Abstract: An oil free screw compressor having a low-pressure stage compressor body and a high-pressure stage compressor body. Power of a motor driven by an inverter is transmitted to the compressor bodies through gears. A low-pressure stage blow-off two-way valve is provided in a pipe branching off midway an air pipe connecting between the high-pressure stage compressor body and the low-pressure stage compressor body, and a high-pressure stage blow-off two-way valve is provided in a pipe branching off from a discharge air pipe provided on a discharge side of the high-pressure stage compressor body. During no-load operation, a controller gives a command to the inverter to make the rotational speed of the motor a set lower limit rotational speed, and also gives an open command to the low-pressure stage blow-off two-way valve.

Abstract: The invention is a two-phase compression device and a process which provides energy to fluids including an essentially liquid fluid and an essentially gaseous fluid or a fluid having a liquid phase and a gas phase, at least one of the fluids or phases being miscible in at least one other of the fluids or phases which allows mixing of the fluids or phases. A device in accordance with the invention includes at least one two-phase compression element having at least one inlet stage and at least one outlet stage, each one of the stages having an impeller and a diffuser, which mixes the essentially liquid fluid and the essentially gaseous fluid or the phases and which provides energy to each of the essentially liquid and gaseous fluids or phases with the mixture provided from the at least one two-phase compression element being a pressurized liquid or essentially a pressurized liquid.

Abstract: A two-stage marine fuel pump (10). A first pump stage (S1) has a fuel inlet (24) and a fuel outlet (26). A second pump stage (S2) has a separate fuel inlet (28) and fuel outlet (30). Each pump stage is stand alone such that while the outlet of the first pump stage can be routed to the inlet of the second pump stage, the pump can be otherwise configured. In these other configurations, there is one path for routing fuel to the fuel inlet of the first pump stage and from the outlet thereof, and a separate path for routing fuel to the inlet of the second pump stage and from the outlet thereof. In these alternate configurations fuel pumped from the first stage of the pump is delivered other than to the fuel inlet of the second pump stage, and fuel supplied to the inlet of the second pump stage is delivered other than from the fuel outlet of the first pump stage.

Abstract: A high pressure fluid pump 10 supplies fluids to a water blasting or cutting gun 14. The pump 10 is preferably of the in-line type, wherein both an inlet check valve 60 and a discharge check valve 62 move linearly along the axis 40 of the plunger 30 during a complete pumping cycle. A plurality of compression rods 42 are spaced circumferentially about a plunger housing 24, and press the plunger housing into sealing engagement with a suction valve seat 56, press the suction valve seat into sealing engagement with a pump discharge housing 36, press the pump discharge housing into sealing engagement with a discharge end plate 38. Seal ring 66 is provided for sealing between a front planar face 114 of the suction valve seat and a rear planar face 112 of the plunger housing. A weep path 116 extends radially outward from the seal ring 66 to release fluids which pass by the compressible seal ring.

Abstract: The invention is a two-phase compression device and a process which provides energy to fluids including an essentially liquid fluid and an essentially gaseous fluid or a fluid having a liquid phase and a gas phase, at least one of the fluids or phases being miscible in at least one other of the fluids or phases which allows mixing of the fluids or phases. A device in accordance with the invention includes at least one two-phase compression element having at least one inlet stage and at least one outlet stage, each one of the stages having an impeller and a diffuser, which mixes the essentially liquid fluid and the essentially gaseous fluid or the phases and which provides energy to each of the essentially liquid and gaseous fluids or phases with the mixture provided from the at least one two-phase compression element being a pressurized liquid or essentially a pressurized liquid.

Abstract: A vacuum pumping system for use with a process chamber. The pumping system has a first vacuum pump whose inlet is adapted for communication via a first line with a chamber outlet and a second vacuum pump whose inlet is adapted for communication via a second line with a first pump outlet. A third line containing a throttle valve is linked to the first and to the second lines in parallel to the first vacuum pump to enable variable amounts of gas to flow through the throttle valve from the second line to the first line depending on the position of the throttle valve.

