US Patent 7923871 Electrical machine

The invention relates to an electrical machine (1) having a stator (4) and a rotor (3), with the rotor (3) having a plurality of axially arranged cooling channels (8) and a first (5a) and a second (5b) end face, and a fan unit (6) being arranged adjacent to each end face and comprising at least two 10 fan segments (7), with one fan segment (7) in each case being associated with one cooling channel (8) and being arranged alternately adjacent to the first (5a) and the second (5b) end face, and with the fan segment (7) having at least one air guide channel (7a) and at least one air guide wall (7b).