Self-propelled crawler-type agricultural machine gearbox assembly

Abstract

The invention relates to the technical field of gearbox assemblies, in particular to a self-propelled crawler-type agricultural machine gearbox assembly which comprises a shell, an output shaft and a gear shifting gear train, and the gear shifting gear train comprises a gear shifting wheel, a joint gear ring, a synchronous ring, a splined hub and a joint sleeve; by arranging a conical friction surface clearance fit structure of the synchronizing ring and the joint gear ring, rotating speed synchronization is achieved through friction of the synchronizing ring and the joint gear ring during gear shifting during advancing, and hard impact generated by the rotating speed difference at the meshing moment of the joint sleeve, the joint gear ring and the splined hub is avoided; the problems of tooth surface peeling, pitting corrosion and tooth end back taper abrasion caused by frequent gear shifting friction and impact of the joint gear under the direct action of large torque of an engine are solved, the stability and smoothness of power transmission during gear shifting of the gearbox assembly of the self-propelled crawler-type agricultural machine are guaranteed, and the service life of the gear is prolonged.

Description

Technical Field

[0001] This invention relates to the field of gearbox assembly technology, specifically to a self-propelled tracked agricultural machinery gearbox assembly. Background Technology

[0002] Self-propelled tracked agricultural machinery is a core piece of equipment in modern agriculture for dealing with complex terrain. Its operation requires continuous high torque output and withstands high impacts in environments filled with impurities. The gearbox assembly is the core transmission component of this machinery. In modern agricultural production, self-propelled tracked agricultural machinery needs to operate in complex field environments such as hills, mud, and areas with lots of gravel. To adapt to different farming needs, the gearbox needs frequent operation for gear shifting. During this process, the shift gears and engagement gears within the gearbox repeatedly mesh and disengage, causing their tooth surfaces to wear rapidly due to continuous friction and torque impact. As the usage time increases, the meshing clearance caused by wear gradually widens. When the clearance exceeds the design threshold, under conditions of machinery vibration or torque fluctuations, the shift gears and engagement gears are prone to axial movement, eventually leading to gear skipping. This directly disrupts the continuity of power transmission in the gearbox, affecting its normal operation.

[0003] To address the aforementioned problems, existing technologies have proposed several solutions. For example, patent application CN202311500173.5 discloses a self-propelled tracked agricultural machinery gearbox assembly. This solution includes a housing, with a first rotating shaft located at one end inside the housing, a second rotating shaft located near the first rotating shaft, and a third rotating shaft located near the second rotating shaft. A pair of sliding rods are fixedly connected inside the housing near the first rotating shaft, and an anti-gear-jumping mechanism is slidably connected to each of the sliding rods. A gear lever is fixedly connected to the upper surface of the end of the housing near the first rotating shaft. This invention effectively prevents gear skipping by creating grooves on the slide rod and setting an anti-skipping mechanism on the slide rod. Although the above solution solves the gear skipping problem, there are still some issues regarding tooth surface wear under high torque, high impact, and impurity environments. When shifting gears in a self-propelled tracked agricultural machine, the high torque continuously output by the engine is applied to the engaging gear through the engaging sleeve. This can easily lead to tooth surface peeling, pitting, and tapered wear at the tooth ends under the friction of frequent gear shifting and high torque impact, thereby reducing meshing accuracy, shortening gear life, and affecting the stability of power transmission in the gearbox. Summary of the Invention

