A reverse drive preventing device for a vehicle and a control system thereof

Abstract

The present application relates to the field of carrier steering control, in particular to a carrier reverse drive device and a control system thereof. The reverse drive device comprises large umbrella gear, small umbrella gear, large straight gear, small straight gear, worm and turbine which are engaged in sequence. The large umbrella gear is fixed with an input shaft, the small straight gear is coaxial with the worm, and the turbine is fixed with an output shaft. When the worm is driven and the turbine is driven, clockwise and counterclockwise rotation of the input shaft is transmitted to the output shaft. When external force acts on the turbine through the output shaft to try to drive the worm in reverse, the self-locking effect of the worm and the turbine is used to cut off the force flow, realize the reverse of the output shaft relative to the input shaft, and weaken the beating hand and high-speed swing. The input shaft and the output shaft are coaxially arranged through a coaxial device, and each gear and the worm and the worm wheel are installed in a shaft box. The control system is provided with sensors for angular velocity, temperature, vibration and working cycle number, and signals are input into an electronic control unit to implement state monitoring and fault early warning.

Description

Technical Field

[0001] This invention relates to the field of vehicle steering control, specifically to a vehicle reverse transmission device and its control system. Background Technology

[0002] In existing vehicle steering systems, mechanical steering structures still dominate. Typical designs involve the steering wheel forming a rigid or near-rigid connection with the front wheel steering structure via a steering shaft, universal joint, rack and pinion, or rocker arm mechanism. While this type of structure offers a simple transmission link and low manufacturing cost, it also exhibits a significant bidirectional force transmission characteristic. Driver's steering force can be smoothly transmitted to the wheel side, while external forces such as road impacts, sudden changes in adhesion conditions, or wheel oscillations can also be transmitted back along the same path to the steering wheel or handlebars. Under complex road conditions, high speeds, or sudden load changes, especially in relatively lightweight vehicles such as two-wheeled and three-wheeled vehicles, a sudden steering wheel backlash ("kickback") and progressively amplified shimmy in the front wheels and the entire vehicle ("high-speed shimmy") can easily occur, potentially leading to loss of driver control in severe cases. To combat the aforementioned adverse working conditions, existing technologies have attempted to suppress them by adding passive dampers, increasing steering system friction, or using structural reinforcements. However, these methods mostly involve simply increasing damping or stiffness, making it difficult to effectively isolate external forces on the wheel side from the perspective of force flow direction control. Furthermore, they may introduce new problems such as heavy steering and poor handling feel at low speeds and when parking.

[0003] To improve steering comfort and safety, some technologies have proposed adding hydraulic or electric power steering to mechanical steering, or even introducing electronic stability control systems, to suppress vehicle instability by controlling front wheel angle, braking force, or driving force. However, these solutions typically control the overall vehicle dynamics, and the steering transmission chain itself remains primarily bidirectional, failing to achieve unidirectional force flow management at the structural level—allowing for forward transmission but restricting reverse flow. For lightweight vehicles with limited space and cost sensitivity, introducing complex hydraulic or electronic control systems not only increases structural complexity, manufacturing and maintenance costs, but also introduces dependence on the reliability of power supplies, controllers, and sensors, making it difficult to promote in a wide range of applications. Furthermore, while there are solutions applying worm gears and self-locking mechanisms to other transmission applications, these are mostly used for lifting, braking, or general transmission self-locking. However, they lack specific structural designs for achieving coaxial arrangement of the input and output shafts within limited axial space while considering the steering system's feel, road feel, and reliability requirements, and have not yet effectively solved the aforementioned steering safety hazards such as hitch and high-speed shimmy.

[0004] On the other hand, existing methods for monitoring the condition of steering systems or transmission assemblies are still relatively rudimentary, relying heavily on periodic manual inspections, routine maintenance, or vehicle-level diagnostics to identify problems. For backstop transmissions, which include multi-stage transmission mechanisms such as gear pairs and worm gear pairs, problems such as tooth surface wear, increased meshing clearance, deterioration of lubrication, and bearing damage gradually accumulate over time, eventually leading to decreased self-locking performance, abnormal meshing, or localized overheating. However, traditional solutions often lack dedicated online monitoring mechanisms for such devices, making it impossible to identify and warn of the degradation trend of the backstop function through comprehensive analysis of multiple parameters such as angular velocity, temperature, vibration, and number of working cycles. Existing simplified monitoring methods that rely on a single temperature or vibration threshold are insufficient to accurately reflect the overall health status of the worm gear and the entire transmission chain, and are prone to problems such as delayed fault detection, insensitive warnings, or high false alarm rates, which to some extent restricts the reliable application of backstop transmissions in critical steering applications. Summary of the Invention

[0005] The purpose of this invention is to provide a reverse transmission device for a vehicle and its control system to solve the technical problems mentioned in the background art.

[0006] Based on the above ideas, the present invention provides the following technical solution:

[0007] A reverse transmission device for a vehicle, comprising:

[0008] Input shaft, output shaft, large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel;

[0009] The large bevel gear is fixedly connected to the input shaft and meshes with the small bevel gear. The small bevel gear is coaxially fixed with the large straight gear. The large straight gear meshes with the small straight gear. The small straight gear is coaxially fixed with the worm. The worm meshes with the worm wheel. The worm wheel is fixedly connected to the output shaft.

[0010] In the forward transmission state where the worm drives the worm wheel, the clockwise or counterclockwise rotation of the input shaft is transmitted to the output shaft via the large bevel gear, small bevel gear, large straight gear, small straight gear, worm, and worm wheel, causing the output shaft to rotate synchronously clockwise or counterclockwise. When an external force generated by the vehicle's driving condition acts on the worm wheel through the output shaft in an attempt to reverse the worm, the self-locking effect between the worm and the worm wheel prevents the worm, the large straight gear, small straight gear, small bevel gear, large bevel gear, and the input shaft from being reverse-driven, thereby achieving reverse transmission for the output shaft.

