1、AGMA INFORMATION SHEET(This Information Sheet is NOT an AGMA Standard)AGMAISO14179-1AGMA ISO 14179-1(ISO/TR 14179-1:2001(Mod)AMERICAN GEAR MANUFACTURERS ASSOCIATIONGear Reducers - Thermal Capacity Basedon ISO/TR 14179-1iiGear Reducers - Thermal Capacity Based on ISO/TR 14179-1AGMA ISO 14179-1ISO/TR
2、14179-1:2001 (Mod)CAUTION NOTICE: AGMA technical publications are subject to constant improvement,revision, or withdrawal as dictated by experience. Any person who refers to any AGMAtechnicalpublicationshouldbesurethatthepublicationisthelatestavailablefromtheAs-sociation on the subject matter.Tables
3、orotherself-supportingsectionsmaybereferenced. Citationsshouldread: SeeAGMA ISO 14179-1, Gear Reducers - Thermal Capacity Based on ISO/TR 14179-1,published by the American Gear Manufacturers Association, 500 Montgomery Street,Suite 350, Alexandria, Virginia 22314, http:/www.agma.org.Approved March 4
4、, 2004ABSTRACTThis information sheet utilizes an analytical heat balance model to provide a means of calculating the thermaltransmittable power of a single- or multiple-stage gear drive lubricated with mineral oil. The calculation isbasedonstandardconditionsof25Cmaximumambienttemperatureand95Cmaximu
5、moilsumptempera-ture in a large indoor space, but provides modifiers for other conditions.Published byAmerican Gear Manufacturers Association500 Montgomery Street, Suite 350201, Alexandria, Virginia 22314Copyright 2004 by American Gear Manufacturers AssociationAll rights reserved.No part of this pub
6、lication may be reproduced in any form, in an electronicretrieval system or otherwise, without prior written permission of the publisher.Printed in the United States of AmericaISBN: 1-55589-821-1AmericanGearManufacturersAssociationAGMA ISO 141479-1AMERICAN GEAR MANUFACTURERS ASSOCIATIONiiiContentsPa
7、geForeword iv.1 Scope 1.2 Symbols and units, term and definitions 13 Rating criteria 34 Service conditions 45 Methods for determining the thermal rating 4.6 Method A - Test 47 Method B - Calculations for determining the thermal power rating, PT68 Modifications for non-standard operating conditions 1
8、5AnnexesA Bevel gear mesh and gear windage power losses 17B Worm gear mesh power losses 19C Illustrative example 21Bibliography 26.Figures1 Determination of thermal rating by test 5.2 Graphical representation of calculation of thermal rating 73 Tapered roller bearing load equations 10.4 Seal frictio
9、n torque 12.5 Bearing dip 13.Tables1 Symbols and units 12 Factors for calculating M183 Exponents for calculation of M19.4Factorf2for cylindrical roller bearings 95 Bearing dip factor, f014.6Factorsf3and f414.7 Heat transfer coefficient, k, for gear drives with fan cooling 158 Ambient temperature mod
10、ifier, Bref16.9 Ambient air velocity modifier, BV16.10 Altitude modifier, BA1611 Maximum allowable oil sump temperature modifier, BT1612 Operation time modifier, BD16.AGMA ISO 141479-1 AMERICAN GEAR MANUFACTURERS ASSOCIATIONivForewordThe foreword, footnotes and annexes, if any, in this document are
11、provided forinformational purposes only and are not to be construed as a part of AGMA ISO 14179-1,Gear Reducers - Thermal Capacity based on ISO/TR 14179-1.This thermal rating method was the American proposal to ISO/TR 14179. It utilizes ananalytical heat balance model to calculate the thermal transm
12、ittable power for a single ormultiple stage gear drive lubricated with mineral oil. Many of the factors in the analyticalmodelcantracetheirrootstopublishedworksofvariousauthors. TheprocedureisbasedonthecalculationmethodpresentedinAGMATechnicalPaper96FTM9byA.E.Phillips1.The bearing losses are calcula
