92

November/December 2000 Gear Technology

Embed Size (px)

Citation preview

  • At Gle',ason' C,utting foo,ls,

    WE'RE TAKING PLATINGPlating Bath

    Gleason 'Cutting Too'is t- C IiI)jLove- p,-rt, 11.

  • Introducing our grinding wheel plating facilityjone of 'the' 'world's most adllan'ced.Here's the alternative ourceyou've always wanted foryour CBN and diamondgrinding wheels.

    With the addition of our newplating facility, we now havethe capability to produce afun line of high-precisionbevel. and cylindricalelectro-plated metal-bonded,single-layer, replatable eBNand diamond grindingwheels for use with anymodem CNC profilegrinding, gear honing, orgear grinding machine ..

    Higher stock removal rates, lowercost-per workpiece, longerwheel life, and more consistentqualityareall easier toachieve.

    We also offer fast tum-aroundand short delivery times from astock wheel blank inventory ina variety of configurations andize _. Get quick tum-around

    on stripping and replatingservices too.

    CtRCUE 1110

    Q.:ra.und OMr'~ ~I"": '1ft.UJJ:~'I-- 'I':.gel!'PrcIh--lqM,c,!lNG!ound ......

    - ~....... ,I!MI---, --CMIrIr i!IIlIiIn:II - It..""- 1IiIiII... 20tr~__ ..a0Cl0l" ~_ 21MW~"dii lItMIik IIIDCI"[22'.wv~~n --;.=:n~o~_:l~:-~J::~__-l~!!~~::~~~t:~

    Gileason IC'utt;ing 'ToolsCORPORATI:ON

    1351 Windsor Roadloves Park, Il61111 USAWeb Site: www.gleasoo.com

    Phone:B 15-877,8900'Fax: 81~77'()264

    E-Mail: [email protected]

    http://www.gleasoo.commailto:[email protected]

  • CIACLJE 132

  • Til Journal of Gear ianufacturing '--- _

    Design Against Tooth Inter,iof IFatigue fracture,A study o(a ccmmon, often mysteriou .'Iype of tooth failure IB,

    failures oIIBevel-~Helica'l G:earUnits on Traveling IBrlidge CranesResearch and a case study on these usually catastrophic failures 2&

    Your 'Complete IGuide to :Sourcingl the Gear IndustryBuyers Guide Special Section 33

    Products and Services Direclory 35,,33' &-,-Company Directery .

    Pub'lisher's PagePau e for IMTS -2000 1

    RevolutionsThe SCRAM Variable Transmission, New Currents iI'I Deburring,and Improved Diamond Dressing " "" 91

    VieWipointBob Gerhardt of Amarillo Gear commen .on old-world expertise , ,t4

    Technical CalendarDon't, mi .the e important upcoming events 16

    Advertiser IndexFill out the card or go onfine W request :iruonuatio,1Ifrom our advertisers 117

    Industry' N'ewsFind out what' happening iI'I the gear industry .31

    Product Ne,wsRead about the tatest product for the gear industry :13

    ClassiliedsServices, Help Wanted and mere .' _

    Cover IpholD ,courtllS)' IdSUlmericl. Oak Parte.-~l

    AddendumWhat's :in a Name? L

  • CIRCLE 103" GEAR TECHNOLOGY

    EDITORiAlPublisber & Editol'.InChief

    Michael Goldstein

    Managing Editor William R. SlOtt

    Technical EditorsRobert Errichello

    Don McVittieRobert E. SmithDan Thurman

    ARTArt Director Jean Bartz

    ADVERTISINGAdvertising Manager Patricia Flam

    Advertising Coordi~tor Susan Brandt

    CIRCULATIONCirculation Coordinator Dina Krauss

    INTERNETInternet Editor Dan MacKenzie

    Gear Industry Rome Pogent SalesPatricia Flam

    powe,.transmission.com TM SalesRobert Poll

    RANDAll PUBLISHING STAFFPresident Michael Goldstein

    Vice President Richard GoldsteinControUer Valerie Hayes

    Art Consultant Marsha Goldstein

    Pbone:847-437-6604Email: [email protected]

    Web: www.geartechnology.comwww.powettransmission.com

    VOL 17. NO.6GEAR TECH.NOLOG'I:', Th. JIIU11lIII er GearMlllluI'lId.urtJI& rlSSN 074)6858) to publtmod biOll

    Journal of Gear Manu! ~ Lunt Av ue, P.O,80 1426. EIl

  • 18ringingl You GlloballlExpertis!e IFor AU App!liic,at'ion:s,

    '. Combining lOver 1'40y,ears IOf pmcessing experiencefor customer broach ana Igear manufacturing needsw0I1dwide

    '.' Able to provide "Best Practice~ solutions derivedfrom our global presence

    Technical and servlee support for your machine andtool applications

    For more information look tJl) our web site atwwwnachimtc.com or comact us at 11A810~263A01100

    Nl\CHiNACHII MACIHINIINGI liECHNOLOGY CO"17500 Twenty-Three Mi laRoad, Macomb, Michigan 48044-1103Phone: (B10)-26J.Q1(X) Fax: (810)-2634571' www.nachJmlc.com

    CIRCI.E 186,

    http://www.nachJmlc.com

  • Yin 111~llu[, 11111IIC:IIllllnl ,',1, IIIlut III!! lUll, IIIUn""""'llven plastic andpowdered metal-is an M&M GRS-2 Double FlankGear Roiler System with PC/Windows8-:basedanalysi s software.

    Iuntln CUI.II'1 In lulu. Perform totalcomposite, tooth-Ie-Iooth, runout and nick or burrtesting in seconds with the push 01 a :button. You rmach ine tool or cell operator can determine ,gearquality and monitor manufacturing processes withvery little training.

    hi IIJlII.IIUiI ul 1IIIIIJlile PinUs clearlydisplayed on the monilor or printed on standard paper,For easy intefface with SPC software, lest resu lIs canbe saved automatically in database format And M&McompOSite roll testers, like aU M&M functional gages,have a track record of proven reHabi Iityand vi rtuallymaintenance-free service,

    fin II'll III .IUIPI.Please :[;all (9B?) 859~8273or fax (937) 859-4452.IE-maillnfo@mmprecision,comand visit us on the web at WI\W,mmprecision.com.

    C 2000 M"M I'llCisiDn Syst'ms CO//lDfilion

    CilRCLE 165

    AU Gieiar TViples:, IlnclUldlillnlg

    'The

  • - --- --------~---------------

    PUBLISHIE:R'S PAGE _

    - - ']es.When you go to ... In fact, it seemed to me that many of the ,exhibitors were just going through the m tions.

    Sure, they shined up their best machines. They put on their show faces and wore their show

    suits. They had fresh brochures, new signs and impressive displays. SuperiiciaUy, it. was mesame as an.y other IMTS. But as 1 walked around the Gear Pavilion and spoke with the

    exhibitor , it became clear that something was missing.

    For the exhibitors, thai.' omething was the l.IIrong of buyers who usually come to lMT'S. Many

    or these exhibltors spend hundreds ofthousaads of dollars to beat lMTS. and iflhey'r-e notmaking sales, or at [east generating good leads, it' easy to see why 'their level of enthusiasm

    might be down. Many gwne]y said that although the numbers were down. the qualilyof atten-

    dees was high. They put their best spin on the situation, but you could read in their faces how

    they really felt.

    The cenarioat ruTS i currently being played out at the naticnal level. Industry in Americaseems, to be in pause mode, as if we're taking a collective breath. waiting, to ee what's around

    the comer. A brief pau e is typical around IMTS time, a manufacturers scale back their pend-

    ing to see what technologies will be introduced at the show. The uncertainty in 'the world econ-

    omy isn't. helping, either. Although the U.S ..economy eems to be continuing its teadygrowtb,

    'the trong U.S. Dollar is probably hurting overseas ales and contributing to dropping import

    prices. Add to these factors me political. uncertainties of this big election year and you can begin to understand the lade of excite-

    IMTS, you expect to see

    hoopla. The mass of

    machines and bodies

    should create an unmis-

    takable level of energy

    and enthusiasm. ~MTS

    2000 seemed. uncharac-

    terisucally quiet ...

    ment at ilMTS.Well, IMTS i over, and soon. the pre idential election will be 100. Frem wh 1I've been hearingand reading lately. '!he economy

    may be ready for III new round of ,capital pending that hould help boo t the gear induslIyand th.e manufactlLring sector in general.

    rer example.economi t Dr. Mike BradJIey, whose column is featured in me AGMA New Digest, recently wrote that we m_ayhavereason to be positive about the outlook for the gear industry .in 2001. According to Bradley, the overall economy saw a sllift from con-

    sumer pending to capitalgoods spending inlh first ha:.lfof the year, with capital goods spending increasing in each of the months

    from March th_rough June. This growth in capital good spending, although slim, came ala time whenlhe Fed rnI Reserve was inch-

    ing up interest rates, H!he manufacturing sector can continue to withstand these increases. and if recent data on industrial production

    are any indication, the gear industry COl.lld see 3. po itive 20m, Bradley ay.

    1. for one, am not going to worry aboul what E aw at IMTS. Even though the how lackedits u WlI.energy and enthusiasm, there's no reason to panic. Like the rest of the manufacturing

    sector, we've got to wail and see what happens ,next With any luck, orne of the indicators we're

    seeing now will gain momentum and make 200 1 a very strong year for the gear industry.

    Who knows'] By the time Gear Expo r-olls around next October, wemay even see smiles

    returning to the face of the machine 'tool vendors.

    Michael Goldstein. Publi her and Editer-in-ChlefNOVEI.IBRID!CIUI!I! 2000 "

  • REVOILUTIO:N!S 11 _

    SCRAMIAccording to wts inventor, John

    Hammer:beck, the revolutionary thingabout his Simple Continuous RatioAdjusting Machine, or SCRAM, a newdesign in infinitely variable transmis-sions, is its belt. "Previous systems. alluse the interaction of cIilIering diametersof wheels and/or belts to change speed,"says Hammerbeck. "SCRAM uses theentirely new principle of an extendiblebelt constructed so that for a given inputat the drive point, the belt will loop pastthe drive point. in a fixed time howevermuch the belt is extended, When the beltis extended.a greater length. runs over anoutput wheel, making the output. faster;"One version of 'this system uses a ten-sion coil spring as the belt. which isdriven by lugs mounted within a hollowdrive shaft and interacting between thewindings of!:he coil "Turaingthe shaftcauses the lugs to propel the coil for-ward," says Hammerbeck. ton wiU beapparent, as the number of windings ofthe coil does not change, that for a giveninput R~M, the belt will pass the drivepoint in a fixed time."

    According to Hamrnerbeck, this sys-tem has a number of distinct advantagesover traditional gear drives and other"in.finitely variable" systems as both areduction mechanism and a speed eon-trol mechanism for both commercial andindustrial applications. One of theseadvantages is that the technologydepends on well-understood parts andprocesses. To the question of metalfatigue affecting the spring belt,Hammerbeckacknowledges the pI10blembut answers, "Yes, but springs an) stud-ied and understood. The valve springs. inyour car do 500 million. cycles whde youdrive 100,000 miles. Have you ever had

    a valve spring failure? The fatigue char-acteristics of compression springs are thesame as extension springs." Other advan-tages include smooth, continuous ratiochange while under power, a wide rangeof ratios. precise speed control, no back-lash, little vibration, good heat dissipa-tionnnnimal lubrication and others. It isalso easy 1.0 control, since there are nocomplex gear changing linkages,andeasy to work: 00 since there is no casingand no oil bath. The unit has a standardreduction of 25 to I,which makes itsuit-able for high RPM input, but this can bemodified to suit the application by speci-fying different springs or placing units inseries. It can also buffer input energy,automatically storing it when outputmeets resistance instead of slowing thepropulsion unit.

