The devices comprises a distributor (16) that presents distribution ducts opening out into a radial distribution face (16A), and a distributor-counterpart engaged in each other in such a manner that two main enclosures (18, 20) are provided between their opposite axially-extending faces. The device comprises a cylinder-capacity selector comprising two slides (24, 26) arranged after the other in a bore (22) of the element engaged in the other, to which are connected the main enclosures (18, 20) and at least some of the distribution ducts (30, 31). The slides are able to adopt at least three distinct configurations establishing different connections between the main ducts (18, 20) and the distribution ducts via the main enclosures, in order to be able to obtain at least three distinct operating cylinder capacities.

A rotary hydraulic machine with radial pistons comprising: a rotating shaft (2); a cylinder-housing body (3), having a plurality of housing seatings (4) arranged radially at equal distances from the rotation axis (R) of the rotating shaft (2); a cylinder (5) housed in each of said plurality of housing seatings (4) and rotating relative to the same around an axis (C) concentric with said rotation axis (R) of the rotating shaft (2); a piston (6) slidable in each cylinder (5) and coupled to a crank (7) of the rotating shaft (2); a supply conduit (12), for each cylinder (5), provided with a seal (120) arranged to enable a sealed connection between the supply conduit (12) and the respective cylinder (5).

Each seal (120) comprises: a first ring (121), arranged at an end of the supply conduit (12) and placed in contact with the cylinder (5); a second ring (122), concentric to the first ring (121) and interposed between the supply conduit (12) and the first ring (121), wherein the second ring (122) is coupled by interference with the first ring (121) and is inserted by interference into the supply conduit (12) in such a way as to prevent a rotation of the first ring (121) with respect to the supply conduit (12) around a common axis (X).

A rotary hydraulic machine with radial pistons comprising: a rotating shaft (2); a cylinder-housing body (3), having a plurality of housing seatings (4) arranged radially at equal distances from the rotation axis (R) of the rotating shaft (2); a cylinder (5) housed in each of said plurality of housing seatings (4) and rotating relative to the same around an axis (C) concentric with said rotation axis (R) of the rotating shaft (2); a piston (6) slidable in each cylinder (5) and coupled to a crank (7) of the rotating shaft (2); a supply conduit (12), for each cylinder (5), provided with a seal (120) arranged to enable a sealed connection between the supply conduit (12) and the respective cylinder (5).

Each seal (120) comprises: a first ring (121), arranged at an end of the supply conduit (12) and placed in contact with the cylinder (5); a second ring (122), concentric to the first ring (121) and interposed between the supply conduit (12) and the first ring (121), wherein the second ring (122) is coupled by interference with the first ring (121) and is inserted by interference into the supply conduit (12) in such a way as to prevent a rotation of the first ring (121) with respect to the supply conduit (12) around a common axis (X).

A hydraulic machine is provided comprising a cylinder unit (3) having a plurality of cylinders (4a, 4b) which are located on a circle line around an axis of rotation of said cylinder unit (3), a valve plate (6) located at an axial end of said cylinder unit (3) and having a through-going opening (8) for each cylinder (4a, 4b), and a port plate, said valve plate (6) and said port plate resting against each other in sliding contact at a contact face, wherein a pressure in each cylinder (4a, 4b) acts on a pressure area on a side of said valve plate (6) opposite said port plate. In such a hydraulic machine the risk of leaking should be kept small. To this end said pressure area (17) deviates from a circular form.

A hydraulic machine is provided comprising a cylinder unit (3) having a plurality of cylinders (4a, 4b) which are located on a circle line around an axis of rotation of said cylinder unit (3), a valve plate (6) located at an axial end of said cylinder unit (3) and having a through-going opening (8) for each cylinder (4a, 4b), and a port plate, said valve plate (6) and said port plate resting against each other in sliding contact at a contact face, wherein a pressure in each cylinder (4a, 4b) acts on a pressure area on a side of said valve plate (6) opposite said port plate. In such a hydraulic machine the risk of leaking should be kept small. To this end said pressure area (17) deviates from a circular form.

A hydraulic arrangement (1) is provided comprising a pressure exchanger (2) having an axis (3) of rotation, and a booster pump (4), said pressure exchanger (2) and said booster pump (4) being connected to each other. Such a hydraulic arrangement should have a good efficiency. To this end a single connection flange (5) is provided between said pressure exchanger (2) and the booster pump (4).

A hydraulic arrangement (1) is provided comprising a pressure exchanger (2) having an axis (3) of rotation, and a booster pump (4), said pressure exchanger (2) and said booster pump (4) being connected to each other. Such a hydraulic arrangement should have a good efficiency. To this end a single connection flange (5) is provided between said pressure exchanger (2) and the booster pump (4).

The devices comprises a distributor (16) that presents distribution ducts opening out into a radial distribution face (16A), and a distributor-counterpart engaged in each other in such a manner that two main enclosures (18, 20) are provided between their opposite axially-extending faces. The device comprises a cylinder-capacity selector comprising two slides (24, 26) arranged after the other in a bore (22) of the element engaged in the other, to which are connected the main enclosures (18, 20) and at least some of the distribution ducts (30, 31). The slides are able to adopt at least three distinct configurations establishing different connections between the main ducts (18, 20) and the distribution ducts via the main enclosures, in order to be able to obtain at least three distinct operating cylinder capacities.

The disclosure relates to a hydrostatic axial piston machine having a housing, having a drive shaft, to which a flange disc is fastened in a rotationally fixed manner, and having a swash plate, to which a rotor disc, driven by the drive shaft or the flange disc, is rotatably mounted, and having a plurality of displacement units arranged distributed between the flange disc and the rotor disc and around the axis of the drive shaft, each displacement unit comprising a cylinder sleeve and a piston which extends into the cylinder sleeve and has a ball head and a spherical joint head which extends into the cylinder sleeve, wherein during operation, the piston plunges more or less far into the cylinder sleeve.