Amine Derivative Friction Modifiers for Automatic Transmission Shudder
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Solution Overview
Problem
Automatic transmission fluids face challenges in achieving a high static coefficient of friction and durable positive slope in the µ-V curve, which is essential for preventing transmission shudder, as traditional friction modifiers often result in low static friction and lack durability.
Innovation Solution
A lubricant composition comprising an oil of lubricating viscosity and 0.1 to 10 weight percent of a hydrocarbyl amine with a hydrocarbyl group of 12 to 22 carbon atoms, specifically designed to provide improved friction characteristics, including a high static coefficient of friction and durable positive slope, thereby addressing the limitations of traditional friction modifiers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If traditional friction modifiers are used in automatic transmission fluids, then the fluid can provide some friction modification, but the static coefficient of friction becomes low and the positive slope durability is insufficient
Solution Approach 1:
The patent changes the chemical structure parameters of the friction modifier by specifying particular amine derivatives with defined molecular weights (500-5000) and hydrocarbyl group compositions (12-22 carbon atoms). These parameter changes enable the friction modifier to simultaneously achieve high static coefficient of friction and durable positive slope characteristics, resolving the contradiction between initial friction performance and long-term durability.
Solution Approach 2:
The patent creates a composite friction modification system by combining specific amine derivatives with automatic transmission base fluids. The composite nature of this formulation, with carefully selected additive concentrations (0.1-10 weight percent), enables both high static friction and sustained positive slope performance that neither component could achieve alone, thus resolving the technical contradiction.
2Force
If the friction modifier provides high static coefficient of friction, then clutch holding capacity improves, but the positive slope durability decreases
Solution Approach 1:
The patent optimizes molecular weight parameters (500-5000 range) and hydrocarbyl group composition (12-22 carbon atoms) of the amine derivative friction modifier. These parameter changes create a molecular structure that adheres strongly to friction surfaces for high clutch holding capacity while maintaining stable film properties over time for durable positive slope, thus resolving the contradiction between initial force and duration.
3Reliability
If traditional friction modifiers are used, then the formulation is simple and cost-effective, but the anti-shudder performance is insufficient
Solution Approach 1:
The patent defines specific parameter ranges for the friction modifier (molecular weight 500-5000, hydrocarbyl carbon atoms 12-22, concentration 0.1-10 weight percent) that optimize anti-shudder performance. By changing these parameters within defined boundaries rather than requiring complex multi-component systems, the patent achieves superior anti-shudder performance while maintaining formulation simplicity.
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 lubricant composition effectively maintains a positive slope over time, reducing the likelihood of transmission shudder and ensuring anti-shudder durability, as demonstrated by the variable speed friction tester results.
Implementation Method 1
The additive comprises a Component-1 formed by condensing a polyamine with an aliphatic monoacid
Implementation Method 2
A lubricant composition comprising an oil of lubricating viscosity and 0.1 to 10 weight percent of a hydrocarbyl amine
Data Source
AI summary
A composition useful for lubricating an automatic transmission comprises an oil of lubricating viscosity and a hydrocarbyl amine with a hydrocarbyl group of 12 to 22 carbon atoms and having one or two additional groups of the structure -R3-NHC(O)R4, wherein R3 is an alkylene group of 1 to 4 carbon atoms and R4 is a hydrocarbyl group of 4 to 22 carbon atoms, or a nitrogen-containing heterocyclic group, or an aminoalkyl group. The hydrocarbyl amine does not contain a primary amino group.