Abstract: A device and method for converting electric energy into pneumatic energy and vice versa, which involves: pumping a liquid forming a liquid piston into a conversion chamber in which a quantity of air is trapped until the air reaches a pressure of a compressed air storage vessel; or churning a liquid by expanding the compressed air in a conversion chamber which is filled with a quantity of liquid, in which device or method the pumping or the churning of the water takes place in the same conversion chamber and consecutively in at least two pumping or churning stages, respectively, provided so as to operate in different pressure ranges. The present device and method can be used in particular in the field of converting and storing electric energy.

Abstract: A lubricant pump system may include a lubricant pump controlled by a proportional valve. An actuating unit may be disposed in the lubricant pump and configured to control a delivery output of the lubricant pump. A first pressure chamber and at least one second pressure chamber may be configured to adjust the actuating unit against a spring, wherein the second pressure chamber is smaller than the first pressure chamber. In response to a failure of the proportional valve, the lubricant pump may be exclusively pressurized via the at least one second pressure chamber.

Abstract: A variable displacement reciprocating pump with pumping rate that is adjustable from zero to maximum stroke while the pump is running. Stroke is varied by changing relative position of pairs of eccentric inner and outer cams that drive the pump's plungers. The pump's input drive shaft drives two gear trains: a first gear train that turns the inner cams and a second gear train that turns the outer cams. These cams normally revolve together with no relative motion occurring between them. A rotary actuator is positioned in the first gear train to rotate the inner cams relative to the outer cams and thereby changes the pump's stroke. A computerized system of sensors and control valves allows the pump to be automatically controlled or limited to any one or combination of desired output flow, pressure and horsepower.

Abstract: A variable capacity vane pump has a plurality of vanes radially extendably installed in their respective slots that are arranged in a circumferential direction in a rotor, a cam ring rockably provided on a supporting surface in a pump body and forming a plurality of pump chambers at an inner circumference side of the cam ring in cooperation with the rotor and the vanes, and a seal member provided at an outer circumference side of the cam ring and defining a first hydraulic pressure chamber located at a side where a pump discharge amount increases and a second hydraulic pressure chamber located at a side where the pump discharge amount decreases in a space outside the outer circumference of the cam ring. A center of the cam ring is offset to an inlet port side from a center of a driving shaft.

Abstract: The present invention is a variable displacement pump system for delivering precisely controlled oil flow and pressure, including a variable displacement pump having an inlet passage, an outlet passage, a first chamber and a second chamber for controlling the displacement of the variable displacement pump. The present invention also includes a fluid control device for receiving fluid from the outlet passage, and selectively delivering fluid to the second chamber. Fluid is delivered from the inlet passage to the outlet passage from the variable displacement pump, and fluid is also delivered from the outlet passage to the first chamber and the fluid control device. When fluid pressure is greater in the first chamber relative to the second chamber, the displacement of the variable displacement pump will decrease, and when fluid pressure is greater in the second chamber relative to the first chamber, the displacement of the variable displacement pump will increase.

Abstract: A variable displacement pump includes: a pump section arranged to be driven by an internal combustion engine, and to discharge a lubricant introduced from an induction portion to a plurality of hydraulic chambers, through a discharge portion, by volume variations of the hydraulic chambers; a variable mechanism arranged to move a movable member by using the discharge pressure of the lubricant, and to vary volumes of the hydraulic chambers which are opened to the discharge portion; and an urging section arranged to urge the movable member in a direction to increase quantities of the volume variations of the hydraulic chambers, the urging section having a spring constant which increases as a movement distance of the movable member in a direction to decrease the quantities of the volume variations of the hydraulic chambers increases.

Abstract: A variable displacement engine oil vane pump includes a displacement control for controlling displacement of the pump. The control includes a cam ring in a housing pivotally connected to a wall of the housing by a pivot. The cam ring is internally engaged by slide vanes. A control chamber is defined by the cam ring and the housing wall. A control orifice provides for communication of control oil from a pressurized source to the control chamber. A vent chamber is generally opposite the control chamber and is defined by the cam ring and the housing wall. A dump chamber is defined by the cam ring and the housing wall and is generally disposed between the control chamber and the vent chamber. A dump orifice provides for communication between the control chamber and the dump chamber. A vent orifice provides for communication between the vent chamber and the dump chamber.

