Koyo Seiko Company, Ltd.

Jtekt Corporation

Hirochika Ueyama

Manabu Taniguchi

Nobutsuna Motohashi

Atsushi Kubo

Ryoichi Takahata

Yasukata Miyagawa

Hironori Kameno

Tadashi Fukao

Yasutaka Miyagawa

Kenji Ooiso

Toshihiko Daido

Yasuhiko Ishii

Naoki Morimura

Tetsuaki Numata

Yasuhiro Yukitake

Makoto Nohara

Isao Kuramoto

Hidenobu Nagano

Kenichi Kouduki

A first spacer, a second tubular member, and a second spacer are externally fitted and fixed to an outer peripheral surface of a nut. The second tubular member is formed by stacking a plurality of silicon steel plates without any gap, and is arranged between the first spacer and the second spacer axially. The outer diameter of an outer peripheral surface of the second tubular member is made larger than the outer diameter of an outer peripheral surface of the first spacer and the outer diameter of an outer peripheral surface of the second spacer. A detection surface of a first displacement detector is made to radially face a contact portion between the second spacer and the second tubular member, while a detection surface of a second displacement detector is made to radially face a contact portion between the first spacer and the second tubular member.

Rolling bearing device with sensor

If the ambient temperature of a pressure volute measured by a temperature sensor exceeds 0&#xb0; C., a compressor is instantly started at normal operation. If the temperature of the pressure volute measured by the temperature sensor is 0&#xb0; C. or lower, vibration along the axial direction is given to the rotary shaft by way of an axial magnetic bearing. If the vibration amplitude of the thus given vibration exceeds a predetermined value, the compressor is started at normal operation after idle operation. On the other hand, if the vibration amplitude is lower than a predetermined value, the heater is actuated to heat the pressure volute only for a predetermined time. Thereafter, the ambient temperature is detected again, and if the ambient temperature exceeds 0&#xb0; C., the compressor is started.

Centrifugal air compressor

A rolling bearing assembly for a wheel includes a cylindrical fixed bearing ring fixed to a vehicle body side, a rotary bearing ring rotatably inserted to inside of the fixed bearing ring, and plural rows of rolling elements rollably arranged between the bearing rings. An annular sensor housing is attached to an inboard side end portion of the fixed bearing ring and includes a plurality of displacement sensors for detecting gaps between the displacement sensors and outer peripheral surfaces of inboard side end portions of the rotary bearing ring in a circumferential direction. Further, an inboard side end portion of the sensor housing is sealed by an inner side seal device.

Rolling bearing assembly for wheel

A rolling bearing device with a sensor includes a rotational component estimator that extracts a rotational synchronization component included in the rotation of an inner shaft relative to an outer ring from each of a signal output by a first displacement detector and a signal output by a second displacement detector. The rotational component estimator performs rotational operation and integration operation.

A control magnetic bearing device comprises a plurality of control magnetic bearings for contactlessly supporting a rotor, an electric motor for rotating the rotor, a magnetic bearing drive circuit for driving the magnetic bearings, an inverter for driving the electric motor, a main control circuit for controlling the magnetic bearing drive circuit and the inverter, and a power source unit connected to an external power source for supplying electric power to the magnetic bearing drive circuit, the inverter and the main control unit. The main control unit has software-programmable digital processing means for controlling the inverter in accordance with an input voltage value from the power source unit.

Control magnetic bearing device

A rolling element in a stationary state as surrounded by magnetic bearings is moved until it abuts against a protective bearing, and thereby a mean value of movement spans S is determined. A machine type is determined based on a fact that the mean value of movement spans varies depending upon the types of machine bodies, and then the setting of control parameters is made. In this manner, a control unit of the magnetic bearing is adapted for multiple types of machine bodies.

Controllable magnetic bearing apparatus and method for determining a machine type of a magnetic bearing

A magnetic bearing device includes a pair of electromagnets holding a rotary body at opposite sides thereof in the direction of each of control axes, a detector for detecting the position of the rotary body, and an electromagnet controller having an integral operation unit for controlling the electromagnets based on the result of detection of the position. The electromagnet controller sets as a target levitated position of the rotary body the position of the rotary body corresponding to the median of an integral output of the integral operation unit when the rotary body is magnetically levitated in the vicinity of one of limit positions in the direction of the control axis determined by protective bearings and an integral output of the unit when the rotary body is magnetically levitated in the vicinity of the other limit position.

Magnetic bearing device

In a control unit for magnetic bearing, a sampling frequency of a DSP is varied according to a number of rotation of a rolling element . Thus, a frequency band to be damped by a notch filter as a digital filter is varied in correspondence with a resonance frequency associated with a natural frequency and a rotational vibration frequency, thereby to damp a resonance signal contained in a control signal. The occurrence of resonance is thus prevented through digital control.

Controller of magnetic bearing

In a turbo-molecular pump, a rotor is supported by a magnetic bearing ( ) in a non-contact mode. A pump control section ( ) has a magnetic bearing control device ( ) with a digital signal operating processor or DSP ( ) which is programmable by a software or which can execute a programmed software. The digital signal operating processor ( ) performs the control of a heating system, namely, a heater, as well as the control of the magnetic bearing ( ).

Turbo-molecular pump

A magnetic bearing device comprises a machine main body having position sensors for detecting the position of a rotary body and magnetic bearings for magnetically contactlessly supporting the rotary body, a controller for controlling the magnetic bearings based on the signals from the position sensors, a data processing computer installed at a location away from the controller, and modems for connecting the controller to the computer by communication lines.

Remote bearing device with remote diagnostic capability

A magnetic bearing device comprising a magnetic bearing main body having at least electromagnets for magnetically levitating a rotary body and position sensors for detecting the position of the rotary body, and a controller connected to the main body by a cable for controlling the electromagnets based on output signals of the position sensors. The magnetic bearing main body is provided with memory means having stored therein characteristics of the rotary body and the electromagnets.

Magnetic bearing device and method of starting the device

System for controlling plural magnetic bearing devices from a remote location

A control magnetic bearing includes a mechanical main unit and a controller for controlling an excitation current supplied to electromagnets. The mechanical main unit comprises displacement sensors and magnetic bearing sets for supporting a rotor in a non-contacting manner. The controller is provided with a digital signal processor (DSP) which outputs a digital control signal for controlling the excitation current on the basis of a digital displacement signal. The DSP includes identification unit for identifying the type of the mechanical main unit. The identification unit identifies the type of the mechanical main unit on the basis of the response by the rotator.

Control magnetic bearing

In the magnetic bearing apparatus, there is provided a current sensor for detecting a current flowing in a motor. When the current increases over a reference value, a DSP enhances a support stiffness of the magnetic bearing, thereby securing a stable rotation of the rotor.

Controllable magnetic bearing apparatus

In a turbo molecular pump having a rotor magnetically supported in a non-contact manner by a magnetic bearing, a pump controller has a magnetic bearing controller having a programmable digital signal processor. This digital signal processor not only controls the magnetic bearing, but also controls the heater, thus serving as a temperature regulator.

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Hirakata, Japan

Hirochika Ueyama