Elastic Sleeve Support for Combustion Engine Gas Tightness

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Solution Overview

Problem

The existing blind internal combustion engines face challenges in maintaining gas tightness due to thermal expansions between aluminum engine blocks and cast iron sleeves, leading to increased cold contact pressures and risks of plasticization and crankshaft bearing failure.

Innovation Solution

Incorporating elastic means, such as springs, between the sleeve and crankshaft bearing to absorb thermal expansions and maintain consistent contact pressures, reducing the risk of rupture and plasticization.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If the compression of the sleeve is increased to ensure gas tightness when hot, then gas tightness is improved, but cold contact pressures increase which can lead to plasticization and crankshaft bearing failure

Engineering Contradiction:
Improvegas tightnessVSAvoidcontact pressure
Core Design Contradiction:
ReliabilityVSStrength

Solution Approach 1:

The patent replaces the static compression system with a dynamic elastic support system. The sleeve is supported by elastic means (springs or elastomeric rings) that allow the contact pressure to dynamically adjust based on thermal expansion. When hot, the elastic means compress to maintain gas tightness; when cold, they relax to reduce contact pressure to safe levels, preventing plasticization and bearing failure.

Inventive Principle:
Principle #15Dynamics

Solution Approach 2:

The patent changes the physical state and mechanical properties of the support system from rigid to elastic. By introducing elastic means with specific modulus of elasticity values, the system can change its stiffness characteristics in response to temperature variations, allowing high compression when hot for sealing and low compression when cold for safety.

Inventive Principle:
Principle #35Parameter changes

2Reliability

If rigid support is used to maintain gas tightness, then sealing is achieved, but thermal expansion causes loss of tension and potential failure

Engineering Contradiction:
Improvegas tightnessVSAvoidcontact pressure stability
Core Design Contradiction:
ReliabilityVSStability of the object's composition

Solution Approach 1:

The patent employs flexible elastic elements (elastomeric rings or spring-based structures) to support the sleeve. These flexible components can deform and adapt to thermal expansion of the aluminum engine block, maintaining continuous contact and gas tightness while accommodating dimensional changes without losing tension or causing excessive stress.

Inventive Principle:
Principle #30Flexible shells and thin films

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 elastic means effectively absorb thermal expansions, ensuring improved gas tightness and reducing the risk of crankshaft bearing failure and plasticization, maintaining reliable engine operation across varying temperatures.

Implementation Method 1

Given that the engine block is made of aluminum and the sleeve 3 of cast iron, the hot thermal expansions lead to a loss of tension in the assembly

Methodology Applied
Scientific EffectThermal expansion: Thermal Expansion

Implementation Method 2

provision is made, according to the invention, for a blind internal combustion engine comprising at least one cylinder comprising a cylindrical chamber, an attached sleeve fitted into the cylindrical chamber and crankshaft bearings on which the sleeve bears, the engine further comprising elastic means forming a spring interposed between the liner and the crankshaft bearing

Methodology Applied
Scientific EffectElasticity: Elasticity

Data Source

PatentEP3092394B1Fixed-head internal combustion engine with improved gas-tightness
Publication Date: 2017.11.15 RENAULT SA
  • EP3092394B1 patent drawingFigure 1
  • EP3092394B1 patent drawingFigure 2
  • EP3092394B1 patent drawingFigure 3~4

AI summary

The invention relates to a fixed-head internal combustion engine comprising at least one cylinder having a cylindrical chamber arranged in a housing, an applied lining (3) inserted in the cylindrical chamber, and a supporting element attached to the housing (40) whereon the liner is supported, the engine also comprising elastic means (6) forming a spring, inserted between the liner and the supporting element attached to the housing, such that the liner is supported on said supporting element attached to the housing via the elastic means forming a spring.