Progressive Elastomeric Load Cushion for Heavy Haul Suspension
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Solution Overview
Problem
Prior elastomeric spring suspensions for vocational or heavy haul truck applications face issues with ride quality and roll stability due to abrupt changes in spring rate caused by engagement or disengagement of auxiliary springs, leading to frequent loading and unloading, which compromises ride quality and results in tensile loading that can cause elastomer breakdown.
Innovation Solution
A vehicle suspension system with a continuously increasing spring rate, achieved through the use of shear springs and progressive spring rate load cushions, which eliminate tensile loading and provide improved durability by reducing the number of fasteners and mechanical joints, ensuring good ride quality without sacrificing roll stability across varying loads.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If auxiliary springs are engaged or disengaged to achieve variable spring rate, then the spring rate can be adjusted for different loads, but abrupt changes in spring rate occur causing frequent loading and unloading which compromises ride quality
Solution Approach 1:
The patent employs a progressive spring rate load cushion that provides a continuously increasing spring rate from light to heavy loads without abrupt changes. This eliminates the frequent engagement and disengagement of auxiliary springs, ensuring continuous and smooth suspension action across the entire load range, thereby maintaining ride quality while achieving variable spring rate adaptability
2Stability of the object's composition
If auxiliary springs are used to provide variable spring rate, then roll stability can be improved under heavy load, but tensile loading occurs which can cause elastomer breakdown
Solution Approach 1:
The patent removes auxiliary springs from the suspension system entirely, replacing them with a progressive spring rate load cushion that provides continuously increasing spring rate. This eliminates the tensile loading mechanism that causes elastomer breakdown while maintaining roll stability under heavy load through the progressive spring rate characteristic
3Stability of the object's composition
If single spring rate is used to provide roll stability, then roll stability is adequate, but ride quality is compromised due to fixed spring rate
Solution Approach 1:
The patent changes the spring rate parameter from a fixed value to a continuously increasing value through the progressive spring rate load cushion. This allows the suspension to provide adequate roll stability under heavy load while maintaining good ride quality under light load, effectively resolving the trade-off between these two performance characteristics
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
The solution provides a suspension system with a continuously increasing spring rate, minimizing interaxle brake load transfer and enhancing articulation, while maintaining ride quality and roll stability without abrupt changes in spring rate, thus reducing fatigue and improving durability.
Implementation Method 1
a first and second elastomeric spring cushion portions, respectively, bonded to the top side and bottom side of the rate plate
Implementation Method 2
Two non-tensile loading shear springs are provided in each opening
Data Source
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AI summary
A progressive spring rate elastomeric load cushion having a pyramidal shaped cushion portion with a flattened top surface and a base plate to which the cushion portion is bonded. With this shape the load cushion has a continuously increasing spring rate as a load that is applied perpendicular to the base of the load cushion is increased. First and second ears extend outwardly from opposite edges of the base and comprise first and second through-holes through which a fastener may be inserted in order to retain the load cushion in a suspension.