage are perpendicular to each other. A third limiting spring is provided inside the third pressure relief oil passage. A third limiting steel ball is provided at the end of the third limiting spring. The position change of the third limiting steel ball can block the third pressure relief oil passage.

[0012] Preferably, a sealing film and a steel ball boss are provided on the surface of the third limiting steel ball close to the first driving gear. An annular boss capable of fitting to the steel ball boss is provided on the side of the second clutch gear. A pressure relief diversion hole is provided inside the third limiting steel ball. The inner diameter of the pressure relief diversion hole is smaller than the inner diameter of the second pressure relief oil passage. The top of the pressure relief diversion hole communicates with the second pressure relief oil passage and the side of the pressure relief diversion hole communicates with the inside of the third pressure relief oil passage. A second limiting annular groove is further provided inside the first driving gear. A number of second steel ball limiting plates are provided at the top of the second limiting annular groove. The second limiting steel ball can be caught by the gap between adjacent second steel ball limiting plates.

[0013] Preferably, the wheel driving mechanism includes a first worm, a first worm gear and a first bevel gear. The surface of the first power output shaft is rotatably provided with the first worm. The internal spline of the variable speed transmission gear is connected to the surface of the first worm. The end of the first worm is drivingly connected to the first worm gear. The inside of the first worm gear is drivingly connected with a number of first bevel gears. The inside of at least two first bevel gears is drivingly connected with a wheel drive shaft. This setting is to enable the wheel driving mechanism to drive the entire two-wheel tractor to move under the rotation of the variable speed transmission gear.

[0014] Preferably, the speed change mechanism includes a first speed change gear, a second speed change gear and a third speed change gear. The first speed change gear, the second speed change gear and the third speed change gear are all fixedly connected to the surface of the second power output shaft. The surface of the first worm is provided with a worm driving gear. The worm driving gear is always in a meshing state with the third speed change gear. The sliding of the variable speed transmission gear can be meshed with or separated from the first speed change gear and the second speed change gear. The sliding of the variable speed transmission gear can also be stuck or separated from the inside of the worm driving gear.

[0015] Preferably, the surface of the variable speed transmission gear is provided with a second annular transmission groove, a first transmission tooth and a second transmission tooth. The side of the variable speed transmission gear is provided with a variable speed transmission boss. The first transmission tooth is adapted to the first speed change gear. The second transmission tooth is adapted to the second speed change gear. The variable speed transmission boss can be stuck inside the worm driving gear. This setting is to enable the first clutch gear to be adapted to the speed change gears of the speed change mechanism.

[0016] Compared with the prior art, the present invention has the following beneficial effects: 1. The end of the first power output shaft is used as the power source for the agricultural machine accessories, and the second power output shaft is used as the power source for the forward and backward movement of the entire two-wheel tractor. The first power output shaft is rotatably designed in the middle of the first driving gear, and then the second power output shaft is rotatably designed inside the right side of the first power output shaft. The first clutch gear and the second clutch gear respectively control the rotation of the first power output shaft and the second power output shaft. Through the ingenious layout design, the left side of the first driving gear can be used as the driving force of the first clutch gear, and the right side of the first driving gear can also be used as the driving force of the second clutch gear. The entire structure is highly integrated, making the most of the power source and improving the transmission efficiency.

[0017] 2. When the second clutch gear is in the forward gear position, the inside of the second clutch gear meshes with the first drive gear. The annular boss will push the entire third limit ball through the ball boss to slide leftward against the elastic force of the third limit spring 524. The pressure relief diversion hole and the bottom of the second pressure relief oil path are no longer in a conducting state, and the largest middle area of the diameter of the third limit ball will block the hydraulic oil from flowing out to the outlet of the third pressure relief oil path. The hydraulic oil flowing down from the second pressure relief oil path will be retained in the area between the right side of the third limit ball and the sealing film, but it cannot flow out to the outside either. The entire oil path is in a pressure holding state inside, and each second limit ball will be stuck in the gap between the adjacent second ball limit plates. Through this design method, when in the forward gear position, the first power output shaft can rotate automatically, improving the automation degree during tractor operation.

