Positive displacement gear wheel pump - has throughput regulated by plunger varying leakage volume between rotors to return varying percentage of flow to input

摘要

The pump has a casing (5) which contains two rotors (1, 2) each of which is in the form of a gear toothed cylinder. The teeth of the two rotors mesh with each other and carry liquid from one side of the casing to the other. One rotor (1) has a shaft extending through the casing coupled to a motor and drives the other (2) through gears. The rotors fit tightly in the casing except for an area (4) at the ends of the rotors in the region of their engagements where there is a space in the casing allowing oil to leak out of the rotors. The volume of this space is varied by a plunger (3) which by regulating the leakage regulates the pumped throughput.