[0011] The transmission chain arrangement, consisting of an input shaft, large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel meshing sequentially and ultimately driving the output shaft, ensures that clockwise or counterclockwise torque applied by the operator to the input shaft is reliably amplified and transmitted to the output shaft in a forward transmission state where the worm gear is the active component and the worm wheel is the driven component. This achieves stable and linear steering of the front wheels. Simultaneously, when external forces generated by the vehicle's driving conditions act in the opposite direction to the worm wheel via the output shaft, the self-locking characteristic between the worm gear and the worm wheel cuts off the reverse transmission path from the output shaft to the input shaft. This prevents disturbances such as road impacts and sudden changes in adhesion from being directly transmitted back to the handlebars, thereby significantly reducing steering kickback and the risk of high-speed swaying, and improving the handling stability and driving safety of the steering system.

[0012] Preferably, it further includes a coaxial connector, through which the input shaft and the output shaft are arranged coaxially in the axial direction, the coaxial connector being used to maintain the coaxiality of the input shaft and the output shaft and to disengage the rigid connection between the input shaft and the output shaft.

[0013] By installing a coaxial connector between the input and output shafts and arranging them coaxially in the axial direction via the connector, a high degree of coaxiality between the input and output shafts can be maintained structurally. This facilitates the integration of the reverse-stop transmission device into the existing steering column structure or its placement within a limited axial space, reducing assembly difficulty. Furthermore, the coaxial connector breaks the rigid connection between the input and output shafts, allowing them to absorb a certain amount of relative displacement and torsional micro-displacement when subjected to impact loads, installation errors, or thermal deformation. This reduces local stress concentration, extends the service life of the shaft system and gear pairs, and further weakens the transmission of high-frequency vibrations from the wheel side to the handlebar side.

[0014] Preferably, the large bevel gear and the small bevel gear form a bevel gear pair that changes the transmission direction, used to convert the rotational torque transmitted along the input shaft axial direction into the transmission torque in the plane where the large spur gear and the small spur gear are located, so that the large bevel gear, the small bevel gear, the large spur gear, the small spur gear, the worm gear and the worm wheel form a three-dimensional spatial transmission structure.

[0015] By constructing a bevel gear pair with large and small bevel teeth to change the transmission direction, the rotational torque transmitted along the input shaft axis is converted into a transmission torque located in the plane containing the axial directions of the large and small spur teeth. This allows the bevel gear pair, together with the subsequent spur gear set, worm gear, and worm wheel, to form a three-dimensional spatial transmission structure. This achieves a reasonable reconstruction of the transmission direction and force flow path without increasing the axial dimension, facilitating the arrangement of multi-stage speed change and backstop units within a compact axle box. This structural layout helps reduce the overall size and weight of the device, improves adaptability to different frame layout spaces and installation postures, and balances good stress state and transmission efficiency.

[0016] Preferably, it also includes a shaft box, in which the large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel are all installed, and the input shaft and the output shaft pass through the shaft box.

[0017] By setting up an axle box and installing the large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel as a whole inside the axle box, the gear pairs and worm gear pairs at each stage work in a relatively closed cavity. This facilitates the formation of a centralized lubrication and sealing protection structure, which not only reduces the intrusion of external dust, moisture, and other impurities into the meshing pairs, reducing wear and the probability of failure, but also enables modular assembly through the design of the axle box shape and mounting holes. This allows the input and output shafts to directly connect with the vehicle structure by passing through the axle box, improving the overall rigidity and assembly accuracy of the device, and facilitating mass production and maintenance replacement.

[0018] Preferably, a first three-star platform is installed at one end of the input shaft, and a second three-star platform is installed at one end of the output shaft. The first three-star platform is used to connect with a steering wheel for steering, and the second three-star platform is used to connect with a steering structure for the wheels for steering. The axle box is mounted on the vehicle via a frame.

[0019] By installing a first three-star platform at one end of the input shaft and a second three-star platform at one end of the output shaft, with the first three-star platform connected to the steering wheel for steering and the second three-star platform connected to the wheel steering structure for steering, and the axle box mounted on the vehicle via the frame, the reverse drive device can be naturally embedded into the force chain of the traditional steering wheel, steering column, and front wheel steering structure, achieving standardization and universality of the handlebar-side and wheel-side interface. This arrangement is beneficial for preserving the original steering linkage or front fork structure of the vehicle, and facilitates modification and upgrades without significant changes to the overall vehicle layout, thereby reducing engineering development costs and modification barriers, and making the reverse drive function easier to promote and apply on different types of vehicles.

[0020] Preferably, the input shaft can rotate clockwise or counterclockwise around its axis under the action of external operating force and drive the output shaft to rotate synchronously clockwise or counterclockwise via the large bevel gear, small bevel gear, large straight gear, small straight gear, worm gear and worm wheel. However, when external force is applied to the output shaft through the wheel and the second triangular platform, the output shaft cannot drive the input shaft in the opposite direction via the worm wheel, worm gear, small straight gear, large straight gear, small bevel gear and large bevel gear.

[0021] Even if the input shaft can rotate clockwise or counterclockwise around its axis under external operating force and drive the output shaft to rotate synchronously through the gear chain, worm, and worm wheel, when external force acts on the output shaft through the wheel and the second three-star platform, the output shaft cannot form a reverse drive through the worm wheel, worm, gears of each stage, and input shaft. This clearly distinguishes the working mechanism of forward transmission and reverse self-locking. This limitation helps to ensure that in actual use, regardless of whether the vehicle is in low-speed steering, high-speed straight driving, or encountering sudden impact, the mechanical isolation between the wheel side and the handle side can be stably achieved, improving the consistency and predictability of steering operation and reducing driver fatigue.

[0022] Preferably, the module, number of teeth, and number of starts of the large bevel gear, small bevel gear, large straight gear, small straight gear, worm gear, and worm wheel are selected and replaced as needed to adjust the transmission speed ratio and transmission direction between the input shaft and the output shaft.

[0023] By setting the module, number of teeth, and number of starts of the large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel to be selectable and replaceable as needed, the transmission ratio and transmission direction between the input and output shafts become adjustable. This facilitates parametric design and serial configuration for vehicles with different masses, wheelbases, front wheel loads, and desired steering feel. This feature allows for the matching and optimization of steering sensitivity, power assist, and return-to-center characteristics while maintaining the backstop function, providing greater calibration and selection space for vehicle development and enhancing the versatility and engineering application value of this device.

