Spiral Grooved Visco-vacuum Pump

Abstract

A spiral grooved vacuum pump which works in the pressure range from 1 to 1000 Pa is studied theoretically and experimentally. The flow in grooves and ridges on the pumping rotor is treated as a slip flow, and Boon and Tal's "Narrow groove theory" developed for viscoseals is used. The theoretical predictions show good agreement with the experimental results. Suggestions are made regarding the choice of design parameters, i.e., aspect ratio, helix angle, clearance parameter and groove-width ratio.