A magnetic bearing device comprises: a magnetic bearing configured to magnetically levitate and support a rotor rotatably driven by a sensor-less motor; a detector configured to detect displacement from a levitation target position of the rotor to output a displacement signal; a signal processor configured to compensate, based on motor rotation information from a motor controller of the sensor-less motor, for the displacement signal to reduce a vibration component of electromagnetic force of the magnetic bearing; and a current controller configured to generate control current of the magnetic bearing based on the displacement signal having been processed in the signal processor.

A pump lubricant supply system has a lubricant reservoir and at least one contactor to engage a lubricant transfer device provided on a rotor shaft of a pump to transfer lubricant from the lubricant reservoir to the lubricant transfer device via the at least one contactor. The lubricant reservoir includes at least a first reservoir portion formed of a first elongate strip of porous material wound to define a first lubricant container body having a longitudinal axis that extends transverse to the longitudinal axis of the elongate strip.

A vacuum pump for rotary driving a rotor by a motor to perform vacuum pumping, wherein a motor rotor of the motor includes a yoke fixed to a shaft of the rotor, and a permanent magnet held at the yoke, and the yoke includes a holding portion provided apart from the shaft and configured to hold the permanent magnet, and a pair of fitting portions provided respectively at both ends of the holding portion in an axial direction and bonded to the shaft by fitting, and a radial thickness dimension of each fitting portion is set less than that of the holding portion.

A micro flow device for separating or isolating cells from a bodily fluid or other liquid sample uses a flow path where straight-line flow is interrupted by a pattern of transverse posts. The posts are spaced across the width of an expanded collection chamber region in the flow path, extending between the upper and lower surfaces thereof; they have rectilinear surfaces, being curved in cross-sections, e.g. circular or tear-drop shaped, and are randomly arranged so as to disrupt streamlined flow. The device is oriented so that its lower surface is aligned at about 45? to the horizontal. Sequestering agents, such as Abs, which are attached to surfaces of the collection region via a hydrophilic coating, preferably a permeable hydrogel containing isocyanate moieties, are highly effective in capturing cells or other targeted biomolecules while the remainder of the liquid sample exits horizontally.

A magnetic levitation control device comprises: a control signal generation section configured to generate a first excitation current control signal based on current deviation information on the excitation current detection signal with respect to the current setting signal and a second excitation current control signal based on the current setting signal; and a selection section including a first switching section configured to select either one of the first excitation current control signal or the second excitation current control signal or a second switching section configured to select either one of a third excitation current control signal obtained by summation of the first excitation current control signal and the second excitation current control signal or the second excitation current control signal. The excitation amplifier is PWM-controlled based on the excitation current control signal selected by the selection section.

An object of the present invention is to provide a magnetic bearing device designed to achieve reduction in cost and size of a circuit by omitting a DC/DC converter that has been used for obtaining a control power voltage of a magnetic bearing, and to provide a vacuum pump having the magnetic bearing device. The magnetic bearing device has: position detection means for detecting a radial position and an axial position of a rotor; magnetic bearing means for controlling the radial position and the axial position with an electromagnet based on the radial position and the axial position detected by the position detection means; an excitation circuit that includes a switching element for connecting/disconnecting between the electromagnet and a power supply; electromagnetic current detection means for detecting a signal of a current flowing through the electromagnet; power supply voltage detection means for detecting a signal of a voltage of the power supply; and pulse width calculation means for calculating, at each timing, a pulse width for operating pulse control for the switching element. The pulse width is calculated based on the voltage of the power supply detected by the power supply voltage detection means and the current detected by the electromagnetic current detection means.

A micro flow device (11, 71) for separating or isolating cells from a bodily fluid or other liquid sample uses a flow path where straight-line flow is interrupted by a pattern of transverse posts (23, 81). The posts are spaced across the width of an expanded collection chamber region (17, 75) in the flow path, extending between the upper and lower surfaces thereof; they have rectilinear surfaces, being curved in cross-sections, e.g. circular or tear-drop shaped, and are randomly arranged so as to disrupt streamlined flow. The device is oriented so that its lower surface is aligned at about 45? to the horizontal. Sequestering agents, such as Abs, which are attached to surfaces of the collection region via a hydrophilic coating, preferably a permeable hydrogel containing isocyanate moieties, are highly effective in capturing cells or other targeted biomolecules while the remainder of the liquid sample exits horizontally.

The present invention is directed to a magnet for a magnetic bearing arrangement, a bearing arrangement comprising said magnet, and a vacuum pump comprising said bearing arrangement. In particular the invention can be particularly useful in a magnetic bearing arrangement that reduces stray magnetic fields for a turbomolecular vacuum pump, although it is understood that the invention is not limited to this field and other applications will be understood by the skilled person.

Provided is a magnetic bearing device which allows easy initial adjustment and allows optimal bearing control to be performed by a simple algorithm without increasing a memory capacity of a controller. A pair of square multipliers and an adder acquire respective steady-state current values of a pair of electromagnets which attract a rotor shaft of a magnetic bearing not shown in opposite radial directions, square the respective steady-state current values, and add up the respective squared steady-state current values. Then, to optimally change respective currents in the electromagnets in accordance with a mounting posture of the magnetic bearing, a correction coefficient arithmetic operator calculates a correction gain instruction value acting on the electromagnets from the steady-state current values squared/added up. Then, a gain instruction value obtained by adding the correction gain instruction value to a fundamental gain of a control circuit for the electromagnets is input to a gain amplifier. The gain amplifier generates a corrected current instruction value on the basis of the gain instruction value and optimally controls the magnetic bearing.

A turbomolecular pump has a housing, a rotor shaft supported by a plurality of bearings for rotation relative to the housing about an axis of rotation, a deflector, a lubricant supply system and a lubricant transfer device provided on the rotor shaft. The bearings include a rolling bearing that receives lubricant from the lubricant supply system to via the lubricant transfer device. The rolling bearing is disposed intermediate the lubricant transfer device and the deflector and the deflector is configured to deflect lubricant that passes through the rolling bearing outwardly with respect to the rotor shaft.