Abstract: A magnetic bearing apparatus capable of correcting inclination of a rotating element with a small magnetic attractive force and capable of stably supporting the rotating element is disclosed. The magnetic bearing apparatus includes: a non-magnetic ring made of non-magnetic material; and at least three axial magnetic poles arranged along a circumferential direction of the non-magnetic ring. Each axial magnetic pole has an arc-shaped coil and a coil housing that accommodates the coil therein. The at least three axial magnetic poles are fixed to the non-magnetic ring.

Abstract: 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.

Abstract: Provided is a canned motor in which vaporization of the handling liquid is reduced in a case where a rotor rotates at high speed. A canned motor 10 includes a stator 18 disposed in a stator chamber 26, a rotor 14 disposed in a rotor chamber 12, and a stator can 7 enclosing the rotor 14. Furthermore, the canned motor 10 includes a stator chamber inlet portion 43 configured such that a cooling liquid for cooling the stator 18 flows into the stator chamber 26, and a stator chamber outlet portion 44 configured such that the cooling liquid flows out from the stator chamber 26.

Abstract: The electromagnet device of the present invention comprises: a yoke having an annular groove in a front surface thereof; an annular coil provided in the groove; and an epoxy resin provided on an outer surface of the coil configured to secure the coil to the yoke, wherein there is a clearance between an outer circumferential surface of the groove in the yoke and the epoxy resin provided on an radially outer side of the coil.

Abstract: A magnetic levitated pump that does not cause pulsation of a pumped liquid and can suppress the generation of particles, which are liable to be produced by contact of a sliding part, is disclosed. The magnetic levitated pump for magnetically levitating an impeller housed in a pump casing includes a motor configured to rotate the impeller, and an electromagnet configured to magnetically support the impeller. The motor and the electromagnet are arranged so as to face each other across the impeller, and the motor is arranged on the opposite side of a suction port of the pump casing.

Abstract: 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.

Abstract: The electromagnet device of the present invention comprises: a yoke having an annular groove in a front surface thereof; an annular coil provided in the groove; and an epoxy resin provided on an outer surface of the coil configured to secure the coil to the yoke, wherein there is a clearance between an outer circumferential surface of the groove in the yoke and the epoxy resin provided on an radially outer side of the coil.

Abstract: A magnetic bearing apparatus for supporting a rotational shaft includes a magnetic bearing, a rotation sensor, a controller which controls an electric current flown to an electromagnet, and at least one vibration sensor. The controller controls the electric current flown to the electromagnet as follows: in a first control mode, a first electric current is flown to the electromagnet for levitating and supporting the rotational shaft; and in a second control mode, a second electric current is flown to the electromagnet in place of the first electric current at a first periodic timing which is detected by the rotation sensor so that vibration is reduced to a lower level than a first vibration value detected in the first control mode in at least one of setting location of the at least one vibration sensor.

Abstract: A magnetic levitated pump that does not cause pulsation of a pumped liquid and can suppress the generation of particles, which are liable to be produced by contact of a sliding part, is disclosed. The magnetic levitated pump for magnetically levitating an impeller housed in a pump casing includes a motor configured to rotate the impeller, and an electromagnet configured to magnetically support the impeller. The motor and the electromagnet are arranged so as to face each other across the impeller, and the motor is arranged on the opposite side of a suction port of the pump casing.

Abstract: A magnetic bearing apparatus for supporting a rotational shaft includes a magnetic bearing, a rotation sensor, a controller which controls an electric current flown to an electromagnet, and at least one vibration sensor. The controller controls the electric current flown to the electromagnet as follows: in a first control mode, a first electric current is flown to the electromagnet for levitating and supporting the rotational shaft; and in a second control mode, a second electric current is flown to the electromagnet in place of the first electric current at a first periodic timing which is detected by the rotation sensor so that vibration is reduced to a lower level than a first vibration value detected in the first control mode in at least one of setting location of the at least one vibration sensor.

Abstract: An oil-free turbo vacuum pump is capable of evacuating gas in a chamber from atmospheric pressure to high vacuum. The turbo vacuum pump includes a pumping section having rotor blades and stator blades which are disposed alternately in a casing, and a main shaft for supporting the rotor blades. A gas bearing is used as a bearing for supporting the main shaft in a thrust direction, spiral grooves are formed in both surfaces of a stationary part of the gas bearing, and the stationary part having the spiral grooves is placed between an upper rotating part and a lower rotating part which are fixed to the main shaft. A thrust magnetic bearing for canceling out a thrust force generated by the differential pressure between a discharge side and an intake side by an evacuation action of the pumping suction is provided.

Abstract: An energy-saving magnetic bearing device with no bias current for making the relation between the excitation current and the magnetic force of the electromagnet linear is provided. In a magnetic bearing device for supporting a rotor 1 serving as the magnetic piece in a levitating state allowing free rotation at a specified position by the magnetic force of a pair of electromagnets 2, 3, the electromagnets 2, 3 are constituted to interpose the rotor 1 and face each other. A driver 204 is a PWM (pulse width modulation) type driver for controlling the excitation current in the electromagnets 2, 3 by modulating the pulse width of a voltage driven at a specified carrier frequency fc, and includes a resonator means for electrically resonating at a frequency equal to the carrier frequency fc.

