CAST IRON COMPONENTS
Every Van der Graaf Drum Motor utilizes cast-iron gear housing and motor flanges. By choosing cast-iron over less expensive cast-aluminum components, the Van der Graaf Drum Motor is able to withstand greater levels of belt tension over typical motorized pulley designs. This translates into an extremely durable and efficient design.
CONSTRUCTION MATERIAL
Drum motors are available in all mild steel and optional all stainless steel construction (including end caps, shell, shafts and junction box).
COOLING
The drum motor is designed with all vital components, such as motor and gear reducer rotating in an oil bath, sealed and isolated from the environment. Temperature generated from the motor and gear reducer is transferred through the oil to the drum or shell and dissipates on the belt.
ELECTRIC MOTORS
All electric windings are manufactured to inverter duty standards with rating of 1600v Corona Inception Voltage (C.I.V.) and Class F insulation 155°C with optional Class H insulation 180°C for applications where high temperature operation is required. The drum motor can be supplied with a variety of voltages, frequencies and phase. This wire allows for the motors to be used in conjunction with variable frequency inverters. The magnet wire itself has the ability of withstanding voltage spikes of 7,700 volts.
HERMETIC SEALING
The drum motor incorporates high quality seals to ensure the integrity of the unit. Seals rotate on a hardened bushing to preserve seal life and extend durability. All Van der Graaf drum motors use a bolt-on design utilizing gaskets or o-rings. Wire connection paths within the unit are window stripped and epoxy impregnated to prevent any oil seepage from the motor to the junction box.
HIGH QUALITY GEARS
Precision AGMA 6 (American Gear Manufacturers Association) gears are high alloy steel, precision cut, hardened and honed teeth reducing noise to minimal decibel levels. Low noise levels contribute to good working conditions and Van der Graaf units exceed OSHA low noise requirements.
INSULATION CLASS
Standard Van der Graaf motors have Class F insulation that allows a motor limiting temperature of 155° C. Class H is optional, which allows for a motor limiting temperature Class of 180° C. By providing a higher insulation Class, the electric motor is able to withstand a higher ambient operating temperature. The drum motor has a 80°C temperature rise.