[0018] 3. The rotation of the second power output shaft changes with the position change of the left and right sliding of the second clutch gear. During the rotation of the second power output shaft, the first speed change gear, the second speed change gear, and the third speed change gear all rotate simultaneously. The speed change transmission gear combined with different speed change gears can bring different speeds. The entire speed change structure is highly integrated, resulting in lower production and manufacturing costs for the enterprise.

[0019] 4. By designing two first limit annular grooves, two states of meshing or separation between the first clutch gear and the first power output shaft are achieved. After the axial displacement of the first clutch gear, the first clamping assembly can hold the position of the first clutch gear relative to the first drive gear. This holding is not a complete locking, but a preliminary limit on the sliding position of the first clutch gear. Users can not only use the maximum sliding range of the first clutch gear to judge the engagement state, but also use the first rocker arm to sense the torque change of the first limit ball, so as to judge whether the first clutch gear is stuck in the engaged gear position or the separated gear position, which is more convenient for users during use and optimizes the human-machine interaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 is a perspective view of the present invention; Figure 2 is a cross-sectional view of the present invention; Figure 3 is a partial cross-sectional view of the present invention; Figure 4 is a perspective view of the present invention after removing the transmission housing; Figure 5 is a partial perspective view of the present invention after removing the transmission housing; Figure 6 is a perspective view of the present invention after removing the first clutch gear from the surface of the first power output shaft; Figure 7Cross-sectional view of the first clamping component in the present invention; Figure 8 In the present invention Figure 2 Partial enlarged view of area A; Figure 9 In the present invention Figure 2 Partial enlarged view of area B; Figure 10 Cross-sectional view of the first driving gear in the present invention.

[0021] Markings in the figure: 1. Transmission housing; 11. Reverse gear; 2. First power input shaft; 3. Wheel drive mechanism; 31. First worm; 32. First worm wheel; 33. First bevel gear; 34. Worm drive gear; 35. Wheel drive shaft; 4. First driving gear; 41. Spline teeth; 42. Second pressure relief oil passage; 43. Third pressure relief oil passage; 44. Second limiting annular groove; 45. Second steel ball limiting plate; 5. First power output shaft; 51. First clamping component; 52. Second clamping component; 511. First limiting spring; 512. First limiting steel ball; 513. First limiting through hole; 521. First bearing; 522. Second limiting spring; 523. Second limiting steel ball; 524. Third limiting spring; 525. Third limiting steel ball; 526. Sealing film; 527. Steel ball boss; 528. Pressure relief diversion hole; 529. Hydraulic cavity; 6. First clutch gear; 61. First set of teeth; 62. First annular transmission groove; 63. First push block; 64. First limiting annular groove; 65. First steel ball limiting plate; 66. First rocker arm; 7. Transmission gear; 71. Second annular transmission groove; 72. First transmission tooth; 73. Second transmission tooth; 74. Transmission boss; 8. Transmission mechanism; 81. First transmission gear; 82. Second transmission gear; 83. Third transmission gear; 9. Second clutch gear; 91. Second set of teeth; 92. Annular boss; 10. Second power output shaft. Detailed implementation mode

[0022] The present invention will be further described below in conjunction with the embodiments shown in the drawings: As Figure 1 , Figure 2 and Figure 3 shown, a power transmission assembly inside the rear axle of a tractor includes a transmission housing 1, and a first power input shaft 2 arranged inside the transmission housing 1. The left end of the first power input shaft 2 is drivingly connected to a first driving gear 4. A first power output shaft 5 is rotatably arranged inside the first driving gear 4.

[0023] During the rotation of the first power input shaft 2, the first driving gear 4 rotates simultaneously. During the rotation of the first driving gear 4, it cannot directly drive the first power output shaft 5 to rotate.

[0024] One end surface of the first power output shaft 5 is provided with a first clutch gear 6 that can axially slide. The first power output shaft 5 rotates as the first clutch gear 6 rotates, and the axial displacement of the first clutch gear 6 can achieve engagement or separation from the first driving gear 4. The end of the first power output shaft 5 close to the outside of the transmission housing 1 can be drivingly connected to the inside of the agricultural accessories.

