Van der Graaf Drum Motors Require No Maintenance

A drum motor is a one-component conveyor drive where the motor, gear drive and all moving parts are enclosed inside the drum. The motor and gears operate in a sealed oil bath ensuring proper lubrication and cooling. With no external motor, gear reducer, sprockets, chain or required chain guard, no external component maintenance is required.

For more than 30 years, Van der Graaf has been the leading manufacturer of drum motors for belt conveyors in material handling and processing applications. The rugged, extreme-duty drum motors are available up to 350 hp and 36-in. diameter, with a variety of lagging options to provide a durable drive with a long service-life. Drum motors have a safe and worry-free design that withstands the harshest conditions and reduced operating costs.

Key features include:

No Maintenance

Completely sealed design – no wear parts or grease points. Robust sealing system prevents contamination. Only an oil change required after 50,000 hours of operation.

Lower Energy Costs

Operate at 96 percent mechanical efficiency resulting in lower operating cost. Energy savings of up to 30 percent compared to conventional exposed-drive conveyors.

Operator Safety

No moving parts outside of the conveyor frame. MSHA/OSHA compliant.


Heavy duty bolt-on construction with cast-iron components; withstands greater levels of belt tension and shock loading compared to typical motorized drives.

Mechanical Seals

All drum motors in this series are equipped with mechanical seals; preventing abrasive materials from penetrating the seals and bearings of the drive.

The company’s Heavy-Duty and Extreme-Duty Drum Motors are built for harsh, abrasive and demanding applications, from aggregate processing to underground mining, ship loading and power generation.

The Heavy-Duty and Extreme-Duty series of drum motors are designed for applications requiring high torque gear reducers and electric motors up to 350 hp. These rugged drum motors feature mechanical seals and VPI electric motor windings that address abrasive and high vibrations encountered in aggregate industries operating under harsh and dusty environments.

Benefits include:

  • Designed and built for the harshest, most demanding applications.
  • Mining-grade, advanced sealing system.
  • Significantly lower operating costs.
  • Increased operator safety – no belts or chains to guard.

Over the past five years, engineers at Van der Graaf have carried extensive research and developed a new internal lubrication system that ensures that all bearing, seals and gears are being lubricated on the Extreme-duty series.

“What we have done in our Extreme Duty series is to optimize the cooling system and optimize the delivery of the clean cool oil onto the bearings and motor windings, which extends the life of the components,” said Matthew Lepp, heavy industry drive specialist, Van der Graaf. “This results in maximum lubrication and eliminates the necessity for the user to manually lubricate the product.”

Stone producers are finding the advantages appealing.

“The biggest advantage we have experienced so far is the fact that there have been nearly zero maintenance issues and great reliability,” said Chris Schuch, production manager at Carmeuse Lime & Stone’s Calcite Operation, which uses the drum motors at its plant in Rogers City, Mich. “We installed the Van der Graaf drives and basically have forgotten about them except for recommended checks. This saves us a great deal of time and allows us to utilize our employees for other maintenance and housekeeping around the facility. I will admit at first I was skeptical. But so far I am impressed.”

View original article