[0024] Preferably, the vehicle has a steering mechanism that enables steering through wheels, the input shaft is connected to a steering wheel and / or handle for operating steering via a first three-star platform, and the output shaft is connected to a wheel steering structure in the steering mechanism via a second three-star platform, thereby constituting the steering device of the vehicle.

[0025] By defining the vehicle as having a steering mechanism that achieves steering through wheels, and specifying that the input shaft is connected to the steering wheel for steering via a first three-star platform and the output shaft is connected to the wheel steering structure in the steering mechanism via a second three-star platform, this reverse transmission device constitutes part of a complete steering device at the system level. It can directly replace or insert into the original steering column position without changing the basic steering architecture of the vehicle, forming a unified force flow channel. This connection method makes the device suitable for both synchronous design of new models and aftermarket modification of existing models, thereby expanding the scope of application and market prospects of the invention.

[0026] A control system for a vehicle-mounted backstop transmission device, using the aforementioned backstop transmission device, further includes: an input shaft angular velocity sensor mounted on the input shaft for detecting the angular velocity of the input shaft; an output shaft angular velocity sensor mounted on the output shaft for detecting the angular velocity of the output shaft; an axle box temperature sensor mounted on the axle box wall or near the bearing seat for detecting the internal temperature of the axle box; a vibration sensor mounted on the outer surface of the axle box for detecting vibration acceleration at the axle box and calculating vibration characteristic quantities; an encoder is set on the input shaft or output shaft to count the cumulative working cycles of the backstop transmission device; the output signal is connected to an electronic control unit, a built-in memory and a processor, for executing the status monitoring and fault warning algorithm of this embodiment; the output terminals of the electronic control unit, the built-in memory and the processor are connected to an audible and visual alarm unit for issuing warning information to the driver or maintenance personnel.

[0027] The working principle is as follows:

[0028] In use, the operator rotates the handle of the first three-star platform connected to the input shaft, causing the input shaft to rotate clockwise or counterclockwise around its axis. The input shaft drives the large bevel gear, which is fixedly connected to it, to rotate. The large bevel gear meshes with the small bevel gear, and the small bevel gear is coaxially fixed with the large straight gear and drives the large straight gear to rotate. The large straight gear meshes with the small straight gear, and the small straight gear is coaxially fixed with the worm and drives the worm to rotate. The worm meshes with the worm wheel, and the worm wheel is fixedly connected to the output shaft. In the forward transmission state where the worm is active and the worm wheel is driven, the output shaft rotates synchronously clockwise or counterclockwise with the input shaft. The rotational torque is transmitted to the wheel steering structure through the second three-star platform set at one end of the output shaft, realizing the normal steering of the front wheels of the vehicle.

[0029] During vehicle operation, when external forces such as uneven road surface, crosswinds, or changes in adhesion conditions act on the second three-star platform through the wheels and its steering structure, and the second three-star platform drives the output shaft and worm gear to generate a passive rotation tendency, the worm gear attempts to drive the small spur gear, large spur gear, small bevel gear, large bevel gear, and input shaft in the opposite direction through the worm gear meshing with it. However, in the reverse transmission state where the worm gear is active and the worm gear is driven, the worm gear and worm wheel meet the self-locking condition, and the worm gear is difficult to effectively drive the worm gear to rotate, thereby preventing the above gear transmission chain and input shaft from being driven in the opposite direction, realizing the reverse transmission of the output shaft relative to the input shaft, and reducing the back transmission of external forces from the wheel side to the handle side.

[0030] The technical solution of the present invention may include the following beneficial effects:

[0031] This invention, by sequentially arranging a bevel gear pair, a spur gear pair, and a worm-worm wheel pair between the input and output shafts, ensures smooth transmission of the operator's forward steering force to the wheel steering mechanism. Simultaneously, it utilizes the self-locking meshing relationship between the worm and worm wheel to construct a reverse-locking transmission chain that allows forward transmission but cuts off in the reverse direction. When the driver actively steers, the input shaft sequentially drives the worm wheel and output shaft via the large bevel gear, small bevel gear, large spur gear, small spur gear, and worm, achieving synchronous wheel steering. However, when external forces such as road impacts, sudden changes in adhesion conditions, or vibrations act in the opposite direction on the output shaft from one side of the wheel, the force flow attempting to reverse the worm's drive is self-locked at the worm wheel-worm gear meshing point, making it difficult to further transmit to the spur gear set and bevel gear set. The input shaft and the connected steering wheel / handle remain essentially stable. This significantly reduces adverse operating conditions such as kickback and high-speed sway, improving the steering system's handling stability and overall vehicle driving safety.

[0032] This invention changes the transmission direction by using large and small bevel gears, redirecting the rotational torque transmitted axially along the input shaft to the plane of the spur gear set. The spur gear set then drives the worm and worm wheel, thus forming a compact three-dimensional spatial transmission structure within the axle box. The input and output shafts are coaxially arranged via a coaxial connector. The entire axle box is mounted on the vehicle frame. The input shaft end has a first three-star platform for connection to the steering wheel, and the output shaft end has a second three-star platform for connection to the wheel steering components. This structural design allows the backstop transmission device to be directly replaced or embedded in the existing steering column as an integrated module, simultaneously achieving multi-stage speed change and backstop functions within a limited installation space. It facilitates assembly, positioning, and sealing lubrication, improving the overall rigidity, meshing accuracy, and long-term reliability of the transmission system while reducing maintenance costs.