[0025] In Figure 3 , the first clutch gear 6 and the first driving gear 4 are in a separated state, and the first driving gear 4 cannot drive the first clutch gear 6 to rotate simultaneously when it rotates. When the first clutch gear 6 slides to the right until it engages with the inside of the first driving gear 4, the first driving gear 4 can drive the first clutch gear 6 during the rotation process. Then the first clutch gear 6 can drive the first power output shaft 5 to rotate simultaneously. At this time, the transmission of the external agricultural accessories is connected to the end of the first power output shaft 5.

[0026] In this embodiment, please continue to refer to Figure 6 and Figure 10 : In Figure 6 , the first clutch gear 6 is removed from the surface of the first power output shaft 5. The inside of the first clutch gear 6 can be splined to the surface of the first power output shaft 5. The surface of the first clutch gear 6 is provided with first teeth 61 and a first annular transmission groove 62, and the inside of the first driving gear 4 is provided with a tooth groove adapted to the first teeth 61. In this way, when the first clutch gear 6 slides to the right until it reaches the inside of the first driving gear 4, the first teeth 61 can engage with the internal tooth groove of the first driving gear 4, realizing the transmission between the first driving gear 4 and the first clutch gear 6.

[0027] As Figure 4 shown, a first push block 63 is arranged inside the first annular transmission groove 62. The end of the first push block 63 is hingedly connected to an external first rocker arm 66. The first push block 63 can push the first clutch gear 6 to engage with or separate from the inside of the first driving gear 4.

[0028] The user rotates the bottom of the first rocker arm 66 to change the position of the end of the first rocker arm 66. However, the hinged relationship between the end of the first rocker arm 66 and the end of the first push block 63 ensures that the first push block 63 is always stuck inside the first annular transmission groove 62. The first rocker arm 66 can drive the first push block 63 to push the entire first clutch gear 6 to slide on the left surface of the first power output shaft 5 during the rotation process.

[0029] Please refer to Figure 6 and Figure 7 , Figure 7The first clutch gear 6 and the first driving gear 4 are in a separated state. After the first clutch gear 6 slides and separates from the inside of the first driving gear 4, it is necessary to limit the relative position of the first clutch gear 6. The first power output shaft 5 is internally provided with a first clamping component 51. After the axial displacement of the first clutch gear 6, the first clamping component 51 can clamp the position of the first clutch gear 6 relative to the first driving gear 4. However, this clamping is not a firm locking, but a preliminary limit on the sliding position of the first clutch gear 6.

[0030] The first clamping component 51 includes a first limiting spring 511 and a first limiting steel ball 512. The first power output shaft 5 is internally provided with a first limiting through hole 513. The center line of the first limiting through hole 513 is perpendicular to the axis of the first power output shaft 5. The first limiting through hole 513 is internally provided with the first limiting spring 511. The two ends of the first limiting spring 511 are provided with the first limiting steel balls 512. The inside of the first clutch gear 6 is provided with a plurality of first limiting annular grooves 64. At least one of the tops of the first limiting annular grooves 64 is provided with a plurality of first steel ball limiting plates 65. The first limiting steel ball 512 can slide relative to the first limiting annular groove 64, and the first limiting steel ball 512 can be caught by the gap between adjacent first steel ball limiting plates 65.

[0031] The two first limiting annular grooves 64 respectively represent two states of the first clutch gear 6 being in engagement or separation with the first power output shaft 5. After the first limiting steel ball 512 is caught inside the first limiting annular groove 64, the elastic force generated by the first limiting spring 511 makes the first limiting steel ball 512 fit inside the first limiting annular groove 64. At this time, the position of the first clutch gear 6 relative to the first driving gear 4 is in a preliminary locked state. When the first push block 63 pushes the first clutch gear 6 to slide again, the tooth grooves inside the first clutch gear 6 will squeeze the first limiting steel ball 512 to move into the first limiting through hole 513. This process will continuously squeeze the first limiting spring 511 to deform, thereby increasing the friction between the first limiting steel ball 512 and the inside of the first clutch gear 6. The user uses the first rocker arm 66 to sense the change in the friction force of the first limiting steel ball 512, so as to judge whether the first clutch gear 6 is stuck in the engaged gear or the separated gear.