Abstract: A variable displacement reciprocating pump with pumping rate that is adjustable from zero to maximum stroke while the pump is running. Stroke is varied by changing relative position of pairs of eccentric inner and outer cams that drive the pump's plungers. The pump's input drive shaft drives two gear trains: a first gear train that turns the inner cams and a second gear train that turns the outer cams. These cams normally revolve together with no relative motion occurring between them. A rotary actuator is positioned in the first gear train to rotate the inner cams relative to the outer cams and thereby changes the pump's stroke. A computerized system of sensors and control valves allows the pump to be automatically controlled or limited to any one or combination of desired output flow, pressure and horsepower.

Abstract: A radial pump has a housing with a cylinder ring is pivotally mounted therein. The cylinder ring has a circular aperture within which a cam surface is formed. A cylinder block rotates within the cylinder ring aperture and has a plurality of radially extending cylinders each having port which selectively communicates with a fluid inlet and a fluid outlet as the cylinder block rotates. A plurality of pistons is slideably received within the cylinders and engages the cam surface. An actuator operably coupled to produce movement of the cylinder ring, which alters the spatial relationship between the cylinder ring and the cylinder block to vary the amount that the pistons move within the cylinders. The amount of movement of the pistons within the cylinders is directly related to the magnitude of fluid flow delivered by the pump and moving the cylinder ring thereby controls the fluid flow.

Abstract: A variable displacement pump includes a control valve formed with a high-pressure chamber for introducing therein high-pressure fluid on the upstream side of a metering orifice, a pressure chamber for introducing therein pressure fluid on the downstream side of the metering orifice, a low-pressure chamber arranged between the high-pressure and pressure chambers for introducing therein low-pressure fluid, and a communication passage for providing fluid communication between one of the high-pressure and low-pressure chambers and a first fluid-pressure chamber of the pump.

Abstract: A control system for a variable displacement pump. The control system is operably associated with an engine control unit for passively or actively controlling the output of the pump in response to signals from the engine control unit.

Abstract: Within a cam ring (8), a rotor having a plurality of vanes (27) is eccentrically disposed. A metering orifice (136) is provided halfway on a discharge passage (135) of pressure fluid discharged from the pump, and a control valve is activated due to a pressure difference between the upstream and downstream sides of the metering orifice (136). A fluid pressure of the first fluid pressure chamber (21) is controlled by activation of the control valve (123). The second fluid pressure chamber (22) is shut off from the control valve (123) to introduce a pressure on the suction side at any time. To return the cam ring (8) in a direction of expanding a pump chamber (11), an internal pressure of the cam ring (8) is applied in the return direction.

Abstract: The invention provides a volume control apparatus of a radial pump or motor which downsizes a hydraulic pump or motor, reduces a weight thereof and improves a freedom in arrangement, and a positioning apparatus. Accordingly, a servo piston (8) is operated following to a control valve (9), presses a cam ring (2) so as to position the cam ring at a position in correspondence to a volume control pressure, and regulates a volume.

Abstract: A pump including a pump chamber 18, formed in a pump body 11, between a cam ring 17 and a rotor 15. The cam ring is formed so as to move in a direction whereby the pump capacity of the pump chamber increases and decreases. First and second fluid pressure chambers 33 and 34 are formed at opposite sides of the cam ring 17. The pump has a spool that is axially moved by a difference in fluid pressure between upper and lower stream sides of a metering throttle 50 connected to a discharge side passage 27 of the pump chamber. The spool is part of a control valve 30 that controls fluid pressure in at least the first fluid pressure chamber. An electronic driving unit, for example, a solenoid 60, applies axial thrust to the spool of the control valve.

Abstract: A fuel injection pump having a cam drive and an injection adjuster piston, acting on the cam drive and serving the purpose of an injection onset adjustment. The injection adjuster piston on a face end encloses at least one pressure chamber that via a control valve is either made to communicate with a pressure source or a relief line or can be closed entirely. The control valve is actuated by an a proportional electromagnet. As a result, only a little adjusting medium is required, to obtain a high efficiency of the injection onset adjustment, and advantageously the injection adjuster piston is stressed only axially, and frictional forces on the circumference of the injection adjuster piston are thus avoided.

Abstract: An apparatus for moving fluid from a first location to a second location comprises a housing containing a pump body having a central passageway with a fluid inlet and first and second fluid outlets in communication with the passageway. A shuttle having first and second fluid chambers is movable within the passageway of the body between first and second positions. First, second, third, and fourth generally annular shaped fluid passageways provided in the shuttle permit selective fluid communication between the first and second fluid chambers of the shuttle and the inlet and outlet ports of the pump body. First and second inlet passageways provided in the shuttle permits selective fluid communication between the inlet of the pump body and the first and second fluid chambers of the shuttle. A piston is reciprocally movable within the shuttle chambers by a uniquely configured operating mechanism, such as a cam ring.