    "SCRAM is an extremely cheap, lightand effective ratio a1.tering machine,"says Hammerbeck, who came up withthe initial idea while working to developan acceleratiag moving sidewalk. "Itsability to take the most efficient, steadyRPM from the power source andacceler-ate the system to high RPM without dis-engaging power gives it considerableadvantages over previous systems,andits low cost will spawn new applica-tions. " Consumer applications for thi stechnology include systems in both con-ventional and electric vehicles, house-hold appliances, videotape machines, gar-den machinery, electric motors, bicyclesand climate control, Industrial uses wouldinclude compressors and hydraulics, tex-tile machines. machine tools. centrifuges,oil drills. lifts and conveyors, marinepropulsion, wind generators and specialvehicles. These last could include solarpowered vehicles, lunar and amprubiousvehicles, and human-powered flight."Bu:ifering of power could e-nablerowingaction and. therefore, fuller utilization ofbody strength than cycli-ng action," says.Hammerbeck,

    On the 28th of June, 2000, the SimpleContinuous Ratio Adjusting Machinemade its debut at the BBC 'Iomorrow'sWorld Invention Fair in London,England. The two working proef-of-con-

    ! Welcome to Revo'utions, tile co/~,umn tIIat brings ,ou fbI 18testmost up-to~dateand IIsy-to-read.info.rm.tion about ,the peopleand t,chnolog, of the ge.rindustry. IRevolu11ioDS welcomesyour submissio.ns. Please sendthem to G'ear Technology, P.O.Box JU6, flk Grove Vi'.'age, 1160009, fax (8f7) 431--6618 Dr ,[email protected].. you'd like more informationaboutany of the ,rticles thst SPPBlr,pleBSe eire/e the a,pproprists num-b" on the Resder Servic, Card.

    cept machines reeei vee! wbatHammerbeck calls a "tremendousresponse" from. engineers in a variety offields. Hammerbeck believes the rangeof apphcations for his inve.ntion is verywide because it makes continuous andautomatic speed control very cheap. Theunit itself has no casing and no, gears tocut-just. wire, plastic and fastenings. "Iimagine that it ll'lightbe used first in funapplications like Robot Wars," saysHarnmerbeck "These devices are veryeasy to make, so I hope many amateurswill experiment with them, "

    Clrde301

    New ICurrents in DeburringMost metalworking processes leave

    burrs and other attached materialresidues that need to be removed before!'I part 'can be put into service. The morecomplex the part, the more ,difficult thetaskof finishing it. Now, from 3CDGI'adningst.ekmologi. AB. we have adeburring and polishing process thatworks w:ith even the most complex anddifficult to machine parts. Caned the3CD Process, this electrolytic polishingand deburring method promises to leaveparts burr-free, with smoothedges andcomers and a soft. clean surface with alower Ra-value,

    mailto:[email protected]..

  • _ --.-.-. REVOLUTiIONSThe Process. For simple work-

    pieces, the part to be processed is con-nected to the machine as all, anode (pos-itive pole) in a direct current voltagecircuit with a cathode (negative pole).An. electrolyte solution (electricallyconductive fluid) consisting of glycoland three different ammonium saltscompletes the circuit This solutionmaintains a. pH level of 6-7 and has aworking temperature of 15-20" C.

    - - --- - - -

    - - --- - -

    According to Bo Magnusson, market- iing manager for 3CD Gradningsteknologi I~~~;:!~~:~:~~e:~:;ti~:7;IIcharged ammonia ions. When the ,currentcircuit is established. the chlorine ions

    move towards the anode and at the urface I',join the pos.itvely charged iron ions"removing them from the work piece!

    !i

    anode. in the electrolyte. the molecule Isplits and the iron ions join free OH-ions I I

    I The aCI) deburring Ipr,oceu.

    Ii and fall to the bottom as Fe(OH)2' The

    OH-ions form as a result of the electronmovement in the current circaii, At th

    II, cathode, water molecules are plit into an.

    Hz gas and OH-ions. When '!he curren II circuit is established, the ions and theI electrons move along current lines. These1 are most frequentlylocated oa the comers

    and edges of the workpiece, where youfind more deburring activity,"

    After completiog the deburring andpolishing process, the part is then washedand rinsed. For more oomplex pieces"locally positioned auxiliary electrodes areused 10 direct the current When debur-ring or polishing interior spaces on II pan,such as intersecting holes, the process canbe performed on a specially designed rigwith auxiliary cathodes applied to theareal where debu:rring is to be carried Ollt.In these cases, the electrolyte is routed tothe area to. be machined by means of ahose and drained via a collection paninloa pump-fitted system tank.

    Materi.aI removal is directly propor-tional to the current strength and time.However. the material removal rate is alsoinfluenced by such parameters as the COI11-position concentration, flow, temperature,electrolyte conductivity, the tendency ofthe metal to become passive, and thealignment and pulsation of the current.Still. llIe process is entirely safe for theworkpiece, says, Magnusson, "The elec-tricity does not affect the work piece atall," lie explainsYfhe debarring processcan also offer the positive effect ofremov-ing cracks from the surface.' The processis designed 10 handle bum !that are Ie sthan 2 mm in size and is capable of pro-ces ing a pan in 2--4 minutes whenlheburrs are about I. rom in ize.

    rrw has provided the gear industrygaarlD8pectlon devices. Put your trust in.

    the people who invented the process.

    AVAILABLE:lit Manual double flank testers for ccarse pitch.

    Manual double flank testers for fine pitch. Computerized double flank testers for

    coarse pitch. Computerized double fl'ank testers

    for tine pitch. Dimension over pins or balls, Automatic In-line gauges.

    No matter what the application; coarsepitch. fine pitch, externals, internals,

    shafts, metal or plastic - we lookforward to working with you.

    Model 2275-00PDimension (MIl"

    PN or Barfs

    CompUlenz.ed roll 'tester for composite -

    and lead

    ITrfJf Heartland1205 36th Avenue West

    Alexandria. MN 56308 U.S.A.Ph: (320) 762-8782Fax: (320) 762-5260

    E-mail: Itwgears. rea_com

    10 GEAR TECHNO!LOG'f116

  • REVOLUTIO,NIS I:. --- _Parts and Tooling. All parts can be

    treated. However the method is most prof-itable for parts with a certain value andwith a high demand for burr-free surfaces.The size of the parts that nmy be treateddepends, all whether fuey must be placedin the electrillyte or not. Large surfacesdemand more voltage, and the bum. onthem tend to be less concentrated,Whether a hole can be treated depends onits depth, placement and diameter.Normally, holes with diameters of 2 rnmor more can. be treated. Threads on a parttend not to be a problem.

    Different pans. ona gear are usuallydebarred separately, although gear ringscan be debarred all at once. "Any gearpart can be debarred, but you have to usespecial cathodes/tools for differentparts," says Magnusson. "Depending on!he production method, you can transportthe parts on a belt. conveyor or pick-and-place robot into the debarring area, au.to-matically apply the toots to the parts,deburr, remove the tools and then restartIlle conveyor or robot for tile next part."

    M:aterialsand Tolerances Any elec-trically conductive material, with theexceptions of titanium and zinc alloys,can be Ireated . .Alloys with silicon andcarbon can be processed; however eachposes its own unique problems. The sur-face of alloys with silicon end the processcovered with silicon oxide. Carbon COD-tent decreases the effectiveness of theprocess in proportion to its amount, In.other words,lhe more carbon, the lesseffective is the process. Under normal cir-cumstanees, the meta] removal rate for theprocess is 0.005 rom/min, a rateMagnusson says designers can count onwhen working out part tolerances.

    The metal that is removed is dis-charged as hydroxide slu.dge. This couldbe environmentally hazardous if themachined components contain heavy ortoxic metals. For this reason, sludge fromme electrolyte bam and rinsing watermust. be separated before being dis-charged. 3CD Oradnillgsteknoiogi ABoffers its customers solutions and equip-ment for this type of materials handling.

    AocOIding to,3CD GradningstelrnologiAB, the flexibility of the 3eD process and

    its versatile range of use offer a highlevel of utilization, creating economicbenefits for the user. This is regardless ofwhether the process is being used in ashort-run job shop or on an automatedproduction line. Other benefits stemfrom the energy-efficiency of the processand the long service life of the elec-trolyte solution.

    Improvedi IDiamond Dress'erContinuous gear grincling is one of me

    most important grinding processes for themanufaeture of high precision gears. Thegrinding wheel, fanned with a nICk andtooth profile, is used as a cylindrical grind-ing worm, The involute profile of the grind-ing WOTIll is fbrmed and maintained bylheprofile of a diamond dresser disk.

    The quality of the gear tooth flankdepends 011 the accuracy of the involute

    Circle 302

    S'andw;,ched betweentight specifications a'nd a.ne'ven tighter deadli'n,e?

    Let Milwaukee Gear's custom gear se~;ces prepare' yourproject your way.

    Engineering and design services Prompt, accurate quotes Competitive pricing Cost-,effective manufacturing Complete heat tre.ating capabilities On-time delivery

    Supersized orders or small, we have the expertise and equipmentyou need for AGMAGS through 014 precision gears and geardrives. ,ill/ topped with the best service support in the industry.

    zo. Box 1170615:5150 N. Port Washington :Rd.Milwaukee, WI 532178091Tel: 414962-3532 Fax: 414-9622714E-mail: [email protected]

    CIRCtE 119

    NQVEMIIERloeCEMIIE'R a e e e n

    mailto:[email protected]://www.milwQukeeg.ear.coml

  • REVOLUTIONS, _

    fonn of the grinding wheel. Advanceddesign gearboxes utilize special gear toothforms to improve noise and operatingqualities. Gear tooth modifications. suchas tip and root relief created by a combi-nation of two radii or a radius and straightline in addition to simple crowning, areformed in the grinding wheel by use of aprofile form diamond dresser disk.

    The lifetime of the diamond dresserdisk is an important consideration in

    continuous gear grinding. Diamonddresser disks are available with a direct-or reverse-plated single diamond layer,or with a sintered single or multiple dia-mond layer. Sintered dresser disks offer along life and have excellent comer wearcharacteristics. Sintered tools also utilizehigh dressing pressures and cannot pro-duce as sharp a grind.ing wheel as can adirect plated diamond dresser disk. As aresult of the excellent TJ.R and more

    aggressive diamond layer of the directplated diamond dressers, the grindingwheel is more aggressive and free cut-ting. Direct-plated diamond dressers canbe refurbished or modified by strippingand re-coating the diamond layer and/orregrinding the profile for a differenttooth profile.

    Sintered and direct plated diamonddresser disks can be re-lapped to restorethe original involute profile; howeversintered dressers cannot be re-plated,

    A new generation of polycrystallinediamond (peD) corner-reinforced, directplated diamond dresser disks. designedand produced by Dr. Kaiser DiamondTool offers the advantages of both sin-tered and direct-plated dresser disks-high corner wear resistance and a freecutting grinding wheel. The combinationof reinforcing peD to counteractexces-sive edge wear on the outside diameter ofthe dresser disk, and direct-plated dia-monds, improves gear grinding anddresser disk life equally. The direct-plat-ed, pcn reinforced dresser disk can bestripped and recoated several. times.Tooth form modifications such as fiprelief or crowning, for example, can bebuilt into the dresser disks.

