400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-0790 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2007-01-1101 Toyota's World First 8-Speed Automatic Transmission for Passenger Cars Hirofumi Ota, Kazutoshi Nozaki, Toyota Motor Corp. Aisin AW Co., Ltd. Reprinted Fr om: Tr ansmissions & Drivelines (SP-2134) 2007 World Congress Detroit, Michigan April 16-19, 2007 Atsushi Honda and Masafumi Kinoshita Toshihiko Aoki, Minoru Todo and Mikio IwaseDownloaded from SAE International by Columbia Univ, Monday, August 20, 2018By mandate of the Engin eering Meetings Board, th is paper has been approved for SAE publication upon completion of a peer review process by a minimum of three (3) industry experts under the supervision of the session organizer. All rights reserved. No part of this publication may be reproduced, stored in a retrieval system, or transmitted, in any form or by any means, electronic, mechanical, photocopying, recording, or otherwise,without the prior written permission of SAE. For permission and licensing requests contact: SAE Permissions 400 Commonwealth DriveWarrendale, PA 15096-0001-USAEmail: [email protected]: 724-776-3036Tel: 724-772-4028 For multiple print copies contact: SAE Customer ServiceTel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: Customer [email protected] ISSN 0148-7191Copyright © 2007 SAE InternationalPositions 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 pap er if it is publishe d in SAE Transactions. Persons wishing to submit papers to be considered for presentation or publication by SAE should send themanuscript or a 300 word abstract of a proposed manuscript to: Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by Columbia Univ, Monday, August 20, 2018Copyright © 2007 SAE International ABSTRACT TOYOTA has developed the world's first eight-speed automatic transmission (AA80E) for front-engine, rear- drive passenger cars. The AA80E developed for high- torque engines raises the level of power performance and fuel efficiency. To meet the size requirements needed for mounting in a passenger car application, an 8-speed geartrain, torque converter, transmission case and hydraulic control device were all newly-developed. Furthermore, the AA80E has benefited from technical developments to achieve an extremely high level of quietness and shifting performance. In this paper, the details of the AA80E are introduced. INTRODUCTION Because of recent developments such as global warming and energy issues on a global scale, it has become essential to develop cars with a greater degree of fuel efficiency and cleaner exhaust gas. Moreover, higher performance powertrain systems are being developed at a time that higher mobility and speed are being sought in the premium car market. Technology which can combine all of these appare ntly conflicting features is now being sought. The AA80E automatic transmission(AT) was developed for the new LS460, not only to improve the above-mentioned basic performance but also to achieve high-quality quietness, drivability, and shifting performance. In order to meet these requirements, the world's first 8- speed automatic transmission was developed. Details of a geartrain that brings out the best performance in high- powered and high-torque engines with a compact and lightweight transmission size will now be presented. A low gear noise te chnology and a va riety of items representative of technical developments in a control system that makes good shifting performance will also be described. DEVELOPMENT OBJECTIVES The qualities set out below have been developed as the main objectives. 1. Enhancement of fuel efficiency and power performance 2. Reduc