Abstract: An electric drive unit includes an electric motor, an inverter supplying electricity to the motor, a continuous current stage supplying electricity to the inverter, a controller including a modulator for driving the inverter controlled by a first digital signal representing the amplitude of the phase voltages to be applied to the motor and by a second digital signal representing the electrical frequency of the phase voltages. An analogue/digital stage calculates the optimum value of the advance angle (?opt) of the voltage applied to the motor relative to the counter-electromotive force (“CEMF”) as a linear function of the peak value of the phase current and an analogue/digital stage for measuring the angle (100 act) between the voltage applied to the electric motor and the phase current. The controller is programmed for estimating the angle (?act) between the phase current and the CEMF as the difference between ?opt and ?act.

Abstract: In an axial fan (1), equipped with a frame (13), a motor (2) and an impeller (3) whose hub (15) is rotationally driven by the motor (2) and where the hub (15) is cup-shaped, with an end wall (16) and an annular side wall (17) to partially contain the motor (2), the motor (2) protrudes from the hub (15) with its longitudinal end (23) which is supported and laterally surrounded by a crown (12) of the frame (13) and the crown (12) has an annular end strip (21) facing the hub (15) and laterally surrounding an annular end strip (22) of the hub (15) which faces the crown (12).