Wax Bypass Valve Boot Segmentation for Axial Valve Motion

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Solution Overview

Problem

Existing thermally responsive wax plug valves in fluid flow applications face inefficiencies due to wax migration and uneven distribution within the chamber, leading to non-axial movement and potential leakage, which can reduce operational efficiency and cause the rubber boot to tear.

Innovation Solution

Incorporating wax separator members into the rubber boot to circumferentially separate the wax, preventing uneven distribution and enhancing the boot's structural integrity by acting as strengthening ribs.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If a rubber boot is used to seal the wax within the chamber, then the wax is contained and the valve operates thermally responsive, but the wax migrates and distributes unevenly within the chamber, causing non-axial movement and potential leakage

Engineering Contradiction:
Improvevalve operation reliabilityVSAvoidwax distribution uniformity
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The boot is divided into multiple segments or lobes that radially extend into the chamber, creating separate compartments that constrain wax movement. This segmentation prevents the wax from migrating freely and ensures more uniform distribution throughout the chamber, resolving the contradiction between containing the wax and maintaining uniform distribution.

Inventive Principle:
Principle #1Segmentation

2Ease of operation

If the wax is allowed to move freely within the chamber, then the thermal expansion can drive the valve, but the uneven distribution causes non-axial movement and can tear the rubber boot

Engineering Contradiction:
Improvevalve actuationVSAvoidboot structural integrity
Core Design Contradiction:
Ease of operationVSStrength

Solution Approach 1:

The boot incorporates localized reinforcing ribs or stiffening elements in specific areas to prevent tearing while maintaining flexibility elsewhere. These localized strength enhancements prevent boot failure due to uneven wax distribution and non-axial movement, while still allowing the valve to actuate properly in response to thermal expansion.

Inventive Principle:
Principle #3Local quality

3Productivity

If the valve bypasses fluid below predetermined temperature, then energy efficiency is improved, but the wax element may not maintain proper position due to uneven distribution

Engineering Contradiction:
Improvesystem efficiencyVSAvoidvalve positioning accuracy
Core Design Contradiction:
ProductivityVSManufacturing precision

Solution Approach 1:

The segmented boot structure preliminarily positions the wax in specific compartments before thermal expansion occurs. This preliminary arrangement ensures that when the wax expands due to heating, it does so in a controlled manner that maintains proper valve positioning accuracy, enabling precise temperature-based bypass control for optimal system efficiency.

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

The wax separator members ensure uniform wax distribution, maintaining axial movement and reducing the likelihood of boot tears, thereby enhancing the operational efficiency and reliability of the bypass valve.

Implementation Method 1

a wax element that expands when heated. When the wax is heated, it drives a valve against the seat

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3663734B1Thermal wax bypass valve utilizing boot with wax separators
Publication Date: 2021.09.29 HAMILTON SUNDSTRAND CORP
  • EP3663734B1 patent drawingFigure 1
  • EP3663734B1 patent drawingFigure 2
  • EP3663734B1 patent drawingFigure 3A~3B

AI summary

A bypass system has a source of a fluid to be cooled and a heat exchanger for selectively cooling fluid. A piston (40) is moveable along an axis allowing movement of a valve poppet (22) toward and away from the valve seat (24). The piston contacts a boot (38). A wax element (36) is disposed in a chamber (49), such that the wax element expands as a temperature of the fluid to be cooled increases, and causes the valve poppet to move against the valve seat. The boot has wax separator structures (140). A bypass valve is also disclosed.