Power transmission assembly inside the tractor's rear axle

Abstract

The present invention relates to a power transmission assembly inside a tractor rear axle, comprising a gearbox housing and a first power input shaft. The first power input shaft is provided with a wheel drive mechanism on its surface, the end of the first power input shaft is connected to a first drive gear in a transmission manner, a first power output shaft is provided inside the first drive gear, one end of the first power output shaft is provided with a first clutch gear, the first power output shaft rotates with the rotation of the first clutch gear, the other end of the first power output shaft is provided with a second power output shaft, the surface of the wheel drive mechanism is provided with a speed change transmission gear, the surface of the second power output shaft is provided with a speed change mechanism, and the surface of the second power output shaft is provided with a second clutch gear. In the present invention, through a layout design, the left side of the first drive gear can serve as the driving force of the first clutch gear, and the right side of the first drive gear can serve as the driving force of the second clutch gear. The integrated structure improves transmission efficiency.

Description

Technical Field

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

[0002] Two-wheeled tractors are versatile machines widely used in agricultural production, renowned for their flexible operation and powerful power output. The power output shaft of these tractors can accommodate a variety of farming accessories, including snowplows, shovels, and hoes, making them highly practical and versatile. In winter, when snowplows and shovels are installed on a two-wheeled tractor, they can quickly clear snow from farmland and surrounding roads, clearing obstacles for spring planting. During the farming season, equipped with hoes, the two-wheeled tractor can efficiently plow and weed the fields, creating optimal soil conditions for crop growth. With their exceptional versatility and efficiency, two-wheeled tractors have significantly improved agricultural production efficiency and reduced farmers' workload, making them an indispensable tool in modern agricultural production.

[0003] The authorization announcement number is CN212950129U, which discloses a tractor rear axle structure. Combined with its specification and drawings, the front ends of the rear axle bevel gear shaft and the rear axle input shaft can be connected to the universal joint drive shaft to achieve articulated steering. By arranging the rear axle bevel gear shaft and the rear axle input shaft in combination with the reverse idler gear up and down, 8 forward gears and 2 reverse gears can be achieved.

[0004] However, the solution still has the following defects: 1. How to ensure that the tractor can accurately control the rotation of the power output shaft adapted to the farming accessories while realizing the forward and reverse functions is one of the issues that need to be considered; 2. How to realize that the agricultural machine automatically shifts gears to drive the farming accessories while the tractor is moving forward is also one of the issues that need to be considered; 3. How to highly integrate the design of the relationship between the variable speed power transmission and the power output shaft is also one of the issues that need to be considered. Summary of the Invention

[0005] The present invention mainly addresses the problems existing in the internal power transmission structure of the above-mentioned tractor rear axle, and invents a power transmission assembly inside the tractor rear axle. Through layout design, the left side of the first drive gear can be used as the driving force of the first clutch gear, and the right side of the first drive 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 automatically rotate.

[0006] The objectives of the present invention are achieved through the following technical solutions: a power transmission assembly inside a rear axle of a tractor, comprising a transmission housing, a first power input shaft disposed inside the transmission housing, a wheel drive mechanism rotatably provided on a surface of the first power input shaft, a first drive gear being transmission-connected at an end of the first power input shaft, a first power output shaft rotatably provided inside the first drive gear, a first clutch gear being axially slidably provided on one end surface of the first power output shaft, the first power output shaft rotating with rotation of the first clutch gear, axial displacement of the first clutch gear enabling engagement or disengagement with the first drive gear, an end of the first power output shaft near the outside of the transmission housing being transmission-connected to the interior of a farming accessory, a second power output shaft being rotatably provided on the other end surface of the first power output shaft, a speed change transmission gear being axially slidably provided on the surface of the wheel drive mechanism, the wheel drive mechanism rotating with rotation of the speed change transmission gear, a plurality of speed change mechanisms being transmission-connected to the speed change transmission gear on the surface of the second power output shaft, a second clutch gear being axially slidably provided on the surface of the second power output shaft, the second clutch gear being axially slidably provided, the second clutch gear being engaged or disengaged with the first drive gear by axial displacement.

[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 is internally engaged with the first drive gear, the second clamping assembly can be driven to make the first drive gear and the first power output shaft rotate simultaneously.