[0004] The purpose of this invention is to provide a self-propelled tracked agricultural machinery gearbox assembly to solve the problem that when shifting gears in existing self-propelled tracked agricultural machinery, the large torque continuously output by the engine is applied to the engaging gear through the engaging sleeve. This causes the engaging gear to experience tooth surface peeling, pitting, and tooth tip tapering wear under the friction of frequent gear shifting and the impact of large torque, thereby reducing meshing accuracy, shortening gear life, and affecting the stability of power transmission of the gearbox.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A self-propelled tracked agricultural machinery gearbox assembly includes a housing, an input shaft, an input gear set, an intermediate shaft, an intermediate gear set, an output shaft, an output gear set, a reverse gear shaft, a shift gear system, and a shift actuator. The input shaft, intermediate shaft, output shaft, and reverse gear shaft are all rotatably connected within the housing. The input gear set, intermediate gear set, and output gear set are respectively mounted on the input shaft, intermediate shaft, and output shaft. The shift gear system is mounted on the output gear set. The shift actuator is mounted within the housing and connected to the shift gear system. The shift gear system includes a shift wheel, a engagement gear ring, a synchronizer ring, a splined hub, and a engagement sleeve. The shift wheel is coaxially connected to the output shaft. The engagement gear ring is coaxially fixedly mounted on the end face of the shift wheel. Both the outer ring of the engagement gear ring and the inner ring of the synchronizer ring have tapered friction surfaces. The tapered friction surface of the synchronizer ring and the tapered friction surface of the engagement gear ring are clearance-fitted. The splined hub... The gearbox is slidably connected to the output shaft via an involute spline, and the engaging sleeve is slidably connected to the splined hub coaxially. The engaging gear ring, synchronizing ring, and outer ring of the splined hub are all machined with external splines of the same module and number of teeth. The inner ring of the engaging sleeve is machined with internal splines that mate with the splined hub. By setting a clearance fit structure between the synchronizing ring and the engaging gear ring with a conical friction surface, speed synchronization is achieved through friction between the two during gear shifting, avoiding the hard impact caused by speed difference during the meshing of the engaging sleeve with the engaging gear ring and splined hub. This avoids the problems of tooth surface peeling, pitting, and tooth tip tapering wear caused by frequent gear shifting friction and impact under the direct action of high engine torque. It ensures the meshing accuracy, power transmission stability, and smoothness of the self-propelled tracked agricultural machinery gearbox assembly during gear shifting, extends gear life, and improves the structural reliability and long-term operating capability of the self-propelled tracked agricultural machinery gearbox assembly under high torque conditions.

[0006] Preferably, the splined hub has multiple sliding grooves, each containing a locking pin slidably connected to it. Spring rings are installed at both ends of the coupling sleeve, and each spring ring is connected to both ends of the locking pins. Multiple locking grooves, corresponding in number to the sliding grooves, are evenly distributed circumferentially on the end face of the synchronizing ring. These locking grooves are adapted to the locking pins. By creating sliding grooves on the splined hub and slidably connecting the locking pins, and utilizing the spring rings at both ends of the coupling sleeve to connect the locking pins, the locking pins mate with the matching locking grooves on the end face of the synchronizing ring. The spring rings not only provide a stable preload to the locking pins to maintain their tight fit with the locking grooves, but also... When shifting gears abruptly, the design uses its own elastic deformation to buffer the impact force, preventing the impact force from being directly transmitted to the locking pin and forcibly pushing the conical friction surface of the synchronizing ring into contact with the engagement gear ring. This design not only prevents the engagement sleeve from engaging prematurely when the shifting synchronization is not completed, but also avoids friction surface impact damage caused by abrupt shifting. At the same time, it solves the problems of shifting impact and tooth surface damage caused by loose locking, ensuring the synchronization accuracy, engagement smoothness and friction surface structure integrity of the gearbox shifting process, improving the impact resistance and operational reliability of the shifting mechanism, and thus ensuring the continuity of power transmission and the service life of components.

[0007] Preferably, the locking groove and the locking pin adopt a transition fit, and the head of the locking pin is provided with a 15°-20° guide slope. The guide slope and the slope of the locking groove form a wedge fit. The transition fit between the locking groove and the locking pin ensures the fit accuracy. The 15°-20° guide slope of the locking pin head and the wedge fit with the slope of the locking groove achieve rigid locking when synchronization is not completed and gradual unlocking after synchronization is completed. This design avoids gear skipping caused by excessive locking clearance during high torque shifting of the self-propelled tracked agricultural machinery gearbox, impact noise caused by excessively loose fit, and locking jamming caused by impurities. At the same time, the wedge structure can buffer the impact force at the moment of meshing and reduce tooth surface wear. These designs ensure the shifting synchronization accuracy, locking reliability and structural fatigue resistance of the self-propelled tracked agricultural machinery gearbox assembly under high impact conditions, improve meshing stability and component service life, and ensure continuous operation of the self-propelled tracked agricultural machinery in complex field environments.

