Double-wheel differential steering structure for unmanned sweeper
By employing a dual-wheel differential steering structure and mechanical centering design, the problems of large steering torque, severe tire wear, and high energy consumption in unmanned sweepers have been solved. This has resulted in higher centering accuracy and vehicle stability, reduced energy consumption and tire replacement frequency, and improved the operating efficiency and reliability of unmanned sweepers.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-08
- Publication Date
- 2026-03-13
AI Technical Summary
The steering structure of unmanned three-wheeled sweepers has problems such as large steering torque, severe tire wear, high energy consumption, large space occupation, low centering accuracy and complicated adjustment.
It adopts a dual-wheel differential steering structure, including EPS steering gear, right-angle planetary reducer, steering mounting base and locking nut, etc. Rolling friction steering is achieved through differential, and a mechanical centering structure is designed. High-precision planetary reducer and stable connection method are used to improve steering accuracy and stability.
It reduces energy consumption and tire wear, improves centering accuracy and vehicle driving stability, reduces the cost and space occupation of EPS steering gear, simplifies centering steps, and enhances the reliability and durability of steering system.
Smart Images
Figure CN223990059U_ABST
Abstract
Description
Technical Field
[0001] This utility model relates to the field of sweeper technology, and more specifically, to a dual-wheel differential steering structure for unmanned sweepers. Background Technology
[0002] In the sweeper industry, especially in the field of driverless three-wheeled sweepers, the performance of the steering structure plays a key role in the overall operation of the vehicle.
[0003] Currently, most driverless three-wheeled sweepers on the market use a single-wheel steering structure. This structure uses an EPS steering gear to drive the steering wheel through a sprocket and chain or gear reduction device. However, this structure has many drawbacks. The steering wheel experiences sliding friction with the ground, resulting in a large steering torque required, which can easily lead to accelerated tire wear and increased energy consumption. To meet the frequent turning requirements of driverless vehicles, either a high-power EPS steering gear or a larger sprocket and chain or gear reduction ratio must be used, but both of these methods occupy a large amount of space, increasing the difficulty of vehicle design and layout.
[0004] The steering wheel alignment relies entirely on EPS (Electric Power Steering) for alignment adjustment. However, the EPS controller itself has inherent errors, resulting in low alignment accuracy. Furthermore, the adjustment process is cumbersome and requires repeated operations. To achieve the required straight-line driving, the autonomous driving system has to frequently correct its course, causing the vehicle's trajectory to be S-shaped. This not only fails to meet the straight-line driving standard but also increases energy consumption and system load, reducing cleaning efficiency and overall vehicle performance. Utility Model Content
[0005] This specification provides a two-wheel differential steering structure for unmanned sweeping vehicles to overcome at least one technical problem existing in related technologies.
[0006] According to an embodiment of this specification, a dual-wheel differential steering structure for an unmanned sweeper is provided, comprising:
[0007] EPS steering gear, EPS steering gear mounting bracket, transition shaft, right-angle planetary reducer, steering mounting bracket, frame, steering fork, wheel axle, steering wheel, lock nut and adjusting bolt;
[0008] The EPS steering gear is mounted on the EPS steering gear mounting base. The output end of the EPS steering gear mounting base is connected to the input end of the right-angle planetary reducer via the transition shaft. The right-angle planetary reducer is mounted on the steering mounting base. The steering mounting base is assembled on the vehicle frame, and the mounting hole of the steering mounting base is an arc-shaped waist-shaped hole. One end of the steering fork is connected to the output end of the right-angle planetary reducer, and the other end of the steering fork is connected to the wheel axle. The steering wheel is mounted on the wheel axle. The locking nut is used to fix the wheel axle assembly, and the adjusting bolt is mounted on the steering mounting base.
[0009] In some alternative embodiments, the steering mount is connected to the vehicle frame by four mounting bolts, and the steering mount has two adjusting bolt holes through which the adjusting bolts pass so as to change the position of the steering mount relative to the vehicle frame by adjusting the adjusting bolts.
[0010] In some optional embodiments, the steering wheel adopts a two-wheel differential steering structure, which includes a differential and independent drive devices for the left and right steering wheels. The steering wheels achieve rolling friction steering through differential speed when steering.
[0011] In some alternative embodiments, the right-angle planetary reducer is a high-precision planetary reducer, in which multiple planetary gears move around the sun gear to achieve deceleration.