[0008] Preferably, the internal spline of the first clutch gear is connected to the surface of the first power output shaft, the surface of the first clutch gear is provided with first gear teeth and a first annular transmission groove, the interior of the first drive gear is provided with a tooth groove adapted to the first gear teeth, the interior of the first annular transmission groove is provided with a first push block, the end of the first push block is hingedly connected to the external first rocker arm, and the first push block can push the first clutch gear to engage or disengage with the interior of the first drive gear.

[0009] Preferably, the first clamping assembly 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 plurality of first limiting annular grooves are provided inside the first clutch gear, and a plurality of first steel ball limiting plates are provided on 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 stuck in the gap between adjacent first steel ball limiting plates.

[0010] Preferably, the internal spline of the second clutch gear is connected to the surface of the second power output shaft, one side of the first drive gear is provided with spline teeth adapted to the inside of the second clutch gear, the surface of the second clutch gear is provided with second gear teeth, and a reverse gear is rotatably provided inside the transmission housing, the first power input shaft is always engaged with the reverse gear, and the sliding of the second clutch gear can engage or disengage with the first drive gear and the reverse gear.

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

[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, and an annular boss that can fit on the steel ball boss is provided on the side of the second clutch gear. A pressure relief guide hole is provided inside the third limiting steel ball, and the inner diameter of the pressure relief guide hole is smaller than the inner diameter of the second pressure relief oil circuit. The top of the pressure relief guide hole is connected to the second pressure relief oil circuit and the side of the pressure relief guide hole is connected to the inside of the third pressure relief oil circuit. A second limiting annular groove is also provided inside the first driving gear, and a plurality of second steel ball limiting plates are provided on the top of the second limiting annular groove. The second limiting steel ball can be stuck in the gap between adjacent second steel ball limiting plates.

[0013] Preferably, the wheel drive mechanism includes a first worm, a first worm wheel, and a first bevel gear. The first worm is rotatably provided on the surface of the first power output shaft. The internal spline of the speed change transmission gear is connected to the surface of the first worm. The end of the first worm is drivingly connected to the first worm wheel. The internal transmission of the first worm wheel is connected to a plurality of first bevel gears. At least two of the first bevel gears are internally connected to the wheel drive shaft. This arrangement enables the wheel drive mechanism to drive the entire two-wheel tractor under the rotation of the speed change transmission gear.

[0014] Preferably, the speed change mechanism includes a first speed gear, a second speed gear and a third speed gear, the first speed gear, the second speed gear and the third speed 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 drive gear, the worm drive gear is always in a meshing state with the third speed gear, the sliding of the speed change transmission gear can engage or disengage with the first speed gear and the second speed gear, and the sliding of the speed change transmission gear can also be stuck or separated inside the worm drive gear.

[0015] Preferably, the surface of the speed-change transmission gear is provided with a second annular transmission groove, first transmission gear teeth, and second transmission gear teeth. A speed-change transmission boss is provided on the side of the speed-change transmission gear. The first transmission gear teeth are adapted to the first speed-change gear, and the second transmission gear teeth are adapted to the second speed-change gear. The speed-change transmission boss can be clamped inside the worm drive gear. This configuration enables the first clutch gear to be adapted to the speed-change gear of the speed-change mechanism.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] 1. The end of the first power output shaft serves as the power source for the agricultural machine accessories, and the second power output shaft serves as the power source for the forward and reverse movement of the entire two-wheel tractor. The first power output shaft is designed to rotate in the middle of the first drive gear, and the second power output shaft is designed to rotate 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 and second power output shafts. Through the clever layout design, the left side of the first drive gear can serve as the driving force for the first clutch gear, and the right side of the first drive gear can also serve as the driving force for the second clutch gear. The entire structure is highly integrated, maximizing the utilization of the power source and improving transmission efficiency.

[0018] 2. When the second clutch gear is in the forward gear position, the interior of the second clutch gear is meshed with the first drive gear. The annular boss will push the entire third limit steel ball through the steel ball boss to overcome the elastic force of the third limit spring and slide to the left. The pressure relief diversion hole and the bottom of the second pressure relief oil circuit are no longer in a conductive state, and the middle area with the largest diameter of the third limit steel ball will block the hydraulic oil from flowing out of the third pressure relief oil circuit outlet. The hydraulic oil flowing down the second pressure relief oil circuit will remain in the area between the right side of the third limit steel ball and the sealing film, but it cannot flow out to the outside. The entire oil circuit is in a pressure-maintaining state, and each second limit steel ball will be stuck in the gap between adjacent second steel ball limit plates. Through this design, the first power output shaft can automatically rotate when in the forward gear, which improves the degree of automation during tractor operation.

