Basic designs of spring applied electromagnetic release brakes have become standardised in a proven, highly reliable form that is also compact and economic. For example they will have multiple coil springs, a well-
Where the environment is severe, that is hot, cold or wet, changes are needed to the brake materials and enclosure. Electromagnetic spring applied brakes are designed to operate with friction surfaces that are clean and dry. For dockside use an enclosure of IP66 is appropriate, equivalent to resistance to water jets. Also the outer casing of the brakes needs to resist salt water corrosion. A problem area can be the provision of a manual release which allows the brake to be disengaged when power is off. The release mechanism requires two rods to pass through the casing but there are now brake models that achieve this and retain the IP66 enclosure.
Low temperatures also require special brake materials. Wind turbines are a particular environment where extreme temperatures are encountered. A special brake variant called CCV (Cold Climate Version) has been developed to suit a range from -
Where the requirement is increased safety, there are a number of solutions supported by B10 safety data. The B10 rating denotes the number of operations before a 10% failure rate occurs according to DIN EN ISO 13849-
Brakes designed for passenger lifts meet regulations such as TRA200 and EN 81 by mechanical modifications to the basic design. There are models with dual electric circuits and split armature plates that ensure that at least 50% torque is available in the event of a failure. Where this level of decreased torque is a problem, the solution lies in the use of spring applied calliper brakes. Here a number of independent brake callipers act on a rotating steel disc and medium to high torques are possible. As an example, if 5 callipers were used and one failed, the drop in available torque is only 20%. Note that the B10 rating for a pair of spring applied calliper brakes is around 6 million operations, therefore any such failure is unlikely.
Techdrives offer the INTORQ range of spring applied brakes in the UK. These include standard models, brakes with enclosure to IP66, CCV variants and lift brakes.
Standard brake BFK458 with manual release mointoring
Spring applied calliper brake BFK466