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 2007-01-2408 SAE Standard Procedure J2747 for Measuring Hydraulic Pump Airborne Noise Christian Fernholz and Tim Offerle Ford Motor Company Robert Beyerlein Delphi Corporation William Stevenson Roush Industries, Incorporated Michelle Wood General Motors Corporation Noise and Vibration Conference and Exhibition St. Charles, Illinois May 15-17, 2007Downloaded from SAE International by University of Liverpool, Sunday, September 09, 2018The Engineering Meetings Board has approved this paper for publication. It has successfully completed SAE's peer review process under th e supervision of the session organi zer. This process requires a minimum of three (3) reviews by industry experts. 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]: 724-772-4028 Fax: 724-776-3036 For multiple print copies contact: SAE Customer Service Tel: 877-606-7323 (inside USA and Canada)Tel: 724-776-4970 (outside USA)Fax: 724-776-0790Email: [email protected] ISSN 0148-7191 Copyright © 2007 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 th e 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 publicat ion by SAE should send the manuscript or a 300 word abstract to Secretary, Engineering Meetings Board, SAE. Printed in USADownloaded from SAE International by University of Liverpool, Sunday, September 09, 2018ABSTRACT This work discusses the development of SAE procedure J2747, “Hydraulic PumpAirborne Noise Bench Test”. This is a test procedure describing a standard method for measuring radiated sound power levels fromhydraulic pumps of the type typically used inautomotive power steering systems, thoughit can be extended for use with other types of pumps. This standard was developed by a committee of industry representatives fromOEM’s, suppliers and NVH testing firmsfamiliar with NVH measurementrequirements for automotive hydraulicpumps. Details of the test standard are discussed. The hardware configuration of the testbench and the configuration of the testarticle are described. Test conditions, dataacquisition and post-processing specificsare also included. Contextual information regarding the reasoning and priorities applied by the development committee isprovided to further explain the strengths,limitations and intended usage of the testprocedure. Lastly, continuing actions with respect to further development of this standard as well as additional test standardsfor hydraulic pump NVH are discussed. INTRODUCTION The development of ever-quieter road vehicles has demanded comparableimprovements in the NVH performance ofthe subsystems which are used in thesevehicles. Hydraulic steering systemsrepresent just such a case. Noise characteristics of these systems are generally not considered to be a “tuneable”or positive identifying feature of the vehicle.Rather, automotive manufacturers generallyprefer that steering systems make no audible noise at all. Consequently, manufacturers and OEM’s alike haveconsistently striven for quieter and quietersteering systems and components. An important parameter in quantifying noise levels produced by a hydraulic steering system is the amount of airborne noise produced by the steering pump. Thismeasurement is an indicator of how muchnoise a steering system in gene