Formsprag Clutch LCB-200 Backstops for Dragline Ventilation Fans
A leading global fan OEM needed an economical backstop for cooling fans used on a mine dragline. Controlling the temperature inside draglines is a significant challenge. Operating in hot, arid conditions combined with the heat generated from up to 20 various electric drive motors can create dangerously high temperatures. The large fans prevent overheating of personnel and equipment by improving cooling and ventilation.
However, problems occur when the ventilation fans are turned off and air flow from the environment or other fans in the system can back-drive the fans, causing them to rotate in the opposite direction (windmilling). Starting a fan while it is windmilling can damage the motor and reduce the life of the drive system belts.
Formsprag engineers specifically designed the economical, low-torque LCB Series backstop to prevent problems associated with windmilling in fan applications. The Model LCB-200, with a torque rating of 150 lb.ft. (200 Nm) and a speed range of 0-3600 RPM, was the ideal solution for this application. The backstops feature a compact, easy-toinstall design requiring only 1.125" of shaft engagement. Units have a wide operating temperature range of -13 to 194° F (-25 to 90° C), which was important for this hot, dusty mine application. All LCB models are lubricated for life and self-actuated with no power or utility required to operate.