[0032] It should be noted that when the first clutch gear 6 is in an engaged state with the inside of the first driving gear 4. The first limiting steel ball 512 will also be caught by the gap between adjacent first steel ball limiting plates 65. The entire first clutch gear 6 cannot rotate relative to the first driving gear 4, and the cooperation degree between the first clutch gear 6 and the first driving gear 4 is higher, and the torque is greater.

[0033] When the first clutch gear 6 is in a separated state from the inside of the first drive gear 4, the entire first clutch gear 6 can rotate relative to the first drive gear 4.

[0034] In this embodiment, please refer to Figure 3 , Figure 5 , Figure 6 and Figure 10 . On the surface of the other end of the first power output shaft 5, a second power output shaft 10 is rotatably provided. During the rotation of the first power output shaft 5, it cannot directly drive the first power output shaft 5 to rotate. On the surface of the second power output shaft 10, a second clutch gear 9 capable of axially sliding is further provided. The second clutch gear 9 is also driven to slide by means of a slider and a rocker arm. The axial displacement of the second clutch gear 9 can achieve engagement or separation from the first drive gear 4.

[0035] The inner spline of the second clutch gear 9 is connected to the surface of the second power output shaft 10. On one side of the first drive gear 4, a spline tooth 41 adapted to the inside of the second clutch gear 9 is provided. On the surface of the second clutch gear 9, a second gear tooth 91 is provided. Inside the transmission housing 1, a reverse gear 11 is rotatably provided. The first power input shaft 2 is always engaged with the reverse gear 11. The sliding of the second clutch gear 9 can achieve engagement or separation from the first drive gear 4 and the reverse gear 11.

[0036] The second clutch gear 9 has three states on the surface of the second power output shaft 10, namely reverse gear, forward gear, and neutral gear.

[0037] Reverse gear: As shown in Figure 5 , the second gear tooth 91 of the second clutch gear 9 is engaged with the reverse gear 11. Since the first power input shaft 2 is always engaged with the reverse gear 11, during the rotation of the first power input shaft 2, it will drive the reverse gear 11 to drive the second clutch gear 9 to rotate. The second clutch gear 9 will simultaneously drive the second power output shaft 10 to rotate. Moreover, due to the speed change of the reverse gear 11, the rotation direction of the second power output shaft 10 at this time is different from that of the forward gear.

[0038] Neutral gear: On the basis of what is shown in Figure 5 , the second clutch gear 9 is shifted to the right until the second gear tooth 91 of the second clutch gear 9 is separated from the reverse gear 11. At this time, the first drive gear 4 cannot transmit power to the second clutch gear 9. Then the entire second power output shaft 10 is in a stationary state.

[0039] Forward gear: In Figure 5On the basis shown in the figure, the second clutch gear 9 is shifted to the right until the inside of the second clutch gear 9 meshes with the spline teeth 41 of the first driving gear 4. Then the first driving gear 4 will directly drive the second clutch gear 9 to rotate, and then the entire second power output shaft 10 is in a rotating state.

[0040] In this embodiment, please refer to Figure 2 , Figure 3 , Figure 8 and Figure 10 . A second clamping component 52 is further provided inside the first power output shaft 5. After the second clutch gear 9 meshes with the inside of the first driving gear 4, it can drive the second clamping component 52 so that the first driving gear 4 and the first power output shaft 5 rotate simultaneously.

