A tractor front axle device and a tractor

Abstract

The present application relates to tractor technical field, specifically to tractor front axle device and tractor, including axle, wheel assembly and transmission device, the transmission device includes shell, input shaft, output shaft, the transmission device further includes clutch, clutch dial, clutch yoke assembly and gear shifting gear assembly, the clutch dial is slid between the clutch and the input shaft by driving, the clutch dial and the clutch are respectively connected with the output shaft transmission, the input shaft is connected with the clutch transmission through gear shifting gear assembly, the wheel assembly is fixed with front axle connecting frame, the axle is pivoted with pull rod fixing frame for driving clutch yoke assembly, the front axle connecting frame and pull rod fixing frame are respectively connected with pull rod articulated connection, therefore, the mechanical structure is stable, the reliability is better, the transmission device is greatly simplified, is not easy to wear, is easy to maintain, and the cost is reduced.

Description

Technical Field

[0001] This invention relates to the field of tractor technology, specifically to a tractor front axle assembly and a tractor. Background Technology

[0002] Agricultural vehicles generally refer to tractors, combine harvesters, and similar equipment that operate in farmland. Many existing farmlands are small, especially paddy fields with high ridges and small plots, characterized by muddy and watery conditions and harsh working environments. This places high demands on the turning radius of agricultural vehicles. However, existing wheeled agricultural vehicles have large turning radii, making turning inconvenient and inefficient in small paddy fields or hilly areas in the south, as well as narrower farmlands in the north. Current technologies have addressed this by implementing tracked or four-wheel drive systems to reduce the turning radius, even allowing vehicles to turn on the spot. Some agricultural vehicles even use differentials to create different rotational speeds for the inner and outer wheels during turns, facilitating maneuvering. However, these methods suffer from complex structures, high costs, and difficult maintenance. For example, Chinese patent application CN106274466A discloses a tracked tractor. The tracked design reduces the turning radius. Further, CN110645285A discloses a transmission device that simplifies the structure of the tracked gearbox, facilitating the promotion of tracked agricultural vehicles, addressing the complexity of the transmission structure. However, tracked agricultural vehicles still suffer from complex transmission devices, low operating efficiency, and a narrow range of applications, making them unsuitable for wheeled agricultural vehicles. Currently, wheeled agricultural vehicles remain the primary agricultural vehicles. Regarding wheeled agricultural vehicles, Chinese patent CN208789475U discloses a new type of paddy field wheeled tractor that uses a "short wheelbase and large steering angle to achieve a minimal turning radius, facilitating turning in the field." However, this technology does not effectively solve the problem of reducing the turning radius of agricultural vehicles, nor does it improve the corresponding transmission mechanism. Chinese patent CN114670620A discloses a tractor front wheel speed-increasing steering device and steering system. The steering device increases front wheel steering to achieve rapid steering and reduce the turning radius. The steering system detects steering angle and speed, and controls a solenoid valve via a controller to enter a speed-increasing steering mode. While this prior art solves the problem of reducing the turning radius, the speed-increasing steering device has a relatively complex structure. Although switching output modes via a hydraulically driven piston is simple to operate, it places stringent requirements on sealing and other aspects, resulting in high manufacturing and maintenance costs. Furthermore, it requires sensors and a controller module, and its stability is poor in harsh working environments like tractors.

[0003] There is an urgent need for a new and simple mechanical control mechanism that can solve the problems of large turning radius, complex transmission mechanism and high operating cost of tractors in a relatively stable, convenient and low-cost way. Summary of the Invention

[0004] To address the problem of complex transmission mechanisms in existing technologies, this invention provides a tractor front axle device capable of accelerating while turning. Acceleration is controlled by mechanical linkage, resulting in high efficiency, stability, low cost, ease of maintenance, and applicability to various working environments. Furthermore, this patent also discloses a tractor with the aforementioned front axle device, which has a small turning radius, is suitable for different environments, and is cost-effective.