    The new generation peD reinforceddresser can be utilized ooall oommondressing units, Small module applica-tion s offer a distinct opportunity forprocess improvement since the smallwidth of the dresser disk can wear quick-ly. Tile peD reinforcement leads toexceedingly long diamond dresser life,particularly if a separate root reliever03l11l0tbe utilized.

    Cin:le306

    Yesierdau's ReliabilityTomorroio's Technology

    Ten Us What You Think ...

    Fifty years of VARI-ROLL applications provide: Production Composite Inspection Custom Design & Build Part Gear Mounting Fixtures Standard Mounting Fixtures - Spurs, Helicals, Pinion Shafts,

    Worms, Throated Worms, Bevels, InternalsWhen coupled with the VARI-PC Composite Gear AnalysisSystem win provide: Reduced Inspection Cost Improved Accuracy Historical Record Keeping Serializa tion of Parts Interface to SPC programsExperience the difference. See why customers worldwide havechosen the VARI-ROLLIVARI-PC. For further information,please contact us.

    .1(4Rj -ROLLPrecision Gage Co., Inc.

    ]00 Shore Drive Burr Ridge, [L 60521630-655-2121 Fax 630-655-3073

    www.precislongageco.com

    If you found this column of interest and/oruseful, please circle 304.

    If you did not care for this column circle 3D5. I

    If you would like to respond to this or anyother article in this edition of Gear Techn- ,o{ogy, please tax your response to theattention of Randy Stott, managing editor, at847-437-6618 or send an e-mail messaga topeople@g88rt8chno{ogy,com.

    CIRCLE 233

    12 GEAR TECHNOLOGY

    http://www.precislongageco.com

  • ------IVIEwpmNT

    Dobbing, CNC generators, power cutting, dry cutting, and whoknows what else.

    So what is "old world machining expertise" and where doesit fit in today's world? Ibelieve that old world expertise is a pro-found understanding off the manufactured part, and how it isphysically (not just electronically) made. When you get rightdown to it, gears are still made by removing material from thegear blank to form the tooth gap. We use electronics now to putthe blank where we want it and to put the cutter where we wantit, and to move them both the way we want them to move. Thesuccessful gear technician 00 the plant floor is the one whoknows why.

    Old World ExpertiseDear Editor,

    I am writing this in response to some articles appearing inyour journal, but Iwant to take the opportunity, also, to expressmy thanks for all the good work: your publication is doing. Ialways look forward to your next issue being in my mail slot. I

    know Iwill findnmely technical articles relevant to our manu-facturing situation here at Amarillo Gear Co., as wen as thoughtprovoking commentary on events and trends affecting our busi-ness, The Publisher's Page is always worth the reading.

    I would like to comment about remarks made in yourJanumy/February and July/August issues by Mr. Joseph L.Arvin, President, Arrow Gear Company. Mr. Arvin is right onthe mark concerning the loss of what he calls "old worldmachining expertise" in the gear industry.

    Ibegan working for my father in his automotive repair busi-ness when I was 8 years otd; My first job was to keep the shopclean and make sure all the tools were accounted for and in theproper place. When I mastered that, [ was allowed to dean partsfor reassembly. Later, Iwas taught to disassemble. paying closeattension to how the mechanism was put together. After thatcame hands-on reassembly. Finally, Ibegan to learn about diag-nosing problems and executing the repair ..

    Each new level of training was built on a necessary founda-tion of previous] y mastered skilland knowledge, First, [ learnedwhat the tools looked Iike, how they worked, how to pick thebest tool for the job, and how to keep my work area clean and

    organized so I could get the job done. Then I learned what theparts looked like, what their names were, where they fit in the

    mechanism, how they contributed to its function, and what mal-function could be traced to a particular part. Only after all thiswas learned could .I beginto understand how my father knew .what was wrong with a vehicle and how to repair it.

    I was 24 when I started my career here at Amarillo GearCompany, and the learning process is the same. "This is a spiralbevel gear, and this is how itdiffers [rom the hypoid gears yousaw in your dad's shop. This is the convex side of the tooth andthat is the concave side. This is called profile, and this is called ~

    bias. This is how lapping works, and this is why we lap gears!in sets, This is called a tooth contact analysis. Can you see Ifrom this how the motion of the gear tooth in relation. to the !pillion tooth transfers the power? This is a face mill cutter. The imachine moves the cutter in the same path the mating gear i TeU Us What You Think ...

    If you found this column of interest and/or useful, please circle..tooth will make asit passes through the tooth gap, thus gener-ating the tooth. gap as it cuts ..These are proportional changes If you did not cara for this column, circle".that you can use to adjust bias and profile to improve the bear- If you would like to respond to this or any other article In this edition ofing pattern. Now that you've mastered fixed setting method, Gear Technology. please fax your response to the 8IBntion of Randywe bought a new machine that does duplex. cutting. We will '. Stott. managing editor at 847..43HI61S or send HI1all messages to

    [email protected] both sides of the pinion at one cutting.' Now comes face: L- JI

    14 GE.-.R HCHt

  • .ew manula,'uring,apa"ty

    readyl

    .ATA Gears Ud. has gained worldwideopprova.' as a manufacturer 0', 'dgh ,qualityspiral bevel gears - with '-he ,help of professional'experienc,eover 60 years and modern' technology.

    Our main product is spiral bevel gears up to 2S00mm ( 100 in) diameter. Our experience in handlinghighly dassi[1ed materials, our universal gear cuttingsystems os well as our own heat treatment spotlightas a gear producer for demanding customers such osthe off-shore ond mining. as well as the machine tool-and heavy vehide industry. ATA'sgear ffnishirtgmethods.lapping. hard cutting and grinding. enable accuracyclasses up to DIN Q=4 (AGMA Q= 14).AToll. Gears, Inc.19885, Detroit RoadRocky Rjyr. Ohl'o 44116,Telel:Fax.: 440-356-0'289

    In addition to spiral bevel gears ATA alsomanufactures custom tailored complete gear units fordemanding applications. TheATA productdevelopment work is remarkably represented bypropeller-turbine operated small electric power plants.''Tum-key",service-free hydroelectric power plantsproduce, with falls of 2-20 meters, power capacity of20-2500 kW Hydro turbines demonstrote in Qmagnificent way the scope of applicotJon for ATA'sproduct development

    ATAGEARS LTDIMJ!lJiI1lJ address: P.O. Box 120'. FIN-3JIOI Tampere. FINLAND

    Tel +3.5832870 I r I, m+358 3 2870 2

  • CIRCLE. 136,16 GEA!R TECHNOLOGY

    B.ENOLDPrecision Technologies

    i TECHNICAL CALENDAR _

    Nov. 5-10, 2000-ASME International MecbanicalEn,gineering Congress and Exposition. Walt Disney WorldDolphin Hotel, 'Orlando, FL. The theme of this year's conferenceis Beyond Traditional Boundaries ..The event will provide one ofthe engineering industry's premier forums for industry. acade-mia and government, w.ith hundreds of technical presentationsscheduled. Call ASME at (800) 843-2763.

    Nov. 6-10, .2000-AGMA's Training School for GearManufaduring Basic Course. Daley College, Chicago, IL. Thebasic course is designed primarily for employees with at leastsix months of experience in set-up or machine operation. Thefive-day course is split into classroom and hands-on training ses-sions. Students will learn to set up machines for maximum effi-ciency. accurately inspect gears, perform gearing calculationsand understand basic gearing ..Call AGMA at (703) 684~02i 1.

    Nov. 29-Dec. 1, 2000-Fundamentals of Gear Design, Part 1of 2. University of WisoonsinMilwaukee. This course featuresRay Drago as instructor. The course content has been updatedand expanded to provide a more comprehensive coverage of theimportant topics regarding the fundamentalsof gear design, Part1 includes history of gears, basic gear tooth nomenclature. typesof gears, gear arrangements. theory of gear tooth action, and fail-ure modes and prevention. The full course (Part land 2) isspecifically aimed at the designer, user, and beginning gear tech-nologist. The main emphasis is on the proper selection, designapplication, and use rather than fabrication

    Jan. 16-18, 2000-SME Advanced Productivity Exposition,(APEX). Orange County Convention Center, Orlando, FL. Thismachine tool show is sponsored by SME, AMT-The Associationfor Manufacturing Technology. and AMTDA-lbe AmericanMachine Tool Distributors' Association. CaB 5MB at (313) 271-1500.

    100 You H'ave' a,'lechni.cal Event You'd Uket,o Promote?Send N'ews R.eleases toGear Techn%lIY.P.O..Box 1;426,Elk Grove, IL 160009

  • ----

    AIDIVERTIISER IINDEXFor mon infomlatioe about product or urviCI .dvertiud inthi' iaul of Gu, TIICIuHII"". circle t118.pproprilll numb.r onl1li ReatIer Reapoae card and pili die card 1ftthe mail.NEW! TRY OUR RAPID READER RESPONSE SYSTEM'00 to www.fNIIKMolorw.cWm;hR to request Iddition-.1 I~ Ira. MY adOrtiur in this ..... Your requestwill be II1d to Ih Idnrtiur within Z4 houn faf luplr-fatlIIm.roundl

    ADVER1IIS'ER

    AJW SylenlSAGMAAjax M'agnetbermicAmarillo Geu Co.American Metal1"ruting Co.American, Wen!AppLied ProcessASI MachineryAJA 'Geani Ltd!.Barit Intemational Corp.Basic Incorporated GroupBeeGf Gcan:neisn:rsBourn &. Koch Machine Tool Co.CoB Gear MachineCro\IFn Powenrain s.r1.Cnlcible Service CenICl:SDura-BarDyer Co.ElMCOU.CEmug~Cmp.Engineued Heat nut. Inc,. slerlFelkrw Carp.(,LeasoIl CorpgrntiOIl'Gleason CUlting ToelsHofler Maschinenbag GmbHHolroydIndex TechnologiesInsco, CorporationITW HeartlandKeepfer America, u.c!fum Sharpening ServiceKreiler--GearttcbLaser Machining, tee.LeCount. Inc.Leistritl:M&.M Precision Syst= Gorp.M:aru- FedernIMicro, GearMidwesc. Gear &. Tool

    :Udwesl, Gear Corp.Milwaube Gear Co.

    achi M hining Teclmology 'Co.Lagara G~ Corp.

    Ohio Broach &. Mac.him: Co.Oil-Line ServicesParker IndustriesPerry Technology Colp.Precision Gage Co.PTesrite CorporationProcess Equipment Co.Profile EngineeriDgProfile GearPro-Gear 'Co . Inc,Punly CorporanonQuality 'rransmission CcmpenentsRaycar Gear &. Machine!REM Chemicals, Inc.R:oto-Teclmology" locoRussell. Holbroo &. HendersonS.L. MlIIlSOnStar CUUer Co.SU A;mericaSuhDer ManufacturingSurface CombustionToolink &giotcring

    IREADERSEllYIC'E NUMBER

    111.176129.214117.215

    21.6163

    130',217148,2181.53,219U3,241141,177149.178

    164151.179109.221.167,220'13.5.181.ISB,235

    239224,225103.1112

    246131,231.

