Mechanical tubular diaphragm pump features are presented herein. Such a tubular pump can include a resilient tube having a lumen and a pair of upstream and downstream check valves located along the same fluid pathway as the lumen. The tubular pump further includes a motorized reciprocating unit and a depressor configured to be moved by the motorized reciprocating unit to cyclically depress and release the resilient tube. The resilient tube forces fluid within the lumen downstream past the downstream check valve as the resilient tube is depressed by the depressor, and further pulls upstream fluid past the upstream check valve and into the lumen as the resilient tube returns upon release by the depressor. Multiple resilient tubes may be used in the same pump. The tube(s), depressor, and valves may be attached to a housing that is modularly removable from the motorized reciprocating unit.

Controllability of a linear motor or a compressor is improved in a linear motor system that includes: an armature having magnetic poles and winding wires; a mover having a permanent magnet; and a power conversion unit that outputs AC power to the winding wires, in which the mover and the armature are relatively movable, and the mover or the armature is connected to an elastic body. The linear motor system further includes: a position detection unit that detects and outputs the position of the mover with respect to the armature, a position estimation, or a current detection unit that outputs the value of current flowing through the winding wires; and a control unit that controls the output of the power conversion unit on the basis of the output of the position detection unit, the output of the position estimation unit, or the output of the current detection unit.

Systems and methods for controlling a vertical pumping unit are provided. The method includes a self-learning phase and a running phase, wherein the self-learning phase includes obtaining a self-learning result and the running phase includes controlling a motor of the vertical pumping unit to run according to the self-learning result and preset running parameters. The method enables the vertical pumping unit to adjust running parameters of the running phase according to the self-learning results, avoid the accumulation of errors effectively so that changes in stroke length and stroke frequency caused by the motor V-belt, load belt extension and retraction and other elastic links are limited to a minimum range so as to ensure the running accuracy of the vertical pumping unit.

Adaptive control of a Free Piston Mover (1, 19), wherein a Control Parameter Set (COPS′) for closed loop control of a Target Control Variable (CV.sub.t) is adapted using a Future-Stroke Controller (20) to respond to Input Demand (21) signals whilst ensuring a sufficient current control margin and compensating for system changes over time. The Control Parameter Set (COPS′) is transmitted to an In-Stroke Controller (23) in advance of the start of a stroke to be controlled, and the In-Stroke Controller (23) transmits a Current Demand (Qt) to a Current Controller (25) of the Free Piston Mover (119).

A variable displacement reciprocating piston unit includes a sensor probe, a target, a piston having a top dead center position and a bottom dead center position, and a signal processing unit. The sensor probe, the target, and the piston are located in relation to each other so that the target is moved from being absent from the sensor probe to being present at the sensor probe when the piston travels towards the top dead center position, and the target is moved from being present at the sensor probe to being absent from the sensor probe when the piston travels towards the bottom dead center position. The signal processing unit generates a signal indicating a stroke speed and a stroke length of the piston from a signal from the sensor probe indicating a presence and/or an absence of the target as the target moves relative to the sensor probe.

The performance of a solenoid drive liquid pump can be very dependent on the magnitude and stability of an input voltage, with non-ideal input power resulting in loss of efficiency and potential damage to the pump. Pulse width of drive signals provided to the pump, which cause solenoids to alternately energize to move liquid through the pump, may be adjusted in duration in order to compensate for non-ideal input voltage. A drive control module of the pump gathers voltage information, determines an improved pulse width based upon that voltage information, and then provides drive signals based upon the improved pulse width. Operating in this manner, a pump can operate at or near peak efficiency despite both significant variances in input voltage and non-sinusoidal input voltage, and without customized components or adapters.

The invention relates to a method for operating a piston pump (10) which is driven by means of a coil (1) of an electromagnet. A piston (2) of the piston pump (10) can be moved in a cylinder (3) for pumping purposes by means of the electromagnet. A voltage (U) is applied to the coil (1) during a switch-on period such that a current flows through the coil (1) and the piston (2) is accelerated, said voltage being applied by means of an actuation device (11). A time curve of an electric state variable (I, U) of the coil (1) is qualitatively detected, and the curve or a curve derived therefrom is analyzed in order to detect an impact of the piston (2) against a stop. The invention further relates to an actuation device and a piston pump.

The performance of a solenoid drive liquid pump can be very dependent on the magnitude and stability of an input voltage, with non-ideal input power resulting in loss of efficiency and potential damage to the pump. Pulse width of drive signals provided to the pump, which cause solenoids to alternately energize to move liquid through the pump, may be adjusted in duration in order to compensate for non-ideal input voltage. A drive control module of the pump gathers voltage information, determines an improved pulse width based upon that voltage information, and then provides drive signals based upon the improved pulse width. Operating in this manner, a pump can operate at or near peak efficiency despite both significant variances in input voltage and non-sinusoidal input voltage, and without customized components or adapters.

A compressor having a front housing in which a crank chamber is formed. A cylinder block is coupled to an opposite surface facing the front housing and includes reciprocating pistons in a plurality of cylinder bores. A rear housing is coupled to an opposite surface facing the cylinder block, the rear housing includes a suction chamber and a discharge chamber formed therein. A rotating shaft 400 is inserted via centers of the front housing and the cylinder block, the shaft inserted into a swash plate. A diameter maintenance part is configured to constantly maintain a diameter based on an axis direction of the piston 220. A sensor part is configured to sense a speed and a stroke of the piston in accordance with a change in position of a position determination part positioned on one side of the diameter maintenance part.

A liquid feed pump which increases the liquid flow velocity in a stagnation area in the pressure chamber of a plunger pump, thereby improving the liquid replacement speed in the plunger pump. When the liquid in the liquid feed pump is replaced, a first plunger slides back and forth in the space between a lower limit point and an upper limit point, and the second plunger stops at least temporarily at a position near to the upper limit point or slides back and forth for a shorter distance than when the liquid feed pump usually feeds the liquid.