Abstract: A cryogenic rotary pump for pressurizing a flow of a cryogenic liquid and for dividing the flow into a first lower pressure and a second higher pressure stream has a series of pumping chambers. A single rotary drive shaft carries a rotary inducer located in the chamber, a first impeller in the chamber, and a second impeller in the chamber. A liquid receiving chamber is located intermediate the pumping chambers. A first outlet from the pump for the first lower pressure stream is contiguous to the chamber and a second outlet is provided for the second higher pressure stream. The pump may serve to pressurize a flow of unboiled liquid oxygen from a sump of a lower pressure column of a double column also having a higher pressure column.

Abstract: The invention relates to a fuel pump assembly having a low-pressure region (ND) with at least one low-pressure pump-and a high-pressure region (HD) with at least one regulated-quantity high-pressure pump, which pumps a quantity of fuel required to compensate for the quantitative balance in the high-pressure region, the quantity regulation being effected via a metering unit which is disposed between the low-pressure pump and the high-pressure pump. In order, by simple and sturdy means with high availability and a long service life, to prevent the fuel quantity in correctly pumped by the metering unit at certain operating points from reaching the high-pressure region, the invention proposes that the pumping flow of the low-pressure pump is greater than the pumping flow of the high-pressure pump; that a fuel return line branches off between the metering unit and the high-pressure pump and discharges into the inlet of the low-pressure pump; and that a control element is disposed in the return line.

Abstract: A multi-stage pump has a housing defining a plurality of stages each having an internal rotor enclosure with each enclosure having a non-pumping inlet and outlet. A plurality of rotor assemblies are operatably contained in housing extending through all of the stages. The rotor assemblies and rotor enclosures are shaped to provide a smaller inlet volumetric delivery rate at the last (downstream or outlet) stage than at the first (upstream or inlet) stage. A plurality of fluid lines connect the non-pumping chambers to enable the pump to handle liquid so that, as the rotor assemblies are rotated, a fluid stream entering the pump inlet is subjected to a pumping action to transport the fluid stream to exit through the pump outlet.

Abstract: An on-off valve is connected between a high-pressure pump and a low-press pump and is sized to be rapidly activated during the cranking stage of an internal combustion engine. After actuating the on-off valve, surplus fuel is drained into an inner chamber of the high pressure pump. A solenoid valve is further provided between the low-pressure pump and the on-off valve to automatically cut off the supply of fuel to the on-off valve in the event of an engine failure. The apparatus is beneficial to reduce variation in the fuel supply of the low pressure pump during engine start-up and steady-state operation.

Abstract: A ball screw pump assembly includes a pump body having an axial bore defining a travel chamber and a pressure chamber. An input port and an output port are formed in the pressure chamber. A ball screw is provided in the travel chamber. A piston is connected to the ball screw and slidably extends into the pressure chamber as the ball screw is rotated. The piston divides the pressure chamber into an input chamber having a maximum volume and an output chamber having a maximum volume which is less than the maximum of the input chamber. The ball screw pump assembly can be used in a vehicular braking system.

Abstract: A gas ballast system for a multi-stage positive displacement pump in which a first stage includes at least one positive displacement pump stage, is equipped with an inlet valve and an outlet valve, and is connected with the following stage by an intermediate vacuum chamber, with the gas ballast system including a first conduit for supplying gas into the intermediate vacuum chamber, and a second conduit for supplying gas from the intermediate vacuum chamber into a pump chamber of the first stage or to a suction region of the first stage.

Abstract: A high pressure hydraulic pump apparatus constituting a two-stage pressurizing hydraulic booster combining a pair of plunger pumps. The first and second pumps are driven into a push-pull synchronous operation at the equal stroke with each other. The per-stroke displacement of the first pump is greater than that of the second pump. The first pump draws by self-suction the liquid from a reservoir while the second pump is on the pressurizing and delivery stroke. When the first pump is on the delivery stroke, the liquid pressurized to a certain intermediate pressure by the first pump is sucked into the second pump. During the next reverse stroke the second pump further pressurizes and discharges the liquid while the first pump effects the suction stroke.

Abstract: A vacuum apparatus including at least one vacuum pump having at least one stage and high-vacuum and fore vacuum connections, and a connection line communicating a point located between the high vacuum and fore vacuum connections with the high vacuum connection; and a method for controlling a suction speed of the at least one vacuum pump.