[0005] According to the present invention, a tractor front axle device is provided, including an axle, a wheel assembly, and a transmission device. The transmission device includes a housing, an input shaft, and an output shaft. The housing is mounted on the axle, and the output shaft outputs power to drive the wheel assembly. The transmission device further includes a clutch, a clutch dial, a clutch fork assembly, and a transmission gear assembly. The clutch dial is slidable between the clutch and the input shaft. The clutch dial and the clutch are respectively connected to the output shaft. The input shaft is connected to the clutch via the transmission gear assembly. The wheel assembly is fixed. The axle is equipped with a front axle connecting frame, on which a tie rod fixing frame for driving the clutch shift fork assembly is pivotally connected. The front axle connecting frame and the tie rod fixing frame are respectively hinged to the tie rod. When the wheel assembly rotates within a certain angle, the clutch disc is connected to the input shaft, and the power from the input shaft is output to the output shaft via the clutch disc. When the wheel assembly rotates to a certain angle, the front axle connecting frame drives the tie rod fixing frame, causing the clutch shift fork assembly to move the clutch disc. The clutch disc disengages from the input shaft and slides to engage the clutch, and the power from the input shaft is output to the output shaft via the transmission gear assembly and the clutch, thus achieving gear shifting.

[0006] Beneficial effects: The clutch dial of this invention serves as both the transmission structure for the input and output shafts and the engagement / disengagement structure for the drive clutch. Switching between normal speed and gear shifting (such as double speed) can be achieved simply by using a clutch and clutch dial. When double speed is not needed, the input and output shafts achieve direct transmission via the clutch dial, eliminating the need for gear assemblies to transmit power, resulting in no load on the gears and clutch. Therefore, this mechanical structure is stable, more reliable, greatly simplifies the transmission device, is less prone to wear, easier to maintain, and reduces costs. The control of double speed switching is achieved through a mechanical control system using a front axle connecting bracket on the wheel assembly. This control structure is simple, stable, low-cost, and easy to maintain.

[0007] Preferably, the clutch shift fork assembly includes a shift fork connecting plate, a clutch shift fork, a shift fork shaft, and a shift fork holder; the shift fork connecting plate is fixedly connected to the shift fork shaft and extends radially toward the shift fork shaft, the clutch shift fork rotates with the shift fork shaft, the shift fork holder is provided with a lever, the lever has a shift foot, the clutch disc has an annular groove, and the shift foot is inserted into the annular groove; a return tension spring and a hemispherical top rod are provided between the pull rod fixing bracket and the shift fork connecting plate; the clutch shift fork can drive the shift fork holder to rotate, and the shift foot moves the clutch disc in its axial direction.

[0008] This patent utilizes a return spring and a hemispherical push rod to achieve two methods: elastic pull-back and rigid push rod extension. These methods allow the clutch dial to make contact with the transmission on both sides in two ways. The push rod pushes the clutch dial to engage the clutch, while the spring pulls the clutch dial towards the input shaft, resulting in a smoother transmission contact and more stable clutch dial transmission.

[0009] Preferably, the clutch shift fork includes a first fork and a second fork spaced apart, and the shift fork holder is provided with a stop fork located between the first fork and the second fork; when the wheel assembly rotates within a certain angle, the stop fork is located between the first fork and the second fork; when the wheel assembly rotates beyond a certain angle, the first fork and the second fork can push the stop fork to move as the clutch shift fork rotates.

[0010] Beneficial effects: By setting the interval between the first fork and the second fork, the interval provides a certain range of free movement space for the clutch shift fork. When it exceeds this range, the first fork or the second fork drives the clutch disc. Therefore, the operation of the clutch shift fork can be controlled by mechanical design such as connecting rods, which is more stable than sensor control.

[0011] Preferably, the clutch lever includes a limiting slide cylinder and a limiting fork. The clutch lever is fixed on the limiting slide cylinder, and the limiting slide cylinder is sleeved on the fork shaft and can rotate with the fork shaft. One end of the limiting fork and the connecting plate are coaxially pivotally connected to the housing, and the other end of the driving connecting plate can rotate the limiting fork. The limiting fork moves the limiting slide cylinder to slide along the fork shaft, which can at least cause the clutch lever to disengage from the contact range with the fork.

[0012] The working conditions of the clutch shift fork can be limited or controlled by a simple limit shift fork, making it easy for the operator to choose whether to change speed. It is low in cost and has a stable control effect.

[0013] Preferably, the clutch includes a clutch gear, a transmission cover, a clutch shaft, and a clutch disc assembly. The clutch shaft is driven by the output shaft. The clutch disc assembly and the clutch dial are respectively sleeved on the clutch shaft and are driven by each other. The clutch gear is driven by the clutch disc assembly through the transmission cover. The clutch gear meshes with the transmission gear assembly. The clutch dial can slide between the input shaft and the clutch disc assembly. When the clutch dial slides to the input shaft, it is driven by the input shaft. When the clutch dial slides to engage the clutch disc assembly, it is driven by the clutch.

