Clutches/Brakes Information Required Core Diameter = 8 inches Roll Diameter = 24 inches Tension = 40 lb Velocity = 150 fpm How to Size Torque = Tension x Radius = 40(12/12) = 40 lb-ft Maximum clutch rpm = Velocity = π(Core Dia.) 150 π(8/12) = 72 rpm 150 Minimum clutch rpm = π(24/12) = 24 rpm Maximum input rpm* = (maximum clutch rpm) x 1.10 = (72)(1.1) ≈ 79 *we recommend the motor be driven 10% faster than the maximum rollspeed to ensure constant tension in the web x Slip rpm = 40(79-24) = 314 watts Slipwatts = Torque 7 7 Magnetic Particle Clutches & Brakes Use a C-50 Clutch Information Required Tension = 150 lb Motor = 200 rpm Clutch continually energized How to Size Torque = Tension x Radius = 150(6/12) = 75 lb-ft x rpm = 75(200) = 2142 watts Slipwatts = Torque 7 7 But clutch is only slipping half the time watts = 2142 = 1071 2 Use a C-100A Clutch 98 Magnetic Particle Clutches & Brakes