A machine having two co-axial and relatively rotatable rotors and a coaxial stator or housing with respect to which both rotors are rotatable is provided wherein two bearing arrangements mutually support the two rotors with respect to each other and with respect to the stator or housing. One of the bearing arrangements comprises multiple support bearings angularly spaced apart with respect to the axis of rotation of the rotors relative to the stator with the support bearings each having an axle or shaft that is fixed relative to one of the rotors or the stator. Each support bearing cooperates with a raceway provided on a concentric adjacent rotor or stator. The machine may be an electromechanical machine such as a wind turbine in which rotational movement of one of the rotors relative to the other and relative to the stator generates electrical energy.

Disclosed in an embodiment are a rotor assembly and a motor including the same, the rotor assembly including: a rotor part; and a first cover including a first fixing plate for covering one side of the rotor part and a plurality of first vane parts protruding from the first fixing plate, wherein a first angle, which is formed by an imaginary line extending from an outer end of each of the first vane parts and a tangential line of a first imaginary circle, is greater than a second angle formed by an imaginary line extending from an inner end of each of the first vane parts and a tangential line of a second imaginary circle, centers of the first imaginary circle and the second imaginary circle are the same as a center of the first fixing plate, the tangential line of the first imaginary circle is a tangential line at a position at which the first imaginary circle and the outer end meet and the tangential line of the second imaginary circle is a tangential line at a position at which the second imaginary circle and the inner end meet.

Disclosed in an embodiment are a rotor assembly and a motor including the same, the rotor assembly including: a rotor part; and a first cover including a first fixing plate for covering one side of the rotor part and a plurality of first vane parts protruding from the first fixing plate, wherein a first angle, which is formed by an imaginary line extending from an outer end of each of the first vane parts and a tangential line of a first imaginary circle, is greater than a second angle formed by an imaginary line extending from an inner end of each of the first vane parts and a tangential line of a second imaginary circle, centers of the first imaginary circle and the second imaginary circle are the same as a center of the first fixing plate, the tangential line of the first imaginary circle is a tangential line at a position at which the first imaginary circle and the outer end meet and the tangential line of the second imaginary circle is a tangential line at a position at which the second imaginary circle and the inner end meet.

An electric motor for high speed operation use and a rotor which enables use of common parts with electric motors for low speed operation use and which thereby enables reduction of the manufacturing costs. The rotor is provided with a shaft, a rotor core which is fastened to the shaft at the outside in the radial direction and has a first end face at one end in the axial direction and a second end face at the other end in the axial direction, a plurality of conductors which are arranged at the rotor core, and a pair of end rings which are respectively arranged adjoining the first end face and the second end face and which short-circuit the plurality of conductors with each other. The shaft has an outer circumference, while the end rings have outer circumferences which are arranged concentrically with respect to the outer circumference of the shaft.

The rotation of the synchronous reluctance motor is controlled through energization of the winding with current of a phase having a ratio k between the total sum of radial-direction widths of the slits on the q-axis and a magnetic gap length, and having a lead angle β from the d-axis. Among the core layers, the radial-direction width, on the q-axis, of the core layer that lies at a position closest in the circumferential direction to a point P at which there intersect the outer periphery of the rotor and the straight line passing through the rotor center and drawn at an angle ψ=arctan(tan β/(1+0.2k)) from the d-axis, is larger than the radial-direction width of other core layers on the q-axis.

The rotation of the synchronous reluctance motor is controlled through energization of the winding with current of a phase having a ratio k between the total sum of radial-direction widths of the slits on the q-axis and a magnetic gap length, and having a lead angle β from the d-axis. Among the core layers, the radial-direction width, on the q-axis, of the core layer that lies at a position closest in the circumferential direction to a point P at which there intersect the outer periphery of the rotor and the straight line passing through the rotor center and drawn at an angle ψ=arctan(tan β/(1+0.2k)) from the d-axis, is larger than the radial-direction width of other core layers on the q-axis.

An axial gap electrical machine employs unique architecture to (1) overcome critical limits in the air gap at high speeds, while maintaining high torque performance at low speeds, while synergistically providing a geometry that withstands meets critical force concentration within these machines, (2) provides arrangements for cooling said machines using either a Pelletier effect or air fins, (3) “windings” that are produced as ribbon or stampings or laminates, that may be in some cases be arranged to optimize conductor and magnetic core density within the machine. Arrangements are also proposed for mounting the machines as wheels of a vehicle, to provide ease of removing and installing said motor.

An illustrative example method of making a magnetic drive component includes inserting a plurality of metal teeth into a metal tube. The teeth respectively have a first portion received against an inner surface of the tube. The teeth respectively have a second portion and a third portion spaced apart and projecting toward a center of the tube. The method includes securing the plurality of teeth to the tube.

An illustrative example method of making a magnetic drive component includes inserting a plurality of metal teeth into a metal tube. The teeth respectively have a first portion received against an inner surface of the tube. The teeth respectively have a second portion and a third portion spaced apart and projecting toward a center of the tube. The method includes securing the plurality of teeth to the tube.

A rotor for a rotary electric machine, wherein: magnet insertion holes are formed, each defined by the plurality of through holes communicating with each other in the axial direction across the plurality of magnetic sheets; and each of the permanent magnets is twisted about the center axis so as to be placed into a corresponding one of the magnet insertion holes, each having opposite ends in the axial direction that are shifted from each other by an angle corresponding to the constant angle, from outside in the axial direction.