A diaphragm pump includes a pumping chamber for pumped fluid and a hydraulic chamber. A diaphragm has a pumping chamber side and a hydraulic chamber side. The pumping chamber side of the diaphragm is proximate the pumping chamber and acts on the pumped fluid. The hydraulic chamber side of the diaphragm is proximate the hydraulic chamber. A plunger is in fluid communication with the hydraulic chamber and acts on the hydraulic fluid, which acts on the diaphragm. A plunger driver imparts reciprocal motion to the plunger. The pump includes a sensor assembly sensing position and direction of the plunger and sensing position of the diaphragm. By sensing the position of the diaphragm, hydraulic fluid flow is controlled by a control single valve.

A monitor and control system for a hydraulic fracturing pump is described herein to reduce or eliminate harmful oscillations in fluid discharge pressure caused by the pump load dynamics. The monitor and control system receives various sensor data from the operation of the pump, including the pump crank position, and executes a pump control equation or model based on the pump sensor data, pump load data and/or pump speed data. Pump control equations or models are specific to the design and dynamic operation of the pump, incorporating the number of plungers, pump dynamics, motor lag and motor dynamics, etc. Using the pump control equations or models, the monitor and control system determines control commands for the pump motor to reduce or eliminate the oscillatory discharge pressure at the pump.

A motor/pump assembly for a brake system includes at least one fluid pump arranged in a pump housing, an electric motor having a motor shaft configured to drive the fluid pump, a control unit arranged on the pump housing and configured to set a current rotational speed and/or a current torque of the motor, and a sensor arrangement having a measured value transmitter arranged within the pump housing and a magnetic measured value pickup stationarily arranged in the control unit. The control unit is further configured to detect contactlessly a current rotational angle of the shaft via the sensor arrangement, and to evaluate the angle to control the motor. The transmitter, in accordance with a rotary motion of the shaft, is configured to influence at least one magnetic variable of a magnetic field detected by the pickup.

A monitoring system may include a position sensor, strain gauges, and a computing device for monitoring valves in a pressure pump having multiple chambers to determine critical valve limits for the valves using strain measurements for each charmber. The strain gauges may determine strain in each chamber of the pressure pump. The position sensor may determine the position of a crankshaft mechanically coupled to a plunger in each chamber. The computing device may receive signals generated by the strain gauges and the position sensor related to the strain in each chamber and the position of the crankshaft, respectively, and may process the signals to determine delays in the actuation of the valves for determining critical valve limits.

A monitoring system may include at least a strain gauge and a computing device for determining a bulk modulus of a fluid system of a pressure pump using strain measurements. The strain gauge may determine strain in a chamber of the pressure pump. The computing device may receive a strain signal generated by the strain gauge and may correlate the strain signal to pressure to determine a change in pressure during a period in which fluid is isolated in the chamber. The computing device may use the change in pressure during this period to determine a bulk modulus of the fluid system.

A monitoring system may include a position sensor, a strain gauge, and a computing device for determining the condition of a valve in a chamber of a pump using strain measurements. The strain gauge may determine strain in the chamber. The position sensor may determine the position of a crankshaft coupled to a plunger in the chamber. The computing device may receive signals generated by the strain gauge and the position sensor related to the strain in the chamber and the position of the crankshaft, respectively, and may process the signals to determine delays in the actuation of the valves.

A control device for a fuel injection system includes a CPU which generates a drive signal for instructing execution of compression by a fuel pump; a fuel pump drive circuit which controls application of electric power to a solenoid of the fuel pump based on the drive signal; a boost circuit provided with a capacitor for storing electric power to be used for driving an injector; a charging circuit which leads a current generated when the application of electric power to the solenoid is stopped to the capacitor; and an excess electric power consumption circuit which consumes excess electric power of the capacitor. While fuel injection from the injector is stopped, the CPU counts the number of times the fuel pump is driven and turns off the drive signal so as to stop driving the fuel pump as soon as the drive count has exceeded a predetermined count value.

A liquid soap dispenser, which controls positive and reverse rotations of a motor and a liquid discharge amount through angle counting, includes a front cover, a back cover, a liquid soap bottle, a pump component, a main engine and a key. An angle counter is arranged in the main engine. The liquid soap dispenser is connected with the motor. The angle counter is driven to rotate through the motor, so as to measure a rotation angle of the motor. The motor is connected with a gearbox, and the gearbox is connected with an output gear. The output gear is fastened at a lower part of the pump component, and the pump component is driven to move through the output gear. The liquid soap dispenser realizes a stepless adjustment of the liquid discharge amount through controlling the motor to reversely rotate.

Systems, methods, and non-transitory media for monitoring a reciprocating compressor determining a valve opening of a valve disposed in the reciprocating compressor using a sensor and determining a first location of a piston of the reciprocating compressor at the valve opening. The monitoring also includes determining a valve closing of the valve using the sensor and determining a second location of the piston at the valve closing. Furthermore, the monitoring includes estimating a volumetric efficiency based at least in part on the first and second location.

Various embodiments of the present disclosure are directed to reciprocating compressors. In one example embodiment, a reciprocating compressor is disclosed including a cylinder, a piston, at least one suction valve, at least one pressure valve, at least one connection chamber, a sequence valve, a sequence valve control unit, and an unloader. The piston moves back and forth in the cylinder in order to form a compression chamber in the cylinder. The at least one suction valve and the at least one pressure valve are provided on the compression chamber. The at least one connection chamber having a connection chamber volume, which is connected to the compression chamber via at least one overflow opening. The sequence valve opens and closes the at least one overflow opening, and the sequence valve control unit controls the sequence valve. The unloader is actuated by an electrically controllable actuator.