Abstract: A pump assembly comprises a base, a cam, a cylinder, a piston, and a shim clip. The cam rotates about a rotational axis with respect to the base. The cylinder attaches to the base, and has an inlet port and an outlet for fluid. The piston is reciprocally driven by rotation of the cam to draw fluid into the cylinder through the inlet port during a fill stroke, and to close the inlet port and pump fluid in the cylinder toward the offset during a pump stroke. The shim clip is removably insertable between the cylinder and the base to increase the distance between the inlet port and the rotational axis.

Abstract: A piston pump includes a main body having an inlet, an outlet, and a chamber fluidly connected to form at least a portion of a first fluid flow path for receiving a flow of fluid therein. The pump also includes a second fluid flow path to provide fluid communication between the chamber and a point upstream of the inlet of the main body. A piston is disposed in the chamber of the main body and reciprocatingly moves therein to cause the flow of the fluid through at least one of the first fluid flow path and the second fluid flow path. An adjustment element is disposed in the main body and configured to adjust an effective flow of the fluid through the first fluid flow path.

Abstract: In order to enable a continuous adjustment of the variable clearance space (1) of a reciprocating compressor (15), a threaded spindle drive with a threaded spindle nut (10) and a threaded spindle (9) is provided as an adjusting device (7), wherein the threaded spindle nut (10) is embodied as a plastic nut (20) with internal thread (24), the plastic nut (20) is arranged with an external thread (23) on an internal thread (22) of a nut carrier (21) of the threaded spindle nut (10), and the thread height (y) of the internal thread (22) of the nut carrier (21) and the thread height (x) of the external thread (25) of the threaded spindle (9) is respectively embodied with 50 to 80% of the radial thickness (d) of the plastic nut (20) and the plastic thickness is at least 15% of the thread pitch (z1) of the internal thread (24) at least in the region of the thread flanks (26) of the internal thread (24) of the plastic nut (20).

Abstract: An element is provided to maintain a clearance gap between a piston and a cylinder wall. In some embodiments, an element is included that is capable of spatial change. In some embodiments, the element is a component such as a clearance ring, a surface bearing, or a segment of a clearance ring or surface bearing. A clearance gap may be maintained by inward and outward motion of the component with respect to a piston assembly and a cylinder wall, where the motion is determined by a balance of forces acting on the component. In some embodiments, an inward force generated by an external gas pressure source is balanced by an outward preload force generated by, for example, a pneumatic piston. In some embodiments, a clearance gap is maintained based on in part on the ratio of inner to outer surface areas of a clearance ring.

Abstract: Disclosed herein are embodiments of inventive multipositioner technology relating to multipositioner apparatus having discrete positioning capability and, relative to each discrete position, incremental positioning capability. As compared with prior art apparatus, embodiments of the inventive technology may afford: operational resolution for larger positional ranges, reduced cylinder length to achieve positioning as desired, enhanced positioning capability and/or robustness of design.

Abstract: A controllable variable volume clearance pocket for reciprocating compressor cylinders is disclosed. The invention includes a device for varying the clearance volume of a variable volume clearance pocket in a controlled manner. The device can be used repeatedly to change the compressor cylinder clearance volume as required to control compressor capacity and power required from the compressor driver. The device is typically mounted on the outer or head end of a reciprocating compressor cylinder, but can also be scaled and configured for use either in conjunction with a variable clearance volume unloader operating over a reciprocating compressor valve pocket or a special port in a reciprocating compressor body.

Abstract: A high pressure pump for use in the injection of liquid chemicals into subsea oil or gas wells, and intended to be positioned in the subsea environment adjacent to the wellhead, comprises a piezoelectric actuator (19) for reciprocating a plunger (22) which acts to compress and expand the effective volume of a pumping chamber (29) having a valved inlet (15) connected to a source of the liquid and a valved outlet (16) to lead the liquid to the well. The device has a minimum of moving parts and in particular avoids the need for any rotating parts and attendant high performance bearings and seals.

Abstract: A reducing agent pump has a pump inlet part and a pump outlet part closing off the pump body at its ends. One or both of the inlet and outlet parts is of two-part construction, with a closure element and another element. The two elements are prestressed relative to one another with a spring element, so that in the event of a pressure which exceeds the spring force of the spring element, a relative movement can be carried out between the two elements of the two-part member. This makes it possible to absorb an increase in the volume of the reducing agent inside the pump body caused by freezing and therefore to prevent damage to the reducing agent pump.