Abstract: Difficulties in adapting centrifugal pumps for use as fuel pumps for turbine powered aircraft are avoided in a system including a centrifugal volute pump (22) on a common shaft (18) with a regenerative pump (24). A pressure responsive throttling valve (46) is connected to the inlet (50) of the regenerative pump (24) so as to cause the regenerative pump (24) to provide fuel at a desired, substantially constant pressure while a check valve (80) is connected to the outlet (72) of the centrifugal volute pump (22) to allow flow from the volute (72) but not the reverse. The outlet side of the check valve (80) can also be selectively connected to the outlet (84) of the regenerative pump (24) so that when the pumps are rotating relatively slowly, the regenerative pump (24) will pump fuel at the desired, substantially constant pressure and, as rotational speed increases, the check valve (80) will open when the centrifugal volute pump (22) is pumping fuel at or about the desired substantially constant pressure.

Abstract: A main fuel tank in an automotive vehicle contains a reservoir in which is located a two-stage electrically operated pump. The first stage is a rotary side lateral pump which draws fuel from the main tank and delivers it to the reservoir. The second stage is a rotary turbine pump which draws fuel from the reservoir and delivers it to the vehicle engine. The reservoir has overflow restriction means which allows air to vent while the reservoir is filling with fuel but which restricts fuel flow when the reservoir is full. This creates pressure in the reservoir to create back pressure against and shut down fuel flow from the first stage pump and also increase pressure on the fuel inlet of the second stage pump thus increasing the efficiency of the second stage fuel pump.

Abstract: A reagent pump assembly for metering precise volumes of fluids, such as reagent, for an analytical instrument, such as a clinical hematology or flow cytometer instrument. The assembly includes a multilayer block having a plurality of diaphragm pumps interposed between two of the layers, controlled by application of one of vacuum or pressure, in sequence, to fill the reservoirs and expel the contents of the pump. One-way check valves are used to control the fluid flow from the reservoirs of fluids to the fluid outlet ports. The fluid outlet ports may be directly coupled to fluid inlet ports of a compatible unified flow circuit, which contains reaction chambers and a plurality of sample aliquots. Thus, the reagent pump assembly can be used to combine and mix a sample aliquots with a precise amount of reagent in a reaction chamber, preparatory for analyzing the reaction mixture.

Abstract: An aspiration and irrigation system of an ophthalmologic device for performing surgical operations on an eye of a living being, includes an irrigation unit for conducting a fluid under pressure to the eye via a first passageway, and an aspiration unit for simultaneous removal of fluid and/or tissue from the eye via a second passageway. The aspiration unit includes a two-stage pump system with a primary vacuum pump producing suction to effect a withdrawal of fluid and/or tissue from the eye through the second passageway and a secondary vacuum pump positioned downstream of the primary pump in a third passageway in communication with the second passageway, for boosting the suction pressure produced by the primary pump.

Abstract: A vacuum pumping stand for the cyclic pumping-down of containers and for maintaining an operating vacuum in the containers, for the pumping-down of the container. The vacuum pumping stand has a first and a second vacuum pump which are arranged in series and form a first and a second pumping stage. The first vacuum pump is a radial flow compressor with a controllable throttle which is located in the intake pipe to the first vacuum pump. The second vacuum pump is a rotary compressor or a water ring pump. The second vacuum pump is located in a vacuum pipe in parallel to an outlet pipe of the first vacuum pump and is connected with its inlet at a branch-off with the outlet pipe. A control part is situated in each of the outlet pipe and the vacuum pipe downstream of the branch-off for directing the delivered volume at higher pressures from the first vacuum pump directly or at lower pressures from the first vacuum pump by way of the second vacuum pump 13 to the outlet 10 of the vacuum pump stand.

Abstract: A cryogenic pump is disclosed for pumping liquified gas from one container to another container or a point of use. The pump comprises a series of chambers and coupling valves for progressively pumping a liquified gas from an inlet end located within and adjacent to the bottom of the container to an outlet conduit. The pump arrangement allows the container to be substantially emptied thereby avoiding waste of the contained liquified gas.

