Full definition
The drive pulley located at the discharge end of a conveyor system, where the motor and gearbox transmit tractive force to the belt through friction. The head drum is the most critical pulley in the conveyor — it must reliably transmit 100% of the drive force without slipping. Key specifications: diameter (300-1,500 mm, selected per belt tension and minimum bending radius), face width (belt width + 50-100 mm), lagging type (rubber diamond, ceramic, or smooth per drive conditions), crown (0.5-1% of face width for belt centering), and shaft design (combined bending and torsion loads). Per CEMA 7th Edition and DIN 22101. The wrap angle on the head drum (typically 180-240° with a snub pulley) and the lagging friction coefficient together determine the maximum transmittable tension per the Euler equation: T1/T2 = e^(μθ). Dual-drive configurations use two drums in tandem for very high tensions. Shaft bearings: spherical roller or split pillow block, L10 life > 50,000 hours. Brands: Rulmeca, Van Gorp, Lorbrand, Precision Castparts.