The Drum motor from Van Der Graaf, Shelby Township, Mich. is a one-component conveyor drive with the ac-induction motor, gear drive, and all moving parts enclosed in a rugged drum. The motor and gears operate in a sealed oil bath, ensuring proper lubrication. Heat from the motor and gears also gets transferred through the oil to the drum where it is dissipated by the moving conveyor belt.
There are no external components, reducing maintenance and improving safety. The motor and gearbox are also sealed in the drum, so they can operate in extremely harsh environments. The drum also protects the equipment from high-pressure detergent and water washdowns. The single-unit design saves space as well.
Standard drum motors are available in mild or stainless steel, in nine diameter sizes ranging from 4 to 20 in. The gear housing and motor flanges are cast iron, which lets belt tension be much greater than on conveyor drives with motorized pulleys.
Electric motors are available in voltages and frequency suitable for most applications. The motor range in size from 0.11 to 200 hp, with corresponding belt speeds from 3 to 2,000 fpm. Extreme-duty motors are also available in sizes from 20 to 31.5 in. in diameter, and from 15 to 200 hp. The motors can be specified with an optional electromagnetic brake (for units 4.5 to 16 in. in diameter). The brake can withstand duty cycles of up to 40 stops/min.
See the Drum motor in action and hear more about its performance and construction at EngineeringTV.com