Accumulator Bladder Sealing Rigid Body Mediator

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Solution Overview

Problem

Conventional bladder-type accumulators face limitations in achieving high sealing performance due to the reliance on compressive deformation of raised portions for sealing, which restricts further improvements in sealing efficiency between the shell and bladder.

Innovation Solution

Incorporating a rigid body with higher stiffness than the bladder materials, disposed between the peripheral edge portions of the outer-diameter-side and inner-diameter-side bladders, to enhance the tightening margin and prevent fluid leakage, along with annular raised portions for increased compression force and localized sealing performance.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If compressive deformation of raised portion is used for sealing, then sealing performance is improved, but further improvements in sealing efficiency are limited

Engineering Contradiction:
Improvesealing performanceVSAvoidsealing structure complexity
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

A rigid body is introduced as an intermediary component between the holder and the bladder peripheral edge portions. This rigid body mediates the force transmission from the holder to the bladders, providing a more effective sealing mechanism through direct mechanical contact and force distribution, thereby overcoming the limitations of relying solely on compressive deformation of the raised portions.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The sealing structure is segmented into multiple functional components: the holder, the rigid body, and the peripheral edge portions of the bladders. This segmentation allows each component to perform its specific function optimally - the holder provides holding force, the rigid body distributes and transmits this force, and the bladder edges provide the sealing interface, thereby improving overall sealing performance while managing structural complexity.

Inventive Principle:
Principle #1Segmentation

2Ease of manufacture

If single species of rubber material is used for bladder, then manufacturing is simplified, but both liquid resistance and gas permeability cannot be sufficiently fulfilled

Engineering Contradiction:
Improvebladder manufacturing simplicityVSAvoidliquid resistance and gas permeability
Core Design Contradiction:
Ease of manufactureVSReliability

Solution Approach 1:

The bladder is constructed using composite materials - specifically, a liquid-resistant rubber material on the liquid chamber side and a rubber material with favorable gas shielding properties on the gas chamber side. This composite structure allows each layer to optimize its specific function, achieving both excellent liquid resistance and gas permeability control that would be impossible with a single material species.

Inventive Principle:
Principle #40Composite materials

3Ease of operation

If holder attaches to peripheral edge portions, then bladders are held in position, but sealing performance between shell and bladder is insufficient

Engineering Contradiction:
Improvebladder positioningVSAvoidsealing performance between shell and bladder
Core Design Contradiction:
Ease of operationVSReliability

Solution Approach 1:

The rigid body serves as a mediator between the holder and the bladder peripheral edges. It receives the holding force from the holder and transmits it to the bladders in a manner that enhances sealing contact with the shell, thereby improving the sealing performance between the shell and bladder while maintaining easy positioning through the holder attachment.

Inventive Principle:
Principle #24Intermediary (Mediator)

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 ensures excellent sealing performance by evenly compressing the bladder edges and providing a deformation margin, preventing fluid flow between the bladders and enhancing the assembly process, thus achieving high sealing efficiency.

Implementation Method 1

The peripheral edge portion of the inner-diameter-side bladder and the peripheral edge portion of the outer-diameter-side bladder can ensure a tightening margin between each bladder and the rigid body

Methodology Applied
Scientific EffectElastic deformation: Elasticity

Implementation Method 2

a holder configured to face the inner peripheral face of the shell to hold, from the inner diameter side, the peripheral edge portion of the outer-diameter-side bladder and the peripheral edge portion of the inner-diameter-side bladder

Methodology Applied
Scientific EffectMechanical constraint: Mechanical Force

Data Source

PatentEP3418584B1accumulator
Publication Date: 2020.12.23 EAGLE INDS
  • EP3418584B1 patent drawingFigure 1
  • EP3418584B1 patent drawingFigure 2
  • EP3418584B1 patent drawingFigure 3

AI summary

Provided is an accumulator having excellent sealing performance between a shell and a bladder. An accumulator 1 is configured such that a peripheral edge portion of a bladder 3 formed of an elastic member is in close contact with the inside of a shell 2 to divide an internal space of the shell 2 into a gas chamber G and a liquid chamber R. The bladder 3 includes an outer-diameter-side bladder 4 having a peripheral edge portion 6 disposed on an inner peripheral face 2a of the shell 2, and an inner-diameter-side bladder 5 having a peripheral edge portion 7 disposed on an inner diameter side of the outer-diameter-side bladder 4. The accumulator includes a ring-shaped holder 8 configured to face the inner peripheral face 2a of the shell 2 to hold, from the inner diameter side, the peripheral edge portion 6 of the outer-diameter-side bladder 4 and the peripheral edge portion 7 of the inner-diameter-side bladder 5, and a rigid body 9 disposed between the peripheral edge portion 6 of the outer-diameter-side bladder 4 and the peripheral edge portion 7 of the inner-diameter-side bladder 5 and having a higher stiffness than those of the peripheral edge portion 6 of the outer-diameter-side bladder 4 and the peripheral edge portion 7 of the inner-diameter-side bladder 5.