The invention relates to a method for operating a piston pump, which is driven by means of a coil (1) of an electromagnet, wherein a piston (2) of the piston pump can be moved against a restoring force by means of the electromagnet, wherein a voltage (U) is applied to the coil (1) during a switch-on duration such that a current (I) flows through the coil (1) and the piston (2) is accelerated, wherein two different quenching methods are used for the current (I) in the coil (1).

A piston compressor containing a housing with a compression chamber in it, having an inlet and an outlet and a piston arranged movably back and forth in an axial direction in the compression chamber between an upper dead point and a lower dead point, delimited by a kinematic mechanism with which the piston is connected. The drive is formed exclusively by an electromagnetic linear drive of the piston.

Systems and methods for operating a linear motor (e.g., for an ESP), where the motor's mover moves in a reciprocating motion within a bore of the stator. Hard stops are located at the ends of the bore. The motor has a first set of sensors in the stator positioned proximate to the bore. When the mover moves in the bore, the sensors produce corresponding output signals, except when the mover is in a position near, but not in contact with a hard stop. While the sensors produce output signals, the motor is driven in a first direction toward the hard stop. When the sensors stop producing the output signals, the mover has reached the first position, and the motor is controlled to reverse the direction of the mover.

A method of displacing fluid includes pulling a pump displacement member through a suction stroke with a pull, the pull configured to transmit only tensile forces to the fluid displacement member. A working fluid disposed in an internal pressure chamber drive the fluid displacement member through a pumping stroke. The pull is prevented from transmitting any compressive forces to the fluid displacement member, such that the pull does not drive the fluid displacement member through the pumping stroke.

An example linear pumping system suitable for small size and low flow rate operation. The system includes a pump casing that encloses a linear motor and one or two (an upper and lower) pumps. The pump casing may include an upper fluid inlet port, a lower fluid inlet port, and a fluid-outlet port. The linear motor includes a stator and a mover, where the mover includes an upper plunger portion and a lower plunger portion and is configured to move alternately up and down relative to the stator. The upper and lower pumps positioned on both sides of the mover may each include a pump chamber, a fluid inlet valve, and a fluid outlet valve. In operation, hydraulic pressure from the upper and lower pump outlet valves causes fluid within an interior cavity of the pump casing to be expelled through the fluid outlet port. The motion of the mover can be controlled using pressure and/or plunger position measurements.

A metering pump enables simple fluid metering, has an extended service life, and is of compact construction. The metering pump includes a piston rod in operative connection with a control body which has a circumferential sealing zone, in that the internal circumference of the sealing cylinder radially surrounds the sealing zone. On the piston rod side, a compensating zone, which is at a greater radial distance from the sealing cylinder than the sealing zone, adjoins the sealing zone at least in portions, and in that the control body, after passing beyond the control edge in the actuation direction of the actuator, at least largely severs the fluid connection.

A fully submergible dual-action cryogenic pump has a housing configured to receive a liquid into the interior compartment when submerged in the liquid. The housing includes an interior compartment having an inner peripheral surface, a first end, and a second end. A free piston having a first end, a second end, and an outer peripheral surface is contained within the interior compartment. A first compression chamber is formed between the first end of the free piston and the first end of the interior compartment. A second compression chamber is formed between the second end of the free piston and the second end of the interior compartment. An electromagnetic drive is configured to reciprocate the free piston. A sealing area is formed by the outer peripheral surface of the free piston sealing with the inner peripheral surface of the interior compartment.

A positive displacement inductive pump includes a central piston formed of a ferromagnetic material having non-ferromagnetic end pistons that extend from each of its opposite ends. Stationary end walls are mounted to opposite ends of a housing and are centrally bored. First and second inductive coils are alternately energized, causing the central piston and the end pistons to conjointly reciprocate within an axial bore and the end wall central bores, respectively. First and second check valves are positioned outboard of each end wall and allow valve-controlled ingress and egress of material into and out of the axial and central bores. The relative diameters of the central piston and the end pistons are changed to control the relationship between the magnetic force applied and the output pressure for a given volume of fluid.

A fluid flow meter comprising a fluid pump to displace fluid with pumping strokes of one or more pumping stroke types wherein each of the one or more stroke types displaces a known volume of fluid, a sensor functionally associated with a fluid reservoir and adapted to generate a signal indicative of a fluid pumping condition within the fluid reservoir, which fluid reservoir is integral or functionally associated with the pump, and circuitry to trigger one or a sequence of strokes of the pump in response to a signal from the sensor.

A system for monitoring flow conditions of fluid flowing from a product container through a solenoid pump. The system includes at least one solenoid pump comprising a solenoid coil, which, when energized, produces a stroke of the solenoid pump, at least one product container connected to the at least one solenoid pump wherein the at least one solenoid pump pumps fluid from the at least one product container during each stroke, at least one PWM controller configured to energize the at least one solenoid pump, at least one current sensor for sensing the current flow through the solenoid coil and producing an output of the sensed current flow, and a control logic subsystem for controlling the flow of fluids through the solenoid pump by commanding the PWM controller and for monitoring the current through the solenoid pump by receiving the output from the current sensor, wherein the control logic subsystem uses the measured current flow through the solenoid coil to determine whether the stroke of the solenoid pump is functional.