ANSI AGMA 6022-C93-1993 Design Manual for Cylindrical Wormgearing.pdf

1、ANSI/AGMA 6022-C93Revision of AGMA 341.02Reaffirmed May 2014American National StandardDesign Manual for CylindricalWormgearingANSI/AGMA6022-C93iiDesign Manual for Cylindrical WormgearingAGMA 6022-C93 (Revision and Redesignation of AGMA 341.02)Approval of an American National Standard requires verifi

2、cation by ANSI that the requirements for dueprocess, consensus, and other criteria for approval have been met by the standards developer.Consensus is established when, in the judgment of the ANSI Board of Standards Review, substantialagreement has been reached by directly and materially affected int

3、erests. Substantial agreement meansmuch more than a simple majority, but not necessarily unanimity. Consensus requires that all views andobjections be considered, and that a concerted effort be made toward their resolution.The use of American National Standards is completely voluntary; their existen

4、ce does not in any respectprecludeanyone,whetherhehasapprovedthestandardsornot,frommanufacturing,marketing,purchasing,or using products, processes, or procedures not conforming to the standards.The American National Standards Institute does not develop standards and will in no circumstances give ani

5、nterpretation of any American National Standard. Moreover, no person shall have the right or authority toissue an interpretation of an American National Standard in the name of the American National StandardsInstitute. Requests for interpretation of this standard should be addressed to the American

6、GearManufacturers Association.CAUTION NOTICE: AGMA standards are subject to constant improvement, revision or withdrawal asdictatedbyexperience. AnypersonwhoreferstoanyAGMATechnicalPublicationshoulddeterminethatitisthe latest information available from the Association on the subject.Tables or other

7、self-supporting sections may be quoted or extracted in their entirety. Credit line should read:Extracted from AGMA 6022-C93, Design Manual for Cylindrical Wormgearing, with the permission of thepublisher, American Gear Manufacturers Association, 1500 King Street, Alexandria, Virginia 22314.Approved

8、December 16, 1993American National Standards Institute, Inc.ABSTRACT:ThisDesignManualprovidesinformationpertainingtoselectionofgeometricparameterswhichwillconstitutegood design of fine and coarse pitch cylindrical wormgearing. The power rating for fine and coarse pitchwormgearing is not included in

9、this design manual but can be found in AGMA 6034, Practice for EnclosedCylindrical Wormgear Speed Reducers and Gearmotors.Copyright , 1993 by American Gear Manufacturers AssociationPublished byAmerican Gear Manufacturers Association1500 King Street, Suite 201, Alexandria, Virginia 22314ISBN: 1-55589

10、-618-9ANSI/AGMA 6022-C93iiiContents PageForeword vi.1 Scope 1.1.1 Uses of wormgearing 1.1.2 Intended use 1.2 Symbols, terms and definitions 1.3 General design considerations 3.3.1 Characteristics of wormgearing 3.3.2 Loading 4.3.3 Ratios 4.3.4 Conjugate action 5.3.5 Thread profile of worm 53.6 Accur

11、acy requirements 84 Design procedure 104.1 Number of teeth in the wormgear 104.2 Number of threads in the worm 104.3 Worm pitch diameter 10.4.4 Wormgear pitch diameter 10.4.5 Worm axial pitch 10.4.6 Worm lead 114.7 Lead angle of the worm 11.4.8 Pressure angle 114.9 Customary thread and tooth proport

12、ions 115 Modified tooth proportions 145.1 High contact ratio designs 145.2 Stub tooth designs 15.5.3 Recess and approach action 155.4 Design for additional or full recess action 155.5 Alternative design for additional or full recess action gearing 166 Contact patterns 166.1 Initial contact for power

13、 drive wormgearing 176.2 Unacceptable initial contact 17.6.3 Mounting and assembly problems and their effects on initial contact patterns 17.6.4 Other causes of variations in initial contact patterns 186.5 Wormgear contact under load 19.6.6 Special initial wormgear contact 19.7 Run-in procedures 197

