Rotary pump for use in e.g. a printing press has two meshing four-lobed rotors which do not contact the inner surface of the rotor chamber

摘要

The rotary pump includes a housing having an inner surface that confines a rotor chamber (31). Two parallel shafts are mounted pivotally on the housing and extend axially through the rotor chamber. Two meshing multi-lobe rotors (41,42) are mounted on the shafts within the rotor chamber, respectively. Each of the rotors has a number of lobes (preferably four) projecting radially from it toward the inner surface without contacting the inner surface.