    2431.10

    105, 1.66. 184112. 185136. 188237.238152. 189116.190

    236[9J169

    137,192142, 193226,227165.198

    242154.1.95155,196

    nO'119, 197186,200

    171144.172.201

    146,202156,203134,204233,214108. 20'S123,206

    173232174

    125, 207157,20'8

    228127.209160.2.10141,211222,223

    132, 229. 230107. 212.,62,2.131I:5,2M)'244.245

    P!AGENUMBERI

    46,1285,5460,55

    5386

    76,4981,1237, 7515,4938,4463.56

    8678,5325,5978,n34,:5947,45

    5416,584, 7545

    57.:5059

    lFe-1BC,.86,40'

    8.4816.5587.5466,5810.44

    874486

    17,51142, 7541,566,5450

    65.5865,40

    8611,555.50'

    8752.87.40

    38,7579',44me, 48.12.5613,4539,55

    878187

    36,4879',45

    8743,5366.4942.5351,59'

    2. 87, 4832.5681,49'82,5063,n

    IISOLUTIOIN FOR WELIOING

    & IHEAT TREATINGFor immediate response toyour specific needs, 'e-mail:

    dplourdeelasermachlnlnc.com Q[IIkotvaletaserrnacnlntnq.corn

    OR CALL BOO-77-LASER

    V lAnH MACHINI' G.INC.-~ Providing Loser Solutions for InduSlry

    SOMERSET, WI 715-247-3285

    CIRCil E 137'NOVEMBEA/DECUI'BER 2000 17

  • Design Against ToothInterior Fatigue Fracture

    Magnus Mac!kAldener and Marten OlssoDi

    Intredncnon10 a modern truck, the gear teeth are among

    the most stressed parts .. Failure of a tooth willdamage the transmission severely. Throughout

    the years, gear design experience has beengainedand collected into standards such as DIN (Ref. 1)or AGMA (Ref. 2). Traditionally two types of

    failures are considered in gear design: tooth rootbending fatigue, and contact fatigue. Thedemands for llighter and more silent transmissions

    have given birth to new failure types. One novelfailure type, Tooth Interior Fatigue Fracture

    (TIFF), has previously been described byMackAldener and Olsson (Refs. 3 & 4) and is fur-ther explored in this paper ..

    Observations of TWFTIFF is characterized by a failure, approximate-

    lymid-height on the tooth, which distinguishes it

    from tooth root bending fatigue. Contact fatigueandlor spall.ing craters are not a prerequisite at theflank of a TIFF. In Figures 1 and 2, photos and aschematic of a typical. TIFF can. be seen.

    TIFF has been observed in case hardenedidlers. A test series with idler wheels has been

    run. Out of 75 specimens, 20 were classified asTIFF. Tooth root bending fatigue or contactfatigue occurred in the other specimens.

    TIFF MechanismTIFF is initiated in the interior of the tooth.

    Other known fatigue failures initiate at the sur-face. A failure type called Zahnkopfbruch inGerman. starting from spalling craters at theflank, has been reported by Shultz and Sauter(Ref. 5). Hence Zahnkopfbruch and TIFF are notthe same type of failure, although they mayappear similar. Alban (Reef. 6) described stress

    ruptures, which have a fracture surface similar toTIFF. However, stress rupture is 001. a fatiguefracture since the crack is formed during the hard-ening process.

    TIFF is the result of: 1) COllistant residual ten-sile stresses in the interior of the tooth due to casehardening. and 2) alternating stresses due to theidler usage of the gear wheel.

    Ana1ysisFE-model/or mesh cycle simfliaJiD.n.To ana-

    lyze the crack initiation process in the gear, a 20.FE-mesh was utilized, A plane strain 2D-mesh inthe normal plane (perpendicular to the flank) was

    shown to give stress distribution in a. cross-sec-tion of the tooth that is virtually the same as thatof a 3D-mes'h. Hence a 2o.-mesh can be used forstress analysis of a complete mesh cycle. The FE-mesh is shown in Figure 3.

    With a parametric model of t11eFE-mesh(developed in ANSYS, Ref. 7), an arb:itrary posi-

    .- ---, I lion in the mesh cycle could be analyzed. The

    gear calculation program LDP (Ref. 8) computed

    the total force on one tooth as a function of posi-tion in the mesh cycle. The tooth force was divid-

    ed by the width of the tooth and applied as torque.The residual stress due to case hardening was

    found by applying an inelastic strain profile inaccordance with residual stress measurements.The hardness penetration depth and ilts shapewere obtained by hardness measurements ..

    Fatigue tests of the gear showed that shot peen-ing increased the fatigue endurance limit by 36%.

    Fig. I-A typical 'looth Interior Fatigue Fracture (TIFF) and a schematic of aTIFF.

    Fig. 2-Close-up 01 a cross-sectional a TIFF. The wing crack indicates thepropagatio.n direction of the main crack (from the interior of the tooth towardsthe}ltink). .11 GEAR TECHNOLOGY

    --------

  • Residual. stress measurements of shot peened gearwheels showed that the . hot peening increased thecompression stresses to a depth of 0.1-0.2 mm.

    Crack inilialio.n criterion. In order to predictcrack initiation in high cycle fatigue during mul-tiaxjall.oading, Findley (Ref. 9) suggested a.criti-cal plane approach where the shear amplimde ft.)and the maximum aormal stress (O'n.mnx)duriQgone load cycle are used to form the criterion. Thecriterion can be written

    0'1' = '''!:tilwltere

    I an equation for effective fatigue stress (findleycritical plane stress}. The criterion states that crackinitiation will occur if 0'1' is greater than. 0' ,crlC' Here,O'erll and acp are materia] constants that can bedetermined by combining the result of twofatigue tests. Here. 0'''';1 in the core was, deter-mined 'W' be 'O'crit.mrc= 479.8MPa while for thecase" O'cril.

  • seated by an FE-anal.ysis determining the ClRF inthe unerior of the tooth.

    Result of the paramete,. study. The result ofthe factorial design is the CmF (response) in theinterior of the tooth denoted Yi for the ith experi-ment (Table 4). Emanating from the results it ispossible to estimate the main effect. The maineffect should be interpreted as the change inresponse while changing the level of the factorfrom low to high. The main effect is given by

    . [J.:+ [Ie,mN+ "" -k+ L .Yi+-T L ; (3)

    i=l i=lwhere k+ and k- are the number of times the fac-tor appears at highand low level, respectively ..The result of the factorial design is summarizedin Table 2.

    In Figure 6 the average of the factors regarded!as significant is plotted. The main effect is the dif-ference between the low (-) and l1:igh(+) level foreach factor ..

    The greatest ieffuence 00 the CIRF ill theinterior of the tooth comes from the factors A(Gerlt). C (slenderness ratio), E (tooth load) andB (acp) in that. order. The influence 011 the CIRFin the interior from the factor D (the carburizingdepth) is less than 5% but, somewhat unexpect-ed, it is negative. This means that the lower theearburizing depth, the higher the risk of HFF . .Itis also worth noting that the influence from thecarburizing depth (factor D) is less than theinteraction effect of O'eril (factor A) and the slen-derness ratio (factor C).

    Since it is desirable to have as Iowa CIRFas pos-sible, the optimal.settings of the factors are A+, B-,C- and E-, meaning high O'eril in the interior of tiletooth, low slenderness, low tool.hload and low acp'

    Engineering Design Metb.odWhat so far has been shown in the present

    paper is that it is possible to predict and analyzeTIFF by applying the FEM. However, this .is timeconsuming and not appropriate in the design stageof gear development. Therefore. an "engineering

    Aller:ageof factors and Interaction

    Fig. S The sle1lder (left) and not-slender (right) geometry compared "".itk the geometry olthe original tootl, (middle).

    D.1

    -.l r .t-\-.--..--L-----L-----..L--~----~~-.-~""----.,,...d-

    ~ j j

    oeos.

    ~104

    ~ 03

    C; 0.2

    01

    o.... A+ C-C+ E-E+-

  • design method:' (EDM) was developed and imple-

    mented in MatLab ..Adesign method based on superposition of

    elementary solutions. Two basic assumptions areassumed for the EDM. These are:i) The critical Findley plane is assumed to be per-pendicular to 'the center-line of the tooth.ii) Stresses itt the tooth interiora:re expressedusing elementary solutions of elasticity theory.Normal stresses are estimated by beam theory.Shear stresses are estimated with the half-spaceelution combined with beam theory,

    Basically, three types of superimposed stressstates, acting on the pre-assumed criticalplane,need to be considered. These are i) residual stress-es due to case hardening ii) normal tension stress-es due to bending and ill) shear stresses.

    Residual stress. Abeam (or roo) with varyingem s-section can appmximate the tooth in the

    residual. stressestimation .. In a surface layer wilhthickness dCeqv. a constant volume expansion ~ isprescribed. A sketch of the simplified tooth can be Fig. 7-Simplified tooth.seen in Figure 7,.

    The width of the tooth is b, the height is II andthe varying tooth thicknessas a function of thediameter dy is given by syn(d,J The stress in 'the y-direction in the interior oflhe tooth can beneglected. By assuming that stresses are homoge-

    nous in case and core, respectively. and combin-ing equilibrium and!Hooke's law in the x- and z-direction of the toollh. the folowing expression ofre idual stress is derived:

    A

    (s .(dy) - 2dc +b)O'x-core= O'n:s

  • II

    \! F(dI x

    Fig. 9-Elastic half-space estimatio.nof the contact problem in the tooth..

    - of(x=o.z)'-+ T,.Vx= iJ,z)

    F

    Half.""solution

    r -,-,-,-o'/(x.z=s,..!

    Z 7 .. 1(x: .z=s,.,J

    Half-spaceslrcsses onf.} and 4

    !F

    P ~TXzI

    )

    Siresz - -

    x-

    s freeboundaries

    Fig. 10---S~perposilion of elastic half-space solution and compe.nsatingsolution.

    Comparison between EDM andl'Elullits

    1.4 -,----------------------,

    1.2 +---.....,...,....-.------=--------,~----__=_-____I _jj~ .... _, oW ....... !Ii -,I.. . _'.,lII ~-

    !!f

    :s..,"i0.8; 0.6 -ta.--flI+r------.;~!__-----I'-----~_IPtr+_~~___1H

    u

    I ---tr-CIRF .EDM..... [CIRF.EDMV[C'RF -FE)

    0.2 +------------"'--1

    O~~~~~~~rT"_.~,_rr~-rrT~_."~- '" It) I"'" OJ - roLO ,.... (I) ....' '" It) r- en

    ..... '!"" N N N N N ro

    F~g. l1~Comp.~ri'son of the CIRF calculated with the engineering designmethod and the elRF according the .FE-calcu.lationsin the ptirameter,study;22 GEAR TECH'!I!O~OGY

    tile tapered tooth is approximated! by a. beam, withconstant thickness, The superposition technique isillustrated in Figuce 10.

    Consider the compensating solution (in Figure10). The stresses on 01 and 02 in the compen-sating solution are given by the half-space solu-tion (n Figure 10). After subtraction. stress freeboundary conditions are fulfilled. Tile shearstress due to the line load! on the half-space hasbeen presented. The shear stress due to the com-pensation solution may be estimated! by beamtheory. The transverse force (T) on the studiedplane in which point P lays is given by integrat-ing the compensating solution along the bound-aries ell and 2, The latter integration shouldonly be performed from the tooth tip to the stud-ied plane in which P lays. The contributions to Tfrom the two boundaries should be added tomake up the transverse force. The 'transverseforce at P is given by

    where Xdis1 = (dy-d)/2 and S = (da-dJ,)/2. Theshear stress due to the compensating solution,estimated as bending shear stress due to thetrans.verse force T, is then given by

    TS(~'tn

    C = --I(dT")--=b--

    where S(zb) is the static moment given by

    (9)

    However, it should be noted that the compensatingshear stress should only be subtracted if the toothforce is p? itionedoutside the studied plane (i.e,~ > dy)' The !esulung shear stress at point P in aI planeat ely is thus given by

    iil'tl' '" 1: 1- 9(d - .d) 1: c (l l)

    )t~ u y nii

    I i where 9 is the Heaviside's step function. However,ii in the Findley critical. plane criterion, it is tile shear

    stress amplitude rather than the shear stress itselfthat. is used. Therefore, the maximum and mini-mum shear stress at each point is sought n is notobvious when during the load cycle the maximum

  • risk of TIFF was decreased as the carburizingdepth was increased, This unexpectedrel.a:tion canbe understood if the bending stress in the tooth isconsidered. The FE-analyses how that the regionin the tooth with the hlgnest CIRF is in the case-core boundary. Also, when the carburizing depthis low, the layer with the compressive stresses isthin and hence. the bending sires in the case-coreboundary is greater due to the greater distancefrom the center line. The conclusion is that theeffect 'of the bending stress is greater than theeffect of the residual tensile stress in the interior ofthe tooth.

