Abstract: A foil bearing assembly includes a cylindrical body that defines a cooling fluid passage between a radial outer surface and a radial inner surface of the cylindrical body. The foil bearing assembly includes a foil bearing retained within the cylindrical body and in thermal communication with the radial inner surface of the cylindrical body. The foil bearing assembly is connectable to a bearing housing such that intake and outlet ports of the foil bearing assembly are connected in fluid communication with a coolant inlet passage and a coolant outlet passage defined by the bearing housing. The foil bearing assembly is interchangeable with a second foil bearing assembly having at least one of a cooling fluid passage, a foil bearing, and a cylindrical body inner diameter different than the corresponding cooling fluid passage, the foil bearing, and the cylindrical body inner diameter of the first foil bearing assembly.

Abstract: A system may include a compressor, a first passageway, a valve and a control module. The compressor includes a compression mechanism operable to compress a working fluid. The first passageway is in fluid communication with an oil sump of the compressor and the compression mechanism. The valve is disposed along the first passageway and movable between an open position allowing lubricant from the oil sump to flow to the compression mechanism and a closed position restricting lubricant from the oil sump from flowing to the compression mechanism. The control module is in communication with the valve and configured to move the valve between the closed position and the open position based on an operating parameter indicative of a temperature of the compression mechanism.

Abstract: A foil bearing assembly includes a cylindrical body that defines a cooling fluid passage between a radial outer surface and a radial inner surface of the cylindrical body. The foil bearing assembly includes a foil bearing retained within the cylindrical body and in thermal communication with the radial inner surface of the cylindrical body. The foil bearing assembly is connectable to a bearing housing such that intake and outlet ports of the foil bearing assembly are connected in fluid communication with a coolant inlet passage and a coolant outlet passage defined by the bearing housing. The foil bearing assembly is interchangeable with a second foil bearing assembly having at least one of a cooling fluid passage, a foil bearing, and a cylindrical body inner diameter different than the corresponding cooling fluid passage, the foil bearing, and the cylindrical body inner diameter of the first foil bearing assembly.

Abstract: A system may include a compressor, a first passageway, a valve and a control module. The compressor includes a compression mechanism operable to compress a working fluid. The first passageway is in fluid communication with an oil sump of the compressor and the compression mechanism. The valve is disposed along the first passageway and movable between an open position allowing lubricant from the oil sump to flow to the compression mechanism and a closed position restricting lubricant from the oil sump from flowing to the compression mechanism. The control module is in communication with the valve and configured to move the valve between the closed position and the open position based on an operating parameter indicative of a temperature of the compression mechanism.

Abstract: An oil balancing system for a multiple compressor system is provided. The oil balancing system includes an oil equalization line disposed between a first compressor and a second compressor. A first solenoid valve is provided in the oil equalization line. A first signal corresponds to a first oil level in the first compressor. A second signal corresponds to a second oil level in the second compressor. An oil balancing module uses the first signal and the second signal to diagnose an oil imbalance between the first compressor and the second compressor, and applies corrective action, whereby the corrective action includes sending control signals to operate at least one of the first compressor, the second compressor, or the first solenoid valve in a way that eliminates the oil imbalance.

Abstract: Systems and methods for compressor unloading detection are provided and include a compressor having a compression mechanism. A controller determines a predicted discharge temperature of the compressor, receives an actual discharge temperature of the compressor, and compares the predicted discharge temperature with the actual discharge temperature. The controller also compares a speed of the compressor with a speed threshold and detects unloading of the compression mechanism based on the comparison of the predicted discharge temperature with the actual discharge temperature and based on the comparison of the speed of the compressor with the speed threshold. The controller performs at least one of generating an alert and a remediating action in response to detecting the unloading of the compression mechanism.

Abstract: A climate-control system may include a compressor and a control module. The compressor includes a motor driving a compression mechanism to compress a working fluid. The control module is in communication with the motor and may be configured to determine a balance speed of the motor at which a forward-rotational inertial force of the compression mechanism is equal to a backward-rotational gas force on the compression mechanism. The control module may be configured to adjust a running speed of the motor to the balance speed after receipt of a compressor-shutdown-command and before shutting down the compressor.

Abstract: Systems and methods for compressor unloading detection are provided and include a compressor having a compression mechanism. A controller determines a predicted discharge temperature of the compressor, receives an actual discharge temperature of the compressor, and compares the predicted discharge temperature with the actual discharge temperature. The controller also compares a speed of the compressor with a speed threshold and detects unloading of the compression mechanism based on the comparison of the predicted discharge temperature with the actual discharge temperature and based on the comparison of the speed of the compressor with the speed threshold. The controller performs at least one of generating an alert and a remediating action in response to detecting the unloading of the compression mechanism.

Abstract: A lubricant management system is provided. The lubricant management system may include a compressor, at least one sensor, and a controller. The compressor may include a lubricant sump, a driveshaft, and a bearing assembly. The compressor may circulate a refrigerant. The lubricant sump may be configured for containing a lubricant. The bearing assembly may be supported by the driveshaft. The at least one sensor may be configured to determine at least one operating condition of the compressor. The controller may be in communication with the at least one sensor to receive the at least one operating condition. The controller may be configured to determine a lubricant film thickness from the at least one operating condition and compare the lubricant film thickness to a threshold lubricant film thickness.

