End Cap Retention Device With Mechanical Interlock

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Solution Overview

Problem

Filter assemblies in high-pressure hydraulic systems face challenges in securely retaining filtration media due to sensitivity to contamination and potential separation of end caps from the filter element, especially under internal pressure, which can lead to reduced performance and component failure.

Innovation Solution

The use of end caps with mechanically locked retainers that define regions for bonding agents to form a mechanical interlock, ensuring secure retention of the filter media even if adhesion is incomplete, thereby preventing end cap separation and maintaining the effective surface area of the filter.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If adhesive bonding alone is used to secure filter media in end caps, then manufacturing simplicity is maintained, but retention reliability deteriorates under high pressure causing end cap separation

Engineering Contradiction:

Improveretention reliabilityVSAvoidstructural complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent combines adhesive bonding with mechanical interlocking features (undercuts, recesses, protrusions) to create a hybrid retention system. The bonding agent is applied in specific patterns within these mechanical features, merging chemical adhesion with mechanical resistance to separation forces under high pressure.

Inventive Principle:

Principle #5Merging (Combining)

Solution Approach 2:

The end cap structure is segmented into multiple retention zones with different geometries (undercuts, recesses, protrusions) that work together. Each segment provides a specific function in the mechanical interlocking system, distributing the retention load across multiple locations rather than relying on a single bonding interface.

Inventive Principle:

Principle #1Segmentation

2Weight of moving object

If end cap thickness is reduced for design flexibility, then manufacturing cost and weight decrease, but structural strength deteriorates making separation more likely

Engineering Contradiction:

Improveend cap weightVSAvoidstructural strength

Core Design Contradiction:

Weight of moving objectVSStrength

Solution Approach 1:

The patent employs thin-walled end cap designs with integrated mechanical interlocking features and optimized bonding agent placement. The thin walls are compensated by the mechanical features (undercuts, recesses) that provide structural reinforcement at critical locations without increasing overall wall thickness.

Inventive Principle:

Principle #30Flexible shells and thin films

Solution Approach 2:

The retention system uses composite construction combining the end cap material, bonding agent, and mechanical interlocking features. This composite approach allows thin end caps to achieve equivalent or superior retention strength by leveraging the synergistic effects of multiple retention mechanisms.

Inventive Principle:

Principle #40Composite materials

3Manufacturing precision

If conventional bonding agent application is used, then manufacturing simplicity is maintained, but bonding effectiveness deteriorates leading to incomplete adhesion

Engineering Contradiction:

Improvebonding effectivenessVSAvoidmanufacturing complexity

Core Design Contradiction:

Manufacturing precisionVSEase of manufacture

Solution Approach 1:

The end cap geometry is pre-designed with integrated undercuts, recesses, and protrusions that guide bonding agent placement. These pre-formed features ensure the bonding agent is automatically positioned in optimal locations during assembly, eliminating the need for complex external application processes while ensuring consistent bonding effectiveness.

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 solution enhances the retention of filter media within the end caps, reducing the risk of separation and maintaining filter efficiency, even under high pressure, without the need for costly machining and allowing for thinner end cap designs with larger locking surfaces.

Implementation Method 1

at least one retainer (50) mechanically locked to the end cap (30) in the cavity and defining a region into which the bonding agent can flow to form a mechanical interlock with the retainer

Methodology Applied

Scientific EffectMechanical interlock: Mechanical Fastener

Data Source

PatentEP2809424B1End cap retention device

Publication Date: 2020.01.08 PARKER HANNIFIN CORP

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AI summary

Provided is a filter assembly including at least one end cap and at least one retainer mechanically locked to the end cap in a cavity and defining a region into which the bonding agent can flow to form a mechanical interlock with the retainer. Even if the bonding agent does not fully adhere to the end cap, the filter media will be secured in the end cap via the mechanical interlock of the bonding agent and retainer, thereby preventing end cap separation from the element.