SA E TECHNICAL PAPER SERIES Theoretical Investigation on Automatic Transmission Efficiency Dong Hoon Park, Tae Seok Seo, Do GI Lrm, and Hee Bock Cho Hyunda~ Motor Co Reprinted from. Transmlssron and Drlvelrne Systems Symposrum Effrcrency, Components, and Materials (SP-1154) The Engrneerrng Socrety EA =For Advancrng Mobrlrty and Sea Av and Space, lnternatronal Congress & Exposrtion Detrolt, M~chrgan February 26-29,1996 400 Commonwealth Drlve, Warrendale, PA 15096-0001 U.S A Tel: (412)776-4841 Fax.(412)776-5760 Downloaded from SAE International by North Carolina State Univ, Tuesday, September 18, 2018Theappearanceofthe ISSNcode atthe bottomofthlspage lndlcates SAE'sconsent that comes of me DaDer mav be made for ~ersonal or Internal use of swwfic cllems ~hiscdnsent~s~~er~onth&ndit~onhowever,thatthem~~er~a~a$? 00permde copy fee through the Copyr~ght Clearance Center, Inc Operabons Center, 222 Rosewood Dnve, Danvers, MAOl923forwpylng beyondthat permmed by Secbons 107 or 108 of U S Copyright Law Thls consent does not extend to other knds of copying such as copylng for general dlstnbubon, for advetttsmg or prornobonal purposes, for creabng new collect~e works, or for resale SAE roubnely stocks pnnted papers for a penod of three years followng date of publication D~rect your orders to SAE Customer Sales and Sattsfaction Department Quantlty repnnt rates can be obtruned from the Customer Sales and Sabsfachon Depaltment To request perrnlsslon to repnnt a technlml paper or permlsslon to use copyrighted SAE publlcabons In other works, contact the SAE Publ~cabons Gmup All SAE pepem, Stmdam's and selected bwks are abmacted and Indexed In Lhe Global Mob~Iny Darabase No part of this publlcabon may be reproduced In any form, in an electmnlc retneval system or otherwise, wrthout the pnor wntten permrssion of the publffiher ISSN 0148-7191 Copyright 1996 Soc~ety of Autornobve Engineers, Inc Posmons and oplnlons advanced In this paper are those of the author@) and not necessarily those of SAE The author is solely responsible for the content of the paper A process IS avalable by whlch dlscu&ions will be pnnted wlth the paper if it IS publ~shed in SAE Transactrons For permlsslon to publlsh thls paper In full or In part, Wntact the SAE Publ~cabons Group Persons wlshlng to submit papers to be considered for presentat~on or publlcatton through SAE should send the manuscnpt or a 300 word abstract of a proposed manuscnpt to Secretary, Englneenng Meebngs Board, SAE Pnnted ~n USA 9~~9 Downloaded from SAE International by North Carolina State Univ, Tuesday, September 18, 2018Theoretical Investigation on Automatic Transmission Efficiency Dong Hoon Park, Tae Seok Seo, Do GI Lim, and Hee Bock Cho Hyunda~ Motor Co Copynght 1996 Soc~eiyof AutomotNe Englneen, Inc Thls paper ~nboduces mthemabcal equahons for poww loss calwlahons of major automat~c transrmss~on components It also presents a theoretical ~nvesbgation on contnbuttonrs of each wmponenYs pawer loss to tramsslon total power losses A computer program for automabc transrmsslon effic~ncy calwlabon has been developed based on mathermt~cal equabons Effiaency calculations for the Hyundru PABn electron~c 4 speed automat~c transmss~on has been executed in order to willdate the program The calculated effiuency under vanous input and operating condit~ons - such as dflerent lnput toque & RPM, tmnsmsslon gear state, ATF temperature, toque conwter clutch ordoff - showed quite good ag-nt \nnth the test results The effic~ency charactensttcs of automattc trallsm~sston is quite complex and it changes sensrbvely to the input condrbons and tramsslon oDerahng state Ths is because there are so mny components and related MnabIes In the transmrsslon that affect the effinency As an attempt to analyze the effiaency charactenstics more systemat~cally, the mthenrabcal equations represenhng power or toque 105s of the ma~or components m automabc tramsnon wae