[0014] The shaft-to-shaft transmission connection of this invention can be understood as a spline or similar connection unless otherwise specified. The clutch dial is sleeved on the clutch shaft; on one hand, the clutch shaft serves as the transmission shaft between the clutch dial and the output shaft; on the other hand, the clutch shaft also serves as the transmission shaft between the clutch and the output shaft, reducing the need for additional transmission shafts. Furthermore, the clutch dial slides between the input shaft and the clutch plate assembly, with a small sliding range and high stability.

[0015] Preferably, the clutch plate assembly includes a plurality of alternately arranged first connecting plates and second connecting plates. The first connecting plates are connected to the transmission cover, and the second connecting plates are sleeved on the clutch shaft for transmission. The clutch dial slides and presses the clutch plate assembly so that the first connecting plates or / and the second connecting plates move and contact each other for friction transmission.

[0016] Preferably, the input shaft, the clutch shaft, and the output shaft are on the same axis. The input shaft is provided with a mating gear that meshes with the transmission gear assembly. The clutch dial and the mating gear are provided with a plurality of first mating bosses and second mating bosses at intervals in the circumferential direction. After the clutch dial moves toward the mating gear, the first mating bosses and the second mating bosses are inserted into the interval space between their respective bosses to achieve a transmission connection.

[0017] This patent describes the input shaft, clutch shaft, and output shaft as being on the same axis, which facilitates the movement of the clutch dial on the same axis and ensures structural stability. The clutch dial and the mating gear are engaged by a boss, making them easy to connect and difficult to separate, and resulting in relatively stable transmission.

[0018] Preferably, the transmission gear assembly includes a transmission shaft and a lower gear and an upper gear disposed on the transmission shaft. The lower gear meshes with a mating gear, and the upper gear meshes with a clutch gear. The transmission ratio of the mating gear × upper gear: lower gear × clutch gear is close to 2.

[0019] This patent achieves double speed by simply adding a gearbox and two gears, resulting in a simple structure and small footprint.

[0020] The present invention also provides a tractor, including a rear axle assembly, a steering wheel, and the aforementioned tractor front axle assembly.

[0021] This invention also provides a tractor, including a rear axle assembly and a steering wheel. A speed-multiplying turn control handle is disposed near the steering wheel. The control handle is connected to a connecting plate via a pull rope, and a reset component is disposed on the connecting plate. The control handle allows for the initiation of speed-multiplying turns, providing a simple operating scheme. Attached Figure Description

[0022] Figure 1 This is a cross-sectional structural diagram of the transmission device.

[0023] Figure 2 This is a schematic diagram of the transmission principle of the transmission device.

[0024] Figure 3 This is a schematic diagram of the transmission device after the housing has been removed.

[0025] Figure 4 for Figure 3 A top-down view.

[0026] Figure 5 This is a schematic diagram of the main drive (non-speed) structure of the transmission device.

[0027] Figure 6 This is a schematic diagram of the clutch dial and shift fork structure.

[0028] Figure 7 This is a schematic diagram of the shift fork structure.

[0029] Figure 8 This is a schematic diagram of the clutch structure.

[0030] Figure 9 This is a schematic diagram of the clutch plate assembly structure.

[0031] Figure 10 This is a schematic diagram of the transmission cover structure.

[0032] Figure 11 This is a schematic diagram of the axle assembly structure.

[0033] Figure 12 This is a schematic diagram of the structure of the shift fork connecting plate, return spring, and hemispherical top rod.

[0034] The image is labeled as follows:

[0035] 100-Transmission device, 101-Housing, 1-Clutch gear, 2-Clutch, 21-Transmission cover, 22-Clutch plate assembly, 221-First connecting plate, 222-Second connecting plate, 3-Clutch shaft, 4-Clutch shift fork assembly, 41-Limiting slide, 411-Arc groove, 42-Limiting shift fork, 421-Connecting plate, 43-Shift fork connecting plate, 431-Tension spring mounting hole, 432-Push rod hole, 43 3-Shaft hole, 44-Clutch shift fork, 441-First fork, 442-Second fork, 45-Shift fork shaft, 46-Shift fork holder, 461-Shift lever, 462-Shift foot, 463-Gear fork, 8-Clutch dial, 81-First mating boss, 82-Annular groove, 9-Mating gear, 91-Second mating boss, 10-Input shaft, 11-Transmission shaft, 12-Lower gear, 14-Upper gear, 15-Output shaft;

[0036] 200-Axle assembly, 201-Axle, 202-Wheel assembly, 2021-Right front wheel assembly, 2022-Left front wheel assembly, 203-Front axle connecting bracket, 204-Tie rod fixing bracket, 205-Tie rod, 206-Return tension spring, 207-Hemispherical top rod. Detailed Implementation

[0037] To further understand the content of this invention, a detailed description of the invention will be provided in conjunction with the accompanying drawings and embodiments. It should be understood that the embodiments are merely illustrative and not limiting of the invention.