[0008] Preferably, each of the multiple locking pins is equipped with a compensating plate on the side near the synchronizing ring. These compensating plates are C-shaped, with their ends connected to the inner walls of the locking pins and locking grooves, respectively. By installing C-shaped compensating plates on the side of the locking pins near the synchronizing ring and connecting their ends to the locking pins and the inner walls of the locking grooves, the elastic deformation characteristics of the C-shaped structure can automatically compensate for the fit clearance between the locking pins and locking grooves caused by long-term wear. Simultaneously, the preload of the compensating plates maintains the fit between the two. This design avoids problems such as decreased locking force and gear skipping caused by wear of the locking pair after long-term high-torque, high-impact operation of the self-propelled tracked agricultural machinery gearbox, as well as meshing impact and impurity jamming caused by excessive fit clearance. These designs ensure the long-term reliability, shifting synchronization stability, and structural wear resistance of the self-propelled tracked agricultural machinery gearbox assembly locking mechanism, extend the service life of the locking components, and ensure continuous and stable operation of the self-propelled tracked agricultural machinery under complex field conditions.

[0009] Preferably, the outer spline of the synchronizing ring is machined with a spline surface, which adopts a "drum-shaped trimming" design, and the trimming amount of the spline surface is 0.08-0.12mm. By adopting a "drum-shaped trimming" design with a trimming amount of 0.08-0.12mm on the spline surface of the outer spline of the synchronizing ring, and increasing the root fillet radius to 1.2-1.5mm, progressive contact and uniform load distribution are achieved during spline meshing. At the same time, increasing the root fillet radius reduces stress concentration. This design avoids the self-propelled track... Under conditions of high torque transmission and high impact, belt-driven agricultural machinery gearboxes are designed to prevent tooth surface spalling and pitting caused by spline meshing under uneven load, as well as tooth root fracture caused by stress concentration. They also reduce the risk of impurities getting stuck on the spline meshing surface. These designs ensure the reliability of the meshing between the synchronizer ring and the coupling sleeve in the self-propelled tracked agricultural machinery gearbox assembly, as well as the high torque carrying capacity and impact fatigue resistance. They also extend the service life of the synchronizer ring and ensure the smooth shifting and continuous operational stability of the self-propelled tracked agricultural machinery in complex field operations.

[0010] Preferably, the synchronizing ring is divided into an upper half ring and a lower half ring, which are connected to each other by bolts. By designing the synchronizing ring as a split structure of upper and lower half rings and fastening it with bolts, the synchronizing ring can be installed and replaced without disassembling the entire gearbox by separating the upper and lower half rings. This design avoids the problems of long maintenance cycles, high labor costs, and secondary damage to other components caused by the need to completely disassemble the shaft system and gear set when the synchronizing ring is damaged in self-propelled tracked agricultural machinery gearboxes. At the same time, it reduces the difficulty of replacing the synchronizing ring in environments with many impurities. These designs ensure the convenience and efficiency of maintenance of the self-propelled tracked agricultural machinery gearbox assembly, shorten downtime due to failure, indirectly improve the continuity of agricultural machinery operation, and ensure the structural stability and power transmission reliability of the synchronizing ring under high torque and high impact conditions through reliable bolt connection.

