Servo Valve Nozzle Filtration for Clog-Resistant Maintenance

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Solution Overview

Problem

Servo valves are prone to blockages due to contaminants in the fluid, leading to inaccurate operation and frequent filter clogging, which requires frequent cleaning or replacement, despite the use of prior art contaminant filters.

Innovation Solution

A nozzle assembly with a tubular filter having a mesh with 0.1mm absolute filtration, integrated into the servo valve design, featuring a nozzle fitting adapter with slots for tool access, secure attachment methods, and a spring member for fluid communication, allowing for effective contaminant filtration and easy replacement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a particulate filter is provided between the fluid supply and fluid port to filter out contaminants, then the frequency and severity of blockages are reduced, but the filter itself becomes clogged after sustained use and requires removal and cleaning/replacement

Engineering Contradiction:
Improvefrequency of blockagesVSAvoidfilter maintenance
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The filter is segmented into a modular design where the filter element can be independently removed from the filter housing. The filter element is held by a retaining ring that can be independently accessed and removed, allowing the filter element to be replaced without removing the entire filter assembly from the servo valve.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter element is nested within the filter housing, with the retaining ring providing independent access to the filter element. This nested structure allows the filter element to be removed and replaced while the filter housing remains in place, facilitating easy maintenance without complete disassembly.

Inventive Principle:
Principle #7Nested doll (Nesting)

2Reliability

If the filter is integrated into the servo valve assembly, then filtration is effective, but the assembly becomes more complex and requires more steps for filter replacement

Engineering Contradiction:
Improvecontaminant filtrationVSAvoidassembly structure
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The filter assembly is segmented into distinct functional components: filter housing, filter element, and retaining ring. This segmentation allows each component to be optimized independently and facilitates easy replacement of only the filter element when needed.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter housing serves multiple functions: it houses the filter element, provides fluid passage, and integrates with the servo valve assembly. The retaining ring provides both retention and release functions through its interaction with the housing features.

Inventive Principle:
Principle #6Universality (Multi-functionality)

3Reliability

If the filter requires complete disassembly of the servo valve for cleaning or replacement, then thorough maintenance can be achieved, but time is lost and productivity is reduced

Engineering Contradiction:
Improvemaintenance thoroughnessVSAvoidtime for maintenance
Core Design Contradiction:
ReliabilityVSProductivity

Solution Approach 1:

The filter system is segmented to allow independent access to the filter element through the retaining ring mechanism. This enables maintenance personnel to service the filter element quickly without disassembling the entire servo valve, significantly reducing maintenance time while maintaining thoroughness.

Inventive Principle:
Principle #1Segmentation

Solution Approach 2:

The filter element is extracted as a separate, independently replaceable component from the filter housing. The retaining ring provides a simple mechanism to release and remove the filter element, allowing quick replacement without removing other components of the servo valve assembly.

Inventive Principle:
Principle #2Taking out (Extraction)

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 significantly reduces the frequency of blockages and maintenance by providing robust filtration and easy filter replacement, extending the operation time between maintenance cycles while maintaining precise control over actuator movement.

Implementation Method 1

the tubular filter comprises a mesh configured to provide an absolute filtration of around 0.1mm

Methodology Applied
Scientific EffectFiltration: Filter (physical)

Data Source

PatentEP3473865B1Nozzle assembly with filter for a servovalve
Publication Date: 2023.08.30 HAMILTON SUNDSTRAND CORP
  • EP3473865B1 patent drawingFigure 1
  • EP3473865B1 patent drawingFigure 2
  • EP3473865B1 patent drawingFigure 3a

AI summary

The present disclosure relates to a nozzle assembly (20) for a servo valve. The nozzle assembly (20) comprises a nozzle (26) including a nozzle inlet (26b) and a nozzle outlet (26a), and a tubular filter (40) mounted to the nozzle (26) for filtering fluid flowing into the nozzle (26) through the nozzle inlet (26b).