Abstract: There is provided an electric discharge gas laser comprising a housing, a rotating fan, a bearing device and a control. The housing contains a laser gas. The rotating fan is provided in the housing to circulate the gas in the housing. The bearing device magnetically supports a rotating shaft. The bearing device is provided with a sensor device comprising a sensor and a signal processor. The sensor senses the position of the rotating shaft to generate signals indicating the position of the rotating shaft. The signal processor receives and processes the signals delivered from the sensor to output processed signals. The control is separated from the bearing device and is functionally associated with the bearing device to receive the processed signal from the sensor device for controlling the bearing device on the basis of the processed signals.

Abstract: A gas transfer machine for use as a vacuum pump, for example, has a pump rotor mounted on a rotatable shaft for transferring a gas, and a reluctance-type motor for rotating the rotatable shaft. The reluctance-type motor has a stator, a motor rotor surrounded by the stator, and a shield member isolating the stator from the motor rotor. The motor rotor is directly coupled to the rotatable shaft and has a plurality of magnetic salient poles.

Abstract: A magnetic levitation rotating machine is provided which can stably detect the displacement and rotating speed of a rotator and, at the same time, can reduce the size of the whole apparatus, that is, can render the whole apparatus compact. The magnetic levitation rotating machine for supporting a rotator in a levitated state by magnetic force of an electromagnet or a permanent magnet comprises: a position detection plane provided in the rotator and a concave and/or a convex provided in the plane; a displacement sensor provided on the fixed side, for detecting the displacement of the plane including the concave or the convex; and a detection mechanism for detecting the displacement of the rotator and the rotating speed of the rotator from the output of the displacement sensor.

Abstract: A discharge-pumped excimer laser device has a casing, a pair main discharge electrodes, a cross-flow fan for producing a high-speed laser gas flow between the main discharge electrodes, the cross-flow fan having a rotatable shaft projecting from opposite ends thereof, magnetic bearings, the rotatable shaft being rotatably supported by the bearings, protective bearings for supporting the rotatable shaft when the magnetic bearings are not in operation, and a motor for actuating the cross-flow fan. The magnetic bearings include radial magnetic bearings disposed on the opposite ends of the rotatable shaft. One of the radial magnetic bearings which is disposed closely to the motor has a bearing rigidity greater than the bearing rigidity of the magnetic bearing that is disposed remotely from the motor.

Abstract: There is provided a magnetic bearing in which a magnetic gap between magnetic pole faces of the stator and the rotor can be reduced, and which is reduced in size and has excellent corrosion resistance. This magnetic bearing comprises: a magnetic bearing rotor 16 provided on the rotary shaft; and a magnetic bearing stator 41 provided around the magnetic bearing rotor, wherein the magnetic bearing stator comprises: a stator core 42 having magnetic pole faces exposed toward the magnetic bearing rotor; excitation coils 43a attached to the stator core; and corrosion-resistant members 43 for shielding the excitation coils 43a from a corrosive atmosphere. The corrosion-resistant member can be formed by molding a ceramic or glass type hardenable material in a state such that the excitation coil 43a is embedded therein. The corrosion-resistant member may comprise a case 43c formed from the corrosion-resistant material.

Abstract: There is provided an excimer laser apparatus in which deterioration of the laser gas in the laser container can be suppressed, and damage to the magnetic bearings caused by the laser gas can be suppressed, and which can be reduced in size and operated efficiently, and has a low power consumption. Each electromagnet (stator) 7-1 of a magnetic bearing 7 for supporting a rotary shaft 4 of a circulation fan 3 includes excitation coils, each of which is arranged as one unit by embedding a coil body in a ceramic or glass type hardened material which is nonmagnetic and has corrosion resistance against a laser gas. The excitation coils are attached to magnetic poles comprising magnetic bodies. Alternatively, an arrangement may be made, such that coil wires 108b of a radial magnetic bearing 108 are isolated from a corrosive atmosphere by means of a separation wall 124 while projecting portions of cores 108b extend through the separation wall 124 and are exposed toward a magnetic bearing rotor 108f.

Abstract: A magnetic bearing control device that can operate a motor with low noise, has a simple system construction and is compact and inexpensive comprises: at least a pair of opposed electromagnets for supporting a suspended unit without contact; a motor M for rotating the suspended unit; and a controller for driving and controlling them.

Abstract: The present invention provides a discharge-pumped excimer laser device which includes a laser chamber filled with a laser gas that is deteriorated to a small extent, magnetic bearings and a motor that are resistant to the entry of dust particles, and parts that are held in contact with the laser gas and suffer little damage, and has a long service life.

Abstract: The present invention provides an apparatus and a method for forming a desired gas atmosphere in an inner space of a casing.

Abstract: A circulation fan apparatus including a hermetic vessel 1 containing a corrosive process gas therein, and a circulation fan 2 installed in the hermetic vessel, rotors 2-1, 2-2 of the circulation fan are rotatably supported by bearings, wherein the bearings comprises control-type radial magnetic bearings 4, 5 and at least control-type axial magnetic bearing 6, 7, displacement sensor targets 4-1, 5-1, 6-1, and 7-1 and rotor-side magnetic poles 4-2, 5-2, 6-2, and 7-2 of radial magnetic bearings 4 and 5 and axial magnetic bearings 6 and 7 are fixed to the rotors 2-1 and 2-2 of the circulation fan 2 and are disposed in the hermetic space communicating with the hermetic vessel, and displacement sensors 4-3, 5-3, 6-3, and 7-3 and stator-side magnetic poles 4-4, 5-4, 6-4, and 7-4 opposing the displacement sensor targets and rotor-side magnetic poles are disposed outside of the hermetic vessel with cans 14, 15, 17, and 18 interposed therebetween, whereby even when the circulation fan 2 is rotated at a high speed and u

Abstract: A magnetic bearing device for use with a motor-combined structure having magnetic bearings supporting a rotatable shaft out of contact therewith and a motor for rotating the rotatable shaft. A common power supply supplies electric power to the magnetic bearings and the motor, and a motor drive power supply limits variations of the electric power supplied to the motor to at most a predetermined level with respect to variations of electric power supplied to the common power supply.

