A planetary drive system that aligns four fluid ends for a pump or four compressor cylinders in the same plane, allowing for four fluid ends/compressor cylinders to be driven by one rotation of the pump's motor. Additionally, the planetary drive system is stackable to allow, for example eight, twelve, or other multiples of fluid ends or compressor cylinders to be driven while minimizing any reduction in output pressure. The chemical injection pump also includes threaded vents on the fluid ends to capture chemicals primed through the valves to avoid spillage and waste during the priming process. The air compressor cylinders also include pistons with enhanced vacuum actuation under a flexible inlet (e.g. flapper inlet).

A planetary drive system that aligns four fluid ends for a pump or four compressor cylinders in the same plane, allowing for four fluid ends/compressor cylinders to be driven by one rotation of the pump's motor. Additionally, the planetary drive system is stackable to allow, for example eight, twelve, or other multiples of fluid ends or compressor cylinders to be driven while minimizing any reduction in output pressure. The chemical injection pump also includes threaded vents on the fluid ends to capture chemicals primed through the valves to avoid spillage and waste during the priming process. The air compressor cylinders also include pistons with enhanced vacuum actuation under a flexible inlet (e.g. flapper inlet).

The invention provides a fluid working machine comprising: a crankshaft (2) which is rotatable about an axis of rotation (3); adjacent first and second groups (5, 6, 8, 10) of valve cylinder devices (13) spaced from each other about the axis of rotation (3), one or each of the first and second groups (5, 6, 8, 10) of valve cylinder devices having first, second and third valve cylinder devices (13) arranged about and extending outwards with respect to the crankshaft (2), the first and third valve cylinder devices being axially offset from each other, the second valve cylinder device being axially offset from the first and third valve cylinder devices and the second valve cylinder device being offset from the first and third valve cylinder devices about the axis of rotation, wherein the second valve cylinder device has an axial extent which overlaps with the axial extent of one, or the axial extents of both, of the first and third valve cylinder devices.

The invention provides a fluid working machine comprising: a crankshaft (2) which is rotatable about an axis of rotation (3); adjacent first and second groups (5, 6, 8, 10) of valve cylinder devices (13) spaced from each other about the axis of rotation (3), one or each of the first and second groups (5, 6, 8, 10) of valve cylinder devices having first, second and third valve cylinder devices (13) arranged about and extending outwards with respect to the crankshaft (2), the first and third valve cylinder devices being axially offset from each other, the second valve cylinder device being axially offset from the first and third valve cylinder devices and the second valve cylinder device being offset from the first and third valve cylinder devices about the axis of rotation, wherein the second valve cylinder device has an axial extent which overlaps with the axial extent of one, or the axial extents of both, of the first and third valve cylinder devices.

A prime mover and a plurality of hydraulic actuators, a hydraulic machine having a rotatable shaft in driven engagement with the prime mover and comprising working chambers, a hydraulic circuit between working chambers of the hydraulic machine and the hydraulic actuators, each working chamber of the hydraulic machine comprising a low-pressure and high-pressure valves regulating the flow of hydraulic fluid between the working chamber and a corresponding low-pressure manifold and a high-pressure manifold. The hydraulic machine being configured to actively control the low-pressure valves of the working chambers to select the net displacement of hydraulic fluid by each working chamber on each cycle of working chamber volume, and thereby the net displacement of hydraulic fluid by the working chambers, responsive to a demand signal, wherein the apparatus further comprises a controller configured to calculate the demand signal in response to a measured property of the hydraulic circuit or actuators.

A fuel pump for an internal combustion engine is provided comprising a barrel including a central bore having a longitudinal axis, a plunger disposed partially in the central bore and movable along the longitudinal axis, a spring retainer, a first coil spring having a proximal end in contact with a first section of the barrel and a distal end in contact with the spring retainer to urge the spring retainer into engagement with a tappet assembly, an extender element coupled to the plunger, and a second coil spring having a proximal end in contact with a second section of the barrel and a distal end in contact with the extender element to urge the plunger toward the spring retainer, wherein the extender element includes a counter-bore to couple the extender element to the plunger.

A hydraulic apparatus has a plurality of pump modules each of which is formed by a plurality of working chambers having a common high pressure manifold. A connecting circuit switchably connects pump modules to first and second hydraulic circuit portions to allocate capacity as first and second demands for hydraulic fluid vary. In an apparatus which may have two or more connecting circuit outputs, valves may be controlled or working chamber pumping cycles made inactive to facilitate the reallocation of a pump module from one output to another, and a control strategy addresses pump module allocation when the demands for hydraulic fluid exceed available capacity.

A fluid end of a pump includes a body that defines a suction bore, a discharge bore, and a plunger bore. A first central longitudinal axis extends through the suction bore, the discharge bore, or both. A second central longitudinal axis extends through the plunger bore. A chamber is defined at an intersection between the suction bore, the discharge bore, and the plunger bore. An interior surface of the body that at least partially defines the chamber comprises a first wall portion that is at least partially planar and oriented at an angle that is less than or equal to 15 from perpendicular to the first central longitudinal axis.

A method includes determining a rotational position of a crankshaft in a multiplex pump from one or more sensors disposed on the crankshaft, determining a position of each of a plurality of pistons along a corresponding pump bore in relation to a total stroke length of each piston and a connecting rod length, calculating an individual theoretical displaced volume of fluid for each of the pump bores in the multiplex pump based on the rotational position of the crankshaft, and summing the individual theoretical displaced volumes to determine a total theoretical pumped volume by the multiplex pump. A calibration method includes determination of the multiplex pump efficiency versus speed and discharge pressure, and the effect of pump leakage and valve closing delay on the pump efficiency. Verification of the pump performance and efficiency may be controlled during pumping to insure the validity of the last calibration data set.

An oil-free compressor for a rail vehicle includes a compressor housing, a first low pressure piston cylinder supported in the compressor housing, a second low pressure piston cylinder supported in the compressor housing, a first high pressure piston cylinder supported in the compressor housing, a second high pressure piston cylinder supported in the compressor housing, and a crankshaft assembly supported by the compressor housing and linked to pistons of the piston cylinders by respective connecting rods. The first and second low pressure piston cylinders and the first and second high pressure piston cylinders are positioned in an X-shaped configuration around an outer circumference of the compressor housing. The first and second high pressure piston cylinders are configured as first and second lower legs of the X-shaped configuration, and the first and second low pressure piston cylinders are configured as first and second upper legs of the X-shaped configuration.