[0019] 3. The rotation of the second PTO shaft changes as the second clutch gear slides left and right. During rotation, the first, second, and third speed gears all rotate simultaneously. The speed transmission gear, combined with different speed gears, can produce different speeds. The entire transmission structure is highly integrated, reducing manufacturing costs for enterprises.

[0020] 4. By designing two first limiting annular grooves, the first clutch gear and the first power output shaft can be in either an engaged or disengaged state. After the axial displacement of the first clutch gear, the first clamping assembly can lock the position of the first clutch gear relative to the first drive gear. This locking does not completely lock the first clutch gear, but rather provides a preliminary limit on the sliding position of the first clutch gear. The user can not only use the maximum sliding range of the first clutch gear to determine the engagement state, but also use the first rocker arm to sense the torque changes of the first limiting steel ball, thereby determining whether the first clutch gear is stuck in the engaged gear or disengaged gear. This is more convenient for users and optimizes human-computer interaction. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 A perspective view of the present invention;

[0022] Figure 2 is a cross-sectional view of the present invention;

[0023] Figure 3 It is a partial cross-sectional view of the present invention;

[0024] Figure 4 This is a three-dimensional view of the present invention after the gearbox housing is removed;

[0025] Figure 5 This is a partial perspective view of the present invention after the gearbox housing is removed;

[0026] Figure 6This is a three-dimensional diagram of the present invention after the first clutch gear is removed from the surface of the first power output shaft;

[0027] Figure 7 is a cross-sectional view of the first clamping assembly in the present invention;

[0028] Figure 8 For the present invention Figure 2 A local enlarged view of area A;

[0029] Figure 9 For the present invention Figure 2 A local enlarged view of area B;

[0030] Figure 10 It is a cross-sectional view of the first driving gear in the present invention.

[0031] Markings in the figure: 1, gearbox 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 drive gear; 41, spline teeth; 42, second pressure relief oil circuit; 43, third pressure relief oil circuit; 44, second limiting annular groove; 45, second steel ball limiting plate; 5, first power output shaft; 51, first clamping assembly; 52, second clamping assembly; 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, first Three limit springs; 525, third limit steel ball; 526, sealing film; 527, steel ball boss; 528, pressure relief diversion hole; 529, hydraulic chamber; 6, first clutch gear; 61, first gear tooth; 62, first annular transmission groove; 63, first push block; 64, first limit annular groove; 65, first steel ball limit plate; 66, first rocker arm; 7, speed transmission gear; 71, second annular transmission groove; 72, first transmission gear tooth; 73, second transmission gear tooth; 74, speed transmission boss; 8, speed change mechanism; 81, first speed gear; 82, second speed gear; 83, third speed gear; 9, second clutch gear; 91, second gear tooth; 92, annular boss; 10, second power output shaft. DETAILED DESCRIPTION

[0032] The present invention will be further described below with reference to the embodiments shown in the accompanying drawings:

[0033] like Figure 1 、 Figure 2 and Figure 3As shown, a power transmission assembly inside a tractor rear axle includes a transmission housing 1, a first power input shaft 2 disposed inside the transmission housing 1, and a first drive gear 4 connected to the left end of the first power input shaft 2. A first power output shaft 5 is rotatably disposed inside the first drive gear 4.

[0034] The first driving gear 4 also rotates simultaneously during the rotation of the first power input shaft 2. The first driving gear 4 cannot directly drive the first power output shaft 5 to rotate during the rotation.

[0035] A first clutch gear 6 is axially slidably mounted on one end surface of the first power output shaft 5. The first power output shaft 5 rotates as the first clutch gear 6 rotates. Axial displacement of the first clutch gear 6 enables engagement or disengagement with the first drive gear 4. The end of the first power output shaft 5, which is adjacent to the exterior of the transmission housing 1, is transmission-connected to the interior of the farming accessory.

