Dual-Bladder Accumulator Sealing With Radial Annular Protrusions

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Solution Overview

Problem

Conventional bladder-type accumulators face issues with gas leakage due to insufficient contact between gas shielding and liquid resistant materials at the peripheral edge, leading to degraded sealing performance.

Innovation Solution

The accumulator design features a bladder with an outer-diameter-side bladder made of liquid-resistant material and an inner-diameter-side bladder made of low gas permeability material, both with annular protrusions that compress radially to enhance sealing, ensuring a tight fit and preventing gas leakage between the bladders.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a bladder is made of two materials (gas shielding material and liquid resistant material) to improve sealing performance, then gas shielding properties and liquid resistance are improved, but the materials do not come into sufficient close contact at the peripheral edge, causing gas leakage

Engineering Contradiction:
Improvesealing performanceVSAvoidcontact precision at joint
Core Design Contradiction:
ReliabilityVSManufacturing precision

Solution Approach 1:

The bladder is segmented into two separate materials (gas shielding material and liquid resistant material) that are joined together. Each material is optimized for its specific function, and the segmentation allows independent optimization of each material's properties while maintaining overall sealing performance.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The peripheral edge of the bladder is given a three-dimensional structure with an annular protrusion that extends in the radial direction. This dimensional change from a flat edge to a protruding structure enables the protrusion to be compressed and deformable, ensuring sufficient contact pressure and close contact at the joint between the two materials.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

2Reliability

If the peripheral edge of the bladder is compressed to improve sealing, then contact pressure increases, but without proper structural features, the tightening margin is insufficient

Engineering Contradiction:
Improvesealing performanceVSAvoidtightening margin
Core Design Contradiction:
ReliabilityVSForce

Solution Approach 1:

The bladder is pre-formed with an annular protrusion at its peripheral edge before installation. This preliminary structural feature ensures that when the bladder is installed and compressed, the protrusion provides immediate contact pressure and tightening action, creating sufficient sealing force without requiring additional compression mechanisms.

Inventive Principle:
Principle #10Preliminary action

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 significantly improves sealing performance by ensuring a great tightening margin and preventing gas from entering the liquid chamber, maintaining the integrity of both gas and liquid compartments.

Implementation Method 1

The peripheral edge portion of the outer-diameter-side bladder includes, on an outer diameter side thereof, an outer annular protrusion, and the peripheral edge portion of the inner-diameter-side bladder includes, on the inner diameter side thereof, an inner annular protrusion configured to contact the holder. The inner annular protrusion of the peripheral edge portion of the inner-diameter-side bladder and the outer annular protrusion of the peripheral edge portion of the outer-diameter-side bladder can be compressed in a radial direction by compression force of the holder in the radial direction

Methodology Applied
Scientific EffectCompression: Compression

Data Source

PatentEP3418583B1accumulator
Publication Date: 2021.08.04 EAGLE INDS
  • EP3418583B1 patent drawingFigure 1
  • EP3418583B1 patent drawingFigure 2(a)~2(b)
  • EP3418583B1 patent drawingFigure 3

AI summary

Provided is an accumulator having excellent sealing performance at a joint between bladders. An accumulator 10 is configured such that a bladder 30 is disposed on the inside of a shell 20 to divide an internal space of the shell 20 into a gas chamber G and a liquid chamber R. The bladder 30 includes an outer-diameter-side bladder 31 having a peripheral edge portion 31a disposed on an inner peripheral portion 20b of the shell 20, and an inner-diameter-side bladder 32 disposed on the inside of the outer-diameter-side bladder 31 and having a peripheral edge portion 32a formed to protrude toward an inner diameter side. The accumulator 10 includes a holder 40 configured to face the inner peripheral portion 20b of the shell 20 to hold, from the inner diameter side, the peripheral edge portion 31a of the outer-diameter-side bladder 31 and the peripheral edge portion 32a of the inner-diameter-side bladder 32. The peripheral edge portion 31a of the outer-diameter-side bladder 31 includes, on an outer diameter side thereof, an outer annular protrusion 31g, and the peripheral edge portion 32a of the inner-diameter-side bladder 32 includes, on the inner diameter side thereof, an inner annular protrusion 32h configured to contact the holder 40.