Spring-applied brakes guaranteed for 10million operations

Spring-applied brakes are widely used for stopping and holding duties. Often a high frequency of operation is required, for example on indexing conveyors, cranes, lifts and hoists.

There are two aspects to the lifetime of the spring applied brake. The first factor is the wear of the brake surfaces due to friction. This is a function of the speed and inertia to be stopped, and the permissible frequency and resulting lifetime can be calculated with reasonable accuracy. Modern friction material such as those used by INTORQ exhibit low rates of wear, particularly if used at low to medium speeds. In addition, the wear can be easily and quickly compensated for by mechanical adjustments without the need to strip down the brake. With inverter- or servo-driven applications, the brake is often applied statically, so friction surface wear is not a limit to the lifetime of the brake.

The second restricting factor on brake life is the mechanical integrity. In each brake cycle there is axial movement of the armature plate, axial movement of the brake disc and rotary forces from the braking friction. Eventually these lead to mechanical wear and require maintenance, which involves a complete strip-down of the brake. INTORQ has countered this problem by adding low-backlash torque supports to the armature, guide pins for the actuating springs, and an insert coating for the axially sliding hub splines. The result is an increase in brake life, which, in a typical application will rise from about 2 to 10million operations.

The new INTORQ BFK458 long-life brakes are available with rated torques up to 32Nm. The big increases in lifetime means big savings in maintenance and downtime. The new design has enabled Lenze and INTORQ to offer a warranty of 10million operations or two years life, whichever is reached first. Follow the link for more information about INTORQ BFK458 brakes.