Abstract: A method for assembling a single-flow turbomolecular vacuum pump and a turbomolecular vacuum pump assembled by a method wherein the pump rotor, rotor shaft, antifriction bearings and motor armature are first assembled to form a unit, balanced outside of the pump casing, and thereafter introduced as a unit into the pump casing and mounted therein.

Abstract: In a displacement machine operating according to the spiral principle and having two displacement elements presenting respective axially interengaging sprial-shaped walls, and drive means connected between the elements to produce a relative translatory circular movement therebetween, an elastic suspension is provided to support at least one of the displacement elements for permitting elastic movement between the elements in a plane perpendicular to the axis of translatory circular movement.In such a displacement machine, whether or not the elastic suspension is provided, the walls of the displacement elements are preferably made, at least at the surfaces contacting one another, of respectively different materials presenting a low mutual coefficient of friction.