This disclosure includes plunger pumps having leak detection systems. Some pumps include a housing having a bore, an inlet, and an outlet, a plunger disposed within the bore and a first seal engaged with the plunger to divide the bore into first and second chambers, the plunger configured to reciprocate within the bore to expel liquid from the first chamber out of the outlet, and a sensor for detecting a presence of liquid in at least a portion of the second chamber. Some pumps have a reservoir for collecting liquid that leaks into the at least a portion of the second chamber, where the sensor is for detecting a liquid level in the reservoir. Some pumps include a second seal engaged with the plunger to divide the second chamber into first and second portions, and the sensor is for detecting a presence of liquid in the second portion.

This disclosure includes plunger pumps having leak detection systems. Some pumps include a housing having a bore, an inlet, and an outlet, a plunger disposed within the bore and a first seal engaged with the plunger to divide the bore into first and second chambers, the plunger configured to reciprocate within the bore to expel liquid from the first chamber out of the outlet, and a sensor for detecting a presence of liquid in at least a portion of the second chamber. Some pumps have a reservoir for collecting liquid that leaks into the at least a portion of the second chamber, where the sensor is for detecting a liquid level in the reservoir. Some pumps include a second seal engaged with the plunger to divide the second chamber into first and second portions, and the sensor is for detecting a presence of liquid in the second portion.

A hydrostatic axial piston pump of swashplate construction, which is also configured to be operated as a motor, has a stationary control plate against which a rotating cylinder drum is tensioned. During operation, a tilting tendency of the cylinder drum arises in the direction of that quadrant of the control plate which is operatively connected to the first part of the displacement stroke of the pistons. The control plate has a supporting device configured for the cylinder drum. The supporting device is arranged adjacent to an outer edge of the control plate in the first quadrant thereof. The supporting device is configured to be formed by a hydrostatically relieved additional field.

An axial piston machine may include a shaft and a housing surrounding at least a portion of the shaft. A cylinder arrangement may be disposed within the housing in a circular manner. The cylinder arrangement may include a plurality of cylinders and a plurality of pistons each extending within each of the plurality of cylinders and may be constructed and arranged to drive the shaft. The plurality of cylinders may each include an expansion volume with an inlet and at least one outlet opening for a working medium. A cylinder head may be provided on the housing and may be constructed and arranged to close the plurality of cylinders of the cylinder arrangement. A cavity may be defined around the shaft in a central region of the cylinder arrangement and may be in operative communication with a plurality of auxiliary outlet openings of the expansion volume of each of the plurality of cylinders via a temporary connection. A cylindrical roller slider may rotate within the cavity in the central region of the cylinder arrangement and may be constructed and arranged to drive the shaft. A temporary connection between the cavity and the expansion volume of each of the plurality of cylinders may be formed by at least one of a channel through the cylindrical roller slider and a recess on an outside surface of the cylindrical roller slider. The recess may extend laterally from a casing of the cylindrical roller slider at a height of the plurality of auxiliary outlet openings in each of the plurality of cylinders and at a distance to the cavity in the central region of the cylinder arrangement.

This plunger pump includes a pressurization chamber that has a tubular inner circumferential wall and a plunger that has a substantially cylindrical outer circumferential surface. The inner circumferential wall has, in a part thereof in a circumferential direction about an axis of the plunger, a suction opening, which communicates with the pressurization chamber and is for introducing a fuel into the pressurization chamber. The inner circumferential wall is formed with an enlarged gap portion having a larger dimension than a dimension, at a position of the suction opening, from the outer circumferential surface of the plunger to an inner circumferential surface of the inner circumferential wall along a radial direction of the plunger, in at least a part of the inner circumferential wall at a position away from the position of the suction opening in the circumferential direction.

An axial piston pump has a rotor rotatable around an axis relative to a swashplate; one or more pistons movable within one or more respective sleeves; a fluid inlet port for the inflow of low pressure fluid, and a fluid outlet port for the outflow of high pressure fluid; and a floating element axially positioned between, on the one side, the inlet and outlet ports and, on the other side, a sealing surface of the rotor. Surfaces of the floating element defining an inlet chamber and the outlet chamber are configured such that, in use, the low pressure fluid and the high pressure fluid act on the defining surfaces to produce a net axial force which the axially slidable floating element applies to the rotor to seal the floating element to the sealing surface of the rotor.

A desmodromic mechanism exhibits reciprocating motion of a pair of cam followers driven by a single cam. The mechanism is useful in a fuel pump that pressurizes a liquid for delivery to a fuel rail of a combustion engine. A desmodromic lever is symmetric about its rotational axis and maintains continuous contact between cam lobes and cam followers for the entirety of each rotational cycle. The mechanism is particularly useful in multi-piston pumps required to deliver higher than normal volumes of liquid fuel, as is the case with low energy density alternatives to diesel fuel.

A desmodromic mechanism exhibits reciprocating motion of a pair of cam followers driven by a single cam. The mechanism is useful in a fuel pump that pressurizes a liquid for delivery to a fuel rail of a combustion engine. A desmodromic lever is symmetric about its rotational axis and maintains continuous contact between cam lobes and cam followers for the entirety of each rotational cycle. The mechanism is particularly useful in multi-piston pumps required to deliver higher than normal volumes of liquid fuel, as is the case with low energy density alternatives to diesel fuel.

This disclosure includes packing stacks for pumps, pumps having the same, and related methods. Some packing stacks include male and female adapter rings and one or more V-rings, each including a concave surface and an opposing convex surface and configured to be disposed between the male and female adapter rings with the concave surface facing the former and the convex surface facing the latter. In some packing stacks, the male adapter ring includes a body and a ridge projecting from the body, the ridge configured to overlie a central area of the concave surface of the V-ring that is closest to the male adapter ring and less than 40% of the concave surface. In some packing stacks, the male adapter ring has a non-cylindrical interior passageway configured to facilitate fluid flow past the male adapter ring when a plunger is disposed therethrough.

A water part module (12) for attaching to a piston pump, which comprises a support unit (14) that can be releasably attached to the piston pump and at least respectively one suction module (16) and pressure module (18) that is or can be releasably connected to the support unit (14), wherein the support unit (14) and the or each suction module (16) and the or each pressure module (18) are designed such that the suction and pressure modules (16, 18) are interchangeable with one another, wherein each suction and pressure module (16, 18) has at least two planed side faces of which one acts as the lower connection face and a side face adjoining the lower connection face acts as the lateral connection face, and wherein a duct (26) inside the respective suction and pressure module (16, 18), which can be closed and opened by means of a valve (34) in the respective suction and pressure module (16, 18), ends on one side in the lower connection face and on the other side in the lateral connection face.