Abstract: Apparatus for controlling a hydraulic circuit to be used for operating hydraulic clutches with a pump (8) connected with a relevant reservoir (88) for the fluid of the hydraulic circuit and comprising a piston (89) sliding within a relevant chamber (80) provided with one or more ports (83, 84) for connection to said reservoir (88), the said piston being so shaped as to close/open the said ports (83, 84) upon its stroke along said chamber (80), apparatus being characterized in that the idle stroke of the piston (89) within said chamber (80) is adjustable through a rotation of the same piston (89) about its longitudinal axis.

Abstract: A medium pump for a motor includes a pump case with a pump cylinder and a pump piston positioned displacaebly in the pump cylinder in the direction of a pump axle. The pump piston rotates about the pump axle by running off an oblique control surface and realizes axial pump movements against the pressure of a first spring. A pump lift adjusting device is removably positioned in a guide placed transversely to the pump axle and fixedly connected with the pump case.

Abstract: A metering pump includes an actuating mechanism, and a plurality of piston cylinders coupled to the actuating mechanism. A first of the cylinders has a working volume that differs from a second of the cylinders. The actuating member is centrally located and the cylinders are arranged radially about the actuating mechanism. The working volume of the cylinders can be varied by adjusting the spacing of the cylinders from the actuating mechanism, thus varying the stroke of pistons housed within the cylinders, and/or by providing the cylinders with different inner diameters. A method of metering fluids includes independently adjusting stroke of a plurality of pistons to adjust the volume of metered fluid, and selecting different cylinder diameters to adjust the volume of metered fluid.

Abstract: A plural component pumping apparatus including a piston and cylinder for each component to be pumped. Reciprocation of the piston in the cylinder draws the component into the cylinder during an intake stroke of the pumping apparatus and exhausts the material from the cylinder during an exhaust stroke of the pumping apparatus. Intake and exhaust valves are provided into the cylinder. Each of the intake and exhaust valve includes a housing oriented outside the cylinder to facilitate repair or replacement of the valves. A pumping motor on each side of the cylinder is coupled to a support and to the piston to move the support and piston relatively toward each other during the exhaust stroke and relatively away from each other during the intake stroke. A position indicator is coupled to the pumping motor. The pumping motor controls sense the position of the position indicator.

Abstract: The invention relates to a piston engine which is essentially comprised of an engine shaft and a set of modules, each of which comprises a cylinder and a piston powered by the engine shaft in the cylinder, each module resulting in vibratory excitation of the engine at a determined fundamental frequency. Rather than introducing phase differences between the various vibratory excitations, as is the case in prior art, the invention introduces a frequency offset between the fundamental frequencies thereof in order to avoid a high-amplitude vibration at a common excitation frequency, arising from the spectral spread thus obtained.

Abstract: A position sensor is provided, particularly a sensor applicable to a linear compressor, for detecting the position of the piston and preventing the latter from knocking against the head located at the end of its stroke. More particularly, there is provided a sensor, particularly one that is employable in detecting the position of a piston of a compressor, the piston being axially displaceable inside a hollowed body, the compressor comprising a valve blade, the blade being positioned between the head and the hollowed body, the sensor comprising a probe electrically connected to a control circuit, the probe being capable of detecting the passage of the piston by a point of the hollowed body and signaling this to the control circuit. An associated compressor employing such a sensor is also provided.

Abstract: A pump (10) has a housing which forms a pump chamber (17) having a wall (18). Inlet and outlet valve assemblies (19, 20) communicate with the chamber (17) and, respectively, allow fluid to be received in, and discharged from, the chamber (17). An armature (27) carries a plunger (28) and is reciprocatably moved by an electromagnetic coil assembly (25). A coil spring (44) biases the plunger (28) toward a stop surface (41) positioned adjacent to the plunger (28). Upon activation of the coil assembly (25), the plunger. (28) is moved against the force of the spring (44) such that a diaphragm (31) carried by the plunger (28) moves into the chamber (17) without engaging the wall (18) to discharge fluid through the outlet valve assembly (20). When the coil assembly (25) is deactivated, the spring (44) moves the plunger (28) toward the stop surface (41) without allowing it to engage the stop surface (41) to draw fluid in through the inlet valve assembly (19).