13、ted from catalogue information supplied by bearingmanufacturers,whichinturncanbetracedtotheworkofPalmgren. ThegearwindageandchurninglossformulationsoriginallyappearedinworkpresentedbyDudley,andhavebeenmodified to account for the effects of changes in lubricant viscosity and amount of gearsubmergence
14、. The gear load losses are derived from the early investigators of rollingandsliding friction who approximated gear tooth action by means of disk testers. Thecoefficients in the load loss equation were then developed from a multiple parameterregressionanalysisofexperimentaldatafromalargepopulationof
15、testsintypicalindustrialgeardrives. Thesegeardrivesweresubjectedtotestingwhichvariedoperatingconditionsover a wide range. Operating condition parameters in the test matrix included speed,power, direction of rotation and amount of lubricant. The formulation has been verified bycrosscheckingpredictedr
16、esultstoexperimentaldataforvariousgeardriveconfigurationsfrom several manufacturers.AGMAISO14179-1isnotidenticaltoISO/TR14179-1:2001,Gears - Thermalcapacity -Part1: Ratinggeardriveswiththermalequilibriumat95Csumptemperature. Differencesin this information sheet include:- In table 2, the second equat
17、ion for P1for spherical roller bearings was changed tocorrectly indicate the condition (Fr/Fa) Y2;- Text and a figure were added to clause 6 to assist in illustrating Method A testing;- Text and a figure were added to 7.1 to assist in illustrating the thermal calculationprocedure;- Figures A.1 and A
18、.2 were revised to accurately reflect dimensions shown;.- An annex was added to provide example calculations.ThefirstdraftofAGMAISO14179-1wasmadeinDecember,2002. ItwasapprovedbytheAGMA membership in March, 2004Suggestionsforimprovementofthisstandardwillbewelcome. TheyshouldbesenttotheAmericanGearMan
19、ufacturersAssociation,500MontgomeryStreet,Suite350,Alexandria,Virginia 22314.AGMA ISO 141479-1AMERICAN GEAR MANUFACTURERS ASSOCIATIONvPERSONNEL of the AGMA Enclosed Drives for Industrial Applications CommitteeChairman: Richard W. Holzman Innovative Gearing Solutions, LLC.Vice Chairman: Gary A. DeLan
20、ge Hansen Transmissions.ACTIVE MEMBERSS.E. Bond, Jr. Ace Engineering Ltd.D. Borden D.L. Borden, IncC. Burriss Amarillo Gear Company.R.L. Cragg Steward Machine Company, Inc.M. Konruff Falk Corporation.T. Praneis Cotta Transmission Company, LLC.M. Shows Lufkin Industries, IncR.G. Smith Philadelphia Ge
21、ar CorporationT. Youngblood Brevini USA, IncASSOCIATE MEMBERSJ.F. Alison, III Steward Machine Company, Inc.J. Anno Xtek, IncM. Arledge Griffin Gear, Inc.K.O. Beckman Lufkin Industries, IncL. Brown Gear Products, Inc.C. Carrigan EPT Gearing, Morse, Browning, USEMJ. Cartellone Horsburgh - ambient air
22、temperature of 25 C;- ambientairvelocityoflessthanorequalto1.4m/s in a large indoor space;- air density at sea level;- continuous operation.Modifyingfactorsfordeviationfromthesecriteriaaregiveninclause8.4 Service conditions4.1 Intermittent serviceForintermittentservice,theinputpowermayexceedthe manu
23、facturers thermal power rating, providedthe oil sump temperature does not exceed 95 C.Seeclause8.4.2 Adverse conditionsTheabilityofageardrivetooperatewithinitsthermalpower rating may be reduced when adverse condi-tionsexist. Someexamplesofadverseenvironmen-tal conditions are:- an enclosed space;- bu
24、ild-up of material that may cover the geardrive and reduce heat dissipation;- high ambient temperature, such as boiler orturbinerooms,orinconjunctionwithhotprocess-ing equipment;- high altitudes;- presence of solar energy or radiant heat.4.3 Favorable conditionsThe thermal power rating may be enhanc
25、ed whenoperating conditions include increased air move-ment or a low ambient temperature.4.4 Auxiliary coolingAuxiliary cooling should be used when the thermalratingisinsufficientforoperatingconditions. Oilcanbe cooled by a number of means, such as:- fan cooling, in which case the fan shall main-tai
