Adjustable speed belt gear motors are space-saving, consistently adjustable drives. In the standard edition the central adjustment is manufactured with a hand wheel. Unlike inverter operation the electric motor power remains constant and the torque increases if the swiftness of the motor drops.

The variable speed gear unit housing has a verified symmetrical Variable Speed Belt Gear Motors Speed Reducer Gearbox design. The adjusting pulleys have a wedge formed symmetrical cross section with low mass. The shape of the pulleys ensures uniform flank pressure and for that reason high power transmission, actually at high belt acceleration.

The effect is optimal control behaviour with uniform distribution of forces and minimal energy consumption.