Electric motor driven roof ventilator - has system of cooling air guides and auxiliary blades between motor and rotor

摘要

The roof ventilator has a frame (3) supporting an electric motor (9) with its bladed rotor (4) below. The fan shaft (10) in this zone is enclosed by a heat insulating disc (11) with a central air gap (12). This forms a path for cooling air sucked from outside to reach the rotor for discharge sideways. This flow is assisted by an auxiliary rotor with radial blades (14) located above the disc (11). Above this disc is a parallel sheet (19) forming a space (20) housing the auxiliary rotor, with a central opening through which air is drawn downwards. Air is also drawn in through upper guides (16) to pass baffles (17) which directs the cooling air over the motor casing 18).