[0038] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "clockwise," and "counterclockwise," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.

[0039] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, unless otherwise stated, "a plurality of" means two or more, unless explicitly defined otherwise.

[0040] In this invention, unless otherwise explicitly specified and limited, the terms "installation," "connection," "linking," and "fixing," etc., should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0041] like Figure 1-12 As shown, the present invention also provides a tractor axle assembly 200, which includes an axle 201, a wheel assembly 202 mounted on the axle 201, and a transmission device 100. The wheel assembly 202 includes a right front wheel assembly 2021 and a left front wheel assembly 2022, which are respectively mounted on the left and right ends of the axle 201. The transmission device 100 is mounted on the middle section of the axle 201.

[0042] like Figure 1-10 As shown, the transmission device 100 can be described as a clutch transmission device, including a housing 101, an input shaft 10 with coincident axes, a clutch 2, and an output shaft 15, and also includes a gear shift shaft 11, the axis of which is parallel to the axis of the clutch 2. The clutch 2 includes a clutch shaft 3 and a clutch gear 1, the clutch shaft 3 being drive-connected to the output shaft 15. This drive-connection includes gear drive connection, fixed connection, sleeve drive, etc. In this embodiment, one end of the output shaft 15 is provided with an external spline, and the clutch shaft 3 has a through hole with an internal spline. One end of the output shaft 15 is inserted into the through hole of the clutch shaft 3, and the spline and spline groove cooperate for transmission. Alternatively, the output shaft 15 can be provided with an internal spline, while the clutch shaft 3 can be provided with an external spline.

[0043] like Figure 3 As shown, a mating gear 9 is mounted on one end of the input shaft 10, which meshes with a lower gear 12 for transmission. The lower gear 12 is mounted on one end of the transmission shaft 11, and an upper gear 14 is mounted on the other end of the transmission shaft 11, meshing with a clutch gear 1 for transmission. The clutch gear 1 is sleeved on the clutch shaft 3 and can rotate relative to the clutch shaft 3. Between the clutch gear 1 and the mating gear 9, a clutch dial 8 is mounted on the clutch shaft 3. The clutch dial 8 can slide left and right on the clutch shaft 3 and can transmit power. A common method is to connect them via a spline connection. When the clutch dial 8 is moved to the right, it can be connected to the mating gear 9 on its right side for transmission at normal speed. When the clutch dial 8 is moved to the left, it is connected to the clutch gear 1 on its left side. By adjusting the speed of the upper gear 14 and the lower gear 12, transmission at different speeds can be achieved.

[0044] To achieve double-speed transmission, one implementation method is to use a 22T gear for the connecting gear 9, a 15T gear for the lower gear 12, a 22T gear for the upper gear 14, and a 16T gear for the clutch gear 1. The transmission ratio of the two pairs of gears is 22 x 22 : 15 x 16 ≈ 2.017, meaning that the output speed of the clutch shaft is approximately twice the input speed of the input shaft, thus achieving double-speed transmission.

[0045] like Figures 4-6 As shown, the right side of the clutch disc 8 is provided with a plurality of first mating bosses 81 spaced apart along the circumferential direction, and the left side of the mating gear 9 is provided with a plurality of second mating bosses 91 spaced apart along the circumferential direction. That is, the clutch disc 8 and the mating gear 9 are respectively provided with mating bosses on opposite sides. After the clutch disc 8 is moved toward the mating gear 9, the first mating bosses 81 and the second mating bosses 91 can cooperate with each other, inserting into the space between their respective bosses, forming abutments between the sides of the first mating bosses 81 and the second mating bosses 91, thus realizing the transmission connection between the clutch disc 8 and the mating gear 9, and also facilitating their separation. The bosses described in this patent include protrusions relative to the plane of the structural body, as well as planar portions relative to the grooves.

[0046] A clutch transmission assembly 2 is provided between the clutch dial 8 and the clutch gear 1. When the clutch dial 8 is moved to the left and abuts against the clutch transmission assembly 2, the clutch transmission assembly 2 is connected to the clutch shaft 3 for transmission, so that the clutch gear 1 is connected to the clutch shaft 3 for transmission through the clutch transmission assembly 2.

