Axial flow positive displacement worm pump

Abstract: An axial flow positive displacement worm pump has a pump assembly including inner and outer bodies having offset inner and outer axes respectively extending from an inlet to an outlet. At least one of the bodies is rotatable about its axis. The inner and outer bodies have intermeshed inner and outer helical blades wound about the inner and outer axes respectively. The inner and outer helical blades extend radially outwardly and inwardly respectively. One of inner and outer numbers of the inner and outer helical blades respectively is two or more. The number of the outer helical blades is one more or one less than the number of the inner helical blades. The inner and outer bodies may both be rotatable about the inner and outer axes respectively in same inner and outer rotational directions respectively and geared together in a fixed gear ratio. (end of abstract)