The invention relates to a wind power generator (1) having a closed inner coolant circuit, having a stator (4) implemented as sheet metal and comprising a winding system forming winding heads (10) at the end faces of the stator, wherein the stator (4) is enclosed by a cooling shell (3) at least in the area of the laminated core thereof, wherein permanent magnets (18) of a rotor (5) are disposed on a magnet wheel shell (6) implemented as a hollow shaft, wherein the magnet wheel shell (6) is rotationally fixed to a shaft or shaft stubs by means of support elements (28) at the end faces thereof, wherein the hollow shaft comprises at least one tube (29, 33)in the interior thereof, the shell surface thereof running equidistant from the magnet wheel shell (6), and wherein blowers (24, 25) are mounted on the end faces of the rotor (5).