Wet Clutch Friction Modifier Composition for Stable Torque Capacity
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Solution Overview
Problem
Lubricating oil compositions for automatic transmissions face challenges in maintaining optimal friction characteristics and durability of wet clutches, particularly with the transition from cellulose-rich to aramid-rich papers, leading to power loss, vibration, and noise due to insufficient anti-wear and friction modifying additives.
Innovation Solution
A lubricating oil composition comprising a major amount of lubricating viscosity oil and dispersant friction modifiers with specific hydrocarbyl radicals, including polyisobutenyl groups, to enhance friction stability and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If aramid-rich wet clutch papers are used, then durability performance is improved, but cost increases
Solution Approach 1:
The patent introduces friction modifying additives as intermediary substances that mediate between the aramid-rich clutch paper and the lubricant. These additives adsorb onto the clutch paper surface and provide the necessary friction characteristics, allowing the use of expensive aramid paper while controlling overall system cost through optimized additive selection rather than relying solely on cellulose-rich papers
Solution Approach 2:
The patent modifies the chemical and physical parameters of the lubricant by incorporating specific friction modifying additives with controlled molecular structures and concentrations. This parameter change enables the lubricant to effectively interact with aramid fibers, providing durable friction performance without requiring excessive amounts of expensive aramid material
2Reliability
If sufficient anti-wear and friction modifying additives are used, then wet clutch performance is improved, but lubricant formulation complexity increases
Solution Approach 1:
The patent develops friction modifying additives that serve multiple functions simultaneously: they provide friction modification, anti-wear protection, and thermal stability. By using multi-functional additives rather than separate specialized additives for each function, the lubricant formulation achieves comprehensive wet clutch performance protection while reducing overall formulation complexity
Solution Approach 2:
The patent creates composite lubricant formulations by combining base lubricant oils with specifically selected friction modifying additives in optimized ratios. This composite approach integrates multiple protective functions into a single unified lubricant system, achieving superior wet clutch performance without proportionally increasing formulation complexity
3Quantity of substance
If cellulose-rich wet clutch papers are used, then manufacturing cost is reduced, but friction performance and thermal stability deteriorate
Solution Approach 1:
The patent employs friction modifying additives that can be easily replaced or replenished in the lubricant system. Rather than relying on expensive aramid paper as the primary friction element, the system uses more economical lubricant additives that provide the necessary friction performance and can be economically managed through regular lubricant changes, effectively treating the friction modification function as a consumable rather than a permanent component
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 composition improves static friction coefficient and maintains prolonged dynamic friction coefficient stability, ensuring excellent wet clutch torque capacity and durability.
Implementation Method 1
Additive effects are caused by both their physical and chemical absorption on the clutch materials, e.g., cellulose, aramid (natural and synthesized) fibers, silica and steel plate surface
Data Source
AI summary
A lubricating oil composition is disclosed. The composition includes a major amount of an oil of lubricating viscosity and one or more dispersant friction modifiers given by Structure A,R1, and R3 are independently a linear or branched-chain monovalent hydrocarbyl radical of 4 to 100 carbon atoms; x is from 1 to 3; and y is from 1 to 3; R2 is a linear or branched-chain monovalent hydrocarbyl radical of 4 to 100 carbon atoms or hydrogen; and at least one of R1, R2, and R3 is a polyisobutenyl group having a molecular weight of 500 or greater.