1、Preventive Maintenance3rd EditionPatton04.book Page i Wednesday, February 25, 2004 2:19 PMPatton04.book Page ii Wednesday, February 25, 2004 2:19 PMPreventive MaintenanceJoseph D. Patton, Jr.3rd EditionPatton04.book Page iii Wednesday, February 25, 2004 2:19 PMNoticeThe information presented in this
2、 publication is for the general education of the reader. Because neither the author nor the publisher have any control over the use of the information by the reader, both the author and the pub-lisher disclaim any and all liability of any kind arising out of such use. The reader is expected to exerc
3、ise sound professional judgment in using any of the information presented in a particular application.Additionally, neither the author nor the publisher have investigated or considered the affect of any patents on the ability of the reader to use any of the information in a particular application. T
4、he reader is responsible for reviewing any possible patents that may affect any particular use of the infor-mation presented.Any references to commercial products in the work are cited as examples only. Neither the author nor the publisher endorse any referenced commercial product. Any trademarks or
5、 tradenames referenced belong to the respective owner of the mark or name. Neither the author nor the publisher make any rep-resentation regarding the availability of any referenced commercial product at any time. The manufacturers instructions on use of any commercial product must be followed at al
6、l times, even if in conflict with the information in this pub-lication.Copyright 2004 ISAThe Instrumentation, Systems, and Automation SocietyAll rights reserved. Printed in the United States of America. 10 9 8 7 6 5 4ISBN 1-55617-875-1 No part of this work may be reproduced, stored in a retrieval sy
7、stem, ortransmitted in any form or by any means, electronic, mechanical, photo-copying, recording or otherwise, without the prior written permission ofthe publisher.ISA67 Alexander Drive, P.O. Box 12277Research Triangle Park, NC 27709www.isa.orgLibrary of Congress Cataloging in ProgressPatton04.book
8、 Page iv Wednesday, February 25, 2004 2:19 PMDedicated to my wife, Susan,and children, Jennifer and Joseph III,for their tolerance, understanding, and supportPatton04.book Page v Wednesday, February 25, 2004 2:19 PMPatton04.book Page vi Wednesday, February 25, 2004 2:19 PMviiContentsPreface and Ackn
9、owledgements .xiChapter 1. Major Types of Maintenance 1Improvement MaintenanceCorrective MaintenancePreventive MaintenanceSummaryChapter 2. Advantages and Disadvantages .5AdvantagesManagement ControlOvertimeWork LoadSummaryChapter 3. Designing a PM Program13Failure DataImproving Equipment Reliabilit
10、yImprovement ProcessFailures That Can Be PreventedChapter 4. Economics of PM.29Benefit Versus CostsChapter 5. Nondestructive Inspection43Human SensesThresholdsPatton04.book Page vii Wednesday, February 25, 2004 2:19 PMviii Preventive MaintenanceChapter 6. On-Condition Maintenance.53Chapter 7. Condit
11、ion Monitoring Prediction 59Web-based Condition MonitoringChapter 8. Scheduled Preventive Maintenance .67Chapter 9. Lubrication .71Chapter 10. Calibration79StandardsInspection IntervalsControl RecordsChapter 11. Data and Information 83Organizing DataRangeCumulative DistributionMean, Mode, and Median
12、GraphicsStandard DeviationLog-Normal DistributionConfidence IntervalRisk, Certainty, and UncertaintyMoving AverageWeighted AveragesSamplingChapter 12. Planning and Estimating .97Estimating TimeEstimating Labor CostEstimating MaterialsFeedback from ActualChapter 13. Shutdown Planning .105Critical Pat
13、hCoordinationPatton04.book Page viii Wednesday, February 25, 2004 2:19 PMContents ixChapter 14. Scheduling 109PrioritizingCoordination with ProductionOpportunity PMAssuring CompletionChapter 15. Computerized PM Systems .115Computer Aids for PMWork OrdersFixed Interval SchedulingCondition Monitoring
14、and On-condition MaintenanceComputerized PM Scheduling Resource CoordinationChapter 16. PM Metrics .127Chapter 17. Motivation 133Production/Maintenance CooperationEffectivenessChapter 18. Implementing a New PM Program 137Objectives and GoalsPlansChapter 19. Special Concerns141Parts AvailabilityRepai
15、rable PartsDetailed ProceduresQuality AssuranceAvoiding CallbacksRepairs at PMData GatheringSummaryTrue or False Questions 149Answers 177Selected Readings 181Index.183Patton04.book Page ix Wednesday, February 25, 2004 2:19 PMPatton04.book Page x Wednesday, February 25, 2004 2:19 PMxiPreface and Ackn
16、owledgementsThis book is aimed at high equipment uptime and produc-tivity. Literally everything will fail sometime biological,electrical, electronic, hydraulic, mechanical, nuclear, optical,and especially humans. People spend considerable effort,money, and time trying to fix things faster. The best
17、answer isto avoid the need to fix. No fix is better than fast fix. To quoteBen Franklin, “An ounce of prevention is worth a pound ofcure.” Effective preventive maintenance (PM) is a fundamen-tal support for high operational availability. Preventive maintenance means all actions intended tokeep durab
