A refrigeration apparatus includes a compressor connected to a refrigerant circuit, and a bearing monitor. The compressor includes a compression mechanism, an electric motor, a drive shaft, and a plain bearing that supports a journal portion of the drive shaft. The bearing monitor performs an abnormal-state operation to cope with poor lubrication on the plain bearing if an abnormal state condition is satisfied. The abnormal state condition is a condition indicating that a rate of change of current exceeds a first reference value. The rate of change of current is an amount of change in a driving current usable to drive the compressor per unit time. The journal portion of the drive shaft has a surface roughness of at least 0.05 μm.

A control device is provided for controlling a rotation speed of an electric oil pump, including a motor and a pump mechanism connected to the motor, based on a command value input from a host device. The control device includes: a first calculator calculating a first duty value of current to be output to the motor based on a deviation between the command value and a rotation speed of the motor; a second calculator calculating a second duty value of current to be output to the motor based on a deviation between a current limit value of the motor and a current value of the motor; and a drive current determiner comparing the first duty value calculated by the first calculator and the second duty value calculated by the second calculator, and selecting the lower duty value as a duty value of current that drives the motor.

A compressed air system for a motor vehicle with an air supply system includes an electric drive motor, which can be controlled for variable speed, an air compressor coupled to be driven by the electric drive motor, an electric power supply for supplying electric power to the electric drive motor, at least one air reservoir connected with the air compressor to receive air from the air compressor, an air utilization system connected to the air reservoir to receive air from the air reservoir, and a controller to control the speed of the electric drive motor. The controller controls the electric drive motor to determine its speed depending upon at least one of the following signals: a signal representing the activation status of an accelerator pedal of the vehicle, a signal representing the speed of the vehicle, a signal representing the temperature of the power supply, a signal representing the temperature of the electric drive motor, a signal representing the wetness level of the air compressed by the air compressor, a signal representing the load of the air compressor, a signal representing the running time of the air compressor, or a signal representing the status of the electric power supply.

A system comprising: a reservoir (14) for holding a liquid; a pump (20) arranged to pump the liquid out of the reservoir (14) or into the reservoir (14); a level sensor (26) configured to detect the level of the liquid in the reservoir (14) and to generate level data; a current monitor (28) configured to monitor the current drawn by the pump (20) and to generate current data; and a controller (30) configured to: receive level data and determine the static head from the level data, and generate head data from the static head; receive first current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a first period of operation of the pump (20); receive second current and head data corresponding to the current drawn by the pump (20) as a function of the static head for a second period of operation of the pump (20), wherein the second current and head data is recorded when the liquid in the reservoir (14) is between a first liquid level and a second liquid level, and wherein the first current and head data is recorded when the liquid in the reservoir (14) is between at least the first liquid level and the second liquid level; and process the first current and head data and the second current and head data to determine first difference data (PPI) representing the difference between the current drawn between the first liquid level and the second liquid level in the first period of operation and the second period of operation, the first difference data providing a pump performance indicator giving an indication of the condition of the pump.

A method for the weight-dependent control of the internal pressure of a supporting body loaded by a weight load or payload, wherein the internal pressure is produced by means of an electric-motor-driven compressor, and the weight load or payload which is present and which acts on a supporting body in the form of a mass m.sub.Load under the effect of acceleration due to gravity g is determined in that a reduction and a subsequent increase in the internal pressure take place, wherein the increase in the internal pressure causes the position of an application point of the weight load or payload to change by a position difference Z, wherein:

during the increasing of the internal pressure by means of the compressor, the motor current I.sub.Load of the drive motor of the compressor is measured with a constant motor voltage U and integrated over the time of the increase in pressure, and the electrical work W.sub.Load which is necessary for the change in position is determined therefrom,

wherein the electrical work W.sub.Load the electrical work W.sub.Load is compared with a characteristic value of the electrical work W.sub.0 from a characteristic diagram, wherein the change in position Z, the difference in mass m and the difference in payload F.sub.Z are determined from the difference W between W.sub.Load and W.sub.0 and the mass m.sub.Load and the weight load or payload which is actually present as a result is determined therefrom.

Method for protecting an electric motor of a motor driven consumer equipped with a controller for controlling the capacity or the power of the consumer, comprises the following steps: the determination of the thermal condition of the motor by direct measurement on the motor; and the limitation of the maximum capacity or the maximum power of the consumer as a function of the aforementioned determined thermal condition.

A monitoring and control apparatus communicates with an electrical drive of a subsurface artificial lift system to identify, predict and mitigate against failure of the artificial lift system. A monitoring and control apparatus: reads torque signals from the electrical drive or from a measurement device, produces a filtered torque signal; identifies frequency components of the filtered torque signal; compares the frequency components of the filtered torque signal with frequency components of a reference torque signal indicative of a healthy state of a pump motor of the artificial lift system to identify harmful frequencies in the filtered torque signal and generate a failure prediction index representing the likelihood of failure in comparison to a stable operation status; and then send a control signal to the electrical drive to adjust a frequency response of the pump motor so that the identified harmful frequency component is dampened.

An apparatus and method is disclosed to monitor the operating condition of a rotational electromechanical system and to further sense and diagnose an abnormal condition of such systems in real time. The apparatus and method includes an improved technique of monitoring such systems, detecting problems, diagnosing causes and acting on the problems to reduce failures and increase production.

The present invention provides wireless sensor technology seamlessly integrated into a pump system having a pump, a motor and a drive, has diagnostic and prognostic intelligence that utilizes sensor data, allows real-time condition monitoring; enables easy access to data and analytics via smart devices (i.e., smart phones and tablets); allows for easy remote monitoring (i.e., web portal) of the pump system; allows self-learning artificial intelligence (AI) built-in that adapts to changing conditions; and allows for smart pump system remote control. In operation, the present invention monitors the health and performance of the pump system that allows the user to get real-time data and intelligence virtually anywhere and anytime, as well as real-time diagnostics and prognostics, and also allows for smart control of the pump system remotely via smart device, and reduces downtime of equipment.

A flow system includes a pump, a motor connected to the pump that drives the pump and draws electrical energy and a sensor that measures the electrical energy drawn by the motor. The system also includes a control module for the flow system. The control module configured to perform a control module method that includes: receiving electrical data from the sensor; receiving operating characteristic data of the pump from one or more pump sensors; comparing the changes in the electrical data over time to the operating characteristic data; and determining a health of the pump on the comparison of changes in the electrical data over time to operating characteristic data.