Capacity Control Valve Tapered Guide Ejects Particles

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Solution Overview

Problem

Fine particles in the operating fluid of flow control valves, such as ferrous, aluminum, and silicon particles, cause friction and malfunction by getting stuck between the valve rod and the valve housing, leading to delayed response and wear of sliding surfaces.

Innovation Solution

A flow control valve design featuring a tapered surface within the through bore that expands away from the valve chamber, allowing pressure fluid to sweep away fine particles and prevent them from accumulating between the valve rod and the housing, reducing friction and wear.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Object-affected harmful factors

If a filter is disposed before the fluid is introduced into the flow control valve to collect particles, then the particles are removed from the fluid, but the filter loads rapidly and deteriorates the performance of the flow control valve

Engineering Contradiction:
Improvefine particles in fluidVSAvoidfilter loading
Core Design Contradiction:
Object-affected harmful factorsVSDevice complexity

Solution Approach 1:

The harmful fine particles are extracted from the fluid stream by the tapered surface structure. The particles that enter the space between the tapered surface and valve rod are automatically ejected back into the fluid stream, preventing them from accumulating and causing malfunction. This extraction mechanism eliminates the need for external filters.

Inventive Principle:
Principle #2Taking out (Extraction)

Solution Approach 2:

The tapered surface structure converts the potentially harmful effect of fine particles into a beneficial self-cleaning mechanism. The particles that would normally cause friction and malfunction are instead used to demonstrate the effectiveness of the tapered design - they enter the gap and are automatically ejected, proving the system's ability to prevent accumulation without filters.

Inventive Principle:
Principle #22Blessing in disguise (Convert harm into benefit)

2Object-affected harmful factors

If the filter is used to remove particles, then particle accumulation is prevented, but the pressure of the control fluid increases making control difficult

Engineering Contradiction:
Improvefine particles in fluidVSAvoidcontrol fluid pressure
Core Design Contradiction:
Object-affected harmful factorsVSStress or pressure

Solution Approach 1:

The tapered surface structure extracts particles from the fluid path locally, allowing continuous particle removal without restricting overall fluid flow. This prevents pressure buildup while maintaining particle separation, as the extraction occurs through the tapered gap rather than through a filter element that would restrict flow.

Inventive Principle:
Principle #2Taking out (Extraction)

3Reliability

If fine particles are present in the operating fluid, then the valve rod operation is deteriorated, but removing particles requires complex filtration systems

Engineering Contradiction:
Improvevalve rod operationVSAvoidparticle removal system
Core Design Contradiction:
ReliabilityVSDevice complexity

Solution Approach 1:

The tapered surface structure creates a self-service particle removal system. The geometry of the tapered surface automatically ejects particles that enter the gap between the surface and valve rod, creating a self-cleaning mechanism that maintains reliable valve rod operation without requiring external filtration systems or additional components.

Inventive Principle:
Principle #25Self-service

4Ease of operation

If a through bore with cylindrical surface is used, then the valve rod is guided, but fine particles accumulate between the surface and valve rod causing friction

Engineering Contradiction:
Improvevalve rod guidanceVSAvoidfine particles accumulation
Core Design Contradiction:
Ease of operationVSObject-affected harmful factors

Solution Approach 1:

The cylindrical guide surface is replaced with a tapered surface that has a varying diameter along its length. This curvature change creates an expanding gap between the tapered surface and the valve rod, preventing particle accumulation while still providing adequate guidance. The tapered geometry allows particles to be ejected back into the fluid stream rather than trapped against a parallel cylindrical surface.

Inventive Principle:
Principle #14Spheroidality (Curvature)

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

Prevents malfunction and wear of the valve rod by effectively ejecting fine particles, ensuring smooth operation and reduced slide friction, even in the presence of fine particles in the fluid.

Implementation Method 1

pressure fluid to sweep away fine particles

Methodology Applied
Scientific EffectFluid flow:

Data Source

PatentEP1895161B1Capacity control valve
Publication Date: 2018.05.02 EAGLE INDS
  • EP1895161B1 patent drawingFigure 1
  • EP1895161B1 patent drawingFigure 2
  • EP1895161B1 patent drawingFigure 3

AI summary

A capacity control valve where a valve section is caused to be in contact with and separated from a valve seat by a valve rod to control the flow rate of pressurized fluid. The capacity control valve includes a first valve rod having a valve section and having a first peripheral surface formed on its outer periphery, a first valve chamber having a valve seat that comes into contact with and is separated from the valve section and having a first path into which pressurized fluid flows, and a valve housing having a through-hole that is movably fitted on the first peripheral surface of the first valve rod. The through-hole of the valve housing has a first tapered surface diverging as it goes away in the axial direction from the first valve chamber.