Abstract: A predetermined timing is a timing at which the sampling timing is in a vicinity of a maximum peak position of the carrier wave signal and a timing at which the sampling timing is in a vicinity of a minimum peak position. The demodulation arithmetic section outputs, as the demodulation calculated result, a value d3 calculated with d3=(d1?d2)/2 when a data value of the digital signal sampled in the vicinity of the maximum peak position is denoted by d1 and a data value of the digital signal sampled in the vicinity of the minimum peak position is denoted by d2.

Abstract: A magnetic bearing device comprises a controller configured to obtain magnetic levitation information of the rotor shaft by AD sampling of current detection signals from the plurality of current sensors and a sum signal obtained by adding the pair of current detection signals relating to the pair of electromagnets, and perform PWM control of the excitation amplifiers based on the magnetic levitation information. The controller performs PWM control so that a length of one of an on-duty period and an off-duty period of the PWM carrier signal is always longer than a predetermined time period based on an attenuation characteristic of a spike noise produced in the electromagnetic current, and performs the AD sampling after the predetermined time period passes from starting timing of one of the on-duty period and the off-duty period.

Abstract: A motor driving device comprises a first arithmetic section calculating a rotational speed and a magnetic pole electrical angle of a motor rotor, a current command setting section setting a d-axis current command and a q-axis current command in a rotating coordinate dq system based on a difference between the rotational speed and a target rotational speed, a driving command generating section generating a sinusoidal wave driving command based on the d-axis current command, the q-axis current command, the rotational speed and the magnetic pole electrical angle and a PWM signal generating section. When the rotational speed has a positive value indicating a positive rotational state, the current command setting section sets the q-axis current command of acceleration driving, and when the rotational speed has a negative value indicating a reverse rotational state, the current command setting section sets the q-axis current command of deceleration driving.

Abstract: A motor driving device comprises an inverter, a first arithmetic section, a driving command generating section and a PWM signal generating section. The first arithmetic section calculates a rotational speed and a magnetic pole electrical angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current. The first arithmetic section includes a counter electromotive voltage arithmetic section, a converting section, a second arithmetic section, a third arithmetic section, and a fourth arithmetic section. The first arithmetic section outputs a sum of the magnetic pole phase error and the integrated value as the magnetic pole electrical angle.

Abstract: A motor driving device comprises: an inverter having a plurality of switching elements for driving a motor; an arithmetic section for calculating a rotational speed and a magnetic pole electric angle of a motor rotor based on information about a motor phase voltage and information about a motor phase current; a delay correcting section for correcting a phase delay of the magnetic pole electric angle calculated by the arithmetic section so as to generate corrected magnetic pole electric angle; a driving command generating section for generating a sinusoidal wave driving command based on a difference between the rotational speed and a target rotational speed and the corrected magnetic pole electric angle; and a PWM signal generating section for generating a PWM control signal for controlling on/off of the plurality of switching elements based on the sinusoidal wave driving command.

Abstract: A turbomolecular pump having a pump main unit having, at least, a rotary vein provided on a rotor, a static vein for working in cooperation with the rotary vein to perform a vacuum exhaust, and a motor for driving the rotor, comprising: a controlling device that includes a motor driving circuit for converting into thermal energy, in a regenerative braking resistance, the regenerative electric current that is produced at the time of regeneratively driving the motor; and a cooling device for cooling the controlling device. A rod-shape heating resistive element is used as the regenerative braking resistance, where this resistive heating element is routed along the inner peripheral surface of an end portion 14a of the controlling device case that contacts the cooling device.

Abstract: The provision of the components requiring cooling on top of the cooling mechanism enables the cooling efficiency to be increased. Furthermore, a case of a control device is attached to the cooling mechanism whereon the components requiring cooling are disposed. The cooling mechanism fulfills the role of the contact surface of the case of the control device with the turbomolecular pump main unit, where the case does not have a case panel on the contact surface with the turbomolecular pump main unit. The cooling mechanism fulfills the role of one surface of the case for the control device, where the cooling mechanism is structured integrally with the control device. Additionally, the turbomolecular pump main unit, the cooling mechanism, and the control device are structured integrally by the turbomolecular pump main unit and the cooling mechanism being in contact.

