A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A rotatable piston assembly for a reciprocating piston type hydraulic machine includes a rotatable piston configured for a controlled rotation and configured to reciprocate within a cylinder bore of the reciprocating piston type hydraulic machine.

A hydraulic device having a plurality of cylinders for distributing a flow of hydraulic fluid between a reservoir and a load, the device comprising: a housing having the plurality of cylinders with a plurality of corresponding pistons configured for reciprocation of a constant stroke length; an input port of the housing fluidly connected to each cylinder of the plurality of cylinders, the input port facilitating introduction of the hydraulic fluid into said each cylinder; an output port of the housing connected to said each cylinder, the output port facilitating the ejection of the hydraulic fluid from said each cylinder during the reciprocation, the output port configured for fluidly coupling said each cylinder to the load; and a distributor coupled to a main shaft of the hydraulic device, such that the distributor rotates in conjunction with the main shaft, the distributor having a distributor body including a first port configured for fluid communication with the input port and a second port configured for fluid communication with the output port; wherein the first port and the second port are fluidly coupled to the input port and the output port external to a shaft body of the main shaft.

A hydraulic device having a plurality of cylinders for distributing a flow of hydraulic fluid between a reservoir and a load, the device comprising: a housing having the plurality of cylinders with a plurality of corresponding pistons configured for reciprocation of a constant stroke length; an input port of the housing fluidly connected to each cylinder of the plurality of cylinders, the input port facilitating introduction of the hydraulic fluid into said each cylinder; an output port of the housing connected to said each cylinder, the output port facilitating the ejection of the hydraulic fluid from said each cylinder during the reciprocation, the output port configured for fluidly coupling said each cylinder to the load; and a distributor coupled to a main shaft of the hydraulic device, such that the distributor rotates in conjunction with the main shaft, the distributor having a distributor body including a first port configured for fluid communication with the input port and a second port configured for fluid communication with the output port; wherein the first port and the second port are fluidly coupled to the input port and the output port external to a shaft body of the main shaft.

An automatic double-acting valve includes: a valve body, a central duct, passing through the valve body and is equipped with a first opening made in a first end of the valve body and a second opening made in an opposite second end, a peripheral duct made in the valve body, eccentric to the central duct and equipped with a first opening, in a side surface between the first end and the second end, and a second opening in the second end of the valve body, a first blocking body movable at least between a closed position, in which it obstructs the first opening of the central duct, and an open position, a first elastic element configured to generate a force adapted to keep the first blocking body closed, a second blocking body movable at least between a closed position, in which it obstructs the second opening, and an open position.

An automatic bidirectional valve includes: a valve body, a central conduit that crosses the valve body and is provided with a first opening in a first end of the valve body and a second opening made in an opposite second end thereof, and a peripheral conduit made in the valve body, provided with a first opening, made in a portion of the valve body between the first and second ends, and a second opening made in the second end. A first shutter is movable between a closing position and an opening position, a first elastic element configured to generate a force adapted to maintain the first shutter in the closing position, a second shutter movable between a closing position, and an opening position, a second elastic element configured to generate a force to maintain the second shutter in the closing position, and a retaining body fixed to the valve body.

A control mechanism for a hydrostatic transmission includes a piston rod, a neutral biasing spring, a piston, a cylinder case provided with a first fluid chamber and a second fluid chamber, a solenoid valve capable of selectively supplying pressurized fluid to the first fluid chamber and the second fluid chamber, a pivot shaft configured to swingably support the cylinder case, and a first relief valve configured to flow the hydraulic fluid from the first fluid chamber to the second fluid chamber when a hydraulic pressure in the first fluid chamber exceeds a set pressure, and a second relief valve configured to flow the hydraulic fluid from the second fluid chamber to the first fluid chamber when a hydraulic pressure in the second fluid chamber exceeds a set pressure.

High pressure pumps and associated check valves for use with, e.g., waterjet systems, are disclosed herein. In some embodiments, high pressure pumps configured in accordance with the present disclosure include check valve assemblies that eliminate threaded parts for restricting the motion of check valve components which are subjected to very high pressure variations at relatively high frequencies. Additionally, embodiments of the pumps described herein can include unitary structures that integrate the individual parts associated with multiple cylinders (e.g., cylinders, check valve bodies, etc.) into a single part (e.g., a cylinder manifold, check valve manifold, outlet manifold, etc.) that can substantially reduce the number of different parts required to assemble the pump.

High pressure pumps and associated check valves for use with, e.g., waterjet systems, are disclosed herein. In some embodiments, high pressure pumps configured in accordance with the present disclosure include check valve assemblies that eliminate threaded parts for restricting the motion of check valve components which are subjected to very high pressure variations at relatively high frequencies. Additionally, embodiments of the pumps described herein can include unitary structures that integrate the individual parts associated with multiple cylinders (e.g., cylinders, check valve bodies, etc.) into a single part (e.g., a cylinder manifold, check valve manifold, outlet manifold, etc.) that can substantially reduce the number of different parts required to assemble the pump.

A pump module and a device for producing a fluid jet with a pump module are disclosed. In an embodiment the pump module may include a pump housing in which at least one pump piston is mounted in a reciprocatingly movable manner and is provided with at least one sealing element which during a pumping operation interacts with a cylinder. For creating such a pump module producible in a simple manner and nevertheless exhibiting the functionality necessary for the pumping operation, embodiments disclose a valve block, which receives at least one valve associated with the cylinder, wherein the cylinder is sealed against the valve block. Furthermore, a cover element may abut against the valve block on a side opposite to the cylinder and between itself and the valve block forms an inlet passage leading to the cylinder and/or an outlet passage communicating with the cylinder.