Abstract: A method for making a rotating part of plastic material for a permanent magnet motor and a rotor arranged on the outer circumference of the rotating part, said rotor comprising an annular pan (1) and a permanent magnet unit fitted around it, in which method the rotating part is cast in a mold tool (4). The annular part (1) together with the permanent magnets (2) is placed inside a plastic injection mold tool (4), said plastic injection mold tool (4) being divided radially into several sectors (4a-4d) which are provided with slots (6) allowing them to be moved radially by an actuator. When the plastic injection mold tool (4) is being closed, the sector are tightened radially inwards, specifically closing the air gap between the outer surface of the permanent magnet unit (2) and the sectors of the plastic injection mold tool (4), whereupon plastic injection molding is performed.

Abstract: A stator for synchronous motors with more than two poles, comprising a plurality of sectors (10) formed by lamination packs which are joined at their ends (11), forming as a whole a closed annular structure, at least one pole shoe (13) protruding from each one of the sectors (10). The ends of the stator define, at each connecting region (14), thanks to respective facing shaped portions (15), at least one tab (16) with mutually opposite undercuts (17), one for each end, the tabs (16) accommodate corresponding portions of an elastic connecting element (18) which surrounds the tab and rigidly couples the sectors.

Abstract: A cooling system for cooling the components of an electrically driven rotating device, in which system the rotating part (4) of the device produces a current of a medium, such as air, the electric drive consisting of an electric motor (5) for rotating the device and an electronic control unit (6) controlling it, and which cooling system comprises at least one cooling element (62) for cooling the components. The cooling element (62) is disposed near the flow created by the rotating part (4) so that the heat produced by the components can be transmitted either directly and/or via a thermally conductive means to the current of cooling medium (63) created by the rotating device.

Abstract: An air impeller, comprising a frame, a bladed wheel (4) provided with blades (42) for producing a substantially axial flow of a gaseous medium, an alternating-current motor (5) for rotating the bladed wheel, said alternating-current motor comprising a fixed stator (52-54) and a ro-tating rotor, and a frequency converter (6) or inverter for controlling the alternating-current motor, and in which the rotor of the alternating-current motor is integrated with the bladed wheel (4), being placed on its outer rim, and the stator is placed in the frame of the air impeller outside the rotor so that the stator produces rotation of both the rotor and the bladed wheel. The frequency converter (6) or inverter is integrated with the stator or a part of it to form a unitary, frequency-converter or inverter-controlled air im-peller structure.