Abstract: A brushless electric motor has a fluid-tight housing, an internal rotor which is connected to an output shaft, stator plates which are disposed at a radial spacing from the rotor, a coolant delivery line leading into the interior of the housing, and a coolant discharge line leading out of the housing. A control arrangement, which as a function of the rotational speed and torque adjusts the volume flow of the coolant flowing through the interior of the housing, is provided to keep the efficiency of the arrangement as a whole high and to provide an electric motor having high power density.