The lubricant level within a reservoir is difficult to monitor, leading to the reservoir being refilled more often than necessary to ensure that the reservoir always contains lubricant. A lubricant level sensing system is connected to and monitors various aspects of the pump assembly that draws lubricant from the reservoir. The pump assembly displaces a known volume of lubricant with each pump stroke. A lubricant-level estimator calculates an estimated lubricant level remaining in the reservoir based on a stroke-count value as sensed from the pump assembly and on a reference value stored in a memory. The estimated lubricant level provides the lubricant remaining and the rate of usage such that maintenance can be scheduled ahead of time to prevent the reservoir running dry.

A controller for operating a rod pumping unit at a pump speed. The controller includes a processor configured to operate a pump piston of the rod pumping unit at a first speed. The processor is further configured to determine a pump fillage level for a pump stroke based on a position signal and a load signal. The processor is further configured to reduce the pump speed to a second speed based on the pump fillage level for the pump stroke.

A monitoring system for a plurality of pressure pumps may include, for each pump, a strain gauge, a position sensor and a pressure transducer. A strain gauge may be positionable on each pump to generate a strain measurement corresponding to strain in each pump. A position sensor may be positionable on each pump to generate a position measurement corresponding to a position of a rotating member corresponding of each pump. A pressure transducer is positionable on each pump to generate a boost pressure measurement that is usable with the strain measurement and the position measurement to determine a cavitation threshold for each pump.

The present disclosure provides a method and system for delivering a high-viscosity fluid 300. In an example, a reciprocating a piston pumps a high-viscosity fluid 300 through a one-way check valve 130 into a pump chamber 125. Responsive to receipt of a request for a dose of the high-viscosity fluid 300, an output valve 135 in the pump chamber 125 is opened, and the piston is reciprocated in order to eject a dose of the high-viscosity fluid 300 from the pump chamber 125 through the output valve 135.

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.

A monitoring system can include a position sensor coupled to a pump to sense a position of a rotating assembly member of the pump and generate an associated position signal. The position signal can be used to determine a position of a displacement member in a chamber in a fluid end of the pump. The monitoring system can include a strain gauge to measure strain in the chamber and generate an associated strain signal. The strain signal can be used to determine an actuation point for a valve in the chamber. A computing device can determine an actuation delay of the valve by correlating the position of the displacement member in the chamber with the actuation point for the valve. The actuation delay can represent the actuation point relative to the position of the displacement member during operation of the pump.

Method, and associated system, computer program and use, of controlling working range of a pump bellows, including maximum limitations such as maximum retracting position and maximum extension position of the bellows, the method comprising the steps of: a) reading at least a first position of a bellows (6′, 6″) in a closed hydraulic loop volume using at least one position sensor (12′, 12″), g) transmitting a first position signal representing the first position to a control system, h) wherein the control system, based on the at least first position signal: c1) determines the position of the bellows (6′, 6″) represented by the at least first position signal, c2) compares the position of the bellows (6′, 6″) with a predetermined bellows position operating range, and c3) if the position is outside the predetermined bellows position operating range, instructs an oil management system valve (16′, 16″) allowing a dual acting pressure boosting liquid partition device (2) to recalibrate the hydraulic fluid volume in the closed hydraulic loop volume to re-establish a hydraulic fluid volume that causes the at least first position to return to a position within the predetermined bellows position operating range.

A rolling diaphragm pump that can inhibit an increase in cost with a simple configuration is provided. A rolling diaphragm pump 1 includes: a housing 2; a piston 3 disposed so as to be slidable relative to an inner peripheral surface of the housing 2 and reciprocatable in an axial direction; a rolling diaphragm 4 having a movable portion 41 disposed at one end portion in the axial direction of the piston 3 and reciprocatable together with the piston 3, a fixed portion 42 fixed to the housing 2, and a flexible connecting portion 43 connecting the movable portion 41 and the fixed portion 42 to each other; a pump chamber 5 defined by the rolling diaphragm 4 at one side in the axial direction within the housing 2 and into and from which a transport fluid is sucked and discharged by changing a volume of an interior of the pump chamber 5 by deformation of the connecting portion 43 due to reciprocation of the piston 3; and a working fluid chamber 6 defined by another end portion in the axial direction of the piston 3 at another side in the axial direction within the housing 2 and into and from which a working fluid is supplied and discharged, thereby causing the piston 3 to reciprocate.

Provided is a linear compressor capable of reducing noise and manufacturing cost. The linear compressor includes a piston reciprocating within a cylinder, a motor providing a driving force for movement of the piston, a sensing unit sensing a motor voltage and a motor current related to the motor, a discharge part installed at one end of the cylinder and adjusting discharge of a refrigerant compressed within the cylinder, and a controller detecting a load variation of the motor using at least one of the motor voltage and the motor current, calculating a compensation value related to a position of the piston each time a load variation of the motor is detected, and detecting an absolute position of the piston using the calculated compensation value.

A reciprocating fluid pump includes a pump body, a subject fluid chamber, a first plunger located within the subject fluid chamber of the pump body and having a first head portion and a first bellows, the first plunger configured to expand and compress in a reciprocating action to pump the subject fluid through the subject fluid chamber within the pump body, wherein the first head portion and the first bellows have a first cross-sectional dimension, and a second plunger located within the subject fluid chamber of the pump body and having a second head portion and a second bellows, the second plunger configured to expand and compress in a reciprocating action to pump the subject fluid through the subject fluid chamber within the pump body, wherein the second head portion and the second bellows have a second cross-sectional dimension that is smaller than the first cross-sectional dimension.