Patent ID: 6023118
Filing Date: 2000-02-08
Classification: H02K

Abstract:
A stator of a single-phase shaded four-pole electric motor, comprising four poles which are substantially shaped like parallelepipeds and are arranged in pairs and side by side along parallel axes, said pairs of poles being arranged mutually opposite with respect to a cylindrical cavity adapted to accommodate a rotor of the electric motor, each pole having a pole shoe whose dimensions and inclination with respect to the axis of the respective pole are such as to allow the pole shoes to form, in a position which is centered with respect to the stator, said cavity for the rotor, mutually closer ends of said four pole shoes being mutually rigidly coupled by two bridges which are parallel to the longitudinal axes of the poles and by two similar bridges arranged transversely to the pairs of poles, so as to provide a rigid coupling of the four poles, a removable prism-shaped core being also provided between each pair of parallel poles and proximate to their most peripheral end, said core being arranged transversely to the poles so as to form a substantially rectangular empty space between said two poles, the two cores and the two opposite bridges which lie transversely to the pole, said empty space being adapted to allow the insertion of a bobbin with an excitation coil on the corresponding core so as to keep only one side of each coil inside the stator and keep the other sides of said coil outside said stator, each pair of said pairs of poles being formed by two different poles, a first one having a notch which is defined in a respective pole shoe and constitutes an auxiliary pole, and a second one having a notch which is defined in the respective pole shoe and extending on an internal side of the pole that faces the first pole, all of said four notches being substantially parallel to the axes of the poles, said two substantially rectangular empty spaces, meant to accommodate the windings, having a rectangular wider portion at the notch of the auxiliary pole defined in the internal side of one of the poles of the pair of poles and substantially parallel to said notch, said spaces being able to accommodate said short-circuited windings in order to form two mutually opposite auxiliary poles of said four auxiliary poles.