[0036] exist Figure 3 In the example, the first clutch gear 6 is disengaged from the first drive gear 4. The first drive gear 4 cannot simultaneously rotate the first clutch gear 6. When the first clutch gear 6 slides rightward until it engages with the first drive gear 4, the first drive gear 4 can rotate with the first clutch gear 6. This allows the first clutch gear 6 to simultaneously rotate the first power output shaft 5. At this point, the transmission system for the external farming accessories is connected to the end of the first power output shaft 5.

[0037] In this embodiment, please continue to refer to Figure 6 and Figure 10 :exist Figure 6 The first clutch gear 6 is removed from the surface of the first power output shaft 5. The interior of the first clutch gear 6 is spline-connected to the surface of the first power output shaft 5. The surface of the first clutch gear 6 is provided with first gear teeth 61 and a first annular transmission groove 62. The interior of the first drive gear 4 is provided with a tooth groove adapted to the first gear teeth 61. In this way, the first clutch gear 6 slides rightward until it is inside the first drive gear 4. The first gear teeth 61 can engage with the internal tooth groove of the first drive gear 4, realizing transmission between the first drive gear 4 and the first clutch gear 6.

[0038] like Figure 4 As shown, a first push block 63 is provided inside the first annular transmission groove 62, and the end of the first push block 63 is hingedly connected to the external first rocker arm 66. The first push block 63 can push the first clutch gear 6 to engage or disengage with the inside of the first driving gear 4.

[0039] The user rotates the bottom of the first rocker arm 66, thereby changing the position of the end of the first rocker arm 66. However, the hinged connection 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 retained within the first annular transmission groove 62. During rotation, the first rocker arm 66 drives the first push block 63 to push the entire first clutch gear 6 to slide along the left surface of the first power output shaft 5.

[0040] Please refer to Figure 6 and Figure 7 , Figure 7 The first clutch gear 6 is in a disengaged state from the first drive gear 4. After the first clutch gear 6 separates from the interior of the first drive gear 4 during its sliding process, it is necessary to limit the relative position of the first clutch gear 6. A first clamping assembly 51 is provided within the first power output shaft 5. After the first clutch gear 6 is axially displaced, the first clamping assembly 51 can lock the position of the first clutch gear 6 relative to the first drive gear 4. However, this locking does not firmly lock the first clutch gear 6, but rather provides a preliminary limit to the sliding position of the first clutch gear 6.

[0041] The first clamping assembly 51 includes 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. The 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. Several first limiting annular grooves 64 are provided inside the first clutch gear 6. Several first steel ball limiting plates 65 are provided on 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 stuck in the gap between adjacent first steel ball limiting plates 65.

[0042] The two first limiting annular grooves 64 represent the two states of engagement and disengagement between the first clutch gear 6 and the first power output shaft 5, respectively. After the first limiting steel ball 512 is locked within the first limiting annular groove 64, the elastic force generated by the first limiting spring 511 forces the first limiting steel ball 512 to fit within the first limiting annular groove 64. At this point, the first clutch gear 6 is initially locked relative to the first drive gear 4. When the first push block 63 pushes the first clutch gear 6 again, the internal teeth of the first clutch gear 6 compress the first limiting steel ball 512 toward the interior of the first limiting through hole 513. This process continuously compresses the first limiting spring 511, causing it to deform, thereby increasing the friction between the first limiting steel ball 512 and the interior of the first clutch gear 6. The user uses the first rocker arm 66 to sense the changes in the friction of the first limiting steel ball 512, thereby determining whether the first clutch gear 6 is stuck in the engaged or disengaged gear position.

[0043] It should be noted that when the first clutch gear 6 is in meshing state with the interior of the first drive gear 4, the first limiting steel ball 512 will be stuck in the gap between the adjacent first steel ball limiting plates 65, and the entire first clutch gear 6 cannot rotate relative to the first drive gear 4. The fit between the first clutch gear 6 and the first drive gear 4 is higher, and the torque is greater.

[0044] When the first clutch gear 6 is in a separated state from the interior of the first drive gear 4 , the entire first clutch gear 6 can rotate relative to the first drive gear 4 .

[0045] In this embodiment, please refer to Figure 3 、 Figure 5 、 Figure 6 and Figure 10 . A second power output shaft 10 is rotatably provided on the surface of the other end of the first power output shaft 5. The first power output shaft 5 cannot directly drive the first power output shaft 5 to rotate during the rotation process. The surface of the second power output shaft 10 is also provided with a second clutch gear 9 that can slide axially. 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 disengagement with the first drive gear 4.