Abstract: An infinitely variable ring gear pump comprising a stationary casing, an internal rotor (3) in said casing rotatably supported and driven by means of a shaft (2) and an external rotor (4) likewise rotatably supported, meshing with the internal rotor (3), the difference in the number of teeth of the gear ring running set comprising the internal rotor (3) and the external rotor (4) being equal to unity, having a tooth shape in which a plurality of expanding and contracting displacement cells (7) each sealed off from the other materializes due to tooth tip contact and kidney-shaped low and high-pressure ports (8, 9) fixedly arranged laterally in the region of the displacement cells (7) being provided in the casing, the ports (8, 9) being separated from each other by webs (10, 11) and the angular position of the eccentric axis (eccentricity 17) of the ring gear running set (5) being variable relative to the casing.

Abstract: A rotational hydraulic transformer for boosting system pressure of a hydraulic system, which is continuous, compact and has little pulsation, comprises: a first volume increasing/decreasing mechanism Y1 for cyclically and continuously increasing/decreasing the volume of a plurality of first annularly arranged spaces 8, by shifting the phase of each, by means of employing relative positional change of two relative moving members 1 and 3; a second volume increasing/decreasing mechanism Y2 for cyclically and continuously increasing/decreasing the volume of a plurality of second annularly arranged spaces, by shifting the phase of each, the second volume increasing/decreasing mechanism Y2 sharing the two relative moving members 1 and 3, and performing the increasing/decreasing by means of employing relative positional change of the two relative moving members; a pair of first channels A01 and A02, wherein one channel is connected to said first spaces of which the volume is increasing while the other channel is con

Abstract: A hydraulic reciprocating piston machine having a housing, a rotatable cylinder-barrel having a series of cylinders and each cylinder containing a piston which is operatively connected to a reaction member. The reaction member being urged by the forces created from those pistons subject to the pressure phase of the working cycle toward and against an abutment-member. The reaction member is purposefully provided with a limited freedom for movement with the housing, and the action of the pistons forces in urging the reaction member towards the abutment-member provides for a substantial reduction in the normal vibration of the reaction member without binding between the adjacent bearing surfaces.

Abstract: An adjustable hydrostatic pump (10), in particular a piston pump, is proposed, whose cam ring (22) is adjustable via a hydromechanical adjusting assembly (35) and which has a device for active noise abatement. A pressure chamber (39) of a adjusting piston (37) acting upon the cam ring (22) is acted upon by pressure changes, via an additional control unit (47) parallel to the hydromechanical pressure controller (41), in such a way that the oscillating actions of power-train forces on the hydraulic fastening of the cam ring (22) are reduced, thus lessening the noise produced by the piston pump.

Abstract: An adjustable radial piston machine (pump or motor) is described whose drive mechanism (10) has a comparatively compact structure and an especially good mechanical efficiency. The drive mechanism (10) has a bearing ring (19) which is arranged concentric to a rotor (11) and which can be swung or pivoted about a symmetry axis (Q,H) different from its rotation axis for adjustment of the radial piston machine. An adjusting device (22) for pivoting the bearing ring extends axially parallel to the bearing ring (19) and acts on a facing surface of the bearing ring (19). Working pistons (13) guided in the cylinders in the rotor perform two motion cycles per revolution of the rotor, which are equal, but in opposite directions, over respective 180.degree. angular intervals. Cylinders (12) on opposite sides of the rotor are acted on by identical pressures so that the forces on the rotor are balanced and the rotor rotates largely free of friction.

Abstract: A cooperating rotor device having a first rotor supported for rotation about a first rotation axis (R1) and a second rotor supported for rotation about a second rotation axis (R2). A cylinder rotor (32), supporting a plurality of radially aligned cylinders (33) spaced apart and supported for collective rotation about one rotation axis (R1). Each cylinder (33) having a piston (39) slidable within. A piston rotor (61) has a number of piston rollers (64) corresponding to the number of cylinders (33), each radially supporting a piston (39), with each piston roller (64) independently rotatably supported and all piston rollers (64) collectively rotatable about the other rotation axis (R2). Members including the piston rollers (64), pistons (39), cylinders (33), and cylinder ports (34), all sharing a common plane of rotation about diametrically opposed non-rotating valve ports (74a) and (74b).

