An anti-ripple injection method for injecting an anti-ripple signal into a control system of a pump is disclosed. The control system controls an electric motor via an electric motor drive, and the electric motor drives the pump. The anti-ripple signal causes pressure ripples in the pump output to be at least partially cancelled. The anti-ripple injection method comprises: injecting an anti-ripple signal of any waveform into the control system, the anti-ripple signal being represented by the following equation: f(θ)=Σ.sub.mA.sub.mcos(mθ+θ.sub.m), wherein θ is the rotation angle of the motor shaft, m is the order of a signal harmonic in the anti-ripple signal, A.sub.m and θm are parameters with respect to the m.sup.th signal harmonic. A control system of a pump including the anti-ripple injection apparatus, and a pump system including the control system are also disclosed.

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.

Disclosed is a status monitoring and fault diagnosis system for a plunger pump, including a monitoring and fault diagnosis device. The monitoring and fault diagnosis device monitors and diagnoses a hydraulic end assembly of a plunger pump. The monitoring and fault diagnosis device further monitors and diagnoses a power end assembly and/or a reduction gearbox assembly. Beneficial effects: The diagnosis system monitors and diagnoses not only a hydraulic end assembly, but also a power end assembly and/or a reduction gearbox assembly, that is, an equipment fault can be accurately predetermined in time for an entire plunger pump, so that high-pressure, large-displacement, and continuous operation requirements on fracturing sites at present are better satisfied, and on-demand maintenance is adopted instead of regular examination and maintenance, thereby saving labor, time, and materials to achieve economic efficiency.

A position detection device determines the position of the diaphragm or the drive piston of an electric-motor-driven diaphragm pump, in particular, by detecting the upper and lower reversal point (Po, Pu) in the movement curve of the diaphragm of the diaphragm pump. A diaphragm is actuated by a drive connecting rod to close a conveying chamber with valves provided on an inlet and outlet side. The volume can be changed between a minimum and maximum volume. A rotational movement of an electric motor, with a rotor, is converted into the actuation movement of the drive connecting rod via the effect of the eccentrics. The position detection device detects the load curve of the diaphragm pump during the movement of the diaphragm. An evaluation device determines at least the position of the upper and lower reversal point of the diaphragm from the load curve.

The disclosure relates to a position detection device for determining the position of the diaphragm or the drive piston of an electric-motor-driven diaphragm pump, in particular detecting the upper and lower reversal point (Po, Pu) in the movement curve of the diaphragm of a diaphragm pump operated in an electric-motor-driven manner via eccentric means, wherein a diaphragm actuated by a drive connecting rod closes a conveying chamber with valve means provided on an inlet and outlet side such that the volume can be changed between a minimum and maximum volume, whereby a reciprocating movement of an electric motor having a rotor attached to a shaft is converted into an actuation movement of the drive connecting rod via the effect of the eccentric means, wherein the position detection device has detecting means for detecting the average value position of the rotor shaft, as well as an evaluation device in order to determine at least the position of the upper reversal point of the diaphragm from the average value position.

Various embodiments include methods for operating a high-pressure pump comprising: driving a piston arranged in a compression chamber with a motor shaft; during movement of the piston toward the top dead center, closing the inlet valve so the fluid is then delivered by the piston through an outlet valve; applying a coil current to an electromagnet used to close the inlet valve during and/or after overshooting the top dead center; detecting a start time at which the coil current, on account of starting of an opening movement of the inlet valve, fulfills a predetermined change criterion; labelling a dead center rotation position of the motor shaft at which the piston is at the top dead center based at least in part on the ascertained start time; and adjusting operation of the pump based on the identified dead center rotation position.

A system for monitoring a hydraulic fracturing pump includes a first sensor configured to measure a discharge fluid pressure of the pump, a second sensor configured to sense a displacement of a crankshaft of the pump, a processor communicatively coupled to the first and second sensors and configured to analyze the sensor data and determine a cycle count, duty cycle, and operating hour value for the positive displacement pump, and a display coupled to the processor configured to display the cycle count, duty cycle, and operating hour value.

An ocular drainage system is provided for treating diseases that produce elevated intraocular pressures, such as glaucoma, wherein the system includes an implantable device and an external control unit, the implantable device includes a non-invasively adjustable valve featuring at least one deformable tube and a disk rotatably mounted within a housing, such that rotation of the disk using the external control unit causes the disk to apply a selected amount of compression to the deformable tube, thereby adjusting the fluidic resistance of the deformable tube and regulating the intraocular pressure.

A peristaltic pump precise dosing control system includes a driver, a pump head, pipeline switching means, a metering pipeline, and a discharge pipeline. An elastic tubing is provided in the pump head, and the outlet end of the elastic tubing is connected to the pipeline switching means. The driver drives the pump head to rotate to pump the liquid in the elastic tubing to the outlet end of the elastic tubing. The driver is electrically connected to the pipeline switching means so as to be capable of controlling the pipeline switching means to switch to the output pipeline with which the outlet end of the elastic tubing is connected. The pipeline switching means is driven to switch the outlet end of the elastic tubing from a state of connection with the discharge pipeline to a state of connection with the metering pipeline.

The present disclosure provides a device for monitoring oil pressure in an oil cylinder of a diaphragm compressor, including a piston rod and a strain gauge circuit. The strain gauge circuit includes a strain gauge component and a bridge circuit connected, and the strain gauge component is arranged on the surface of the piston rod. A strain gauge component is noninvasively arranged on the piston rod of the diaphragm compressor to measure the load of the piston rod, such that the oil pressure can be measured indirectly, and thus the oil pressure of the diaphragm compressor can be measured nondestructively. Nondestructive and noninvasive monitoring of the diaphragm compressor is safe and reliable, and can achieve accurate monitoring of the oil pressure especially in high-pressure working conditions.