[0012] In some alternative embodiments, the locking nut is provided in two locations, one on each side of the axle.
[0013] In some alternative implementations, the EPS steering gear mounting bracket has a specific shape and size adapted to the EPS steering gear and is mounted on a designated location on the vehicle frame via bolt connection.
[0014] In some alternative embodiments, the steering fork is made of high-strength steel, one end of the steering fork is connected to the output end of the right-angle planetary reducer by a key, and the other end of the steering fork is connected to the wheel axle by a shaft hole fit.
[0015] In some alternative embodiments, the frame is provided with a positioning structure for mounting a steering mount, the positioning structure engaging with an arc-shaped oblong hole in the steering mount.
[0016] The beneficial effects of the embodiments in this specification are as follows:
[0017] 1. The technical solution of this application adopts a two-wheel differential steering structure, which changes the friction between the steering wheel and the ground from sliding friction to rolling friction. Compared with sliding friction, rolling friction significantly reduces the resistance experienced by the steering wheel when rotating. This means that under the same vehicle load, the steering wheel rotates more easily, and the required power of the EPS steering gear is also less, which not only reduces energy consumption but also lowers the cost and space occupation of the EPS steering gear. Since rolling friction causes less wear on the tires, tires of the same specifications will have a longer service life under the same conditions, reducing the frequency and cost of tire replacement.
[0018] 2. Traditional steering wheel alignment relies entirely on EPS (Electrical Power Steering) adjustment. The EPS controller itself has inherent errors, resulting in low alignment accuracy. Furthermore, the adjustment process is cumbersome and requires repeated operations. To meet straight-line driving standards, the autonomous driving system must frequently correct deviations, leading to an S-shaped vehicle trajectory. This application's technical solution designs a mechanical alignment structure. After vehicle assembly, the steering wheels are visually aligned using the EPS steering mechanism, followed by a straight-line driving test. If the vehicle veers, for example, to the left, simply loosen the mounting bolts and lock nuts of the steering mount, and adjust the bolts to slightly move the steering mount to the right; conversely, adjust it to the right. After adjustment, tighten the lock nuts and perform another straight-line driving test. If the straight-line requirement is still not met, further fine-tuning can be done. This mechanical alignment method eliminates the need for complex electronic control operations. The steering wheel alignment process is completed through simple mechanical component adjustments, avoiding the influence of EPS controller errors, significantly improving alignment accuracy, and simplifying the alignment process. This allows the vehicle to better meet straight-line driving standards and enhances driving stability.
[0019] 3. The technical solution of this application adopts a high-precision planetary reducer. During power transmission, the power output from the EPS steering gear is transmitted to the high-precision planetary reducer via the transition shaft, and then to the steering fork, thereby driving the wheel axle and steering wheel to rotate. The gears inside the high-precision planetary reducer have high machining precision and excellent assembly process. Compared with traditional reducers, it can transmit power to subsequent components more accurately during power transmission. This reduces energy loss and error accumulation during power transmission, making the rotation of the steering wheel more precise and the vehicle's steering action more stable and accurate. The use of a high-precision planetary reducer can improve the mechanical precision of the entire steering structure and enhance the reliability and durability of the unmanned sweeper's steering system. Attached Figure Description
[0020] To more clearly illustrate the technical solutions in the embodiments or related technologies of this specification, the drawings used in the description of the embodiments or related technologies will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0021] Figure 1 This is a schematic diagram of a two-wheel differential steering structure for an unmanned sweeper provided in an embodiment of this specification;
[0022] Figure 2 This is a structural diagram of the component of the adjusting bolt hole accessory in the dual-wheel differential steering structure for the unmanned sweeper provided in the embodiments of this specification.
[0023] Wherein, 1 represents EPS steering gear, 2 represents EPS steering gear mounting bracket, 3 represents transition shaft, 4 represents right-angle planetary reducer, 5 represents steering mounting bracket, 6 represents frame, 7 represents steering fork, 8 represents wheel axle, 9 represents steering wheel, 10 represents lock nut, 11 represents adjusting bolt, 12 represents adjusting bolt hole, 13 represents arc-shaped waist hole, and 14 represents center hole. Detailed Implementation
[0024] The present invention will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the present invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, the accompanying drawings show only the parts relevant to the present invention, not the entire structure.
[0025] In the description of this utility model, unless otherwise explicitly specified and limited, the terms "connected," "linked," and "fixed" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; 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; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this utility model based on the specific circumstances.