    The parameter study also showed that the twofactors having the greatest influence on the risk of

    '0/ =tBP + acp;core (ores + oP olll1Dlll) (]3) TIFFareoCri1 in the interior of the tooth, and the

    slenderness ratio ..This highlights a new problem

    and the minimum occurs, respectively ..By imple-menting the derived expres ions in a computer pro-gram (here M_atLab is used), it i possible to deter-mine the maximum and minimum shear stress at allpoints m the tootlil interior, and the shear stressamplirude can. be fonned by

    max {1:. Ph.........,..1c - mini t.,n 1---110't P= . Y -,- , -J' (2) 2

    Findley str,ess. The total stress, in the radialdirection of the toolil (or in the x-direction as in.Figure 7) is the sum of the residua] stress and thebending stress. COllsequenlly, 'the Findley criticalplane stress can estimated by

    The bar over the OF indicates that this is theEDM approximation of the Findley tress. Byscanning through aU planediameters and! aU dis-tances :from the center line, the point in the interi-or of the tooth with maximum Findley stress canbe determined.

    Comparison with FEM resultsThe total tooth force as a function 'of contact

    force diameter is determined by the gear compu-tation program LDP (Ref. 8). F(dy) is then approx.-imated by a fourth-order, least- quare fit to thecalculated tooth force.

    In order to, verify the engineering designmethod. a comparison with an FE-analysis wasconducted. Since an evaluation of the CIRF fordifferent gear geometries is already made ill theparameter study, it i possible to make a compari-son for different geometries and parameter combi-nations, The previously conducted FE-analysishas shown that the area inthe interior of the toothwith the highest Findley stresses is close to thecase-core boundary (i,e, at depth CD). ]n theanalysis, dceo:rv= 1.2 mm and .~ = 0.000833 areused. In Figure ll,Bi compari on of the CIRF cal-culated with. the engineering design method(CIRF _EDM)and the CIRF according the FE-computations (ClRF~FE) in the parameter studyis shown,

    Wtis clear fmm Figure I] 'that the overallcor-relation between the CIRF calculated by the EDMand by FEM i good. It i noticed that the EDMovere timates the CIRF. The average discrepancyfor all 32 investigated parameter configurations isH % and never greater than 2'()%.

    DiscussionThe FE-analysis howedthat the hypothesis of

    TIFF presented in this paper was strengthened.The parameter study surprisingly showed that the

    when it comes to gear design. When optimizinggears for noise, usually the slenderness ratio isincreased, since slender gears allow hlgher contactratio andpotentially more silent gears. Therefore,TIFF has to be considered as a possible failuremode in future gear design.

    'Conctusions[II this work, tlIe gear tooth failure mode1FF

    is described and analyzed. In the analysi FE-computatinnsare utilized in conjunction with theFindley critical plane initiation criterion in orderto predict crack initiation. It is shown that theTIFF cracks are initiated in the interior of thetooth. Other results are: The region where the interior crack: will initiateis located approximately mid-height of the toothand slightly below the case-core boundary. TIFF is a possibility at loads lower than. the loadwhere tooth root bending fatigue is achieved andat loads higher than the load where contact fatigueoccurs. By usingthe gear wheel as an idler instead. of asa single stage gear, the risk ofTlFF is increased by20%.

    A parameter study was conductedin order toinvestigate which geometric and material parame-ters influenced! the risk of .WIFf. The parameterstudy was performed as a factorial design. The keyresults from the study are: The parameters influencing the risk of TIFFmostly are 0eril in the interior, the slenderness ratioand the tooth load. The lower the ,oeri!' the moreslender the tooth and the higber the load, thegreater the risk of TIFF. Tbeinfluence from the acp parameter in the inte-rior is small. but positive, meaning the higher theacp' the greater the risk of TIFF. The influence of the carburizing depth on HFF

    NOYEI!!I!!ERIDECEMB'ER 2000 :23

  • Appendix-Gear data for gears in the factorial design.

    Thelgear datal at the two, Igear designs in the, factorial designl are givenintbe table below. fGrc'ompaliison.thegea r d'a.hllofthe 0rigina'i design 'ofthegear is given in Table,3. A sketch oftlte differem gear designs iis given inFigure, 5,.In Table 4. the' c~ack ,initiationlrisk factors ar,e presented as theywere computed by FEMin the 32 experiments in the factorial design.

    i.ssmall, and the risk of TIFF is lower for a high. car-burizing depth than for a low catburizing depth.

    An engineering design method (EDM) fordesign against TIFF was developed, implementedin MatLab and compared with. the FE-calcl.llationsin the parameter study ..The follnwing results werefound:'. It is possible to estimate the risk of TIFF by theEDM very quickly and with. acceptable accuracy . The EDM overestimates the CIRF in the interiorof the tooth compared to the FE-result by an aver-age of 11%.

    AcknowledgementsThis work: was supporsed by the Swedish

    Research Counei1 for Engineering Science (TFR).Thanks are directed to Arne Larsson at Scania forinvaluable help in the field of gear design and gearmanufacturing. The authors thank: GunnarSttandeU at Scania for encouragement and for thepossibility to present this research, and they alsothank Prof. Soren Andessson at KTH for supportand guidance. 0References1. DIN (Deutsobe Instil!.!1filJ Normung) 3m Teil 3 (1987).Tragfiihigkeitsberechnung \Ion Stimradem.2. AGMA Standard 2003-A86 (1982). AGMA Standard forRating the Pining Resistance and Bending Strength of Spurand Helical Involute Gear Teeth.3. Mackaldener M. and M. Olsson, "Interior FatigueFracture of Gear Teeth," Fatigue Fract. Engng MaJer.Struct . 23. pp, 283-292. 2000.4. MackAldener M. and M. Olsson, "Interior Fatigue inGear Teeth," Proc, of Fa/igue 2{)()(),Eds. M.R. Bache etal.,Cambridge, EMAS, 2000.5. Shulz, M., and J. Salller, Schadenuntersuchungen anZal:mriider, Konferenz. Einzelbericht: RaOOschichtenniidlll1g

    I im Wiilzkontakt, AWT-Tagung,. Arbeitsgemeinscbatt WIinn-1-----"-----+---~.:.::..----+-----"'O.""50""3'---- ......,1 i ebehandlung und Werkstofftechnik, Subl, D, 06.-07. 1992.

    0.353 i 6. Alban, L., E., Systematic A/Wlysis of Gear Failures,American Society for Metals, 1993.

    0.550 7. ANSYS 5.5 Users manual (1998) ANSYS Inc.0.372 8, LDP, Load Distribution Program v10.01. (1997) Ohio-0.317 Stale University.0.224 9. Findley W. N., "A Theory for the Effect of Mean.Stress0.3'1'1, on Fati,gue of Metals Under Combined Torsion and Axial01.251 Load or Bending," J. Ellgn.gfor Industry, November, 1959,01.916 pp. 301-306.

    10.E. P. Box, W. G. HU!lter and J. S, Hunter (1978),0.'695 Statistics for Expenmenters, John Wiley and Sons.1.()66 II. D. C. Montgomery (1997.), Design and Analysis of

    Experiments, Fourth Edition, John Wiley and SOilS.1.2.K. L. Johnson (1993). Contact Mechanics, CambridgeUniversity Press.

    0.7512 0.4493 0.7524 0.4375 0.2066 0..11151 0.203

    9 0.151110 0,44911 0.148

    13 0.20014 0.105'5 0.20316 11.10011 11,72018 11.3801'91 0.180

    21 0.20622 0.10523 0.20324 0.10025 0.'69026 0.430121 0.75028291 0.20630 0,10531 0.20332 O,TOO

    24 GEAR TECHNOLOGY

    0.58611.4170.64610.4290,35810.2590.468

    0.596,0.4320.6810.4760.8390.589

    0.'61'90.428

  • WIform grinding, 01_ 01~ gear manufadur.ing. and g..box rebuild& ~. Her. at caGear,lnc. w. are poisedand ready 10 meet yourgearing needs.We guarantee it.

    On Board Gear CItecIdne On Board 'WfMwI ,DreHing

    c-B Gear" M'achlno, Inc.

    CA'LL TODAY FOR A FRE'E ,QUOTE2811-449..0777 IFAX: 281-890-9127 WWW.CIGEAR.COM,

    'CIRCLE 109

  • Printed withp.erm;s-

    sian of the ,copyright

    holder, the American

    G,earManufacturers

    Association, 1500King

    Street Suite ,20',

    Alexandria, V;~g;nia

    223'4. Copies 01 the

    papel ale svai/able

    from the Association.

    Statements presented

    ;n Ihis pape" are those

    ofthe Author and may

    lIot represent the

    position or opinion of

    the American Gear

    Manufacturers

    Association.,

    Gear Units o',nTraveling Bridge Cranes

    J. M. Escanaverino

    IntroductionBridge cranes Me among the most useful

    machines in many branches of modem industry.Using standard hooks or other specialized damp-ing devices, they can lift, transport, discharge,and stack a variety of loads.

    Gear technology progress has always beeninfluential to advances in bridge crane design,allowing lighter and more productive cranes.Many bevel-helical gear units are employed inthe traveling drives of big industrial bridgecranes, as they form compact packages with cou-plings, brakes and electric motors that other gearunits do not allow for.

    A sketch of a typical individual wheel travel-ing drive is shown in Figure I, with the electricprime mover (a) and the gear unit (b), with IIusualhollow low-speed shaft (c). The gear unit ismounted on a floating base (d), common with theprime mover. All the aggregate pivots are on thelow-speed shaft, which is vertically fixed at theother end to the crane framework by means ofelastic blocks (e). The flexible coupling betweenthe prime mover main shaft and the gear unit i ahigh-speed shaft mat is usually combined with adrum brake (f).

    In a number of cranes, frequent failures oftravel 'bevel gears pose a difficult problem for

    (I)(a)

    (d)

    Fig. I-Typical bridge crane traveling drive.2& GEAR TECHNOLOGY

    maintenance. Open discussions have raised ques-tions about the necessary service or applicationfactor to avoid such failures and the associateddowntime. Recommendations found in pres-tigious sources give application factor valuesfrom as low as 1.1 to ashigh as 3.0. In many gearunit catalogs, the crane traveling drive selectionrefers to the manufacturer, giving no other guid-ance to crane designers or plant maintenanceengineers.

    This paper focuses on the origin of the trou-bles experienced witb the standard, general pur-pose bevel-helical gear units used in the travelingdrives of medium and large size bridge cranes,according to the author's theoretical research andpractical experience.

    Nature or the FailuresFailures of crane traveling drives are usually

    of a 'catastrophic character, with the sudden frac-ture of one or several teeth in the bevel gear, ordi-narily in the high-speed stage in the gear unit.

