Fundamental of Ftuid Fitm Lubrication Second Edition Bernard J Hamrock Steven R Schmid mverA'ffy o/Wofrg Dctw^ Dame, 7na*;aMa, (/.&/4 BoO Jacobson MARCEL MARCEL DEKKER, INC Copyright © 2004 Marcel Dekker, Inc NEW YORK * BASEL First edition was published as FMn&wMeM?of Congress Cataioging-in-Pub!ication Data A catalog record for this book is available from the Library of Congress ISBN: 0-8247-5371-2 This book is printed on acid-free paper Headquarters Marcel Dekker, Inc., 270 Madison Avenue, New York, NY 10016, U.S.A tel: 2)2-696-9000; fax: 212-685^540 Distribution and Customer Service Marcel Dekker, Inc., Cimarron Road, Monticello, New York 12701, U.S.A tel: 800-228-1160; fax: 845-796-1772 Eastern Hemisphere Distribution Marcel Dekker AG, Hutgasse 4, Postfach 812, CH-4001 Basel, Switzerland tel: 41-61-260-6300; fax: 41-61-260-6333 Wortd Wide Web http://www.dekker.com The publisher offers discounts on this book when ordered in bulk quantities For more information, write to Special Sales/Professional Marketing at the headquarters address above Copyright @ 2004 by Marcei Dekker, Inc AH Rights Reserved Neither this book nor any part may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, microfilming, and recording, or by any information storage and retrieval system, without permission in writing from the publisher Current printing (last digit): 10 PRINTED IN THE UNITED STATES OF AMERICA Copyright © 2004 Marcel Dekker, Inc MECHANICAL ENGINEERING A Series of Textbooks and Reference Books L L Faulkner 10 11 12 13 14 15 16 17 18 19 20 21 22 23 Spr/ngr Des/y/?er's /Vartt/oooAr, Harold Carlson Co/7ip(yfe/*-/4/#ecf Grap/?/cs a/?o* Des/p/i, Daniel L Ryan At/Ar/caf/br; Pt/ndamenfa/s, J George Wills So/a/* &7[...]... 2004 Marcel Dekker, Inc FUNDAMENTALS OF FLUID FILM LUBRICATION Boundary film Bulk lubricant (c) Figure 1.7: Film conditions of lubrication regimes, (a) Fluid film lubrication surfaces separated by a bulk lubricant film; (b) partial lubrication - both bulk lubricant and boundary Aim play a role; (c) boundary lubrication - performance depends entirely on boundary Him surface films vary in thickness from... Dekker, Inc FUNDAMENTALS OF FLUID FILM LUBRICATION progress has been made in understanding the mechanism of elastohydrodynamic lubrication, generally viewed as reaching maturity Since 1970 it has been recognized that between fluid film and boundary lubrication some combined mode of action can occur This mode is generally termed "partial lubrication" or is sometimes referred to as "mixed lubrication. "... of elastohydrodynamic lubrication begins with the consideration of elasticity effects in Chapters 17 and 18 Elastohydrodynamic lubrication of rectangular conjunctions is considered in Chapter 19 and of elliptical conjunctions in Chapter 20 Film thicknesses for different fluid film lubrication regimes are presented in Chapter 21 In Chapters 22 and 23 the theory of lubrication is applied to a range of. .. application of the theory to the design of machine elements that use fluid film lubrication helps the development of the material of the text It is, however, not intended to consider all types of machine element and all types of bearing within this text Rather I hope that the understanding gained from this book will enable the reader to properly analyze any machine element that uses fluid film lubrication. .. improving their lubrication, friction, and wear practices 1 Copyright © 2004 Marcel Dekker, Inc FUNDAMENTALS OF FLUID FILM LUBRICATION Journal- \ ^Sleeve Figure 1.1: Conformal Surfaces [.R"om RamroeA; ana* /lna*er.9on Outer ^ing- Rolling element^ ^y^^^- ^_^^ ring Figure 1.2: Nonconformal Surfaces fFro?n RantroeA; awcf This book focuses on the fundamentals of fluid Aim lubrication Fluid Him lubrication. .. Elastohydrodynamic Lubrication Elastohydrodynamic lubrication (EHL) is a form of hydrodynamic lubrication where elastic deformation of the lubricated surfaces becomes significant The i '; of pressure development for hydrodynamic lubrication, (a) Slider bearing; (b) squeeze Aim bearing; (c) externally pressurized bearing Copyright © 2004 Marcel Dekker, Inc FUNDAMENTALS OF FLUID FILM. .. Problems 12 Hydrodynamic Squeeze Film Bearings 12.Introduction 12.2 Parallel-Surface Bearing of Infinite Width 12.3 Journal Bearing Copyright © 2004 Marcel Dekker, Inc FUNDAMENTALS OF FLUID FILM LUBRICATION 12.4 Parallel Circular Plate 12.5 Infinitely Long Cylinder Near a Plane 12.6 Closure 12.7 Problems 13 Hydrostatic Lubrication 13.Introduction 13.2 Formation of Fluid Film 13.3 Pressure Distribution... Inc Figure 1.9: Wear rates for various lubrication regimes [From Reer- 10 FUNDAMENTALS OF FLUID FILM LUBRICATION continuous protective layers on surfaces Boundary lubrication as discussed in this chapter is focused upon traditional machine design and manufacturing applications of fluid fUm lubrication Applications in the MEMS area are still applicable to many of the issues discussed in this chapter,... sliding They concluded that under such circumstances the chemical composition of the Huid is important, and they introduced the term "boundary lubrication. " Boundary lubrication is at the opposite end of the lubrication spectrum from hydrodynamic lubrication In boundary lubrication the physical and chemical properties of thin films of molecular proportions and the surfaces to which they are attached determine... asperity contact The contact lubrication mechanism is governed by the physical and chemical properties of thin surface films of molecular proportions The properties of the bulk lubricant are of minor importance, and the friction coefficient is essentially independent of fluid viscosity The frictional characteristics are determined by the properties of the solids and the lubricant film at the common interfaces