At the Blommer Chocolate Company's Greenville, Pa. facility, bulk conveyors are used to process nearly two million pounds of cocoa beans every week. The conveyors must operate three shifts a day, six days a week, year round in harsh conditions caused by an abrasive dust used to purify the beans.

'In the early days of this operation, shaft-mounted gearmotor or gearmotor roller chain and the chain safety cover required constant maintenance,' explains Terry Grill, plant engineer.

Blommer switched to low-profile, internally powered drum motors. According to Grill, the company initially chose internally driven drum motors because of the tight quarters in which the conveyors operate. However, the motors offered an unexpected benefit, says Grill -they run continuously requiring little to no maintenance.

The motors include a steel pulley shell crowned to ensure accurate belt tracking and an induction motor coupled to a multistage planetary gear reducer. Output of the gear reducer directly drives the pulley shell. The motors offer high torque and power capabilities because all generated horsepower is used to drive the conveyor.