A connector plate, for mechanically and hydraulically connecting a hydraulic machine with a hydraulic attachment part, includes a plurality of hydrostatic connector recesses. Each recess has a first side that includes a first orifice opening to the hydraulic attachment part, and a second side with a second orifice opening to the hydraulic machine. The plurality of orifices are arranged so as to open in a substantially axially parallel manner with respect to a drive shaft of the hydraulic machine. A hydraulic machine includes such a connector plate, and a hydrostatic unit includes such a hydraulic machine and a hydraulic attachment part.

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 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.

A piston pump includes a ported member that is moveably disposed within an internal space of a housing between a rotating group and the housing. The ported member includes a first face facing the rotating group and a second face facing a fluid inlet and outlet. The ported member includes an intake port and a discharge port. Moreover, the ported member includes a balance aperture configured to pass fluid between the biasing member and a pump chamber as the rotating group rotates within the internal space such that the biasing member biases the ported member toward a balanced position within the internal space. The balance aperture has a rim at the first face. The rim is clefted at a relief feature of the first face. The relief feature is recessed into the first face.

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.

An inlet baffle chamber (40) is provided in the port cover (26) of a piston pump. The inlet baffle chamber (26) fluidly connects a compressed piston chamber to an adjacent lower pressure piston chamber while the lower pressure piston chamber is in the suction cycle and separately receiving fluid from an inlet manifold (38) of the port cover (26). Instead of de-compressing high pressure fluid directly to pump's inlet (36) as in prior art pumps, the inlet baffle chamber (40) directs fluid to the next piston that is already in the suction cycle.

An inlet baffle chamber (40) is provided in the port cover (26) of a piston pump. The inlet baffle chamber (26) fluidly connects a compressed piston chamber to an adjacent lower pressure piston chamber while the lower pressure piston chamber is in the suction cycle and separately receiving fluid from an inlet manifold (38) of the port cover (26). Instead of de-compressing high pressure fluid directly to pump's inlet (36) as in prior art pumps, the inlet baffle chamber (40) directs fluid to the next piston that is already in the suction cycle.

A pump and motor assembly (20) includes a centrifugal pump (30), a bent axis hydraulic pump 58, and a wet-type drive motor (228). The motor has a rotor and a stator that are submerged in hydraulic fluid for full lubrication and cooling. A drive shaft 66 is driven by the motor. The centrifugal pump has a rotatable impeller (50) for pumping hydraulic fluid from an inlet (48) to the bent axis hydraulic pump. The centrifugal pump also pumps fluid to the motor for lubrication and cooling. The bent axis hydraulic pump pumps the fluid and discharges the fluid from the system. The centrifugal pump and the bent axis hydraulic pump are rotatable along a common rotational axis R1 that is angled relative to the rotational axis R2 of the drive shaft.