[0033] This invention designs the modules, number of teeth, and number of starts of the large bevel gear, small bevel gear, large spur gear, small spur gear, worm gear, and worm wheel to be selectable and replaceable as needed. This allows for adjustable transmission ratio and direction between the input and output shafts, enabling optimization of steering sensitivity, return-to-center characteristics, and handling force based on the vehicle's overall weight, front axle load, wheelbase, and desired steering feel. This invention achieves unidirectional control and external force isolation of steering force flow within a purely mechanical architecture without the need for hydraulic or electronic actuators. It is applicable to two-wheeled, three-wheeled, or four-wheeled vehicles, as well as other vehicles with front wheels or steering wheel mechanisms. It offers comprehensive advantages including strong structural versatility, low modification threshold, controllable manufacturing costs, and high value for widespread application. Attached Figure Description

[0034] Figure 1 This is a schematic diagram of the internal structure of a reverse transmission device for a vehicle and its control system according to the present invention.

[0035] Figure 2 This is a cross-sectional view of a reverse transmission device for a vehicle and its control system according to the present invention.

[0036] Figure 3 This is an assembly diagram of a reverse transmission device for a vehicle and its control system according to the present invention.

[0037] In the diagram: 1. Input shaft; 2. Coaxial cable; 3. Output shaft; 4. Large bevel gear; 5. Small bevel gear; 6. Large spur gear; 7. Small spur gear; 8. Worm gear; 9. Worm wheel; 10. Axle box; 11. First three-star platform; 12. Second three-star platform; 13. Frame. Detailed Implementation

[0038] Example 1

[0039] like Figure 1-3 ,

[0040] This embodiment provides a reverse-clutch transmission device for a vehicle, installed on a vehicle with a front-wheel steering mechanism, used to connect the steering wheel for steering to the steering structure of the front wheels. The reverse-clutch transmission device includes an input shaft 1, a coaxial coupling 2, an output shaft 3, a large bevel gear 4, a small bevel gear 5, a large spur gear 6, a small spur gear 7, a worm gear 8, a worm wheel 9, an axle box 10, a first three-star platform 11, a second three-star platform 12, and a frame 13. The input shaft 1 is fixedly connected to the first three-star platform 11 for connection to the steering wheel or handlebars; the output shaft 3 is fixedly connected to the second three-star platform 12 for connection to the steering structure of the front wheels; the axle box 10 is a hollow shell structure with an internal mounting cavity for accommodating the bevel gear pair, spur gear pair, and worm wheel pair; the outer periphery of the axle box 10 has mounting surfaces and mounting holes for connection to the frame 13; the axle box 10 is fixed to the frame 13 by bolts, ensuring that the axes of the input shaft 1 and the output shaft 3 coincide with the steering kingpin axis of the vehicle.

[0041] In this embodiment, the large bevel gear 4 is fitted and fixed on the input shaft 1, with its axis aligned with the axis of the input shaft 1. The small bevel gear 5 is coaxially fixed with the large spur gear 6, the large spur gear 6 meshes with the small spur gear 7, and the small spur gear 7 is coaxially fixed with the worm gear 8, forming a combined structure of two-stage spur gear transmission and worm gear transmission. Specifically, the small bevel gear 5 and the large spur gear 6 are mounted on an intermediate transmission shaft, which is supported and rotatable by rolling bearings within the shaft housing 10. The small spur gear 7 and the worm gear 8 are mounted on another intermediate transmission shaft, which is also supported and rotatable by rolling bearings. The small bevel gear 5 meshes with the large bevel gear 4 to change the direction of the torque transmitted axially along the input shaft 1 and transmit it to the intermediate transmission shaft. The large spur gear 6 meshes with the small spur gear 7 to achieve the second-stage speed change transmission and transmit power to the worm gear 8. The worm gear 8 meshes with the worm wheel 9, which is fixedly connected to the output shaft 3. The rotation of the worm wheel 9 directly drives the output shaft 3 to rotate around its axis. With the above settings, in the forward transmission condition where the worm 8 is the active component and the worm wheel 9 is the driven component, the input shaft 1 drives the output shaft 3 sequentially via the bevel gear pair, the spur gear pair, and the worm wheel and worm pair, forming a complete forward transmission chain. When the worm wheel 9 attempts to drive the worm 8 in the reverse direction, the worm 8 and the worm wheel 9 satisfy the self-locking condition, and the reverse transmission is blocked, thereby realizing the reverse transmission of the output shaft 3 relative to the input shaft 1.

[0042] In this embodiment, the input shaft 1 and the output shaft 3 are arranged coaxially in the axial direction via a coaxial connector 2. The coaxial connector 2 is disposed inside or above the shaft housing 10 to ensure the coaxiality of the input shaft 1 and the output shaft 3, and structurally eliminates the rigid integral shaft structure between the two shafts. Preferably, the coaxial connector 2 is a sleeve type or spline connection type structure, connected to the input shaft 1 and the output shaft 3 respectively, ensuring good torque transmission and coaxiality. This allows the input shaft 1 and the output shaft 3 to absorb small axial displacements, radial displacements, or angular deviations within a specified range, improving the overall assembly tolerance and impact resistance, and avoiding jamming and premature failure caused by load fluctuations or assembly errors.

[0043] In this embodiment, the large bevel gear 4 and the small bevel gear 5 constitute a bevel gear pair. The axial angle of the bevel gear pair is approximately 90°. The module, number of teeth, and pressure angle of the large bevel gear 4 and the small bevel gear 5 are selected according to conventional bevel gear design methods, enabling the bevel gear pair to convert the torque transmitted along the axis of the input shaft 1 into torque along the axis of the intermediate transmission shaft. The large spur gear 6 and the small spur gear 7 constitute a spur gear pair. The module, number of teeth, and tooth width of the spur gear pair are selected according to the target transmission ratio and strength requirements, used to achieve one or more stages of speed-up or speed-down transmission. The worm 8 and the worm wheel 9 constitute a worm gear pair. The number of worm threads and the normal module m are... nThe lead angle λ and the number of teeth on the worm gear are selected according to the self-locking design principle of worm gears, so that when the worm gear 9 attempts to drive the worm 8, the worm 8 and the worm gear 9 are in a self-locking state, and effective reverse transmission cannot be achieved. Those skilled in the art can determine the module, number of teeth, and number of starts of the above-mentioned gears and worm gears at each stage based on the vehicle weight, front wheel axle load, desired steering feel, and layout space, thereby obtaining transmission parameters that meet the strength, lifespan, and self-locking conditions.