Abstract: A radial piston hydrostatic machine having an outer housing structure and defining an internal chamber, a drive-shaft supported in the housing and operatively connected to the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons bear on the track-ring, the track-ring eccentrically position within the internal chamber by means of fixed abutment means in the housing, the abutment means disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and thereby suppressing vibration emanating from the track-ring.

Abstract: An advance mechanism for a pump comprises a fluid operable piston arranged to have pressurized fluid applied to a first end thereof to adjust the axial position of the piston. The arrangement further comprises means for applying fluid under pressure to a part of the piston remote from the first end thereof in order to apply a torque to the piston. In one embodiment, the means for applying comprises a passage extending within the piston, the passage communicating with the first end of the piston such that high pressure fluid is received by the passage.

Abstract: In a hydraulic transaxle, a radial ball piston pump and motor combination receive input torque and translate it into output torque, the direction of which is determined by the position of a cam ring located in the transaxle housing. This cam ring is movable by means of a control shaft which is manually operated. The invention provides an extended control pin linking the control shaft to the cam ring and a channel formed in the transaxle housing. When the control shaft nears a neutral center position, the channel and its rounded edges provide a detented ramp into which the length of a portion of the control pin may be seated. A spring acting on the control shaft urges the control pin into the detented position.

Abstract: A radial piston hydrostatic machine having an outer housing structure comprising at least two housing elements connectable together along a parting-plane arranged perpendicular to the rotational axis of said drive-shaft to define an internal chamber, a drive-shaft supported in the housing to drive the cylinder-barrel, the cylinder-barrel having a number of radial cylinders, each cylinder containing a piston such that the pistons can bear on the track-ring, fixed abutment means in the housing and disposed radially adjacent the track-ring for resisting the action of the pistons on the track-ring and suppressing vibration emanating from the track-ring.

Abstract: A distributor fuel injection pump for internal combustion engines having at least one pump piston, which is guided in a cylinder bore and defines a pump work chamber therein and whose axial feed stroke motion is produced by a cam drive having at least one roller running on an annular cam race; at least one part of the cam drive is rotated to adjust the supply onset of the pump piston. This adjusting device is integrated into the housing which contains the cam drive by providing that the adjustable cam ring has radially protruding pressure vanes, each of which protrudes into a pressure chamber in the pump housing and divides this chamber into two pressure subchambers. Rotating the cam ring for the purpose of adjusting the supply onset of the pump piston over a wide angular range can now be effected by imposing pressure in alternation upon these pressure subchambers, which act in opposition upon the pressure vanes or the cam ring.

Abstract: A hydrostatic piston machine having a housing comprising two shells of a part-cylindrical form, the shells connectable together along a parting-plane in which the central axes of the drive-shaft and cylinder-barrel lie. Each housing element is provided with a number of semi-circular formations and recesses which form pockets or apertures when the housing shells are connected together to provide support surfaces for the working elements of the machine. A cylinder-barrel mounted within a chamber formed between the shells and is provided with a number of cylinders each containing a piston. Fluid-passageways are provided in the housing to receive and supply fluid to the pistons of the machine.

Abstract: A hydraulic drive system for a battery operated portable compression tool. The tool has an electric motor. The drive system has a self-regulating variable displacement pump with a rotatable conduit frame having radial conduits, pistons reciprocally located in the conduits, and a ring bearing surrounding the conduit frame in an eccentric adjustable location. Ends of the pistons are located against the inside of the ring bearing. A valve plate located against a front end of the rotatable conduit frame to control entry and exit of fluid into and out of the conduit frame as it is rotated.

Abstract: A hydrostatic pump and motor combination is disclosed including a rotor having radially disposed cylinders containing reciprocatably disposed spherical balls therein. A free outer race is eccentrically disposed about the rotor to define either a pump or motor. The cylinders are tilted relative to the center of the rotor to reduce side torque thrust loads on the cylinders. Also disclosed are a hydrostatic pump and motor including matching spherical slipper shoes and spherical free outer race. Hydrostatic thrust cups are disposed within the cylinders to reduce frictional losses, wear, and leakage. The thrust cups include hydrostatic means for supporting the balls in the cylinders, thereby self adjusting in response to fluid pressure and centrifugal loads.