Abstract: A condensation sensor is provided within a power supply device that is provided integratedly with a vacuum pump main unit. When the condensation sensor detects condensation within the power supply device, a CPU closes a cooling water valve. This stops the flow of cooling water that flows through the interior of the power supply device, through a cooling water duct.

Abstract: A turbomolecular pump device includes: a turbomolecular pump main body; a power unit that drives the turbomolecular pump main body; and a water cooling unit that is provided between the turbomolecular pump main body and the power unit, wherein components provided in a casing of the power unit are classified into an intensive cooling required component that requires intensive cooling, a moderate cooling required component that requires moderate cooling, and a no cooling required component that requires substantially no cooling, the intensive cooling required component is mounted on a first high-conductivity substrate contacting to the water cooling unit, the moderate cooling required component is mounted on a second high heat-conductive substrate contacting to an inner surface of the casing, and the no cooling required component is mounted on a substrate arranged in a space between the first high heat-conductive substrate and the second high heat-conductive substrate.

Abstract: A vacuum pump capable of accurately detecting a rotor temperature based on a change in permeability of a magnetic material. Two targets are fixed to a nut opposed to a gap sensor. The nut is made of pure iron, and a surface of the nut opposed to the gap sensor serves as a target. The target has a Curie temperature greater than a temperature monitoring range, and each of the targets has a Curie temperature falling within the temperature monitoring range. When the targets become opposed to the gap sensor in turn according to rotation of a rotor, three types of signals are output from the gap sensor. The difference-signal generation means generates a difference signal of each the targets, on the basis of a signal of the target. The difference signal is compared with a reference signal V0 for detecting the Curie temperatures to detect a rotor temperature.

Abstract: A vacuum pump configured to exhaust gas includes an inductance gap sensor positioned oppositely near an end face of a rotational axis of a rotational body including a rotor; a plurality of individually formed recesses disposed at the end face facing the gap sensor at respectively different angular positions; and at least one ferromagnetic body disposed in at least one of the recesses. The ferromagnetic body has a Curie temperature approximately equal to an allowable temperature of the rotor. The gap sensor senses inductance changes associated with changes in magnetic permeability of the ferromagnetic body to detect a temperature of the rotor. One of the recesses where the ferromagnetic body is not disposed is a rotational number sensor target. Thus, a rotational number of the rotor is detected based on a change in inductance when the rotational number sensor target passes opposite the inductance sensor.

Abstract: A condensation sensor is provided within a power supply device that is provided integratedly with a vacuum pump main unit. When the condensation sensor detects condensation within the power supply device, a CPU closes a cooling water valve. This stops the flow of cooling water that flows through the interior of the power supply device, through a cooling water duct.

Abstract: A turbomolecular pump having a pump main unit having, at least, a rotary vein provided on a rotor, a static vein for working in cooperation with the rotary vein to perform a vacuum exhaust, and a motor for driving the rotor, comprising: a controlling device that includes a motor driving circuit for converting into thermal energy, in a regenerative braking resistance, the regenerative electric current that is produced at the time of regeneratively driving the motor; and a cooling device for cooling the controlling device. A rod-shape heating resistive element is used as the regenerative braking resistance, where this resistive heating element is routed along the inner peripheral surface of an end portion 14a of the controlling device case that contacts the cooling device.

Abstract: The provision of the components requiring cooling on top of the cooling mechanism enables the cooling efficiency to be increased. Furthermore, a case of a control device is attached to the cooling mechanism whereon the components requiring cooling are disposed. The cooling mechanism fulfills the role of the contact surface of the case of the control device with the turbomolecular pump main unit, where the case does not have a case panel on the contact surface with the turbomolecular pump main unit. The cooling mechanism fulfills the role of one surface of the case for the control device, where the cooling mechanism is structured integrally with the control device. Additionally, the turbomolecular pump main unit, the cooling mechanism, and the control device are structured integrally by the turbomolecular pump main unit and the cooling mechanism being in contact.