26、n the fan cooled thermal power rating;- heat exchanger, which when used shall becapable of absorbing generated heat that cannotbedissipatedbythegeardrivebyconvectionandradiation.5 Methods for determining the thermalratingThermal rating may be determined by one of twomethods: method A, testing, or me
27、thod B,calculation.MethodA,atestoffullscalegeardrivesatoperatingconditions,isthemostaccuratemeansofestablish-ingthethermalratingofthegeardrive. Seeclause6.WhenmethodBisused,thethermalratingofageardrive can be calculated using the heat balanceequation, which equates heat generated with heatdissipated
28、. See clause 7 (the means of calculatingheat generation is discussed in 7.2 to 7.11, and forheat dissipation, in 7.12).6 Method A - TestTesting a specific gear drive at its design operatingconditionsisthemostreliablemeansofestablishingthethermalrating. Thermaltestinginvolvesmeasur-ingthesteady-state
29、bulkoilsumptemperatureofthegear drive operating at its rated speed at no-loadand at least one or two increments of load. Prefer-ably,onetestshouldbeat95C sumptemperature.Whileno-loadtestingcannotyieldathermalrating,itmay be used to approximate the heat transfercoefficient for comparison purposes, pr
30、ovided thepower required to operate the drive at no-load ismeasured.The following are some guidelines for acceptablethermal testing.AGMA ISO 14179-1AMERICAN GEAR MANUFACTURERS ASSOCIATION5- ambientairtemperatureandvelocitymustbestabilized and measured for the duration of thetest;- time required for
31、the gear drive to reach asteady-state sump temperature depends uponthe drive size and the type of cooling;- steady-state conditions can be approxi-mated when the change in oil sump temperatureis less than or equal to 1 C/h.Theoiltemperatureinthesumpat various locationscanvarybyasmuchas15 C. The loca
32、tion of thetemperature measurement should represent thebulk oil temperature. Outer surface temperaturescan vary substantially from the sump temperature.The opposite direction of rotation can create adifferent sump temperature.During thermal testing, the housing outer surfacetemperature can be survey
33、ed if detailed analysis ofthe heat transfer coefficient and effective housingsurfaceareaisdesired. Also,withfancooling,theairvelocitydistributionoverthehousingsurfacecanbemeasured.Using thermal test results to determine the experi-mental thermal rating is illustrated in figure 1. Tominimizetheeffect
34、ofsmallvariations( 3C)intheambient air temperature, the measured steady-stateoilsumptemperaturerise(sumptemperature-ambient air temperature) is plotted versus the inputpower. Figure 1 illustrates the thermal ratingdetermined by test to be at the intersection of themaximum allowable oil sump temperat
35、ure rise andthecurvefittothetestdata. Thermaltestingcanalsobe used to verify a calculated thermal rating, or toimprovethecorrelationandempiricalfactorsusedinthe thermal rating calculation.Maximumallowable TSSCurve fit totest dataTSS,CPA,kW= Test dataPTDeterminedby testTSS= steady-state oil sump temp
36、erature rise = TSS- TA, CTSS= steady-state sump temperature, CTA= ambient air temperature, CPA= input power, kWPT= thermal rating, kW1. Plot test data (TSSversus PA).2. Establish curve fit to test data.3. Establish maximum allowable TSSbased on maximum allowable oil sumptemperature and average ambie
37、nt air temperature from test data.4. The intersection of the maximum allowable TSSand the test data curve fitidentifies the thermal rating PT.Figure 1 - Determination of thermal rating by testAGMA ISO 14179-1 AMERICAN GEAR MANUFACTURERS ASSOCIATION67 Method B - Calculations for determiningthe therma
