Abstract: To provide a damper capable of reducing vibrations in a particular frequency band while holding the degree of freedom of installation posture of a vacuum pump. A bellows 44 and an elastic member 45 are arranged with a clearance sufficient enough to prevent contact being provided. The elastic member 45 is provided with a spring element K and a damping element C, and the bellows 44 is provided with a spring element k and a mass element m. Thus, a notch filter type vibration isolator is formed. The bellows 44 and the elastic member 45 are set at constants of the elements such that the center frequency (fc) of a notch band is close to the rotation frequency of a rotor 8. The material and expansion amount of member are adjusted so as to agree with the constants of the elements.

Abstract: To provide a magnetic bearing device capable of reducing vibration by preventing a deterioration in the control of a rotor shaft due to a variation in the axial position of the rotor shaft, while performing positional control over the rotor shaft in a specific attitude with optimal magnetic force, and to a turbo molecular pump with the magnetic bearing device mounted thereto. A sensitivity storage section 281 stores therein a sensor sensitivity used in a sensor sensitivity adjustment. The sensitivity storage section 281 outputs the stored sensor sensitivity to a sensitivity switching section. The sensitivity switching section switches the sensor sensitivity according to the situation, and outputs the result to a sensor signal amplifier section.

Abstract: A molecular pump has a casing having a gas inlet port and a gas discharge port, a stator disposed within the casing, a shaft disposed in the casing concentrically with the stator, a bearing rotatably supporting the shaft for undergoing rotation relative to the stator in a preselected direction of rotation, a rotor mounted on the shaft for rotation therewith in the preselected direction of rotation, and a motor for rotationally driving the shaft. A flange is connected to the casing at the gas inlet port.

Abstract: To provide a magnetic bearing device capable of reducing vibration by preventing a deterioration in the control of a rotor shaft due to a variation in the axial position of the rotor shaft, while performing positional control over the rotor shaft in a specific attitude with optimal magnetic force, and to a turbo molecular pump with the magnetic bearing device mounted thereto. A sensitivity storage section 281 stores therein a sensor sensitivity used in a sensor sensitivity adjustment. The sensitivity storage section 281 outputs the stored sensor sensitivity to a sensitivity switching section. The sensitivity switching section switches the sensor sensitivity according to the situation, and outputs the result to a sensor signal amplifier section.

Abstract: Vibrations generated by a vacuum pump are prevented from propagating to external equipment such as an electron microscope. A casing (a separate casing portion and a casing main body) that houses a stator, stator blades, a rotor portion, and rotor blades as an exhaust function portion is connected to an inlet port portion in which an inlet port for sucking in a gas from the outside is formed, through an elastic member. An suction space between the casing and the inlet port portion is sealed by a bellows cylinder sealing means, and motion regulating members and motion regulating members and which regulate the amount of separation between the inlet port portion and the casing, and change shape due to relative motion between the two, are formed between the inlet port portion and the casing.

Abstract: A correction value of electromagnetic current supplied to each electromagnet, such that torque generated by a motor is constant, is determined for each predetermined angle while a rotor is rotated, by which an electromagnetic current of each phase is corrected. The correction value can be calculated by a predetermined formula using an induced voltage etc. of motor. Also, the configuration may be such that at the time when the motor is driven, the correction value is calculated for each predetermined angle and is stored in a RAM, and during the operation of the motor, the correction value is read from the RAM to correct the electromagnet current.

Abstract: Disclosed are a magnetic bearing device with a vibration restraining function, a magnetic bearing device with a vibration estimating function, and a pump device with the magnetic bearing devices mounted thereto, in which it is possible to realize a reduction in vibration in the apparatus system as a whole inclusive of the equipment associated with the vacuum pump without newly providing a vibration sensor. In a vibration detector, a multiplication result obtained by multiplying the Laplace transformation of a displacement of a rotor by a predetermined transfer function is added to a multiplication result obtained by multiplying the Laplace transformation of a variation in an unbalance force acting on the rotor by the reciprocal of the mass of the rotor. The result of this calculation is reversed in polarity and is added to the output of a compensator by an adder.

Abstract: A protective device is provided for protecting a turbo molecular pump having a rotor mounted for undergoing rotation, an intake port for sucking gas by rotation of the rotor, and an exhaust port for exhausting the gas sucked from the intake port. The protective device has a detecting device for detecting the occurrence of an abnormal phenomenon in the turbo molecular pump. An abnormal phenomenon inference device infers a type of the abnormal phenomenon detected by the detecting device. A value obtaining device infers a magnitude of damage given to the turbo molecular pump by the abnormal phenomenon inferred by the abnormal phenomenon inference device and obtains a value weighted based on the inferred magnitude of the damage. A value accumulation device accumulates the value obtained by the value obtaining device. A sum obtaining device obtains a sum of the values accumulated in the value accumulation device.

Abstract: In a flange 61 provided at the suction port of a molecular pump, a hollow portion 72 is provided adjacently to a bolt hole 14. The hollow portion 72 is a through hole penetrating the flange 61. Thereby, a thin-walled portion 71 is formed between the bolt hole 14 and the hollow portion 72. If a shock in the direction of rotation of a rotor portion is provided to the molecular pump, for example, by the destruction of the rotor portion, the flange 61 slides in the direction of rotation of the rotor portion together with the molecular pump. Thereupon, a bolt fixing the flange 61 to a flange of a vacuum system hits the thin-walled portion 71, so that the thin-walled portion 71 is plastically deformed in the direction of arrow B. Thus, by the plastic deformation of the thin-walled portion 71, energy for rotating the molecular pump is consumed as energy for plastically deforming the thin-walled portion 71, so that the shock provided to the molecular pump is cushioned.

