The Van der Graaf Drum Motor is used to move a conveyor belt. The motor, gear drive and all moving parts are enclosed inside the drum. One advantage of this scheme is that the belt itself serves as a heat sink for motor heat.
MB commented on January 18, 2014
Excellent engineering solution, elegant impressive. M.Banhidi PhD
pyro1955 commented on November 20, 2013
Was the name of this drum motor intentionally mispelled as 'Van der Graaf' rather than "Van de Graaff" as in Robert Van de Graaff the inventor of the moving belt electrostatic generator?