Patent ID: 7898136
Filing Date: 2011-03-01
Classification: H02K

Abstract:
1. A rotor assembly for an external rotor electric machine, the rotor assembly comprising: a generally cylindrical rotor body including an inner surface and a free end; the rotor body defining a longitudinal rotation axis; at least two permanent magnets longitudinally mounted to the inner surface of the rotor body, at least two spacing elements longitudinally mounted to the inner surface of the rotor body between adjacent permanent magnets; each spacing elements includes a distal end, a proximate end and a longitudinal body between the proximate and distal ends, the at least two spacing elements configured and sized to prevent relative movement of the permanent magnets with respect to the rotor body and made of a non-magnetic material; the longitudinal body has a generally T-shaped cross section defined by a surface abutting narrow portion and a larger portion distanced from the inner surface of the rotor body; the T-shaped cross section configured and sized to receive lateral portions of the permanent magnets between the larger portion and the inner surface of the rotor body.