Patent ID: 6720688
Filing Date: 2004-04-13
Classification: H02K

Abstract:
An electric machine (10; 10â€²) with a rotor (26a, 26b; 26c; 36) which is rotatably mounted in a housing (12) with a rotor shaft (24) which extends beyond the housing, a plurality of electromagnet components (28) which are statically disposed in the housing at uniform angular spacings and spaced from the axis of rotation of the rotor, each with a coil core (32) bearing a coil winding (30) consisting of one or more conductors and with permanent magnets (27) which are disposed at uniform angular spacings and are non-rotatably retained in or on the rotor, these permanent magnets each having a pole face aligned opposite end faces of the coil cores (32) and each having a polarity which is successively reversed in the peripheral direction, wherein the coil cores (32) of the electromagnet components (28) are disposed parallel to the axis of rotation of the rotor shaft (24) in the interior of the housing in such a way that their opposing end faces each lie in two planes which are spaced from one another and extend at right angles to the axis of rotation of the rotor shaft and the ends of the electric conductors which form the coil winding (30) of the individual electromagnet components (28) are interconnected via an electric or electronic control device to form at least two pairs of electrical connections and the rotor has at least two outer armature discs (26a, 26b; 26c) which extend radially to before the end faces of the coil cores and in which the permanent magnets are retained with their pole faces aligned with the respective associated end faces of the coil cores, the radially inner region of the said armature discs being provided with openings (46), wherein in each case pairs of legs, which succeed one another in the peripheral direction, have a free end and are each provided with a pole face of different polarity on the free end facing the coil, of the permanent magnets (27) provided in the two opposing outer armature discs (26a, 26b) are connected to one another in end regions remote from the pole faces by a respective yoke (27a) which encloses the magnetic field and is made from soft or hard magnetic material, wherein the armature discs (26a, 26b) are connected to one another by radially extending walls (38; 38â€²) which form the cavity between the armature discs unto a plurality of chambers (40) which are offset with respect to one another in the peripheral direction and are open towards the electromagnet components (28), and wherein the radially inner openings (46) provided in the armature discs (26a, 26b) each open into the chambers (40) of the rotor;wherein the housing includes end walls (14a, 14b) and a peripheral wall (16) defining an interior which is closed off and sealed against the external atmosphere; and wherein, when the rotor is rotating, a fluid contained within the interior of the housing is forced to flow from first spaces defined between the armature discs (26a, 26b, 26c) and the respective housing end walls (14a, 14b) through the openings (46) and into the chambers (40), and then radially outwardly over the outside and between the electromagnet components (28) and into second spaces defined between outer peripheral boundary faces of the armature discs (26a, 26b) and the peripheral wall (16), and then radially inwardly through the first spaces and back into the openings (46), thereby providing for forced circulatory flow of the fluid in a closed flow path defined by the housing and the rotor and extending through the coil windings.