Patent ID: 8704418

Claim:
An electronically commutated external-rotor motor comprising an internal stator ( 20 ) having a stator lamination stack ( 64 ), a winding arrangement ( 66 ) associated with the latter, and a central opening ( 149 ) defined by the stator lamination stack ( 64 ), in which central opening a bearing tube ( 56 ) is arranged; a permanent-magnet external rotor ( 26 ), separated from the stator lamination stack ( 64 ) by a magnetically effective air gap ( 99 ), which rotor has a shaft ( 42 ) which is journalled in the bearing tube ( 56 ) and to whose region facing toward the external rotor ( 26 ) a hub ( 40 ) is fixedly connected, which hub is equipped, on its side facing toward the internal stator, with an axial projection ( 80 ); two rolling bearings ( 48 , 50 ) arranged at a distance from one another in the bearing tube ( 56 ), namely a first rolling bearing ( 48 ) on an end of the shaft ( 42 ) adjacent the hub ( 40 ), and a second rolling bearing ( 50 ) adjacent another end of the shaft ( 42 ) remote from the hub ( 40 ), which rolling bearings ( 48 , 50 ) each comprise an outer ring and an inner ring, wherein the inner ring of the first rolling bearing ( 48 ) abuts against the axial projection ( 80 ) of the hub ( 40 ), and the outer ring of the second rolling bearing ( 50 ) abuts against a shoulder ( 82 ) formed on an inner surface of the bearing tube ( 58 ), and the shaft ( 42 ) having a free end ( 74 ), the inner ring of the second rolling bearing ( 50 ) being arranged displaceably on the shaft ( 42 ), and means ( 78 ) for applying a spring force, effective between the inner ring of the second rolling bearing ( 50 ) and the free end ( 74 ) of the shaft ( 42 ), which force is adapted to urge said inner ring toward the hub ( 40 ), and the outer ring of the first rolling bearing ( 48 ) being braced by a holding member ( 96 ) against a collar ( 60 ) provided on the bearing tube ( 56 ).