A steering mechanism for a three-wheeled tractor

Abstract

The utility model relates to the technical field of agricultural machinery, especially a steering mechanism of three-wheel tractor. Including front wheel, front wheel is installed on the front wheel fork support, and the upper end of front wheel fork support is fixedly connected with the front wheel main shaft that sets up longitudinally, and the front wheel main shaft is connected with the front axle bracket through the bearing, and the front axle bracket includes the bracket bottom plate with main shaft mounting hole, and the gasket plate fixedly connected on the upper surface of bracket bottom plate, the lower end of front wheel main shaft is fixedly connected on the front wheel fork support through the main shaft flange, and the middle section of front wheel main shaft is equipped with the front wheel axle sleeve through the thrust centripetal bearing, and the outer wall of front wheel axle sleeve is provided with the axle sleeve flange for connecting the bracket bottom plate, and the top of front wheel main shaft is fixedly connected with the direction turntable, and the edge of direction turntable is provided with the steering oil cylinder between gasket plate. The steering mechanism front wheel main shaft is connected through the thrust centripetal bearing between the front axle bracket, can bear certain axial pressure also can bear greater radial impact force, and its structure is compact and reasonable, and the impact resistance is strong, and the production and maintenance are convenient.

Description

Technical Field

[0001] This utility model relates to the technical field of agricultural machinery, and in particular to a steering mechanism for a three-wheeled tractor. Background Technology

[0002] Tractor steering methods can be categorized into three types based on technological differences: mechanical, hydraulically assisted, and fully hydraulic. Mechanical steering mechanisms convert rotational motion into steering arm swing by the driver turning the steering wheel, which in turn drives the steering gear (either a worm gear or a recirculating ball type). This swing is transmitted via a tie rod to the steering knuckle, driving the wheels to turn. Mechanical steering mechanisms are simple in structure and low in cost, but they suffer from high steering resistance and require considerable effort to operate, and have been gradually phased out. Hydraulically assisted and fully hydraulic steering mechanisms use an engine-driven hydraulic pump to transmit oil pressure to the steering control valve. Steering wheel movements adjust the hydraulic oil flow, pushing the power steering cylinder to assist steering. However, existing hydraulically assisted steering mechanisms all employ a trapezoidal steering mechanism, which is activated by a steering tie rod to synchronize the two steering wheels, thus driving the tractor to turn. This steering mechanism is only suitable for four-wheeled tractors and not for single-steering-wheel structures. Chinese Patent 2009100354289 discloses a "Steering Mechanism for a Three-Wheeled Tractor," authorized publication number CN101670849B. The steering mechanism includes a steering wheel, a frame, a thrust bearing, steering cylinders, and a U-shaped fork. The thrust bearing includes a bearing housing, a drive disc located on the upper part of the bearing housing, a driven disc located on the lower part, and balls. The lower part of the U-shaped fork is connected to the steering wheel, and the upper part is connected to the driven disc with raceways. The frame is connected to the bearing housing, and the bearing housing has a radial shoulder located between the upper and lower raceways. The balls are respectively installed between the raceways of the drive disc and the upper raceway of the bearing housing, and between the lower raceway of the bearing housing and the raceway of the driven disc. The drive disc and the driven disc are connected by fasteners, and an adjusting shim is provided between the drive disc and the driven disc. Two steering cylinders are symmetrically arranged on both sides of the longitudinal center of the tractor. One end of the steering cylinder is hinged to the frame, and the other end is hinged to the drive disc. The front and rear oil chambers of the two steering cylinders are connected in series by hydraulic oil pipes. The thrust bearing used in this mechanism is a non-standard part, which has high production costs and weak radial load capacity. When the steering wheel is subjected to a large horizontal impact force, the thrust bearing is easily damaged or even disintegrated. Utility Model Content

[0003] The purpose of this invention is to provide a three-wheeled tractor steering mechanism that is compact in structure and has strong impact resistance.

[0004] To achieve the above objectives, this utility model provides the following technical solution: The present invention discloses a steering mechanism for a three-wheeled tractor, comprising a front wheel mounted on the central axis of the tractor's front end, the front wheel being mounted on a front wheel fork, a longitudinally arranged front wheel spindle fixedly connected to the upper end of the front wheel fork, a front axle bracket connected to the front wheel spindle via bearings, the front axle bracket including a bracket base plate with spindle mounting holes and a pad fixedly connected to the upper surface of the bracket base plate; the lower end of the front wheel spindle fixedly connected to the front wheel fork via a spindle flange; a front wheel bushing fitted in the middle section of the front wheel spindle via a thrust radial bearing, the outer wall of the front wheel bushing having a bushing flange for connecting to the bracket base plate; a steering wheel fixedly connected to the top end of the front wheel spindle, a steering cylinder being disposed between the edge of the steering wheel and the pad.

