Chain Guide Sliding Layer With Low-Friction Polyamide
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Solution Overview
Problem
Sliding elements in chain-driven internal combustion engines experience significant energy loss due to friction, particularly at elevated temperatures, which affects fuel efficiency and CO2 emissions, and existing solutions like adding solid lubricants to polyamide polymers compromise strength and impact resistance.
Innovation Solution
A sliding element with a surface layer made of semi-crystalline polyamide having a tensile modulus of at least 800 MPa, combined with optional inorganic fillers and fibres, reduces friction coefficients under lubricated conditions, enhancing heat resistance, fatigue, and impact properties.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of energy
If solid lubricants are added to polyamide polymers to reduce friction, then the coefficient of friction decreases, but the strength and impact resistance of the material deteriorate
Solution Approach 1:
The patent changes the material parameters by using a specific polyamide blend composition (polyamide 6 and polyamide 12 in a weight ratio of 95:5 to 50:50) to achieve optimal balance between friction reduction and mechanical strength. This parameter optimization allows the material to maintain high impact resistance while exhibiting low friction coefficients under lubricated conditions, resolving the contradiction between reducing friction loss and maintaining strength.
2Temperature
If sliding components are designed for high temperature operation, then heat resistance improves, but material selection and manufacturing complexity increase
Solution Approach 1:
The patent employs a composite material system consisting of a polyamide 6/polyamide 12 blend combined with specific lubricants and additives. This composite approach enables the sliding component to withstand high temperatures (up to 100°C and beyond) while maintaining appropriate friction characteristics. The composite formulation achieves heat resistance without requiring complex cooling systems or multiple separate components, thus managing manufacturing complexity.
3Stability of the object's composition
If the tensile modulus of the polyamide is increased to improve rigidity, then sliding stability improves, but the material becomes more brittle and impact resistance decreases
Solution Approach 1:
The patent optimizes the tensile modulus parameter by controlling the polyamide blend ratio and adding specific modifiers to achieve a balance between sliding stability and impact resistance. The polyamide 6/polyamide 12 blend system allows adjustment of rigidity while maintaining toughness, enabling the sliding component to exhibit stable sliding characteristics without becoming overly brittle.
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 significantly reduces energy consumption in power train drive systems by lowering the coefficient of friction under lubricated conditions, improving the efficiency and durability of sliding components in chain guides and tensioners.
Implementation Method 1
A sliding element with a surface layer made of semi-crystalline polyamide having a tensile modulus of at least 800 MPa, combined with optional inorganic fillers and fibres, reduces friction coefficients under lubricated conditions
Data Source
AI summary
The invention relates to a chain guide, respectively a chain tensioner for use in a lubricated sliding system, comprising a surface layer or bearing or comprising a sliding element comprising a surface layer, the surface layer being mainly made of a polymeric material containing a matrix polymer and optionally other components dispersed in said matrix polymer, wherein the matrix polymer consists of a semi-crystalline polyamide (SCPA) having a tensile modulus at 140° C. of at least 800 MPa (measured by the method according to ISO 527-1A). The invention also relates to a power train drive system comprising an engine, a transmission differential and a drive shaft system, a drive chain and a plastic component comprising a sliding element in contact with the lubricated drive chain, wherein the chain guide, the chain tensioner, respectively the sliding element has a coefficient of friction (CoF), measured in lubrication oil at 140° C. at a nominal contact pressure of 1 MPa and a speed of 1 m/s, of at most 0.07.