[0026] In this invention, unless otherwise explicitly specified and limited, "above" or "below" the second feature can include direct contact between the first and second features, or contact between the first and second features through another feature between them. Furthermore, "above," "over," and "on top" of the second feature includes the first feature directly above or diagonally above the second feature, or simply indicates that the first feature is at a higher horizontal level than the second feature. "Below," "below," and "under" the second feature includes the first feature directly below or diagonally below the second feature, or simply indicates that the first feature is at a lower horizontal level than the second feature.
[0027] In the description of this embodiment, the terms "upper," "lower," "right," etc., refer to the orientation or positional relationship shown in the accompanying drawings. They are used only for ease of description and simplification of operation, 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 utility model. In addition, the terms "first" and "second" are only used for distinction in description and have no special meaning.
[0028] This embodiment provides a dual-wheel differential steering structure for unmanned sweeping vehicles, such as... Figure 1As shown, the structure may include an EPS steering gear 1, an EPS steering gear mounting base 2, a transition shaft 3, a right-angle planetary reducer 4, a steering mounting base 5, a frame 6, a steering fork 7, a wheel axle 8, a steering wheel 9, a lock nut 10, and an adjusting bolt 11. The EPS steering gear 1 is mounted on the EPS steering gear mounting base 2. The output end of the EPS steering gear mounting base 2 is connected to the input end of the right-angle planetary reducer 4 via the transition shaft 3. The right-angle planetary reducer 4 is mounted on the steering mounting base 5. The steering mounting base 5 is mounted on the frame 6, and the mounting hole of the steering mounting base 5 is an arc-shaped oblong hole 13. One end of the steering fork 7 is connected to the output end of the right-angle planetary reducer 4, and the other end of the steering fork 7 is connected to the wheel axle 8. The steering wheel 9 is mounted on the wheel axle 8. The lock nut 10 is used to fix the wheel axle 8 component, and the adjusting bolt 11 is mounted on the steering mounting base 5.
[0029] The dual-wheel differential steering structure for unmanned sweeping vehicles provided in this application achieves vehicle steering and stable driving through the coordinated operation of multiple components. The power source for the entire system is the EPS steering gear 1, which is mounted on the EPS steering gear mounting base 2 to ensure stability during operation. After the EPS steering gear 1 starts, it outputs power, which is transmitted to the input end of the right-angle planetary reducer 4 via the transition shaft 3. The right-angle planetary reducer 4 has multiple planetary gears orbiting the sun gear. This structure achieves speed reduction, outputting torque more suited to steering requirements, and transmitting it to the steering fork 7. One end of the steering fork 7 is connected to the output end of the right-angle planetary reducer 4 via a key. This connection ensures effective torque transmission and guarantees that the steering fork 7 rotates synchronously with the right-angle planetary reducer 4. The other end of the steering fork 7 is connected to the wheel axle 8. When the steering fork 7 rotates, it drives the wheel axle 8 and the steering wheels 9 mounted on the wheel axle 8 to rotate, thereby achieving vehicle steering. The steering wheels 9 employ a dual-wheel differential steering structure, where the two steering wheels 9 rotate at different speeds during vehicle steering. Taking a right turn as an example, the differential mechanism automatically adjusts to reduce the speed of the left wheel and increase the speed of the right wheel, causing the steering wheel to contact the ground through rolling friction. Compared with traditional sliding friction steering, this greatly reduces the steering wheel resistance torque, making the vehicle steering more flexible and efficient. The steering mount 5 is mounted on the frame 6, and its mounting hole is an arc-shaped waist-shaped hole 13, allowing the steering mount 5 to rotate ±5° relative to the frame 6 around the center hole 14. After the vehicle is assembled, the steering wheel 9 is first visually aligned by the controller of the EPS steering gear 1. Then, a straight-line driving test is conducted. If the vehicle veers to the left, the four mounting bolts and two locking nuts 10 of the steering mount 5 are loosened, and the steering mount 5 is slightly adjusted to the right by rotating the two adjusting bolts 11; conversely, if the vehicle veers to the right, the steering mount 5 is slightly adjusted to the left. After adjustment, tighten nut 10 and retest the vehicle's straight-line driving. If it still does not meet the straight-line driving standard requirements, continue to fine-tune according to the above method until the standard is met, and complete the steering wheel alignment process to ensure the straight-line stability of the vehicle.
