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 2008-01-1521 E3 System - A Two speed Accessory Belt Drive System for Reduced Fuel Consumption Imtiaz Ali and Kyung-Joon Yang Gates Corporation, Gate s Unitta Korea Company Se-Jun Kim Hyundai Motor Company 2008 SAE Internati onal Powertrains, Fuels and Lubricants Congress Shanghai, China June 23-25, 2008Downloaded from SAE International by Stony Brook Univ, Monday, August 13, 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]: 724-772-4028Fax: 724-776-3036 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 © 2008 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 Stony Brook Univ, Monday, August 13, 20182008-01-1521 E3 System - A Two speed Accessory Belt Drive System for Reduced Fuel Consumption Imtiaz Ali and Kyung-Joon Yang Gates Corporation, Gates Unitta Korea Company Se-Jun Kim Hyundai Motor Company Copyright © 2008 SAE International ABSTRACT All vehicles have some or all accessories such as alternators, air conditioner compressors, power steering pumps, and water pumps. These devices are mounted on the front of the engine and are powered by a pulley mounted on the front of the crankshaft. This power represents a parasitic loss and this loss is greater at higher engine speeds. To reduce the impact of the accessories on the engine, a two speed transmission that reduces the accessories speed at off-idle conditions was designed, implemented, and tested on several vehicles. The vehicles were tested for fuel economy on the Japanese 10.15 Mode drivi ng cycle, the FTP75 city cycle, and the HWFET Highway Cycle. Results showed an average of 5% reduction in fuel consumption and a corresponding 5% in CO2 with no impact of accessory performance and vehicle drivability. Simulations with GT-Drive software was used to determine the optimum speed reduction and the threshold switching speed that maximizes fuel savings. In this paper we present the system design, its operating characteristics and results of fuel economy testing and drivability assessments. INTRODUCTION Vehicles have accessories such as air conditioner compressors, alternators, power steering pumps, and water pumps. An example is shown in Figure 1. These devices provide conditioned air to a vehicle’s cabin, produce electrical power, provi de the driver with steering assist, and cool the internal combustion engine. The accessories are mounted on the front of the engine and they are driven by a serpentine belt that connects the engine crankshaft pulley to the accessories pulleys. The brake power produced by the vehicle’s engine not only has to propel the vehicle but must also provide power to t