A hydraulic pump or motor includes a mounting flange that is disposed at the first end of the housing. The mounting flange defines a pair of fastener receiving apertures that are disposed along the X-axis on either side of the shaft. The pair of fastener receiving apertures each define a radius center that are spaced away from each other a X dimension, and a pilot projection extends longitudinally away from the mounting flange, defining a pilot projection diameter. A ratio of the X dimension to the pilot projection diameter ranges from 1.07 to 1.11.

A hydraulic pump/motor includes: a cylinder block rotating about a rotation axis; a piston in a cylinder bore; and a valve plate facing a cylinder port. The valve plate includes: a high pressure port through which hydraulic oil discharged from the cylinder port flows; a low pressure port through which the oil to be sucked into the cylinder port flows; a region disposed between the high and low pressure ports in a circumferential direction of the rotation axis and including a top dead center position facing the cylinder port of the cylinder bore in which the piston moved to a top dead center is disposed; and a residual pressure release port between the top dead center position and the low pressure port in the region. The residual pressure release port includes first and second ports disposed at a positions different from each other in the radial direction of the rotation axis.

The present invention relates to a rotary barrel pump where the pivot connection between barrel (6) and casing (15) is provided by the distinct guide and centering means.

The present invention relates to a rotary barrel pump where the pivot connection between barrel (6) and casing (15) is provided by the distinct guide and centering means.

A hydraulic unit includes an assembly with a hydrostatic positive displacement pump and an electric motor. The positive displacement pump includes a driving shaft configured to be driven by the electric motor. The hydraulic unit also includes an inert mass on which the assembly is rigidly mounted so as to minimize vibration of the assembly and reduce noise emission from the assembly.

A hydraulic unit includes an assembly with a hydrostatic positive displacement pump and an electric motor. The positive displacement pump includes a driving shaft configured to be driven by the electric motor. The hydraulic unit also includes an inert mass on which the assembly is rigidly mounted so as to minimize vibration of the assembly and reduce noise emission from the assembly.

A hydraulic machine includes a first member (1) having a first structure (2) for a hydraulic medium opening in a first interface surface (3) and a second member having a second structure for the hydraulic medium opening in a second interface surface is described, the first interface surface (3) being in contact with the second interface surface, wherein at least one of the members (1) is provided with a support element (6) surrounding the member (1). Such a machine should have a good efficiency. To this end the support element (6) has a strength varying in circumferential direction around the member (1) and/or in thickness direction in a middle region of the member (1).

A hydraulic fracturing pump includes a power end with a plurality of torsion tubes extending between sides of a crankcase housing in which a crankshaft is rotatably mounted. The crankshaft is coupled by piston arms to crossheads disposed to reciprocate along crosshead axes that are perpendicular to the crankshaft. Disposed within the crankcase housing are a plurality of ribs generally perpendicular to the crankshaft and extending from the base of the crankshaft housing to an upper surface of the crankshaft housing. The torsion tubes are generally adjacent the upper surface of the crankcase housing and pass perpendicularly through each of the plurality of ribs and are attached to the ribs to provide rigidity to the power end.

A hydraulic fracturing pump includes a power end with a plurality of torsion tubes extending between sides of a crankcase housing in which a crankshaft is rotatably mounted. The crankshaft is coupled by piston arms to crossheads disposed to reciprocate along crosshead axes that are perpendicular to the crankshaft. Disposed within the crankcase housing are a plurality of ribs generally perpendicular to the crankshaft and extending from the base of the crankshaft housing to an upper surface of the crankshaft housing. The torsion tubes are generally adjacent the upper surface of the crankcase housing and pass perpendicularly through each of the plurality of ribs and are attached to the ribs to provide rigidity to the power end.

The invention relates to a rotary hydraulic machine which includes a casing (2) containing pistons actuated by an input shaft, said casing having a transverse front surface provided so as to engage with a mounting, and a transverse rear surface receiving a rear cover (4) supporting collectors connected to said pistons, the casing comprising side attachment tabs (30, 40) each having an axial bore (32) ending in a rear clamping surface, provided such as to receive an element for clamping said machine to the mounting, characterised in that at least one tab forms an axially elongate pad (40), the height of which is greater than half of the length of said casing included between the front and rear surfaces thereof.