    The above-mentioned failures are very diffi-cult to anticipate, because time between failures(Ref. 2) behaves chaotically. Sometimes the gearworks well for a relatively long period, in theorder of several weeks, and sometimes the gearbreaks down after a few minutes of work,

    Such an irregular pattern of failure is usuallyassociated with mechanical resonance. But even adetailed analysis of the bevel gear vibrationbehavior in crane bridge traveling gear units gen-erally shows no resonance at all in the gear mesh.This fact may be highly misleading to an engi-neering researcher trying to. find theorigin of theabove-mentioned troubles,

    However, the bevel gear mesh is not the saleelastoinertial system related to the high-speedstage of tbe gear unit. Most important, accordingto our findings, is the elastoinertial system com-prised of gear unit's high-speed shaft and half-coupling, including the brake drum (Fig. 2) ..Forthe sake of brevity, (fie elastoinertiat system con-

  • stiruted by the gear una's high-speed shaft. andltaJf-collpli,ng with. brake drumi . referred to fromnow on as the haft/coupling ystem,

    to fact. almost. all ofthe torsional elastic com-pliances of the haft/coupling system belong to,the shaft. This is because of the much biggerdiameterand shorter axjallellglh of the ha1f~COI:I-plingand its attached brake drum. Therefore, itcan be easily shown that

    Where,csh is the shaft' elastic compliance.che is the half-coupling's elastic compliance.

    All elastic compliances in (1) and after are givenin radl(Nm), according to the InternationalSystem of units. S1.

    On the other aand.al~ost aU of the momentsof inertia of the s:haftlcoupling system relative toits rotational axis belong to the half-coupling andits attached brake drum. This i.s due to the verysmall diameter of 'the haft as compared with thebrake drum. There~o;e, it can be easily hownthat

    Is '" l,dj + IIIe lilc (2)Where

    1mis the shaft's momenr of inertia.file islhe Ilalf-()oupling's moment of inertia.

    All moments of inertia in '(2) and after are given.in kg.m2, according to the Intematienal System ofunits, 51.

    Being an elastoinertial system with. almostlumped (concentrated) parameters, includingollly one elastic element and only one inertial. ele-ment,the main proper frequency fE of theshaft/coupling syst m can be assessed by thewell-known expression

    1~ 1f.E = 211: ... -c-. -1-, I

    Proper fiieql.lency in (3) and after is given in Hz,accol'dimg to the International System of units, S1.

    The resistive torque at the gear unit's high-speed pinien (Fig. 2) has a pulsation with a fre-quency equal to the me b frequency of the highspeed gear, given by the relation

    Whe:reI'Im is prime mover' rotational! frequency.zp is high peed pinion' number of teeth.

    Both mesh and rotational frequencies in (4) andafter are given in Hz. according to tileInternational System of units. SI. Meanwhile. the!lumber of teeth i considered non-dimensional

    (1)

    High-Speed Shaft,

    H.alf-Coupling with Brake :Drum

    Fig. 2-ElastoinertiDl s,!slem ,comprised of (II I!igl,-speed shaft ,and haJf-coupling.

    3.50

    3.00

    2.50

    .:22.00

    1.50

    1.00

    0.50

    0.000.00 0.50 LOCI

    Nz.1.50 2.00

    (3)

    .Fig.~Apptkmiofl factor foT' ,a bevel gear.

    Under the excitation of the pul ating piniontorque, the shaft/coupling system d velop 'Ior-sional vibrations, which are uperimpo ed on theotherwise smooth velocitypr'Oft1e of the gear unithigh-speed shaft. The severity of such torslenalvibration is higher when 'the mesh frequency ofthe bevel gear approaches. the proper frequency oflite shaft/coupling system.

    The degree of mutual approach of the abovementioned frequencies governing the vibratoryprocess can be quantified by 'the tuning factor,given by 'lbe relation

    fN =--.:::.LZ iE

    The tuning factor in (5) and after is a non-dimen-sional quantity, as long as both frequencies aregiven in the same units,

    According to widely recognized practice (Ref ..3, 6),. an dasto:inertial system i .in at state of re 0-

    (5)

    nance u 0,. Ellg. JoseMartinezIEscanallerinoi.s a g ar consultam and aprof~s or ill thedepartment of engineeringas rh~lnstituto SuperiorPoW nico Jose An/onioEch~trri6 (ISPJAi!}.

    (6)

    As the traveling drive operates under variablespeed, the tuning factor of the sh.afucoupl ing sys-tem sweeps a range of values. According to thecommandgjven by the crane operator, the tuningfactor staya stochastically in one or another value HO\i(JM, Cuba.

    NOVE~BfI!IOECEMBE'R 20~O 27'

  • during a certain time.iff enough time is spent under condition (6),

    the amplitude of the pulsating t.orque can reachhigh values. Such high values can develop lowcycle volumetric fatigue damage on the teeth ofthe bevel geM, leading to its quick fracture.

    The overload imposed by the resonance effectcan be expressed (RJefs. 2, 3, 5) by means of anapplication factor

    IKA. '" -;=========

    O-N1P+[Where

    ~.is the factor of viscous damping.

    The factor of viscous damping in (7) andafter is given in (N'm)lHz, according to theInternational System of units, SI. The applica-tion factor, as it is well known, is a non-dimen-sional magnitnde,

    There isa moderate degree of viscous dampingduetooil film in th.egear mesh androlling bear-ings, as well as from the internal friction of theelastomeric element in the coupling. Therefore,critical damping in the shaft/coupling system isassumed. Such condition. is the ~imitbetween lightand heavy viscous damping ..Critical damping ispresent when relation (8),holds

    =

    The values of the application factor KA. underthe assumption (8) are plotted as a function ofthe tuning factor in Figure 3. It is interesting to

    1.80.

    1.60

    1.40.

    1.20.

    :1{IO.

    ,~0.80

    0.60

    0.00 - =0.00 0.50 1.00

    Nz1.50 2.00

    Fig. 4-Applicalion faclor jor a bevel gelll' with a hydro4YlJll1llicclutch.28, GEAR TiECHHOLOGY

    note that when tbe tuning factor equals unity,the application factor reaches its maximum value

    K A mil'{ = 3.14 ,(9)

    (7)

    That is, the torque transmitted by the bevel pairof the gear unit can reach a value more thantriple the nominal, enough to fracture its teeth ifno. ample streogth has been left.

    In conformiry with this result, the servicefactor of 3.0 according to AGMA 60l0-F97(Ref, I) appears adequate even when resonanceis present Therefore, to dimension a bridgetraveling gear unit fora bulletproof quick:design, or for an emergency overhaul, a servicefactor with the value of 3.0 could be used, butobviouslyat a cost.

    On the lnftuence of Motor ControlleesMany of the failures in the high-speed bevel

    gears of crane bridge traveling drives appearedafter the advent of the solid-state variable speedcontrollers far the electric prime mover'S. Thesecontrollers yield an almost constant torque atthe prime mover main shaft during the startingperiod, suppressingthe strong saw-tooth torqueripple characteristic of the prime movers underthe older magnetic controllers.

    AppaJ'ently, a number of crane designersshortly after being acquainted with the newhigh-technology motor controllers, began todiscard the old hydrodynamic clutches (the so-caned hydraulic couplings) from the travelingdrives of new design as an unnecessary piece ofhardware. Consequently, the connection be-tween prime mover and gear umt was effectedby means of a simple flexible coupling, normal-ly combined with a drum brake.

    However, no flexible coupling bas the strongviscous damping characteristic of hydrodynam-ic clutches, which do. not allow for high valuesof resonance loads .. Let the increase in viscousdamping of the elastoinertial system due to theintrnduction of a hydrodynamic clutch beesti-mated conservatively as twofold. Then, asFigure 4 shows, the maximum value of the cor-responding application factor will be under 1.7,

    This result can justify the service factorsfrom ].5 to' 2.0 given by certain manufacturersfor bridge travel gear units, presupposingtheuse of hydraulic clutches. However. many timesvery similar values are recommended withoutany other necessary condition.

    Therefore, to avoid unexpected problems, itis suggested that the replacement of hydraulicclutches with ordinary flexible couplings in dri-ves with modern motor controllers should be

    (8)

  • undertaken ,only ,after 3) dynamic analysis of theshaft/coupling :system.

    Suggestions to ManufacturersAGMA standards poin.t to the application

    engineer as responsible for an overall systemdesign that avoids operation at resonance.Neverthelessvgear unit manufacturers can abotake some basic measures to avoid near :reso-nance operation of speed reducers 'equippedwith standard drum brakes tIiIatare typical ofcrane traveling bridge drives.

    There are two cemplementary cbaracteristics:in a non resonant-prone gear unit for crane trav-el drives: Minimum elastic compliance of thepmion shaft and minimum mesh frequency of'!.he'bevel gear.

    Both characterisecs tend to decrease thevalue 'of the application factor as given by (7),.Ashorter and 'oversize diameter high-speed shaft.allowed by an improved bearing design, seemsIto be a practical. way to attain, thefirst charac-sen tic. A high-speed pinion with a smallerDUmber of teeth, allowed by a special design ofthe bevel gear, seems to achieve Ithe secondcharacterislic.

    Solutions for Existing SystemsOn the user side, tile instaUation of Ilew gear

    units with a 3,.0 service factor may be too costlyand beyond the possibilities of existing traveldrive sysl,em:s without a major overhaul.However, there are three complementary modifi.-cations rhat can be done to an existing cranetravel drive to improve its resonance behavior:W.Minimize the compliance ofthe pinion shaft.2. Mjnimize the mesh frequency of the bevel gear.3. Minimize the moment of inertia of the high-speed shatt half-coupling.

    AU three modificatien tend to decrease thevalue of the application factor as gilven by (7),..The first and second modification can beachieved by the same ways suggested iill the for-mer cction,at onlya fraction of the co t of atnew gear unit. To minimize the moment of iner-tia of the sha:ft/coupling system. a simple solu-tion is to invert the flexible coupling, as shownin Figure 5. This way, thehigh-speed shaft ofthe gear unit receives the smaUer half-coupling(a), with a. minimum moment. of inertia, as itlack. Ithe brake drum (b).

    A PracticaEExampleA major industrial enterprise in Soutll

    America has two, special-purpose travelingbridge cranes, each with a total mas-s of W65tons, working around-the-clock in a pit-furnacebuilding. The bridge traveling drives for the

    'Illble I-Dynamic: data of Ole origlJUd driva..----,

    ~ramet.er II VII'I f!,----------------------+-------------------.-----------'I 2_1lI.Q-~ radt(N-m)!

    IE 178 Hz0., from II 'to 20 Hz

    Z, II

    fz from II to 220 HzN from 0 10' 1.24..Kit. from I 10,3.'14

    2

    lovemd

    ---=- ,

    .Fig. ~lnven;ion ~fjlexiblecoll-pling.mdividual motoring wheels of each crane werecomposed as follows:1. A slip ring Ale induction electric motor witha nominal power of 25 kW at a ri>tational fre-quencyof [9 Hz (1,[40 min-I), under an oper-ating regime S3 25%.2. A solid-stateelectronic controller forlhe elee-tric motor, which regulates speed and torquethrough stator tension and rotor resistance.3. A bevel-helical three- uage gear u~t, with anominal ratio of W:71. and a main stage centerdistance of 200' mm,4. A flexible coupling between motor and gear'unjt combined with a drum brake. The gear unit.bill-coupling carried the brake dRJm.

