400 Commonwealth Drive, Warrendale, PA 15096-0001 U.S.A. Tel: (724) 776-4841 Fax: (724) 776-5760 Web: www.sae.org SAE TECHNICAL PAPER SERIES 2003-01-0596 ZF 6-Speed Automatic Transmission for Passenger Cars Heribert Scherer Division Car Driveline Techno logy, ZF Friedrichshafen AG Reprinted From: Transmission & Driveline System s Symposium 2003 (SP-1760) 2003 SAE World Congress Detroit, Michigan March 3-6, 2003Downloaded from SAE International by American Univ of Beirut, Sunday, July 29, 2018All 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]: 724-772-4891Tel: 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: 724-776-1615Email: Customer [email protected] ISSN 0148-7191Copyright © 2003 SAE International 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 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 American Univ of Beirut, Sunday, July 29, 20182003-01-0596 ZF 6-Speed Automatic Transmission for Passenger Cars Heribert Scherer Division Car Driveline Technology, ZF Friedrichshafen AG Copyright © 2003 SAE International ABSTRACT With the introduction of the ZF “myTronic6” (6 HP 26) in 2001, the Division Car Driveline Technology of the ZF Friedrichshafen AG has developed and introduced anew 6 speed stepped automatic transmission forpassenger cars. This paper describes the gear setconcept, the mechanical design and specific functions ofthis transmission. The 6 HP 26 is part of the new 6-speed program which comprises 3 transmission types. Itwill replace the existing ZF 5 s peed program completely within the next years. INTRODUCTION In the European market, 5 speed automatictransmissions are state of the art in the midsize andupper class car segment since the beginning of the 90’s.In comparison to the world wide market, where4 speed transmissions st ill have the bi ggest volume, these transmissions represent a high quality standardand their contribution to fuel efficiency, reduction ofnoise and emissions, improved performance and drivingcomfort has led to a constant increase of the marketshare. The aspect of fuel efficiency is gaining importance in the requirements of future transmission systems. Thereforeall transmission producers and suppliers areinvestigating new concepts like automated manualtransmissions, double clutch systems or different typesof continuously variable transmissions to be preparedfor future applications. For the stepped transmissionstypes, these requirements need to provide a biggeroverall ratio spread and improve the efficiencyaccordingly. In addition, transmission functions need tobe developed or improved to support those targets. Basically, it was necessary to find a transmission concept, which provides an overall ratio spread of about6.0. Calculation and simulation results clearlydemonstrated that it was necessary to be able to dividethis range by 6 gears. The table below shows the rangefrom 3 to 6 speed transmissions. • 3 speed ϕ tot 2,3 to 2,8 • 4 speed ϕ tot 2,7 to 4,2 • 5 speed ϕ tot 4,2 to 5,2 • 6 speed ϕ tot 6,0 From the previous 3 speeds to the latest 5 speed transmissions, there was not only an increase of ratioand gears,