[0044] In this embodiment, the axle box 10 is provided with several bearing mounting holes and stepped holes. The input shaft 1, intermediate drive shaft, and worm shaft are supported in the axle box 10 by rolling bearings. The output shaft 3 is installed in a bearing seat at the lower end or side of the axle box 10 by rolling bearings and / or tapered bearings. Preferably, rolling bearings conforming to standards such as GB / T 297, GB / T 276, and GB / T 283 can be used as support bearings for the input shaft 1, intermediate drive shaft, and worm shaft. Tapered bearing threaded flanges, lock nuts, and retaining rings are provided at the shaft ends to achieve axial preload. Oil seals and sealing end caps are provided on the outside of the bearings to prevent lubricating oil leakage and to prevent external dust and moisture from entering the axle box 10. The axle box 10 can be filled with grease or lubricating oil, and the lubricating medium can be replenished and replaced through the oil filling hole, oil drain hole, and vent hole on the box body. Those skilled in the art can select and replace the rolling bearings, seals, and fasteners shown in the parts list.

[0045] In this embodiment, the first three-star platform 11 is located at the end of the input shaft 1 away from the bevel gear pair. The three legs or mounting holes of the first three-star platform 11 are used for fixed connection with the steering wheel or handle. The first three-star platform 11 is fixed to the input shaft 1 via a key connection, spline connection, or interference fit. A steering shaft locking nut is provided on the input shaft 1 for axially locking the first three-star platform 11. The second three-star platform 12 is located at the end of the output shaft 3 away from the worm gear 9. The structure of the second three-star platform 12 matches the front wheel steering structure of the vehicle and can be fixedly connected to the front fork, steering knuckle, or other steering structure components via bolts, pins, or clamping structures, thereby realizing torque transmission between the output shaft 3 and the front wheel steering structure. The axle box 10 is connected to the frame 13 via a triangular bracket or mounting lug on the box body, forming a rigid installation to ensure the stability of the reverse transmission device during vehicle operation.

[0046] In use, the operator rotates the steering wheel or handle by turning the first three-star platform 11 connected to the input shaft 1, causing the input shaft 1 to rotate clockwise or counterclockwise around its axis. The input shaft 1 drives the large bevel gear 4, which is fixedly connected to it, to rotate. The large bevel gear 4 meshes with the small bevel gear 5. The small bevel gear 5 is coaxially fixed with the large straight gear 6 and drives the large straight gear 6 to rotate. The large straight gear 6 meshes with the small straight gear 7. The small straight gear 7 is coaxially fixed with the worm gear 8 and drives the worm gear 8 to rotate. The worm gear 8 meshes with the worm wheel 9. The worm wheel 9 is fixedly connected to the output shaft 3. In the forward transmission state where the worm gear 8 is the active force and the worm wheel 9 is the driven force, the output shaft 3 rotates clockwise or counterclockwise synchronously with the input shaft 1. The rotational torque is transmitted to the wheel steering structure through the second three-star platform 12 set at one end of the output shaft 3, realizing the normal steering of the front wheels of the vehicle.

[0047] During vehicle operation, when external forces such as uneven road surface, crosswinds, or changes in adhesion conditions act on the second three-star platform 12 through the wheels and its steering structure, and the second three-star platform 12 drives the output shaft 3 and worm gear 9 to passively rotate, the worm gear 9 attempts to drive the small spur gear 7, large spur gear 6, small bevel gear 5, large bevel gear 4, and input shaft 1 in the opposite direction through the worm 8 meshing with it. However, in the reverse transmission state where the worm gear 9 is active and the worm 8 is driven, the worm 8 and the worm gear 9 meet the self-locking condition, and the worm gear 9 has difficulty effectively driving the worm 8 to rotate, thereby preventing the above-mentioned gear transmission chain and input shaft 1 from being driven in the opposite direction. This achieves reverse transmission of the output shaft 3 relative to the input shaft 1, reduces the back transmission of external forces from the wheel side to the steering wheel or handle side, and improves the stability and safety of steering operation.

[0048] The materials used for the components described in this embodiment can be medium carbon steel, alloy steel, or other commonly used structural materials suitable for gear shaft parts. The gear tooth surfaces can be improved by tempering followed by high-frequency quenching or carburizing followed by grinding to enhance load-bearing capacity and wear resistance. Simultaneously, an appropriate precision grade is selected to ensure smooth transmission. Those skilled in the art, without altering the core concept of this invention, can appropriately adjust and optimize the bevel gear module, spur gear module, worm gear parameters, bearing type, and lubrication method based on the vehicle dimensions, installation space, and target performance; all such adjustments fall within the scope of protection of this invention.

[0049] Example 2

[0050] Based on the backstop transmission device for vehicles described in Embodiment 1, this embodiment addresses the lack of online monitoring and fault early warning during long-term operation of the backstop transmission device in Embodiment 1 by providing a method for monitoring the operating status and providing fault early warning for the backstop transmission device for vehicles. By adding sensors and an electronic control unit, key operating parameters of the backstop transmission device are collected in real time and processed by algorithms, enabling online diagnosis and fault early warning of the worm gear meshing state, axle box lubrication, and gear wear degree. Those skilled in the art can implement this method.

[0051] Therefore, based on the structure of Embodiment 1, the following are further provided: an input shaft angular velocity sensor installed on the input shaft 1 to detect the angular velocity ω1 of the input shaft 1; an output shaft angular velocity sensor installed on the output shaft 3 to detect the angular velocity ω2 of the output shaft 3; and a shaft box temperature sensor installed on the wall of the shaft box 10 or near the bearing seat to detect the internal temperature T of the shaft box. box A vibration sensor mounted on the outer surface of the axle box 10 is used to detect the vibration acceleration at the axle box and calculate the vibration characteristic quantity V. rms Alternatively, an encoder or angle sensor can be installed on input shaft 1 or output shaft 3 to count the cumulative number of working cycles N of the backstop transmission device. cyc The output signals of the aforementioned sensors are connected to the Electronic Control Unit (ECU). The ECU has a built-in memory and processor, which is used to execute the status monitoring and fault warning algorithm of this embodiment. The output of the ECU is connected to an audible and visual alarm unit to issue warning information to the driver or maintenance personnel.

