New brake options for cranes & hoists

This has been achieved by new options in the friction material, optimised magnetic circuits and closer manufacturing tolerances. In addition these brakes have IP66 enclosure as standard which suits their target markets of cranes, hoists, winches and wind turbines. The BFK470 range is available for holding torques up to 370Nm.  Brake release is by energising a DC coil with voltage options of 24, 103, 180 and 205 volts.

A main feature of the BFK470 range, and the key to the high performance, is the range of options for the friction material. A distinction is drawn here between ‘normal’ operating duties with frequent dynamic stops, and ‘holding’ duties where brake engagement is usually at zero speed but with occasional dynamic emergency stops.  For normal operation the options of friction material are standard, wear resistant, high temperature resistant or free of running-in. Each has a different friction characteristic and customers can specify a pre-set value in a range approximately -30 to +70% of the normal rated torque. For holding duties a further high coefficient of friction option is available giving torques over two times the normal rating. For example this produces 200Nm from a brake of diameter 200mm.

The high enclosure rating of IP66 suits operation in unprotected outdoor environments including docksides. The brake casings are nitrided steel with internal O rings to seal the joints. Unusually, a manual hand release can be specified without derating the enclosure as special seals are fitted here and to the casing fixing bolts. The high enclosure does not make routine wear checks difficult as there is plug access to measure in the air gap inside the brake. A further option is described as CCV : Cold Climate Variant. This suits ambient temperatures from -40 to +50°C.