[0011] Preferably, the conical friction surface of the engaging gear ring is machined with circumferential oil grooves, which are distributed in a spiral shape with a spiral angle of 15°-20°. By machining circumferential oil grooves in a spiral shape at 15°-20° on the conical friction surface of the engaging gear ring, the "pumping effect" generated by the spiral structure when the engaging gear ring rotates can be used to uniformly guide the lubricating oil to the friction surface and store it, while simultaneously discharging the debris and impurities generated by friction with the oil. This design avoids problems such as sintering and increased wear of the friction surface between the synchronizing ring and the engaging gear ring due to insufficient lubrication during high-torque shifting in self-propelled tracked agricultural machinery gearboxes, as well as friction coefficient fluctuations and synchronization failures caused by debris accumulation in a multi-impurity environment. These designs ensure the frictional stability, component wear resistance, and lubrication reliability of the self-propelled tracked agricultural machinery gearbox assembly during the synchronization phase, extend the service life of the synchronizing ring and the engaging gear ring, and ensure the smoothness and synchronization effectiveness of shifting in self-propelled tracked agricultural machinery under high-load and multi-impurity conditions.

[0012] Preferably, the synchronizing ring is made of alloy steel, and the conical friction surface of the engaging gear ring is treated with "carburizing and quenching + low-temperature tempering", achieving an outer ring hardness of 60-62 HRC and an inner ring hardness of 30-35 HRC. The conical friction surface of the synchronizing ring is coated with a tungsten carbide wear-resistant coating with a surface roughness Ra≤0.4μm. By using alloy steel to manufacture the synchronizing ring and treating the conical friction surface of the engaging gear ring with "carburizing and quenching + low-temperature tempering", a gradient hardness of 60-62 HRC for the outer ring and 30-35 HRC for the inner ring is achieved. Simultaneously, a tungsten carbide wear-resistant coating with a surface roughness Ra≤0.4μm is applied to the conical friction surface of the synchronizing ring. The tungsten carbide wear-resistant coating balances the surface wear resistance of components with the core impact toughness. This design avoids problems such as friction surface collapse and tooth root fracture caused by insufficient material strength in the synchronizing ring and engaging gear ring of self-propelled tracked agricultural machinery gearboxes under high torque transmission and high impact conditions, as well as synchronization failure and shifting sticking caused by excessive wear in environments with many impurities. These designs ensure the high torque carrying capacity, high impact resistance, and long-term wear resistance of the synchronization device of the self-propelled tracked agricultural machinery gearbox assembly, extend the service life of the synchronization components, reduce maintenance costs, and ensure the reliability of shifting and the continuity of operation of self-propelled tracked agricultural machinery under complex field conditions.

[0013] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. This invention provides conical friction surfaces on both the outer ring of the engagement gear ring and the inner ring of the synchronizing ring. By setting a clearance fit structure between the conical friction surfaces of the synchronizing ring and the engagement gear ring, speed synchronization is achieved through friction between the two during gear shifting, avoiding the hard impact caused by speed difference during the meshing of the engagement sleeve with the engagement gear ring and splined hub. This avoids the problems of tooth surface peeling, pitting, and tooth tip tapering wear caused by frequent gear shifting friction and impact under the direct action of high engine torque, ensuring the stability and smoothness of power transmission during gear shifting in the self-propelled tracked agricultural machinery gearbox assembly, and extending the service life of the gears.

[0014] 2. This invention features multiple sliding grooves on the splined hub, each containing a locking pin slidably connected to it. Spring rings are installed at both ends of the engagement sleeve. When gear shifting is performed forcefully, the spring rings cushion the impact through their elastic deformation, preventing the impact from being directly transmitted to the locking pins and forcibly pushing the synchronizing ring into contact with the conical friction surface of the engagement gear ring. This design not only prevents premature engagement of the engagement sleeve by the cooperation of the locking pins and locking grooves before gear shifting synchronization is complete, but also avoids friction surface impact damage caused by forceful gear shifting. Simultaneously, it solves the problems of shifting impact and gear surface damage caused by loose locking mechanisms.

