friction clutches - Arten Freios e Embreagens Industriais

Table of Contents◗TENSION CONTROL BRAKESWeb ProductsSTB 600 AND 940 BRAKESSuperior tension control through a broad torque range.Diagram 1: Plumbing the 600/940with no valvesDiagram 2: Plumbing the 600/940with three valvesThe STB 600 and 940 Brakesallow superior torque controlfor your web with Nexen’s lineof patented tension controlbrakes. Three different sizedpiston sets can be actuatedsingly, or in any combinationfor a large number of torqueto-airpressure ranges.This unique design gives youprecise torque control withoutthe problems associated withoperating at low air pressures.Ventilated rotor keepsthe clutch and brake coolThe ventilated rotor creates anairflow path that draws coolerambient air into the center ofthe rotor. The flow path directsair past the interface anddissipates heat radially awayfrom the unit. This keeps theunit running cooler and longerfor better performance.Different piston sizesgive you the widest rangeNexen’s brakes actuate using apiston / diaphragm combinationin three different sizes.There are no o-rings to stick,no seals to drag. There’s nothingto hinder precise control oftorque at lower operating pressures.By engaging and disengagingvarious combinations of small,medium and large piston sets,you’ll have a broad range oftorque vs. Air pressurecombinations. This gives youprecise control over a widerange of torques and airpressures and lets you run awider variety of materials onthe same machine.Features and benefits• Fine torque control forprecise tension control ofweb processes - 500:1tension control range• Field and dynamicprogramming of pressure/torque characteristics forflexible operations• Diaphragm operation — noseals to drag or o-rings tostick for great low pressureperformance• Different size piston sets• Through-shaft mounting• Compact size• No rotary air unionsrequired — eliminates"gun drilling" shaftsVariable torque rangesthrough the use of valvesUse air valves to engage combinationsof pistons as shownin Diagram 2. Read the torquevalue for each piston setdirectly from the Torque vs. AirPressure graph on the nextpage and add them.Example: STB 600Large piston set at 40 p.s.i. hasa rated torque of 95 in-lb.Medium piston set at 40 p.s.i.has a rated torque of 67 in-lb.Small piston set at 40 p.s.i. hasa rated torque of 41 in-lb.Total torque at 40 p.s.i.:Large + Medium =95 + 67 = 162 in-lb.Small only = 41 in-lb.The total torque range of thebrake will equal the sum of thetorques of the individual sets from0 to maximum air pressure.216