Disclosed herein are methods of pumping fluids and fluid pump devices and systems. The systems described herein include an adjustable pump configured to expel fluid at a plurality of flow rates. The systems include at least one current measurement device communicatively coupled to the pump and configured to measure an electrical current applied to the pump. The systems include a controller communicatively coupled to the pump and the at least one current measurement device. The controller is configured to adjust an operating parameter of the pump based at least in part on a measurement of the electrical current measured by the at least one current measurement device.

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 high pressure pump including a linear actuator having a servo motor to axially rotate a hollow rotor shaft in alternating directions, the servo motor having a stator positioned co-axially around the hollow rotor shaft with an interior of the rotor shaft being co-axially coupled to a drive member to convert axial rotation into reciprocal displacement, the drive member being constrained against linear movement and supporting a shaft. At least one piston is coupled to the shaft and the piston is arranged within a cylinder to define a pumping chamber, whereby alternating rotation of the rotor shaft causes reciprocal linear displacement of the piston to pressurize fluid in the pumping chamber. A drive mechanism includes a controller coupled to a servomotor and an encoder to measure movement of the hollow rotor or output shaft and send a feedback signal proportional to the movement to the controller.

A light load abnormality determination method for an electric oil pump (3) that circulates oil to an object to be cooled by the electric oil pump driven by a motor (11), the method comprising: a detection step (41) to detect a current flowing through the motor, a voltage supplied to the motor, and a rotation speed of the motor; a calculation step (42) to calculate a piping resistance equivalent value or a reciprocal value of the piping resistance equivalent value, as a load evaluation value for light load abnormality determination, based on the current, the voltage and the rotation speed detected by the detection step; and a light load abnormality determination step (44) to determine a light load abnormality of the electric oil pump based on the load evaluation value.

Electrically driven mobile compressor or pump, comprising at least one compressor element or pump element for supplying a pressurised fluid to a network of consumers of such pressurised fluid; an electric drive motor with a variable speed control coupled to the compressor element or pump element and a controller for the variable speed control of the electric drive motor as a function of the flow rate of compressed gas and/or pressure demanded by the network, and a connection for connection of the compressor or pump to an electricity supply source, and the controller is provided with an algorithm with which the electric current drawn from the supply source can be limited to a set or adjustable maximum value by controlling the speed.

A high pressure pump including a linear actuator having a servo motor to axially rotate a hollow rotor shaft in alternating directions, the servo motor having a stator positioned co-axially around the hollow rotor shaft with an interior of the rotor shaft being co-axially coupled to a drive member to convert axial rotation into reciprocal displacement, the drive member being constrained against linear movement and supporting a shaft. At least one piston is coupled to the shaft and the piston is arranged within a cylinder to define a pumping chamber, whereby alternating rotation of the rotor shaft causes reciprocal linear displacement of the piston to pressurize fluid in the pumping chamber. A drive mechanism includes a controller coupled to a servomotor and an encoder to measure movement of the hollow rotor or output shaft and send a feedback signal proportional to the movement to the controller.

A compressor driving apparatus, or a home appliance including the same, includes a DC terminal capacitor to store a charge, an inverter to convert direct current associated with the charge of the DC terminal capacitor into an alternating current and output the alternating current to a motor, an output current detection unit to detect an output current flowing in the motor, and an inverter controller to increase a motor speed by starting the motor, and controlling a speed increase of the motor to change based on an increasing slope of a change in an output current detected by the output current detection unit during the speed increase of the motor.

A high pressure pump including a linear actuator having a servo motor to axially rotate a hollow rotor shaft in alternating directions, the servo motor having a stator positioned co-axially around the hollow rotor shaft with an interior of the rotor shaft being co-axially coupled to a drive member to convert axial rotation into reciprocal displacement, the drive member being constrained against linear movement and supporting a shaft. At least one piston is coupled to the shaft and the piston is arranged within a cylinder to define a pumping chamber, whereby alternating rotation of the rotor shaft causes reciprocal linear displacement of the piston to pressurize fluid in the pumping chamber. A drive mechanism includes a controller coupled to a servomotor and an encoder to measure movement of the hollow rotor or output shaft and send a feedback signal proportional to the movement to the controller.

A method for determining a pressure value in a fluid conveying system of a motor vehicle, the vehicle having an actuable electric motor and having a fluid feed pump drivable by the electric motor, includes: determining a rotational speed of the electric motor; determining an actuation current of the electric motor; acquiring a pressure value as a function of the determined rotational speed and the determined actuation current of the electric motor; processing the acquired pressure value with at least one external state variable in a controller; and correcting the acquired pressure value.

A system for circulating a liquid which comprises at least one pump, connectable to at least one pipe for the flow of a liquid and driven by at least one electric motor; sensors being provide for sensing at least two electrical parameters correlated with the operation of the electric motor and a processor which is functionally connected to the sensors and configured to determine, based on the signals provided by the sensors, at least one fluid-dynamic parameter correlated with the flow of the liquid through the pipe.