Roots vacuum pumps model

Construction features and working principle of the pump:

Model ZJ Mechanical Booster Pump, also known as a Roots pump, is a volumetric pump.

Roots vacuum pump employs a pair of rotors, identical and in 8-figure with certain clearance between them in the pump housing, rotating at the same speed in opposite directions to perform function of suction and discharge of gas. The two rotors are supported by rolling bearings in the end covers of the pump, rotating at high speed and are kept at a fixed relative position by a pair of timing gears. The end clearance between rotors and end covers are fixed by adjustable metal shims between the bearing housings and the end cover at the fixed end, which ensures one-direction expansion of the rotor when temperature rises during its operation.

Four sets of inner seals (also known as piston ring) in the two end covers prevent lube oil entering into the pump housing. The shaft seal at the front-end cover, also called as framework oil seal or shaft seal, prevents leakage of air into the pump housing.

In order to reduce temperature of the pump, all models of pumps (expect the two smallest models) are equipped with a gearbox cooler and front-end cover cooler.