A fluid-driven actuator system includes a fluid-driven actuator and at least one proportional control valve and at least one pump connected to the fluid-driven actuator to provide fluid to operate the fluid-driven actuator. The at least one pump includes at least one fluid driver having a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from the pump inlet to the pump outlet. The fluid driven actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to adjust at least one of a flow in the fluid system to a flow set point and a pressure in the fluid system to pressure set point and a concurrently establishes an opening of the at least one proportional control valve to adjust at least one of the flow to the flow set point and the pressure to the pressure set point.

A method for controlling the speed of a compressor with a controller as a function of the available gas flow. The method includes the steps of setting a desired value for the inlet pressure; determining the inlet pressure; and determining the speed. The method further includes controlling the speed of the compressor by reducing or increasing it depending on whether the inlet pressure is less than or greater than a set desired value until the inlet pressure is equal to the set desired value where the characteristic data of the compressor relating to the efficiency and/or the Specific Energy Requirement (SER) as a function of the speed and the inlet pressure is provided and the desired value of the inlet pressure is adjusted on the basis of the aforementioned characteristic data so that the efficiency of the compressor is a maximum or the SER is a minimum.

A method is for surveillance of an operating state of a pumping device connected to a process chamber in order to determine a failing operating state of the pumping device. The pumping device includes at least one rough-vacuum pump including a motor for driving the rough-vacuum pump and a variable speed drive to control the rotation speed of the motor, to receive a first input parameter corresponding to a set point frequency and a second input parameter corresponding to a motor current, and to deliver to the motor an output parameter corresponding to a control frequency. A failing operating state is determined when in steady-state operation the difference between the first input parameter and the output parameter is equal to or exceeds 10% of the first input parameter for a predetermined time greater than 3 seconds. The method can be implemented in a pumping device and an installation.

A method of operating a compressor includes obtaining a mechanical angle and an angular speed of a rotor, determining an amplitude of a fundamental harmonic of a periodic load torque exerted on the rotor based at least in part on the mechanical angle and a harmonic series representation of the periodic load torque, obtaining a speed error by subtracting the angular speed from a reference angular speed, determining a DC component of the periodic load torque based at least in part on a speed error and a closed loop feedback control algorithm, calculating an electromagnetic torque using the DC component of the periodic load torque and the amplitude of the fundamental harmonic of the periodic load torque, and operating the electric motor to generate the calculated electromagnetic torque on the rotor.

The present invention provides a method of ceasing rotation of a rotor of a vacuum pump. The method comprises the steps of rotating the rotor at an intermediate RPM, at which there is substantially no probability of the rotor clashing with the stator, for a dwell time sufficient for the vacuum pump to be at or below a threshold temperature, and subsequently coasting down the rotation of the rotor until cessation of rotation.

A hydraulic fluid system is disclosed herein. The hydraulic fluid system includes a hydraulic motor including an output shaft, a reduction gear box having a first side and an opposing second side, the reduction gear box being coupled to the output shaft at the first side and coupled to a reduction shaft at the second side, and a magneto-rheological fluid brake (MRF) brake coupled to the reduction shaft.

A control device that controls a target vacuum pump including a motor, including: a decision unit that decides, using at least one of target state quantities at a time of a past stop process of the target vacuum pump or another vacuum pump wherein the target state quantities are state quantities which fluctuate in accordance with a load at a time of a process of stopping a vacuum pump, a normal fluctuation range or a normal time fluctuation behavior of the target state quantity at the time of the stop process; and a control unit that controls the motor, wherein the control unit compares the target state quantity at the time of the process of stopping the target vacuum pump with the normal fluctuation range or the normal time fluctuation behavior, and changes a method of controlling the motor during the stop process depending on the comparison result.

A rotary-vane internal combustion engine of the cat and mouse or scissor type with coordinated rotation of two co-axial shafts with position sensors creating chambers of variable volume for intake, compression, power and exhaust strokes. A reversible electric generator motor on at least one of the shafts with an electronic control system for current, an energy storage unit and electrical load. The total work done and angular speed is calculated or empirically determined while an alternating accelerating or decelerating torque is applied for a continuous, uniform rotation cycle.

The control section controls the electric motor to be driven such that the number of revolutions becomes equal to the target number of revolutions. If the control section sets the target number of revolutions to a number of revolutions of the electric motor requested by another control section, the control section changes the number of revolutions of the electric motor at an increase rate lower than or equal to the upper limit value of the increase rate or at a decrease rate lower than or equal to the upper limit value of the decrease rate. If the control section sets the target number of revolutions to a number-of-revolutions limit value, which is determined based on the voltage of a vehicle battery, the control section is able to decrease the number of revolutions of the electric motor at a decrease rate exceeding the upper limit value.

A method, system, and computer-readable medium related to control of mud motors in drilling systems, of which the method includes measuring an eccentricity of rotation of a rotor in a stator of a mud motor using a rotor-position sensor, determining a torque of the mud motor based in part on the eccentricity, and selecting a fluid flow rate, a pressure, or both of fluid delivered downhole, through the mud motor, based in part on the determined torque.