Varian Associates, Inc.

Paolo Pellizzari

Dario Inserra

Fausto Casaro

Giampaolo Levi

Marco Marzio

A process for manufacturing impellers of turbine pumps provides for subjecting disks corresponding to the impeller to be obtained to electrical discharge machining, using tools in form of plates provided with radial slits extending along at least an arc of circumference and opening into hollow areas. A combined motion of rotation and translation is imparted to the disks, thus generating twisted blades having a profile with defined geometric characteristics. A one-piece rotor can be manufactured employing open tools with slits formed along a semicircumference, and two passages in succession of the workpiece through the tools, moving the workpiece with a combined motion of rotation and translation. An advantageous application of the articles manufactured by this process is for rotors of turbomolecular pumps, since the compression ratio and the pumping speed are optimized and a considerable structural sturdiness of the article is obtained.

Process for manufacturing an impeller by electrical discharge machining

In a stator assembly for a turbomolecular pump, each stator is assembled from two semicircular portions mutually aligned and secured in place by tongue and grooves means, each such stator including a plurality of radially directed blades connecting an inner circular edge and outer circular edge of the stator, such edges occupying respective parallel displaced planes. The outer edge of each stator includes regularly outward projected tabs which bear between spacer rings to maintain axial alignment.

Growing community of inventors

Turin, Italy

Paolo Pellizzari