Examples are:
- blowers and fans of all types
- propellers
- piston engines with delivery into an open pipe circuit
- centrifugal pumps
- stirring apparatus, centrifuges
- vehicles
The mean load torque MLm is roughly one third of the rated torque: Mn/3.
Because the torque M increases quadratically as the speed n increases, the power
P is a function of the cube of the speed. Cutting the speed in half requires only
one eighth of the power.
This relationship is important, for example, in pump and fan motors for heating
and ventilation motors. Instead of reducing the amount of delivery with a slide
valve or throttle valve, it is better to adjust the speed of the drive motor