Abstract: The invention relates to a rotor with a damper for an alternator with projecting poles. The squirrel cage type screen damper, includes not only conventional polar bars (10) sunk in projecting pole pieces (6a, 6b), but also interpolar bars (22) having wings (26) arranged between consecutive projecting pole pieces and ensuring damping of the components of the variable magnetic flux which are of large space pitch. Application to the production of electric power, in particular by submerged hydro-electric bulb units.

Abstract: The invention relates to a gas-cooled rotor for an electric machine. At each axially separated rotor slot, cooling ducts are supplied with cold gas by the duct of a lower cavity and form a parallel network in the upper levels (B) of the slot cavity (1). Said network includes a radial inlet duct (6), a plurality of transverse ducts (8) constituted by grooves in the conductor strips and a radial outlet duct (7) so as to increase the heat exchange surface at these upper levels and to avoid excessive heating thereof despite the heating of the gas in the lower levels (A). Application to turbo alternator rotors.