Gasket Radial Thickness Control for High-Temperature Sealing Stability

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Solution Overview

Problem

Conventional sealing structures in hybrid and electric vehicles face instability due to thermal expansion differences between rubber gaskets and aluminum components, leading to meandering and tilting issues at high temperatures, compromising sealing performance.

Innovation Solution

A gasket with a vertically long cross-sectional shape is designed to maintain a perimeter not greater than the mounting groove's radially outer side wall surface at high temperatures, ensuring stable contact and preventing meandering and tilting, with the perimeter of the outer circumferential surface being between 98% and 99% of the mounting groove's perimeter at 100°C.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the gasket is mounted to fit along the radially outer side wall surface of the mounting groove to prevent tilting, then the gasket is prevented from tilting inside the mounting groove under internal pressure, but the gasket expands more than the mounting groove at high temperatures causing meandering and unstable sealing performance

Engineering Contradiction:
Improvesealing performance stabilityVSAvoidgasket position stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The invention changes the dimensional parameters of the gasket by controlling its radial thickness to be 3mm or less, which fundamentally alters how the gasket responds to thermal expansion. This parameter change ensures that even at high temperatures, the gasket's outer circumferential surface perimeter remains less than or equal to the mounting groove's radially outer side wall surface perimeter, preventing meandering while maintaining anti-tilting functionality

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention performs preliminary action by pre-controlling the gasket's radial thickness during manufacturing to 3mm or less. This preliminary dimensional control ensures that under subsequent thermal expansion during operation, the gasket will not exceed the mounting groove boundaries, thereby preventing meandering before it occurs

Inventive Principle:
Principle #10Preliminary action

2Reliability

If the gasket has a vertically long cross-sectional shape to maintain sealing performance with large dimensional error, then the gasket can exhibit stable sealing performance, but the gasket easily tilts inside the mounting groove under internal pressure

Engineering Contradiction:
Improvesealing performanceVSAvoidanti-tilting capability
Core Design Contradiction:
ReliabilityVSEase of operation

Solution Approach 1:

The invention changes the radial thickness parameter to 3mm or less, which modifies the gasket's mechanical behavior under internal pressure. This parameter change reduces the gasket's tendency to tilt while maintaining sealing effectiveness through the controlled dimensional relationship with the mounting groove

Inventive Principle:
Principle #35Parameter changes

3Reliability

If the gasket radial thickness is increased to improve sealing with large dimensional error, then sealing performance is improved, but thermal expansion difference causes meandering at high temperatures

Engineering Contradiction:
Improvesealing performanceVSAvoidthermal expansion control
Core Design Contradiction:
ReliabilityVSTemperature

Solution Approach 1:

The invention changes the radial thickness parameter to 3mm or less, which directly controls the gasket's thermal expansion characteristics. This parameter change ensures that at high temperatures up to 100°C, the gasket's outer circumferential surface perimeter remains less than or equal to the mounting groove's radially outer side wall surface perimeter, preventing meandering

Inventive Principle:
Principle #35Parameter changes

Solution Approach 2:

The invention explicitly addresses thermal expansion by designing the gasket with radial thickness of 3mm or less, accounting for the differential thermal expansion between the rubber gasket and aluminum mounting groove. This design ensures that even when both components expand at high temperatures, the gasket does not exceed the groove boundaries

Inventive Principle:
Principle #37Thermal expansion

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

This design ensures stable sealing performance even at high temperatures by preventing meandering and tilting, maintaining effective sealing across varying thermal conditions.

Implementation Method 1

Since the gasket 500 and the one member 200 are made of different materials (e.g., the former being made of rubber and the latter being made of aluminum), they undergo expansion at different amounts because of the difference in linear expansion coefficient.

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Data Source

PatentEP3141781B1Gasket and sealing structure
Publication Date: 2020.05.06 NOK CORP
  • EP3141781B1 patent drawingFigure 1~3
  • EP3141781B1 patent drawingFigure 4~6
  • EP3141781B1 patent drawingFigure 7~8

AI summary

The present invention provides a gasket and a sealing structure capable of exhibiting stable sealing performance even when used in a high-temperature environment. A gasket 100 is mounted in an annular mounting groove 210 provided to a first member 200 and makes tight contact with a groove bottom surface 211 of this mounting groove 210 and an end face 310 of a second member 300, to seal a gap between the first member 200 and the second member 300. A perimeter of an outer circumferential surface 130 of the gasket 100 is designed to be not greater than a perimeter of a radially outer side wall surface 212 of the mounting groove 210 in a condition with a highest temperature in an environment of use.