    TliIecrane designers selected these gear unitsusing a service factor of t5, as proposed in the

    NO\l,EIoIBER/DECEIoIB'ER 2000 :29

  • Table 2-Dynamic data or Utemodified drives.I

    Panunttel"! VlIlueIF--~~~--~:~~~--------T--------------~~;;'~~~'-~;~)---------------. I. I 7.54 1(".3 kgm2

    III

    I"II,t

    483 Hz

    from 0 to 20 Hz

    9

    from 0 to 180 Hz

    from 0 10 0.373

    from I 10 1.15

    technical catalog of the manufacturer. However,justa few weeksafter plant start-up, there wereserious troubles with broken teeth in the high-speed stages of the gear units. Time betweenfailures ranged tocha:sticaUy from 15 days to [5minutes. It made no difference if spare partscame from the original. equipment manufactureror from other source .

    After a eries of attempts by differentexpert. the problem remained unsolved. Thecrane manufacturer proposed new gear unitssized according to a 3.0 ervice factor. Theauthor was subsequenUy caned-in by the com-pany as an independent advisor.

    Under author's counsel. in-depth researchinto the dynamic of the original drives was per-formed. The most important results are given inTable L The meth ds and techniques used inthis research are described above.

    As can be seen in Table 1. the sbaftlcouplingsystem of the original gear units operated weltdeep in the conventional resonance zone, whichcovered no more than 24% of all the operatingrange of travel speeds .. Consequently, the bevelgear received strong loads. up to 3.14 times thenominal, according to an unpredictable programthat led to tooth fractures after a short period oftime. The solution had a five-point strategy asfollow:1. A new bevel. gear pair was designed and man-ufactured. with fewer teeth in the pinion, tolower the mesh frequency.2. An optimum pinion designallowed a biggerdiameter shaft 1.0 increase the system's properfrequency.3.. The brake drum was transferred to the motorshaft to increase the system's proper frequency.4. The [lew bevel gear pair desig-n was optimizedfor durability and strengtll (Refs. 4. 5,. 7) usingthe same materials and within the same space.5. A stronger taper roller bearing support lor the

    30' ~E"'R TEC>lNOLOQY

    high-speed p.inion was devised to tit the samegear unit case without any change.

    The dy-namic data of the modified shaftlcou-pling system are found in Table 2, which showsthat due to the reduction of the mesh frequencyand the sharp elevation of the proper frequency,the tuning factor now covers a much smallerrange. Therefore, the maximum value of theapplication factor has fallen to only 1.15.

    Thanks to the reengineered high-speed state,the former high rate of bevel gear failures wentto zero. Tbis was accomplished at 20% of thecost of new, biggergear units ized to operatewith a 3.0 service factor. Now. after four yearsof field experience, tile solntionhas proved itseffectiveness.O

    ReferencesI. ANSIIAGMA 601O-p.n. Standard for Spur; Helical.Herringbone and Belief Enclosed Drives.2. Alexander, J. E. and 1. M. Bailey. Systems EngineeringMatlu!mo,tics. Prentice-Hall, Englewood Cliffs, New Jersey,1962.3. H. A. Rothllan. Ed. Mechanical Design and SystemsHandbook. McGraw-Hill. New York:. 1964.4.. Johnson, R. e. Mechanical .Dtsign Synllu!sis. Van

    'ostrand, New Y:ork, 1971.5. Kern, G. A. and T. M. Korn. Malht1lUl/icai Handbook.McGraw-Hili, New York. 1.968.6. ISO 6336. Calculation of load capacity of spur and heli-co/gears.7. ANSIIAGM_A 2003-A86. Ra/ing the Pitting Resistanceand Bending Strength of Gel!erared Slralght Bevel. ZEROLBeveland SpiraJ Bevel Gear Turh.

    'MUs .. v..........If YOU found this al1icJe of inlIrIlt ancf/fK: .....pIell8a1reMm

    If you did not care for thlalr1icle, ..

    If you would Ib 10 reapond tD 11111or any ...de inthll ediIionof,..~,.....fa_response to the IIIInIItIn of CheI'III CGaper. ......editor, at 847-G7-f18t1.

  • _------------IIINDUSTRVNEWS-------------

    Gleason Technical .suppul'l' Cenln', [ti~ v/, ME

    GlleasonOpens NewTech SupportICenter

    Gleason Corporation has announcedthe opening of its new technical supportcenter at 46850 Magellan Drive. Novi,Michigan. This facility will bring anarray of gear manufacturing supportservices '10 cu tomers in lhe Michiganand Western Ohio regions,

    The new facility place many gearmanufacturing solutions and ervices inclose proximity to the important Detroitmarketplace, and help ,ensure thatGleason's customers will receive fast,hands-on respon es to their needs.Gleason customer w.ill have increasedlocal acce s to comprehensive trainiogresource ; process and application engi-neering support; tool managementincluding, in some areas, pick-up anddelivery; spare parts inventories and On-site service per onnel to help reducerepair and maintenance downtime.

    West Industries Becomes UnitedGear and Assem'blyInc.

    On September I, 2000,. We tIndustries of Hudson, Wisconsin, aUnited Stars Company, became UnitedGear & Assembly Inc. (UGA), a world-class manufacturer of gears. shafts,assem:blie and heat-treating operations,The company reputation was buill ontheir responsiveness to. customers, satis-fying customer requirements and work-ing successfully within narrow shippingwindows, UGA meets specific marketconditions by util ..izing techniques thatrespond to. customer orders with. zerorejects and zero turn-around.

    UGA has added new facilityimprovement and service availablefrom: a single source. With the ability andexperience for additional value-addedprocesses, UGA is committed to contin-uous improvement with their manufac-turing system and with customers' partsa:mdcomponents. UGA offers a totallyintegrated supply source, including engi-

    [leering, machining. heat-treating .. plat-ing. assembly and a quality assurancestructure demanded by the marketplace.

    IEmersonConsolidates GearingBrands Under EPT Operations

    Emerson PowerTransmission (EPI).,of Ithaca, New York,has completed theconsolidation ofEmerson's gearingbrand under the

    EPT organization, Effective SeptemberI., 2000, EFT adds the US Gearmotorbrand of gearing products to its alreadyextensive gearing portfolio. Other brandsinclude: Browning brand helical, beveland planetary speed reducers and gear-motors, and Morse brand worm gearreducers and miter boxes.

    According to Bill Boggess, vicepresident. of strategic planning for EPI,"This will enable the US Motors organi-zation to focusall its efforts on electricmotors, and EPT to focus oa all gearingand other power transmission products.Additionally, it. enables Emerson to pro-vide an enhanced support team to serveall of our gearing customers more effi-ciently,"

    Nations,1Broach &: MachineBecomes N!achi Machining

    Techno:logyNational Broach and Machine Co.,

    the manufacturer of Red Ring prod-UC1S, a world leader ill broaching, gearmanufacturing, mil forming equipmentand tooling. i changing its name toNaehi Machining Technology Co. TheRed Ring trademark will be retained.

    Nachihas worldwide manufacturingfacilities and service support offices withaver 6,800 employees. Beside broachand gear manufacturing tools and equip-ment. Naehi is also known for the manu-facture of specialty steels, cutting tools,robotics, hydraulics. bearings. heat treat-ment equipment and specialty machines.

    National Broach and Machine Co.bas been a part of the Nachi family since199]. Together, Nachi and NationalBroach and Machine share over 140

    years of processing experience for cus-tomer broach and gear manufacturingneeds around the world.

    New Managing DirectorlarSumitomoC-yc:loEurope

    Worldwide power transmi sion spe-cial ist Surmtomo Heavy Industries hasappointed Mike McCalln as managingdirector at its European subsidiary.Sumi.tomo Cydo .Europe. The move isnotable because it is the first lime aEuropean has taken full control ince theJapanese gear giant bought the companyfrom its former German owners in 1993.

    McCann originally joined the com-pany in 1998 as sale and marketingdirector, moving from UK competitor.David Brown Radicon. He takes overfrom Fuminori "Frank" Miyoslli. who isreturning to Japan to take a senior posi-tion in lbkyo after seven successfulyears in Europe and six years previou tothat withlheir American sister companyin Chesapeake, Virginia.

    Odds and EndsAS~ Machinery Company has been

    named me exclusive ales rep for Koreanhobber manufacturer. Jeil HeavyIndustries. Steve K. Peterson i the newVice President of Sales, MidwestRegionv for SU America, Inc. ArtISCorporation has announced a joint ven-ture wi.lli NN Wnc. to manufacture plasticgears and components for office automa-tion equipment and industrial applica-tions in Guadalajara, Mexico. Multi.-Arc and Bernex we coming togetherunder one name: Ionlsond, Ine., whichwill be a provider of PVD and CVDcoating services and equipment 0

    Tell Us WIIIIt You"" ,..

    If you found the.e items of interest and/or Iuseful. plean ctn:1e 314-

    If youdidnot care for these items, chleMI.

    If you would Kite to respond to this or anyother article In this edition of G,IT TechnoIogy. plel.e fax your response to theattention of Randy Stott. managing editor. at847-437-6618 or send e-mail messages topeoplBflgeBrtflchnology.com.

    NOVEMBER/DECEMBER 2000 31

  • CPMllHllighPerf'ormance Too,:1 SteelsExpanding 'the IRangeofPerformance Capability

    + Thmughout his 25 years at Crucible Specialty Metals division, Ken Wojslaw has 'gained aIreputation as "Mr. CPM .the Prince of ,Powder."These days. Ken not only runs our CPM shop,

    Conventional Tool Steel he lisalso overseeingl the' exciting 'expansion of our powder production facilities. scheduled forc: eRIC, ibl. e . .comPletiOnlin2001. Others may attempt to imitate our CPM .but they can't imitate our Ken!Service CentersA Division 0' Crucible Malerlals Corporation

    Crucible ParticleMetallurgy (CPM)

    The CPM processresults in a homogeneousmicrostructure with auniform distribution ofextremely fine carbides,

    CPM Tool Steel

    Ken Wojslaw, *Director CPM Powder Facilities,

    8M

    If you're lookingl for superior wear resistance'. greater toughness, hig'her red hardness, lmprovedmachinability, or more consistent heat treat response, then we've' got a CPM tool steel for you!

    In 1970, longl beiore others even thought about P/Mi tool steels, we began pmduction of CPMsteels at our Specialty Metals division in Syracuse, NY. What a success! Since that time' ourCPM product line' has continually moved towards mom ad\lanoed" more highly alloyed steelswhich offer superior properties as a direct result of the CPM process.

    'CPM High S,peed Steels: In 1976. our CPM Rex 76 (HRC '68-70) revolatioaized the cuttingtool marketwitll the highest combined wear resistance. toughness and red hardness available.Our new CPM R'ex 1211 (HRC 70-72), just released in 119991, again offers the highest combinedwear reslstance, toughness and red hardness now available.

    CPM Tool Steels: In 1978 our CPM 10V set new standards for wear resistance in cold worktoolingl, Today we offer an entire family of "Killer V" high vanadium tool steels including ourCPM 3V,9V,10V,'5V; and stainless 420V; and we've got more' under development.

    Innovative In 1970 and still innovative today, Crucible o,ffersthe widest selection of tool steels available anywhere.