[0030] Based on the technical solutions described above, some more specific technical solutions are provided below, which will be elaborated on separately.
[0031] In the optional embodiment technical solutions, such as Figure 2 As shown, the steering mount 5 can be connected to the frame 6 by four mounting bolts. The steering mount 5 is provided with two adjusting bolt holes, through which the adjusting bolt 11 passes, so as to change the position of the steering mount 5 relative to the frame 6 by adjusting the adjusting bolt 11.
[0032] In this embodiment, the steering mount 5 is connected to the frame 6 via four mounting bolts. This multi-bolt connection provides stable and balanced support for the steering mount 5, ensuring a tight fit between the steering mount 5 and the frame 6 during vehicle operation, preventing displacement or loosening due to vibration, bumps, or forces generated during steering. The four mounting bolts are evenly distributed at the connection point between the steering mount 5 and the frame 6, resulting in uniform connection strength and effectively resisting forces from different directions, thus ensuring the overall stability of the steering structure. The steering mount 5 has two adjusting bolt holes, the positions of which match the arc-shaped mounting holes of the steering mount 5 and the vehicle's steering alignment requirements. The diameter of the adjusting bolt holes must precisely match the size of the adjusting bolts 11 to ensure that the adjusting bolts 11 can pass smoothly and rotate flexibly within the holes, while also possessing a certain degree of tightness to ensure that the adjusting bolts 11 do not wobble during adjustment, thereby guaranteeing adjustment accuracy.
[0033] In this embodiment, the adjusting bolt 11 passes through the adjusting bolt hole, and its main function is to change the position of the steering mount 5 relative to the frame 6. After the unmanned sweeper undergoes a straight-line driving test, if the vehicle veers off course, the steering wheels need to be fine-tuned. At this time, the four mounting bolts are loosened first, allowing the steering mount 5 to rotate around the center hole 14 within the allowable range of the arc-shaped hole 13. If the vehicle veers to the left, the adjusting bolt 11 is rotated to push or pull the steering mount 5 to the right; conversely, if the vehicle veers to the right, the steering mount 5 is fine-tuned to the left. After adjustment, the four mounting bolts are tightened to ensure the new position of the steering mount 5 is fixed. In this way, precise adjustment of the steering wheel angle can be achieved, thereby meeting the standard requirements for vehicle straightness and improving the stability and maneuverability of the unmanned sweeper.
[0034] In an optional embodiment, the steering wheel 9 can adopt a dual-wheel differential steering structure, which includes a differential and independent drive devices for the left and right steering wheels. The two steering wheels 9 achieve rolling friction steering through differential speed when steering.
[0035] In this embodiment, the dual-wheel differential steering structure improves the vehicle's steering performance and operating efficiency. Its specific working principle is as follows: From the perspective of the structure and principle of the dual-wheel differential steering structure, the steering wheels 9 of the unmanned sweeper adopt a dual-wheel differential steering structure. This structure consists of two steering wheels working together and equipped with a differential device. The differential device can automatically and precisely adjust the speed of the left and right steering wheels according to the vehicle's steering requirements. When the vehicle performs a steering action, the speeds of the two steering wheels 9 are not the same. Taking a right turn as an example, the left wheel is the inner steering wheel, and the right wheel is the outer steering wheel. The differential device will reduce the speed of the left wheel while increasing the speed of the right wheel. This speed difference allows the vehicle to complete the steering operation in a more reasonable and smooth manner. From the perspective of the transformation from sliding friction to rolling friction, in the traditional single-wheel steering structure, the contact between the steering wheel and the ground is sliding friction, and the steering wheel slides relative to the ground during steering. The dual-wheel differential steering structure changes this situation. By adjusting the speed of the two wheels through the differential device, the steering wheels can contact the ground in a near-pure rolling state during steering, thus converting sliding friction into rolling friction. Compared to sliding friction, rolling friction has a lower coefficient of friction, which significantly reduces the resistance experienced by the steering wheels during rotation.
[0036] Meanwhile, the rolling friction steering method employed in this application significantly reduces the steering wheel resistance torque. According to the formula for calculating friction torque, under the same normal force and steering wheel radius, the rolling friction resistance torque is much smaller than the sliding friction resistance torque. This means that the resistance the vehicle needs to overcome during steering is reduced, thereby lowering energy consumption and lessening the burden on the steering mechanism. Rolling friction also causes less tire wear; tires of the same specifications have a longer service life when using rolling friction steering, reducing the frequency and cost of tire replacement and improving the economy and reliability of the unmanned sweeper operation.
