Provided is a pump monitoring device for detecting abnormalities of multiple vacuum pumps connected to the same chamber, the pump monitoring device being configured to estimate occurrence of the abnormality at any of the multiple vacuum pumps based on a comparison result of signals indicating rotation states of pump rotors of the multiple vacuum pumps.

A vacuum pump comprises: a rotary body including a rotor blade and a rotor shaft; a case rotatably housing the rotary body; a motor configured to drive the rotor shaft of the rotary body; a bearing arranged at an end portion of the rotor shaft; and at least three balance correction portions including a first balance correction portion provided on one end side of the rotary body in an axial direction, a second balance correction portion provided on the other end side of the rotary body in the axial direction, and a third balance correction portion provided between the first balance correction portion and the second balance correction portion. Balance correction by an n-plane method, where n 3, is available such that any of the three balance correction portions is accessible from an outside of the case.

A magnetic bearing control device is configured to detect, by a sensor, excitation current supplied from an excitation amplifier to a magnetic bearing configured to magnetically levitate a rotor, thereby generating a voltage equivalent signal for PWM control of the excitation amplifier based on a current setting signal based on a deviation of a rotor levitation position with respect to a target levitation position and an excitation current detection signal of the sensor. The voltage equivalent signal is generated based on the current setting signal and a current deviation signal as a difference between the current setting signal and the excitation current detection signal.

A vibration control mechanism 50 is interposed between a ball bearing 8 and a support section 2a of a base 2. The vibration control mechanism 50 is provided with a plurality of laminated sliding members 51, 52 and an elastic body 53. The vibration control mechanism 50 is provided with the plurality of sliding members 51, 52, and therefore has a plurality of sliding surfaces. As a result, it is possible to enhance a vibration control effect.

Provided are a vacuum pump and a method for the vacuum pump in which, when contact between a rotating body and a stator is sensed, the cause of the contact can be analyzed. Contact determination is made using a threshold for rotating body contact determination for a displacement signal and a threshold for rotating body contact determination for an acceleration signal. The amount of unbalance of a rotating body is determined using a threshold for amount-of-unbalance increase determination for the displacement signal and a threshold for amount-of-unbalance increase determination for the acceleration signal. When, in one of the displacement signal and the acceleration signal, the threshold for amount-of-unbalance increase determination or the threshold for amount-of-unbalance increase determination is exceeded within a predetermined time before determination of an estimated time point of contact, the contact is determined not to be caused by an increase in accumulation of products.

This is invention relates to a bearing support for a vacuum pump and, in particular, to a polymer bearing support for a vacuum pump. The invention further encompasses vacuum pumps comprising polymer bearing supports, and methods of manufacturing bearing supports.

A vacuum pump comprises: a rolling bearing configured to support a rotor shaft provided at a pump rotor; a lubrication fluid storage section configured to store lubrication fluid supplied to the rolling bearing; a MEMS element including an infinitesimal flow rate pump configured to transfer the lubrication fluid of the lubrication fluid storage section to the rolling bearing; and a first flow path of a capillary structure configured to move the lubrication fluid of the lubrication fluid storage section to the infinitesimal flow rate pump by capillary force.

A turbomachine according to an embodiment of the present disclosure may include a rotary shaft, a magnetic bearing including a core body configured to surround the rotary shaft, a plurality of poles radially extending from an inner surface of the core body toward the rotary shaft, and coils wound around the plurality of poles to levitate the rotary shaft by using a magnetic force generated by a magnetic field formed by applied electric current, a sleeve journal bearing disposed between the rotary shaft and the magnetic bearing so as to surround the rotary shaft and configured to levitate the rotary shaft by generating a dynamic pressure when the rotary shaft rotates, and a permanent magnet disposed between the plurality of poles and configured to support the rotary shaft by using a magnetic force.

A pump bearing holder has a carrier portion configured to carry a static set of magnets of a pump magnetic bearing and a support portion extending outwardly of the carrier portion to connect with a pump casing such that the pump bearing holder spans an inlet provided in the pump housing. The support portion defines a plurality of internal through-passages that, in use, allow a gas flowing through the inlet to flow through the support portion.

When a duration of current noise caused by a PWM control of each excitation amplifier is Td, a cycle of a PWM carrier signal is Tpwm, an on-duty upper limit of the PWM carrier signal under quiet environment without disturbance is Tonu, and an on-duty lower limit of the PWM carrier signal under the quiet environment without the disturbance is Tonl, the AD sampling period includes a first AD sampling period between a point after a lapse of the time Td after a start of the cycle Tpwm and a point after a lapse of a time (TpwmTonu) from the start of the cycle Tpwm, and a second AD sampling period between a point after a lapse of a time (TpwmTonl+Td) from the start of the cycle Tpwm and an end point of the cycle Tpwm.