[0046] 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 a spline tooth 41 adapted to the inside of the second clutch gear 9. The surface of the second clutch gear 9 is provided with a second gear tooth 91. The interior of the transmission housing 1 is rotatably provided with a reverse gear 11. The first power input shaft 2 is always engaged with the reverse gear 11. The sliding of the second clutch gear 9 can engage or disengage with the first drive gear 4 and the reverse gear 11.

[0047] 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.

[0048] Reverse gear: Figure 5 As shown in FIG, the second gear teeth 91 of the second clutch gear 9 mesh with the reverse gear 11. Since the first power input shaft 2 is always meshed with the reverse gear 11, the first power input shaft 2 will drive the reverse gear 11 during rotation, which in turn drives the second clutch gear 9. The second clutch gear 9 also drives the second power output shaft 10. Due to the additional speed change of the reverse gear 11, the rotation direction of the second power output shaft 10 is different from that of the forward gear.

[0049] Neutral: In Figure 5 Based on the diagram shown in , the second clutch gear 9 is shifted to the right until the second gear teeth 91 of the second clutch gear 9 are separated from the reverse gear 11. At this point, the first drive gear 4 cannot directly transmit power to the second clutch gear 9. The entire second power output shaft 10 is then in a stationary state.

[0050] Forward gear: Figure 5 On the basis shown in , the second clutch gear 9 is shifted to the right until the interior of the second clutch gear 9 is engaged with the spline teeth 41 of the first drive gear 4. Then the first drive gear 4 will directly drive the second clutch gear 9 to rotate, and the entire second power output shaft 10 is in a rotating state.

[0051] In this implementation, please refer to Figure 2 、 Figure 3 、 Figure 8 and Figure 10 The first power output shaft 5 is further provided with a second clamping assembly 52 , and the second clutch gear 9 is engaged with the interior of the first drive gear 4 to drive the second clamping assembly 52 so that the first drive gear 4 and the first power output shaft 5 rotate simultaneously.

[0052] The second clamping assembly 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 interior of the first driving gear 4 is sealed by the first bearing 521. The interior of the first power output shaft 5 is also provided with a first oil circuit 53. The surface of the first power output shaft 5 is provided with a second limiting through hole 55. The interior of the second limiting through hole 55 is provided with a second limiting spring 522. The two ends of the second limiting spring 522 are connected to the second limiting steel ball 523. The interior of the first oil circuit 53 is also provided with a first pressure relief oil circuit 54. The interior of the first driving gear 4 is provided with a second pressure relief oil circuit 42 and a third pressure relief oil circuit 43. The center lines of the second pressure relief oil circuit 42 and the third pressure relief oil circuit 43 are perpendicular to each other. The interior of the third pressure relief oil circuit 43 is provided with a third limiting spring 524. The end of the third limiting spring 524 is provided with a third limiting steel ball 525. The position change of the third limiting steel ball 525 can block the third pressure relief oil circuit 43.

[0053] The first oil passage 53 is connected to an external oil pump, while the third pressure relief oil passage 43 is connected to the interior of the entire transmission housing 1, which is soaked in oil. The second limit spring 522 always pulls the second limit steel ball 523 to slide into the interior of the first oil passage 53.

[0054] An external oil pump delivers hydraulic oil to the interior of the first oil circuit 53, whereupon the hydraulic oil flows through the first pressure relief oil circuit 54, the second pressure relief oil circuit 42, and the third pressure relief oil circuit 43 into the interior of the transmission housing 1. When the third pressure relief oil circuit 43 is unable to discharge the hydraulic oil, the interior of the entire oil circuit is in a pressure-maintaining state, and the hydraulic oil pushes up each second limiting steel ball 523, causing the second limiting steel ball 523 to be firmly stuck inside the first drive gear 4. The first drive gear 4 can directly drive the first power output shaft 5 to rotate. Even when the first clutch gear 6 is separated from the interior of the first drive gear 4, the first power output shaft 5 can still rotate.