Abstract: A fuel pump structure which includes an electrically driven rotor in a sealed housing which has an inlet and an outlet. A single rotor in the housing has three operating areas. At the outer periphery are vanes operating in an annular sweep channel as a second stage, high pressure regenerative pump which discharges to the housing outlet. Radially within the outer periphery are two radially spaced series of blades forming axial passages in the rotor. The first and outer series of blades operate under a lateral channel to form a first or primary stage pump delivering to a central swirl chamber above and below the rotor. The second and inner series of blades and axial passages allow passage through the rotor to the lower swirl chamber which has a tangential outlet directed to the inlet of the regenerative second stage pump. The base of the lower swirl chamber has a central vapor outlet to allow vapor to leave the fuel which is entering the high pressure pump.

Abstract: A secondary pressure relief valve assembly is coupled to a cryopump relief valve for reducing the gas load on the cryopump. The pressure relief valve assembly comprises a main housing mounted to a crypoump exhaust conduit enclosing that portion of the cryopump valve typically exposed to the external environment. A second relief valve is mounted to the main housing and operates in series with the cryopump valve to exhaust pressurized gases from the cryopump during regeneration. A pump is coupled to a port on the main housing and maintains a pressure within the main housing which is less than the pressure of the external environment. As such, the pressure differential across the cyropump valve is reduced. Since the leakage and permeation gas loads are linearly related to the pressure differential, they are correspondingly reduced.

Abstract: A secondary pressure relief valve assembly is coupled to a cryopump relief valve for reducing the gas load on the cryopump. The pressure relief valve assembly comprises a main housing mounted to a cryopump exhaust conduit enclosing that portion of the cryopump valve typically exposed to the external environment. A second relief valve is mounted to the main housing and operates in series with the cryopump valve to exhaust pressurized gases from the cryopump during regeneration. A pump is coupled to a port on the main housing and maintains a pressure within the main housing which is less than the pressure of the external environment. As such, the pressure differential across the cyropump valve is reduced. Since the leakage and permeation gas loads are linearly related to the pressure differential, they are correspondingly reduced.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine has an injection pump supplied with fuel by a low pressure feed pump through an adjustable throttle. A fluid pressure operable piston is movable against the action of a spring to control the timing of delivery of fuel by the injection pump. Fuel under pressure is applied to the piston through a first fixed orifice from the feed pump. A second fixed orifice and a variable orifice are connected in series between a drain and the downstream side of the first fixed orifice. In parallel with the first fixed orifice is a constant pressure drop valve which maintains the pressure drops across the first fixed orifice substantially constant when the pressure drop has risen to a predetermined value.

Abstract: In a fuel delivery apparatus including a canister in an automobile fuel tank, an electric fuel pump in the canister having two rotating elements from which three stages of pump operation are derived. A housing of the fuel pump has two cavities in which the two rotating elements are disposed. A first element has a web which divides the corresponding cavity into first and second stage pump chambers. The second element in the second cavity cooperates therewith in defining a third stage pump chamber. When the motor is on, vane pockets on one side of the web in the first pump chamber pump fuel from the fuel tank into the canister. Vane pockets on the other side of the web in the second pump chamber pump fuel from the canister to the third stage pump chamber. The second pump element pumps fuel into the interior of the fuel pump at a high pressure compatible with the requirements of internal combustion engine fuel injection systems. Vapor is separated from the fuel in the second stage pump chamber.

Abstract: A supply passage communicates with the inlet of a first centrifugal pump. A second, smaller centrifugal pump has its outlet connected to a delivery conduit. A valve arrangement is selectively operable to connect the inlet of the second pump either to the output of the first pump or directly to the supply passage, both the inlet and outlet of the first pump being shut off in the latter condition.

Abstract: A two stage dry primary pump comprises, in a single common stator: a screw pump at its low pressure end; and a fluid viscous effect, single rotary screw gas exhaust pump at its high pressure end; with a link duct providing communication between the screw pump and the viscous effect, single rotary screw gas exhaust pump. The invention is applicable to vacuum pumps.

Abstract: A pumping system for a heavy oil and sand slurry from a downhole location to the ground surface includes a conventional screw type pump having a rotor and stator. At the bottom of the stator at the inlet thereto is mounted an attachment including a sleeve having a number of slots in the side surface into which the material feeds. Inside the sleeve is mounted a shaft having an auger flight along part of its length. A coupling at the upper end of the shaft connects to the lower end of the rotor and can be engaged and released by rotation of the rotor. The auger flight assists in forming the materials including any excess sand into a suitable slurry for feeding to the inlet of the pump. The auger feeds the material more effectively to the inlet thus maximizing efficiency of the pump. The device thus avoids sand blockages which are common problems in pumping systems of this type.