[0052] Specifically, the steps include the following:

[0053] S1. When the vehicle is in normal use, the electronic control unit (ECU) collects the angular velocity ω1 of the input shaft (1) from the input shaft angular velocity sensor, the angular velocity ω2 of the output shaft 3 from the output shaft angular velocity sensor, and the axle box temperature T from the axle box temperature sensor according to the preset sampling period. box The vibration acceleration signal a(t) at the axle box 10 is collected from the vibration sensor, and the cumulative working cycle N of the reverse stop transmission device is obtained by counting and statistically analyzing the rotation angle signal. cyc The above data collection process can be automatically started after the vehicle is ignited and automatically stopped after the vehicle is turned off. The collected data can be stored in the ECU or an external storage medium for analysis as needed.

[0054] S2 and ECU filter and denoise the angular velocity and vibration signals collected in S1, for example, by using a low-pass filter or band-pass filter to suppress high-frequency noise and power frequency interference; at the same time, they calculate the actual instantaneous transmission ratio based on the input shaft angular velocity ω1 and the output shaft angular velocity ω2.

[0055]

[0056] The instantaneous transmission ratio deviation is then compared with the designed transmission ratio i0 to obtain the instantaneous transmission ratio deviation. ; Calculate the root mean square value V of the vibration acceleration signal a(t) within a preset time window. rms These parameters are used to characterize the vibration intensity at axle box 10. After processing via S2, filtered ω1, ω2, and T are obtained. box V rms and cumulative work cycles N cycThe parameters provide a basis for subsequent state evaluation.

[0057] S3. Define the instantaneous transmission ratio deviation Δi as the first key parameter a characterizing the rigidity and clearance state of the worm gear and gear transmission chain; define the axle box temperature T as... box Defined as the second key parameter b characterizing lubrication and thermal conditions; the vibration characteristic quantity V rms Defined as the third key parameter c characterizing meshing smoothness and bearing operating conditions; the cumulative number of working cycles N cyc Defined as the fourth key parameter d, characterizing the degree of lifespan consumption. For ease of comparison and normalization, the ECU can obtain corresponding baseline values, including the transmission ratio deviation baseline a, at the initial stage of vehicle installation or after maintenance. ref (Ideally close to 0), axle box temperature reference b ref (e.g., upper limit of normal operating temperature), vibration characteristic value reference c) ref (e.g., the average value under new equipment operating conditions) and the baseline number of cycles d ref (For example, the number of cycles corresponding to the design life), and store the above benchmark value in the calibration parameter area of ​​the ECU.

[0058] S4. Introducing the first key parameter a, the second key parameter b, and the third key parameter c, a first state evaluation parameter X is constructed to evaluate the current instantaneous operating condition of the backstop transmission. Specifically, the ECU calculates X according to the following relationship:

[0059]

[0060] Among them, k1, k2, and k3 are weighting coefficients, which are determined by calibration; This means when b > b ref Time to take When b ≤ b ref The value is set to 0. This functional relationship normalizes the instantaneous transmission ratio deviation |a| to reflect changes in the meshing stiffness and abnormal clearance of the worm gear and gears. It also incorporates the excessive portion of the axle box temperature relative to the reference and the vibration characteristic quantity c to reflect thermal-vibration anomalies caused by lubrication deterioration, tooth surface wear, or bearing damage. Therefore, X serves as a comprehensive evaluation quantity for the current instantaneous operating state of the backstop transmission device; a larger value indicates a greater deviation from the normal state.

[0061] S5. Introduce parameters a, b, and d to construct a second state evaluation parameter Y for assessing the long-term lifespan consumption and cumulative fatigue level of the backstop transmission. The ECU can calculate Y based on historical data within a certain time window, according to the following relationship:

[0062]

[0063] Where m1, m2, and m3 are weighting coefficients; The moving average of |a| within a preset time window is used to characterize the average degree of deviation of the transmission ratio over a period of time. The average time value of the portion of the axle box temperature exceeding the limit, used to characterize the impact of long-term overheating on lubrication and material properties; d / d ref This represents the utilization rate of the cumulative working cycles relative to the design life. Through this functional relationship, Y comprehensively reflects the life consumption status of the backstop transmission device due to wear, fatigue, and lubrication deterioration during long-term operation, providing a gradual change criterion for fault early warning.

[0064] S6. Introducing the instantaneous state evaluation parameter X obtained from S4 and the life consumption evaluation parameter Y obtained from S5, a comprehensive risk evaluation parameter R is constructed, and fault early warning is achieved based on this parameter. The ECU can calculate R according to the following relationship:

[0065]

[0066] Where w1 and w2 are weighting coefficients, X lim Y lim R represents the upper limit of the condition evaluation determined by testing or calibration. R characterizes the overall risk level of the backstop transmission. The ECU determines the warning level based on the relationship between R and a preset threshold. For example, when R < R1, the device is considered to be in normal condition; when R1 ≤ R < R2, a level one warning is issued, indicating that the axle box lubrication and tightness should be checked during routine maintenance; when R ≥ R2, a level two warning or fault alarm is issued, indicating that the backstop transmission may have severe wear, decreased self-locking performance, or abnormal meshing, requiring timely repair or replacement. In practice, the ECU can display alarm information in the driver's cabin via an audible and visual alarm unit, or write the fault code into the vehicle diagnostic system for maintenance personnel to read and trace.

[0067] Building upon Embodiment 1, this invention introduces an operational status monitoring and fault early warning mechanism through Embodiment 2. Instead of passively relying on a fixed gear ratio and the self-locking characteristics of the worm gear to perform the backstop function, it constructs a two-level state evaluation system and a comprehensive risk evaluation system based on multiple physical quantities such as transmission ratio deviation, axle box temperature, vibration intensity, and cumulative working cycles. This achieves joint monitoring of the instantaneous operating condition and long-term lifespan status of the backstop transmission device. Compared to conventional monitoring schemes that only observe a single temperature or vibration signal, this invention establishes a parameter combination and mapping relationship with clear mathematical relationships within the electronic control unit. This abstracts the working state of the mechanical structure into quantifiable and gradable risk indicators, providing a solid quantitative foundation for subsequent fault early warning.

