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.

Provided are a vacuum pump, a magnetic bearing device, and a rotor that suppress swinging and vibration of a rotor. A vacuum pump includes, in the following order in the exhaust direction of a gas, the center of gravity of a rotor, an active radial bearing that supports the rotor in the radial direction in a non-contact manner by using a magnetic force, and a passive radial bearing that supports the rotor in the radial direction in a non-contact manner using a magnetic force.

System for controlling at least one active magnetic bearing equipping a rotating machine comprising a rotor and a stator, at least one means for measuring the radial positions of the rotor as a function of the signal from at least one position sensor, and at least two control loops of the active magnetic bearing as a function of the radial positions of the rotor, each control loop of the magnetic bearing being provided with at least one synchronous filter as a function of the rotation speed, and an extended Kalman filter for determining the rotation speed of the rotor with respect to the stator receiving as input, from position sensors, measurements of radial position of the rotor and as a function of measurements of radial position of the rotor performed over a predetermined time at zero rotor rotation speed.

A magnetic suspension bearing, a magnetic suspension bearing control system and a control method, the magnetic suspension bearing control system includes a processor, a synchronous signal generation module, a displacement signal conversion circuit, a post-processing circuit, an Analog-to-Digital conversion module, a pulse width modulation module, a frequency division circuit, a synchronization module, and a power amplifier. The magnetic suspension bearing includes the magnetic suspension bearing control system, a first iron core, a second iron core, a first and a second magnetic suspension bearing actuator coils wound on the first and the second iron cores respectively, and an electromagnetic force suspension rotor; wherein the first and the second magnetic suspension bearing actuator coils are oppositely disposed on upper and lower sides of the electromagnetic force suspension rotor, and both the first and the second magnetic suspension bearing actuator coils are connected with the magnetic suspension bearing control system.

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 position sensor includes a plurality of E-shaped ferromagnetic cores arranged to define a circular opening therethrough to receive a shaft. Each E-shaped ferromagnetic core has a plurality of teeth, wherein adjacent E-shaped ferromagnetic cores of the arranged plurality of E-shaped ferromagnetic cores have an overlapping tooth. The position sensor further includes a frame surrounding the arranged plurality of E-shaped ferromagnetic cores, with the E-shaped ferromagnetic cores coupled to the frame.

An electromagnet unit in which influence of a noise on a displacement sensor is suppressed and which can be installed in a space-saving manner and a vacuum pump including the electromagnet unit are provided. An electromagnet unit includes a radial electromagnet which controls a shaft to a predetermined position, a radial sensor which detects a position of the shaft, and a printed board interposed between the radial electromagnet and the radial sensor and on which a wiring pattern for sensor connecting coils of the corresponding two radial sensors to each other and a wiring pattern connecting coils of the corresponding two radial electromagnets to each other are provided. The wiring pattern for sensor and the wiring pattern for electromagnet are disposed so as not to overlap when seen from the axial direction.

Disclosed is a method for calibrating at least one gap sensor, the at least one gap sensor being provided on a magnetic bearing supporting a floating body in a non-contact manner by an electromagnetic force, the at least one gap sensor being configured to detect a gap between the floating body and a reference object that serves as a positional reference for position control of the floating body. The method includes: constructing a transformation formula for transforming an output of the at least one gap sensor into the gap using three or more constraints that are set as conditions for associating the gap with the output of the at least one gap sensor.

A magnetic actuator for a magnetic suspension system includes a core section having an annular yoke and radially directed teeth joining the yoke. The magnetic actuator includes coils surrounding the teeth and a mechanical structure having a first section and a second section. The first section is attached to the yoke and conducts magnetic flux axially. The second section joins the first section and conducts the magnetic flux radially in a direction opposite to a direction of the magnetic flux in the teeth. The magnetic actuator includes a mechanical safety bearing that is between the second section and the teeth. Thus, the safety bearing is in a room surrounded by a magnetic flux circulation path. Therefore, the safety bearing does not increase an axial length of the magnetic suspension system.

The present disclosure provides a displacement detection circuit of a maglev rotor system and a displacement self-sensing system thereof. The displacement detection circuit comprises a current sampling circuit (10) configured to collect a current flowing through a corresponding coil (4); coils (4), which are coils (4) distributed in series in the maglev rotor system; Hall sensors (20), the Hall sensors (20) being arranged in an upper auxiliary air gap (8) and a lower auxiliary air gap (8) of the maglev rotor system, and sensing surfaces of the Hall sensors (20) being perpendicular to magnetic field directions in the corresponding auxiliary air gaps (8); a Hall signal processing circuit (30) connected to the Hall sensors (20) and configured to differentiate a Hall sensing signal corresponding to the upper auxiliary air gap (8) and a Hall sensing signal corresponding to the lower auxiliary air gap (8); and a displacement signal resolving circuit (40) connected to the current sampling circuit (10) and the Hall signal processing circuit (30) respectively and configured to acquire a displacement of a rotor in the maglev rotor system according to the current and a differentiation result. By using the detection circuit and the displacement self-sensing system thereof, the axial size of the rotor is reduced, such that detection and control are coplanar, and high precision and simple design are realized.