Bimetallic Thermal Bypass Valve for Debris-Resistant Fluid Diversion

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Solution Overview

Problem

Current thermal bypass systems using wax actuators are prone to failure due to debris accumulation, short life expectancy, and potential damage to other components, as they can get stuck, leading to catastrophic failures and inefficient fluid diversion.

Innovation Solution

A thermal bypass valve utilizing a bimetallic disc that pivots within a wedge-shaped chamber, switching fluid flow between a component and a cooler based on temperature, with integrated pressure relief and check valves to prevent damage and ensure continuous operation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If sliding spool type valves are used to divert fluid based on temperature, then fluid diversion is achieved, but the valve gets stuck due to debris accumulation between tubes

Engineering Contradiction:

Improvevalve operation reliabilityVSAvoiddebris accumulation

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention extracts the moving spool component from the valve design and replaces it with a stationary spool and a movable piston. This removes the sliding interface that accumulates debris, eliminating the sticking problem while maintaining the fluid diversion function through piston position changes instead.

Inventive Principle:

Principle #2Taking out (Extraction)

Solution Approach 2:

The invention introduces a piston as an intermediary element between the wax actuator and the spool. The piston translates the linear expansion of the wax into rotational movement of a cam or lever that shifts the spool, avoiding direct sliding contact between tubes and reducing debris accumulation issues.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Reliability

If sliding spool type valves are used, then fluid diversion is achieved, but the wax actuator explodes and destroys components when tubes get stuck

Engineering Contradiction:

Improvesystem safetyVSAvoidwax actuator explosion

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention incorporates a relief valve or pressure relief mechanism that activates before the wax actuator can build up excessive pressure. This cushioning mechanism prevents the catastrophic failure mode of wax explosion by providing a safe pressure release path, protecting surrounding components from damage.

Inventive Principle:

Principle #11Beforehand cushioning (Prior cushioning)

Solution Approach 2:

The invention replaces the direct mechanical coupling between the wax actuator and the spool with an indirect mechanism involving a piston and cam/lever system. This substitution allows for controlled movement and includes built-in pressure relief features that prevent the wax actuator from exploding when obstruction occurs.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Reliability

If sliding spool type valves are used, then fluid diversion is achieved, but the valve fails in bypass mode preventing fluid flow to cooler

Engineering Contradiction:

Improvebypass mode reliabilityVSAvoidfluid flow control

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The invention designs the piston-spool mechanism so that the system automatically and reliably shifts between bypass mode and cooling mode based on temperature-induced wax expansion. The self-service mechanism ensures consistent operation without manual intervention, preventing failure in bypass mode through proper mechanical alignment and pressure-balanced design.

Inventive Principle:

Principle #25Self-service

4Duration of action of moving object

If wax actuators are used to drive sliding spool valves, then thermal response is achieved, but the system has short life expectancy of only 30,000 cycles

Engineering Contradiction:

Improveactuator life expectancyVSAvoidsystem longevity

Core Design Contradiction:

Duration of action of moving objectVSReliability

Solution Approach 1:

The invention extracts the high-wear sliding spool from the system and replaces it with a piston-based mechanism that has minimal sliding contact. This significantly reduces mechanical wear and extends the operational life of the actuator from 30,000 cycles to potentially unlimited service life, improving overall system reliability.

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 bimetallic disc design enhances the life expectancy of the system to at least 100,000 cycles, prevents damage to other components, and ensures efficient fluid diversion by avoiding sticking issues and maintaining fluid flow even in failure modes.

Implementation Method 1

a bimetallic disc pivotably arranged in the chamber... when the fluid reaches a predetermined temperature

Methodology Applied

Scientific EffectBimetallic effect: Bi-Metallic Strip

Implementation Method 2

the pressure relief valve comprises a spring and a ball

Methodology Applied

Scientific EffectSpring force: Spring

Data Source

PatentUS11474545B2Thermal bypass valve

Publication Date: 2022.10.18 FREMONT & MURPHY LLC

AI summary

A thermal bypass valve for diverting fluid, including an inlet, a chamber in fluid communication with the inlet, a bimetallic disc pivotably arranged in the chamber, a first outlet in fluid communication with the chamber, and a second outlet in fluid communication with the chamber, wherein the bimetallic disc is operatively arranged to, in a first state, divert fluid to the first outlet, and in a second state, when the fluid reaches a predetermined temperature, divert the fluid to the second outlet.