Air cooling for salient pole electric machine rotors - uses ducts round pole windings inside rotor and serrated shields outside

摘要

A method of constructing a salient pole electric machine rotor to provide efficient air cooling, involves using ducts inside the rotor and serrated shields outside round the pole windings. The construction is suited to large electric machines, typically with water cooled stator windings. The salient poles (1) of a machine rotor are arranged round the perimeter of the rotor, each with its own winding (2) and each separated from the next pole by a non magnetic clamping block (5). The windings are held by serrated cooling shields (3) which allow the passage of cooling air axially along the outside of the rotor, while ducts (10) allow its passage axially along the inside.