Lobe Pumps Applications

Lobe pumps resemble external gear pumps, but have rotors with two, three, or four lobes in place of gears; the two rotors are both driven. Lobe pumps have a more pulsating output than external gear pumps and are less subject to wear. Lobe-type compressors are also used to pump gases; each rotor has two lobes.

Lobe pumps are similar to external gear pumps in operation in that fluid flows around the interior of the casing. Unlike external gear pumps, however, the lobes do not make contact. Lobe contact is prevented by external timing gears located in the gearbox. Pump shaft support bearings are located in the gearbox, and since the bearings are out of the pumped liquid, pressure is limited by bearing location and shaft deflection.