[0068] This invention normalizes the transmission ratio deviation, which characterizes the changes in meshing stiffness and clearance, with temperature exceedances, which characterize lubrication and thermal conditions, and vibration characteristics, which characterize meshing smoothness and bearing conditions. These are then combined using the same evaluation function. This ensures that even a slight anomaly in any single parameter can be amplified into a perceptible state shift when combined with other parameters. Simultaneously, the instantaneous shift is interleaved with the cumulative number of working cycles over time, forming a second state evaluation quantity oriented towards lifespan depletion. This considers both the severity of the current operating conditions and the cumulative impact of historical conditions. This method of parameter interleaving and correlation evaluation across different physical quantities and time scales enables the invention to identify early failure modes that are difficult to reveal with a single parameter, avoiding the hysteresis and blind spots of traditional single-threshold, single-parameter monitoring schemes.

[0069] Building upon the aforementioned two-level state evaluation, this invention further integrates the instantaneous state with the lifespan consumption state through a comprehensive risk assessment, establishing a correspondence with graded early warning thresholds. This quantifies and grades the risk level of the backstop transmission device from an engineering perspective. It can issue mandatory fault alarms not only in the event of severe anomalies but also mild warnings when the risk is still on the rise, guiding maintenance personnel to proactively check lubrication, fastening, and component wear. Since the mechanical backstop structure itself remains unchanged, but rather, through the aforementioned multi-parameter integration and function mapping, online diagnosis and prediction of backstop performance degradation are achieved at the system level. Therefore, this invention achieves the technical effect of proactive management and forward-looking control of backstop function safety while maintaining the original structural simplicity.

Claims

1. A reverse-stop transmission device for a vehicle, characterized in that, include: Input shaft (1), output shaft (3), transmission mechanism and backstop mechanism; The transmission mechanism is used to transmit the rotation of the input shaft to the output shaft and change its transmission direction. The backstop mechanism is used to achieve backstop between the input shaft and the output shaft under the action of external force, and prevent the transmission of reverse rotation torque. The transmission mechanism includes a large bevel gear (4), a small bevel gear (5), a large straight gear (6), a small straight gear (7), a worm (8), and a worm wheel (9); The large bevel gear (4) is fixedly connected to the input shaft (1) and meshes with the small bevel gear (5). The small bevel gear (5) is coaxially fixed with the large straight gear (6). The large straight gear (6) meshes with the small straight gear (7). The small straight gear (7) is coaxially fixed with the worm (8). The worm (8) meshes with the worm wheel (9). The worm wheel (9) is fixedly connected to the output shaft (3). The reverse stop mechanism includes a worm (8) meshing with a worm wheel (9), which prevents the transmission of reverse torque through a self-locking effect, thereby realizing the reverse stop transmission of the output shaft (3) relative to the input shaft (1); In the forward transmission state where the worm (8) drives the worm wheel (9), the clockwise or counterclockwise rotation of the input shaft (1) is transmitted to the output shaft (3) via the large bevel gear (4), small bevel gear (5), large straight gear (6), small straight gear (7), worm (8), and worm wheel (9), causing the output shaft (3) to rotate synchronously clockwise or counterclockwise. When the external force generated by the vehicle's driving condition acts on the worm wheel (9) through the output shaft (3) in an attempt to reverse drive the worm (8), the self-locking effect between the worm (8) and the worm wheel (9) prevents the worm (8), the large straight gear (6), small straight gear (7), small bevel gear (5), large bevel gear (4), and input shaft (1) from being reverse driven, thereby achieving reverse transmission for the output shaft (3). It also includes a coaxial connector (2), through which the input shaft (1) and the output shaft (3) are arranged coaxially in the axial direction. The coaxial connector (2) is used to maintain the coaxiality of the input shaft (1) and the output shaft (3) and to cut off the rigid connection between the input shaft (1) and the output shaft (3). The large bevel gear (4) and the small bevel gear (5) form a bevel gear pair that changes the transmission direction, which is used to convert the rotational torque transmitted along the input shaft (1) into the transmission torque in the plane where the large spur gear (6) and the small spur gear (7) are located, so that the large bevel gear (4), the small bevel gear (5), the large spur gear (6), the small spur gear (7), the worm (8) and the worm wheel (9) form a three-dimensional spatial transmission structure; It also includes a shaft box (10), in which the large bevel gear (4), small bevel gear (5), large straight gear (6), small straight gear (7), worm (8) and worm wheel (9) are all installed, and the input shaft (1) and the output shaft (3) pass through the shaft box (10); One end of the input shaft (1) is equipped with a first three-star platform (11), and one end of the output shaft (3) is equipped with a second three-star platform (12). The first three-star platform (11) is used to connect with the steering wheel for steering, and the second three-star platform (12) is used to connect with the steering structure of the wheel for steering. The axle box (10) is mounted on the vehicle via the frame (13). The input shaft (1) can rotate clockwise or counterclockwise around its axis under the action of external operating force and drive the output shaft (3) to rotate clockwise or counterclockwise synchronously through the large bevel gear (4), small bevel gear (5), large straight gear (6), small straight gear (7), worm (8) and worm wheel (9). However, when external force is applied to the output shaft (3) through the wheel and the second triangular platform (12), the output shaft (3) cannot drive the input shaft (1) in the opposite direction through the worm wheel (9), worm (8), small straight gear (7), large straight gear (6), small bevel gear (5) and large bevel gear (4). The vehicle has a steering mechanism that steers by means of wheels. The input shaft (1) is connected to a steering wheel for manipulating the steering via the first three-star platform (11), and the output shaft (3) is connected to the wheel steering structure in the steering mechanism via the second three-star platform (12) to form the steering device of the vehicle.

2. The reverse-stop transmission device for a vehicle according to claim 1, characterized in that, The module, number of teeth, and number of heads of the large bevel gear (4), small bevel gear (5), large straight gear (6), small straight gear (7), worm (8), and worm wheel (9) can be selected and replaced as needed to adjust the transmission speed ratio and transmission direction between the input shaft (1) and the output shaft (3).

