A hydraulic system that has a hydraulic pump connected to and in communication with a hydraulic motor, at least one hydraulic cylinder, or both by a first conduit and a second conduit (i.e., a high side and a low side). The hydraulic system has a bypass valve connected to and in communication with the first conduit and the second conduit. The bypass valve has a preset pressure that is above a minimum low side pressure. When a shock load occurs in the hydraulic system and a related drop in pressure on the low side occurs, the bypass valve opens when the preset pressure is passed thereby preventing the pressure from dropping to the minimum low side pressure. The hydraulic system thereby avoids a low loop event that could cause damage to the hydraulic system without the presence of larger charge pumps or accumulators.

A piston pump and a method for determining a volume V.sub.eff of a liquid medium delivered to a consumer by a double acting, pneumatically driven piston pump, wherein the piston pump is subject to leakage when a constant pressure is acting on a drive of the piston pump and at least one double stroke of a piston pump from one dead center position thereof to the other dead center position thereof and back to the first dead center position is carried out includes: a. without the piston pump being able to deliver the medium to the consumer, a leakage time t.sub.L auf for one stroke of the piston pump from the bottom dead center position thereof to the top dead center position thereof is measured, b. without the piston pump being able to deliver the medium to the consumer, a leakage time t.sub.L ab for one stroke of the piston pump from the top dead center position thereof to the bottom dead center position thereof is measured, c. a quotient of a volume of the medium V.sub.auf theoretically delivered by the piston pump without leakage and of the leakage time t.sub.L auf is determined for the stroke of the piston pump from the bottom dead center position to the top dead center position, d. a quotient of a volume V.sub.ab theoretically delivered by the piston pump without leakage and of the leakage time t.sub.L ab is determined for the stroke of the piston pump from the top dead center position to the bottom dead center position, e. the time t.sub.auf for the stroke of the piston pump from the bottom dead center position to the top dead center position and the time t.sub.ab for the stroke of the piston pump from the top dead center position to the bottom dead center position is measured as the medium is delivered to the consumer, f. the effectively delivered volume V.sub.eff is multiplied by the number of double strokes in accordance with

[00001]$V_{\mathrm{eff}}=\left(V_{\mathrm{auf}}-\frac{V_{\mathrm{auf}}}{t_{L.Math..Math.\mathrm{auf}}}{t}_{\mathrm{auf}}\right)+(V_{\mathrm{ab}}-\frac{V_{\mathrm{ab}}}{t_{L.Math..Math.\mathrm{ab}}}{t}_{}$

A hydraulic pump includes a work port, a high-flow piston, multiple high-pressure pistons, and an unloading valve. The work port couples to a fluid supply line of a hydraulic tool. The high-flow piston supplies fluid along a first flow path to the work port. The high-pressure pistons supply fluid along a second flow path to the work port. The unloading valve is fluidly coupled to the first flow path and the second flow path, and actuatable between an open state and a closed state. The unloading valve is configured to (i) permit fluid to flow from the high-flow piston to the work port in the open state, (ii) inhibit fluid from flowing from the high-flow piston to the work port in the closed state, and (iii) actuate from the open state to the closed state when a pressure of the fluid in the second flow path exceeds a threshold pressure.

A hydraulic pump includes a work port, a high-flow piston, multiple high-pressure pistons, and an unloading valve. The work port couples to a fluid supply line of a hydraulic tool. The high-flow piston supplies fluid along a first flow path to the work port. The high-pressure pistons supply fluid along a second flow path to the work port. The unloading valve is fluidly coupled to the first flow path and the second flow path, and actuatable between an open state and a closed state. The unloading valve is configured to (i) permit fluid to flow from the high-flow piston to the work port in the open state, (ii) inhibit fluid from flowing from the high-flow piston to the work port in the closed state, and (iii) actuate from the open state to the closed state when a pressure of the fluid in the second flow path exceeds a threshold pressure.

