Porous wet friction material utilizing a compliant epoxide resin binder system

Abstract

A wet friction material is disclosed bonded to a plate for transmission of motion, with the friction material made up of a porous fiber substrate, which is at least partially impregnated with a catalyzed resorcinol diglycidyl ether resin to improve friction properties.

Description

CROSS R FER NC[0001] The present invention claims the priority of U.S. Provisional Application No. 60 / 439,875, filed Jan. 14, 2003.[0002] The term "wet friction material" is well understood by those skilled in the art. These materials typically use a porous substrate comprising fibers such as wet laid cellulose and possible other additives. Rings of this substrate are typically mounted on each side of a ring-shaped metal support disk. The substrate is partially impregnated with a curable resin dissolved in a solvent with the resin most widely used being a phenol type. In a standard transmission or clutch, these members are mounted in an interleaved relation with bare metal reaction disks or plates, and the assembly can be moved in and out of engagement, for example, to provide a shifting or braking function in a vehicle. These assemblies run in lubricating liquids to provide, among other things, a cooling function.[0003] In wet friction materials, it is desirable to have as high of ...

AI Technical Summary

Benefits of technology

[0008] In general, a high coefficient of friction is desirable because more torque can be transmitted to a transmission with a given friction surface area. This may allow design of transmission with fewer friction plates, saving weight and space. While most paper substrates and transmission fluids contain elements to modify friction coefficient, the RDGE binder provides additional performance benefits, as well as a dynamic coefficient of friction of 0.17 and greater.

Problems solved by technology

Unmodified, these resins are brittle and have relatively high modulus.

However, even extensive modification does not fully overcome the inherent brittle nature of phenolic systems.

There are both chemical and practical limitations, such as solution viscosity, which govern the possible extent of chemical modification of these systems.