18、le equipment in good operating equipment andavoid failures. New technology has improved equipmentquality, reliability and dependability by fault-tolerance,redundant components, self-adjustments, and replacement ofhydraulic and mechanical components by more reliable elec-tronic and optical operations
19、. However, many componentscan still wear out, corrode, become punctured, vibrate exces-sively, become overheated by friction or dirt, or even bedamaged by humans. For these problems, a good PM pro-gram will preclude failures, enable improved uptime, andreduce expenses. Success is often a matter of d
20、egree. Costs in terms ofmoney and effort to be invested now must be evaluatedagainst future gains. This means that the time-value of moneyPatton04.book Page xi Wednesday, February 25, 2004 2:19 PMxii Preventive Maintenancemust be considered along with business priorities for short-term versus long-t
21、erm success. Data must be gathered overtime and analyzed to assist with accurate decisions. Theproper balance can be tenuous to achieve minimal downtimeand costs between preventive and corrective maintenance. PM can prevent failures from happening at a bad time,can sense when a failure is about to o
22、ccur and fix it before itcauses damage, and can often preserve capital investmentsby keeping equipment operating for years as well as the dayit was installed. Predictive Maintenance is considered here tobe a branch of Preventive Maintenance.Inept PM, however, can cause problems. Humans are notperfec
23、t. Whenever any equipment is touched, it is exposed topotential damage. Parts costs increase if components arereplaced prematurely. Unless the PM function is presentedpositively, customers may perceive PM activity as, “thatmachine is broken again.” A PM program requires an initialinvestment of time,
24、 materials, people, and money. Payoffcomes later. While there is little question that a good PM pro-gram will have a high return on investment, many people arereluctant to pay now if the return is not immediate. That chal-lenge is particularly predominant is a poor economy wherecompanies want fast r
25、eturn on their expenditures. PM is theepitome of “pay me now, or pay me later.” The PM advantageis that you will pay less now to do planned work when pro-duction is not pushing versus very expensive emergencyrepairs that may be required under disruptive conditions andcause production to halt and los
26、e revenue. Good PM savesmoney over a products life cycle.In addition to economics, emotions play a prominent rolein preventive maintenance. It is a human reality that percep-tions often receive more attention than do facts. A good com-puterized information system is necessary to provide thefacts and
27、 interpretation that guide PM tasks and intervals.PM is a dynamic process. It must support variations in equip-ment, environment, materials, personnel, production sched-ules, use, wear, available time, and financial budgets. Allthese variables impact the how, when, where, and who of PM. Patton04.boo
28、k Page xii Wednesday, February 25, 2004 2:19 PMPreface and Acknowledgements xiiiManagement support is key to good PM. If managementendorses the program, shows interest in activities, and evalu-ates results then PM will be done effectively. The converse istrue of any activity that feels management do
29、es not careabout them. Be proactive and tell management what you aredoing. Explain the need to PM investment to minimize the lifecycle costs and total costs of ownership. Show your financialpeople how the money is being spent so they will supportyour efforts at budget-setting time. Technology provid
30、es thetools for us to use and management provides the direction fortheir use. Both are necessary for success. These ideas areequally applicable to equipment and facility maintenance andfield service in commerce, government, military, and industry.AcknowledgementsThe first edition of Preventive Maint
31、enance was copy-righted in 1983. It was written at the request of several agri-cultural and mechanical colleges that needed a text book forcourses in mechanical technology and maintenance. Itreceived excellent reception and was used by many colleges,including the US Naval Academy, and in professiona
32、l training.Translations have been done in languages including Arabicand French Canadian. The first edition of Preventive Mainte-nance benefited from Patton Consultants associates includ-ing Herbert C. Feldman, Lawrence S. Beale, Michael A.Felluca, and Mary Ann Bianchi. That edition was reviewed byAm
33、by T. Uphold and personnel of Polystart Limited, and byJoseph Zdun and his national Service Staff of Leeds &Northrup. The second edition was copyrighted in 1995. It washelped by further input from Herb Feldman and Molly Forest.Participants in workshops on “How to Design and Implementa Preventive Mai
