Full definition
A conveyor drive drum is a crucial component at the discharge (head) end of a belt conveyor system. It is responsible for transmitting tractive force from the drive motor or gearbox to the conveyor belt through friction. The drum's diameter typically ranges from 300 mm to 1,500 mm, and this selection is influenced by factors such as belt tension, belt type—especially the minimum bending radius—and the power requirements of the conveyor system. The construction of the drum usually involves a welded steel cylinder featuring integral or bolted stub shafts, which are machined and balanced to ensure smooth operation.
Lagging is an essential feature of the drive drum's surface, as it significantly affects traction. Various types of lagging materials can be used: smooth rubber lagging, which is generally 6-12 mm thick, is suitable for dry conditions; diamond-grooved rubber lagging is the standard choice for most applications because it channels water and increases the coefficient of friction (COF) to approximately 0.35-0.40 compared to 0.25 for bare steel. For more demanding environments, such as wet or abrasive conditions, ceramic lagging provides the highest COF, ranging from 0.40 to 0.45, and options are available from manufacturers like Rema Tip Top and Flexco.
The face width of the drive drum is typically calculated as the belt width plus an additional 50-100 mm to accommodate the belt's lateral movement. According to guidelines set forth in the CEMA 7th Edition and DIN 22101, a crowned drum face is recommended to help center the belt on the drum during operation. Additionally, the shaft must be designed to handle combined bending loads from the belt tension and torsional loads from the transmitted torque. Bearing selection is based on the ISO 281 standard, with an L10 life expectancy greater than 50,000 hours to ensure reliability and longevity in operation.