[0055] To further ensure that the second clutch gear 9 is in the forward gear position, the third limiting steel ball 525 can block the third pressure relief oil passage 43. The surface of the third limiting steel ball 525 near the first drive gear 4 is provided with a sealing film 526 and a steel ball boss 527. The side of the second clutch gear 9 is provided with an annular boss 92 that can fit against the steel ball boss 527. The interior of the third limiting steel ball 525 is provided with a pressure relief guide hole 528. The inner diameter of the pressure relief guide hole 528 is smaller than the inner diameter of the second pressure relief oil passage 42. The top of the pressure relief guide hole 528 is connected to the second pressure relief oil passage 42, and the side of the pressure relief guide hole 528 is connected to the interior of the third pressure relief oil passage 43. The interior of the first drive gear 4 is also provided with a second limiting annular groove 44. The top of the second limiting annular groove 44 is provided with a plurality of second steel ball limiting plates 45. The second limiting steel ball 523 can be stuck in the gap between adjacent second steel ball limiting plates 45.

[0056] like Figure 8 When the second clutch gear 9 is in neutral, the third limiting spring 524 pushes the third limiting steel ball 525 to the right, establishing a connection between the pressure relief guide hole 528 and the bottom of the second pressure relief oil passage 42, allowing hydraulic oil to flow normally from the interior of the third pressure relief oil passage 43. The second limiting spring 522 constantly pulls the second limiting steel ball 523 to slide into the interior of the first oil passage 53. When the first clutch gear 6 is separated from the interior of the first drive gear 4, the first power output shaft 5 cannot rotate.

[0057] When the second clutch gear 9 is in the forward gear position, the interior of the second clutch gear 9 is meshed with the first drive gear 4. The annular boss 92 will push the entire third limiting steel ball 525 to slide to the left under the elastic force of the third limiting spring 524 through the steel ball boss 527. Gradually, the pressure relief guide hole 528 and the bottom of the second pressure relief oil circuit 42 are no longer in a conductive state, and the middle area with the largest diameter of the third limiting steel ball 525 will block the hydraulic oil from flowing out of the outlet of the third pressure relief oil circuit 43. The hydraulic oil flowing down the second pressure relief oil circuit 42 will remain in the area between the right side of the third limiting steel ball 525 and the sealing film 526, but it cannot flow out to the outside. The entire oil circuit is in a pressure-maintaining state, and each second limiting steel ball 523 will be stuck in the gap between adjacent second steel ball limiting plates 45.

[0058] In this embodiment, please refer to Figure 2 、 Figure 3 、 Figure 4 and Figure 6The first power input shaft 2 has a wheel drive mechanism 3 rotatably mounted on its surface. A speed change gear 7 is axially slidably mounted on the surface of the wheel drive mechanism 3. The wheel drive mechanism 3 rotates as the speed change gear 7 rotates. The second power output shaft 10 has a plurality of speed change mechanisms 8 mounted on its surface that transmit power to the speed change gear 7.

[0059] 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. The surface of the first worm 31 is rotatably provided with a worm drive gear 34. The worm drive gear 34 is always in meshing state with the third speed change gear 83. The sliding of the speed change transmission gear 7 can be engaged or disengaged with 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 or disengaged inside the worm drive gear 34.

[0060] The rotation of the second power output shaft 10 changes as the second clutch gear 9 slides left and right. During the rotation of the second power output shaft 10, the first speed gear 81, the second speed gear 82, and the third speed gear 83 all rotate simultaneously. The speed transmission gear 7 can be combined with different speed gears to produce different speeds.

[0061] The surface of the speed-changing 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, and the side of the speed-changing transmission gear 7 is provided with a speed-changing transmission boss 74. The first transmission gear tooth 72 is adapted to the first speed-changing gear 81, and the second transmission gear tooth 73 is adapted to the second speed-changing gear 82. The speed-changing transmission boss 74 can be stuck inside the worm drive gear 34.

[0062] The interior of the second annular transmission groove 71 is also driven to slide by a push block and rocker arm. During the sliding process, the speed change transmission gear 7 is constantly engaged with the speed change mechanism 8. The first transmission gear teeth 72 and the second transmission gear teeth 73 are adapted to fit the first speed change gear 81 and the second speed change gear 82, respectively. The speed change transmission gear 7 can also slide until the speed change transmission boss 74 is engaged with the interior of the worm drive gear 34.

[0063] In this embodiment, please refer to Figure 2 、 Figure 6 and Figure 9The wheel drive mechanism 3 includes a first worm 31, a first worm wheel 32, and a first bevel gear 33. The first worm 31 is rotatably provided on the surface of the first power output shaft 5. 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 connected to the first worm wheel 32. The first worm wheel 32 is internally connected to a plurality of first bevel gears 33. At least two of the first bevel gears 33 are internally connected to the wheel drive shaft 35.