[0015] 3. This invention features a 15°-20° guide slope at the head of the locking pin, which forms a wedge-shaped fit with the slope of the locking groove. This avoids gear skipping caused by excessive locking clearance during high-torque shifting in self-propelled tracked agricultural machinery gearboxes, impact noise caused by loose fit, and locking jamming caused by impurities. Simultaneously, the wedge-shaped structure buffers the impact force at the moment of engagement, reducing tooth surface wear. This ensures the shifting synchronization accuracy, locking reliability, and structural fatigue resistance of the self-propelled tracked agricultural machinery gearbox assembly under high-impact conditions, improves meshing stability and component lifespan, and ensures continuous operation of self-propelled tracked agricultural machinery in complex field environments. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 2 This is a schematic diagram of the input shaft and output shaft in the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 3 This is an exploded view of the front axle of the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 4 This is an exploded view of the rear axle of the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 5 This is a schematic diagram of the shift gear system in the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 6 This is a cross-sectional view of the shift gear system in the self-propelled tracked agricultural machinery gearbox assembly of the present invention; Figure 7 This is a diagram showing the state of the shift gear system in the self-propelled tracked agricultural machinery gearbox assembly before shifting gears in this invention. Figure 8 For the present invention Figure 6 A magnified view of a portion of point A in the middle.

[0017] In the diagram: 1. Housing; 201. Input shaft; 202. Input gear set; 301. Output shaft; 302. Output gear set; 401. Upper half ring; 402. Lower half ring; 5. Shift gear system; 501. Shift wheel; 502. Engaging gear ring; 503. Synchronizing ring; 504. Splined hub; 505. Engaging sleeve; 6. Conical friction surface; 701. External spline; 702. Internal spline; 801. Slide groove; 802. Locking pin; 803. Spring ring; 804. Locking groove; 805. Guide slope; 806. Compensating plate; 807. Splined surface; 901. Circumferential oil groove; 902. Coating. Detailed Implementation

[0018] Please see Figures 1 to 8 This invention provides a self-propelled tracked agricultural machinery gearbox assembly, the technical solution of which is as follows: Please refer to a self-propelled tracked agricultural machinery gearbox assembly. Figures 1 to 8The system includes a housing 1, an input shaft 201, an input gear set 202, an intermediate shaft, an intermediate gear set, an output shaft 301, an output gear set 302, a reverse gear shaft, a shift gear system 5, and a shift actuator. The input shaft 201, intermediate shaft, output shaft 301, and reverse gear shaft are all rotatably connected within the housing 1. The input gear set 202, intermediate gear set, and output gear set 302 are respectively mounted on the input shaft 201, intermediate shaft, and output shaft 301. The shift gear system 5 is mounted on the output gear set 301. On the 02, the shifting actuator is installed inside the housing 1 and connected to the shifting gear system 5. The shifting gear system 5 includes a shift wheel 501, an engagement gear ring 502, a synchronizing ring 503, a splined hub 504, and an engagement sleeve 505. The shift wheel 501 is coaxially connected to the output shaft 301, and the engagement gear ring 502 is coaxially fixedly installed on the end face of the shift wheel 501. Both the outer ring of the engagement gear ring 502 and the inner ring of the synchronizing ring 503 are provided with conical friction surfaces 6. The conical friction surface 6 of the engagement gear ring 502 is clearance-fitted with the conical friction surface 6 of the engagement gear ring 502. The splined hub 504 is slidably connected to the output shaft 301 via an involute spline. The engagement sleeve 505 is coaxially slidably connected to the splined hub 504. The outer rings of the engagement gear ring 502, the synchronizing ring 503, and the splined hub 504 are all machined with external splines 701 of the same module and number of teeth. The inner ring of the engagement sleeve 505 is machined with internal splines 702 that mate with the splined hub 504. The conical friction surface 6 of the engagement gear ring 502... The friction surface 6 is machined with circumferential oil grooves 901. The circumferential oil grooves 901 of the engaging gear ring 502 are distributed in a "spiral" shape with a helix angle of 18°. The synchronizing ring 503 is made of alloy steel. The conical friction surface 6 of the engaging gear ring 502 is treated with "carburizing and quenching + low temperature tempering", with an outer ring hardness of 60HRC and an inner ring hardness of 34HRC. The conical friction surface 6 of the synchronizing ring 503 is provided with a tungsten carbide wear-resistant coating 902, and the surface roughness Ra of the coating 902 is 0.The splined hub 504 has a diameter of 4μm and multiple sliding grooves 801. Locking pins 802 are slidably connected within each of the multiple sliding grooves 801. Spring rings 803 are installed at both ends of the coupling sleeve 505, and each spring ring 803 is connected to both ends of the multiple locking pins 802. Multiple locking grooves 804, corresponding in number to the sliding grooves 801, are evenly distributed circumferentially on the end face of the synchronizing ring 503. The locking grooves 804 are adapted to the locking pins 802, and the locking grooves 804 and locking pins 802 are in a transition fit. The head of the locking pin 802 has a 16° guide slope 805, which intersects with the slope of the locking groove 804. A wedge-shaped fit is formed. Each of the multiple locking pins 802 has a compensating plate 806 mounted on the side near the synchronizing ring 503. The multiple compensating plates 806 are C-shaped, and their two ends are connected to the inner walls of the locking pins 802 and the locking grooves 804, respectively. The outer spline 701 of the synchronizing ring 503 has a splined surface 807 machined on it. The splined surface 807 adopts a "drum-shaped trimming" design, with a trimming amount of 0.1 mm and an increased root radius of 1.4 mm. The synchronizing ring 503 is divided into an upper half-ring 401 and a lower half-ring 402, which are connected to each other by bolts.

