Abstract: The present invention relates to a self-priming centrifugal pump which includes a stator case with a delivery port and an outflow port and a radial-centrifugal bladed impeller. An ejector is provided inside the case and has an induction chamber which is connected to the intake port, an entrainment nozzle connected to the internal chamber of the stator case and a diffusion duct which is coaxial to the impeller and is connected to its inflow section. A conveyor is provided after the impeller and includes at least one radial-centripetal conveyance channel and an annular outflow section which extends peripherally to the diffusion duct of the ejector. The conveyor has a configuration which is suitable for directing the flow which leaves the impeller toward a central portion of the case which is adjacent to the outer portion of the diffusion duct and is distant from the delivery port, and for making the flow laminar so as to facilitate the separation of air and its migration toward the delivery port.

Abstract: A case (1) for single- or multi-stage pumps having at least one centrifugal radial impeller, and a method for the manufacture of such case with metal plate. The case includes, for each stage and for each impeller, a substantially cylindrical lateral wall (2) and a device (15) for diffusing and directing the flow delivered from the impeller of each stage, which case has, in the lateral wall thereof, at least one volute with a uniformly increasing transverse cross section which is outwardly closed and is formed by an initial portion (17), an intermediate portion (18) and a final portion (19) which are mutually blended in a continuous manner.

Abstract: A turbopump or the like operating machine driven by a motor includes a casing for the motor having, at one end, a supporting flange for at least one first bearing of the motor shaft and, at the other end, a structure for coupling with a casing of the turbopump. The coupling structure comprises a single coupling flange, which includes a first supporting structure for a fixed sealing element interacting with a movable sealing element associated with the motor shaft and a second supporting structure for at least one second motor shaft bearing. Such first and second supporting structures are rigidly connected to the coupling flange proximate to a central portion thereof and at adjacent positions along the motor shaft.