[0005] With this design, the steering mechanism's front wheel spindle is connected to the front axle bracket via a thrust radial bearing, which can withstand both axial pressure and large radial impact force. It has a compact structure and strong impact resistance.

[0006] Preferably, the front wheel fork includes a left fork plate and a right fork plate arranged parallel to each other, and a connecting plate fixedly connected to the upper end of the left fork plate and the right fork plate. A limiting hole is provided in the middle of the connecting plate, and a limiting block adapted to the limiting hole is provided at the lower end of the front wheel spindle. The limiting block is installed in the limiting hole.

[0007] With this solution, the front wheel spindle and the front wheel fork adopt a separate assembly structure, which helps to reduce production costs and facilitate maintenance. The fit between the limit block and the limit hole helps to improve the connection strength.

[0008] Preferably, the steering wheel has a spindle mounting hole at its center, and cylinder connection holes are symmetrically arranged on both sides of the spindle mounting hole; a spindle connecting post is provided at the top of the front wheel spindle, the spindle connecting post is installed in the spindle mounting hole of the steering wheel, a cover plate is fixedly connected to the upper surface of the steering wheel covering the spindle mounting hole, a center bolt connected to the spindle connecting post is provided at the center of the cover plate, and multiple peripheral bolts connected to the steering wheel are arranged around the center bolt on the edge of the cover plate.

[0009] With this solution, there is a steering cylinder on each side of the steering wheel, making steering movements flexible and smooth.

[0010] Preferably, the upper end of the front wheel axle sleeve is fixedly connected to an upper bearing cover, and the lower end is fixedly connected to a lower bearing cover. Both the upper and lower bearing covers are annular structures that are fixedly connected to the end face of the front wheel axle sleeve by bolts, and the inner annular surfaces of the upper and lower bearing covers are clearance-fitted with the front wheel spindle.

[0011] This solution improves the sealing performance of the thrust radial bearing and extends its service life. The technical effects and advantages of this invention are as follows: The steering mechanism's front wheel spindle is connected to the front axle bracket via a thrust radial bearing, which can withstand both axial pressure and significant radial impact. Its structure is compact and reasonable, with strong impact resistance, and it is convenient for production and maintenance. Attached Figure Description

[0012] Figure 1 This is a three-dimensional structural schematic diagram of one embodiment of the present invention.

[0013] Figure 2 This is a partial cross-sectional view of the front wheel fork and the front wheel spindle.

[0014] Figure 3 This is a three-dimensional structural diagram of the front axle bracket.

[0015] Figure 4 This is a three-dimensional structural diagram of the front wheel fork.

[0016] Figure 5 This is a 3D structural diagram of the steering wheel.

[0017] Figure 6 This is a three-dimensional structural diagram of the front wheel spindle. Figure 7 This is a three-dimensional structural schematic diagram of another embodiment of the present invention. Detailed Implementation

[0018] To further illustrate the technical means and effects of the present invention in achieving its intended purpose, the following detailed description of the specific implementation methods, structures, features, and effects of the present invention, in conjunction with the accompanying drawings and preferred embodiments, is provided.

[0019] like Figure 1 , Figure 2 As shown, the steering mechanism of the three-wheeled tractor of this utility model includes a front wheel 1 mounted on the central axis of the tractor's front end. The front wheel 1 is mounted on a front wheel fork 2, and a diesel engine is mounted behind the front wheel fork 2 to provide power for walking and agricultural operations. A longitudinally arranged front wheel spindle 21 is fixedly connected to the upper end of the front wheel fork 2. Figure 4As shown, the front wheel fork 2 includes a left fork plate 22 and a right fork plate 23 arranged parallel to each other, and a connecting plate 24 fixedly connected to the upper ends of the left fork plate 22 and the right fork plate 23. The front wheel 1 is rotatably mounted on the lower ends of the left fork plate 22 and the right fork plate 23 via an axle. A limiting hole 25 is provided in the middle of the connecting plate 24. The lower end of the front wheel spindle 21 has a limiting block 26 adapted to the limiting hole 25, and the limiting block 26 is installed in the limiting hole 25. The lower end of the front wheel spindle 21 has a spindle flange. When the limiting block 26 is installed in the limiting hole 25, the spindle flange presses against the upper surface of the connecting plate 24, and the spindle flange is fixedly connected to the connecting plate 24 by bolts. Of course, the spindle flange and the connecting plate 24 can also be welded together or connected by rivets.

[0020] The front wheel spindle 21 is connected to the front axle bracket 4 via bearings, allowing the front wheel spindle 21 to rotate relative to the front axle bracket 4, thereby achieving front wheel steering.

