400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 SAE TECHNICAL PAPER SERIES 2002-01-0931 Development of Toyota’s Transaxle for Mini-van Hybrid Vehicles Tatsuya Ozeki and Mitsuhiro Umeyama Toyota Motor Corp. Reprinted From: Transmission and Driveline Systems Symposium 2002 (SP–1655) SAE 2002 World Congress Detroit, Michigan March 4-7, 2002Downloaded from SAE International by Univ of California Berkeley, Friday, July 27, 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 per article copy fee through the Copyright Clearance Center, Inc. OperationsCenter, 222 Rosewood Drive, Danvers, MA 01923 for copying beyond that permitted by Sections 107 or108 of the U.S. Copyright Law. This consent does not extend to other kinds of copying such as copying forgeneral distribution, for advertising or promotional purposes, for creating new collective works, or forresale. 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 wr itten permission of the publisher. ISSN 0148-7191 Copyright © 2002 Society of Automotive Engineers, Inc. Positions and opinions advanced in this paper are those of the aut hor(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 published 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 consi dered for presentation or publication through SAE should send the manuscript or a 3 00 word abstract of a proposed manuscript to: Se cretary, Engineering M eetings Board, SAE. Printed in USAAll SAE papers, standards, and selected books are abstracted and indexed in the Global Mobility DatabaseDownloaded from SAE International by Univ of California Berkeley, Friday, July 27, 20182002-01-0931 Development of Toyota’s Transaxle for Mini-Van Hybrid Vehicles Tatsuya Ozeki and Mitsuhiro Umeyama Toyota Motor Corp. Copyright © 2002 Society of Automotive Engineers, Inc. ABSTRACT Toyota introduced the world's first mass-produced hybrid passenger car, the Prius, in December 1997. In June2001, Toyota developed the Toyota Hybrid System-CVT(THS-C). This new hybrid system for mini-vans wasmounted on the Estima Hybrid. A new transaxle was developed for the front drive unit of the THS-C system that is compact, lightweight, and highly efficient. The unit achieves excellent drivingcomfort with smooth speed change by CVT control. High-level driving power control is provided via a wetmultiple disc clutch. This paper introduces and explains the following aspects of the THS-C system: 1. Compact and lightweight technologies 2. High-efficiency technologies3. Electronic CVT and clutch control technologies. INTRODUCTION CO2 emissions reduction through enhanced fueleconomy and clean exhaust emissions are importantdevelopment themes in the automobile industry. A dual benefit to the environment is achieved by alleviating global warming and also by preventing pollution. A hybrid system that incorporates an electric motor is an effective means of improving fuel economy. The ToyotaHybrid System (THS) is such a system and it has beendeveloped and incorporated in mass-produced passenger cars. Mini-vans with large and heavy bodies typically have lower fuel economies than passenger cars .Thus the merits of developing a hybrid type mini-van aresubstantial. Toyota’s THS-C (Fig.1) is the mos