Steering Axle Drive Assembly for Scuff-Free Zero-Radius Turns
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Solution Overview
Problem
Existing zero radius turn vehicles and tractors face inefficiencies in completing sharp turns and zero-radius maneuvers due to mechanical limitations of traditional steer axles, leading to issues like wheel dragging, slipping, and scuffing, especially when attempting to change directions abruptly.
Innovation Solution
A steering axle drive assembly that independently controls wheels opposite the main drive wheels, allowing for rotation about vertical and horizontal axes, with a control mechanism that includes a joystick or steering wheel for direction input, and independently controlled brakes to facilitate precise steering and driving without passing through the origin.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Speed
If traditional steer axles are used with independent brakes on main drive wheels, then sharper turns can be achieved by slowing the inside wheel, but wheel scuffing occurs due to mechanical limits of traditional steer axles
Solution Approach 1:
The vehicle steering system is segmented into two independent axles: a front steering axle with wheels that rotate about vertical axes for steering, and a rear drive axle with wheels that rotate about horizontal axes for propulsion. This segmentation allows each axle to perform its specialized function without the mechanical constraints of traditional integrated steer axles, enabling sharp turns without wheel scuffing.
Solution Approach 2:
The invention adds a vertical axis rotation capability to the front steering wheels, creating a new degree of freedom. Instead of relying solely on horizontal plane steering limitations, the front wheels can now rotate vertically to achieve sharp directional changes, while the rear wheels provide independent drive force, eliminating the scuffing problem.
2Speed
If the inside wheel is locked during a turn, then the turning radius decreases, but the front wheels are dragged and the vehicle cannot complete a pivot turn due to geometric constraints of the front axle
Solution Approach 1:
The front steering axle wheels are designed with dynamic rotation capability about vertical axes, allowing them to adapt their orientation during turning maneuvers. This dynamic adjustment enables the front wheels to align properly during pivot turns, eliminating the dragging issue that occurs with static traditional steer axles and allowing complete pivot turn capability.
3Reliability
If steering wheels are mechanically steered by traditional steering wheel, then side slope performance benefits are achieved, but the wheels must rotate back to straight-ahead position before changing direction, making maneuvers like parallel parking tedious
Solution Approach 1:
The traditional mechanical steering system that requires wheels to return to a neutral straight-ahead position is replaced with an independent control system for each front wheel. Each wheel can be controlled individually to rotate about its vertical axis, allowing the vehicle to change direction without requiring the wheels to pass through a neutral position, thereby simplifying complex maneuvers like parallel parking while maintaining side slope performance.
Data Source
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AI summary
A steering axle drive assembly includes a steering axle having opposite ends, a wheel pivotally connected with each steering axle end, and a control mechanism. The wheels are operated by the control mechanism for rotation about a vertical axis and a horizontal axis. When the axle is connected with a vehicle, the control mechanism controls the steering axle wheels independent of other wheels of the vehicle, such as the main drive wheels, to steer and drive the vehicle from an origin in any direction without passing through the origin. Preferably, a motor or linear actuator controls the rotation of the steering axle wheels. The steering axle drive assembly can be further improved by including an angled axle.