>> P.424
Ⅲ24■CalculationofmarginalaccelerationtimeTorque(thrustforce)requiredfordrivingofprecisionpositioningtablecomestothehighestduringacceleration.Torque(thrustforce)requiredforthisaccelerationislimitedbymotoroutputtorque(linearmotorthrustforce).Therefore,themarginalaccelerationtimewithtableusedhorizontallyiscalculatedbythefollowingequation.ForballscrewdriveandtimingbeltdriveT0:StartingtorqueN・mμ:Frictioncoefficientofrollingguide(0.01)W:Carryingmasskgℓ:Ballscrewleadmr:Pulleypitchradius(0.0159m)η:Efficiency0.9JT:Tableinertiakg・m2JM:Motorinertiakg・m2JC:CouplinginertiaJL:Carryingmassinertiakg・m2N:Numberofrevolutionsofmotormin-1ta:Accelerationtimesg:Gravityacceleration(9.8m/s2)TM:MotoroutputtorqueN・m・orthesteppermotor,itistheoutputtorqueatthenumberofmotorrevolutionsN.・ortheACservomotor,itisthemaximum(momentary)torqueatthenumberofrevolutionsN.k:Factorofsafety(ACservomotor:1.3)(steppermotor:1.5〜2)Wedgereductionratio0.5incaseof1:2:0.25incaseof1:4R0:istancefromthecenterofthetabletothecenterofgravityoftheloadmL:Distancefromthecenterofthetabletotherotatorm●AppliedtorqueTLℓTL=T0+μWg・[N・m]……Ballscrewdrive2πηℓTL=T0+(Wg×Wedgereductionratio)・[N・m]…ApplicabletoTZ2πηrTL=T0+μWg・[N・m]……Timingbeltdriveη●AccelerationtorqueTa2πNTa=(JT+JM+JC+JL)・[N・m]60taℓJL=W・()2[kg・m2]………Ballscrewdrive2πℓJL=W・()2×Wedgereductionratio2[kg・m2]……ApplicabletoTZ2πJL=W・r2[kg・m2]………Timingbeltdrive●TorquerequiredforaccelerationTPTP=TL+Ta[N・m](TP×k<TM)●Marginalaccelerationtimeta2πNkta=(JT+JM+JC+JL)・・[s]60TM-TL[IncaseofAT]●AppliedtorqueTLℓTL=T0+μWg・2πη●CarryingmassinertiaJLℓ・R0JL=W・()22πL●DistancetorotatorLModelℓ[m]L[m]AT120A0.0010.100AT200A0.0010.130AT300A0.0020.186
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