braking systems

In tension control applications that have multiple webs or multiple strands, it is very desirable to match the tension of each web or strand. This is most commonly attained by using a closed loop servo control system which controls current to a braking device through the use of dancer arms, follower arms and in-line tension transducers. The problem with such systems is that each web or strand must be individually controlled, increasing the cost and complicating the system with multiple sensors and power supplies.

Magtrol has developed a system to assure that every brake of a given model designation will be matched, at a predetermined torque and current point, to other brakes of the same model designation regardless of material and manufacturing tolerances. Each brake will be matched at the selected match point to within a tolerance of ±1%. The maximum deviation in torque from brake to brake at any point along their torque/current curve (from 0 torque up to the selected matched torque point) will be less than ±4% of the selected matched torque value. With this level of matching, a system with multiple tension rollers would provide tension consistency within ±1% if set at the matched point with all brakes receiving the same current. The matched point can be any value between 50% and 100% of rated torque, which allows the brakes to be optimized for specific applications. Unless otherwise specified, all brakes are matched at 100 rpm.

Typical Brakes vs. Matched Brakes

Matched Brakes

All single Magtrol Hysteresis Brakes can be matched. When ordering, replace the HB in the Hysteresis Brake model number with MHB. For Large Bore Brakes, LB is replaced with MLB.