A magnetic bearing assembly for a rotary machine may lose power and fail to support the rotating assembly resulting in damage to magnetic bearing assembly and/or other components. An auxiliary bearing assembly may be used to support the rotating assembly during such a failure. The auxiliary bearing assembly is located radially inwards of the magnetic bearing assembly and may reduce resonance and/or whirl of the rotating assembly during failure of the magnetic bearing assembly.

A magnetic bearing assembly for a rotary machine may lose power and fail to support the rotating assembly resulting in damage to magnetic bearing assembly and/or other components. An auxiliary bearing assembly may be used to support the rotating assembly during such a failure. The auxiliary bearing assembly is located radially inwards of the magnetic bearing assembly and may reduce resonance and/or whirl of the rotating assembly during failure of the magnetic bearing assembly.

A control apparatus includes a constant storage portion that stores constant values of an electromagnet coil including a resistance value Rm, an inductance Lm, a sampling time Ts, etc. A current storage portion stores previous current command values Ir having been regularly sampled by a microcomputer inside a current control circuit. A low-frequency feedback circuit generates a signal for suppressing an error between DC components and low-frequency components of an input current command value Ir and a detected current value IL and outputs the signal. An output voltage computing circuit calculates, based on the input current command value Ir[n+1], a stored value Ir[n] of the current storage portion, a stored value of a constant storage portion, and the signal of the low-frequency feedback circuit, a voltage for suppling the electromagnet coil with a current in accordance with a command, and outputs the calculated voltage.

A control apparatus includes a constant storage portion that stores constant values of an electromagnet coil including a resistance value Rm, an inductance Lm, a sampling time Ts, etc. A current storage portion stores previous current command values Ir having been regularly sampled by a microcomputer inside a current control circuit. A low-frequency feedback circuit generates a signal for suppressing an error between DC components and low-frequency components of an input current command value Ir and a detected current value IL and outputs the signal. An output voltage computing circuit calculates, based on the input current command value Ir[n+1], a stored value Ir[n] of the current storage portion, a stored value of a constant storage portion, and the signal of the low-frequency feedback circuit, a voltage for suppling the electromagnet coil with a current in accordance with a command, and outputs the calculated voltage.

A motor includes a bearing having a rolling member disposed between an inner ring and an outer ring, a spring connected to the outer ring, and a pusher connected to the spring and configured to move to a first position spaced apart from the inner ring by the spring. The pusher is further configured to move to a second position at which friction with the inner ring is caused by a pressure of air. The inner ring is spaced apart from the rotating shaft by a gap between the inner ring and the rotating shaft when the pusher is at the second position.

The turbomachine comprises a casing arrangement and a shaft supported for rotation therein. The shaft is rotatingly supported by a first and second bearing unit. First and second compressor sections are provided in the casing arrangement. The first compressor section comprises a first compressor impeller mounted on the shaft for rotation therewith, and the second compressor section comprises a second compressor impeller mounted on the shaft for rotation therewith. The turbomachine further comprises a first turboexpander and a second turboexpander mounted on the shaft for rotation therewith in the casing arrangement.

A shaft assembly for use with a turbine engine includes a shaft and a magnetic mode control unit. The shaft extends along an axis and is configured to rotate about the axis. The magnetic mode control unit is configured to control deflection of the shaft as the shaft rotates about the axis.

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 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 turbo chiller that has an oil-free configuration, which reduces the frequency of maintenance and maintenance-induced release of refrigerant, and can achieve a reduced environmental impact by utilizing the characteristics of the low-pressure refrigerant R1233zd(E) that reaches negative pressure at a saturation temperature of 18° C. or lower. The turbo chiller comprises a refrigeration cycle that includes a turbo compressor, a condenser, a decompression device, and an evaporator connected in sequence via piping and is filled with a refrigerant; wherein the refrigerant is a low-pressure refrigerant R1233zd(E) refrigerant with low global warming potential and low ozone depletion potential; the turbo compressor has a direct drive configuration in which a rotating shaft of impellers is directly joined to a motor; and the rotating shaft is supported by magnetic bearings.