Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

Methods, systems, and techniques for harnessing wind energy use a tethered airfoil and a digital hydraulic pump and motor, which may optionally be a combined pump/motor. During a traction phase, a wind powered airfoil is allowed to extend a tether and a portion of the wind energy harnessed through extension of the tether is stored prior to distributing the wind energy to an electrical service. During a retraction phase, the wind energy that is stored during the traction phase is used to retract the tether. The digital hydraulic pump and motor are mechanically coupled to the tether.

Aspects of the disclosure relate to pumping systems, apparatus, end related methods for longer strong lengths and reduced footprints. In one aspect, pumping systems facilitate increased horsepower generated at lower cycle rates and a lesser number of pumps. In one implementation, a pump system comprises a hydraulic power end coupled to and located in between a first fluid end and a second fluid end. The hydraulic power end comprises a hydraulic cylinder assembly having a piston, a first rod coupled to the piston and to the first fluid end, and a second rod coupled to the piston and to the second fluid end located on the opposite side.

Aspects of the disclosure relate to pumping systems, apparatus, end related methods for longer strong lengths and reduced footprints. In one aspect, pumping systems facilitate increased horsepower generated at lower cycle rates and a lesser number of pumps. In one implementation, a pump system comprises a hydraulic power end coupled to and located in between a first fluid end and a second fluid end. The hydraulic power end comprises a hydraulic cylinder assembly having a piston, a first rod coupled to the piston and to the first fluid end, and a second rod coupled to the piston and to the second fluid end located on the opposite side.

A closed-loop hydraulic circuit includes a piston chamber housing a piston rod and a ram piston coupled to an end of the piston rod, and a pump in fluid communication with the piston chamber at first and second hydraulic ports. Pumping a hydraulic fluid to the first hydraulic port causes a forward stroke of the ram piston and the piston rod, and pumping the hydraulic fluid to the second hydraulic port causes a return stroke of the ram piston and the piston rod within the piston chamber. An accumulator is in fluid communication with the pump and the piston chamber, and a 3-2 valve is actuatable between a first position, where pressurized hydraulic fluid is conveyed from the accumulator to the pump during the forward stroke, and a second position, where excess hydraulic fluid is conveyed from the first hydraulic port to the accumulator during the return stroke.

A closed-loop hydraulic circuit includes a piston chamber housing a piston rod and a ram piston coupled to an end of the piston rod, and a pump in fluid communication with the piston chamber at first and second hydraulic ports. Pumping a hydraulic fluid to the first hydraulic port causes a forward stroke of the ram piston and the piston rod, and pumping the hydraulic fluid to the second hydraulic port causes a return stroke of the ram piston and the piston rod within the piston chamber. An accumulator is in fluid communication with the pump and the piston chamber, and a 3-2 valve is actuatable between a first position, where pressurized hydraulic fluid is conveyed from the accumulator to the pump during the forward stroke, and a second position, where excess hydraulic fluid is conveyed from the first hydraulic port to the accumulator during the return stroke.

High-pressure homogeniser (100) comprising:

a volumetric piston pump (1) comprising a plurality of pumping pistons (10);
a homogenising valve (20) arranged downstream of the volumetric piston pump (1); linear motion transmission means (5) of the electro-hydrostatic type, comprising an electric motor (6) and a pump (7) directly driven by the electric motor (6), the pump (7) being operatively active on the pistons (10);
a control unit (40) configured to control the linear motion transmission means (5) such that a reciprocating motion is imposed to each piston (10) according to a law of motion which is pre-established and independent from the laws of motion of the other pistons (10).

An apparatus for conveying thick matter has a drive cylinder for receiving hydraulic fluid, a drive piston, which is arranged in the drive cylinder, a conveying cylinder for receiving thick matter, a conveying piston, which is arranged in the conveying cylinder, and a piston rod, which is fastened to the drive piston for coupling motion together with the conveying piston. The drive cylinder has a rod-side opening for applying pressure to a rod side of the drive piston by way of hydraulic fluid and a crown-side opening for applying pressure to a crown side of the drive piston facing away from the rod side by the hydraulic fluid. A drive pump is designed to generate a drive volume flow having a drive pressure of hydraulic fluid for moving the drive piston. A pump connection is designed for variable connection of the drive pump to the rod-side opening or the crown-side opening for the flow of hydraulic fluid. A sensor is designed for automatic detection of whether the pump connection is connected to the rod-side opening or the crown-side opening. A control unit controls the apparatus in a rod-side operating mode, when the rod-side pump connection is detected, and in a crown-side operating mode, when the crown-side pump connection is detected.

An apparatus for conveying thick matter has a drive cylinder for receiving hydraulic fluid, a drive piston, which is arranged in the drive cylinder, a conveying cylinder for receiving thick matter, a conveying piston, which is arranged in the conveying cylinder, and a piston rod, which is fastened to the drive piston for coupling motion together with the conveying piston. The drive cylinder has a rod-side opening for applying pressure to a rod side of the drive piston by way of hydraulic fluid and a crown-side opening for applying pressure to a crown side of the drive piston facing away from the rod side by the hydraulic fluid. A drive pump is designed to generate a drive volume flow having a drive pressure of hydraulic fluid for moving the drive piston. A pump connection is designed for variable connection of the drive pump to the rod-side opening or the crown-side opening for the flow of hydraulic fluid. A sensor is designed for automatic detection of whether the pump connection is connected to the rod-side opening or the crown-side opening. A control unit controls the apparatus in a rod-side operating mode, when the rod-side pump connection is detected, and in a crown-side operating mode, when the crown-side pump connection is detected.

A metering mechanism including a metering element that is translatably mounted in a jacket, the jacket being mounted in an adjusting sleeve that can cooperate with the jacket by way of a screwing movement, the screwing/unscrewing movement causing a translatory movement of the metering element; at one end, the metering element is provided with a check valve, and at the other end, same accommodates a plunger, the reciprocating translatory movement of which creates suction at the end of the element provided with the valve, followed by expulsion into a volume surrounding the other end of the metering element via a passage formed in at least one first sealing device and in a second sealing device. A proportioning pump including a metering mechanism of the type as well as to a method for using a pump of the type in at least two metering ranges.