There are presented various embodiments disclosed in this application, including methods and systems of arranging permanent magnets to switch from a first configuration designed for a first torque output to a second configuration designed for a second torque output.

Methods, systems, and mechanical and electromechanical arrangements for field-weakening of an electric machine that utilizes permanent magnets are disclosed herein. One rotor assembly for an electric motor includes a rotor body that moves with respect to a central axis, the rotor body having a core and a number of permanent magnets that move with the rotor body, and the rotor body also having a number of movable field-weakening magnetic materials that move with respect to the permanent magnets and to the central axis.

A motor (31) includes a stator (313), a rotor (311), and a movable member (315). The stator (313) includes a back yoke (313a) that is annular and a plurality of teeth (313b) that protrude inward in a radial direction from an inner periphery of the back yoke (313a). The rotor (311) is provided on an inner peripheral side of the stator (313). The movable member (315) is a movable member provided along an outer peripheral surface of the back yoke (313a), and changes characteristics of magnetic flux flowing through the back yoke (313a) when the movable member (315) is moved.

A retarder-equipped rotating electrical machine includes a rotor, a stator, and a retarder rotor. The stator has teeth at regular intervals in a circumferential direction. One ends of the teeth are disposed to face the rotor. The retarder rotor has a magnetic member continuously in the circumferential direction. The retarder rotor is disposed to face the other ends of the teeth of the stator and configured to rotate integrally with the rotor. A rotor-to-stator pole piece portion having pole pieces at regular intervals in the circumferential direction is disposed between the rotor and the stator. A stator-to-retarder rotor pole piece portion having pole pieces at regular intervals in the circumferential direction is disposed between the stator and the retarder rotor. Both pole piece portions are moved in the circumferential direction to switch between an operation as a motor or generator and an operation as a retarder.

There are presented various embodiments disclosed in this application, including methods and systems of arranging permanent magnets to switch from a first configuration designed for a first torque output to a second configuration designed for a second torque output.

The present invention relates to an electric machine for an aircraft, comprising a stator and a rotor that is rotationally mobile with respect to the stator, the rotor or the stator comprising a plurality of permanent magnets, the machine comprising a device for demagnetising a permanent magnet, suitable for achieving a temporary increase in the temperature of the permanent magnet, in order to limit, during the temporary increase in temperature, an exciting magnetic flux generated by the permanent magnet. The present invention furthermore relates to an assembly comprising an assembly comprising such an electric machine and a hot-fluid source suitable for delivering hot fluid to the demagnetising device of the electric machine. The hot-fluid source may be a gas stream of a turbine engine.

There are presented various embodiments disclosed in this application, including methods and systems of arranging permanent magnets to switch from a first configuration designed for a first torque output to a second configuration designed for a second torque output.

A fluid turbine has semi-spherical, hollow blades arrayed about a vertical axis, and a passive wildlife-deterrent system using ultraviolet coloration of the rotor blades. The turbine's blade shape reduces drag on a convex side and increases drag on a concave side. Part of the center of the array of rotor blades is open, allowing flow through the center of the array. The spherical form enhances fluid flow through the center of the array and results in rotational force on a downwind blade, and directs fresh air into bypass flow.

A passive magnetic bearing employs eddy currents in a copper core between neodymium annular magnets to support the copper core and an associated rotating shaft. The copper core has an annular flange that is coaxial with a hollow cylinder. The hollow cylinder supports a rotating shaft. An annular iron core is coaxial with and surrounds the annular flange. Annular neodymium magnets surround the upper and lower portions of the hollow cylinder. In some embodiments a touch-down bearing is made up of an upper and a lower bearing race that are spaced away from the upper surface and lower surface of the annular flange. The core rotates over the bearing race(s) until sufficient magnetic flux is generated to support the copper core and hence the shaft. Once spinning, a magnetic field is generated in the copper core.

An axial-flux generator for fluid turbines has a continuously variable generator that is constructed of a pair of rotors that move radially across a stator resulting in varying torque and varying power output. In one embodiment the rotors are normally held proximal to the center of a stator by spring tension. The stator is larger than the normally held position of the rotors. As the angular velocity of the rotors increases, the rotors move radially toward the perimeter of the stator, thus encountering a greater stator surface area providing increased torque, increased power generation and a higher-rated output speed when used with a fluid turbine.