Double-Layer Wet Friction Material With Cellulose for Wet Strength
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Solution Overview
Problem
Existing wet-type friction materials in clutches and transmissions face challenges in maintaining strength and durability in oil-submerged environments, particularly in paper-based materials used in torque converters.
Innovation Solution
A method involving a cellulose layer coated with a friction coating, followed by a matrix of fibers and filler particles bonded with a binder, forming a wet friction material base layer, which is then integrated with a metal part to enhance strength and durability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If paper-based friction material is used in wet-type clutches, then the material can be easily manufactured and processed, but the strength and durability in oil-submerged environments deteriorates
Solution Approach 1:
The patent applies composite materials by combining cellulose fibers with synthetic binders (polyester, polyacrylonitrile, or polyacrylic acid) to create a friction material that maintains the ease of paper-based manufacturing while significantly improving wet strength and durability in oil-submerged environments. The composite structure allows the material to be processed like traditional paper while gaining enhanced mechanical properties.
Solution Approach 2:
The patent changes the chemical and physical parameters of the friction material by controlling fiber composition (70-90% cellulose), binder content (5-20% of dry weight), and processing conditions (pH 4-7, temperature 20-100°C). These parameter changes transform the material properties to achieve both manufacturability and improved wet strength without requiring complex manufacturing processes.
2Device complexity
If traditional friction material structure is used, then the manufacturing process is simple, but the wet strength is insufficient for durable operation
Solution Approach 1:
The patent improves wet strength by changing key parameters: using 70-90% cellulose fibers instead of traditional paper, adding 5-20% synthetic binder by dry weight, and controlling processing at pH 4-7 and temperatures of 20-100°C. These parameter modifications enhance wet strength while keeping the manufacturing process relatively simple and structure not overly complex.
3Ease of manufacture
If paper-based material is used in wet friction clutches, then the material can be easily processed, but the strength and durability in oil-submerged environments deteriorates
Solution Approach 1:
The patent creates a composite friction material combining cellulose fibers with synthetic binders that maintain the ease of processing associated with paper-based materials while dramatically improving strength in oil-submerged environments. The composite structure allows traditional processing methods to be used while achieving superior mechanical properties.
Solution Approach 2:
The patent changes material parameters including fiber composition (70-90% cellulose), binder content (5-20% of dry weight), and processing conditions (pH 4-7, temperature 20-100°C) to achieve both ease of processing and enhanced strength in wet, oil-submerged conditions without complicating the manufacturing process.
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 cellulose-enhanced wet friction material exhibits improved wet strength and durability, suitable for use in torque converters and transmissions, enhancing the performance of friction clutches.
Implementation Method 1
saturating the matrix of fibers and filler particles with a binder and curing the binder to join the matrix of fibers and filler particles together
Implementation Method 2
The coating of the first outer surface of the cellulose layer with the friction coating may include spraying, brushing or rolling the friction solution onto the outer surface of the cellulose layer
Implementation Method 3
The friction material in wet-type friction clutches generally operates in an oil submerged environment
Data Source
AI summary
A method of making a wet friction material includes coating a first outer surface of a cellulose layer with a friction coating; placing a matrix of fibers and filler particles on a second outer surface of the cellulose layer; and saturating the matrix of fibers and filler particles with a binder and curing the binder to join the matrix of fibers and filler particles together to form a wet friction material base layer and to join wet friction material base layer to the second outer surface of the cellulose layer.