[0021] like Figure 3 As shown, the front axle bracket 4 includes a bracket base plate 42 with a spindle mounting hole 41 and a pad 43 fixedly connected to the upper surface of the bracket base plate 42. The bracket base plate 42 is a rectangular flat plate structure, and the pad 43 is a gantry structure welded to the front end of the bracket base plate 42, so that the upper surface of the pad 43 is slightly higher than the bracket base plate 42. In addition, in order to improve the overall structural strength of the front axle bracket 4 and facilitate the installation of accessories such as radiators and engine hoods, etc. Figure 7 As shown, side wall panels 44 can also be welded around the bracket base plate 42, and an upper cover plate 45 is fixedly connected to the upper end of the wall panels 44. A radiator base 46 is then connected to the upper cover plate 45. The side wall panels 44 are arranged around the bracket base plate 42, forming a stable rectangular frame structure together with the upper cover plate 45. The upper cover plate 45 covers the pad plate 43, and its width on both sides is slightly larger than that of the bracket base plate 42, facilitating the installation of the machine cover. The radiator base 46 is a gantry structure fixedly connected to the upper cover plate 45, facilitating the installation and removal of the radiator.

[0022] like Figure 2 , Figure 6As shown, the lower end of the front wheel spindle 21 is fixedly connected to the front wheel fork 2 via a spindle flange 27. The middle section of the front wheel spindle 21 is fitted with a front wheel axle sleeve 6 via a thrust radial bearing 5. This thrust radial bearing 5 can be a single bearing or two bearings used side-by-side. The outer wall of the front wheel axle sleeve 6 is provided with a sleeve flange for connecting to the bracket base plate 42. The diameter of the spindle mounting hole 41 on the bracket base plate 42 is slightly larger than the diameter of the front wheel spindle 21 but smaller than the diameter of the sleeve flange. After the thrust radial bearing 5 and the front wheel axle sleeve 6 are installed on the front wheel spindle 21, they are inserted into the spindle mounting hole 41. At this time, the edge of the sleeve flange presses against the upper surface of the bracket base plate 42, and the sleeve flange is fixedly connected to the bracket base plate 42 using bolts. Thanks to the action of the thrust radial bearing 5, after installation, the front wheel spindle 21 can rotate within the thrust radial bearing 5, that is, rotate relative to the front axle bracket 4.

[0023] like Figure 1 As shown, a steering wheel 7 is fixedly connected to the top of the front wheel spindle 21. A steering cylinder 8 is provided between the edge of the steering wheel 7 and the pad 43. The front end of the steering cylinder 8 is hinged to the pad 43 via a front connecting post, and the rear end is hinged to the edge of the steering wheel 7 via a rear connecting post. When the steering cylinder 8 extends or retracts, it can push the steering wheel 7 to deflect. Figure 5 As shown, the steering wheel 7 has a spindle mounting hole 71 at its center, and cylinder connection holes 72 are symmetrically arranged on both sides of the spindle mounting hole 71. These cylinder connection holes 72 are used to install rear-end connecting columns. The lower end of the rear-end connecting column is fixedly installed in the cylinder connection hole 72, and the upper end is inserted into the hinge hole of the steering cylinder 8. Two steering cylinders 8 are symmetrically arranged on both sides of the spindle mounting hole 71. During steering, one cylinder applies a thrust, and the other cylinder applies a pull. The two cylinders work together to deflect the steering wheel 7 around the central axis of the spindle mounting hole 71. The steering cylinders 8 are connected to a hydraulic system, including a hydraulic pump, via hoses and hydraulic control valves. The structure, principle, and wiring connection of the hydraulic system are well-known technologies and will not be detailed here.

[0024] A main shaft connecting post 211 is provided at the top of the front wheel main shaft 21, and the main shaft connecting post 211 is installed in the main shaft mounting hole 71 of the steering wheel 7. To prevent the main shaft connecting post 211 from rotating relative to the steering wheel 7, such as... Figure 5 , Figure 6 As shown, keyways are provided at corresponding positions on the spindle mounting hole 71 and the spindle connecting post 211. After the spindle connecting post 211 is installed into the spindle mounting hole 71, a flat key can be inserted into the keyway to lock the position of the spindle connecting post 211 and the direction dial 7, preventing the direction dial 7 from becoming loose.

[0025] In addition, such as Figure 2As shown, a cover plate 721 is fixedly connected to the upper surface of the steering wheel 7, covering the spindle mounting hole 71. A central bolt connected to the spindle connecting column 211 is provided at the center of the cover plate 721, and multiple peripheral bolts connected to the steering wheel 7 are provided around the central bolt at the edge of the cover plate 721. The central bolt is fixedly connected to the central axis of the spindle connecting column 211, serving as a central positioning element, while the peripheral bolts pass through and connect the cover plate 721 and the steering wheel 7, serving to fix the position of the steering wheel 7.

