400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 981101 Friction Materials for Slip Clutch Applications Yih-Fang Chen Borg-Warner Automotive Reprinted From: 1998 Transmission and Driveline Systems Symposium: New Developments and Advanced Concepts in Systems and Components (SP-1324) International Congress and Exposition Detroit, Michigan February 23-26,1998Downloaded from SAE International by Swinburne Univ Of Technology, Saturday, September 08, 2018The appearance of this ISSN code at the bottom of this page indicates SAE’s consent that copies of the paper may be made for personal or internal use of specific clients. This consent is given on the condition, however, that the copier pay a $7.00 per article copy fee through the Copyright Clearance Center, Inc. Operations Center, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sec- tions 107 or 108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying for general distribution, for advertising or promotional purposes, for creating new collective works, or for resale. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Customer Sales and Satisfaction Department. Quantity reprint rates can be obtained from the Customer Sales and Satisfaction Department. To request permission to reprint a technical paper or permission to use copyrighted SAE publications in other works, contact the SAE Publications Group. No part of this publication may be reproduced in any form, in an electronic retrieval system or otherwise, without the prior wri tten permission of the publisher. ISSN 0148-7191 Copyright 1998 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the author(s) and not necessarily those of SAE. The author is solely responsible for the content of the paper. A process is available by which discussions will be printed with the paper if it is pu blished in SAE Transactions. For permission to publish this paper in full or in part, contact the SAE Publications Group. Persons wishing to submit papers to be considered for presentation or publication through SAE should send the manuscript or a 30 0 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility DatabaseDownloaded from SAE International by Swinburne Univ Of Technology, Saturday, September 08, 20181981101 Friction Materials for Slip Clutch Applications Yih-Fang Chen Borg-Warner Automotive Copyright © 1998 Society of Automotive Engineers, Inc. ABSTRACT A bench test method to evaluate the friction performance for low-speed slip clutch applications such as Electroni- cally Controlled Converter Clutch (ECCC) was devel- oped. Several friction materials were tested against different ATFs at various slip speeds and torque levels. The apply pressure, slip torque output, and torque vibra- tion (shudder) amplitude were monitored while the torque converter clutch was slipping. Two kinds of shudder phe- nomena, Green Shudder and Long-Term Shudder, were considered. The relationship between torque-speed curve slope and torque vibration amplitude is discussed. The material properties of the friction material candidates were investigated. The results suggest that the devel- oped test method, which measures the amplitude of torque vibration, is a valuable tool for predicting anti- shudder performance. The results also indicate that the torque-speed slope does not have a direct correlation to the torque vibration. In addition, a good friction material for the low-speed slip clutch should possess certain material characteristics. INTRODUCTION In the 1970s, the energy crisis started. The automotive industry began to seek alternatives for fuel economy. The to