Engine Breathing Valve Bushing Seal Thermal Expansion

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Solution Overview

Problem

Existing engine breathing system valves experience fluid-flow leakage and movement obstruction due to high operating temperatures and thermal expansion, which conventional seals like elastomeric materials fail to address effectively.

Innovation Solution

The use of a bushing and dual seal members, comprising metal annular washers with specific clearances and axial seals, to form metal-to-metal seals around the stem, preventing fluid-flow leakage while accommodating thermal expansion and facilitating stem movement.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional elastomeric seals are used in engine breathing system valves, then the valve structure is simple, but fluid-flow leakage occurs and seal failure happens due to high operating temperatures and thermal expansion

Engineering Contradiction:

Improveseal reliabilityVSAvoidseal structure complexity

Core Design Contradiction:

ReliabilityVSDevice complexity

Solution Approach 1:

The patent employs a composite sealing system combining metal annular washers with specific clearance gaps and axial seals. This composite structure replaces conventional single-material elastomeric seals, providing temperature resistance and dimensional stability while maintaining sealing effectiveness through the combination of metal components and controlled clearances.

Inventive Principle:

Principle #40Composite materials

Solution Approach 2:

The invention changes the sealing mechanism from elastic deformation (conventional elastomeric seals) to metal-to-metal contact with controlled clearance gaps. The axial seals provide contact pressure while the radial clearance gaps accommodate thermal expansion, fundamentally changing how sealing is achieved under high temperature conditions.

Inventive Principle:

Principle #35Parameter changes

2Reliability

If tight seals are used to prevent fluid-flow leakage, then sealing effectiveness improves, but stem movement becomes obstructed due to thermal expansion

Engineering Contradiction:

Improvesealing effectivenessVSAvoidstem movement

Core Design Contradiction:

ReliabilityVSEase of operation

Solution Approach 1:

The sealing system is segmented into multiple independent components: axial seals for preventing leakage and radial clearance gaps for accommodating movement. This segmentation allows each component to perform its specific function without interfering with the other, enabling both effective sealing and free stem movement during thermal expansion.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

The radial clearance gaps act as intermediaries between the stem and the valve body, allowing thermal expansion to occur without creating binding forces that would obstruct movement. The axial seals serve as intermediaries for sealing, providing contact pressure to prevent leakage while the clearance gaps handle the dimensional changes.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If metal-to-metal seals with clearance gaps are used, then thermal expansion is accommodated and stem movement is facilitated, but manufacturing precision requirements increase

Engineering Contradiction:

Improvethermal expansion accommodationVSAvoidclearance gap precision

Core Design Contradiction:

Adaptability or versatilityVSManufacturing precision

Solution Approach 1:

The patent applies different quality requirements to different parts of the sealing system. The axial seals require precise fit and contact pressure, while the radial clearance gaps are designed with larger tolerances to accommodate manufacturing variations. This local differentiation of precision requirements reduces overall manufacturing difficulty while maintaining sealing effectiveness.

Inventive Principle:

Principle #3Local quality

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 minimizes fluid-flow leakage and supports stem movement across a wide temperature range, ensuring reliable operation and reduced risk of seal failure due to thermal expansion.

Implementation Method 1

forming a first radial seal around an outer diametrical surface of the stem and at a side of the bushing; forming a second radial seal around the outer diametrical surface of the stem and at a side of the bushing; and forming an axial seal on an axial surface of the bushing and at a side of the bushing

Methodology Applied

Scientific EffectMetal-to-metal seal:

Implementation Method 2

supports stem movement across a wide temperature range, ensuring reliable operation and reduced risk of seal failure due to thermal expansion

Methodology Applied

Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP2625402B1Engine breathing system valve and seal

Publication Date: 2019.12.11 BORGWARNER INC

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AI summary

One embodiment may include a bushing (100, 300) and a seal member (102, 104, 200, 302). The bushing may be located in a cavity (56) of a stationary body (46) of an engine breathing system valve (12). The bushing may be located around a moveable stem (48) of the engine breathing system valve in order to facilitate movement of the valve. The seal member may be located in the cavity and around the stem. The seal member may substantially prevent fluid-flow between an outer diametrical surface (76) of the stem and a confronting inner diametrical surface (120, 128, 202, 308) of the seal member.