A small generator comprising a stator having slots on the inner circumferential surface thereof and generating windings wound on the slots, and a salient-pole type rotor freely rotating inside the stator, in which the stator has a plurality of recesses whose width is essentially the same as the width of openings of the slots and whose area is smaller than the area of the slots, provided at the same intervals as the circumferential intervals of the slots in the vicinity of the opening of the slots; the rotor has circular-arc shaped bulged portions formed outside a shaft hole on the rotor, and crimping portions whose width is smaller than the diameter of a shaft hole provided at the center of the bulged portions; the width of the magnetic path of the rotor winding portion is made more than twice as large as the minimum slot back length of the slots provided on the stator.
A rotor for a rotating electrical machine includes pole faces arranged at locations on either side, respectively, of the rotor D-axis and fins arranged along the rotor Q-axis. The fins increase a section bending moment of inertia along the Q-axis, thereby reducing the need for deep slots in the pole faces extending along the D-axis, resulting in better symmetry of bending stiffness.
A permanent magnet embedded type concentrated winding motor generator, wherein of the mechanically and electrically independent first and second winding groups (4, 5), the plurality of first teeth (2) wound with the first winding groups (4) are divided into three groups (I, II, III) for example, and the winding directions of the windings of adjacent first teeth (2) within the same group (I, II, III) are opposite. Furthermore, one second tooth (3) wound with a second winding group (5) with a different winding specification from the first winding groups (4) is provided between each of the groups (I, II, III). Accordingly, the relative sizes of the generated voltages in the first winding groups (4) and the second winding groups (5) differ each other, allowing the realization of a compact and low cost construction capable of charging two different electric potentials from a single unit, which also enables a reduction in distortion of the waveform of the counter electromotive force, a reduction in iron loss, and an improvement in the efficiency of the motor, and enables the efficient charging of power sources with two different electric potentials.
A rotor in a electrical machine comprises a magnetic core having at least two poles, a plurality of winding assemblies, one for each pole, and a damper winding enclosing at least a portion of the magnetic core and winding assemblies. The damper winding has (i) a plurality of electrically conductive rings concentric with a rotational axis of the magnetic core and (ii) a plurality of bars extending parallel to the rotational axis of the magnetic core and connecting to each of the rings. A radially outward surface of each of the bars is connected to a respective radially inner surface of each of the rings. A spindle of the magnetic core has first and second flat surfaces extending perpendicular to a direct axis of the magnetic core. The magnetic core may include first and second projections extending in opposite directions along the quadrature axis.
