ISO/TS TECHNICAL SPECIFICATION 31657-3 First edition 2020-06 Plain bearings Hydrodynamic plain journal bearings under steady-state conditions - Part 3: Functions for calculation of tilting pad journal bearings Reference number IS0/TS 31657-3:2020(E) ISO @ IS0 2020 IS0/TS 31657-3:2020(E) COPYRIGHT PROTECTED DOCUMENT @ IS0 2020 All rights reserved. Unless otherwise specified, or required in the context of its implementation, no part of this publication may be reproduced or utilized otherwise in any form or by any means, electronic or mechanical, including photocopying, or posting below or Iso's memberbody in the country ofthe requester. ISO copyright office CP 401 · Ch. de Blandonnet 8 CH-1214 Vernier, Geneva Phone: +41 22 749 0111 Email: [email protected] Website: www.iso.org Published in Switzerland ii @ IS0 2020 - All rights reserved IS0/TS 31657-3:2020(E) Contents Page Foreword ..iv 1 Scope .1 2 Normative references. ..1 3 Terms and definitions 4 Functions for calculation of multi-lobed journal bearings 4.1 General.. 4.2 Tilting-pad journal bearings with four tilting pads. 4.3 Tilting-pad journal bearings with five tilting pads. .39 Annex A (informative) Characteristic curves for tilting-pad bearings with five pads ..62 Bibliography .73 @ IS0 2020 - All rights reserved iii IS0/TS31657-3:2020(E) Foreword Iso (the International Organization for Standardization) is a worldwide federation of national standards bodies (IsO member bodies). The work of preparing International Standards is normally carried out throughIsotechnicalcommittees.Eachmemberbodyinterestedinasubjectforwhichatechnical committee has been established has the right to be represented on that committee. International organizations, governmental and non-governmental, in liaison with Iso, also take part in the work. IsO collaborates closely with the International Electrotechnical Commission (IEC) on all matters of electrotechnical standardization. The procedures used to develop this document and those intended for its further maintenance are described in the ISO/IE Directives, Part 1. In particular, the different approval criteria needed for the different types of IsO documents should be noted. This document was drafted in accordance with the editorial rules of the ISO/IEC Directives, Part 2 (see www.iso.org/directives). Attention is drawn to the possibility that some of the elements of this document may be the subject of patent rights. IsO shall not be held responsible for identifying any or all such patent rights. Details of anypatentrightsidentifiedduringthedevelopmentofthedocumentwillbeintheIntroductionand/or on the ISo list of patent declarations received (see www.iso.org/patents). Any trade name used in this document is information given for the convenience of users and does not constituteanendorsement. For an explanation of the voluntary nature of standards, the meaning of IsO specific terms and expressions related to conformity assessment, as well as information about Iso's adherence to the World Trade Organization (WTO) principles in the Technical Barriers to Trade (TBT), see WWW.iso.org/ iso/foreword.html This document was prepared by Technical Committee ISO/TC 123, Plain bearings, Subcommittee SC 8, Calculation methods for plain bearings and their applications. A list of all parts in the ISO/TS 31657 series can be found on the ISO website. Any feedback or questions on this document should be directed to the user's national standards body. A complete listing of these bodies can be found at www.iso.org/members.html. iv @ IS0 2020 - All rights reserved IS0/TS 31657-3:2020(E) TECHNICAL SPECIFICATION Plain bearings - Hydrodynamic plain journal bearings under steady-state conditions Part 3: Functions for calculation of tilting pad journal bearings 1 Scope This document specifies the characteristic values for selected tilting-pad journal bearings with four or five centrally or eccentrically supported tilting pads and with angular spans of pad sliding surface