Adjustable speed belt gear motors are space-saving, continuously adjustable drives. In the typical version the central adjustment is made with a hands wheel. Unlike inverter operation the engine power remains constant and the torque boosts if the acceleration of the motor drops.
The variable speed gear unit housing includes a tested symmetrical design. The adjusting pulleys have a wedge designed symmetrical cross section with low mass. The shape of the pulleys Variable Speed Belt Gear Motors Speed Reducer Gearbox guarantees uniform flank pressure and 
for that reason high power transmission, also at high belt quickness.
The result is optimal control behaviour with uniform distribution of forces and minimal energy consumption.