Flexible Bladder Accumulator Support for Stress Control

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Solution Overview

Problem

Hydraulic accumulators with compressible gas bladders face issues of excessive expansion, leading to high stress areas, which existing designs fail to adequately address, potentially causing mechanical stress and inefficiency in energy storage.

Innovation Solution

A hydraulic accumulator design featuring a flexible bladder with a support mechanism that limits or prevents excessive expansion by engaging the bladder when it is in an expanded condition, allowing it to expand naturally and switch to a partially collapsed state as pressure increases, thereby managing stress and optimizing energy storage.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Use of energy by moving object

If the flexible bladder is allowed to expand freely to store more energy, then the energy storage capacity increases, but excessive expansion creates high stress areas that may cause mechanical failure

Engineering Contradiction:

Improveenergy storage capacityVSAvoidbladder structural integrity

Core Design Contradiction:

Use of energy by moving objectVSStrength

Solution Approach 1:

A support structure acts as an intermediary element between the flexible bladder and the housing. This support engages with the bladder at specific locations to provide mechanical assistance, preventing excessive expansion and high stress concentration while allowing sufficient expansion for energy storage. The support serves as a mediator that enables the bladder to operate within safe stress limits.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The bladder is designed as a flexible shell that can expand and contract to store and release hydraulic energy. The flexible nature of the bladder allows it to deform under pressure differential, enabling energy storage when pressure is high and energy release when pressure is low, while the support structure ensures this deformation remains within safe limits.

Inventive Principle:

Principle #30Flexible shells and thin films

2Strength

If the bladder material is made more robust to withstand high stress, then the strength increases, but the flexibility and natural expansion capability are reduced

Engineering Contradiction:

Improvebladder stress resistanceVSAvoidbladder expansion flexibility

Core Design Contradiction:

StrengthVSAdaptability or versatility

Solution Approach 1:

The support structure is divided into multiple engagement locations distributed around the bladder. This segmentation allows different portions of the bladder to expand to different degrees, with the support providing localized assistance where needed. The segmented approach maintains overall bladder flexibility while preventing excessive expansion at critical stress points.

Inventive Principle:

Principle #1Segmentation

3Strength

If a rigid support structure is used to prevent excessive expansion, then the stress control improves, but the device complexity and manufacturing difficulty increase

Engineering Contradiction:

Improvestress control capabilityVSAvoidsupport structure manufacturing

Core Design Contradiction:

StrengthVSEase of manufacture

Solution Approach 1:

The support structure is merged with the housing as an integrated component rather than a separate attachment. This combining of functions reduces the number of parts, simplifies assembly, and reduces manufacturing complexity while still providing the necessary stress control functionality through strategically positioned engagement features.

Inventive Principle:

Principle #5Merging (Combining)

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 effectively prevents high stress areas and optimizes energy storage by allowing the bladder to expand naturally while limiting further expansion, ensuring efficient operation and reducing mechanical stress.

Implementation Method 1

A compressible gas acts as an energy storage mechanism on the incompressible liquid

Methodology Applied

Scientific EffectCompression: Compression

Implementation Method 2

The flexible bladder is allowed to expand according to its natural shape to prevent the creation of high areas of stress

Methodology Applied

Scientific EffectElasticity: Elasticity

Implementation Method 3

A liquid is positioned in the chamber and is in contact with the flexible bladder. The volume of liquid within the chamber increases as a pressure of the liquid increases to compress the gas

Methodology Applied

Scientific EffectHydraulic pressure: Pressure Increase

Data Source

PatentUS11359648B2Accumulator with flexible inflatable container

Publication Date: 2022.06.14 TENNECO AUTOMOTIVE OPERATING COMPANY INC

AI summary

An accumulator includes a housing, a flexible bladder and a support. The housing includes a chamber having a defined volume and a passage extending through the housing. The flexible bladder is positioned within the chamber and contains a compressible gas. The bladder being operable in an expanded condition and a partially collapsed condition. The support is positioned in the chamber and engages the flexible bladder when the flexible bladder is in the expanded condition. Liquid is positioned in the chamber and in contact with the flexible bladder. A volume of the liquid within the chamber is at a minimum when the flexible bladder is in the expanded condition. The volume of liquid within the chamber increases as a pressure of the liquid increases to compress the gas and operate the flexible bladder in the partially collapsed condition.