Abstract: In a permanent magnet rotor, the circumferential gaps between circumferentially spaced sintered or cast magnets are filled by a plastic or resin material which also coats the outer circumferential surface of the magnets to secure the magnets to the rotor base. The plastic or resin material has a filler of particulate permanent magnet material to thereby provide a more gradual circumferential variation in magnetic flux between circumferentially adjacent magnets.

Abstract: The motor (9) comprises a motor winding with two phases (2, 3). Sensor c detects the orientation of the permanently magnetized rotor. Selector (S) controlled by line (s) which can be connected to a memory (M) selects the sending to circuit (C) of clock pulses (H) or signals (G) coming from circuits (F) which receives the pulses emitted by sensor (c). In circuit (C) the signals received from the selector are processed and shaped into control signals which act in the power stage of circuit (P) upon each of the two phases (2, 3) by triggering and releasing them alternately in such a way as to ensure that the operation of the rotor occurs either in step mode, under the influence of the clock signals (H), or in direct current mode, i.e., as a function of the momentary position of the rotor as it is detected by sensor (c).

Abstract: The winding of the motor comprises coils which may be formed by conductive paths deposited on the surface of an insulating substrate according to the printed circuit technique. Each turn of the coil comprises two active conductors extending radially, inside connections, and outside connections. The outside connections of the outer paths of the coil have a fret or meander shape, constituting three pairs of auxiliary conductor portions. Upon rotation of the rotor, these portions create in the winding induced voltages having a frequency three times the commutation frequency of the coils, the effect of which is to regularize the motor torque.

Abstract: The motor comprises a flexible circuit composed of a substrate disposed in an air gap between the stator and the rotor, bearing a coating of copper etched to produce the various circuit components. Conductive paths carry the current to brushes soldered on zones of the circuit. Another path leads to further zones constituting shorted turns interconnected by striated areas constituting resistor elements.

Abstract: An electromechanical transducer comprises a fixed part and a part rotatable about an axis. One of these parts includes an assembly of aircore coils which are distributed about the axis. Each coil is divided into two parts, each of which comprises two active coil segments intersected by the magnetic field upon rotation of the transducer. The two parts of each coil are furthermore arranged so that the effects of mutual inductance of the active coil segments of one coil part upon the other are reversed relative to the effects of self-inductance in each part.