3. A control system for a reverse transmission device for a vehicle, characterized in that: The vehicle reverse transmission device as described in any one of claims 1-2 further includes: an input shaft angular velocity sensor mounted on the input shaft (1) for detecting the angular velocity of the input shaft (1); an output shaft angular velocity sensor mounted on the output shaft (3) for detecting the angular velocity of the output shaft (3); an axle box temperature sensor mounted on the wall of the axle box (10) for detecting the internal temperature of the axle box; a vibration sensor mounted on the outer surface of the axle box (10) for detecting the vibration acceleration at the axle box and calculating the vibration characteristic quantity; an encoder is set on the input shaft (1) or the output shaft (3) for counting the cumulative working cycles of the reverse transmission device; the output signal is connected to the electronic control unit, which has a built-in memory and processor for executing the status monitoring and fault warning algorithm; the output terminal of the electronic control unit is connected to the audible and visual alarm unit for issuing warning information to the driver or maintenance personnel. The condition monitoring and fault early warning algorithm includes the following steps: S1. When the vehicle is in normal use, the electronic control unit (ECU) collects the angular velocity of the input shaft (1) from the input shaft angular velocity sensor according to the preset sampling period. The angular velocity of the output shaft (3) is collected from the output shaft angular velocity sensor. The axle box temperature T is collected from the axle box temperature sensor. box The vibration acceleration signal a(t) at the axle box (10) is collected from the vibration sensor, and the cumulative working cycle N of the reverse stop transmission device is obtained by counting and statistically analyzing the rotation angle signal. cyc The above data collection process starts automatically after the vehicle is ignited and stops automatically after the vehicle is turned off. The collected data is stored in the electronic control unit (ECU) or an external storage medium for analysis as needed. S2, the Electronic Control Unit (ECU) filters and denoises the angular velocity and vibration signals acquired in S1; simultaneously, based on the input shaft angular velocity... With output shaft angular velocity Calculate the actual instantaneous transmission ratio; The instantaneous transmission ratio deviation is then compared with the designed transmission ratio i0 to obtain the instantaneous transmission ratio deviation. ; Calculate the root mean square value V of the vibration acceleration signal a(t) within a preset time window. rms The vibration intensity at the axle box (10) is used to characterize the vibration intensity; after processing by S2, the filtered value is obtained. , T box V rms and cumulative work cycles N cyc The parameters provide a basis for subsequent state evaluation; S3. Define the instantaneous transmission ratio deviation Δi as the first key parameter a characterizing the rigidity and clearance of the worm gear and gear transmission chain; define the axle box temperature T as... box Defined as the second key parameter b characterizing lubrication and thermal conditions; the vibration characteristic quantity V rms Defined as the third key parameter c characterizing meshing smoothness and bearing operating conditions; the cumulative number of working cycles N cyc Defined as the fourth key parameter d characterizing the degree of lifespan consumption; for ease of comparison and normalization, the electronic control unit (ECU) obtains corresponding baseline values, including the transmission ratio deviation baseline a, at the initial stage of vehicle installation or after maintenance. ref Axle box temperature reference b ref Vibration characteristic value reference c ref and the baseline for the number of cycles d ref The aforementioned reference values ​​are then stored in the calibration parameter area of ​​the electronic control unit (ECU). S4. Introducing the first key parameter a, the second key parameter b, and the third key parameter c, a first state evaluation parameter X is constructed to evaluate the current instantaneous operating condition of the backstop transmission device; specifically, the electronic control unit (ECU) calculates X according to the following relationship: in, , , These are weighting coefficients, determined by calibration; Indicates when Time to take ,when When the value is 0, the instantaneous transmission ratio deviation |a| is normalized through this function to reflect the changes in the meshing stiffness and clearance abnormalities of the worm gear and gears. On the other hand, the excessive part of the axle box temperature relative to the reference and the vibration characteristic quantity are taken into consideration to reflect the thermal-vibration abnormalities caused by lubrication deterioration, tooth surface wear or bearing damage. Thus, X serves as a comprehensive evaluation quantity for the current instantaneous operating state of the reverse stop transmission device. The larger the value, the greater the degree to which the device deviates from the normal state. S5. Introduce parameters a, b, and d to construct a second state evaluation parameter Y for evaluating the long-term lifespan consumption and cumulative fatigue level of the backstop transmission device; the electronic control unit (ECU) calculates Y based on historical data within a certain time window according to the following relationship: in, , , These are weighting coefficients; The moving average of |a| within a preset time window is used to characterize the average degree of deviation of the transmission ratio over a period of time. The average time value of the portion of the axle box temperature exceeding the limit, used to characterize the impact of long-term overheating on lubrication and material properties; d / d ref Y represents the utilization rate of the cumulative working cycle number relative to the design life. Through this functional relationship, Y comprehensively reflects the life consumption state of the backstop transmission device due to wear, fatigue and lubrication deterioration during long-term operation, providing a gradual change criterion for fault early warning. S6. Introduce the instantaneous state evaluation parameter X obtained from S4 and the life consumption evaluation parameter Y obtained from S5 to construct the comprehensive risk evaluation parameter R, and realize fault early warning based on it; the electronic control unit (ECU) calculates R according to the following relationship: Among them, among them, , X is the weighting coefficient. lim Y lim The upper limit of the condition evaluation is determined based on tests or calibrations; R is used to characterize the overall risk level of the backstop transmission device. The electronic control unit (ECU) determines the warning level based on the relationship between R and a preset threshold. The device is considered to be in normal condition at this time; when A level one warning is issued, indicating that the lubrication and tightness of the axle box should be checked during routine maintenance; when The system will issue a level 2 warning or fault alarm, indicating that the backstop transmission may have serious wear, reduced self-locking performance, or abnormal meshing, requiring timely inspection or replacement; the electronic control unit (ECU) will display alarm information in the cabin through the audible and visual alarm unit, or write the fault code into the vehicle diagnostic system so that maintenance personnel can read and track it.

Images