Electrical motor, with - a shaft on which a rotor is mounted and - a rolling bearing unit by means of which the shaft is mounted rotatably, wherein the inner ring of the rolling bearing is pressed directly onto the shaft, - a rotor support shield, • to which the rolling bearing is fastened, and • which is dimensioned such that it can support the shaft, with the rolling bearing removed, wherein the clearance between the rotor support shield and the shaft is smaller than the air gap between the rotor and the stator of the electrical motor in the operational ready state of the electrical motor, characterized in that the electrical motor is a permanent magnet generator for a wind turbine, and - the rotor support shield seals off a grease chamber of the rolling bearing with respect to the shaft, and - a draw-off device is arranged between the bearing outer ring and the rotor support shield, so that the rolling bearing can be drawn off from the shaft, and - a hub for the rolling bearing is screwed to the rotor support shield, and - the rotor support shield possesses a centering portion which ensures that the shaft with rolling bearing is centered in the rotor support shield when the hub is screwed to the rotor support shield. - a shaft on which a rotor is mounted and - a rolling bearing unit by means of which the shaft is mounted rotatably, wherein the inner ring of the rolling bearing is pressed directly onto the shaft, - a rotor support shield, • to which the rolling bearing is fastened, and • which is dimensioned such that it can support the shaft, with the rolling bearing removed, wherein the clearance between the rotor support shield and the shaft is smaller than the air gap between the rotor and the stator of the electrical motor in the operational ready state of the electrical motor, characterized in that the electrical motor is a permanent magnet generator for a wind turbine, and - the rotor support shield seals off a grease chamber of the rolling bearing with respect to the shaft, and - a draw-off device is arranged between the bearing outer ring and the rotor support shield, so that the rolling bearing can be drawn off from the shaft, and - a hub for the rolling bearing is screwed to the rotor support shield, and - the rotor support shield possesses a centering portion which ensures that the shaft with rolling bearing is centered in the rotor support shield when the hub is screwed to the rotor support shield. • to which the rolling bearing is fastened, and • which is dimensioned such that it can support the shaft, with the rolling bearing removed, wherein the clearance between the rotor support shield and the shaft is smaller than the air gap between the rotor and the stator of the electrical motor in the operational ready state of the electrical motor, characterized in that the electrical motor is a permanent magnet generator for a wind turbine, and - the rotor support shield seals off a grease chamber of the rolling bearing with respect to the shaft, and - a draw-off device is arranged between the bearing outer ring and the rotor support shield, so that the rolling bearing can be drawn off from the shaft, and - a hub for the rolling bearing is screwed to the rotor support shield, and - the rotor support shield possesses a centering portion which ensures that the shaft with rolling bearing is centered in the rotor support shield when the hub is screwed to the rotor support shield. - the rotor support shield seals off a grease chamber of the rolling bearing with respect to the shaft, and - a draw-off device is arranged between the bearing outer ring and the rotor support shield, so that the rolling bearing can be drawn off from the shaft, and - a hub for the rolling bearing is screwed to the rotor support shield, and - the rotor support shield possesses a centering portion which ensures that the shaft with rolling bearing is centered in the rotor support shield when the hub is screwed to the rotor support shield.