[0041] The second clamping component 52 includes a first bearing 521, a second limiting spring 522 and a second limiting steel ball 523. The hydraulic cavity 529 between the surface of the first power output shaft 5 and the inside of the first driving gear 4 is sealed by the first bearing 521. A first oil passage 53 is further provided inside the first power output shaft 5. A second limiting through hole 55 is provided on the surface of the first power output shaft 5. A second limiting spring 522 is provided inside the second limiting through hole 55. Both ends of the second limiting spring 522 are connected with a second limiting steel ball 523. A first pressure relief oil passage 54 is further provided inside the first oil passage 53. A second pressure relief oil passage 42 and a third pressure relief oil passage 43 are provided inside the first driving gear 4. The center lines between the second pressure relief oil passage 42 and the third pressure relief oil passage 43 are perpendicular to each other. A third limiting spring 524 is provided inside the third pressure relief oil passage 43. A third limiting steel ball 525 is provided at the end of the third limiting spring 524. The position change of the third limiting steel ball 525 can block the third pressure relief oil passage 43.

[0042] The first oil passage 53 is connected to an external oil pump, and the third pressure relief oil passage 43 communicates with the inside of the entire transmission housing 1, and the inside of the transmission housing 1 is immersed in oil. The second limiting spring 522 always pulls the second limiting steel ball 523 to slide into the first oil passage 53.

[0043] An external oil pump transports hydraulic oil to the inside of the first oil passage 53. Then, the hydraulic oil flows through the first pressure relief oil passage 54, the second pressure relief oil passage 42, and the third pressure relief oil passage 43 to the inside of the transmission housing 1 in sequence. When the third pressure relief oil passage 43 fails to drain the hydraulic oil, the entire oil passage is in a pressure-holding state, and the hydraulic oil will push up each second limit steel ball 523, causing the second limit steel ball 523 to firmly get stuck inside the first driving gear 4. The first driving gear 4 can directly drive the first power output shaft 5 to rotate. Even when the first clutch gear 6 is in a separated state from the inside of the first driving gear 4, the first power output shaft 5 can still achieve rotation.

[0044] In order to further enable the third limit steel ball 525 to block the third pressure relief oil passage 43 when the second clutch gear 9 is in the forward gear position. A sealing film 526 and a steel ball boss 527 are provided on the surface of the third limit steel ball 525 close to the first driving gear 4. An annular boss 92 that can fit onto the steel ball boss 527 is provided on the side surface of the second clutch gear 9. A pressure relief diversion hole 528 is provided inside the third limit steel ball 525. The inner diameter of the pressure relief diversion hole 528 is smaller than the inner diameter of the second pressure relief oil passage 42. The top of the pressure relief diversion hole 528 communicates with the second pressure relief oil passage 42 and the side surface of the pressure relief diversion hole 528 communicates with the inside of the third pressure relief oil passage 43. A second limit annular groove 44 is further provided inside the first driving gear 4. A number of second steel ball limit plates 45 are provided at the top of the second limit annular groove 44. The second limit steel ball 523 can get stuck in the gap between adjacent second steel ball limit plates 45.

[0045] As Figure 8 shown in the figure. When the second clutch gear 9 is in the neutral position, the third limit spring 524 pushes the third limit steel ball 525 to the right, making the pressure relief diversion hole 528 in a conducting state with the bottom of the second pressure relief oil passage 42, and the hydraulic oil can normally flow out from the inside of the third pressure relief oil passage 43. The second limit spring 522 always pulls the second limit steel ball 523 to slide towards the inside of the first oil passage 53. When the first clutch gear 6 is in a separated state from the inside of the first driving gear 4, the first power output shaft 5 cannot rotate.

[0046] When the second clutch gear 9 is in the forward gear position, the inside of the second clutch gear 9 meshes with the first drive gear 4. The annular boss 92 will push the entire third limit ball 525 through the ball boss 527 to slide leftward against the elastic force of the third limit spring 524. Gradually, the pressure relief diversion hole 528 and the bottom of the second pressure relief oil passage 42 are no longer in a conducting state, and the largest middle area of the diameter of the third limit ball 525 will block the hydraulic oil from flowing out of the outlet of the third pressure relief oil passage 43. The hydraulic oil flowing down from the second pressure relief oil passage 42 will be retained in the area between the right side of the third limit ball 525 and the sealing film 526, but it cannot flow out to the outside. The entire oil passage is in a pressure maintaining state, and each second limit ball 523 will be stuck in the gap between the adjacent second ball limit plates 45.

