Disclosed is a method for calibrating at least one gap sensor, the at least one gap sensor being provided on a magnetic bearing supporting a floating body in a non-contact manner by an electromagnetic force, the at least one gap sensor being configured to detect a gap between the floating body and a reference object that serves as a positional reference for position control of the floating body. The method includes: constructing a transformation formula for transforming an output of the at least one gap sensor into the gap using three or more constraints that are set as conditions for associating the gap with the output of the at least one gap sensor.

A cooling system for a motor to power a compressor in a vapor compression system is provided. The cooling system includes a housing with a cavity enclosing the motor and defining a central axis and fluid directing features extending into the cavity and oriented parallel to the central axis. The cooling system further includes a fluid circuit configured to circulate a cooling fluid between the housing and the motor. The fluid circuit includes a first cooling fluid path defined by directing features that cause a first portion of cooling fluid to travel around a first portion of the motor and a second cooling fluid path defined by fluid directing features that cause a second portion of cooling fluid to travel around a second portion of the motor. The second portion of the motor is located opposite the first portion.

A cooling system for a motor to power a compressor in a vapor compression system is provided. The cooling system includes a housing with a cavity enclosing the motor and defining a central axis and fluid directing features extending into the cavity and oriented parallel to the central axis. The cooling system further includes a fluid circuit configured to circulate a cooling fluid between the housing and the motor. The fluid circuit includes a first cooling fluid path defined by directing features that cause a first portion of cooling fluid to travel around a first portion of the motor and a second cooling fluid path defined by fluid directing features that cause a second portion of cooling fluid to travel around a second portion of the motor. The second portion of the motor is located opposite the first portion.

A method of controlling, by a controller for a compressor (200), pressure at plurality of magnetic motor thrust bearings (360, 370) for a motor (280) disposed within a housing (220) for the compressor (200), wherein the motor (280) and an impeller (270) are disposed on a compressor shaft (260) within the housing, the method including: monitoring current at each of the plurality of magnetic motor thrust bearings (360, 370), controlling a flow regulator (400) in a bypass loop (380) for the impeller (270) to decrease flow through the bypass loop when a first current in a first of the plurality of magnetic motor thrust bearings (360, 370) exceeds a second current in a second of the plurality of magnetic motor thrust bearings (360, 370), and controlling the flow regulator (400) to increase flow through the bypass loop (380) when the second current exceeds the first current.

A method of controlling, by a controller for a compressor (200), pressure at plurality of magnetic motor thrust bearings (360, 370) for a motor (280) disposed within a housing (220) for the compressor (200), wherein the motor (280) and an impeller (270) are disposed on a compressor shaft (260) within the housing, the method including: monitoring current at each of the plurality of magnetic motor thrust bearings (360, 370), controlling a flow regulator (400) in a bypass loop (380) for the impeller (270) to decrease flow through the bypass loop when a first current in a first of the plurality of magnetic motor thrust bearings (360, 370) exceeds a second current in a second of the plurality of magnetic motor thrust bearings (360, 370), and controlling the flow regulator (400) to increase flow through the bypass loop (380) when the second current exceeds the first current.

Magnetic levitation bearing structure includes a cylinder body, a rotating shaft, a motor stator, a motor rotor, an axial bearing, a radial bearing and a displacement sensing device; the displacement sensing device, the axial bearing stator, and the radial bearing stator are directly fixed on an inner wall of the cylinder body.

A motor assembly includes a rolling bearing installed on a rotation shaft between an impeller and a rotor to support a first support of the rotation shaft, and a motor housing having a stator. The motor housing has a gas bearing bracket for accommodating a second support of the rotation shaft disposed at a side opposite to the first support with respect to the rotor. The motor assembly includes a gas bearing assembly in the gas bearing bracket to support rotation of the second support of the rotation shaft. The gas bearing assembly includes a gas bearing for surrounding the second support. The gas bearing is spaced apart from the second support of the rotation shaft to define a gap therebetween when the rotation shaft rotates. The gas bearing assembly includes an elastic member interposed between the gas bearing bracket and the gas bearing to elastically support the gas bearing.

A motor assembly includes a rolling bearing installed on a rotation shaft between an impeller and a rotor to support a first support of the rotation shaft, and a motor housing having a stator. The motor housing has a gas bearing bracket for accommodating a second support of the rotation shaft disposed at a side opposite to the first support with respect to the rotor. The motor assembly includes a gas bearing assembly in the gas bearing bracket to support rotation of the second support of the rotation shaft. The gas bearing assembly includes a gas bearing for surrounding the second support. The gas bearing is spaced apart from the second support of the rotation shaft to define a gap therebetween when the rotation shaft rotates. The gas bearing assembly includes an elastic member interposed between the gas bearing bracket and the gas bearing to elastically support the gas bearing.

Embodiments of the inventive technology include a centrifugal fan having a damper repositionable between a closed position and a fully seated open position, and a magnetic coupler that serves to fully seat that damper it its open configuration, so as to prevent undesired effects such as slippage and/or rocking of that damper relative to rotatable componentry against which it is pressed, during operation of the fan. The coupler may be configured so that the damper may decouple from rotatable componentry, e.g., upon a certain reverse pressure differential, and translate to a closed position.

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.