14、.1 Definition of run-in 19.7.2 Results of run-in 207.3 Initial running at full load 207.4 Initial friction at the mesh 20.7.5 Recommended run-in period 207.6 Wormgear pitting 20ANSI/AGMA 6022-C93ivContents (cont) Page8 Rating and efficiency 20.9 Wormgear blank design 209.1 Typical wormgear blank con

15、figuration 21.9.2 Wormgear web configuration 219.3 Wormgear hub design 2110 Worm manufacturing practices 2110.1 Worm thread milling 2110.2 Worm thread milling with multiple milling cutters 2210.3 Worm thread hobbing 2210.4 Worm thread generating with a shaper cutter 2210.5 Worm thread rolling 2210.6

16、 Worm thread grinding 2211 Wormgear manufacturing practices 2211.1 Wormgear hobs 22.11.2 Wormgear hob design 2311.3 Wormgear flyhobbing 2312 Materials and heat treatment 2312.1 Worm materials 24.12.2 Wormgear materials 25.13 Lubrication 2513.1 Regimes of lubrication 2513.2 Mineral oils 25.13.3 Synth

17、etic oils 2513.4 Splash lubrication 2513.5 Forced feed lubrication 26.14 Analysis of gearing forces, worm bending stress, and deflection 26.14.1 Tangential, separating, and thrust forces 2714.2 Worm bearing reactions 2714.3 Worm bending stress 28.14.4 Allowable worm bending stress 2814.5 Worm deflec

18、tion 28.15 Assembly procedures 2915.1 The housing 2915.2 Position tolerance 29.15.3 Contact pattern check 2915.4 Backlash check 30.15.5 End play check 30Tables1 Symbols used in equations 1.2 Suggested minimum number of wormgear teeth for customary designs 103 Suggested minimum number of wormgear tee

19、th for modified designs 16.ANSI/AGMA 6022-C93vContents (cont) PageFigures1 Lines of contact on wormgear teeth 3.2 Relative radii of curvature 43 Number of teeth in contact 4.4 Rack profiles of worms 55 Form ZA 66 Form ZN 67 Form ZK 78 Form ZI 7.9 Profile measurement of form ZI 8.10 Tooth spacing acc

20、uracy changes - 30 tooth wormgear 9.11 Tooth spacing accuracy changes - 29 tooth wormgear 9.12 Variation of lead angle 1113 Normal chordal thread thickness of worm 12.14 Worm face width 1315 Wormgear face width 14.16 Wormgear basic dimensions - customary proportions 14.17 Approach and recess action

21、- customary proportions 15.18 Approach and recess action - modified proportions 17.19 Initial no-load wormgear contact 18.20 Initial no-load wormgear contact variations due to wormgear tooth spacing errorseven ratio (40/2 = 20 ratio) 1921 Special initial no-load wormgear contact 1922 Typical wormgea

22、r blank configuration minimum rim thickness 2123 Generation of wormgear teeth 22.24 Hobbing of wormgears 24.25 Flytool hobbing of wormgears 24.26 Worm and wormgear forces - RH thread 2727 Worm bearing reactions 2828 Equivalent beam for worm 28AnnexesA Formulas for worm thread profiles 31B Sources of

23、 formulas used for determining worm thread profiles 33.C Sources of information concerning hob design 34.D Worm thread profiles - axial sections 35.ANSI/AGMA 6022-C93viFOREWORDTheforeword,footnotes,andannexes,ifany,areprovidedforinformationalpurposesonlyandshouldnotbeconstruedaspartofAGMA6022-C93,De

24、signManualforCylindricalWormgearing(formerly341.02,Designof General Industrial Coarse-Pitch Cylindrical Wormgearing).The standard provides a broad range of design parameters for fine and coarse pitch cylindricalwormgearingwhichwouldconstitutefeasibledesign,withinwhichthedesignermaysearchforabetterde

