A single-phase synchronous motor comprises a two-pole permanent-magnet rotor (5) between two electromagnetically excited stator coils (9). At the location of the median plane (33) parallel to the direction of magnetization (37) parallel to the direction of the permanent-magnet rotor (5) has a shape which deviates from a cylindrical shape and the dimension of the permanent-magnet rotor (5) in the direction of magnetization (37) is largest near the median plane (33).

The present invention is directed to a flat brushless motor utilizable as a warning in a portable communication device. The center of gravity of the rotor assembly is displaced from the center of rotation so that, by the rotation of the unbalanced rotor assembly, vibrations can be generated and the. By elimination of an eccentric or the like for generating the vibrations, a manufacture in a flat and compact size, as well as a reduction in the number of component parts, can be attained.

A rotor has outside conductors and inside conductors. The outside conductors are connected together at spaced connection points to form an outside loop which is preferably triangular. Each inside conductor has an outer end connected to one of the connection points, and an inner end provided with an output electrical connection. Each outside conductor and the inside conductors connected to its connection points form an inside loop that occupies only a portion of the rotor's circumference. The rotor lies in oppositely oriented magnetic fields which are disposed so that the total magnetic flux through all of the inside conductors varies during rotation, and the total magnetic flux across the outside loop is zero at all times during rotation.

A magnetic bearing arrangement for a rotor, having permanent magnets to absorb radial bearing forces, and having an axial stabilizer which keeps the rotor in a contactless position in relation to the stator. Attached to the stator are electric coils, which interact with magnetizable parts fastened to the rotor. To make the bearing arrangement as independent as possible from the spatial orientation of the rotor axis, and from housing deformations, there is provided, in the vicinity of the rotor center of gravity, a center-of-gravity bearing having a comparatively high radial rigidity and at another point of the rotor there is provided a stabilizer bearing, having a radial rigidity which is less than that of the center-of-gravity bearing. The center-of-gravity bearing supports the major portion of the rotor weight, and the stabilizer bearing is primarily responsible for the static and dynamic stabilization of the entire system.

An electromagnetic transducer is disclosed that is lightweight and has a high power to weight ratio, with the transducer being capable of operation as an efficient motor, alternator or generator, and being particularly useful, for example, in connection with self-propelled vehicle applications such as passenger cars. The electromagnetic transducer can utilize a shell construction, which enhances heat removal, and includes a magnetic-flux producing assembly, having a plurality of spaced magnetic elements, and an armature assembly formed by a winding arrangement of dispersed conductive elements which are separated by flux carrying elements which, to the extent that such flux carrying elements are electrically conductive, are dispersed in one, two, or three dimensions to thus be dispersed-phase flux carrying elements. The armature conductors and flux carrying elements are dispersed to minimize creation of opposing induced currents, or eddy currents, depending on the effect produced on transducer operation. This dispersal enables operation of the transducer at high efficiency with high torque being maintained even during high speed relative motion between the magentic flux producing assembly and the armature with the combination of high torque and high speed producing higher power per unit weight than can now know devices.