[0019] When working, please refer to Figures 1 to 8 After the engine starts, power is transmitted to the gearbox input shaft 201 via the clutch. The input shaft 201 drives the input gear set 202 to rotate. The input gear set 202 meshes with the intermediate gear set on the intermediate shaft, transmitting power to the intermediate shaft. The intermediate shaft then drives the output shaft 301 to rotate through meshing with the output gear set 302. The output shaft 301 drives the shift wheel 501 and the coaxially fixed engagement gear ring 502 to rotate synchronously. At this time, the engagement sleeve 505 is in the neutral position, and the splined hub 504 remains relatively stationary with the output shaft 301 through the involute spline. The synchronizing ring 503 does not mesh with the engagement gear ring 502 or the splined hub 504. During this stage, the 18° spiral on the conical friction surface 6 of the engagement gear ring 502... The circumferential oil groove 901 of the corner rotates with the engagement gear ring 502, generating a "centrifugal pumping effect". On the one hand, it guides the lubricating oil in the gearbox along the spiral groove to the friction surface, forming an oil film of 0.1-0.2mm thickness, avoiding dry friction of the friction surface when idling. On the other hand, it throws out impurities such as soil particles and metal debris attached to the friction surface along the spiral direction, preventing the accumulation of impurities from causing fluctuations in the friction coefficient. This design directly solves the problems of lubrication failure and friction surface scratches in a multi-impurity environment. At the same time, the alloy steel used in the synchronization ring 503 and the gradient hardness formed by "carburizing and quenching + low temperature tempering" of the engagement gear ring 502, with the outer ring being 60HRC wear-resistant and the inner ring being 34HRC impact-resistant, lays the material foundation for subsequent high torque transmission.

[0020] When the agricultural machinery needs to shift gears, the driver operates the control lever, and the shift fork of the gear shifting mechanism pushes the engaging sleeve 505 to slide along the involute spline axis of the spline hub 504. As the engaging sleeve 505 moves, the spring rings 803 at both ends synchronously drive the locking pin 802 in the slide groove 801 of the spline hub 504 to slide in the same direction. The 16° guide slope 805 of the head of the locking pin 802 gradually contacts the inclined surface of the locking groove 804 on the end face of the synchronizing ring 503. Since the synchronizing ring 503 does not rotate with the engaging gear ring 502 at this time, the wedge-shaped fit between the locking pin 802 and the locking groove 804 is complete. The "self-locking effect" prevents the engaging sleeve 505 from getting closer to the synchronizing ring 503. This design, through a high-precision locking pair with a transition fit, avoids forced engagement when synchronization is not complete, solving the problem of tooth surface collision and tooth breakage under high-impact conditions from the source. At the same time, the preload of the spring ring 803 ensures that the locking pin 802 is always in contact with the locking groove 804. Even when the agricultural machinery is bumped and the shaft system moves slightly, there will be no loosening of the lock, further avoiding the risk of shifting impact. In addition, the spring ring 803 also avoids the impact damage to the friction surface caused by violent shifting.

