A sensor apparatus is provided for transmitting data of a polished rod in a rod pumping system, the rod pumping system including a rod rotator that rotates the polished rod. The sensor apparatus includes an outer shell configured to receive the polished rod, a signal processor within the outer shell, a position sensor within the outer shell and configured to sense and output to the signal processor a position signal, and a magnetic pickup sensor configured to sense and output to the signal processor a signal indicating a sensed magnetic field. The signal processor is configured to count a number of strokes of the polished rod based on the position signal, and to determine whether a fault exists based on the number of strokes and the signal indicating the sensed magnetic field.

A system includes a refrigerant compressor and an electronic control device therefor. The compressor includes a drive unit and a compression mechanism drivable thereby having a crankshaft-drivable piston. The control device captures and controls, in an open- and/or closed-loop manner, the crankshaft rotational speed and at least approximately captures the piston position. The control device determines an energy evaluation variable difference while the drive unit is switched off proportional to the energy required to perform one crankshaft revolution; at a measurement rotational speed, determines an energy evaluation variable proportional to the rotational energy at the measurement rotational speed; determines the number of crankshaft revolutions remaining, while the drive unit is switched off, until a standstill of the compression mechanism; and checks whether the remaining crankshaft revolutions upon switch-off of the drive unit at a reference piston position enable stopping of the compression mechanism in the suction phase thereof.

Techniques and apparatus are provided for improved diagnostics of downhole dynamometer data for control and troubleshooting of reciprocating rod lift systems. A method for pump fillage determination for a reciprocating rod lift system is provided. The method generally includes measuring downhole data during a pump cycle, wherein the downhole data comprises a first plurality of data points associated with an upstroke of the pump cycle and a second plurality of data points associated with a downstroke of the pump cycle, each data point comprising a rod position value and an associated rod load value; converting the data points to non-dimensional data points, calculating non-dimensional slope values between non-dimensional data points; and determining pump fillage based, at least part, on the calculated non-dimensional slope values.

A liquid delivery system is presented. The liquid delivery system comprises a source of fluid coupled to an outlet. The liquid delivery system also includes a hydraulic cylinder coupled to the source of fluid. The hydraulic cylinder has a piston movable between a first limit position and a second limit position during an operational cycle. The hydraulic cylinder is configured to pressurize fluid received from the source of fluid, and deliver the pressurized fluid to the outlet. The liquid delivery system also comprises a rod connected to the piston and extending out of the cylinder. The liquid delivery system also comprises a sensor configured to sense a position of the rod to provide a signal indication of the piston with respect to the first position or the second position. An indication of the sensed position is provided to a controller, and the controller is configured to send a control signal to initiate a normal operation loop based on the sensed position.

Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.

A piston pump for feeding a liquid in a vehicle having at least one piston, which is configured to cyclically slide inside a housing between a top dead centre and a bottom dead centre. The liquid is usually fed along a main feeding direction from a suction duct to a delivery duct. The piston pump has two solenoid valves, which are each arranged in the suction duct and in the delivery duct, respectively, and are designed to be operated by an electronic control unit so as to reverse the liquid feeding direction from the main feeding direction to a secondary feeding direction opposite the main liquid feeding direction and/or so as to adjust the cylinder capacity of the piston pump. The piston is operated by an electromechanical actuator, in particular comprising an electromagnet.

A modular multi-channel syringe pump assembly includes a chassis in which are mounted two or more parallel syringe banks. Each syringe bank includes a syringe for retaining a fluid in a chamber with a syringe plunger for drawing fluid into or forcing fluid out of the chamber. A syringe drive actuator includes a syringe drive motor and a mechanical linkage for activating the syringe. At least one position sensor detects syringe position and generates a position signal corresponding to the syringe position. A controller receives the position signal for each syringe bank and generates control signals for operation of the two or more syringe banks.

A diaphragm pump includes a reciprocable diaphragm, an actuator including a motor, and a control device. The control device resets an origin of the diaphragm in a reciprocating direction, when detecting a step-out of the motor. After resetting the origin, the control device activates the actuator to move the diaphragm to the origin.

A diaphragm pump having a conveying chamber and a working chamber, wherein the conveying chamber comprises a pressure connection and a suction connection, and the working chamber can be or is filled with a hydraulic fluid and is operatively connected to a pressure generator in order to apply an oscillating pressure to the hydraulic fluid, further comprising a diaphragm which has at least one diaphragm layer and a diaphragm core and which separates the conveying chamber and the working chamber from one another, and which can be moved from a pressure stroke position into a suction stroke position and back again, the volume of the conveying chamber in the pressure stroke position of the diaphragm being smaller than in the suction stroke position. The diaphragm is or can be brought into operative connection with a diaphragm return device comprising a traction rod, which applies or can apply a force to the diaphragm in the direction of the suction stroke position and further comprising a storage chamber for accommodating the hydraulic fluid, the working chamber and the storage chamber being connected to one another via a channel closed by a closure element.

Presented herein are systems and methods for attenuating flow ripple generated by a hydraulic pump. In certain aspects, a method and system for operating a hydraulic positive displacement pump according to a stabilized command profile are disclosed, such that flow ripple generated by operation of the pump according to the stabilized command profile is attenuated as compared to operation of the pump according to a corresponding nominal command profile. In other aspects, a pressure-balanced active buffer is disclosed that allow for at least partially cancelling flow ripple in a hydraulic circuit comprising a pump. In another aspect, a method for generating ripple maps for a pump is disclosed. Such ripple maps may be used, for example, to determine the stabilized command profile used to operate the pump, or may be used by the pressure-balanced active buffer to counteract ripple in the hydraulic circuit.