Motor-pump aggregate

Abstract

A motor-pump aggregate whose pump is a glandless centrifugal pump and is intended for use in a nuclear reactor plant has hollow coaxial pump and motor shafts which are sealingly coupled to each other. To this end, the first end portion of the pump shaft extends into the adjacent first end portion of the motor shaft and has an external conical shoulder for engagement with an internal conical seat of the first end portion of the motor shaft. A feather holds the first end portions against rotation relative to one another, and the shoulder is urged against the seat by a pair of threaded connectors one of which is anchored in a disc-shaped member in the region of the second end portion of the motor shaft and the other of which is anchored in the first end portion of the pump shaft. The disc-shaped member and the second end portion of the motor shaft have mating ring gears to ensure accurate and a reproducible centering. The connection between the second end portion of the pump shaft and an impeller is similar to that between the second end portion of the motor shaft and the disc-shaped member except that one of the respective connectors is anchored in a transverse end wall which is inserted into the second end portion of and is welded to the pump shaft.