25、sign.Thegreatestpossible latitude for design has been sought.The earlier standard AGMA 341.01, was approved by the AGMA membership in June 1955, and AGMA341.02 was approved by the membership in December 1964 and reaffirmed in May 1970.Standard AGMA 374.01, Design for Fine-Pitch Wormgearing is being

26、withdrawn.Data contained herein represents a consensus from among engineering representatives of membercompanies of AGMA and other interested parties.AGMAStandardsaresubjecttoconstantimprovement,revision,orwithdrawalasdictatedbyexperience.Anyperson who refers to AGMA technical publications should sa

27、tisfy himself that he has the latest informationavailable from the Association on the subject matter.Tables or other self-supporting sections may be quoted or extracted in their entirety. Credit should readExtracted from AGMA 6022-C93, Design Manual for Cylindrical Wormgearing, with permission of th

28、epublisher, the American Gear Manufacturers Association, 1500 King Street, Suite 201, Alexandria, Virginia22314.ANSI/AGMA 6022-C93viiPERSONNEL of the AGMA Cylindrical Wormgearing CommitteeChairman: Joseph R. DeMarais Bison Gear and EngineeringEditor: Richard J. Will IMO-Delroyd.ACTIVE MEMBERSGregory

29、 Georgalas Dorr-Oliver IncWerner H. Heller Peerless-Winsmith, Inc.Vadim Kin Mforexample,a1inch(25.4mm)centerdistance20:1 design could be made as a 20/1 design but a 36inch (914.4 mm) center distance wormgear wouldbe more likely designed with 59 or 60 teeth in thewormgear and 3-threads in the worm fo

30、r a 59/3 =19-2/3 or 60/3 = 20 ratio.41/2 = 20-1/220 Pressure Angle 20 Pressure Angle80/4 = 20-0/4123123Figure 3 - Number of teeth in contactANSI/AGMA 6022-C935In the design or selection of ratios requiringmultiplethread worms, there are two tooth combinationsystems that can be used. One is the even

31、numbersystem where the number of teeth in the wormgearcan be evenly divided by the number of threads inthe worm, for example (40/2 = 20:1). The huntingtooth ratio system uses a combination of wormgearteeth and worm threads where the number of teethin the wormgear is not evenly divisible by thethread

32、s of the worm, for example (39/2 = 19.5:1).Over the years, there has been a difference ofopinion of the benefit of one system over the other.Utilizing current state of the art manufacturingequipment, tools, and technology has resulted ineither of the two systems performing suitably invirtually all t

33、ypes of applications.Indesignsrequiringprecision,motiontransmission,or designs that are extremely cost sensitive, furtherinvestigation of the hunting tooth wormgear systemversus even number wormgear system may berequired.3.4 Conjugate actionFor gears, two surfaces are conjugate if onegenerates the o

34、ther when both are rotated at aspecified relative uniform motion. In wormgearing,the worm, when rotated, results in a series of rackprofiles being advanced along its axis as shown infigure 4.As can be seen in figure 4, the center section hasidentical pressure angles on both flanks but off-center sec

35、tions are not symmetrical. In any case,the hob that generates the wormgear teeth has anidentical series of rack sections that generate thewormgear teeth, so that conjugate action in awormgear is essentially the same as conjugateaction between a rack and pinion. The particularshape of the rack profil

36、es from tip to root does notaffect the conjugacy as long as the worm and thewormgear hob have the same profile type andpressure angle (see figure 4).3.5 Thread profile of wormThe thread profile or shape of the thread flanks canbe described by the method used for the manufac-ture of the worm. No limi

37、tation is placed on themethod used except that the hob or tooling used toproduce the wormgear should have substantiallythe same profile as the worm so that the matingwormgear has proper contact with the worm, andthe gear pair provides uniform transmission ofmotion. Sometipandrootreliefforthewormgear