Abstract: Apparatus and method for controlling an unswept volume in a piston system. The method includes rotating a shaft around a rotation point to drive a piston within a cylindrical volume in a periodic manner, modifying the stroke length of the piston, and moving the center of the shaft relative to the cylindrical volume such that a change in an unswept volume or compression ratio is controlled.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The connecting rod assembly includes a first portion adapted to be connected to the crankshaft, and a second portion adapted to be connected to the piston and movable with respect to the first portion. The connecting rod assembly further includes a locking mechanism disposed between the first and second portions. The locking mechanism includes a rotatable locking element that is configured to lock the second portion at a first position relative to the first portion. Furthermore, the first position corresponds to a first compression ratio of the engine.

Abstract: A hydraulically actuated servo piston and hydraulic advance piston are integrated into the cam follower of a unit pump or injector to provide variable advance for an injection event produced by the pump or injector. The servo piston is nested in the advance piston with fluid passageways in the advance piston selectively opened or closed by movement of the servo piston. The full pressure of a hydraulic pump is available to the advance piston for powering the advance function, while stepwise reduced levels of hydraulic pressure from the same hydraulic pump are applied to control movement of the servo piston. A damping orifice restricts flow of hydraulic fluid to and from the servo piston.

Abstract: There is disclosed a high-pressure compressor comprising a compression mechanism for reciprocating/driving a piston with respect to a conventional cylinder by rotation of a motor and compressing an operating fluid sucked by this driving to generate the high-pressure operating fluid according to improvements in a piston shape, positions of a cylinder operation surface and the piston, specifics shapes of the cylinder and piston, and connecting constitution of the piston to a connecting rod, which solves problems such as occurrence of wear on a cylinder inner surface by displacement of the piston, size enlargement by an increase of a removal capacity, difficulty in processing the piston and connecting rod, and a large top clearance.

Abstract: A connecting rod assembly is provided for varying a compression ratio of an internal combustion engine having a crankshaft and a piston. The connecting rod assembly includes a first portion adapted to be connected to the crankshaft, and a second portion adapted to be connected to the piston and movable with respect to the first portion. The connecting rod assembly further includes a locking mechanism disposed between the first and second portions. The locking mechanism includes a rotatable locking element that is configured to lock the second portion at a first position relative to the first portion. Furthermore, the first position corresponds to a first compression ratio of the engine.

Abstract: In a free piston machine, initial collisions of the piston with structures at the end of the cylinder are detected and generate a change in the magnitude of a perturbation signal, which is applied to the summing junction of a closed loop feedback control system controlling a piston force. The change is applied in a direction to reduce piston amplitude. In embodiments in which maximization of piston amplitude is desirable, the magnitude of the perturbation signal is also varied in the opposite direction in the absence of collisions to increase piston amplitude of oscillation so that operation then hunts between initial nondestructive collisions and a non-colliding maximum amplitude of piston oscillation.

Abstract: A fuel pump comprises a pumping plunger reciprocable within a plunger bore under the action of a cam drive arrangement. The cam drive arrangement comprises first and second surfaces defining therebetween a chamber, the volume of which can be controlled to control the spacing of the first and second surfaces so as to permit control of the axial length of the cam drive arrangement. The first surface may be defined by a tappet member which acts to transmit a force from the cam drive arrangement to the pumping plunger, the second surface being defined by a piston member which is slidable within a tappet bore formed in the tappet member. The invention also relates to an arrangement for use in a fuel pump comprising a pumping plunger which is reciprocable within a plunger bore under the action of a drive arrangement and a tappet member which is slidable within a further bore provided in a housing for transmitting a force from the drive arrangement to the pumping plunger.

Abstract: A method of calibrating a lost-motion metering pump is disclosed wherein the pump includes a relief port, a movable hollow plunger having a bypass hole which is aligned with the relief port when the plunger is moved to an aligned position and a control rod extending into the hollow plunger. According to one aspect, the method includes the steps of moving the plunger to the aligned position, inserting a gage pin through the relief port and the bypass hole into the plunger, moving the control rod into engagement with the gage pin and fixing the position of the control rod.