Work Vehicle Steering Axis Positioning for Reduced Scrub Radius
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Solution Overview
Problem
The existing work vehicles have a significant scrub radius between the steering axis and the width center of the steerable wheels, resulting in increased steering force, which hinders desirable steerability.
Innovation Solution
The work vehicle design includes a boss portion that supports the steerable wheels pivotally about a steering axis via a kingpin, with the kingpin extending in an L-shape between the steerable wheel and the boss portion, positioned closer to the width center, reducing the scrub radius and steering force. Additionally, the steerable wheels are set with a caster angle and kingpin angle for improved steerability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Stability of the object's composition
If the steering axis is positioned at the vehicle body inner lateral side end of the steerable wheel, then the structural stability is improved, but the scrub radius increases resulting in increased steering force
Solution Approach 1:
The boss portion is repositioned from the conventional lateral side end position to a position closer to the width center of the steerable wheel, representing a positional shift in the lateral dimension. This dimensional change reduces the scrub radius while maintaining structural stability through the optimized geometric relationship between the steering axis and wheel contact point.
Solution Approach 2:
The invention changes the key parameter of boss portion position along the width direction of the steerable wheel. By adjusting this positional parameter to be closer to the width center, the scrub radius is reduced, thereby decreasing the steering force while preserving the structural integrity provided by the boss portion configuration.
2Ease of operation
If the boss portion is positioned closer to the width center of the steerable wheel, then the steering force is reduced, but the structural support stability may be compromised
Solution Approach 1:
The boss portion position parameter is optimized to a specific location closer to the width center of the steerable wheel. This parameter change reduces the scrub radius and steering force while the boss portion's geometric design and connection structure maintain sufficient structural support stability for operational requirements.
Solution Approach 2:
The boss portion is designed with specific local structural characteristics at its connection points and geometry to provide adequate structural support. The local quality of the boss portion structure compensates for the reduced distance to the wheel center, ensuring that structural stability is maintained while achieving reduced steering force.
Data Source
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AI summary
A work vehicle includes a pair of left and right steerable wheels (2F), a pair of left and right drivable wheels (2B), and a boss portion (14a) that supports the steerable wheel (2F) pivotally about a steering axis (Z1) via a kingpin (15). The boss portion (14a) is closer to a width center (C) of the steerable wheel (2F) than a vehicle body inner lateral side end of the steerable wheel (2F).