# General functional descriptions

## Eccentric worm-drive pumps

F 550 S, F 550 GS, F 550 TR, F 560 S, F 560 GS, F 560 TR

The eccentric worm-drive pumps F 550 S, F 550 GS, F 550 TR, F 560 S, F 560 GS, F 560 TR are positive displacement pumps. Their worm-shaped rotor (eccentric worm) is eccentrically guided in a stator formed as a counterpart. This results in self-contained cavities during the rotation, in which the medium is smoothly and with low pulsation continuously transferred upwards. The suction side is automatically sealed with the eccentric worm. This allows a high pressure build-up, irrespective of the speed of the motor.