Gas Spring End Member Design for Compact Ride Comfort

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Solution Overview

Problem

Existing gas spring devices face challenges in achieving low spring rates for improved ride comfort while maintaining a compact size and efficient damping, as increasing gas volume leads to larger assemblies and resistance in gas flow through orifices or valve ports.

Innovation Solution

The design incorporates a gas spring assembly with end members featuring a flexible spring member and end member chambers in fluid communication, allowing for minimal fluid flow restriction and efficient damping, while maintaining a compact size through optimized fluid communication ports and securement features.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If the volume of pressurized gas is increased to reduce spring rate, then ride comfort is improved, but the overall size of the gas spring assembly increases

Engineering Contradiction:
Improveride comfortVSAvoidgas spring assembly size
Core Design Contradiction:
Ease of operationVSVolume of stationary object

Solution Approach 1:

The patent places the damping chamber inside the spring chamber, creating a nested configuration where the damping piston and chamber are contained within the spring volume. This allows the damping function to be added without increasing the overall external dimensions of the gas spring assembly, resolving the contradiction between improving ride comfort through additional gas volume and maintaining compact size.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If orifices or valve ports are used for gas flow, then damping is provided, but fluid flow resistance increases

Engineering Contradiction:
Improvedamping efficiencyVSAvoidfluid flow resistance
Core Design Contradiction:
ReliabilityVSLoss of energy

Solution Approach 1:

The patent provides different local flow characteristics at different locations: the damping piston includes multiple orifices for localized damping control, while the end member chamber provides a larger opening for minimal restriction flow. This local differentiation allows efficient damping where needed while minimizing overall fluid flow resistance.

Inventive Principle:
Principle #3Local quality

Solution Approach 2:

The gas flow path is segmented into multiple pathways: flow through the damping piston orifices for damping, and flow through the end member chamber opening for minimal restriction. This segmentation allows the system to achieve both damping and low resistance flow simultaneously by dividing the flow into different channels with different resistance characteristics.

Inventive Principle:
Principle #1Segmentation

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 configuration enhances ride comfort by reducing spring rate without increasing the size of the gas spring assembly and provides effective damping with minimal fluid flow restriction, improving the overall performance of suspension systems.

Implementation Method 1

a flexible spring member and an end member chamber in fluid communication with the spring chamber

Methodology Applied
Scientific EffectElasticity: Elasticity

Implementation Method 2

springs that utilize pressurized gas as the working medium of the devices

Methodology Applied
Scientific EffectCompression: Compression

Implementation Method 3

increasing the volume of pressurized gas operatively associated with the gas spring

Methodology Applied
Scientific EffectBoyle's Law: Boyle's Law

Implementation Method 4

the one or more damping elements can be of a type and kind that utilize gaseous fluid rather than liquid as the working medium

Methodology Applied
Scientific EffectViscous damping: Viscous Damping

Implementation Method 5

there is some resistance to the movement of pressurized gas through these passages or ports. This resistance acts to dissipate energy associated with gas springs and/or suspension systems

Methodology Applied
Scientific EffectPressure drop: Pressure Drop

Data Source

PatentEP3140137B1Gas spring end members as well as gas spring assemblies including same
Publication Date: 2021.04.14 FIRESTONE INDUSTRIAL PRODUCTS COMPANY LLC
  • EP3140137B1 patent drawingFigure 1
  • EP3140137B1 patent drawingFigure 2
  • EP3140137B1 patent drawingFigure 3

AI summary

A gas spring end member has an end member axis and is dimensioned for securement to an associated flexible spring member. The gas spring end member includes an end member wall with a base wall portion disposed transverse to the end member axis. An outer wall portion extends axially from along the base wall portion. A mounting wall portion is dimensioned to receivingly engage an associated end of the associated flexible spring member. An end wall portion extends peripherally about the end member axis and operatively connects the outer wall portion and the mounting wall portion to at least partially define an end member volume. An inner wall portion separates the end member volume into an end member reservoir disposed outward of the inner wall portion and an end member chamber disposed inward of the inner wall portion. Gas spring assemblies and suspensions systems are also included.