Techno Linear Motion Catalog10Technical InformationDuty cycle calculationThe RMS (root mean squared) value of a load is oneof the quantities often used to size PT components._____________________L12t1+ L22t2+ ... +Ln2tnLRMS= 3 (11)t1+ t2+ ... tnwhere:LRMS= RMS value of the load which can be in anyunit hp, amp, etc.L1= Load during time period 1L2= Load during time period 2, etc.t1= Duration of time period 1t2= Duration of time period 2, etc.Modulus of elasticityPLE= (12)ADdwhere:E = Modulus of elasticity (lb/in2)P = Axial load (lb)L = Length of object (in)A = Area of object (in2)Dd = Increase in length resulting from axial load (in)Hollow cylinder rotating about its own axis:1WK2= W (R12 + R22)(8)2where:WK2= Moment of inertia (lbft2)W= Weight of object (lb)R1= Outside radius (ft)R2= Inside radius (ft)Material in linear motion with a continuous fixedrelation to a rotational speed, such as a conveyorsystem:VWKL2= W ()2(9)2pNwhere:WKL2= Linear inertia (lbft2)W= Weight of material (lb)V= Linear velocity (fpm)N= Rotational speed of shaft (rpm)Reflected inertia of a load through a speedreduction means gear, chain, or belt system:WKL2WKR2= (10)Rr2where:WKR2= Reflected inertia (lbft2)WKL2= Load inertia (lbft2)Rr= Reduction ratioTimeL1L2L3t13 3t33 33 3t2AxialRadial TangentialCircumferential R1R2