38、l power rating, PT7.1 BasisThe calculation of thermal rating, PT, is an iterativeprocess, due to the load dependency of the coeffi-cient of friction for the gear mesh and the bearingpower loss.The basis of the thermal rating is when the losses,PV,atPAare equal to the heat dissipation, PQ,ofthegear d
39、rive.PQ= PV(1)Whenthis is satisfiedunder theconditions ofclause3, PAis defined as PT.The heat generation in a gear drive, PV, comes fromboth load dependent, PL, and non-load dependentlosses, PN.PV= PL+ PN(2)PLis a function of the input power, PA.PL= fPA (3)Using equation 1 and substituting terms, we
40、 canwrite the basic heat balance equation as follows:PQ PN fPA= 0(4)To determine the basic thermal rating, PT,varyPAuntil equation 4 is satisfied. This can be done byrecalculating the load dependent losses, PL,atdifferent input powers, PA. With appropriate heatdissipation and heat generation terms i
41、ncluded inequation4,valuesofPAaretrieduntilaheatbalanceisobtained(iterativesolution)andthesolutionvalueof PAbecomes the thermal rating PT. A graphicalrepresentation of this procedure is illustrated infigure 2 where calculated PVand PQare plottedversus oil sump temperature rise. Calculated PVcurves a
42、re illustrated for various iterative values ofPA. The thermal rating is defined by the thermalequilibrium point where PV= PQat the maximumallowable oil sump temperature rise, with the corre-sponding value of PAequal to PT.If PQis less than or equal to PNat no-load, the geardrive does not have any th
43、ermal capacity. ThedesignmustbechangedtoincreasePQ,orauxiliarycooling methods must be used.When equation 4 is satisfied, the overall unitefficiency, ,is calculated as follows: = 100 PL+ PNPA 100(5)The thermal rating of the gear drive is as follows:PT=PQ1 100(6)The following thermal model has been es
44、tablishedusingempiricalfactors. Itisbasedontheexperienceofseveralgearmanufacturers. Themodelhasbeenvalidated by extensive testing of concentric-shaft,base-mounted reducers with shafts mounted in ahorizontal orientation. Limited testing of someparallel shaft gear units has also been performed inorder
45、 to spot check the adequacy (validity) of themodel. Values of some variables such as arrange-ment constant, heat transfer coefficient and coeffi-cient of friction may not adequately address otherenclosed drive configurations and operating condi-tions. Other configurations or conditions maynecessitat
46、emodificationsoftheparticularvariables.Changing any variable requires care and testing toensure that the principles of the heat balanceformulation are not violated.7.2 Heat generationHeatgeneratedinageardrivecomesfrombothloaddependent,PL,andnon-loaddependentlosses,PN.Loaddependentlossesarecomprisedo
47、fthesumofall individual bearing losses, PB, and the sum of allindividual gear mesh losses, PM:PL=PB+PM(7)Non-loaddependentlossesconsistofthesumofallindividualoilseallosses,PS,thesumofallindividualinternal windage and oil churning losses for thegears and bearings, PWand PWB, respectively, andthe sum
48、of all individual oil pump powers, PP,consumed.PN=PS+PW+PWB+PP(8)Theselossesmustbesummedforeachoccurrencein the gear drive.AGMA ISO 14179-1AMERICAN GEAR MANUFACTURERS ASSOCIATION7Thermal equilibriumpoint where PV= PQat maximumallowable TSSCalculated PVforsolution value ofPA= PTCalculated PVforiterat
49、ive values of PAPV,kWPQ,kWCalculatedPQMaximumallowableTSSTSS, CPV= heat generation, kWPQ= heat dissipation, kWTSS= steady-state oil sump temperature rise = TSS- TA, CTSS= steady-state oil sump temperature, CTA= ambient air temperature, CPA= input power, kWPT= thermal rating, kW1. Establish maximum allowable TSSbased on maximum allowable oil sump tempera-ture and rating ambient air temperature.2. Establish math model for calculation of PVand PQversus TSS.3. By it