Abstract: A fuel pumping apparatus for supplying fuel to an internal combustion engine comprises a rotary distributor member mounting a pumping plunger slidable in a bore and moved inwardly to discharge fuel from the bore by cam lobes on the internal surface of a cam ring, the cam lobes acting on the plunger through a cam follower. A valve is provided which at a predetermined position during the inward movement of the plunger, is opened to lower the pressure in the bore and thereby to terminate fuel flow through an outlet. The valve is actuated by the cam lobes either from the cam follower or from the plunger.

Abstract: A metering fuel pump adapted for feeding fuel containing vapor or air to an engine that includes a housing assembly. The metering fuel pump further includes a motor section encased inside the housing assembly for providing the required rotary motion to a two-stage pump section. The speed of the motor section is controlled by a motor controller section that provides a voltage regulated flow of fuel. The two-stage pump section imparts pressure to the fuel and encloses a cyclonic vapor separator section.

Abstract: There is disclosed a metering pump for metering and pumping small volumes of fluid. A continuous member with annular elements carries pumping fluid through a first passageway containing a diaphragm which defines a second passageway. Provision is made for changing the pressure of the pumping fluid being carried through the passageway. This causes the diaphragm to expand into the first passageway drawing fluid to be pumped into one end of the second passageway. The pumped fluid is then carried through the second passageway by movement of the continuous member with annular elements along the first passageway and delivered out of the other end of the second passageway.

Abstract: A fuel injection apparatus having an auxiliary pump for pilot and main injections in internal combustion engines, in which a pilot injection quantity pumped by a low-pressure pump is stored ahead of a pilot injection piston embodied as a pressure piston, which is driven by a following but coaxially disposed intermediate piston, upon pumping by the high-pressure injection pump, and as a result positively displaces the pilot injection quantity. Both pistons are supported in an intermediate element between the connection piece of an injection valve and the nozzle holder of the valve. The intermediate element combines not only the elements for the auxiliary pump but also the leak-off bores from the nozzles with the leak-off removal means of the two-part stepped piston supported therein.

Abstract: A device and method are disclosed for monitoring the cavitation parameters of a positive displacement fuel pump. A flow proportional to the flow of the pump is branched off a supply line to a cavitation venturi at a pressure lower than the supply pressure, while regulating the proportional flow and the venturi so that the latter attains its cavitation range prior to the cavitation of the positive displacement pump. In this range, the pressure at the inlet of the venturi is equal to the critical feeder pressure of the volumetric pump. The difference between the supply pressure of the positive displacement pump and the pressure of the inlet of the venturi is detected and a control signal generated to activate an alarm or increase the pressure of the supply fluid.

Abstract: There is described a pump assembly which, in a unitary structure, comprises an electric pump drive motor and a two stage pump contained within a common housing. The motor drives the first stage of the pump upstream of the second stage which supplies the fuel, by creating a higher output from the first stage, which supply pressure is produced on the suction side of the second stage to maintain the pressure build-up in the pump. An air discharge is provided ahead of the inlet to the suction side of the second stage to dispell gases created in the fuel by the elevated pump pressures.

Abstract: A fuel pumping apparatus includes an injection pump which is supplied with fuel through a passage from a feed pump. A throttle member having a groove is angularly adjustable to determine the rate of fuel flow. For this purpose the groove has variable communication with a port at the end of the passage. The throttle member has a further groove which when the throttle is closed to prevent fuel flow to the injection pump, places the port in communication with a further port connected to a low pressure. This allows fuel to be expelled from the injection pump so that delivery of small amounts of fuel to the engine does not occur when the throttle is closed.

Abstract: A method and an apparatus for operating a fuel supply system, in particular a fuel injection system, in which a fuel supply pump continuously supplies fuel and wherein the excess fuel not required for injection is returned to the fuel reservoir. In order to reduce the average operating power of the pump and thus reduce the average amount of fuel returned to the tank, thereby reducing undesirable temperature increases of the fuel in the reservoir, the system fuel pressure is monitored and maintained at a value substantially equal to a reference value. The electrical power of the fuel supply pump is altered continuously so as to maintain the fuel system pressure at the reference level.