[0037] In an optional embodiment, the right-angle planetary reducer 4 can be a high-precision planetary reducer, wherein the internal structure of the high-precision planetary reducer consists of multiple planetary gears moving around the sun gear to achieve deceleration.
[0038] In this embodiment, the high-precision planetary reducer mainly consists of a sun gear, multiple planet gears, and an internal gear ring. The sun gear is located at the center of the entire structure, and multiple planet gears are evenly distributed around the sun gear, meshing with both the sun gear and the internal gear ring. This arrangement allows the planet gears to rotate on their own axes while revolving around the sun gear, achieving power transmission and speed reduction through gear combinations.
[0039] In an optional embodiment, the locking nut 10 is provided in two places, located on both sides of the axle 8.
[0040] In this embodiment, the locking nuts 10 are located on both sides to ensure the steering wheel 9 and related components are securely mounted on the axle 8, improving the overall stability of the steering structure. A stable steering structure ensures the steering wheel 9 rotates along the expected trajectory, making the vehicle drive more smoothly. If components become loose, the installation position of the steering wheel 9 changes, affecting the vehicle's steering performance and straight-line accuracy. The locking nuts 10 on both sides reduce wear caused by component loosening, extending the service life of each component in the steering structure, reducing maintenance costs and frequency, and thus improving the operational reliability of the unmanned sweeper.
[0041] In an optional embodiment, the EPS steering gear mounting base 2 has a specific shape and size adapted to the EPS steering gear 1, and is installed at a designated position on the vehicle frame 6 by means of bolt connection.
[0042] In this embodiment, the specific shape and size of the EPS steering gear mounting base 2 are adapted to the EPS steering gear 1. Its shape must precisely match the outer contour of the EPS steering gear 1 to ensure a tight fit during installation. In terms of dimensions, the mounting holes on the mounting base perfectly match the corresponding holes on the EPS steering gear 1, ensuring that the EPS steering gear 1 can be accurately installed on the mounting base. This adaptation design ensures a stable installation of the EPS steering gear 1, avoiding problems such as insecure installation and shaking caused by shape or size mismatch.
[0043] Meanwhile, the EPS steering gear mounting bracket 2 is installed at a designated position on the frame 6 via bolt connection. During installation, multiple bolts are used to firmly secure the mounting bracket to the frame. The bolt connection offers high tightness and reliability; the even distribution of multiple bolts at the connection point ensures a more stable connection between the mounting bracket and the frame. During vehicle operation, the EPS steering gear 1 is subjected to various external forces, such as the torque generated during steering and the impact force from vehicle vibration. The tightness provided by the bolt connection effectively resists these external forces, ensuring that the EPS steering gear mounting bracket 2 and the EPS steering gear 1 mounted on it remain fixed to the frame 6 without displacement or loosening. The bolt connection also facilitates installation and disassembly; during equipment maintenance or component replacement, the EPS steering gear mounting bracket 2 can be easily removed from the frame 6, improving maintenance convenience.
[0044] In an optional embodiment, the steering fork 7 can be made of high-strength steel. One end of the steering fork 7 is connected to the output end of the right-angle planetary reducer 4 via a key, and the other end of the steering fork 7 is connected to the wheel axle 8 via a shaft hole fit.
[0045] In this embodiment, considering the complex loads such as the torque transmitted from the right-angle planetary reducer 4 and the ground reaction force on the steering wheel 9 during the operation of the unmanned sweeper, the steering fork 7 can be made of high-strength steel. High-strength steel possesses high yield strength and tensile strength, effectively resisting these external forces and preventing deformation or damage during long-term use. For example, when the vehicle turns, the steering fork 7 is subjected to significant bending and shear forces. Ordinary steel may not be able to withstand these forces, leading to fatigue cracks or even breakage. High-strength steel, with its superior properties, ensures the durability and reliability of the steering fork 7, guaranteeing the stable operation of the unmanned sweeper's steering system.
