Axial magnetic bearings that include a primary winding(s) and one or more compensation windings that provide compensation such that operation of the first and/or second primary windings and the compensation windings results in a net magneto-motive force of around zero ampere turns. Current can selectively flow through one or both of the primary windings of an opposing pair of axial magnetic bearings, while current flows through the compensation windings in manner that compensates for the magneto-motive force generated by the primary winding(s). In at least situations in which the number of turns for at least one pair of compensation windings is generally equal to the number of turns of each primary winding, the net magneto-motive force generated by current flowing through a primary winding of one axial magnetic bearing and through the compensation windings of both axial magnetic bearings can generally be zero.

A thrust magnetic bearing device includes: a thrust disc fixed to a rotating body; and a pair of electromagnets provided so as to sandwich the thrust disc and be spaced apart from the thrust disc in a direction along a rotation axis. Each of the pair of electromagnets includes: a coil wound around the rotation axis of the rotating body; and a ring-shaped core accommodating the coil. The core includes a slit which is located at at least one circumferential position of the core and extends from an outside outer peripheral surface as a starting point toward a center of the core. The slit is formed in a range including at least an inside outer peripheral surface.

A magnetic bearing device for magnetically suspending a rotor (22) for rotation about a rotation axis (A) comprises an amplifier device, a first main coil (p) and a second main coil (n). In order to compensate for a stray flux that is created when the main coils are supplied with currents from the amplifier device, a compensation coil (c) is connected between a common node of the main coils and the amplifier device with such polarity that a current flowing through the compensation coil will diminish the stray flux caused by the main coils (p, n).

An advanced substrate rotation device is provided. A substrate rotation device is disclosed. The substrate rotation device includes an outer cylinder, an inner cylinder positioned inside the outer cylinder, a motor for rotating the inner cylinder, a magnetic bearing for magnetically levitating the inner cylinder, and a substrate holder disposed on the inner cylinder. The motor is a radial motor including a motor stator mounted on the outer cylinder, and a motor rotor mounted on the inner cylinder. The magnetic bearing is a radial magnetic bearing including a magnetic bearing stator mounted on the outer cylinder, and a magnetic bearing rotor mounted on the inner cylinder. The magnetic bearing is configured to magnetically levitate the inner cylinder with an attractive force between the magnetic bearing stator and the magnetic bearing rotor.

Disclosed are a magnetic bearing, a compressor and an air conditioner. The magnetic bearing includes a radial stator, wherein the radial stator has a plurality of stator teeth extending inwardly in a radial direction thereof; two axial stators are arranged on two axial sides of the stator teeth, respectively; and radial control coils are wound on the stator teeth, each radial control coil being located outside an area of the stator teeth covered oppositely by the two axial stators. The magnetic bearing, the compressor and the air conditioner can effectively reduce the degree of coupling between a radial electromagnetic control magnetic circuit and an axial electromagnetic control magnetic circuit, and reduce the control difficulty of the magnetic bearing.

A system and method for controlling rotor dynamics at a rotor assembly. The system includes a magnetic actuator and a controller. The magnetic actuator is positioned in magnetic communication with the rotor assembly and is configured to obtain a measurement vector corresponding to the rotor assembly and a measurement vector indicative of a rotor dynamics parameter. The magnetic actuator is further configured to selectively output an electromagnetic force at the rotor assembly. The controller is configured to store and execute instructions. The instructions include outputting, via the magnetic actuator, a baseline electromagnetic force to the rotor assembly; obtaining the measurement vector at the rotor assembly from the magnetic actuator; determining non-synchronous vibrations corresponding to the rotor assembly based at least on the measurement vector and a rotor speed of the rotor assembly; determining cross coupled stiffness corresponding to the rotor assembly based at least on the measurement vector, the rotor speed, and a predetermined rotor dynamics model of the rotor assembly; determining an adjusted electromagnetic force of the rotor assembly based at least on the cross coupled stiffness and a damping factor corresponding to the electromagnetic force output from the magnetic actuator; and generating an output signal corresponding to the adjusted electromagnetic force to the rotor assembly.

Magnetic bearing that is provided with a radial actuator part and an axial actuator part, whereby the aforementioned radial actuator part comprises a laminated stator stack that is provided with a stator yoke, wherein the stator yoke is linked to a closed ferromagnetic structure that surrounds the stator yoke.

A radial stator includes a stator core, and the stator core includes a stator outer ring. M magnetic poles are arranged on an inner circumferential wall of the stator outer ring, and are evenly distributed along the inner circumferential wall of the stator outer ring. The M magnetic poles include M.sub.1 magnetic poles arranged along the inner circumferential wall of the stator outer ring and M.sub.2 magnetic poles arranged along the inner circumferential wall of the stator outer ring; M2, M.sub.11, and M.sub.21; the M.sub.1 magnetic poles and the M.sub.2 magnetic poles are arranged on two sides of the stator outer ring with respect to a radial direction thereof, respectively; each of the M.sub.1 magnetic poles is provided with a first winding; and each of the M.sub.2 magnetic poles is provided with a second winding; and a coil turn N.sub.1 of the first winding is greater or less than a coil turn N.sub.2 of the second winding.

The aim of the invention is to better compensate for specifiable forces on a magnetic mounting. This is achieved by a magnetic mounting device with a first magnet device (10), which is designed in an annular manner and which has a central axis, for retaining a shaft on the central axis in a rotatable manner by means of magnetic forces. The magnetic mounting device additionally has a second magnet device (12), which is independent of the first magnet device (10), for compensating for a specifiable force acting on the shaft. In this manner, the magnetic mounting device can compensate for the gravitational force or forces based on imbalances.

An electromagnetic actuator can exert a radial electromagnetic force on a body that is configured to rotate about a rotational axis. The actuator includes a radial control magnetic pole assembly that includes radial control poles adjacent to and spaced apart by air gaps from the body. The actuator includes a permanent magnet (PM) magnetized along the axis, having one pole in contact with an axial face of the assembly and located proximate to a lateral surface of the body. The PM is magnetically coupled to the body in a non-contact manner resulting in a bias magnetic flux in the air gaps. The actuator includes a control coil around the radial control poles located radially outwards from the PM. Electrical current in the coils generates control magnetic flux in air gaps. The non-uniform net magnetic flux distribution around the body results in a radial electromagnetic force exerted on the body.