Abstract: An excimer laser apparatus comprises a container sealing a laser gas including a halogen gas therein, a pair of discharge electrodes disposed in the container for inducing an electric discharge capable of oscillating a laser light, and a circulating fan with a shaft for producing a high-speed laser gas stream between a pair of the discharge electrodes. Both ends of the shaft are rotatably supported by rotor-stator mechanisms, or one end of the shaft is rotatably supported by a rotor-stator mechanism, and the other end of the shaft is supported by a magnetic bearing. The rotor-stator mechanism comprises a rotor attached to the shaft of the circulating fan, a stator provided at a position opposed to the rotor, an electric motor winding provided in the stator for applying torque to the rotor, and a position control winding provided in the stator for producing a magnetic force to levitate and support the rotor.

Abstract: A magnetic bearing device has an object levitated in an arbitrary position between confronting electromagnets. Positional displacement sensors detect a positional displacement of the object. When the electromagnets are successively energized, the object is moved in a mechanically movable maximum range between the electromagnets, and maximum and minimum values of a detected positional displacement signal from the positional displacement sensors are detected. A middle value between the maximum and minimum values is calculated and compared with a threshold level. An adjustment signal is applied to an offset corrector which produces an offset-corrected signal from the detected positional displacement signal, so as to substantially eliminate the difference between the middle value and the threshold level so that the middle value represents a position in which the object is to be levitated between the electromagnets.

Abstract: The present invention is to provide a magnetic bearing controller capable of reliably controlling the position of a floating member at a target position, even when the length of the cable connecting the magnetic bearing and the controller is changed. The magnetic bearing controller comprises: an electromagnet for supporting a floating member in a floating state; sensors (Z1, Z2) for sensing the floating position of the floating member; and a controller for supplying sensor signals and an exciting currents via cables to the sensors and electromagnets, respectively, in order to support the floating member at a predetermined floating position based on signals received from the sensors, wherein the controller comprises.

Abstract: An excimer laser device which is capable of keeping the rotational speed of a fan constant and uniformizing a laser gas flow between main discharge electrodes even when the pressure of a laser gas filled in a casing varies. The excimer laser device includes a casing filled with a laser gas; a pair of main discharge electrodes disposed in the casing for producing an electric discharge to discharge-pump the laser gas at a high repetition rate; a fan for producing a high-speed laser gas flow between the main discharge electrodes; bearings, the fan having a rotatable shaft rotatably supported by the bearings; a motor for actuating the fan; a rotational speed detecting device for detecting a rotational speed of the fan; and control device for controlling at least one of a voltage and a frequency to be supplied to the motor based on the rotational speed of the fan detected by the rotational speed detecting device, thereby to control the rotational speed of the fan at a constant level.

Abstract: A magnetic levitation rotating machine is provided which can stably detect the displacement and rotating speed of a rotator and, at the same time, can reduce the size of the whole apparatus, that is, can render the whole apparatus compact. The magnetic levitation rotating machine for supporting a rotator in a levitated state by magnetic force of an electromagnet or a permanent magnet comprises: a position detection plane provided in the rotator and a concave and/or a convex provided in the plane; a displacement sensor provided on the fixed side, for detecting the displacement of the plane including the concave or the convex; and a detection mechanism for detecting the displacement of the rotator and the rotating speed of the rotator from the output of the displacement sensor.

Abstract: There is provided an electric discharge gas laser comprising a housing containing a laser gas; a rotating fan provided in the housing to circulate the gas in the housing; a bearing device for magnetically supporting a rotating shaft of the rotating, the bearing device being provided with a sensor device comprising a sensor for sensing the position of the rotating shaft to generate signals indicating the position of the rotating shaft, and a signal processor for receiving and processing the signals delivered from the sensor to output processed signals; and a control separated from the bearing device and functionally associated with the bearing device to receive the processed signals from the sensor device for controlling the bearing device on the basis of the processed signals.

Abstract: A magnetic bearing device has an electromagnet for levitating an object under electromagnetic forces, a displacement sensor for detecting the displacement of the levitated object, a controller for supplying a signal to the displacement sensor through a cable and a current to the electromagnet through a cable, and a protective plate of nonmagnetic metal material disposed between the displacement sensor and the levitated object. The controller includes a levitation control system having a noise removing filter for preventing an abnormal signal caused by the protective plate from being applied to the displacement sensor.

Abstract: A magnetic suspending device which can detect the temperature of a controlled object and assure a safe operation thereof without any need for any special construction or work to the device and any special maintenance is disclosed.

Abstract: A turbomolecular pump comprising a rotor and a stator housed in a casing and forming an exhaust channel therebetween, and a suction port and a discharge port formed in the casing; wherein the turbomolecular pump has a valve body for opening and closing the suction port, the valve body is movable in an axial direction of the turbomolecular pump, a valve driving mechanism for driving the valve body via a valve body supporting member which extends through a throughhole formed in the rotor and/or the stator and magnetic bearing units for non-contactingly supporting the valve body supporting member within the throughhole, whereby a turbomolecular pump having a compact overall construction including valve units can be provided.