Abstract: A fuel pumping apparatus comprises feed pump supplying fuel to an injection pump. A chamber is located between the two pumps and has an outlet including a restricted orifice extending from the upper end of the chamber through which fuel and air collecting in the chamber can flow. A float is located in the chamber and mounts a valve member which can cooperate with a seating defined about a lower outlet in the lower wall of the chamber. The lower outlet connects with the injection pump and is obstructed if the chamber becomes filled with air to prevent the supply of air to the injection pump.

Abstract: The invention relates to a cryogenic pump for liquid gases which comprises, within a housing, a cylinder connected to the supply of liquified gas through a non return valve and to an overflow duct. A movable piston is displaceble within this cylinder defining a suction chamber and an evacuation chamber and this piston carries a skirt cooperating with a piston rigidly fixed to the frame defining together a compression chamber. This compression chamber is connected through a non return valve to the high pressure output of the pump and to the suction chamber by means of at least one passage provided with a non return valve.

Abstract: Disclosed is a dual pump with priming reservoir assembly for dispensing a fluid chemical at a low flow rate into a substance with which the fluids is to be mixed. It includes adjacent primary and secondary piston-type pumps and a separation chamber or priming reservoir. The primary pump has a discharge capacity in substantial excess of the final dispensing fluid flow rate. The suction side of this pump is connected to a remote source of chemical fluid to be dispensed. The discharge line of the primary pump and the suction side of the secondary pump communicate with the reservoir. The discharge side of the secondary pump is connected to the dispensing line and its output is adjusted to provide the desired, accurately metered dispensing fluid flow.

Abstract: A fuel system for a multi-cylinder engine comprises a plurality of injection nozzles mounted on an engine to direct fuel into respective combustion spaces of the engine. Each nozzle incorporates a resiliently loaded pressure actuated valve member which controls the flow of fuel through an outlet from a fuel inlet. A fuel pump is provided for supplying fuel to the inlets in turn. Pilot pumps incorporated in the nozzles respectively cause a small volume of fuel to be delivered through the respective outlets in advance of the main volume of fuel.

Abstract: A pump assembly for use in fire fighting service is constructed of a single stage main pump and a two stage booster pump connected in series with the discharge of the main pump being connected to a first high flow rate fire fighting application and to the inlet of the booster pump and the discharge of the booster pump being connected to a second low flow high pressure fire fighting application. The impellers for both the main pump and the booster pump are mounted on a common rotating shaft so as to be driven thereby. A flow restriction and conduit means is provided to reduce the pressure on the booster pump seal. A by-pass conduit is arranged to conduct flow from the discharge of the booster pump back to the inlet of the main pump so that whenever the main pump is operated there will be flow through the booster pump to prevent overheating thereof.

Abstract: An improved pump and motor assembly is utilized to regulate a flow of fuel to an internal combustion engine. All of the fluid connections to the pump are connected with one end of the assembly. The pump and motor are both enclosed within a one-piece casing having a tubular side wall which is integrally formed with an end wall. The end section to which all of the fluid connections for the pump are made, is connected across the open end of the tubular side wall. To provide for the removal of vapor bubbles from the fuel, fuel supplied under pressure from the tank flows through an inlet cavity which circumscribes the pump and has an axial extent which is equal to the length of the pump. In addition, a screen at the inlet of the pump itself blocks the flow of vapor bubbles from the inlet cavity to the pump. The forces applied against opposite sides of the moving components of the pump by the inlet fluid are substantially balanced.

Abstract: A method for the ventilation of fuel supply pumps as well as a new type of fuel supply pump are proposed which, particularly in pumps having two pumping stages coupled in series within the housing, serve to secure the ventilation of the first pumping stage. Preferably the first pumping stage is embodied as a lateral channel pump which has a forward anterior base plate. The ventilation bore is arranged axially at first in the base plate and in association with the lateral channel and is preferably formed during manufacture in one piece with the base plate; a reduction of the overly-large diameter of the ventilation bore is effected by the insertion of a reduction part to achieve the flow cross section required for ventilation. The ventilation to the outside of the lateral channel stage takes place via an external connection nozzle on the pump housing, which is secured thereon either axially or radially and can be embodied in one piece therewith as necessary.