34、ntenance Program” and “Product Reliability,Availability, Quality, and Serviceability” may recognize theirenhancements. Susan O. Patton suggested changes to botheditions that made the material easier to comprehend. SusanPatton04.book Page xiii Wednesday, February 25, 2004 2:19 PMxiv Preventive Mainte
35、nancehas also tolerated the considerable time required to writewhat is always “the last” book. This third edition is stimulated by both the simultaneousneed to print more books and to update the material, espe-cially about computerized support systems. The COMMSCOMputerized Management System origina
36、lly designed byPatton Consultants, Inc. and Service InfoSystems, Inc.(another Patton company) was sold and went out of businessalong with its new owner. Roy J. Steele of Patton Consultants,Inc. provided suggestions that have improved this material.Training courses in Preventive Maintenance presented
37、 for LifeCycle Engineering and other organizations have alwaysadded clarification and new ideas that are included in thisthird edition of Preventive Maintenance.Patton04.book Page xiv Wednesday, February 25, 2004 2:19 PM1CHAPTER1Major Types of MaintenanceThere are three main types of maintenance and
38、 three majordivisions of preventive maintenance, as illustrated in Figure1-1.IMPROVEMENT MAINTENANCEPicture these divisions as the five fingers on your hand.Improvement maintenance efforts to reduce or eliminateentirely the need for maintenance are like the thumb, the firstand most valuable digit. W
39、e are often so involved in maintain-ing that we forget to plan ahead and eliminate the need at itsFigure 1-1Structure of Maintenance.Patton04.book Page 1 Wednesday, February 25, 2004 2:19 PM2 Preventive Maintenancesource. Reliability engineering efforts should emphasize elim-ination of failures that
40、 require maintenance. This is an oppor-tunity to preact instead of react.For example, many equipment failures occur at inboardbearings that are located in dark, dirty inaccessible loca-tions. The oiler does not lubricate those bearings as often ashe lubricates those that are easy to reach. That is a
41、 naturaltendency. One can consider reducing the need for lubricationby using permanently lubricated, long-life bearings. If that isnot practical, at least an automatic oiler could be installed. Amajor selling point of new automobiles is the elimination ofignition points that require replacement and
42、adjustment,introduction of self-adjusting brake shoes and clutches, andextension of oil change intervals.CORRECTIVE MAINTENANCEThe little finger in our analogy to a human hand repre-sents corrective (emergency, repair, remedial, unscheduled).At present, most maintenance is corrective. Repairs willal
43、ways be needed. Better improvement maintenance and pre-ventive maintenance, however, can reduce the need foremergency corrections. A shaft that is obviously broken intopieces is relatively easy to maintain because little humandecision is involved. Troubleshooting and diagnostic faultdetection and is
44、olation are major time consumers in mainte-nance. When the problem is obvious, it can usually be cor-rected easily. Intermittent failures and hidden defects aremore time-consuming, but with diagnostics the causes can beisolated and then corrected. From a preventive maintenanceperspective, the proble
45、ms and causes that result in failuresprovide the targets for elimination by PM. The challenge is todetect incipient problems before they lead to total failuresand to correct the defects at the lowest possible cost. Thatleads us to the middle three fingers-the branches of preven-tive maintenance.Patt
46、on04.book Page 2 Wednesday, February 25, 2004 2:19 PMMajor Types of Maintenance 3PREVENTIVE MAINTENANCEOn-ConditionOn-condition maintenance is done when the equipmentneeds it. Inspection through human senses or instrumenta-tion is necessary, with thresholds established to indicatewhen potential prob
47、lems start. Human decisions arerequired to establish those standards in advance so thatinspection or automatic detection can determine when thethreshold limit has been exceeded. Obviously, a relativelyslow deterioration before failure is detectable by conditionmonitoring, whereas rapid, catastrophic
48、 modes of failuremay not be detected. Great advances in electronics and sen-sor technology are being made.Also needed is a change in human thought process.Inspection and monitoring should disassemble equipmentonly when a problem is detected. The following are generalrules for on-condition maintenanc
49、e: Inspect critical components. Regard safety as paramount. Repair defects. If it works, dont fix it.Condition MonitorStatistics and probability theory are the basis for condi-tion monitor maintenance. Trend detection through dataanalysis often rewards the analyst with insight into thecauses of failure and preventive actions that will help avoidfuture failures. For example, stadium lights burn out within anarrow range of time. If 10 percent of the lights are burnedout, it may be accurately assumed that the rest will fail soonand should, most effectively, be re