[0047] The clutch 2 includes a clutch shaft 3, a clutch gear 1, a transmission cover 21, and a clutch plate assembly 22. The transmission cover 21 is circular with an edge extending towards the clutch plate assembly 22. The transmission cover 21 is fixedly connected to the clutch gear 1, and rotational transmission is achieved through methods such as interference fit, welding, or splines. Simultaneously, the transmission cover 21 is connected to the clutch plate assembly 21, and the clutch plate assembly 21 is connected to the clutch shaft 3. The clutch plate assembly 22 includes several first connecting plates 221 and second connecting plates 222, which are alternately arranged. The first connecting plates 221 are connected to the transmission cover 21, and the second connecting plates 222 are connected to the clutch shaft 3. When the clutch disc 8 is moved to the left and comes into contact with the clutch plate assembly 22, the first connecting plates 221 and second connecting plates 222 are pressed together under the force of the clutch disc 8, achieving a transmission connection. The first connecting plates 221 and second connecting plates 222 are friction plates. The clutch plate assembly 22 operates when pressed together and disengages when disengaged. Due to dimensional tolerances in the components, there is an overall error after assembly. Therefore, in the design of the reference dimensions, a 0.5mm gap is left between the clutch dial 8 disengaging from the transmission of the engaging gear 9 and the complete engagement of the clutch plate assembly 22. The small gap in neutral means that although the clutch transmission plate assembly is not fully engaged, it can still provide a certain amount of friction, preventing a complete loss of power. Moreover, the 0.5mm gap can be eliminated by simply turning the steering wheel 1-2 degrees, without affecting actual use.

[0048] To enable the left and right movement of the clutch dial 8, a clutch shift fork assembly 4 is provided. The clutch shift fork assembly 4 includes a shift fork holder 46, a shift fork shaft 45, a clutch shift fork 44, a shift fork connecting plate 43, a limiting shift fork 42, and a limiting slide cylinder 41. The shift fork holder 46 is provided with mounting holes and can be rotatably fitted onto the shift fork shaft 45. The axis of the shift fork shaft 45 is the axis of rotation of the shift fork holder 46. Of course, the mounting method of the shift fork holder 46 is not limited; it can also be provided with a mounting shaft and rotatably mounted on the housing or base of the transmission device. The shift fork holder 46 is provided with a lever 461, and a lever foot 462 is provided at the extended end of the lever 461. The rotation of the shift fork holder 46 drives the lever 461 to rotate, and the arc-shaped movement of the lever foot 462 can form a left-right movement or a forward-backward movement path.

[0049] The clutch disc 8 has an annular groove 82, which is a circular groove on the circumference of the clutch disc 8. The shift foot 462 is inserted into the annular groove 82, and then the shift foot 462 cooperates with the clutch disc 8, driving the clutch disc 8 to move left and right. The shift fork 46 is C-shaped and has two shift levers 461 and two corresponding shift feet 462, which are located on both sides of the clutch disc 8.

[0050] The clutch shift fork 44 rotates synchronously with the shift fork shaft 45, and the shift fork connecting plate 43 drives the shift fork shaft 45 to rotate. The clutch shift fork 44 includes a first fork 441 and a second fork 442, with a space between the first fork 441 and the second fork 442, which is the idle stroke of the clutch shift fork 44. A stop fork 463 is provided on the shift fork holder 46, and the first fork 441 and the second fork 442 respectively abut against the stop fork 463, causing the shift fork holder 46 to rotate forward and reverse. To save space and make the clutch shift fork 44 more efficient, the stop fork 463 is located outside a lever 461, that is, on the side away from the shift foot 462. The shift foot 462 is cylindrical or rectangular, etc. When the shift foot 462 is rectangular, it can rotate relative to the lever 461.

[0051] The clutch shift fork 44 can slide up and down on the shift fork shaft 45, including direct or indirect connection. In one embodiment, a limiting slide cylinder 41 is sleeved on the shift fork shaft 45. The limiting slide cylinder 41 can slide up and down on the shift fork shaft 45 and rotates synchronously with the shift fork shaft 45. The clutch shift fork 44 is welded to the limiting slide cylinder 41. The sliding connection between the limiting slide cylinder 41 and the shift fork shaft 45 includes non-circular surface connections, such as spline fit, two-plane fit, or fit with a groove through a plug or protrusion.

