A variable displacement hydraulic device comprising: a housing having an inlet for receiving hydraulic fluid and an outlet for outputting the hydraulic fluid, the housing having a reciprocation axis; a first cylinder positioned in the housing along the reciprocation axis, the first cylinder having a first input for receiving the hydraulic fluid on a first intake stroke and a first output for ejecting the hydraulic fluid on a first exhaust stroke; a first piston positioned for a first reciprocal motion within the first cylinder, the first piston having a first main end exposed to the hydraulic fluid and a second main end coupled to an actuator, the actuator for driving the second main end when coupled to the actuator for causing the first reciprocal motion to induce a first portion of said outputting of the hydraulic fluid; a second cylinder positioned in the first piston along the reciprocation axis, the second cylinder having a second input for receiving the hydraulic fluid on a second intake stroke and a second output for ejecting the hydraulic fluid on a second exhaust stroke; a second piston positioned for a second reciprocal motion within the second cylinder, the second piston having a first secondary end exposed to the hydraulic fluid and a second secondary end coupled to the actuator, the actuator for driving the second secondary end when coupled to the actuator for causing the second reciprocal motion to induce a second portion of said outputting of the hydraulic fluid; and a locking mechanism for inhibiting the first reciprocal motion of the first piston; wherein when engaged the locking mechanism inhibits the first portion of said outputting of the hydraulic fluid by decoupling the first piston from the actuator while continued operation of the actuator provides the second portion of said outputting of the hydraulic fluid by the second piston.

The invention relates to a fluid compression apparatus having a plurality of compression stages, comprising a first compression chamber, a second compression chamber, an intake system communicating with the first compression chamber which is configured to allow fluid to be compressed into said first compression chamber, a transfer system configured to allow in an open position the transfer of fluid from the first compression chamber to the second compression chamber, a mobile piston for ensuring the compression of the fluid in the first and second compression chambers. The apparatus further comprises a discharge port which communicates with the second compression chamber and is configured to allow the exit of compressed fluid, the piston being translationally mobile in a longitudinal direction, wherein the first compression chamber is defined by a fixed lower cavity, a lower end of the piston and a first sealing system formed between the piston and a wall of the cavity, wherein the second compression chamber is defined by a fixed upper cavity, an upper end of the piston and a second sealing system formed between the piston and a wall of the upper cavity. The invention is characterized in that, in the operating configuration of the apparatus, the longitudinal direction of translation of the mobile piston is vertical, the intake system being located at a lower end of the apparatus and the discharge port being located in an upper part of the apparatus above the transfer system.

The invention relates to a fluid compression apparatus having a plurality of compression stages, comprising a first compression chamber, a second compression chamber, an intake system communicating with the first compression chamber which is configured to allow fluid to be compressed into said first compression chamber, a transfer system configured to allow in an open position the transfer of fluid from the first compression chamber to the second compression chamber, a mobile piston for ensuring the compression of the fluid in the first and second compression chambers. The apparatus further comprises a discharge port which communicates with the second compression chamber and is configured to allow the exit of compressed fluid, the piston being translationally mobile in a longitudinal direction, wherein the first compression chamber is defined by a fixed lower cavity, a lower end of the piston and a first sealing system formed between the piston and a wall of the cavity, wherein the second compression chamber is defined by a fixed upper cavity, an upper end of the piston and a second sealing system formed between the piston and a wall of the upper cavity. The invention is characterized in that, in the operating configuration of the apparatus, the longitudinal direction of translation of the mobile piston is vertical, the intake system being located at a lower end of the apparatus and the discharge port being located in an upper part of the apparatus above the transfer system.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps:

a. pumping a multi-phase mixture into a discharge-side separation chamber (45),

b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45),

c. separating the liquid phase from the solid phase in the separation chamber (45), and

d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps: a. pumping a multi-phase mixture into a discharge-side separation chamber (45), b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45), c. separating the liquid phase from the solid phase in the separation chamber (45), and d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

The invention concerns a method and an apparatus for operating a multi-phase pump which has a suction-side inlet (10) and a discharge-side outlet (20) and which pumps a multi-phase mixture charged with solids, comprising the following steps: a. pumping a multi-phase mixture into a discharge-side separation chamber (45), b. separating a gaseous phase from a liquid phase and a solid phase in the separation chamber (45), c. separating the liquid phase from the solid phase in the separation chamber (45), and d. supplying a portion of the liquid phase freed from the solid phase to the suction side.

A hydraulic piston pump motor in which water is used as a working fluid includes an axial directional passage opened on an end surface of one end of a shaft that couples to a cylinder block and drilled open along a shaft center of the shaft; a first radial directional passage drilled open along a radial direction of the shaft from the axial directional passage and configured to guide working fluid into a casing; a second radial directional passage drilled open from the axial directional passage along the radial direction of the shaft at a position closer to the one end of the shaft than the first radial directional passage; and an introduction passage communicating a passage, through which the higher pressure working fluid flows, among the supply passage and the discharge passage with the axial directional passage.

A hydraulic piston pump motor in which water is used as a working fluid includes an axial directional passage opened on an end surface of one end of a shaft that couples to a cylinder block and drilled open along a shaft center of the shaft; a first radial directional passage drilled open along a radial direction of the shaft from the axial directional passage and configured to guide working fluid into a casing; a second radial directional passage drilled open from the axial directional passage along the radial direction of the shaft at a position closer to the one end of the shaft than the first radial directional passage; and an introduction passage communicating a passage, through which the higher pressure working fluid flows, among the supply passage and the discharge passage with the axial directional passage.

A hydraulic rotary machine includes a plurality of pistons, a cylinder block accommodating the pistons, a shaft penetrating through the cylinder block, a swash plate making the pistons reciprocate to expand and contract a capacity chamber of the cylinder, a casing accommodating the cylinder block, a front cover closing an opened end of the casing, an extending portion formed in the front cover and extending along the shaft towards the cylinder block, and a first slide bearing provided between the extending portion and the cylinder block. The first slide bearing is fixed to the extending portion or the cylinder block by a pin member.

A hydraulic rotary machine includes a plurality of pistons, a cylinder block accommodating the pistons, a shaft penetrating through the cylinder block, a swash plate making the pistons reciprocate to expand and contract a capacity chamber of the cylinder, a casing accommodating the cylinder block, a front cover closing an opened end of the casing, an extending portion formed in the front cover and extending along the shaft towards the cylinder block, and a first slide bearing provided between the extending portion and the cylinder block. The first slide bearing is fixed to the extending portion or the cylinder block by a pin member.