    For the Crucible Service Center nearest you, please call:800..365..1185 or visi.t:www.cruciibleservice.cam

    CIRCLE 135CruobIe. CPM. Re.>. 76, 121, 3v' !Iv, rov. rS\l, 420V slIIlIIgisr/llll(j rrademlrts of Crucible MSlf1dals com.

    http://visi.t:www.cruciibleservice.cam

  • PRODUCTS 1& S,ERVICES IND,EX--------------

    GEM MM!JFACTUIIItIi MACHINEShnI GNr 6Hentiq MlClli ..... M._._.H ..__ ..BnIIcM .. 1IKIIi . ~

    BIniIIIiIt ..ISCII...... 1IKIIi ww .. __ ... .35DIIMIrri .. ~ .....__ ._ .__ ..J5S. CIIIiIII MKIi_ -.li&ur IiriIIHIt IlK... .---- ..&IIr l1li11 .. 1IKIIi1ll. w_ .. n .. _ _ .. _. ..H.nI S. Fi........ ._. __ ...31

    ....... ------ .ItoIiIIIIIKtIIIII. .--_31IlIpICtiOIIlllcllilll..... .._._. __ ..-.31llfllllillllldlillll..-.. ..J1~IIK""" ..IIMHIIri .. MIcItiHL... __ . .. ..11RIck Mil..... II1IIc.a.n.__ ._ .._.__ ._ ..l1..... Mai__... ...JlDati.. IIIc:llillel___. ._._. ...nSpli .. Grildi lhchi __ _ _.._ .J7s,t.. MiUilltl __ .. l1&,I .. RalIi.. 1IIICIIiea- l1T Mac:IIilll.._ ......_._._._._ ..._ _ ......l1n WonII Rm Mill.. 1IKIIi __ ....DIller s.r M.IllhcllrillIIacIIiIIIL....._.JINON-GEM MACHINESc.... ~ Mlclli_ __..JIc.aiIg Toof ........ 1IadIiIIA _ __.._3IEDII Mlchilll.._._ ..__ ._ ..._ _ .. ....3!1fonIliriIIdIn.- ....._._ _ ..__ ..._...3!.... T..... ~. ...1!t.a.L-.. . ._ __ _ __ ..3!IQuencIIing PrIaa. _ _._ _ _ .3!11nM GrWIn..- ... ----.3!IT c..GriIIHrs..... .....J!IT 1IIctIiItn- ........_M...._ ......__ ._w .31DIller NoIt-GtIr 1IIc:IIi1ll.._. __ .__ .n ...l!I

    GEM MAnRIAL$Bar S1Dck.... .._ ..__ ._._ _._ _.Cat ... .__ 41s- ll.u ..__ - __ 4D1'III:dcI.- _ ...__._ .._ ...._._._.PowtItrM Is... __ _ ..... .._ .._._.SIiItII.-- ._. 4D0CMr 1IIIIriI1L._. ._.

    GWSElMCU.... s.-............. 41BrIIIClIiag SIrYiceL_ .._. . ~41CIMIIIti ..... _ ....._._ ..... . .._.1~ __ .__ . 42

    C-GMrY"I1" aCIIIiaI TIOI....,.111 ..... _ --Mfilii AuIyIiI....-- .-hIr tMIap .-GMrDaip ....a.. Eniilllrill- . Mi6Mr .... SIniceL.- IfNIT........... ../aplctill1Inices.......~._ ..._._._._.~ ..__ 4!IStIaC '-ill SInM:IL... ..... ..~__ ..Stod: 6ur Y.IIIfKIIIriII.-----.--...5ITool CoIIiIl-_ ...~. . .._ .510dMtr Slnicll.. .__ .._._._~...._..._. .__..511

    GEM SOfIWAilCIIItM SaftwlnI no._ .52s.r DIIigI SaftwIn __ .._ _ .52GAr IIIspIctiIIIIftwn __...52SIIop Softw _ _ _ 53.,.... SoftwIJI_ n _n 53

    GEM TOOUNG ACCESSOIIIESMrIIha.- _.. _ _ _ _..53InllliHr CIIIIiIt TooIa.. .._._ .. _._ _._ ..53~ _ __ .__ .__ .53BrNcIUItI Tools.... __ __ __ _ ..53c..a... _ _ _ _.53Cllllllwilll TooIL.-._. __ ._. __ .._.53CoIfiIlp.... .._ .. ._.__ __.._ ,53

    CaIIIr BoIIi 54CIIIli", TooII .._ _._ _._ _ __ 54DIIMniII TooIs.-_._ ..__ ._ ..__ _ .._._ ....54DilllOlld WIIeeIL .._ m ~. __._ _ _.54Dreiling Di m _ 54my Taeli Suppli _ __ ..__ _ _ .54Fillrltial Equi _, __ ._ _ _ _-54G lllIIUri .. 11IIInIInInII. _ _54Grillllilll WIiIIIL._. __ __ .._._ _ _ 55IIeIt bdll!ltln-._. __ .._. __ ._._..55HaIIs-__ _ _ __ _._ _ 55IlIdex PlItII. _ .551IIjtcti. Il0l _ ..__ .._. __ _ .55KIJHII ~_. _....55LIppi", CoIIpounda. .._ __ _ _ .55I.Jlllric.IIII/'CooI.IIII.~ _.._ _ .._ _. __ ..55.... s-..._._..__ _. ._.~.55su,. CIIlIrs. __ ....... _ __ ._. __ ._._ _..51Sltaing I:I1II1'1.. __ 09.__ _ 511s,tt.. Rallill RICb . _--YW'HIIlNiJIt DnIIIiIII DIwiceL- --5IWanI Millintl c.n..._.__ _ _.!i&0IHr TooIi.. I AccaHriIL_. _ .._58

    GEAR WORIHOLDING I fIXTVBINGAnon. _ _ _ 51CIHIcks. __ __ -__ _._ _._ .51~.. _. .._._..51,Mad FimrII._. __ __ __ .5I,TooIlIDldIrL_ ..__ ...M._ __.MM_ _._ _.5I0IIIIr ~. FixmriIII-._. __ ._.-._.51

    COMPLETECOMPANYCONTACTINFORMATIONIS AVAILABLEIN THECOMPANY INDEXON PAGES 61-75.

    Welcoml' 10'ilia 20016,'1 ",chnoIOgy BUYln IGuida, IProdQc.IS,& ,SeNlen Ind'elt Usa 11111fillip: to 1iH:ltlIIIe,names, of companin a!:conlinllID lIIal products ,lIId ,..,.vices they providl!'. The cO!!!,plete !!!ai~!!glll!:ddrllSS. plumeand fIX !numben ,Ind e.mail Ind Web lit., Iddnrssu 01'each company lIN IiSIJd in 11'111 Comlllny I d II I,.611.Gil' r'ChIlQlogy,llIYlrlisln LN lhoWll ill boldfacI'Iypt.To find lIIe pI'gl' on whicbtl\eir' adsappm. S.8 '1111,Advenilm In.de.1Ion! page 17.

    Mile WI bUll made ltV,,, ''''Orlto "-_lIrt 'l1\li1)1lIII0'pany' nlll!n I!!Id,l!ddl'lSSn.rt COrred, we Cl!!lllotbe I!.I'!npoDsiblll fOI'8Jra,rs of fact or omission.

    '" your cGmplny Is nollisted and you wDuld lik.I' 10be included in nut rear" dlrectory, IllId 1llIllili tol,p.llpl.1lI111.ttlchnology.com" can 847..a1~. OJ 'In:841-m:-6618,and we will add rou tD 'our IMI'IIIng list.

    IGEARMANUFACTURINGMACHINES:

    Bellel Gear'Gener,lltinglMachinesAmerican MachlIleJY &

    EngineeringBasic Incorporated

    Grou-pThe Gleason WorksGreat I.akes Gear

    TechnologiesKlilIgtblberg SOIlne

    GmbHUebhcn- 'GeM

    TedmoIogy Co,Oerlikon Geartec AGSales ConsultantsSUAmrIiaWMW Machinery

    Broaching lMachines IAmerican Broach &

    Machine Co.American M!lChinery &

    EngineeringAnn Arbor MachineApex Broach &

    Machine Co.RH. Jones Machine &

    GageColooial Tool GroupOankshaft. Machine

    Group, DeIroit Broach

    f~Corp.GenemllBroach &

    EngineeringGreat Lakes Gear

    ThcIrnoJogjesKingsford Broach &

    ToolMiller Industrial

    ServiceNadii M~hining

    ThcbnoIogy Co..

    . The Ohio BAl8dI &Machine Co.

    Oswald Forst GmbHSales Consultants

    , 1)1 Miles Inc,U.S. Broach &

    Machine

    BurnishinglMachinesAcme ManufacturingGreat I~ 'Gear

    TechnologiesHWHearllandM&M Pl'edsioo

    Systems

    ChamferingMachinesAcme ManufacturingAmeri.cm1 Mocltinery &

    EngineerLngAmerican Wera. In!:.B~ic InOOl'pOnlfd

    GroupChwnfennulic Inc.The Gk.>ason WorksGM]Geeat Lakes (leN

    TechnologiesLlebhen- Gear

    TechooIo.gy 0.Mitsubishi Machine

    ToolsNacld l\Iladllning

    ndwoIogy Co.Redin CorporationSchenck TurnerSPF Specialties Ud.S AmericaThyssen DrillunitWMW MlIdJineI:y

    llI'ebuni'ngl M'BchinesACIIiIC Manu.fiK;turingAmeriCl!Il MaclIincry &

    lEogineelingAS] .Madtinery Co.

    NOVE'M8ER:IOe,CEMBE'R 2000 35

  • _-----------PRODUCTS& SE:RVICES IINIDEX Engineering

    ASI Machinery Co.Basic Incorporated

    GroupBevel Gears (India) Pvt.Boum&Koch

    Machine Tool Co.Cole Mfg. Systems. Inc.Ftillows Corp.The Gleaso!! WorksGreat Lakes Gear

    TechnologiesKIingelnberg SOOne

    ~I':I' AmcriaI, u..c.Laser Madllning Inc.Lees Bradner Div. of

    Fayscott Co.Liebherr Gear

    ThdmoIogy Co.Nl!chi Ma.chin.ing

    Technology Co.Oerlikon Gel!rtec AGSUAmerica

    Basic IncorporatedGroup

    Bnrlytic SystemsCharnfermatic Inc.The Gle!!SOn WorksGM:IGreat lakes Gear

    TechnologiesHolroydUebherr Gear

    Thdtnology Co.Mitsubishi Machine

    Tools

    On.Une Senrices,.lnc.I Redin Corporation

    Schenck TurnerSPF Specialties Ltd.SUAmerka

    I Thyssen Drillunit

    Gear CuttingMachInesAble ToolingAmerican Machinery &

    THE PURDYCORPORATION

    ISO 9002 CERTIFIED

    586 Hilliard Street P.O. Box 1898, Manchester, a06045-1898 U.S.A.Telephone: 860 649-0000 .~ax:B60 '645-6293

    Home Page: http://www;purdytransmiss;ons.eomE-Mail: .sales@purdytransmissions .eom

    e1998 TIE PUfiOV COAPOAATlONCIRCllE 125

    .36 GEAR TECHNOLOGY

    Gear GrindingMachinesAmerican Machinery &

    EngineeringASI Madll.nery Co.Basic Incorporated

    GroupBelden Machine Corp.Bluegrass Precision

    Machinery&um&Koch

    Machine Tool Co.Cole Mfg. Systems. Inc.Eltech Inc.The Gleason WorksGrear Lakes Gear

    Technologies01'1 TechnologiesHermes Machine ToolHOfler Maschinenbau.

    'GmbHI Hoglund Technology

    Hulfman CorporationKlIpp T~no.logi~KIingelnberg SOhne

    GmbHLlebberr Gear

    Teclmology Co.Miller Industrial

    ServiceMitsubishi Machine

    ToolsNoclti MacI1iniQg

    ~Co.OeilikoD Geartec AGOkamoto Corp EDMReishauer CorporationSales Consultants

    I SUAmericaWilton MachineryWMW Machinery

    IGear iRollingMachinesFGT Gage & SystemsOreal lakes Gear

    Technologi