Abstract: A compressor for a heat transfer circuit includes a variable frequency drive (VFD), an electric motor that rotates a driveshaft, bearing(s) for supporting the driveshaft, a backup gas supply, and a power supply. During a utility power interruption, the backup gas supply operates utilizing DC electrical power generated by a back electromotive force of the electric motor. A method of operating an electric power supply system for a compressor includes operating in a utility power mode and operating in a backup power mode during a utility power interruption. In the utility power mode, AC electrical power is supplied from the VFD to the motor. In the backup power mode, DC electrical power generated in the VFD by a back electromotive force of the motor it used to operate a backup gas supply to supply compressed working fluid to gas bearing(s) of the compressor.

Abstract: Disclosed is a hermetic AC electric motor that includes harmonics shunting such that high frequency harmonics are shunted from the AC electric motor without the use of one or more high frequency filters in the associated motor drive. A related method of operating an AC electric motor includes shunting high frequency harmonics to a fluid passing through the AC electric motor. Also disclosed is a simplified variable speed motor drive system which eliminates the need for a filter for removing high frequency harmonics.

Abstract: Permanent magnet rotors for electric motors, particularly electric motors for use in compressors, improve the electromagnetic efficiency of the motor. The rotors can include retention of surface permanent magnets using one or more of retaining features on the motor and/or pole spacers interfacing with corresponding features on a rotor core, the use of a monolithic magnet in the rotor, and/or use of a carbon fiber sleeve. The rotor can include an eddy current shield, disposed on the rotor core, on a surface of the rotor, or located within a sleeve surrounding the rotor. The rotor can be sized such that an air-gap between the rotor and a stator of a motor using the rotor is a predetermined amount that reduces electromagnetic losses such as eddy current losses.

Abstract: Permanent magnet rotors for electric motors, particularly electric motors for use in compressors, improve the electromagnetic efficiency of the motor. The rotors can include retention of surface permanent magnets using one or more of retaining features on the motor and/or pole spacers interfacing with corresponding features on a rotor core, the use of a monolithic magnet in the rotor, and/or use of a carbon fiber sleeve. The rotor can include an eddy current shield, disposed on the rotor core, on a surface of the rotor, or located within a sleeve surrounding the rotor. The rotor can be sized such that an air-gap between the rotor and a stator of a motor using the rotor is a predetermined amount that reduces electromagnetic losses such as eddy current losses.

Abstract: A method for adjusting compression efficiency for an HVACR system having a variable-frequency drive (VFD) is disclosed. The method includes determining a first compression efficiency, determining an operating point, determining a region of an operating map when a difference between the operating point and a previously determined operating point exceeds a predetermined threshold, adjusting a VFD input to a first input based on the region of the operating map, and controlling the VFD using the first input for a predetermined period of time. The method also includes determining a second compression efficiency and an operation restriction, adjusting the VFD input to a second input based on the operation restriction and a difference between the first compression efficiency and the second compression efficiency, and controlling the VFD using the second input. The method also includes utilizing machine learning control techniques to control several system variables to optimize the compression efficiency.

Abstract: A compressor for a heat transfer circuit includes a variable frequency drive (VFD), an electric motor that rotates a driveshaft, bearing(s) for supporting the driveshaft, a backup gas supply, and a power supply. During a utility power interruption, the backup gas supply operates utilizing DC electrical power generated by a back electromotive force of the electric motor. A method of operating an electric power supply system for a compressor includes operating in a utility power mode and operating in a backup power mode during a utility power interruption. In the utility power mode, AC electrical power is supplied from the VFD to the motor. In the backup power mode, DC electrical power generated in the VFD by a back electromotive force of the motor it used to operate a backup gas supply to supply compressed working fluid to gas bearing(s) of the compressor.

