Cartridge and block spindles - Gilman USA

Single, 25 hp, CAT 50 integrallymotorizedspindle replaces twobelt-driven spindlesApplicationA major aircraft enginemanufacturer wanted toupgrade the spindle on itsOM-3 and OM-4 SundstrandOmnimills (5-axis machiningcenters with a 150 degreetilting head). Material beingmachined was Inconel, Titaniumand other aerospace alloys.SpindlesNo. 2007Idea bulletinOM-3 and OM-4 SundstrandOmnimills’ spindle upgradeChallengeConverting the originaltwo-spindle arrangement(a low-speed spindle tohandle large tools and ahigh-speed spindle for smalltools) presented a number ofchallenges.A conventional rebuild wouldrequire a completely new slidecasting together with atwo-speed, timing, belt-coupledspindle cartridge requiringoil-bath bearing lubrication,a complicated design thatwould be both hard toadjust and maintain.The rebuilt Omnimillmachine now features asingle, integrally-motorizedGilman spindle that replacedtwo belt-driven spindles.SolutionInstead of redesigning thehead to accommodate aconventional belt-drivenspindle, the machine buildersuggested an integrallymotorizedspindle for betterfunctionality. Ultimately, thesolution came in the form of asingle, 25 hp (18.6 kW) spindlecapable of 7,500 RPM, withCAT 50 taper and throughspindlecoolant.A stock spindle beingunavailable, an Gilman USAengineering team visitedthe rebuilder to review theapplication. After research,the engineers recommendedIndramat windings to fit withinthe severe space constraints ofthe head. A new head castingconfigura-tion, machined toallow coolant to circulate aroundthe spindle body, allowed thespindle to drop into the housingand bolt through a flange,making spindle removal anunder-30-minute job. Toeliminate the problem of ahose band moving with thetilt head, the housing is alsoinner-drilled and plumbed tohandle all hydraulic, coolantand electrical requirements.58 ©2011 Gilman USA, LLC