SINGLE-FLOW FOUR-STAGE TURBOMOLECULAR PUMP Russian patent published in 2015 - IPC F04D19/04 

FIELD: engines and pumps.

SUBSTANCE: air-gas channel of the turbomolecular vacuum pump includes four series one after another stages: one turbomolecular, one transitional end face molecular and two, the first and the second, cylindrical molecular stages concentrically located opposite to each other. The upper housing is fixed at the end face of the external flange of the middle housing fitted with the cylindrical ledge, through holes, parallel to its longitudinal axis, and the radial hole connecting the injection side of the fourth stage with the system of backing vacuum pumping. The external surface of the cylindrical ledge of the middle housing contains multithread screw grooves with a tilt towards the rotor rotation. The flat face surface of the stator is implemented with the grooves formed by circle arches with the centres evenly located along the central circle, and with a tilt opposite to the rotor rotation and facing with the axial working gap towards the end face surface of the last rotor disk of the turbomolecular stage with the vanes placed along the periphery with inclination towards the shaft rotation. Intervane channels of vanes are optically closed and form a transitional end face molecular stage. Concentrically located opposite to each other equidistant cylindrical sections between the internal surface with multithread screw grooves of the stator and the external surface of the hollow cylinder of the rotor, and also between the internal surface of the hollow cylinder of the rotor and the external surface with multithread grooves of the cylindrical ledge of the middle housing form respectively the first and the second cylindrical molecular stages of air-gas channel of the pump.

EFFECT: improvement of pumping characteristics of the pump and increase of its life cycle.

18 cl, 5 dwg