a a fl Me Engineering" Resource ForAdvancing Mobility 400 COMMONWEALTH DRIVE WARRENDALE, PA 15096 SAE Technical Paper Series 811288 Wet Disc Brakes for Off-Highway Vehicles Vincent M. Stempien Rockwell International Truck Meeting Dearborn, Michigan November 9-12, 1981Downloaded from SAE International by Imperial College London, Monday, August 20, 2018The appearance of the code at the bottom of the first page of this paper indicates SAE's consent that copies of the paper may be made for personal or internal use, or for the personal or internal use of specific clients. This consent is given on the con- dition, however, that the copier pay the stated per article copy fee through the Copyright Clearance Center, Inc., Operations Center, 21 Congress St., Salem, MA 01970 for copying beyond that permitted by Sections 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 collec- tive works, or for resale. Papers published prior to 1978 may also be copied at a per paper fee of $2.50 under the above stated conditions. SAE routinely stocks printed papers for a period of three years following date of publication. Direct your orders to SAE Order Department. To obtain quantity reprint rates, permission to reprint a technical paper or per- mission to use copyrighted SAE publications in other works, contact the SAE Publica- tions Division. ISSN 0148-7191 Copyright C 1981 Society of Automotive Engineers, Inc.Downloaded from SAE International by Imperial College London, Monday, August 20, 2018811288 Wet Disc Brakes for Off-Highway Vehicles Vincent M. Stempien Rockwell International FOR SOME YEARS NOW, Rockwell Automo- tive Operations has produced a multi- tude of off-highway brake products centered around the traditional disc and drum concepts. The application range of these products is broad and performance has been very acceptable, but requirements for longer lining life and reduced downtime have become increasingly important. In addition, the current and impending regulatory standards concerning exposed surface temperatures for underground mining operations have been of special con- cern for this industry. To address these problems, Rockwell has develop- ed a new wet disc brake family called DURA-DISCT .M This new product is the first non-captive family-sized wet disc brake in the off-highway indus- try that can be integral or unit mounted. This paper serves both to introduce, as well as outline, thedesign and development of the Dura- Disc family. THEORY OF OPERATION The fundamental purpose of any given brake is two-fold. First to produce a retarding force and second to absorb the kinetic energy of a moving vehicle. In the case of a vehicle traveling on level ground the required retarding force is equal to the mass of the moving vehicle times the desired deceleration F = MA (1) while the kinetic energy absorbed during the brake stop is equal to one-half the mass of the vehicle times the vehicle velocity squared KE = 1/2 MV2(2) The retarding effort produced by a ABSTRACT Many of the brake applications for off-highway vehicles require the brake to operate in a hostile envir- onment such as mud slurries or abra- sive dust. While the drum and disc type brakes available today can per- form the stopping function of a brake, they may not provide the low mainten- ance or long life required in some en-vironmental extremes. A wet disc brake, however, can perform the stop- ping function as well as provide the required life because it is completely sealed from the operating environment. This paper describes the major design features and the development of the Rockwell wet disc brake. 0148-7191/81/1109-1288802.50 Copyright 1981 Society of Automotive Engineers, Inc.Downloaded from SAE International by Imperial College London, Monday, August 20, 2018APPLY FORCE COOLING FLUIDSTATIONARY DISCS ROTATING DISCS APPLIED' LIN