[0021] As the shifting actuator continues to apply thrust, the engaging sleeve 505 overcomes the self-locking force of the locking pin 802 and pushes the synchronizing ring 503 closer to the engaging gear ring 502. The conical friction surface 6 of the synchronizing ring 503 gradually comes into contact with the conical friction surface 6 of the engaging gear ring 502. At this point, the lubricating oil film between the two friction surfaces is squeezed, and the tungsten carbide wear-resistant coating 902 on the conical friction surface 6 of the synchronizing ring 503 and the high-hardness friction surface of the engaging gear ring 502 form an efficient friction pair. Through friction, the synchronizing ring 503 is driven to rotate faster, gradually reducing the speed difference between the synchronizing ring 503 and the engaging gear ring 502. During this process, the "drum-shaped design" with a 0.1mm modification in the outer spline 701 of the synchronizing ring 503 enables the spline surface 807 and the inner spline 702 of the engaging sleeve 505 to form a progressive fit of "first contact in the middle, then full tooth contact", avoiding the off-center load caused by shaft parallelism error. The 1.4mm increased tooth root fillet reduces the tooth root stress concentration by more than 40%, and combined with the high toughness of the alloy steel, it effectively resists the risk of tooth root fracture caused by instantaneous impact load during synchronization. This series of structural designs work together to solve the problems of insufficient load-bearing capacity and poor impact resistance under high torque.

[0022] When the synchronizing ring 503 and the engaging gear ring 502 rotate in perfect synchronization, the self-locking force generated by friction disappears, the engaging sleeve 505 continues to push the synchronizing ring 503, and the guide slope 805 of the locking pin 802 head slides along the slope of the locking groove 804 to achieve automatic unlocking. At this time, the inner spline 702 of the engagement sleeve 505 precisely meshes with the outer spline 701 of the synchronizing ring 503 and the outer spline 701 of the spline hub 504. The power is transmitted via the spline path: engagement gear ring 502 → synchronizing ring 503 → engagement sleeve 505 → spline hub 504 → output shaft 301, completing the gear shift. In the subsequent power transmission process, the C-shaped compensating plate 806 on the locking pin 802 plays a role: as the locking pin 802 and the locking groove 804 develop gaps due to long-term wear, the compensating plate 806 pushes the locking pin 802 to always keep it close to the locking groove 804 through its own elastic deformation, maintaining a stable locking force and effectively avoiding the axial movement and gear skipping problems of the engagement sleeve 505 caused by wear in the traditional structure. At the same time, the drum-shaped trimmed spline surface 807 evenly distributes the large torque to each tooth surface, avoiding tooth surface peeling and pitting caused by local tooth surface overload, further extending the service life of the synchronizing assembly.

[0023] When the synchronizing ring 503 wears out due to long-term use, it is not necessary to disassemble the entire gearbox shaft system and gear set; simply open the inspection window on the housing 1, loosen the bolts connecting the upper half ring 401 and the lower half ring 402 of the synchronizing ring 503, separate the connecting block from the connecting groove, and then remove the upper and lower half rings 402 for replacement; when replacing the new synchronizing ring 503, the annular positioning steps at both ends are used to quickly align with the engaging gear ring 502 and splined hub 504, and then the bolts are tightened to complete the assembly, which greatly reduces maintenance time and cost and solves the problem of difficult maintenance of existing synchronizing devices and the impact on agricultural operations.

[0024] Throughout the entire process, the various designs form a closed loop of "material reinforcement - structural protection - dynamic adaptation - convenient maintenance"; alloy steel and wear-resistant coating 902 solve the problem of insufficient wear resistance, circumferential oil groove 901 solves the problem of impurity intrusion, wedge locking and drum-shaped trimming solve the problem of impact and off-center load, compensation plate 806 solves the problem of wear and gear skipping, and split structure solves the maintenance problem, ultimately achieving long-term reliable operation of the gearbox under complex field conditions.