[0047] In this embodiment, please refer to Figure 2 , Figure 3 , Figure 4 and Figure 6 . A wheel driving mechanism 3 is rotatably provided on the surface of the first power input shaft 2, a speed change transmission gear 7 is axially slidably provided on the surface of the wheel driving mechanism 3, and the wheel driving mechanism 3 rotates with the rotation of the speed change transmission gear 7. A plurality of speed change mechanisms 8 that are in transmission with the speed change transmission gear 7 are provided on the surface of the second power output shaft 10.

[0048] The speed change mechanism 8 includes a first speed change gear 81, a second speed change gear 82, and a third speed change gear 83. The first speed change gear 81, the second speed change gear 82, and the third speed change gear 83 are all fixedly connected to the surface of the second power output shaft 10. A worm driving gear 34 is rotatably provided on the surface of the first worm 31, and the worm driving gear 34 is always in a meshing state with the third speed change gear 83. The sliding of the speed change transmission gear 7 can be meshed with or separated from the first speed change gear 81 and the second speed change gear 82, and the sliding of the speed change transmission gear 7 can also be stuck in or separated from the inside of the worm driving gear 34.

[0049] The rotation of the second power output shaft 10 changes with the change of the left and right sliding position of the second clutch gear 9. During the rotation of the second power output shaft 10, the first speed change gear 81, the second speed change gear 82, and the third speed change gear 83 all rotate simultaneously. The combination of the speed change transmission gear 7 with different speed change gears can bring different rotation speeds.

[0050] The surface of the variable-speed transmission gear 7 is provided with a second annular transmission groove 71, a first transmission gear tooth 72 and a second transmission gear tooth 73. The side surface of the variable-speed transmission gear 7 is provided with a variable-speed transmission boss 74. The first transmission gear tooth 72 is adapted to the first variable-speed gear 81, the second transmission gear tooth 73 is adapted to the second variable-speed gear 82, and the variable-speed transmission boss 74 can be stuck inside the worm drive gear 34.

[0051] The inside of the second annular transmission groove 71 is also driven to slide by means of a push block and a rocker arm. During the sliding process of the variable-speed transmission gear 7, it is always in a meshed state with the speed-changing mechanism 8. The first transmission gear tooth 72 and the second transmission gear tooth 73 can be respectively adapted to the first variable-speed gear 81 and the second variable-speed gear 82. The variable-speed transmission gear 7 can also slide until the variable-speed transmission boss 74 is stuck inside the worm drive gear 34.

[0052] In this embodiment, please refer to Figure 2 、 Figure 6 and Figure 9 。 The wheel drive mechanism 3 includes a first worm 31, a first worm gear 32 and a first bevel gear 33. The surface of the first power output shaft 5 is rotatably provided with the first worm 31. The inside of the variable-speed transmission gear 7 is splined to the surface of the first worm 31. The end of the first worm 31 is drivingly connected with the first worm gear 32. The inside of the first worm gear 32 is drivingly connected with a plurality of first bevel gears 33. At least two of the first bevel gears 33 are drivingly connected with the wheel drive shaft 35.

[0053] When the worm drive gear 34 rotates, it cannot directly drive the first worm 31 to rotate. After the variable-speed transmission gear 7 is stuck inside the worm drive gear 34, it is the third variable-speed gear 83 that transmits power to the worm drive gear 34. The worm drive gear 34 transmits the power to the variable-speed transmission gear 7, and finally the variable-speed transmission gear 7 drives the entire first worm 31 to rotate.

[0054] No matter which gear the variable-speed transmission gear 7 is in, it can drive the first worm 31 to rotate during the rotation process. During the rotation of the first worm 31, it drives the first worm gear 32 to rotate, and the first worm gear 32 drives the first bevel gears 33 inside to rotate. Finally, the first bevel gears 33 drive each wheel drive shaft 35 to rotate.