Abstract: Systems and methods for scroll unloading detection are provided and include a scroll compressor having a scroll compression mechanism. A controller determines a predicted discharge temperature of the scroll compressor, receives an actual discharge temperature of the scroll compressor, and compares the predicted discharge temperature with the actual discharge temperature. The controller also compares a speed of the scroll compressor with a speed threshold and detects unloading of the scroll compression mechanism based on the comparison of the predicted discharge temperature with the actual discharge temperature and based on the comparison of the speed of the scroll compressor with the speed threshold. The controller performs at least one of generating an alert and a remediating action in response to detecting the unloading of the scroll compression mechanism.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. The drive controller includes a speed control module that controls the drive circuit to rotate the motor at a requested speed. The drive controller includes a speed determination module that generates the requested speed. The drive controller includes a defrost module that enables a defrost mode in response to a defrost command. While the defrost mode is enabled, the defrost module causes the speed determination module to (i) ramp the requested speed down from a speed demand to a defrost speed and (ii) maintain the requested speed at the defrost speed for a predetermined period of time.

Abstract: Systems and methods for scroll unloading detection are provided and include a scroll compressor having a scroll compression mechanism. A controller determines a predicted discharge temperature of the scroll compressor, receives an actual discharge temperature of the scroll compressor, and compares the predicted discharge temperature with the actual discharge temperature. The controller also compares a speed of the scroll compressor with a speed threshold and detects unloading of the scroll compression mechanism based on the comparison of the predicted discharge temperature with the actual discharge temperature and based on the comparison of the speed of the scroll compressor with the speed threshold. The controller performs at least one of generating an alert and a remediating action in response to detecting the unloading of the scroll compression mechanism.

Abstract: A climate-control system may include a compressor and a control module. The compressor includes a motor driving a compression mechanism to compress a working fluid. The control module is in communication with the motor and may be configured to determine a balance speed of the motor at which a forward-rotational inertial force of the compression mechanism is equal to a backward-rotational gas force on the compression mechanism. The control module may be configured to adjust a running speed of the motor to the balance speed after receipt of a compressor-shutdown-command and before shutting down the compressor.

Abstract: A system includes a plurality of compressors, an evaporator, an expansion device, and a system controller. The compressors may be linked in parallel. The system controller may: determine a saturated evaporator temperature, a saturated condensing temperature, and a target capacity demand; determine an estimated system capacity and an estimated power consumption for each compressor operating configuration; compare the estimated system capacity with the target capacity demand and an error tolerance value; select an optimum operating mode based on the comparisons and based on the estimated power consumption; and command activation and deactivation of the plurality of compressors to achieve the selected optimum operating mode. The optimum operating mode may be selected after the normal system logic achieves a steady state and may be selected from a group having the estimated system capacity within the error tolerance of the target capacity demand and a lowest associated power consumption value.

Abstract: An oil balancing system for a multiple compressor system is provided. The oil balancing system includes an oil equalization line disposed between a first compressor and a second compressor. A first solenoid valve is provided in the oil equalization line. A first signal corresponds to a first oil level in the first compressor. A second signal corresponds to a second oil level in the second compressor. An oil balancing module uses the first signal and the second signal to diagnose an oil imbalance between the first compressor and the second compressor, and applies corrective action, whereby the corrective action includes sending control signals to operate at least one of the first compressor, the second compressor, or the first solenoid valve in a way that eliminates the oil imbalance.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. A speed control module controls the drive circuit to rotate the motor at a requested speed. A speed determination module generates the requested speed based on a speed demand from a system controller. A lost rotor control module identifies a lost rotor condition and, in response to identifying the lost rotor condition, instructs the speed determination module to set the requested speed to an override speed that is lower than the speed demand. The lost rotor control module identifies the lost rotor condition in response to a comparison of a speed error with an adaptive threshold. The speed error is based on a difference between requested and estimated speeds of the motor. During first and second system states, the adaptive threshold is set to first and second thresholds, respectively.

Abstract: A lubricant management system is provided. The lubricant management system may include a compressor, at least one sensor, and a controller. The compressor may include a lubricant sump, a driveshaft, and a bearing assembly. The compressor may circulate a refrigerant. The lubricant sump may be configured for containing a lubricant. The bearing assembly may be supported by the driveshaft. The at least one sensor may be configured to determine at least one operating condition of the compressor. The controller may be in communication with the at least one sensor to receive the at least one operating condition. The controller may be configured to determine a lubricant film thickness from the at least one operating condition and compare the lubricant film thickness to a threshold lubricant film thickness.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. A speed control module controls the drive circuit to rotate the motor at a requested speed. A speed determination module generates the requested speed based on a speed demand from a system controller. A lost rotor control module identifies a lost rotor condition and, in response to identifying the lost rotor condition, instructs the speed determination module to set the requested speed to an override speed that is lower than the speed demand. The lost rotor control module identifies the lost rotor condition in response to a comparison of a speed error with an adaptive threshold. The speed error is based on a difference between requested and estimated speeds of the motor. During first and second system states, the adaptive threshold is set to first and second thresholds, respectively.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. The drive controller includes a speed control module that controls the drive circuit to rotate the motor at a requested speed. The drive controller includes a speed determination module that generates the requested speed. The drive controller includes a defrost module that enables a defrost mode in response to a defrost command. While the defrost mode is enabled, the defrost module causes the speed determination module to (i) ramp the requested speed down from a speed demand to a defrost speed and (ii) maintain the requested speed at the defrost speed for a predetermined period of time.

Abstract: A drive controller for a motor of a compressor includes a drive circuit that applies voltages to windings of the motor. The drive controller includes a speed control module that controls the drive circuit to rotate the motor at a requested speed. The drive controller includes a speed determination module that generates the requested speed. The drive controller includes a locked rotor protection module that identifies a locked rotor condition and, in response to identifying the locked rotor condition, instructs the speed determination module to power down the motor. The locked rotor protection module acquires an estimated speed of the motor upon expiration of a predetermined time interval that begins upon startup of the motor. The locked rotor protection module identifies the locked rotor condition in response to the estimated speed being lower than a threshold speed. The threshold speed is based on the requested speed.