Cable Steering Assembly for Riding Mower Tight Turns
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Riding lawn mowers often experience steering responsiveness issues due to slack or play in the steering assembly, which affects the quality of the steering experience and can lead to wheel slippage during turns.
Innovation Solution
A cable system with guide pulleys and a turn magnification assembly that approximates Ackermann geometry steering, providing a tighter coupling between the steering wheel and front wheels by using a cable wrapped around a steering shaft and indirectly coupled to rotatable cams and steering knuckles via linkage members, enhancing the mechanical advantage of cam rotation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a traditional steering assembly with direct coupling is used, then the steering structure is simple, but steering responsiveness deteriorates due to slack or play in the coupling
Solution Approach 1:
A cable system is introduced as an intermediary element between the steering wheel and front wheels. The cable wraps around a steering shaft and connects to turn magnification assemblies at each wheel, providing a flexible coupling that eliminates slack while maintaining structural simplicity. This intermediary cable transmission mechanism resolves the contradiction by achieving responsive steering without rigid direct coupling.
2Ease of operation
If a cable system with turn magnification assembly is used, then steering responsiveness improves, but the device complexity increases
Solution Approach 1:
The turn magnification assembly incorporates a cam mechanism that dynamically adjusts the steering angle based on cable tension and wheel position. The cam profile varies the mechanical advantage during the steering rotation, providing magnification at certain angles and direct coupling at others. This dynamic adjustment optimizes steering control precision while managing the complexity through a single adjustable mechanism per wheel.
3Reliability
If Ackermann geometry steering is implemented, then wheel slippage during turns is reduced, but the steering mechanism complexity increases
Solution Approach 1:
The turn magnification assembly creates asymmetric steering angles for the left and right front wheels through the cam mechanism. During a turn, one wheel receives magnified steering input while the other receives reduced input, approximating Ackermann geometry. This asymmetric distribution of steering angles eliminates wheel slippage by ensuring both wheels rotate around a common center point, achieving proper turn geometry without complex linkage systems.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This solution improves steering responsiveness and reduces slack, allowing for sharper turns without wheel slippage, enhancing the overall steering feel and quality of the riding lawn mower.
Implementation Method 1
The cable is wrapped around a portion of a steering shaft operably coupled to the steering apparatus. The cable terminates at respective ends thereof at corresponding portions of a turn magnification assembly that indirectly couples the cable to the front wheels.
Implementation Method 2
The at least one set of guide pulleys receives respective different portions of the cable to guide the cable to respective ones of the first and second shaped cams.
Data Source
AI summary
A riding yard maintenance vehicle may include a frame, a steering assembly, and a cable. Wheels of the riding yard maintenance vehicle may be attachable to the frame. The steering assembly may include a steering apparatus operably coupled to front wheels of the riding yard maintenance vehicle via a cable system. The cable system may include the cable, which may be wrapped around at least a portion of the steering shaft. The cable may terminate at respective ends thereof at corresponding portions of a turn magnification assembly that indirectly couples the cable to the front wheels. The turn magnification assembly may be configured to approximate Ackermann geometry steering of respective ones of the front wheels based on movement of the cable responsive to rotation of the steering shaft.