Michael D. Sidman, Ph.D.
`6120 Wilson Road
`Colorado Springs, CO 80919 USA
`
`Dictionary of
`Mechanical Engineering
`Fourth Edition
`
`G.H.F. Nayler
`MSc, CEng, MIMechE, MRAeS
`
`Society of Automotive Engineers, Inc.
`Warrendale, Pa.
`
`Butterworth-Heinemann
`Oxford Boston
`Johannesburg
`Melbourne New Delhi
`Singapore
`
`1
`
` Micro Motion 1013
`
`

`
`First published by George Newnes Ltd, 1967
`Second edition 1975
`reprinted 1978,1981
`Third edition 1985
`
`Copyright © 1967, 1975, 1985, 1996 G.H.F. Nayler
`
`Printed and bound in the United States of America.
`
`Butterworth-Heinemann
`Linacre House, Jordan Hill, Oxford 0X2 8DP
`
`A division of Reed Educational and Professional Publishing Ltd.
`A member of the Reed Elsevier pIc group
`
`British Library Cataloguing in Publication Data
`A catalogue record for this book is available from the British Library
`
`Butterworth-Heinemann ISBN 0 7506 3009 4
`
`All rights reserved. No pan of this publication may be reproduced in any material form (including photo(cid:173)
`copying or storing in any medium by electronic means and whether or not transiently or incidentally to
`some other use of this publication) without the written permission of the copyright holder except in
`accordance with the provisions of the Copyright Designs and Patents Act 1988 or under the terms of a
`license issued by the Copyright Licensing Agency Ltd, 90 Tottenham Court Road, London, England WW
`9HE. Applications for the copyright holder's written permission to reproduce any pan of this publication
`should be addressed to the publishers.
`
`Society of Automotive Engineers, Inc.
`400 Commonwealth Drive, Warrendale, PA 15096-0001
`Phone: (412) 776-4841
`Fax: (412) 776-5760
`
`Library of Congress Cataloging-in-Publication Data
`Nayler, G. H. F.
`Dictionary of mechanical engineering I G.H.F. Nayler. -- 4th ed.
`p. cm.
`ISBN 1-56091-754-7 (hardcover)
`I. Mechanical engineering--Dictionaries. 1. Title.
`TJ9.N28 1996
`621' .03--dc20
`
`95-52297
`CIP
`
`SAE ISBN 1-56091-754-7
`
`Permission to photocopy for internal or personal use, or the internal or personal use of specific
`clients, is granted by SAE for libraries and other users registered with the Copyright Clearance
`Center (CCC), provided that the base fee of $.50 per page is paid directly to CCC, 222 Rose(cid:173)
`wood Dr., Danvers, MA 01923. Special requests should be addressed to the SAE Publications
`Group. 1-56091-754-7/96 $.50.
`
`SAE Order No. R-156
`
`This dictionary 1
`chanical enginee
`term "mechanic,
`tion of, the meal
`transport and me
`making of them,
`limits those tools
`two rare excepti(
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`As regards POWI
`many types of d
`sources and then
`found in other di~
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`are vi tal to the i
`given only minot
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`the choice of cle
`selection of term
`including the fon:
`used terms may n
`entries that will I
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`large field of mec
`are too complica'
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`2
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`mthezinc
`bob. This
`:lock "Big
`In Tune.
`
`rdspring;
`rlewheel;
`f; pallets;
`fpinion.
`
`swinging
`)fthe saw
`
`Jnengine
`the asso-
`
`ardunder
`. osingthe
`
`ms, up to
`lise diffi(cid:173)
`eends of
`~t-metal
`m rollers
`lis fed in
`Iteat 860
`
`endulum
`
`ting of a
`distance
`
`:ciprocal
`
`rals.
`
`peripheral speed The speed of any point on the periphery of a rotating wheel, cut(cid:173)
`ter, etc.
`
`peristaltic pump Apump producing a flow in a fluid within a flexible pipe using a
`series of rollers each of which in tum passes over the same given length of pipe.
`Each roller squeezes the tube progressively, forcing the fluid along the given
`length, but before a roller releases its hold the next one starts its traverse. Thus,
`the fluid is continuously pumped along the pipe.
`With this type of low-pressure pump the fluid is in contact only with the
`interior wall of the flexible tube. This cleanliness feature makes it a popular type
`of pump for medical use, such as in dialysis.
`
`permanent set (a) An extension remaining in a test-piece after the load has been
`removed, the elastic limit of the material having been exceeded. See also stress(cid:173)
`strain relationship and Figure S.26. (b) A permanent deflection of any structure
`after being subjected to a load.
`
`permanent-way crane A gantry crane used for accidents on, and repair of, the
`permanent way of a railway.
`
`perpetual screw Worm .
`
`Persian drill Archimedean drill.
`
`pet cock (priming valve) A small plug-cock for draining condensed steam from
`steam engine cylinders on the starting of the engine, or for testing the water level
`in a boiler.
`
`petrol engine An internal-combustion engine working on the Otto four-stroke or
`the two-stroke cycle using a petrol spray from acarburetor or direct petrol injec(cid:173)
`tion. Ignition of the combustible petrol-air mixture is effected by a sparking
`plug, operated either by coil and battery or by magneto or by a.c. and transistor
`system.
`
`petrol pump (a) A small diaphragm-type pump operated either mechanically from
`the camshaft of the petrol engine, or electrically, for fuel delivery to the carbu(cid:173)
`retor. (b) A pump at a petrol (U.S.: gas) station.
`
`phase Two alternating quantities are said to be "in phase" when their maximum val(cid:173)
`ues occur at the same instant of time.
`phase angle (aJ The angle between two vectors representing two harmoni(cid:173)
`cally varying quantities which have the same frequency, that is, the difference in
`phase measured as an angle. (b) A quantity defining a particular stage of progress
`in a recurring operation.
`phase difference The difference between thephase angles of two harmoni(cid:173)
`cally varying quantities.
`phase reversal A general term for the process of obtaining a signal of iden(cid:173)
`tical waveform but of opposite phase to an original signal.
`phase spectrum The values of the phase angles of the components of a
`vibration, arranged in the order of the frequencies.
`
`277
`
`3