Abstract: Disclosed is a magnetic bearing system capable of simplifying a demodulation operation and reducing a processing load associated with a magnetic levitation control. A carrier signal having a frequency fc is apply to a sensor through a filter. The sensor operates to modulate the carrier signal, and a difference amplifier operates to calculate a difference between the amplitude-modulated signal FAM (t) and a sensor reference signal Fstd (t). An A/D converter operates to A/D convert a difference signal Fsub (t) output from the difference amplifier to a discretized sensor signal. In the A/D conversion, a sampling frequency fs is set to satisfy the following relation: fc: fc=n·fs or fc=fs/2 (n is a natural number). Thus, the discretized sensor signal includes no carrier wave, and therefore a demodulation operation which has been previously essential can be simplified.

Abstract: A magnetic bearing system for use in a vacuum pump including a motor provided with a rotary blade. The magnetic bearing system including a rotary shaft rotationally holding said rotor, a motor for rotationally driving said rotary shaft, a magnetic levitation section for supporting said rotor relative to a stator through said rotary shaft in a non-contact manner, a rotation detection section for detecting a rotational speed of said rotor, a rotor-temperature detection section for detecting a temperature of said rotor; a carrier-wave generation section for supplying a common carrier wave to each of a plurality of sensors provided in said magnetic levitation section, said rotation detection section and said rotor-temperature detection section, and an A/D conversion section for sampling a sensor signal output from each of said sensors, in synchronization with said carrier wave.

Abstract: An electromagnet configured to contactlessly support a body includes an excitation amplifier configured to supply excitation current to the electromagnet, a carrier wave generation device, and a sensor configured to modulate the carrier wave and to output a sensor signal. An A/D conversion device is included for converting the sensor signal to a digital signal at a sampling frequency such that the frequency range of the sensor signal is either higher than 1/2 times the sampling frequency and lower than the sampling frequency, or higher than the sampling frequency and lower than 3/2 times the sampling frequency. In addition, a demodulation calculation device for demodulating the digitized sensor signal and a control device for controlling the excitation amplifier are provided.

Abstract: A vacuum pump capable of accurately detecting a rotor temperature based on a change in permeability of a magnetic material. Two targets are fixed to a nut opposed to a gap sensor. The nut is made of pure iron, and a surface of the nut opposed to the gap sensor serves as a target. The target has a Curie temperature greater than a temperature monitoring range, and each of the targets has a Curie temperature falling within the temperature monitoring range. When the targets become opposed to the gap sensor in turn according to rotation of a rotor, three types of signals are output from the gap sensor. The difference-signal generation means generates a difference signal of each the targets, on the basis of a signal of the target. The difference signal is compared with a reference signal V0 for detecting the Curie temperatures to detect a rotor temperature.

Abstract: A vacuum pump includes at least one magnetic body located on a circle about a rotor rotational axis and having a Curie temperature within a rotor temperature monitoring range; an inductance detecting portion facing the circle so as to establish a gap between the circle and the inductance detecting portion, for detecting a change of magnetic permeability of the magnetic body as an inductance change when the magnetic body rotates; and a carrier generation device generating a carrier signal for providing in the inductance detecting portion. An A/D conversion device samples a detection signal of the inductance detecting portion synchronously with a carrier generation by the carrier generation device, and converts the detection signal to a digital signal. A determination device determines whether or not a temperature of the rotor exceeds a predetermined temperature, based on the change of the magnetic permeability of the magnetic body.

Abstract: A vacuum pump exhausting gas by rotating a rotor relative to a stator includes a rotor having a ferromagnetic body provided on a rotational axis on, or near, a rotational axis of the end face of a rotational axis direction of a rotational body. The ferromagnetic body's Curie temperature is approximately equal to an allowable temperature of the rotor. A detecting portion disposed opposite the ferromagnetic body is configured to detect a change in magnetic permeability of the ferromagnetic body based upon a change in inductance. A revolution sensor target and an inductance-type revolution sensor are disposed in such a way as to detect both a revolution of the rotor and a change in the magnetic permeability of the ferromagnetic body. A control device halts rotor rotation when a change in magnetic permeability of the ferromagnetic body is detected and/or when a predetermined integrated time is exceeded.