Abstract: Disclosed are a magnetic bearing device with a vibration restraining function, a magnetic bearing device with a vibration estimating function, and a pump device with the magnetic bearing devices mounted thereto, in which it is possible to realize a reduction in vibration in the apparatus system as a whole inclusive of the equipment associated with the vacuum pump without newly providing a vibration sensor. In a vibration detector, a multiplication result obtained by multiplying the Laplace transformation of a displacement of a rotor by a predetermined transfer function is added to a multiplication result obtained by multiplying the Laplace transformation of a variation in an unbalance force acting on the rotor by the reciprocal of the mass of the rotor. The result of this calculation is reversed in polarity and is added to the output of a compensator by an adder.

Abstract: Disclosed is a vacuum pump system which, even when a plurality of vacuum pumps are arranged, is capable of preventing a beat and low-frequency vibration by matching the RPM and phases of the rotary members of the vacuum pumps with each other. Control is performed such that the rotating conditions of the rotary members detected by a slave detecting device are in synchronism with the rotating condition of the rotary member detected by a master detecting device. Alternatively, control is performed such that the rotating conditions of the rotary members detected by a detecting device are in synchronism with a synchronous signal output from a synchronous signal generating device.

Abstract: There is provided a vacuum pump which suppresses the propagation of vibrations to an external container without the use of a damper. The vacuum pump has an outer cylindrical portion, a rotor portion and a stator portion accommodated within the outer cylindrical portion to define a transferring portion for a gas sucked from an inlet port, a magnetic bearing for supporting the rotor portion with respect to the stator portion, a motor for rotating the rotor portion with respect to the stator portion, and a base for supporting the outer cylindrical portion and the stator portion. A vibration absorbing member is interposed between the stator portion and the base, which has a natural frequency F=(f1+f3)/2±(f1−f3)/4, provided that f1, f2 and f3 respectively denote a natural frequency of nutation in conical mode, a natural frequency in parallel mode and a natural frequency of procession in the conical mode, when the rotor portion is rotated at a rated speed.

Abstract: Vibrations generated by a vacuum pump are prevented from propagating to external equipment such as an electron microscope. A casing (a separate casing portion and a casing main body) that houses a stator, stator blades, a rotor portion, and rotor blades as an exhaust function portion is connected to an inlet port portion in which an inlet port for sucking in a gas from the outside is formed, through an elastic member. An suction space between the casing and the inlet port portion is sealed by a bellows cylinder sealing means, and motion regulating members and motion regulating members and which regulate the amount of separation between the inlet port portion and the casing, and change shape due to relative motion between the two, are formed between the inlet port portion and the casing.

Abstract: To provide a protective device for a turbo molecular pump and a method of protecting a turbo molecular pump that may cope with abnormal phenomenon according to a kind thereof when the abnormal phenomenon occurs. A kind of abnormal phenomenon is inferred from a change rate in rpm of a rotor when the abnormal phenomenon such as an injection of atmospheric air into an intake port is generated in the turbo molecular pump or the like and a magnitude of the damage imparted to the turbo molecular pump by the abnormal phenomenon is inferred from the rpm of the rotor upon the generation of the abnormal phenomenon. Furthermore, a value weighted to the magnitude of the damage is caused to correspond to and the value is accumulated whenever the abnormal phenomenon occurs in the turbo molecular pump. When the accumulated value reaches a certain value, the protective function is effected so that the turbo molecular pump is stopped to disable its re-operation or to display an alarm to the operator or the like.

Abstract: Conventional disk recording and reproducing apparatuses have addressed a shortcoming that they cannot correct squareness errors and misalignments caused by the warpage of a disk and the eccentricity of the center hole of the disk and of the center of curvature of signal tracks. To overcome this shortcoming, a disk recording and reproducing apparatus of the present invention comprises: magnetic bearing means capable of supporting a rotary body and adjusting a relative position of the rotary body; a pickup for irradiating, with a laser beam, a recording surface of a disk mounted on a table arranged on the rotary body and receiving the laser beam reflected by the recording surface; detection means for calculating a relative positional relationship between the disk and a focal position of the laser beam based on a signal from the pickup; and control means for adjusting the position of the rotary body by controlling the magnetic bearing means.

Abstract: There is provided a vacuum pump which suppresses the propagation of vibrations to an external container without the use of a damper. The vacuum pump has an outer cylindrical portion, a rotor portion and a stator portion accommodated within the outer cylindrical portion to define a transferring portion for a gas sucked from an inlet port, a magnetic bearing for supporting the rotor portion with respect to the stator portion, a motor for rotating the rotor portion with respect to the stator portion, and a base for supporting the outer cylindrical portion and the stator portion. A vibration absorbing member is interposed between the stator portion and the base, which has a natural frequency F=(f1+f3)/2±(f1−f3)/4, provided that f1, f2 and f3 respectively denote a natural frequency of nutation in conical mode, a natural frequency in parallel mode and a natural frequency of procession in the conical mode, when the rotor portion is rotated at a rated speed.