Abstract: A fuel pumping apparatus has a fixed body in which is defined bores containing pumping plungers. The plungers are moved inwardly by cam lobes on a rotatable cam ring to displace fuel to an associated engine. The cam ring is provided with an annular extension within which is located a drive shaft. The drive shaft is coupled to the extension of the cam ring by means of a tongue and slot connection. The tongue is carried on a push member mounted in the drive shaft and movable by means of a piston and the tongue and slot are arranged so that as the piston moves, relative angular movement will take place between the drive shaft and cam ring.

Abstract: A neutral centering spring mechanism (71) is provided for a variable displacement hydrostatic pump (25) of the type of which control of the displacement occurs in response to rotation of a control shaft (101;101'). Disposed about the control shaft is a pair of preferably identical actuator members (111,113), each of which is in engagement with a pin (115) such that clockwise rotation of the control shaft rotates one actuator member (111) while counter-clockwise rotation of the control shaft rotates the other actuator member (113). Each actuator member defines a movable stop surface (131,137), which are in engagement with fixed stop surfaces (133,139). A single torsion spring member (121) surrounds the actuator members, biasing both actuator members toward the neutral position.

Abstract: The improved hydrodynamic variator of velocity comprises a pump (3) having radial pistons and a hydromotor (4) also having radial pistons. At least the pump is arranged with a variable eccentricity and there is provided a central body (56) the latter having frontal distributors (30 and 31) which are placed in communication with the radial cylindrical cavities respectively of the pump and the hydromotor by means of the openings of the conduits (32 and 33). By varying the eccentricity of the pump, the rate of flow of the liquid in the pump is varied, thus causing a variation in the number of turns of the hydromotor.

Abstract: A rotary hydraulic machine having particular utility as a fuel pump for aircraft turbine engines that combines the desirable features of vane-type and centrifugal-type machines of similar character--i.e., high pressure positive displacement at low speed combined with improved reliability, package size and weight. This is accomplished, in accordances with a presently preferred embodiment of the invention, by providing a combined vane- and centrifugal-type pump that is configured to function as a pressure-compensated single-lobe vane pump for engine starting, and as a centrifugal pump at normal operating speed.

Abstract: A vertical pump for transferring a dispersion of solids in a liquid comprising an upper chamber for receiving the dispersion; an intermediate chamber in fluid communication with the upper chamber and including an outlet nozzle for discharging the dispersion; and a lower chamber in fluid communication with the intermediate chamber and including an impeller for inducing a vortex in the intermediate chamber. The dispersion is discharged from the outlet nozzle without deleteriously affecting the solids of the dispersion thereby transferring the dispersion independently of direct contact with the impeller. Generally, the solids are a friable sorbent, such as active carbon, and this pump can be used in combination with a screening apparatus which separates the solids from another liquid prior to delivering the solids to the upper chamber of the pump for forming the dispersion therein.

Abstract: A rotary distributor fuel injection pump includes a rotary distributor member movable axially in a body part. The distributor member has a transverse bore in which is mounted a pumping plunger. At its outer end the plunger is engaged by a cam follower including a roller which is axially movable with the distributor member and which engages cam lobes formed on the internal surface of a cam ring to effect inward movement to the plunger. Outward movement of the plunger is effected by supplying fuel to the bore and the extent of outward movement of the plunger is limited by stop rings on the opposite sides of the cam ring. The stop rings are mounted in the body and define internal inclined surfaces which are engaged by end portions of the roller so that as the distributor member is moved axially the extent of outward movement of the plunger will be varied to control the amount of fuel supplied by the pump.

Abstract: A back pressure sensor comprising a flexible beam having a pivot end with a pivot pin and a drive connector end with a means for engaging a pump drive. A pump actuator is connected to the flexible beam at a position intermediate the ends and connects with a positive displacement pumping member. A sensor beam is attached to the flexible beam at a connecting point spaced from said pivot end. A first capacitor plate is mounted on the flexible beam at a point which is spaced from the connecting point. A second capacitor plate is mounted on the sensor beam in a position facing and spaced apart from the first capacitor plate at a distance therefrom which permits formation of a capacitance coupling therebetween.

Abstract: A control apparatus for a variable displacement pump includes a variable displacement pump having an inlet port and a discharge port driven by an external engine. A piston assembly is provided for varying the amount of displacement of the pump. The control apparatus further includes a switching valve for switching operational fluid which is to be applied to and operates the piston assembly, an additional pump a control pressure a magnitude of which is proportional to the rotational speed of the external engine, a balance piston for transducing the control pressure from the additional pump into a force and for applying the force to one end of the switching valve. A discharge line is provided connecting the discharge port of the variable displacement pump with an external load, and a pilot line is branched off from the discharge line into the switching valve for applying a pressure in the discharge line to the other end of the switching valve.