[0064] The worm drive gear 34 cannot directly drive the first worm 31 when it rotates. After the speed change gear 7 is stuck inside the worm drive gear 34, the third speed change gear 83 transmits power to the worm drive gear 34, and the worm drive gear 34 transmits the power to the speed change gear 7. Finally, the speed change gear 7 drives the entire first worm 31 to rotate.

[0065] Regardless of the gear position of the speed change transmission gear 7, the speed change transmission gear 7 rotates and simultaneously drives the first worm 31 to rotate. The rotation of the first worm 31 drives the first worm wheel 32 to rotate, and the first worm wheel 32 drives the first bevel gear 33 inside to rotate. Ultimately, the first bevel gear 33 drives each wheel drive shaft 35 to rotate.

[0066] The specific embodiments described herein are merely illustrative of the spirit of the present invention. Persons skilled in the art may make various modifications, additions, or substitutions to the described specific embodiments without departing from the spirit of the present invention or exceeding the scope of 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 transmission-connected with 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 slidable 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 separation 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 be transmission-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), and the surface of the wheel drive mechanism (3) is axially slidable 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 can slide axially; the axial displacement of the second clutch gear (9) can achieve engagement or separation with the first drive gear (4); the interior of the first power output shaft (5) is provided with a first clamping component (51) and a second clamping component (52); 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 drive gear (4); after the second clutch gear (9) is engaged with the interior of the first drive gear (4), it can drive the second clamping component (52) to make the first drive gear (4) and the first power output shaft (5) rotate simultaneously.

2. The power transmission assembly inside the rear axle of the tractor according to claim 1, 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 tooth 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 the external first rocker arm (66), and 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).

3. The power transmission assembly inside the rear axle of the tractor according to claim 2, characterized in that: The first clamping assembly (51) includes 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).

4. The power transmission assembly inside the rear axle of the tractor according to claim 3, 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 interior of the second clutch gear (9), the surface of the second clutch gear (9) is provided with second gear teeth (91), the interior of the transmission housing (1) is rotatably provided with a reverse gear (11), the first power input shaft (2) is always engaged with the reverse gear (11), and the sliding of the second clutch gear (9) can engage or disengage with the first drive gear (4) and the reverse gear (11).

5. The power transmission assembly inside the rear axle of the tractor according to claim 1, characterized in that: The second clamping assembly (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 interior of the first driving gear (4) is sealed by the first bearing (521). The interior of the first power output shaft (5) is also provided with a first oil circuit (53). The surface of the first power output shaft (5) is provided with a second limiting through hole (55). The interior of the second limiting through hole (55) is provided with a second limiting spring (522). The two ends of the second limiting spring (522) are connected A second limiting steel ball (523) is provided, a first pressure relief oil circuit (54) is further 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 between 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).

6. The power transmission assembly inside the rear axle of the tractor according to claim 5, characterized in that: The surface of the third limiting steel ball (525) close to the first driving gear (4) is provided with a sealing film (526) and a steel ball boss (527), the side of the second clutch gear (9) is provided with an annular boss (92) that can fit on the steel ball boss (527), the interior of the third limiting steel ball (525) is provided with a pressure relief guide hole (528), 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 interior of the third pressure relief oil circuit (43), the interior of the first driving gear (4) is also provided with a second limiting annular groove (44), the top of the second limiting annular groove (44) is provided with a plurality of second steel ball limiting plates (45), and the second limiting steel ball (523) can be stuck in the gap between adjacent second steel ball limiting plates (45).

7. The power transmission assembly inside the rear axle of a tractor according to claim 4, 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 connected to the first worm wheel (32); the interior of the first worm wheel (32) is connected to a plurality of first bevel gears (33); and the interior of at least two first bevel gears (33) is connected to the wheel drive shaft (35).

8. The power transmission assembly inside the rear axle of the tractor according to claim 7, characterized in that: 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), wherein 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), and the surface of the first worm (31) is provided with a worm drive gear (34), and the worm drive gear (34) is always in a meshing state with the third speed change gear (83), and the sliding of the speed change transmission gear (7) can mesh with or separate 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 or separated inside the worm drive gear (34).

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

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