Cross-Linked Steering Linkage for Sharp Turns Without Wheel Drag
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Solution Overview
Problem
Existing steering linkages and axles in vehicles, such as tractors and mowers, are limited by mechanical constraints that prevent sharp turns, often resulting in wheel drag, slipping, or sliding, and require inefficient multipoint maneuvers to change directions.
Innovation Solution
A cross-linked pivot assembly with a steering linkage and axle assembly that includes connectors and links, operable via a linear actuator, allowing wheels to rotate between positions at least 150-degrees apart, enabling efficient and sharp turns without wheel drag or slipping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If traditional steering linkages and axles are used, then the vehicle structure is simple and mechanically stable, but the turning radius is large and sharp turns are prevented
Solution Approach 1:
The steering linkage is divided into multiple independent links (first link, second link, third link, fourth link) that are pivotally connected in sequence. Each link can rotate independently about its pivot points, allowing the steering system to achieve complex wheel movements through simple rotational segments rather than requiring a complex monolithic structure.
Solution Approach 2:
The steering linkage incorporates vertical displacement of the wheel assembly by pivoting connections that allow movement in both horizontal (steering angle) and vertical dimensions. This multi-dimensional movement capability enables the wheel to achieve sharp turning angles and navigate obstacles that would be impossible with traditional planar steering mechanisms.
2Ease of operation
If the inside wheel is locked during a turn, then the turning radius decreases, but wheel drag and slipping occur
Solution Approach 1:
The steering linkage employs dynamic pivot connections that allow the wheel assembly to move freely through a wide range of angles (at least 150 degrees apart) without mechanical binding. The pivotal connections maintain constant contact and force distribution throughout the turning motion, eliminating wheel drag and slipping that occur in static or rigid steering systems.
Solution Approach 2:
The steering mechanism changes the geometric parameters of the wheel assembly during turning by varying the angles and positions of the linkage links. This dynamic parameter adjustment allows the wheel to maintain optimal contact with the ground throughout the turning motion, preventing slipping and dragging while achieving sharp turns.
3Ease of operation
If front wheels are steered all the way to the right or left, then the steering angle increases, but the front wheels are dragged and rear wheels slip or slide
Solution Approach 1:
The linkage maintains dynamic balance throughout the full steering range by allowing coordinated movement of all links. As the wheel steers to extreme angles, the pivotal connections automatically adjust the positions of the links to maintain proper wheel alignment and ground contact, preventing dragging and slipping even at maximum steering angles.
Solution Approach 2:
The series of pivotal connections act as intermediaries that transfer and distribute steering forces smoothly throughout the linkage system. Each pivot point serves as a mediator that reduces stress concentrations and distributes the mechanical loads evenly across all links, preventing the harmful effects of wheel drag and slipping that occur in rigid steering systems.
Data Source
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AI summary
A steering linkage for a vehicle includes a cross-linked pivot assembly which includes a first connector configured for connection with the axle, first and second links, and a second connector configured for connection with a wheel. The first connector has a first end with which a first end of the first link is pivotally connected and a second end with which a first end of the second link is pivotally connected. The second connector has first and second ends and is arranged in spaced relation from and at an angle relative to the first connector. The first end of the second connector is arranged closer to the second end of the first connector than is the second end of the second connector. A second end of the first link is pivotally connected with the first end of the second connector and a second end of the second link is pivotally connected with the second end of the second connector.