Abstract: A magnetic bearing apparatus supports a rotating object using magnetic levitation by a magnetic force of electromagnets. The magnetic bearing apparatus includes a PWM driver configured to supply exciting currents to the electromagnets, a driver power source configured to drive the PWM driver, and a displacement error signal removing section configured to extract a displacement error signal of the displacement information from a current flowing through the driver power source and to remove the displacement error signal from the displacement information.

Abstract: An energy-saving magnetic bearing device with no bias current for making the relation between the excitation current and the magnetic force of the electromagnet linear is provided. In a magnetic bearing device for supporting a rotor 1 serving as the magnetic piece in a levitating state allowing free rotation at a specified position by the magnetic force of a pair of electromagnets 2, 3, the electromagnets 2, 3 are constituted to interpose the rotor 1 and face each other. A driver 204 is a PWM (pulse width modulation) type driver for controlling the excitation current in the electromagnets 2, 3 by modulating the pulse width of a voltage driven at a specified carrier frequency fc, and includes a resonator means for electrically resonating at a frequency equal to the carrier frequency fc.

Abstract: An energy-saving magnetic bearing device with no bias current for making the relation between the excitation current and the magnetic force of the electromagnet linear is provided. In a magnetic bearing device for supporting a rotor 1 serving as the magnetic piece in a levitating state allowing free rotation at a specified position by the magnetic force of a pair of electromagnets 2, 3, the electromagnets 2, 3 are constituted to interpose the rotor 1 and face each other. A driver 204 is a PWM (pulse width modulation) type driver for controlling the excitation current in the electromagnets 2, 3 by modulating the pulse width of a voltage driven at a specified carrier frequency fc, and includes a resonator means for electrically resonating at a frequency equal to the carrier frequency fc.

Abstract: An oil-free turbo vacuum pump is capable of evacuating gas in a chamber from atmospheric pressure to high vacuum. The turbo vacuum pump includes a pumping section having rotor blades and stator blades which are disposed alternately in a casing, and a main shaft for supporting the rotor blades. A gas bearing is used as a bearing for supporting the main shaft in a thrust direction, spiral grooves are formed in both surfaces of a stationary part of the gas bearing, and the stationary part having the spiral grooves is placed between an upper rotating part and a lower rotating part which are fixed to the main shaft. A thrust magnetic bearing for canceling out a thrust force generated by the differential pressure between a discharge side and an intake side by an evacuation action of the pumping suction is provided.

Abstract: A magnetic bearing apparatus supports a rotating object using magnetic levitation by a magnetic force of electromagnets. The magnetic bearing apparatus includes a PWM driver configured to supply exciting currents to the electromagnets, a driver power source configured to drive the PWM driver, and a displacement error signal removing section configured to extract a displacement error signal of the displacement information from a current flowing through the driver power source and to remove the displacement error signal from the displacement information.

Abstract: An energy-saving magnetic bearing device with no bias current for making the relation between the excitation current and the magnetic force of the electromagnet linear is provided. In a magnetic bearing device for supporting a rotor 1 serving as the magnetic piece in a levitating state allowing free rotation at a specified position by the magnetic force of a pair of electromagnets 2, 3, the electromagnets 2, 3 are constituted to interpose the rotor 1 and face each other. A driver 204 is a PWM (pulse width modulation) type driver for controlling the excitation current in the electromagnets 2, 3 by modulating the pulse width of a voltage driven at a specified carrier frequency fc, and includes a resonator means for electrically resonating at a frequency equal to the carrier frequency fc.

Abstract: A magnetic bearing apparatus has an electromagnet having a coil for levitating a rotatable member by a magnetic force and a control device to adjust a gain for levitation control of the rotatable member. The control device includes a displacement sensor to detect a levitated position of the rotatable member, a driver to supply a current to the electromagnet, and a phase compensator to adjust the current based on a signal from the displacement sensor. The control device also includes a band-pass filter into which an output signal of the phase compensator is inputted, an amplifier to amplify an output signal of the band-pass filter at a predetermined amplification ratio, and an adder to add an output signal of the amplifier to an output signal of the phase compensator and supply an added signal to the driver. The band-pass filter has a center frequency based on an actual rotation frequency of the rotatable member, a voltage, a current, or a frequency of a power source for a motor.

Abstract: A magnetic bearing apparatus has an electromagnet having a coil for levitating a rotatable member by a magnetic force and a control device to adjust a gain for levitation control of the rotatable member. The control device includes a displacement sensor to detect a levitated position of the rotatable member, a driver to supply a current to the electromagnet, and a phase compensator to adjust the current based on a signal from the displacement sensor. The control device also includes a band-pass filter into which an output signal of the phase compensator is inputted, an amplifier to amplify an output signal of the band-pass filter at a predetermined amplification ratio, and an adder to add an output signal of the amplifier to an output signal of the phase compensator and supply an added signal to the driver. The band-pass filter has a center frequency based on an actual rotation frequency of the rotatable member, a voltage, a current, or a frequency of a power source for a motor.