[0052] The limiting fork 42 moves the limiting slide cylinder 41 up and down on the fork shaft 45. An arc-shaped groove 411 is provided on the limiting slide cylinder 41, and one end or part of the limiting fork 42 is located within the arc-shaped groove 411. The curvature of the arc-shaped groove 411 ensures that the limiting fork 42 can cooperate with the arc-shaped groove 411 within the rotation range of the fork shaft 45. For ease of installation and manufacturing, the curvature of the arc-shaped groove 411 can be a circular arc. The limiting fork 42 is provided with a connecting plate 421, which is pivotally connected to the housing 101 and connected to the control handle via a rope or connecting rod. Whether or not a return spring, limiting stop, etc., are included is determined by those skilled in the art based on actual needs and specific applications. In one specific embodiment, the control handle has a limiting and return torsion spring.

[0053] like Figure 2As shown, the working principle of the clutch transmission device of the present invention is as follows: During normal operation, the clutch disc 8 is connected to the engaging gear 9, and power is input from the input shaft 10, passing sequentially through the engaging gear 9, the clutch disc 8, and the clutch shaft 3 to the output shaft 15. When the clutch disc 8 is engaged against the clutch transmission assembly 2, power is input from the input shaft 10, passing sequentially through the engaging gear 9, the lower gear 12, the transmission shaft 11, the upper gear 14, the clutch gear 1, the clutch transmission assembly 2, and the clutch shaft 3 to the output shaft 15. The output speed is adjusted by adjusting the transmission ratios of the engaging gear 9: lower gear 12 and the upper gear 14: clutch gear 1. For example, if the transmission ratio of the two pairs of gears is 22 x 22: 15 x 16 ≈ 2.017, the output speed of the clutch shaft is approximately twice the input speed of the input shaft, which is a double-speed transmission mode. The movement of the clutch disc 8 is adjusted by the clutch fork assembly 4, and the clutch fork 42 limits whether the clutch fork 44 can engage the clutch disc 8.

[0054] A front axle connecting bracket 203 is installed on either the left front wheel assembly 2022 or the right front wheel assembly 2021. The front axle connecting bracket 203 can swing with the front wheel. A tie rod fixing bracket 204 is hinged to the axle 201. The front axle connecting bracket 203 is connected to the tie rod fixing bracket 204 via a tie rod 205. The tie rod fixing bracket 204 is connected to the shift fork connecting plate 43. When the steering wheel is turned half a turn to the left or right, the tire swings approximately 20° to the left or right. The front axle connecting bracket 203 on the wheel assembly 202 pulls the tie rod fixing bracket 204 to rotate clockwise, driving the shift fork connecting plate 43, which in turn drives the shift fork shaft 45 to rotate, and the transmission device 100 switches to a double-speed transmission mode. The connection between the tie rod fixing bracket 204 and the shift fork connecting plate 43 includes a return spring 206 and a hemispherical top rod 207.

[0055] like Figure 11-12The shift fork connecting plate 43 has a tension spring mounting hole 431, a push rod hole 432, and a shaft hole 433. The pull rod mounting bracket 204 has two ball heads; one connects to the front axle connecting bracket 203 via a pull rod 205, and the other is equipped with a hemispherical push rod 207 (partially obscured by a return spring 206). The head of the hemispherical push rod 207 passes through the hemispherical push rod hole 432 of the shift fork connecting plate 43, with the hemispherical portion abutting against the circular hole. One end of the return spring 206 is hung on the pull rod mounting bracket 207, and the other end is hung on the tension spring mounting hole 431. The shift rod shaft 45 is inserted into the shaft hole 433 and engages with it, with the shift fork connecting plate 43 extending radially toward the shift rod shaft 45. Driven by the swinging motion of the front axle connecting bracket 203, the pull rod 205 pulls the pull rod mounting bracket 204 to rotate clockwise around the hinge axis. The return spring 206 controls the forward pull, and the hemispherical push rod 207 controls the backward push. The clutch is pushed back to engage with the clutch cover plate 8, and pulled forward to engage one side of the clutch cover plate 8 with the mating gear 9. The push and pull of the return spring 206 and the hemispherical rod 207 on the shift fork connecting plate 43 cause the shift fork shaft 45 to rotate, which in turn drives the clutch shift fork 44 to rotate. After the clutch shift fork 44 rotates to a certain angle, it drives the shift fork holder 46 to rotate, which in turn drives the clutch dial 8 to work.

