Abstract: A method for production of a rotor for centrifugal compressor, wherein the said rotor is produced from a monolithic disc, which is provided with a central hole. The method consists of use, within an isolating medium, of at least one first electrode which has polarity opposite the polarity of the rotor, wherein the said first electrode operates starting from the outer diameter of the monolithic disc, in order to produce the blades and the cavities of the said rotor, and wherein the processing takes place with a continuous path, consisting of a first step of roughing, followed by a second step of finishing with a tool which has a shape similar to that of the electrode used for the first roughing step, in order to produce an accurate geometry of the blades.

Abstract: A casing (30) for centrifugal compressors comprises a substantially cylindrical body (31) which is internally hollow and has its own central axis (32). The internal cavity of the casing (30) has an internal central axis (34) substantially coinciding with the axis of rotation of the machine and offset, in a vertical direction, with respect to the central axis (32) of the external surface of the cylindrical body (31) so that the casing (30) has an eccentric shape, having portions of different thickness, so as to create zones where the attachment point for the gas inlet counterflange (35) and outlet counterflange (36) can be formed. The invention also relates to a method for the manufacture of a casing (30) for centrifugal compressors.

Abstract: A method for production of a rotor for centrifugal compressors, wherein the said rotor is produced from a monolithic disc (10), which is provided with a central hole (11). The method consists of use, within an isolating medium, of at least one first electrode which has polarity opposite the polarity of the rotor, wherein the said first electrode operates starting from the outer diameter of the monolithic disc (10), in order to produce the blades (14) and the cavities (13) of the said rotor, and wherein the processing takes place with a continuous path, consisting of a first step of roughing, followed by a second step of finishing with a tool which has a shape similar to that of the electrode used for the first, roughing step, in order to produce an accurate geometry of the blades (14).

Abstract: A casing (30) for centrifugal compressors comprises a substantially cylindrical body (31) which is internally hollow and has its own central axis (32). The internal cavity of the casing (30) has an internal central axis (34) substantially coinciding with the axis of rotation of the machine and offset, in a vertical direction, with respect to the central axis (32) of the external surface of the cylindrical body (31) so that the casing (30) has an eccentric shape, having portions of different thickness, so as to create zones where the attachment point for the gas inlet counterflange (35) and outlet counterflange (36) can be formed. The invention also relates to a method for the manufacture of a casing (30) for centrifugal compressors.