[0055] The specific embodiments described in the text are only examples to illustrate the spirit of the present invention. Those skilled in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or use similar ways to replace them, but they will not deviate from the spirit of the present invention or exceed the scope defined by the appended claims.

Claims

1. A power transmission assembly inside a rear axle of a tractor, comprising a gearbox housing (1), a first power input shaft (2) arranged inside the gearbox housing (1), and characterized in that: The surface of the first power input shaft (2) is rotatably provided with a wheel drive mechanism (3); the end of the first power input shaft (2) is drivingly connected to a first drive gear (4); the interior of the first drive gear (4) is rotatably provided with a first power output shaft (5); one end surface of the first power output shaft (5) is axially slidably provided with a first clutch gear (6); the first power output shaft (5) rotates with the rotation of the first clutch gear (6); the axial displacement of the first clutch gear (6) can achieve engagement or disengagement with the first drive gear (4); the end of the first power output shaft (5) close to the outside of the gearbox housing (1) can The transmission is connected to the inside of the farming accessory. The surface of the other end of the first power output shaft (5) is rotatably provided with a second power output shaft (10). The surface of the wheel drive mechanism (3) is axially slidable and provided with a speed change transmission gear (7). The wheel drive mechanism (3) rotates with the rotation of the speed change transmission gear (7). The surface of the second power output shaft (10) is provided with a speed change mechanism (8) that is transmitted to the speed change transmission gear (7). The surface of the second power output shaft (10) is also provided with a second clutch gear (9) that is axially slidable. The axial displacement of the second clutch gear (9) can achieve engagement or separation with the first drive gear (4).

2. The power transmission assembly inside the rear axle of the tractor according to claim 1, characterized in that: A first clamping assembly (51) and a second clamping assembly (52) are provided inside the first power output shaft (5); after the first clutch gear (6) is axially displaced, the first clamping assembly (51) can clamp the position of the first clutch gear (6) relative to the first drive gear (4); after the second clutch gear (9) is meshed with the inside of the first drive gear (4), the second clamping assembly (52) can be driven to cause the first drive gear (4) and the first power output shaft (5) to rotate simultaneously.

3. The power transmission assembly inside the rear axle of the tractor according to claim 2, characterized in that: The internal spline of the first clutch gear (6) is connected to the surface of the first power output shaft (5); the surface of the first clutch gear (6) is provided with a first gear tooth (61) and a first annular transmission groove (62); the interior of the first drive gear (4) is provided with a gear groove adapted to the first gear tooth (61); the interior of the first annular transmission groove (62) is provided with a first push block (63); the end of the first push block (63) is hingedly connected to an external first rocker arm (66); the first push block (63) can push the first clutch gear (6) to engage or disengage with the interior of the first drive gear (4).

4. The power transmission assembly inside the rear axle of the tractor according to claim 3, characterized in that: The first clamping assembly (51) comprises a first limiting spring (511) and a first limiting steel ball (512); a first limiting through hole (513) is provided inside the first power output shaft (5); a center line of the first limiting through hole (513) is perpendicular to the axis of the first power output shaft (5); a first limiting spring (511) is provided inside the first limiting through hole (513); first limiting steel balls (512) are provided at both ends of the first limiting spring (511); a plurality of first limiting annular grooves (64) are provided inside the first clutch gear (6); a plurality of first steel ball limiting plates (65) are provided at the top of at least one of the first limiting annular grooves (64); the first limiting steel ball (512) can slide relative to the first limiting annular groove (64); and the first limiting steel ball (512) can be clamped by the gap between adjacent first steel ball limiting plates (65).

5. The power transmission assembly inside the rear axle of the tractor according to claim 4, characterized in that: The internal spline of the second clutch gear (9) is connected to the surface of the second power output shaft (10); one side of the first drive gear (4) is provided with spline teeth (41) adapted to the inside of the second clutch gear (9); the surface of the second clutch gear (9) is provided with second gear teeth (91); a reverse gear (11) is rotatably provided inside the transmission housing (1); the first power input shaft (2) is always meshed with the reverse gear (11); and the sliding of the second clutch gear (9) can mesh with or disengage the first drive gear (4) and the reverse gear (11).