[0025] The specific embodiment of the present invention has been described in detail above with reference to the accompanying drawings, but the present invention is not limited to the embodiments described above. For those skilled in the art, various changes, modifications, substitutions, and variations made to these embodiments without departing from the principles and ideas of the present invention should still fall within the protection scope of the present invention.

Claims

1. A self-propelled tracked agricultural machinery gearbox assembly, characterized in that, The system includes a housing (1), an output shaft (301), and a shift gear system (5). The output shaft (301) is rotatably connected inside the housing (1). The shift gear system (5) is mounted on the output gear set (302). The shift gear system (5) includes a shift wheel (501), a gear ring (502), a synchronizing ring (503), a splined hub (504), and a coupling sleeve (505). The shift wheel (501) is coaxially connected to the output shaft (301). The gear ring (502) is coaxially fixedly mounted on the end face of the shift wheel (501). The outer ring of the gear ring (502) and the synchronizing ring (503) are connected together. The inner ring is provided with a conical friction surface (6). The conical friction surface (6) of the synchronizing ring (503) is in clearance fit with the conical friction surface (6) of the engaging gear ring (502). The splined hub (504) is slidably connected to the output shaft (301) through an involute spline. The engaging sleeve (505) is slidably connected to the splined hub (504) on the coaxial side. The outer rings of the engaging gear ring (502), the synchronizing ring (503) and the splined hub (504) are all machined with external splines (701) of the same module and number of teeth. The inner ring of the engaging sleeve (505) is machined with an internal spline (702) that cooperates with the splined hub (504).

2. The self-propelled tracked agricultural machinery gearbox assembly according to claim 1, characterized in that: The splined hub (504) has multiple sliding grooves (801), and each of the multiple sliding grooves (801) is slidably connected with a locking pin (802). Both ends of the coupling sleeve (505) are equipped with spring rings (803), and the multiple spring rings (803) are respectively connected to the two ends of the multiple locking pins (802). The end face of the synchronizing ring (503) is evenly provided with multiple locking grooves (804) in circumferential direction, corresponding to the number of sliding grooves (801). The locking grooves (804) are adapted to the locking pins (802).

3. The self-propelled tracked agricultural machinery gearbox assembly according to claim 2, characterized in that: Each of the locking pins (802) has a compensation plate (806) installed on the side near the synchronization ring (503). The compensation plates (806) are C-shaped, and the two ends of the compensation plates (806) are respectively connected to the inner wall of the locking pin (802) and the locking groove (804).

4. The self-propelled tracked agricultural machinery gearbox assembly according to claim 3, characterized in that: The locking groove (804) and the locking pin (802) are in transition fit. The head of the locking pin (802) is provided with a 15°-20° guide slope (805). The guide slope (805) and the slope of the locking groove (804) form a wedge fit.

5. The self-propelled tracked agricultural machinery gearbox assembly according to claim 3, characterized in that: The outer spline (701) of the synchronization ring (503) is machined with a spline surface (807), which adopts a "drum-shaped trimming" design and the trimming amount of the spline surface (807) is 0.08-0.12mm.

6. The self-propelled tracked agricultural machinery gearbox assembly according to claim 1, characterized in that: The conical friction surface (6) of the engagement gear ring (502) is machined with circumferential oil grooves (901). The circumferential oil grooves (901) of the engagement gear ring (502) are distributed in a "spiral" shape, and the spiral angle is 15°-20°.

7. The self-propelled tracked agricultural machinery gearbox assembly according to claim 1, characterized in that: The synchronizing ring (503) is made of alloy steel. The conical friction surface (6) of the engaging gear ring (502) is treated with "carburizing and quenching + low temperature tempering". The hardness of the outer ring is 60-62HRC and the hardness of the inner ring is 30-35HRC.

8. The self-propelled tracked agricultural machinery gearbox assembly according to claim 7, characterized in that: The synchronization ring (503) is divided into an upper half ring (401) and a lower half ring (402), and the upper half ring (401) and the lower half ring (402) are connected to each other by bolts.

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