[0056] The present invention also includes a tractor (not shown in the accompanying drawings), comprising an axle assembly 200 and a steering wheel (not shown in the accompanying drawings). A speed-doubled turning control handle (not shown in the accompanying drawings) is provided near the steering wheel. The control handle is connected to a connecting plate 421 via a pull rope. A reset component, such as a reset spring, is provided on the connecting plate 421. The transmission device 100 uses a gear ratio of 9 x upper gear 14: lower gear 12 x clutch gear 1 with a ratio close to 2, specifically, the gear ratio of the two pairs of gears is 22 x 22: 15 x 16 ≈ 2.017. Moving the control handle causes the limit fork 42 to push the limit slide 41 downwards, and the clutch fork 44 engages with the clutch dial 8. When the steering wheel is turned more than half a turn, the speed-doubled turning begins, doubling the speed of the front wheels to achieve speed-doubled turning.

[0057] By controlling the shift fork switch, tractors, such as motor tractors, can turn or make a U-turn with a smaller turning radius (about half that of a normal turn) when they need to turn or make a U-turn on narrower roads, thereby improving the tractor's adaptability to different working environments.

[0058] The working principle of limiting speed during turns:

[0059] When the clutch shift fork 44 is closed, one method is to operate the limit shift fork 42 by operating the control handle to disengage the clutch shift fork 44 from the clutch dial 8, and the engagement gear 9 remains engaged with the clutch dial 8. The input speed of the front axle input shaft 10 is the same as the output speed of the clutch shaft, and there is no speed-multiplying turning.

[0060] After the clutch fork 44 is opened, the limit fork 42 pushes the clutch fork 44 to connect it with the clutch disc 8. When the front wheel rotates to a certain angle, the clutch fork 44 controls the clutch disc 8 to disengage from the engagement gear. The power input from the front axle input shaft is transmitted to the clutch gear 1 through the upper and lower gears of the speed-doubling steering mechanism. As the clutch disc 8 is pulled up, the clutch plate assembly 22 is pressed, and the clutch gear can drive the clutch shaft through the clutch to output power. The transmission device 100 uses a gear ratio of engagement gear 9 x upper gear 14: lower gear 12 x clutch gear 1 that is close to 2. Specifically, the gear ratio of the two pairs of gears is 22 x 22: 15 x 16 ≈ 2.017, that is, the output speed of the clutch shaft is about twice the input speed of the front axle input shaft, and the front wheel speed is doubled to achieve speed-doubling steering.

[0061] The present invention and its embodiments have been described above illustratively. This description is not restrictive, and the figures shown are only one embodiment of the present invention; the actual structure is not limited thereto. Therefore, if those skilled in the art are inspired by this description and design similar structures and embodiments without departing from the spirit of the invention, such designs should fall within the protection scope of the present invention.

Claims

1. A tractor front axle assembly, comprising an axle (201), a wheel assembly (202), and a transmission device (100), wherein the transmission device (100) includes a housing (101), an input shaft (10), and an output shaft (15), the housing (101) being mounted on the axle (201), and the output shaft (15) outputting power to drive the wheel assembly (202); characterized in that, The transmission device (100) further includes a clutch (2), a clutch dial (8), a clutch fork assembly, and a transmission gear assembly; the clutch dial (8) is moved to slide between the clutch (2) and the input shaft (10), the clutch dial (8) and the clutch (2) are respectively connected to the output shaft (15), and the input shaft (10) is connected to the clutch (2) via the transmission gear assembly; the wheel assembly (202) is fixed with a front axle connecting frame (203), and the axle (201) is pivotally connected with a tie rod fixing frame (204) for driving the clutch fork assembly, the front axle connecting frame (203) and the tie rod fixing frame (204) is hinged to the tie rod (205); when the wheel assembly (202) rotates within a certain angle, the clutch dial (8) is connected to the input shaft (10) for transmission, and the power of the input shaft (10) is output to the output shaft (15) through the clutch dial (8); when the wheel assembly (202) rotates to a certain angle, the front axle connecting frame (203) drives the tie rod fixing frame (204) to cause the clutch fork assembly to move the clutch dial (8), and the clutch dial (8) disengages from the input shaft (10) and slides to the engagement clutch (2) for transmission. The power of the input shaft (10) is output to the output shaft (15) through the transmission gear assembly and the clutch (2) to realize speed change; The clutch (2) includes a clutch gear (1), a transmission cover (21), a clutch shaft (3), and a clutch plate assembly (22). The clutch shaft (3) is connected to the output shaft (15). The clutch plate assembly (22) and the clutch dial (8) are respectively mounted on the clutch shaft (3) and are connected to each other. The clutch gear (1) is connected to the clutch plate assembly (22) through the transmission cover (21). The clutch gear (1) meshes with the transmission gear assembly. The clutch dial (8) can slide between the input shaft (10) and the clutch plate assembly (22). When the clutch dial (8) slides to the input shaft (10), it is connected to the input shaft (10). The clutch dial (8) slides to engage the clutch plate assembly (22) for transmission.

