A pump unit for supplying fuel, preferably diesel oil, to an internal combustion engine has at least two cylinders (10), which are formed in at least one head (9), are slidingly engaged by respective pistons (13), and communicate hydraulically with respective fuel inlets (11) in the cylinders (10) via respective interposed intake valves (15) provided with respective valve bodies (16) incorporated in the head (9); the inlets (11) of all the cylinders (10) being closed by a single cover (33) fixed to the head (9).

A pump includes multiple piston chambers each including a piston, an inlet valve and an outlet valve. The pump further includes a first input conduit coupled to the inlet valve of each of a first subset of the piston chambers, a second input conduit coupled to the inlet valve of each of a second subset of the piston chambers, and one or more output conduit coupled to the outlet valve of each of the piston chambers. A mixed fluid stream may be formed by supplying a first fluid to the first subset of piston chambers, supplying a second fluid to a second subset of piston chambers, operating the pump to discharge the first fluid through the first subset of piston chambers and discharge the second fluid through the second subset of piston chambers, and combining the first fluid discharge and the second fluid discharge to form the mixed fluid stream.

A reciprocating pump, in particular a hydraulic pump of a slip-controlled vehicle braking system, includes a step piston, a differential pressure valve, and a pump outlet. The step piston includes a piston step that delimits a stepped space which is in communication with the pump outlet via the differential pressure valve. The piston step is configured such that the step space undergoes suction and displacement in a direction opposite to a displacement space, and in smaller quantities than suction and displacement in the displacement space, such that brake fluid volume flow in the pump outlet is evened out, and such that pressure pulsations are inhibited.

A valve seat at least partially formed of a ceramic material for use in a fracturing pump includes a first body and a second body. The first body is configured to be inserted into a fluid passageway of the fracturing pump. The first body has an outer diameter, D1. The second body extends radially from the first body and has an outer diameter, D2, greater than the outer diameter, D1, of the first body. The second body is at least partially formed of the ceramic material.

Method and apparatus for assessing health of fracturing fluid pump assemblies and other wellsite equipment. For example, predicted data indicative of a first operational parameter of a pump assembly is generated utilizing: a model relating the first operational parameter to each of a plurality of second operational parameters of the pump assembly; and real-time data indicative of each of the second operational parameters. Health of the pump assembly is then assessed based on: the predicted data indicative of the first operational parameter; and real-time data indicative of the first operational parameter.

A hydrostatic radial piston machine includes a radial cylinder block with cylinder bores which extend from an outer circumferential surface of the radial cylinder block into an interior of the radial cylinder block; a number of pistons which corresponds to the number of cylinder bores; a cam ring, and ends of the pistons which face away from the radial cylinder piston block are supported movably on an inner circumferential surface of the radial cylinder block during a rotation of the radial cylinder block; two control plate elements which extend respectively with a face oriented towards the radial cylinder block towards a central plane of the radial cylinder block, which central plane is perpendicular to the rotation axis. Each control plate element includes a bearing portion in which radially acting forces are transferable to a respective mating surface in the housing or housing cover mounted in the housing.

A fluid end (15) for a multiple reciprocating pump assembly (12) includes at least three plunger bores (61) or (91) each for receiving a reciprocating plunger (35), each plunger bore having a plunger bore axis (65) or (95). The fluid end (15) includes suction valve bores (59) or (89), each suction valve bore receiving a suction valve (41) and having a suction valve bore axis (63) or (93), and the fluid end further includes discharge valve bores (57) or (87), each discharge valve bore receiving a discharge valve (43) and having a discharge valve bore axis (63) or (93). The axes of at least one of the suction and discharge valve bores is inwardly offset in the fluid end from its respective plunger bore axis.

In a fuel pump that includes a pump housing (10) that has fuel passages (11a, 11b), a plunger (17) that is movably housed in the pump housing (10), a fuel pressurizing chamber (15) that is formed in the pump housing (10) and draws in fuel via one of the fuel passages (11a) that is on the intake side of the fuel pressurizing chamber (15), pressurizes the fuel that has been drawn in, and discharges the pressurized fuel via the other fuel passage (11b) that is on the discharge side of the fuel pressure chamber (15), in response to movement of the plunger (17), and valve elements (12, 14, 16) that are arranged in the fuel passages (11a, 11b) near the fuel pressurizing chamber (15), each of the valve elements (12, 14, 16) has a reed valve body (41, 42, 43; 74, 75, 76) arranged in the fuel passage (11a) on the intake side of the fuel pressurizing chamber (15) or the fuel passage (11b) on the discharge side of the fuel pressurizing chamber (15); and an operating member (21) that applies operating force in at least one of a valve opening direction or a valve closing direction to the reed valve body (41, 42, 43; 74, 75, 76) is provided in the pump housing (10).

A radial piston motor comprises cylinder-piston units arranged in a star shape, a housing, an output shaft, an inner axial housing collar, an outer axial shaft collar, an output flange, an output shaft, and a brake positioned at least in certain sections between the inner axial housing collar and the outer axial shaft collar. The output flange is attached to the output shaft. The output flange is attached to the shaft collar radially outside the shaft collar.

A radial piston motor comprises cylinder-piston units arranged in a star shape, a housing, an output shaft, an inner axial housing collar, an outer axial shaft collar, an output flange, an output shaft, and a brake positioned at least in certain sections between the inner axial housing collar and the outer axial shaft collar. The output flange is attached to the output shaft. The output flange is attached to the shaft collar radially outside the shaft collar.