Changing a cumulative pumping rate of multiple pump units by adjusting individual pumping rates of the pump units, wherein each temporary dip or spike of an individual pumping rate of one of the pump units is automatically offset by a predetermined temporary adjustment of an individual pumping rate of another one or more of the pump units to thereby reduce effects of the temporary dip or spike on the cumulative pumping rate of the pump units.

Pump, in particular a high-pressure fuel pump, having at least one pump element (10) which has a pump piston (12) which is driven in a reciprocating movement by way of a drive shaft (14) with at least one cam (16; 160) and delimits a pump working chamber (24) which can be filled with delivery medium via an inlet valve (26) during the suction stroke of the pump piston (12). The at least one cam (60; 160) of the drive shaft (14) is a multiple cam with a plurality of cam delivery regions (16a, 16b) for the delivery strokes of the pump piston (12), or a plurality of single or multiple cams (160) with in each case at least one cam delivery region (160a, 160b) for the delivery strokes of the pump piston (12) are provided which are arranged next to one another in the direction of the rotational axis (15) of the drive shaft (14). The cam profiles of the cam delivery regions (16a, 16b) of the at least one multiple cam (16) or the cam profiles of the cam delivery regions (160a, 160b) of the single cams (160) are of different configuration.

A hydraulic pump (6) comprising: a housing (20) having first and second inlets (100a, 100b) and first and second outlets (102a, 102b); a crankshaft (4) extending within the housing (20) and having axially offset first and second cams (62, 64); first and second groups (30, 32) of piston cylinder assemblies provided in the housing (20), each of the said groups (30, 32) having a plurality of piston cylinder assemblies having a working chamber of cyclically varying volume and being in driving relationship with the crankshaft (4); one or more electronically controllable valves (40) associated with the first and second groups (30, 32); and a controller (70) configured to actively control the opening and/or closing of the said electronically controllable valves (40) on each cycle of working chamber volume to thereby control the net displacement of fluid by the first and second groups (30, 32), wherein at least the first group (30) comprises a first piston cylinder assembly in driving relationship with the first cam (62) and a second piston cylinder assembly in driving relationship with the second cam (64), and wherein the first group is configured to receive working fluid from the first inlet (100a) and to output working fluid to the first outlet (102a) and the second group is configured to receive working fluid from the second inlet (100b) and to output working fluid to the second outlet (102b).

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 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.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

An injection moulding system, water jet cutting machine or other industrial system has a synthetically controlled variable displacement fluid working machine which outputs hydraulic fluid to one or more fluid consumers, such as rams or hydraulic motors, through hydraulically stiff fluid retaining volumes and receives hydraulic fluid back from one or more fluid consumers through the same or other said hydraulically stiff fluid retaining volumes. Individual piston cylinder assemblies can be allocated to different outputs. There may be no valve between the machine and the consumers. A working chamber of the machine can be caused to undergo a motoring cycle to enable the machine to output more power than is received from a motor driving the machine. An accumulator can be used to provide a source of hydraulic compliance. The machine can be controlled using pressure control, flow control, feed forward control or variable power/variable power limit control.

A fuel pump includes a cylinder that forms a compression chamber which pressurizes a fuel, a plunger that compresses the fuel in the compression chamber, a cam that pushes the plunger, and a driven gear that engages a driving gear to transmit a rotational driving force. A profile of the cam is configured such that a peak arrival range is half or less of a compression range. Cam speed is obtained by differentiating a lift amount of the plunger by a rotation angle of the cam, the compression range is an angle range during which the plunger is pushed in the direction of compressing the fuel, and the peak arrival range is an angle range from a start of the compression range until a most retarded position of a peak of the cam speed.

The device comprises an internal distributor to be disposed in a casing portion (10A), and comprising a body (15) that has an outside axial face (15B) provided with two grooves (17, 19) respectively for feed and for discharge. The distributor has distribution ducts (23A, 23B, 23C) that open out in a distribution radial face and a cylinder capacity selector that comprises a slide (50) suitable for being moved in an axial bore (53) for connecting the distribution ducts to one or the other of the grooves. The device further comprises a control chamber (52) provided between a first end wall (15′) of the bore and the first end (50A) of the slide, and an opposing spring (55) disposed in a return chamber (52′) situated at the second end (53″) of the bore and closed, at the end closer to the distribution face (15A), by a second end wall (55′) of the distributor.

The device comprises an internal distributor to be disposed in a casing portion (10A), and comprising a body (15) that has an outside axial face (15B) provided with two grooves (17, 19) respectively for feed and for discharge. The distributor has distribution ducts (23A, 23B, 23C) that open out in a distribution radial face and a cylinder capacity selector that comprises a slide (50) suitable for being moved in an axial bore (53) for connecting the distribution ducts to one or the other of the grooves. The device further comprises a control chamber (52) provided between a first end wall (15′) of the bore and the first end (50A) of the slide, and an opposing spring (55) disposed in a return chamber (52′) situated at the second end (53″) of the bore and closed, at the end closer to the distribution face (15A), by a second end wall (55′) of the distributor.