[0046] Meanwhile, one end of the steering fork 7 is connected to the output end of the right-angle planetary reducer 4 via a key. Key connection is a common mechanical transmission connection method. Its principle is that the side of the key tightly engages with the keyway on the output shaft of both the steering fork 7 and the right-angle planetary reducer 4, achieving circumferential fixation and torque transmission. When the unmanned sweeper turns, the right-angle planetary reducer 4 outputs torque, and the key reliably transmits this torque to the steering fork 7, ensuring synchronous rotation. The key connection structure is simple, has high centering accuracy, and is easy to install and disassemble. It reduces relative sliding and wear, improves the efficiency and accuracy of power transmission, and allows the steering wheel 9 to rotate at the expected speed and direction, enhancing the stability and maneuverability of the unmanned sweeper's steering.
[0047] The other end of the steering fork 7 is connected to the wheel axle 8 via a shaft hole fit. The shaft hole fit is achieved through careful design of the dimensions, tolerances, and surface roughness of the steering fork 7's shaft hole, ensuring a tight fit with the wheel axle 8. Generally, a transition fit or interference fit is used to guarantee connection strength and stability. During vehicle steering, the steering fork 7 transmits the power from the right-angle planetary reducer 4 to the wheel axle 8, driving the steering wheel 9 mounted on the wheel axle 8 to rotate. The stability of this connection method is crucial to the motion accuracy of the steering wheel 9 and the reliability of the steering system, effectively preventing steering abnormalities caused by loose connections and ensuring the safe operation of the unmanned sweeper.
[0048] In the optional embodiment technical solutions, such as Figure 2 As shown, the frame 6 is provided with a positioning structure for mounting the steering mount 5, which mates with the arc-shaped waist-shaped hole 13 of the steering mount 5.
[0049] In this embodiment, the shape, size, and position of the positioning structure on the frame 6 must precisely match the arc-shaped waist-shaped hole of the steering mount 5. When installing the steering mount 5, the positioning structure guides it to be accurately installed in the designated position on the frame 6, ensuring the accuracy of the initial installation position of the steering mount 5 and avoiding installation deviations. This not only improves assembly efficiency but also ensures the relative positional accuracy of each component of the steering system, enabling the entire steering structure to work collaboratively as designed.
[0050] Meanwhile, the arc-shaped oblong hole of the steering mount 5 allows it to rotate within a range of ±5° relative to the frame 6 around the central hole 14. During the mating process, the positioning structure both constrains the rotation of the steering mount 5, ensuring it moves within a specified angle, and guarantees its flexible rotation. When centering the steering wheels is required, the steering mount 5 can rotate within the arc-shaped oblong hole range, guided by the positioning structure. The position can be finely adjusted by adjusting the bolt 11, thereby changing the steering wheel angle and achieving precise adjustment of the steering wheels to meet the vehicle's straightness requirements.
[0051] During the operation of the unmanned sweeper, the positioning structure and the arc-shaped waist-shaped hole ensure the positional stability of the steering mount 5 relative to the frame 6. Even if the vehicle is subjected to external forces such as vibration, bumps, or steering forces during operation, the positioning structure can prevent the steering mount 5 from losing control of its displacement, ensuring that the steering wheels move along the preset trajectory. This helps to improve the accuracy and stability of vehicle steering, reduce problems such as deviation and vibration during vehicle operation, and improve the safety and reliability of the unmanned sweeper.
[0052] In traditional single-wheel steering structures, the steering wheel experiences sliding friction with the ground. When the vehicle turns, the steering wheel must overcome significant friction, requiring a large steering torque. This necessitates the use of a high-power EPS steering gear or a larger sprocket, chain, and gear reduction ratio, which occupies considerable space. The technical solution presented in this application employs a dual-wheel differential steering structure, transforming the sliding friction between the steering wheel and the ground into rolling friction. Compared to sliding friction, rolling friction significantly reduces the resistance experienced by the steering wheel during rotation. This means that under the same vehicle load, the steering wheel rotates more easily, requiring less power from the EPS steering gear, thus reducing energy consumption and lowering the cost and space occupied by the EPS steering gear. Furthermore, rolling friction causes less tire wear, allowing tires of the same specifications to have a longer service life under the same conditions, reducing tire replacement frequency and cost. Traditional steering wheel alignment relies entirely on EPS alignment adjustment, but the EPS controller itself has inherent errors, resulting in low alignment accuracy. Moreover, the adjustment process is cumbersome and requires repeated operations. To meet straight-line driving standards, the autonomous driving system must frequently correct course, resulting in an S-shaped vehicle trajectory. This application's technical solution incorporates a mechanical alignment structure. After vehicle assembly, the steering wheels are visually aligned using the EPS steering system, followed by a straight-line driving test. If the vehicle veers, for example, to the left, simply loosen the mounting bolts and lock nuts of the steering mount, and adjust the bolts to slightly move the steering mount to the right; conversely, adjust it to the right. After adjustment, tighten the lock nuts and perform another straight-line driving test. If the straightness requirement is still not met, further fine-tuning can be done. This mechanical alignment method eliminates the need for complex electronic control operations; the steering wheel alignment process is completed solely through simple mechanical component adjustments. This avoids the influence of EPS controller errors, significantly improving alignment accuracy and simplifying the alignment process, enabling the vehicle to better meet straight-line driving standards and enhancing driving stability.