An electrofluidic assembly and method for its operation. The functions of a reciprocating pump and of a valve should be combined in one assembly. Here, in particular the pump and the valve should interact so that a small number of line connections are required. A pump assembly and a valve are arranged on an identical central line and use a bearing rod jointly for movable bearing of a first solenoid armature which activates a displacement apparatus of the pump assembly on one hand and a second solenoid armature of the valve which activates a group of closing bodies on the other hand. The electrofluidic assembly can be used for monitoring tank systems.

A fluid compressor system having an electro-magnetic throttle valve (EMTV) that utilizes magnetic forces supplied by an electromagnet to actuate the opening and closing of the valve. The fluid compressor system may include a control system that controls the position of a valve plate of the EMTV, allowing the EMTV to fully or partially actuate to a plurality of intermediate positions depending on a current supplied to the electromagnet by the control system. The control system may control a location of the valve plate with reference to the electromagnet by balancing the forces acting on the valve plate, such as electromagnetic forces supplied by the electromagnet, biasing forces supplied by biasing components, and gravitational forces acting on the valve plate. The EMTV may include a blowdown system configured to release a pressure within the fluid compressor system when the inlet on the EMTV is closed.

Systems and methods for an air compressor control system includes a user interface configured to receive a command from an operator, a sensor configured to measure one or more characteristics of the system, an electric inlet valve integrated within an air compressor and configured to regulate airflow of the air compressor based on a position of the electric inlet valve, and a controller configured to adjust a position of the electric inlet valve via an electrical control signal in response to a command from the user interface or a measurement from the sensor.

The present invention relates to diaphragm pump (1) having a delivery chamber (3) and a working chamber (5), wherein the working chamber can be or is filled with a hydraulic fluid and is operatively connected to a pressure generating device in order to apply an oscillating pressure to the hydraulic fluid, further comprising a diaphragm (11) having at least one diaphragm layer (13) and a diaphragm core (15), which separates the delivery chamber (3) and the working chamber (5) from each other, wherein the diaphragm (11) is or can be operatively connected to a diaphragm return device (17) comprising a pull rod (19), which applies or can apply a return force on the diaphragm (11) in the direction of the suction stroke position, and further comprising a storage chamber (21) for holding the hydraulic fluid, and wherein the working chamber (5) and the storage chamber (21) are connected to each other by means of a return flow channel (25) closed by means of a closure element (23, 23), and wherein the closure element (23, 23) is operatively connected to the diaphragm core (15) and the diaphragm return device (17), so that the return force and a pressure force counteracting the return force as a result of the fluid pressure in the working chamber (5) act on the closure element (23, 23), and wherein, when a predetermined triggering force is exceeded as a sum of the return force and the pressure force on the closure element (23, 23), the return flow channel (25) is opened.

A variable displacement swash plate type compressor includes a first and a second valve body, and a suction and a bleed window. An open degree of the suction window is minimized by the first valve body and an open degree of the bleed window is maximized by the second valve body when a suction pressure is lower than a predetermined suction pressure and a crank chamber pressure is higher than a control pressure. The open degree of the suction window is increased and the open degree of the bleed window is maximized when the suction pressure is higher than the predetermined suction pressure and the crank chamber pressure is higher than the control pressure. The open degree of the suction window and the open degree of the bleed window are decreased when the crank chamber pressure is lower than the control pressure.

A hydraulic pump includes a work port configured to supply fluid to a hydraulic tool. A high-flow piston supplies fluid along a first flow path to the work port and plurality of high-pressure pistons supplies fluid along a second flow path to the work port. An unloading valve is positioned along the first flow path and actuates from an open state to a closed state when a pressure level of the fluid in the second flow path exceeds a first threshold pressure. A controller allows a user to select a mode of operation. The controller sets a second threshold pressure of the hydraulic pump based on the selected mode of operation, and the second threshold pressure corresponds to an end operation of the hydraulic tool.