An active part of an electrical machine includes teeth, each having a tooth base, a tooth height, open or closed grooves between the teeth, and windings introduced into the grooves. Each winding encloses at least one of the teeth. The active part has a thickness, starting from the outer surface of the respective tooth bases and extending along the teeth, that is greater than the tooth height. The active part, starting from the respective tooth base up to a limit depth, which is not more than equal the tooth height, has a first material with a first magnetic permeability and starting from the limit depth a second material with a second magnetic permeability. The first magnetic permeability is greater than the second magnetic permeability. The limit depth is essentially half as great as the tooth height.

One embodiment describes a rotary machine system, which includes a stator with a first tooth, a second tooth, a third tooth, and a fourth tooth; a first electromagnet that includes a first electromagnet wire wrapped around the second tooth and the third tooth and that generates a first magnetic field to attract a drive shaft; a first integrated position sensor, which includes a first sensor wire that carries a first current wrapped around the first tooth and the second tooth; a second integrated sensor, which includes a second sensor wire that carries a second current wrapped around the third tooth and the fourth tooth; and a controller that determines current position of the drive shaft based at least on change of inductance of the first sensor wire and the second sensor wire, and that instructs the first electromagnet to adjust magnitude of the first magnetic field based at least in part on the current position.

There is provided an inductive sensing circuit, comprising a signal generator, configured to generate a drive signal; one or more sensing arrangements, each of the one or more sensing arrangements comprising: two sets of one or more inductive sensing elements, configured in a half bridge arrangement, the two sets of one or more inductive sensing elements driven by the drive signal; a correction signal circuit, configured to generate a correction signal, wherein the correction signal is an adjustably scaled version of the drive signal; and a summing circuit, configured to sum an output signal of the two sets of one or more inductive sensing elements with the correction signal; and a demodulation circuit, configured to demodulate an output of the summing circuit of each of the one or more sensing arrangements.

A bearing arrangement comprising: a first bearing including a first inner race coupled to a rotatable component, a first outer race; and a plurality of first roller elements between the first inner race and the first outer race; a second bearing including a second inner race coupled to the rotatable component, a second outer race, and a plurality of second roller elements between the second inner race and the second outer race; a component, the first outer race being axially moveable relative to the component; and a member between the first bearing and the second bearing and arranged to provide an indirect first force on the first outer race to prevent the first roller elements from skidding when the first bearing and the second bearing receive a second force in a first direction, the second bearing being configured to transfer the second force to the component.

A method of detecting a vibration node between a non-collocated sensor-actuator pair of a rotatable component includes applying an excitation signal to an actuator of the sensor actuator pair. The method also includes obtaining frequency response data from the sensor-actuator pair. The method further includes analyzing the frequency response data to ascertain a resonant frequency of the rotatable component. The method includes identifying a resonance/anti-resonance peak pair in the frequency response data for the non-collocated sensor-actuator pair. Furthermore, the method includes determining whether the vibration node is located between a sensor and the actuator of the non-collocated sensor-actuator pair based on the resonance/anti-resonance peak pair.

An active magnetic bearing apparatus for supporting a rotor of a rotary machine comprises an axial magnetic bearing unit and a radial magnetic bearing unit mounted directly to one another. One of the axial magnetic bearing unit and the radial magnetic bearing unit is mounted to a support for attachment to a housing of the rotary machine.

A flywheel system includes a rotor and a fixture. The rotor forms an aperture. The fixture includes a bottom support, a top support, and a shaft connecting the bottom support to the top support. The shaft passes through the aperture. The bottom support and the top support are outside opposite ends of the aperture. The rotor is configured to rotate about the shaft. A method for operating a flywheel system includes converting between rotational energy of a rotor and electrical energy in windings of a generator stator that is implemented in a stationary shaft passing through an aperture of the rotor, while the rotor is rotating about the shaft.

Flywheel system properties are enhanced with rim designs that control stress at operational rotational velocities. The tensile strength of fiber-resin composites can be aligned with radial forces to improve radial stress loading. Loops with composite casings can be arranged around the flywheel circumference with a majority of the fibers being aligned in the radial direction. The loops can enclose masses that contribute to energy storage in the flywheel system. Masses can be arranged around the hub circumference with a hoop wound composite casing enclosing the masses and hub. The masses subjected to radial forces are radially displaced with increasing rotational velocity and can provide compressive force to the fiber-resin composite to contribute to maintaining composite integrity. With the alignment of fibers in hoop or radial directions, higher loading permits increase rotational velocities, which can significantly add to the amount of energy stored or produced with the flywheel.

A magnetic bearing device comprises a stator (30) and a rotor (10) supported in the stator for rotation around a rotation axis (R). The rotor comprises at least one permanent magnet (21, 22) that is magnetized along the rotation axis. The stator comprises at least one closed magnetic core (31) that surrounds the rotor (10) and at least one radial bearing winding (32) arranged on the closed magnetic core (31) in a toroidal configuration. The at least one radial bearing winding is arranged to interact with a permanent magnetic field generated by the at least one permanent magnet to obtain a radial bearing force when current is supplied to the at least one radial bearing winding.

A magnetic bearing having a colocated eddy-current displacement sensor, comprising an electromagnet unit including a circular casing having a hollow portion therein, and a plurality of electromagnets disposed along an inner periphery of the casing, an amplifier unit coupled to one side of the electromagnet unit, a coil wiring unit coupled to the other side of the electromagnet unit, and a plurality of sensor units disposed along an inner periphery of the electromagnet unit and each having two opposite ends respectively coupled to the coil wiring unit and the amplifier unit, the plurality of sensor units being provided between the coil wiring unit and the amplifier unit, in which the sensor unit is disposed colocatedly with a suspended body supported by the electromagnet unit and configured to measure a displacement of the suspended body.