Cylinder Shock Assembly Solid Float Air Spring

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Existing vehicle air suspension systems with flexible membranes have limited operating pressures and require additional mechanical components like anti-roll bars to achieve desired spring rates, which can be space-constrained and result in abrupt spring rate changes, leading to undesirable ride quality.

Innovation Solution

A cylinder shock assembly with a solid, non-expandable air cylinder float and a primary coil spring that operates at higher pressures, eliminating the need for auxiliary anti-roll devices and providing a continuously increasing spring rate without abrupt changes, by using a combination of higher air pressures and fluid management to adjust the effective spring rate.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Stress or pressure

If a flexible membrane air spring is used, then the strut can provide air suspension functionality, but the operating pressure is limited to 80-120 psi and the spring rate is relatively low

Engineering Contradiction:
Improveoperating pressureVSAvoidmembrane durability
Core Design Contradiction:
Stress or pressureVSReliability

Solution Approach 1:

The patent removes the flexible membrane component from the air spring system entirely. Instead of using a membrane-containing air spring, the invention uses a bellows assembly that is sealed within a housing, extracting the problematic flexible element while retaining the air suspension functionality. This allows operation at higher pressures without membrane durability limitations.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The patent replaces the flexible membrane mechanical system with a rigid housing and bellows assembly system. The bellows provides the necessary compliance and air volume changes, while the rigid housing contains the air at higher pressures without relying on flexible membrane integrity. This substitution enables higher operating pressures and improved reliability.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Force

If the effective spring rate is increased to improve handling and stability, then auxiliary anti-roll devices are eliminated, but the strut size increases beyond available space

Engineering Contradiction:
Improveeffective spring rateVSAvoidstrut volume
Core Design Contradiction:
ForceVSVolume of moving object

Solution Approach 1:

The patent changes the operating pressure parameter from 80-120 psi to 200-500 psi or higher. This parameter change allows the air spring to achieve the required effective spring rate and force output without increasing the physical dimensions of the strut, as the higher pressure compensates for the smaller volume.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent segments the air spring into distinct functional components: a bellows assembly for volume change, a housing for containment, and a piston-rod assembly for force transmission. This segmentation allows optimization of each component's size and function, achieving high spring rate in a compact overall package.

Inventive Principle:
Principle #1Segmentation

3Force

If a coil spring is added to increase effective spring rate, then the spring rate increases, but the strut requires larger diameter and volume

Engineering Contradiction:
Improveeffective spring rateVSAvoidstrut diameter
Core Design Contradiction:
ForceVSArea of stationary object

Solution Approach 1:

The patent changes the pressure parameter to 200-500 psi or higher, which allows the air spring to generate sufficient force and effective spring rate without requiring a larger diameter. The higher pressure compensates for the smaller cross-sectional area, eliminating the need for additional coil springs.

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The patent merges the spring function and air suspension function into a single integrated air spring assembly. The bellows assembly provides both the suspension compliance and the spring rate characteristics, eliminating the need for separate coil spring components that would increase diameter.

Inventive Principle:
Principle #5Merging (Combining)

4Force

If a bump stop is used in air spring with coil spring, then the spring rate increases at compression, but an abrupt change in spring rate causes jolt to vehicle

Engineering Contradiction:
Improvespring rateVSAvoidride smoothness
Core Design Contradiction:
ForceVSEase of operation

Solution Approach 1:

The patent employs a bellows assembly that dynamically changes its effective spring rate continuously as it compresses. The spring rate progresses smoothly from lower values at extension to higher values at compression, without abrupt transitions. This dynamic, continuous progression eliminates the jolting sensation caused by sudden spring rate changes in bump stop systems.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

Instead of using a bump stop to abruptly increase spring rate at compression (the conventional approach), the patent inverts the approach by designing the bellows assembly to naturally provide a continuously increasing spring rate throughout its compression stroke. The spring rate increase is built into the fundamental geometry and operation of the bellows itself, rather than being added by a separate bump stop mechanism.

Inventive Principle:
Principle #13The other way round (Inversion)

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 allows for higher effective spring rates within existing space constraints, enhancing vehicle handling, stability, and ride quality, while eliminating the need for auxiliary roll resisting devices and providing a more durable and cost-effective alternative to traditional air springs.

Implementation Method 1

When a load applied to the cylinder shock assembly is increased, the second piston and the second end of the damper move towards the first end cap compressing air within a first air pressure chamber. When the load is increased the primary coil spring is compressed and the volume of air within the first air pressure chamber decreases resulting in an increased air pressure.

Methodology Applied
Scientific EffectGas compression: Compression

Implementation Method 2

A primary coil spring is positioned within the air cylinder float and about the rod and positioned between the second piston and the first end cap. When the load is increased the primary coil spring is compressed

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Data Source

PatentEP2882602B1Cylinder shock assembly
Publication Date: 2018.05.09 HENDRICKSON USA LLC
  • EP2882602B1 patent drawingFigure 1
  • EP2882602B1 patent drawingFigure 2
  • EP2882602B1 patent drawingFigure 3

AI summary

A cylinder shock assembly comprising a damper with a first end, and a second end that extends into an air cylinder float. The damper has a rod positioned in the air cylinder float with one end positioned within a cavity of the damper and another end affixed to an end cap attached to the air cylinder float. A primary coil spring is positioned within the air cylinder float, wherein when a load applied to the cylinder shock assembly is increased, an end of the damper move towards the end cap compressing air within the air cylinder float, wherein as the load is increased the primary coil spring is compressed and the volume of air within the air cylinder decreases resulting in an increased air pressure, and wherein the air cylinder float is a solid member that does not expand as the air pressure within increases during compression.