Sigma-II Series SGM*H/SGDH USER'S MANUAL - Esco Drives ...

11 Appendix11.1.2 Selection Example for Position Control(9) ResultThe provisionally selected servomotor and SERVOPACK are confirmed to be applicable.The torque diagram is shown below.(N•m)11TorqueSpeed1.730-7.50.11.00.11.511.1.2 Selection Example for Position ControlMechanical SpecificationsLinear motionServomotor1CouplingBall screw• Load speed: V = 15 m/min• Positioning times: n = 40 times/min• Linear motion section mass: M = 80 kg • Positioning distance: = 0.25 m• Ball screw length: L B = 0.8 m• Positioning time: tm = Less than 1.2 s• Ball screw diameter: D B = 0.016 m • Electrical stop accuracy: δ = ± 0.01 mm• Ball screw lead: P B = 0.005 m • Friction coefficient: µ = 0.2• Coupling mass: M C = 0.3 kg • Mechanical efficiency: η = 0.9 (90%)• Coupling outer diameter: D C =0 .03 m(1) Speed Diagram15Speed(m/min)taVtctd1.2tReferencepulseLoadspeedtsTime (s)60 60t = ----- = ----- = 1.5( s)n 40Where ta = td, ts = 0.1 (s)ta = tm − ts −60= 1.2 − 0.1 −60 × 0.25= 0.1 (s)V 15tc = 1.2 – 0.1 – 0.1 × 2 = 0.9( s)(2) Rotation Speed• Load axis rotation speed• Motor shaft rotation speed with direct coupling: Gear ratio 1/R = 1/1Therefore,(3) Load TorqueN = V =15-1= 3000 (min )P B 0.005N = N • R = 3000 × 1 = 3000 (min-1M)9.8µ • M • PT L = B 9.8 × 0.2 × 80 × 0.005= = 0.139 (N•m)2πR • η 2π × 1 × 0.911-4