A vacuum pump and an accessory unit of the vacuum pump for which there is no need of adjustment with respect to an operation schedule on an apparatus side, and for which version upgrade of built-in software and a change in setting data can be performed easily, are provided. In a built-in software and the like storage-portion of an optional device, new-version software and modules for updating software currently stored in a magnetic-bearing control portion, a motor driving/control portion, and a protection-function processing portion are stored. Moreover, new parameters for updating parameters currently stored in setting parameter are also stored. An application program or a parameter read out of the built-in software and the like storage-portion is sent by a user-interface processing portion to a built-in software update processing portion, and various programs and data are updated by this built-in software update processing portion.

An illustrative example embodiment of a compressor assembly includes a compressor housing having a suction inlet and a discharge outlet. A flow restricting valve allows unrestricted fluid flow in a first direction into the housing through the suction inlet and out of the discharge outlet during a first operating condition. The flow restricting valve allows a restricted fluid flow in a second, opposite direction into the housing through the discharge outlet in a second operating condition.

A compressor that vibrates a rotary shaft or changes an operating frequency of a motor, in response to a vibration frequency of a discharge passage falling outside of a normal range. The compressor may include one or more impeller configured to draw in and compress refrigerant; a motor configured to rotate the one or more impeller; a rotary shaft, to which the one or more impeller and the motor are coupled; at least two thrust bearings that limit vibration of the rotary shaft; a vibration measuring sensor configured to measure a vibration frequency of a discharge passage; and a controller configured to control the at least two thrust bearings based on the vibration frequency. Upon determining that the vibration frequency falls outside of a normal vibration frequency range, the controller controls the at least two thrust bearings to vibrate the rotary shaft a predetermined number of times.

A centrifugal compressor includes a compressor impeller that compresses air, a motor rotating the compressor impeller, and a housing including an impeller chamber, a motor chamber, and an inlet from which the air is drawn into the impeller chamber. The motor includes a stator and a rotor including a tubular member, a magnetic body, and a first shaft member and a second shaft member. The rotor includes an axial passage, a radial passage, and a connecting rod connecting the first shaft member with the second shaft member and forming a gap serving as a part of the axial passage. The housing includes a discharge port from which the air is discharged to an outside of the housing. The air outside the housing is introduced from the inlet into the motor chamber through the axial passage and the radial passage to cool the magnetic body.

A turbomachine system includes a turbomachine provided with a turbomachine rotor. The turbomachine rotor is comprised of a turbomachine shaft with a first shaft end and a second shaft end. The turbomachine shaft is supported by active magnetic bearings for rotation in a turbomachine casing. The turbomachine system further includes a rotary machine drivingly coupled to the first shaft end, and a first closed cooling circuit adapted to circulate a cooling fluid therein and fluidly coupled to the active magnetic bearings to remove heat therefrom. The closed cooling circuit includes a cooling fluid impeller mounted on the turbomachine shaft for rotation therewith and adapted to circulate the cooling fluid in the closed cooling circuit. The closed cooling circuit further includes a heat exchanger adapted to remove heat from the cooling fluid. A method of operating a turbomachine system is further disclosed.

A turbomachine system includes a turbomachine provided with a turbomachine rotor. The turbomachine rotor is comprised of a turbomachine shaft with a first shaft end and a second shaft end. The turbomachine shaft is supported by active magnetic bearings for rotation in a turbomachine casing. The turbomachine system further includes a rotary machine drivingly coupled to the first shaft end, and a first closed cooling circuit adapted to circulate a cooling fluid therein and fluidly coupled to the active magnetic bearings to remove heat therefrom. The closed cooling circuit includes a cooling fluid impeller mounted on the turbomachine shaft for rotation therewith and adapted to circulate the cooling fluid in the closed cooling circuit. The closed cooling circuit further includes a heat exchanger adapted to remove heat from the cooling fluid. A method of operating a turbomachine system is further disclosed.

A blower can be positioned in a wellbore. The blower rotatably drives or is driven by a fluid produced through the well bore. An electric machine can be positioned downhole of the blower, the electric machine configured to rotatably drive or be driven by the blower. A bearing shaft couples the blower and the electric machine. The bearing shaft transfers rotation between the blower and the electric machine. A passive magnetic radial bearing assembly magnetically supports the bearing shaft.

A blower can be positioned in a wellbore. The blower rotatably drives or is driven by a fluid produced through the well bore. An electric machine can be positioned downhole of the blower, the electric machine configured to rotatably drive or be driven by the blower. A bearing shaft couples the blower and the electric machine. The bearing shaft transfers rotation between the blower and the electric machine. A passive magnetic radial bearing assembly magnetically supports the bearing shaft.

An aerator for aerating water comprises a distribution system for distributing air below the water surface and a compressor with an air inlet and at least one air outlet. The compressor is configured to be placed below the water surface. The infiltration of water at the air inlet is prevented by an intake pipe with one open end above the water surface and the other open end has a watertight connection to the compressor. The distribution system has a watertight connection to the air outlet and, due to its nature or by at least one valve, can hold back water. The housing is in thermal contact with the water to cool the compressor. The compressor is a centrifugal compressor that comprises an impeller that is driven by a shaft that it is mounted on air bearings, magnetic bearings or both.

A position deviation calculated by a subtractor of a vacuum pump is input to the PIDs of three modes. The first PID is a PID controller for a high-bias mode, the second PID is a PID controller for a high-rigidity mode, and the third PID is a PID controller for a low-rigidity mode. The output signal of the third PID is extracted as a change of an indicator current for each clock of a PWM frequency and then the mean value of a change of an indicator current for several clocks is determined in a calculating unit. At this point, a switching control unit performs an operation on whether the mean value of the averaged change of the indicator current is larger than a preset redetermined value and then according to the result, an α value is outputted in the range of 0 to 1 from the switching control unit.