Resilient Tie Rods for Vehicle Axle Impact Absorption

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Solution Overview

Problem

Rigid tie rods in vehicle steering axle assemblies are prone to damage, sub-optimal in absorbing impacts, increase weight and cost, and require frequent lubrication, limiting their performance and maintenance efficiency.

Innovation Solution

A resilient tie rod made of materials like aircraft-grade aluminum or spring steel, with a non-circular cross-section and non-rotatably secured to steering knuckles, allowing it to bend and self-center, reducing deformation and stress, and optimizing alignment and Ackerman steering configurations without additional components.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Strength

If a rigid tie rod is used, then structural strength and alignment stability are improved, but susceptibility to damage from obstacles and impact absorption are worsened

Engineering Contradiction:

Improvestructural strengthVSAvoidresistance to damage

Core Design Contradiction:

StrengthVSReliability

Solution Approach 1:

The tie rod transitions from a rigid structure to a flexible structure by changing the material parameter from rigid metal to flexible material (such as rubber or elastomer), enabling the tie rod to bend and flex upon impact while maintaining functional integrity and absorbing shock loads

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The flexible tie rod inherently provides cushioning before impact occurs by being pre-configured with elastic properties, allowing it to absorb impact energy through deformation rather than transmitting it directly to the steering components

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

2Stability of the object's composition

If a rigid tie rod is used, then alignment stability is improved, but impact absorption and stress reduction are worsened

Engineering Contradiction:

Improvealignment stabilityVSAvoidstress on interconnections

Core Design Contradiction:

Stability of the object's compositionVSStress or pressure

Solution Approach 1:

The tie rod material parameter is changed from rigid to flexible, enabling the tie rod to deform under impact loads and return to its original position, thereby absorbing impact energy and reducing stress transmission to steering knuckles and interconnections while maintaining alignment stability

Inventive Principle:

Principle #35Parameter changes

3Ease of operation

If ball joints are used to connect tie rod to steering knuckles, then rotational movement is improved, but lubrication requirements and maintenance costs are worsened

Engineering Contradiction:

Improverotational movementVSAvoidmaintenance costs

Core Design Contradiction:

Ease of operationVSEase of manufacture

Solution Approach 1:

The ball joint component is completely removed from the system by changing the tie rod material to flexible material that eliminates the need for rotational joints, thereby eliminating lubrication requirements and associated maintenance costs while still allowing the tie rod to move with the steering knuckles through elastic deformation

Inventive Principle:

Principle #2Taking out (Extraction)

4Reliability

If resilient material is used for tie rod, then impact absorption is improved, but rotational movement capability is worsened

Engineering Contradiction:

Improveimpact absorptionVSAvoidrotational movement

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The mechanical rotational joint system (ball joints) is replaced with a flexible material system that achieves movement through elastic deformation rather than mechanical rotation, thereby maintaining impact absorption capabilities while eliminating the need for rotational movement mechanisms

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 resilient tie rod resists deformation, reduces weight and maintenance costs, enhances performance by self-centering steering knuckles and optimizing alignment, and absorbs impacts effectively, improving vehicle handling and durability.

Implementation Method 1

The resilient material allows the Alumi-Flex Tie Rod to elastically flex upon coming into contact with an obstacle or otherwise being subjected to an impact

Methodology Applied

Scientific EffectElasticity: Elasticity

Data Source

PatentUS8246060B2Resilient tie rods and axle assemblies employing same

Publication Date: 2012.08.21 HENDRICKSON USA LLC

AI summary

A tie rod for a vehicle axle assembly is constructed using substantially compliant, flexible, and/or resilient material. Such a resilient tie rod may be provided with a rectangular or otherwise non-circular cross-section. Such a resilient tie rod may be used in combination with an axle assembly of the type having an axle and a steering knuckle rotatably associated with each end of the axle. The tie rod may be rotatably or non-rotatably secured to the steering knuckles.