Abstract: A method for adjusting compression efficiency for an HVACR system having a variable-frequency drive (VFD) is disclosed. The method includes determining a first compression efficiency, determining an operating point, determining a region of an operating map when a difference between the operating point and a previously determined operating point exceeds a predetermined threshold, adjusting a VFD input to a first input based on the region of the operating map, and controlling the VFD using the first input for a predetermined period of time. The method also includes determining a second compression efficiency and an operation restriction, adjusting the VFD input to a second input based on the operation restriction and a difference between the first compression efficiency and the second compression efficiency, and controlling the VFD using the second input. The method also includes utilizing machine learning control techniques to control several system variables to optimize the compression efficiency.

Abstract: Permanent magnet rotors for electric motors, particularly electric motors for use in compressors, improve the electromagnetic efficiency of the motor. The rotors can include retention of surface permanent magnets using one or more of retaining features on the motor and/or pole spacers interfacing with corresponding features on a rotor core, the use of a monolithic magnet in the rotor, and/or use of a carbon fiber sleeve. The rotor can include an eddy current shield, disposed on the rotor core, on a surface of the rotor, or located within a sleeve surrounding the rotor. The rotor can be sized such that an air-gap between the rotor and a stator of a motor using the rotor is a predetermined amount that reduces electromagnetic losses such as eddy current losses.

Abstract: Disclosed is a hermetic AC electric motor that includes harmonics shunting such that high frequency harmonics are shunted from the AC electric motor without the use of one or more high frequency filters in the associated motor drive. A related method of operating an AC electric motor includes shunting high frequency harmonics to a fluid passing through the AC electric motor. Also disclosed is a simplified variable speed motor drive system which eliminates the need for a filter for removing high frequency harmonics.

Abstract: Disclosed is a hermetic AC electric motor that includes harmonics shunting such that high frequency harmonics are shunted from the AC electric motor without the use of one or more high frequency filters in the associated motor drive. A related method of operating an AC electric motor includes shunting high frequency harmonics to a fluid passing through the AC electric motor. Also disclosed is a simplified variable speed motor drive system which eliminates the need for a filter for removing high frequency harmonics.

Abstract: Disclosed are an electric motor and a simplified variable speed drive system which renders the use of filtering components in a motor drive circuit unnecessary and increases torque transfer from permanent magnets of the rotor to the output shaft. The motor includes a fluid gap between the rotor and the stator configured to receive a cooling fluid, such a refrigerant. A plurality of radially-abutting, bread loaf-shaped magnets having a flat base are respectively fixed to a plurality of longitudinally oriented mounting facets provided on the shaft to provide maximum torque transfer from the magnets to the shaft. An eddy shield disposed between the faceted shaft and the magnets thermally shunts high frequency harmonics from the magnets to the shaft and cooling fluid. The rotor components are mechanically secured by a sleeve disposed around the rotor.

Abstract: Disclosed are an electric motor and a simplified variable speed drive system which renders the use of filtering components in a motor drive circuit unnecessary and increases torque transfer from permanent magnets of the rotor to the output shaft. The motor includes a fluid gap between the rotor and the stator configured to receive a cooling fluid, such a refrigerant. A plurality of radially-abutting, bread loaf-shaped magnets having a flat base are respectively fixed to a plurality of longitudinally oriented mounting facets provided on the shaft to provide maximum torque transfer from the magnets to the shaft. An eddy shield disposed between the faceted shaft and the magnets thermally shunts high frequency harmonics from the magnets to the shaft and cooling fluid. The rotor components are mechanically secured by a sleeve disposed around the rotor.

Abstract: Disclosed is a hermetic AC electric motor that includes harmonics shunting such that high frequency harmonics are shunted from the AC electric motor without the use of one or more high frequency filters in the associated motor drive. A related method of operating an AC electric motor includes shunting high frequency harmonics to a fluid passing through the AC electric motor. Also disclosed is a simplified variable speed motor drive system which eliminates the need for a filter for removing high frequency harmonics.

Abstract: A somewhat resilient stopper seals the throat of a conventional glass coffee-maker flask and is provided with a pouring passage. The passage is valved by a horizontally swingable blade spring-biased toward its passage-closing position but movable to its passage-opening position by a timer-controlled mechanism. The timer can be set for different time periods by a manually movable member which can either be normally fixed to the timer or be easily removable so that it can be retained at the coffee-making station to insure against purpose-defeating resetting.