Patent ID: 9022753
Filing Date: 2015-05-05
Classification: F04D,H02K

Abstract:
1. A fan ( 1 ) consisting of an electric external rotor motor ( 2 ) and of a fan wheel ( 4 ), the external rotor motor ( 2 ) consisting of a stator ( 6 ) encapsulated with an insulating material ( 14 ), and of a rotor ( 8 ) carrying the fan wheel ( 4 ) enclosing the stator ( 6 ) in a pot-shaped manner, comprising the rotor ( 8 ) having ventilation openings ( 20 ) in a front wall ( 18 ) and the stator ( 6 ) having projecting fins ( 24 ) on a front area ( 22 ) opposite the ventilation openings that are arranged and distributed circumferentially, wherein a gap ( 34 ) forms a passage between a circumferential rim ( 36 ) of the rotor ( 8 ) opposite the front wall ( 18 ) and a stator carrier ( 38 ) for the cooling air current flowing around the stator ( 6 ) during operation of the fan, wherein all the ventilation openings ( 20 ) have a total opening cross-section whose relationship to the total cross-sectional area of the rotor ( 8 ) is in the range of 10% to 30%.