38、aswell as oversize and short lead for the hob isfrequently used to provide “crowning” of the worm-gear teeth to assure the uniform transmission ofmotion and prevent excessive noise, dynamicloads, and vibration. Because of the number ofdifferent thread profiles in use, it is generallydesirablethatthe

39、wormandwormgearbemanufac-turedbythesamesuppliertoassureproper mating.While successful applicationsarepossiblewithanyof the common thread forms in use, some profilesare more suited to particular applications thanothers depending on speed, ratio and degree ofaccuracy required.BACBACSection A-A Section

40、 B-BSection C-CFigure 4 - Rack profiles of wormsANSI/AGMA 6022-C9363.5.1 Straight sided axial profile - Form ZAThis profile can be produced with a straight sidedlathe tool placed on the axial plane as shown infigure 5.Ifarotarymillingcutteroragrindingwheelisusedtoproduce a ZA profile worm thread, su

41、ch a cutter orgrindingwheelwouldrequireconvexprofiledcuttingedges. Profile variations of the worm are easilychecked for this FormZA profilesince itis astraightline in the axial plane. The central section of themating wormgear is theoretically an involute shapeand its profile variations can be checke

42、d with aninvolute checker.Top ViewSide ViewFigure 5 - Form ZA3.5.2 Straight sided normal profile - Form ZNThis profile is produced with a straight sided lathetoolwithitscuttingfacetiltedtotheleadangleofthethread at its mean diameter as shown in figure 6.As with Form ZA profiles, a suitably convex pr

43、ofiledrotary or conical milling cutter or grinding wheelwould have to be used to produce Form ZN profile.mTop ViewSide Viewm= lead angle at worm mean diameterFigure 6 - Form ZN3.5.3 Profileresultingfromstraightsidedrotarymilling cutter or grinding wheel - Form ZKThis profile is a convex profile in t

44、he axial andnormal planes of the worm resulting from the use ofa straight sided milling cutter or grinding wheel withits axis tilted to the lead angle of the thread at itsmean diameter. The center plane of the cutter orwheel must intersect the axis of the worm at thecenterline of the thread space. T

45、he shape of thethreadflankproducedisdependentonthediameterof the cutter or grinding wheeldue to thegeneratingaction of the tool. See figure 7.Profile variations of Form ZK profiles on finishedwormsmustbemeasuredrelativetoaconvexcurvewithavaryingpressureangle,toptobottom, andasa result are not as eas

46、ily determined. The mainadvantageofthisformistheeaseofsharpeningthecutter or dressing the grinding wheel.ANSI/AGMA 6022-C937Top ViewSide Viewmm= lead angle at wormmean diameterFigure 7 - Form ZK3.5.4 Involute helicoid - Form ZIThis thread profile can be produced one flank at atime by a flat sided cu

47、tter or grinding wheel whoseaxisistiltedtotheleadangleofthewormatitsmeandiameter and also inclined to the desired pressureangle of the worm at its mean diameter as shown infigure 8.The profile produced by this method is a convexcurve in both the normal and axial planes of theworm and is independent

48、of the diameter of the cut-ter or grinding wheel. The sharpening of the cutterordressingofthegrindingwheelis easilycontrolledin this method because it is a flat surface perpen-diculartothecutteror wheelaxis. Desired profileofthe resulting worm is a straight line at the off centersection at the base

49、radiusand baselead angle(seefigure9).Profilevariationrelativetothisstraightlineis easily inspectedif properinspection equipmentisavailable (see figure 9).Ifbothflanksofaninvolutewormaretobegroundatthe same time, the rotary cutter or grinding wheelcan be tilted to the lead angle at the worm meandiameter and not inclined to the normal pressureangle. However, the cutter or wheel must beproperly vee shaped with concave profiled flankforming surfaces in order to obtain the desiredinvolute shape. Sharpening the cutter or dressingthe grinding wheel is m