[0053] Meanwhile, the technical solution of this application employs a high-precision planetary reducer. During power transmission, the power output from the EPS steering gear is transmitted via a transition shaft to the high-precision planetary reducer, then to the steering fork, thereby driving the wheel axle and steering wheels to rotate. The high-precision planetary reducer features gears with high machining precision and excellent assembly processes, enabling more accurate power transmission to subsequent components compared to traditional reducers. This reduces energy loss and error accumulation during power transmission, resulting in more precise steering wheel rotation and more stable and accurate vehicle steering. The use of a high-precision planetary reducer improves the mechanical precision of the entire steering structure and enhances the reliability and durability of the unmanned sweeper's steering system.
[0054] Obviously, the above embodiments of this utility model are merely examples for clearly illustrating the present utility model, and are not intended to limit the implementation of the present utility model. Those skilled in the art can make various obvious changes, readjustments, and substitutions without departing from the protection scope of this utility model. It is neither necessary nor possible to exhaustively describe all embodiments here. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of this utility model should be included within the protection scope of the claims of this utility model.
Claims
1. A dual-wheel differential steering structure for an unmanned sweeper vehicle, characterized in that, The application relates to an EPS steering machine (1), an EPS steering machine mounting seat (2), a transition shaft (3), a right-angle planetary reducer (4), a steering mounting seat (5), a frame (6), a steering fork (7), an axle (8), a steering wheel (9), a locking nut (10) and an adjusting bolt (11). The EPS steering machine (1) is mounted on the EPS steering machine mounting seat (2), the output end of the EPS steering machine mounting seat (2) is connected with the input end of the right-angle planetary reducer (4) through the transition shaft (3), and the right-angle planetary reducer (4) is mounted on the steering mounting seat (5); the steering mounting seat (5) is assembled on the frame (6), the mounting hole of the steering mounting seat (5) is an arc waist-shaped hole (13); one end of the steering fork (7) is connected with the output end of the right-angle planetary reducer (4), the other end of the steering fork (7) is connected with the axle (8), the steering wheel (9) is mounted on the axle (8), the locking nut (10) is used for fixing the axle (8) component, and the adjusting bolt (11) is mounted on the steering mounting seat (5). The steering mounting seat (5) is connected with the frame (6) through four mounting bolts, the steering mounting seat (5) is provided with two adjusting bolt holes, the adjusting bolt (11) passes through the adjusting bolt holes, so that the position of the steering mounting seat (5) relative to the frame (6) is changed by adjusting the adjusting bolt (11).
2. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, characterized by The steering wheel (9) adopts a double-wheel differential steering structure, the double-wheel differential steering structure comprises a differential and left and right steering wheel independent driving devices, and the steering wheel (9) realizes rolling friction steering through differential when steering.
3. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, wherein The right-angle planetary reducer (4) adopts a high-precision planetary reducer, the inside of the high-precision planetary reducer is surrounded by a plurality of planetary gears to move around a sun gear to realize speed reduction.
4. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, characterized in that The locking nut (10) is arranged at two positions respectively located on the two sides of the axle (8).
5. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, wherein The specific shape and size of the EPS steering machine mounting seat (2) are matched with the EPS steering machine (1), and the EPS steering machine mounting seat (2) is mounted on the specified position of the frame (6) through a bolt connection mode.
6. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, wherein The steering fork (7) is made of high-strength steel, one end of the steering fork (7) is connected with the output end of the right-angle planetary reducer (4) through a key, and the other end of the steering fork (7) is connected with the axle (8) through a shaft hole matching mode.
7. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, wherein The frame (6) is provided with a positioning structure for mounting the steering mounting seat (5), and the positioning structure is matched with the arc waist-shaped hole (13) of the steering mounting seat (5).
8. The twin-wheel differential steering structure for an unmanned sweeper according to claim 1, wherein