Abstract: The machine is designed for traction motors in electrically driven vehicles, for regulable motors for drives in machine tools with CNC and for other servo-drives and generators running into overload duty. It provides reduced mass at increased resistance of the magnets against demagnetization at higher torque overloads. The rotor yoke is divided into parts, which are fixed on the non-magnetic disks. On each two adjacent edges of the parts of the rotor yoke is formed a common mounting pad, on which is located a permanent magnet. The edges of the parts are tapered and between them are formed void spaces with a trapezoidal cross-section with small base near the permanent magnet and with a larger base adjacent to non-magnetic disks. The ratio of the larger base to the small base is greater than 10.