Non‐contact vacuum pumps

Non‐contact oil‐free vacuum pumps are widely used in different technological processes such as nanomaterials industry, pharmaceuticals industry, food industry, medicine, etc., thanks to absence of oil seal, high discharge, long operating life, yet low energy consumption. Scroll pumps are of particular interest as they make it possible to isolate bearing assemblies with grease from the working volume of the pump with the help of bellows. Pumping characteristics of non‐contact vacuum pumps are greatly influenced by backward leakage through slot channels of the rotor mechanism. The conductance is the main value characterizing backward leakage. In this paper an efficient method for prompt conductance calculation of slot channels with any geometry with the minimal clearance at a certain point along gas flow direction is presented. The calculation error of the presented method does not exceed 6%. The presented method was used in mathematical models for the pumping process of scroll pumps, claw pumps and Roots pumps. This method is recommended for pumping characteristics calculation of different non‐contact pumps and gas flow rates in vacuum systems channels.