A pump device includes a flow control valve that returns a part of working fluid discharged from a pump to the suction side, and the flow control valve includes a valve body, a first fluid pressure chamber that is provided so as to face against a first-side end surface of the valve body and that is communicated with a discharge channel, a second fluid pressure chamber that is provided so as to face against a second-side end surface of the valve body and that is communicated with the discharge channel, a biasing member that is accommodated in the second fluid pressure chamber for biasing the valve body in the valve-closing direction, and a pressure regulator that is provided in a communicating passage through which the discharge channel is communicated with the second fluid pressure chamber and that adjusts pressure in the second fluid pressure chamber.

A fuel supply device according to the present invention comprises a first fuel pump for forcing fuel from a fuel tank to a fuel passage, a first electric motor for driving the first fuel pump, a second fuel pump for forcing fuel from the fuel tank to the fuel passage, a second electric motor for driving the second fuel pump, a supply flow rate sensor for detecting flow rate in the supply passage, and a control device for controlling the flow rate in the supply passage to follow a desired value thereof, by regulating rotational speeds of the first and second electric motors depending on a difference between the desired value and a detected value of flow rate in the supply passage.

A progressing cavity pump operated by a motor is provided. In one embodiment, a system includes a motor, a progressing cavity pump having a rotor and a stator, and a fluid coupling that connects the motor to the progressing cavity pump. The fluid coupling includes an input turbine and an output turbine disposed within a housing. The motor is connected to the input turbine of the fluid coupling and the rotor of the progressing cavity pump is connected to the output turbine of the fluid coupling to enable the progressing cavity pump to be operated by the motor via the fluid coupling to pump fluid through the progressing cavity pump. Additional systems, devices, and methods are also disclosed.

A progressing cavity pump operated by a motor is provided. In one embodiment, a system includes a motor, a progressing cavity pump having a rotor and a stator, and a fluid coupling that connects the motor to the progressing cavity pump. The fluid coupling includes an input turbine and an output turbine disposed within a housing. The motor is connected to the input turbine of the fluid coupling and the rotor of the progressing cavity pump is connected to the output turbine of the fluid coupling to enable the progressing cavity pump to be operated by the motor via the fluid coupling to pump fluid through the progressing cavity pump. Additional systems, devices, and methods are also disclosed.

There is disclosed a pump apparatus which can more accurately determine the occurrence of an abnormal vibration. The pump apparatus includes: a pump; an electric motor for driving the pump; an inverter as a speed changing means for the electric motor; a vibration detector for detecting at least one of a vibration of the pump, a vibration of the electric motor and a vibration of the inverter; and a controller for controlling the pump. The controller includes a storage unit for storing a measured vibration value measured by the vibration detector. The storage unit has a storage table which, when the rotational speed of the pump is increased stepwise to a predetermined rotational speed, stores the measured vibration value measured at each step.

A method for conveying a fluid through a screw pump, wherein at least one drive spindle of the screw pump is driven by an asynchronous motor, wherein, the asynchronous motor is operated at a first nominal frequency, a gas/liquid mixture being conveyed as fluid, a measurable variable depending on a liquid content of the fluid is registered, and after a fulfillment of a frequency-change condition depending on the measurable variable the asynchronous motor is operated at a second nominal frequency, reduced in comparison with the first nominal frequency.

A progressive cavity pump (PCP) system includes a PCP with a rotor rotatably disposed in a stator, a permanent magnet motor, sucker rod(s), and a control system. The rotor is coupled to one of the sucker rods via a high-torque connection that allows for counter clockwise rotation without loosening the connection between the rotor and sucker rod. The control system operates the system in a production mode by rotating the rotor clockwise. Upon manual input by a user, or automatic triggering when protections settings of the control system call for a shutdown or cleanout or when the control system senses an imminent pump shutdown, the control system operates the system in a reverse mode by rotating the rotor counterclockwise. The reverse mode pumps fluids and suspended solid particles down into the well prior to pump shutdown to inhibit the solids from clogging the pump or preventing the pump from restarting.

A progressive cavity pump (PCP) system includes a PCP with a rotor rotatably disposed in a stator, a permanent magnet motor, sucker rod(s), and a control system. The rotor is coupled to one of the sucker rods via a high-torque connection that allows for counter clockwise rotation without loosening the connection between the rotor and sucker rod. The control system operates the system in a production mode by rotating the rotor clockwise. Upon manual input by a user, or automatic triggering when protections settings of the control system call for a shutdown or cleanout or when the control system senses an imminent pump shutdown, the control system operates the system in a reverse mode by rotating the rotor counterclockwise. The reverse mode pumps fluids and suspended solid particles down into the well prior to pump shutdown to inhibit the solids from clogging the pump or preventing the pump from restarting.

A method controls the start-up of an oil pump of a gearbox by a brushless electric motor that has no position sensor. The stator coils are powered from the off mode in a constant-current open-loop control sequence until the pump reaches a speed threshold at which speed regulation switches over to closed-loop control on a setpoint corresponding to the lubrication flow rate required to ensure the reliability of the gearbox, but without in so doing exceeding a current threshold indicative of pump seizure, at which point motor control switches back over to the constant-current open-loop control sequence. The open-loop current setpoint is higher than the threshold for switching over to closed-loop control so that in the open-loop control mode the motor torque available at the pump is higher than in the closed-loop control mode.

A method for controlling a recirculation pump assembly is disclosed. The method includes receiving a process-dependent characteristic and determining a recirculation flow rate of adhesive that flows to the recirculation pump assembly based on the process-dependent characteristic. The method further includes determining a recirculation pump speed of the recirculation pump assembly for pumping the adhesive to a supply channel using the recirculation flow rate, and adjusting an operating speed of the recirculation pump assembly to match the recirculation pump speed. A system and storage device for performing the above method are also disclosed.