Provided is a technology for reducing the capacity of a liquid feeding pump and enabling liquid feeding with little pulsation. A liquid feeding pump according to the present disclosure is provided with: a first plunger pump having a first plunger; a second plunger pump having a second plunger and connected in series with the first plunger pump; a pressure sensor disposed downstream of the second plunger pump; and a control unit that accepts the input of a liquid discharge pressure measured by the pressure sensor and that controls the driving of the first plunger and the driving of the second plunger. The control unit calculates the rate of change in the pressure of the liquid on the basis of the past compression distances of the plunger for when the liquid was compressed by the first plunger pump and the pressure at the completion of compression, predicts the compression distance of the first plunger on the basis of the rate of change in pressure and the present discharge pressure, and determines the timing at which the compression performed by the first plunger will be completed on the basis of the predicted compression distance.

A diaphragm pump system that includes a pair of working fluid diaphragm pump assemblies that are each fluidly connected to a working fluid flow. Each working fluid diaphragm pump assembly is operationally associated with a discrete drive arrangement that is fluidly isolated from the working fluid flow that is moved during operation of the pump system. A control arrangement is connected to the discrete drive arrangements and configured to control the cyclic operation of the pair of working fluid diaphragm pump assemblies to mitigate pulsatile effects in the combined working fluid flow when the discharges of the working fluid flows associated with operation of the pair of working fluid diaphragm pump assemblies is combined.

A diaphragm pump system that includes a pair of working fluid diaphragm pump assemblies that are each fluidly connected to working fluid flows. Each working fluid diaphragm pump assembly is operationally associated with a drive arrangement that is fluidly isolated from the working fluid flow that is moved during operation of the pump system. A manifold assembly connects the discrete drive arrangements and is constructed to control the cyclic operation of the pair of working fluid diaphragm pump assemblies to mitigate pulsatile effects in the combined working fluid flow when the discharges of the working fluid flows associated with operation of the pair of working fluid diaphragm pump assemblies is combined and independent of the contributions of the discrete diaphragm pumps to the resultant combined output fluid flow.

Disclosed is a conveying device for fluids with an inlet and an outlet and a conveying part which is connected therebetween and can be actuated by a drive part, wherein the conveying part has a fluid-tight media-separating device with a variable chamber volume, which becomes connected in a fluid-conducting manner via its receiving chamber to the inlet or the outlet, and which, by means of the drive part, receives fluid via the inlet as part of an intake stroke, increasing the chamber volume, and discharges the received fluid via the outlet as part of a discharge stroke, reducing the size of said chamber volume.

A hydraulic circuit arrangement includes a plurality of electronically-commutated pumps providing flow to a common hydraulic line, the plurality of electronically-commutated pumps including one or more quantized electronically-commutated pumps and one or more unquantized electronically-commutated pumps. A controller includes a pressure controller and a flow divider. The pressure controller is configured to receive a pressure signal corresponding to the pressure within the common hydraulic line, to compare the pressure signal to a demanded pressure, and to determine a target flow value required to produce the demanded pressure. The flow divider is configured to receive the target flow value and allocate the target flow value into a quantized target flow value for allocation among the one or more quantized electronically-commutated pumps and an unquantized target flow value for allocation among the one or more unquantized electronically-commutated pumps.

Disclosed is a constant flow pump, including a constant flow pump case. A motor support base is fixedly mounted at a top of the constant flow pump case, A drive motor is fixedly mounted at a top of the motor support base. An output end of the drive motor penetrates through the motor support base. A coupling is arranged in the motor support base. A linkage rod is driven by an adjusting hand wheel to enable a connecting plate to move internally. A limiting bump is separated from a slot. A butting seat can be extracted. A rotating shaft and an eccentric cam are detached rapidly. During mounting, the butting seat with a new component is inserted, the limiting bump is in contact with the slot, the adjusting hand wheel is loosened, and a limiting spring enables the bump to be clamped into the slot to accomplish clamping.

Disclosed is a constant flow pump, including a constant flow pump case. A motor support base is fixedly mounted at a top of the constant flow pump case, A drive motor is fixedly mounted at a top of the motor support base. An output end of the drive motor penetrates through the motor support base. A coupling is arranged in the motor support base. A linkage rod is driven by an adjusting hand wheel to enable a connecting plate to move internally. A limiting bump is separated from a slot. A butting seat can be extracted. A rotating shaft and an eccentric cam are detached rapidly. During mounting, the butting seat with a new component is inserted, the limiting bump is in contact with the slot, the adjusting hand wheel is loosened, and a limiting spring enables the bump to be clamped into the slot to accomplish clamping.