Abstract: The device of this invention has a variable capacity pump, a channel through which the discharged fluid from the pump passes toward an actuator, a variable choke located in the channel and pressure detecting means which detects the pressure difference on opposite sides of the variable choke. The pump varies its volume in relation with the pressure difference detected by the pressure detecting means. The opening area of the channel is varied by the variable choke in relation with the pressure of the fluid being supplied to the actuator, namely the pressure of the fluid flowing downstream of the variable choke. The device of this invention may also have an auxiliary variable choke located in the channel. The auxiliary variable choke can control the amount of fluid being supplied to the actuator in response to the operating condition of the actuator.

Abstract: As a rotary pump, which is typically provided on an automobile, is provided with two alternative sources of motive power, typically including a driving connection to the automotive engine, and driving connection to an electric motor. These driving connections may be unidirectionally clutched in such a manner as to cause the electric motor to drive the rotary pump only when the pump is to be driven but the automotive engine is not operating up to a predetermined speed. Typically, the rotary pump is of the eccentrically mounted rotor type having radially outwardly protruding spring-loaded pistons effectively in contact with a camming ring. A slider is shown provided between the housing and the ring for effectively varying the magnitude of eccentricity of the rotor and thus for effectively smoothly varying the capacity of the pump.

Abstract: A variable capacity radial piston pump is disclosed, in which the radially outer ends of the pistons are constrained by engagement with the radially inner surface of a cam ring assembly that includes a radially inner ring, a radially outer ring, and rollable bearings between the inner and outer rings. The cam ring is shiftably mounted in the pump housing so that its magnitude of eccentricity relative to the pump rotor can be varied in order to vary the magnitude of suction and compression forces generated in the working fluid in the rotor chambers associated with the respective pistons. Several mechanisms for affecting the cam ring/rotor eccentricity variation are shown and described.

Abstract: A variable displacement fluid pump comprises a rotor rotatably disposed within a housing, an eccentric ring movable close to and apart from the rotor to change a first eccentricity between a center of an inner periphery of the eccentric ring and a fixed center of rotation of the rotor so as to vary a displacement of the pump, and a plurality of pumping chambers each having a variable volume which changes sequentially to introduce thereinto fluid from an inlet port and to discharge therefrom fluid to a discharge port as the motor rotates. The rotor is so disposed that the fixed center of rotation of the rotor is spaced apart by a predetermined second eccentricity from a locus of the center of the inner periphery of the eccentric ring towards the discharge port.

Abstract: A fuel pumping apparatus for a compression ignition engine includes a fluid pressure operable piston for determining the timing of delivery of fuel. Fuel control means is provided which includes a lever operable to increase the idling speed of the engine when cold. The apparatus also includes a mechanism operable by said lever to achieve from the hot idling position retarding the timing of delivery for starting and advancing of the timing of delivery for cold idling. The mechanism includes a pair of members the one member being movable by said lever and the faces of the members having tang and slot connections in their presented faces and the other member and the end of the piston having further tang and slot connections. The slot of one of said tang and slot connections being of varying depth.

Abstract: The specification discloses a centrifugal pump in which radial thrust on the impeller shaft is reduced by employing a modified volute casing in which the casing flow area downstream from the cutwater to a point generally opposite the cutwater is significantly greater than would be the flow area of a true volute casing, the area at a point generally opposite the cutwater being significantly less than the flow area of a true volute casing and the area just upstream of the throat back towards the point opposite the cutwater being significantly greater than would be the flow area of a true volute casing.

Abstract: A primary recirculating pump for pressurized water or boiling water nuclear reactors has a spherical housing with a radially extending integral outlet, a rotary impeller which is insertable or removable through a sealable opening of the housing, and a composite inlet including an outer section which is integral with the housing and a discrete inner section which is insertable and removable through the opening and serves to convey to the impeller, and to preferably accelerate, the fluid which enters through the outer section. The inner section may resemble a bend or a funnel which diverges from the impeller toward the outer section, and the outer section may resemble a bend, a substantially straight pipe which extends tangentially of the housing, or a helical or semihelical conduit. The plane of the outer section is closely adjacent to or even coincides with the plane of the outlet, especially when the outer section is tangential to the housing or resembles a portion of or an entire helix.