[0026] Furthermore, as a further improvement of this utility model, the upper end of the front wheel axle sleeve 6 is fixedly connected to a bearing upper end cover 61, and the lower end is fixedly connected to a bearing lower end cover 62. Both the bearing upper end cover 61 and the bearing lower end cover 62 are annular structures fixedly connected to the end face of the front wheel axle sleeve 6 by bolts. The inner annular surfaces of the bearing upper end cover 61 and the bearing lower end cover 62 are clearance-fitted with the front wheel main shaft 21. In this way, the bearing upper end cover 61 and the bearing lower end cover 62 respectively cover the upper and lower end faces of the thrust radial bearing 5, playing a role in sealing and dust prevention. Of course, a sealing ring can also be installed in the gap between the inner annular surface of the bearing upper end cover 61 or the bearing lower end cover 62 and the front wheel main shaft 21 to further improve the sealing effect without affecting the rotation of the front wheel main shaft 21.

[0027] In use, turning the steering wheel activates the steering gear control hydraulic system, which drives the steering cylinder 8. One cylinder on one side of the steering wheel 7 extends, pushing the steering wheel 7 to deflect, while the other cylinder retracts, pulling the steering wheel 7 to deflect. The two cylinders work together to deflect the steering wheel 7, causing the front wheel spindle 21, front wheel fork 2, and front wheels to deflect, thus achieving steering. The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention in any way. Although the present invention has been disclosed above with reference to preferred embodiments, it is not intended to limit the invention. Any person skilled in the art can make some modifications or alterations to the above-disclosed technical content to create equivalent embodiments without departing from the scope of the present invention. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of the present invention without departing from the scope of the present invention are still within the scope of the present invention.

Claims

1. A steering mechanism for a three-wheeled tractor, comprising a front wheel (1) mounted on the central axis of the front end of the tractor, the front wheel (1) being mounted on a front wheel fork (2), the upper end of the front wheel fork (2) being fixedly connected to a longitudinally arranged front wheel spindle (21), the front wheel spindle (21) being connected to a front axle bracket (4) via bearings, characterized in that, The front axle bracket (4) includes a bracket base plate (42) with a main shaft mounting hole (41) and a pad plate (43) fixedly connected to the upper surface of the bracket base plate (42); the lower end of the front wheel main shaft (21) is fixedly connected to the front wheel fork (2) through a main shaft flange; the middle section of the front wheel main shaft (21) is fitted with a front wheel bushing (6) through a thrust radial bearing (5), and a bushing flange for connecting the bracket base plate (42) is provided on the outer wall of the front wheel bushing (6); the top end of the front wheel main shaft (21) is fixedly connected to a steering turntable (7), and a steering cylinder (8) is provided between the edge of the steering turntable (7) and the pad plate (43).

2. The steering mechanism of a three-wheeled tractor according to claim 1, characterized in that, The front wheel fork (2) includes a left fork plate (22) and a right fork plate (23) arranged parallel to each other, and a connecting plate (24) fixedly connected to the upper end of the left fork plate (22) and the right fork plate (23). A limiting hole (25) is provided in the middle of the connecting plate (24). The lower end of the front wheel spindle (21) has a limiting block (26) adapted to the limiting hole (25). The limiting block (26) is installed in the limiting hole (25).

3. The steering mechanism of a three-wheeled tractor according to claim 1 or 2, characterized in that, The steering wheel (7) has a spindle mounting hole (71) at its center, and cylinder connection holes (72) are symmetrically arranged on both sides of the spindle mounting hole (71). The top of the front wheel spindle (21) has a spindle connecting column (211), which is installed in the spindle mounting hole (71) of the steering wheel (7). The upper surface of the steering wheel (7) is fixedly connected to a cover plate (721) covering the spindle mounting hole (71). The center of the cover plate (721) is provided with a central bolt connected to the spindle connecting column (211), and the edge of the cover plate (721) is surrounded by multiple peripheral bolts connected to the steering wheel (7).

4. The steering mechanism of a three-wheeled tractor according to claim 1 or 2, characterized in that, The upper end of the front wheel bushing (6) is fixedly connected to a bearing upper end cover (61), and the lower end is fixedly connected to a bearing lower end cover (62). The bearing upper end cover (61) and the bearing lower end cover (62) are both ring structures that are fixedly connected to the end face of the front wheel bushing (6) by bolts. The inner ring surfaces of the bearing upper end cover (61) and the bearing lower end cover (62) are both clearance-fitted with the front wheel main shaft (21).

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