Formsprag LCB-200 Backstop for Mine Ventilation Fan
A major industrial fan manufacturer required a cost-effective backstop for a vertical ventilation fan used at an underground mine. The backstop is installed to prevent windmilling (rotation in the wrong direction) due to air flow from the environment while the fan is turned off. Significant damage to the motor and drive belts can occur if the fan is windmilling during startup.
A Formsprag Model LCB-200 fan backstop, with a torque rating of 150 lb.ft. (200 Nm) and a speed range of 0-3600 RPM, was supplied for this 5 ft. blade diameter fan application. The clutch was installed on the fan shaft below the 40" diameter belt drive sheave.
Economical, low-torque LCB Series clutches were designed specifically to prevent problems associated with windmilling in fan applications. The LCB-200 features a compact, easy-to-install design requiring only 1.125" of shaft engagement. Units are lubricated for life and self-actuated with no power or utility required to operate.