Abstract: A supply pump comprising a body having an inlet and an outlet both in fluid communication with an interior region of the body which contains two pistons positioned to reciprocate coaxially and which define three variable volume chambers, one between the two pistons and in fluid communication with the inlet, a second between one piston and the outlet and a third between the other piston and the outlet. The pistons have different working areas, and the piston of larger area carries a check valve which allows fluid flow from the chamber between the pistons to the chamber between the larger piston and the outlet. A regulating spring acts between the body and the smaller piston to urge both pistons against a mechanical drive means including a reciprocable rod carried by a tappet contacting a driven cam. During each forward and reverse stroke of the pistons in response to rotation of the cam, supply fluid is drawn into the pump through the inlet and forced out of the pump through the outlet.

Abstract: A fuel pumping apparatus for supplying fuel to a compression ignition engine comprises a rotary distributor located within a housing and having a transverse bore mounting a pair of plungers which are driven inwardly as the distributor rotates, to displace fuel through an outlet. The apparatus includes a pilot pump including a plunger which is operable by actuating means to displace fuel from a pilot pump chamber in advance of the delivery of fuel by the main plungers. The displacement of fuel by the pilot plunger effects an initial supply of fuel to the engine for the purpose of pilot injection.

Abstract: A fuel pumping apparatus comprises a piston movable by fluid pressure to vary the timing of delivery of fuel to an associated engine. Valve means provides fuel under pressure which varies in accordance with the speed at which the engine is driven and fuel at this pressure is applied to the piston through a first fixed orifice. A second fixed orifice is connected to the downstream side of the first orifice and a variable orifice is provided to control the fluid flow through the second orifice. The size of the variable orifice is dependent upon the amount of fuel supplied to the associated engine by the apparatus. In addition a pressure responsive valve is provided which defines a flow path connected in parallel with one of the orifices, the valve being subjected to a fluid pressure within the system.

Abstract: A fuel injection pumping apparatus includes an axially movable member which at one end is acted upon by governor weights and at its other end is acted upon by a spring, the governor weights moving the member in opposition to the spring, the reaction member for the weights comprising a dash-pot containing a further spring and the member being provided with a groove which can register with a port to control the flow of fuel delivered by the pumping apparatus to the associated engine. Also provided on the member is a further groove which is in restricted communication with the groove and which during certain conditions of rapid deceleration of the engine, is brought into communication with the port so as to ensure that under such conditions a restricted flow of fuel takes place to the engine.

Abstract: A fuel injection pumping apparatus includes an injection pump to which fuel is supplied from a feed pump under the control of throttle means. A component of the injection pump is adjustable by the application of fluid pressure to a piston. The fluid pressure is derived by way of a fixed orifice the downstream of which is connected to a cylinder containing the piston, the downstream side of the orifice being connected to a drain by way of a second fixed orifice and a variable orifice is provided which is adjustable with the throttle means and which determines the pressure applied to the piston.

Abstract: A turbomachine plant comprises a gas turbine, a synchronous electrical machine operable as a motor or generator, and a compressor all mounted on the same shafting and adapted to be coupled together for two optional operating modes. In a first operating mode, the gas turbine serves to drive the synchronous electrical machine for generation of electrical power and the compressor is not utilized. In the second operating mode, the synchronous electrical machine operating as a motor serves to drive the compressor for gas compression and the gas turbine is not utilized. When in the first operating mode the compressor is not disconnected by conventional clutch means from the gas turbine-synchronous electrical machine group but rather always remains connected to that group and is arranged by suitable valving so as to rotate in a vacuum type of operation with a power loss which is slight in relation to the gas turbine.

Abstract: The output from the pump chamber of a higher volume piston pump is divided between a return bypass and the pump chamber of a smaller volume piston pump; the piston of the high volume piston pump is periodically raised by a cam to draw fluid into the pump chamber; when this piston is released, a spring forces fluid from the high volume pump chamber; the pump chamber of the small volume pump is connected with the cam such that the volume of the low volume pump chamber decreases, thereby pumping out the fluid in that chamber, when the large volume pump chamber is taking in fluid, and vice versa; appropriate valves ensure that flow is only in the desired direction; adjustment and calibration means are provided for the low volume pump.