2. The tractor front axle assembly according to claim 1, characterized in that, The clutch shift fork assembly includes a shift fork connecting plate (43), a clutch shift fork (44), a shift fork shaft (45), and a shift fork holder (46). The shift fork connecting plate (43) is fixedly connected to the shift fork shaft (45) and extends radially toward the shift fork shaft (45). The clutch shift fork (44) rotates with the shift fork shaft (45). The shift fork holder (46) is provided with a lever (461). The lever (461) has a lever foot (462). The clutch disc (8) has an annular groove (82). The lever foot (462) is inserted into the annular groove (82). A return spring (206) and a hemispherical top rod (207) are provided between the pull rod fixing bracket (204) and the shift fork connecting plate (43). The clutch shift fork (44) can drive the shift fork holder (46) to rotate. The lever foot (462) moves the clutch disc (8) in its axial direction.

3. The tractor front axle assembly according to claim 2, characterized in that, The clutch shift fork (44) includes a first fork (441) and a second fork (442) spaced apart. The shift fork holder (46) is provided with a stop fork (463), which is located between the first fork (441) and the second fork (442). When the wheel assembly (202) rotates within a certain angle, the stop fork (463) is located between the first fork (441) and the second fork (442). When the wheel assembly (202) rotates beyond a certain angle, the first fork (441) and the second fork (442) can push the stop fork (463) to move as the clutch shift fork (44) rotates.

4. The tractor front axle device according to claim 3, characterized in that, The device includes a limiting slide (41) and a limiting shift fork (42). The clutch shift fork (44) is fixed on the limiting slide (41). The limiting slide (41) is sleeved on the shift fork shaft (45) and can rotate with the shift fork shaft (45). One end of the limiting shift fork (42) and the connecting plate (421) are coaxially pivotally connected to the housing (101), and the other end of the driving connecting plate (421) can rotate the limiting shift fork (42). The limiting shift fork (42) moves the limiting slide (41) to slide along the shift fork shaft (45) to at least cause the clutch shift fork (44) to disengage from the contact range with the shift fork (463).

5. The tractor front axle assembly according to claim 1, characterized in that, The clutch plate assembly (22) includes several alternately arranged first connecting plates (221) and second connecting plates (222). The first connecting plate (221) is connected to the transmission cover (21) and the second connecting plate (222) is sleeved on the clutch shaft (3) for transmission connection. The clutch dial (8) slides and presses the clutch plate assembly (22), causing the first connecting plate (221) or / and the second connecting plate (222) to move and contact friction transmission.

6. The tractor front axle assembly according to claim 1, characterized in that, The input shaft (10), the clutch shaft (3), and the output shaft (15) are on the same axis. The input shaft (10) is provided with a mating gear (9) that meshes with the transmission gear assembly. The clutch dial (8) and the mating gear (9) are provided with a plurality of first mating bosses (81) and second mating bosses (91) spaced apart in the circumferential direction. After the clutch dial (8) moves toward the mating gear (9), the first mating bosses (81) and the second mating bosses (91) are inserted into the space between their respective bosses to achieve transmission connection.

7. The tractor front axle assembly according to claim 6, characterized in that, The gear assembly includes a gear shaft (11) and a lower gear (12) and an upper gear (14) disposed on the gear shaft (11). The lower gear (12) meshes with a mating gear (9), and the upper gear (14) meshes with a clutch gear (1). The transmission ratio of mating gear (9) x upper gear (14) : lower gear (12) x clutch gear (1) is close to 2.

8. A tractor, comprising a rear axle assembly and a steering wheel, characterized in that, Includes the tractor front axle assembly as described in any one of claims 1-7.

9. A tractor, comprising a rear axle assembly and a steering wheel, characterized in that, The tractor front axle device as described in claim 4 includes a speed-double turning control handle near the steering wheel, the control handle being connected to a connecting plate (421) via a pull rope, and a reset component being provided on the connecting plate (421).

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