6. The power transmission assembly inside the rear axle of the tractor according to claim 2, characterized in that: The second clamping assembly (52) comprises a first bearing (521), a second limiting spring (522) and a second limiting steel ball (523); a hydraulic cavity (529) between the surface of the first power output shaft (5) and the interior of the first driving gear (4) is sealed by the first bearing (521); a first oil circuit (53) is also provided inside the first power output shaft (5); a second limiting through hole (55) is provided on the surface of the first power output shaft (5); a second limiting spring (522) is provided inside the second limiting through hole (55); two ends of the second limiting spring (522) are connected to A second limiting steel ball (523) is provided, a first pressure relief oil circuit (54) is also provided inside the first oil circuit (53), a second pressure relief oil circuit (42) and a third pressure relief oil circuit (43) are provided inside the first driving gear (4), the center lines of the second pressure relief oil circuit (42) and the third pressure relief oil circuit (43) are perpendicular to each other, a third limiting spring (524) is provided inside the third pressure relief oil circuit (43), a third limiting steel ball (525) is provided at the end of the third limiting spring (524), and the position change of the third limiting steel ball (525) can block the third pressure relief oil circuit (43).

7. The power transmission assembly inside the rear axle of the tractor according to claim 6, characterized in that: A sealing film (526) and a steel ball boss (527) are provided on the surface of the third limiting steel ball (525) close to the first driving gear (4); an annular boss (92) capable of being fitted to the steel ball boss (527) is provided on the side of the second clutch gear (9); a pressure relief guide hole (528) is provided inside the third limiting steel ball (525); the inner diameter of the pressure relief guide hole (528) is smaller than the inner diameter of the second pressure relief oil circuit (42); the top of the pressure relief guide hole (528) is connected to the second pressure relief oil circuit (42) and the side of the pressure relief guide hole (528) is connected to the inside of the third pressure relief oil circuit (43); a second limiting annular groove (44) is further provided inside the first driving gear (4); a plurality of second steel ball limiting plates (45) are provided on the top of the second limiting annular groove (44); the second limiting steel ball (523) can be stuck in the gap between adjacent second steel ball limiting plates (45).

8. The power transmission assembly inside the rear axle of the tractor according to claim 5, characterized in that: The wheel drive mechanism (3) comprises a first worm (31), a first worm wheel (32) and a first bevel gear (33); the surface of the first power output shaft (5) is rotatably provided with the first worm (31); the internal spline of the speed change transmission gear (7) is connected to the surface of the first worm (31); the end of the first worm (31) is drivingly connected to the first worm wheel (32); the interior of the first worm wheel (32) is drivingly connected to a plurality of first bevel gears (33); and the interior of at least two first bevel gears (33) are drivingly connected to a wheel drive shaft (35).

9. The power transmission assembly inside the rear axle of the tractor according to claim 8, characterized in that: The speed change mechanism (8) comprises a first speed change gear (81), a second speed change gear (82) and a third speed change gear (83); the first speed change gear (81), the second speed change gear (82) and the third speed change gear (83) are all fixedly connected to the surface of the second power output shaft (10); a worm drive gear (34) is provided on the surface of the first worm (31); the worm drive gear (34) is always in a meshing state with the third speed change gear (83); the sliding of the speed change transmission gear (7) can mesh with or be separated from the first speed change gear (81) and the second speed change gear (82); the sliding of the speed change transmission gear (7) can also be stuck in or separated from the inside of the worm drive gear (34).

10. The power transmission assembly inside the rear axle of the tractor according to claim 8, characterized in that: The surface of the speed change transmission gear (7) is provided with a second annular transmission groove (71), a first transmission gear tooth (72) and a second transmission gear tooth (73); the side surface of the speed change transmission gear (7) is provided with a speed change transmission boss (74); the first transmission gear tooth (72) is adapted to fit the first speed change gear (81); the second transmission gear tooth (73) is adapted to fit the second speed change gear (82); and the speed change transmission boss (74) can be clamped inside the worm drive gear (34).

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