Shimadzu Corporation

Yoshihiro Nagano

Junichiro Kozaki

Masaki Ohfuji

Nobuhiko Moriyama

Toshiki Yamaguchi

Masaki Ofuji

Takuto Onishi

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.

Magnetic bearing device and vacuum pump

An electromagnet has a core with a pair of magnetic poles, a primary coil wound around the core, and a series circuit of a first auxiliary coil wound around the first magnetic pole of the core, a second auxiliary coil wound around the second magnetic pole of the core, and capacitors, and is connected in parallel to the primary coil and the series circuit. The first and the second magnetic poles are each divided into a plurality of split magnetic poles. The first auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in the plurality of split magnetic poles of the first magnetic pole so that the mutual inductance with the primary coil becomes zero. The second auxiliary coil is composed of a plurality of split auxiliary coils wound around the respective pole in a plurality of split magnetic poles of the second magnetic pole so that the mutual inductance with the primary coil becomes zero.

Sensorless magnetic levitation vacuum pump and sensorless magnetic levitation device

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.

Turbomolecular pump device

A magnetic levitation type vacuum pump includes an electromagnet magnetically levitating a rotor by a magnetic force, an electromagnet driving circuit supplying an electromagnet current including a magnetic levitation control current component and a carrier wave current component having a frequency band higher than the magnetic levitation control current component to the electromagnet coil, a levitated position detecting circuit detecting the carrier wave current component and generating a levitated position signal of the rotor, a magnetic levitation control circuit inputting a current command of the magnetic levitation control current component to the electromagnet driving circuit based on the levitated position signal. The electromagnet coil has a primary coil and a secondary coil connected in parallel with the primary coil. An interrupting circuit connected in series with the secondary coil for the carrier wave current component passing therethrough and interrupting the magnetic levitation control current component is further included.

Magnetic levitation type vacuum pump and magnetic levitation device

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 portionof the controlling device case that contacts the cooling device.

Turbomolecular pump device and controlling device thereof

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.

Turbomolecular pump

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.

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Kyoto, Japan

Yoshihiro Nagano