Abstract: A linear actuator system includes a linear actuator and at least one integrated pump assembly connected to the linear actuator to provide fluid to operate the linear actuator. The integrated pump assembly includes a pump with at least one fluid driver comprising a prime mover and a fluid displacement assembly to be driven by the prime mover such that fluid is transferred from a first port of the pump to a second port of the pump. The pump assembly also includes two valve assembles to isolate the pump from the system. The linear actuator system also includes a controller that establishes at least one of a speed and a torque of the at least one prime mover to exclusively adjust at least one of a flow and a pressure in the linear actuator system to an operational set point.

Abstract: A gear pump is capable of maintaining the pump volumetric efficiency for preferably supplying a hydraulic liquid while adequately securing a sealing area, even if a cross sectional area of a flow-in passage is increased. The cross section of a suction passage has a rectangular shape in a side close to a hollow space in a body, and has a circular shape in the outside of the body. The rectangular shape of the suction passage in the hollow space side in the body has a long side extending in a direction along the tooth width of the spur gears, and a short side extending along a direction perpendicular to the tooth width direction. The suction passage has a shape that smoothly connects the rectangular shape in the hollow space side in the body with the circular shape in the outside of the body.

Abstract: A pump includes a first housing part defining a first portion of a bore extending within the first housing part and shaped to receive a rotor; and a second housing part defining a second portion of the bore extending within the second housing part and shaped to receive the rotor. The first housing part has a first face abutable against an opposing second face of the second housing part to position the first portion of the bore with the second portion of the bore to receive the rotor. The first portion of the bore has a first circular cross-section portion centered along the first face and the second portion of the bore having a second circular cross-section portion centered, within the second housing part, at a distance from the second face.

Abstract: An axle assembly having a variable lubricant restrictor. The variable lubricant restrictor may be mounted to a differential carrier. Lubricant that is splashed by the differential assembly may move the variable lubricant restrictor from a first position to a second position to reduce lubricant flow through a divider wall opening.

Abstract: An air ejection port for ejecting air-mixed oil is structured with a first air ejection port provided on the inner peripheral side from an inscribed circle of an outer rotor and a second air ejection port provided on the outer peripheral side from a circumscribed circle of the inner rotor, the air ejection port can have an enlarged port area as the total of area of the first air ejection port and area of the second air ejection port in a state without being in communication with either of a suction port and a discharge port, and a disadvantage that a pump chamber of a previous stroke and a pump chamber of a subsequent stroke communicate with each other through the air ejection port can be avoided.

Abstract: An electricity generating device comprising a housing; a first lobed rotor and a second lobed rotor rotatably arranged in a fluid passage enclosed by the housing such that the lobes of the first and the second lobed rotor intermesh to create a barrier between a high-pressure and a low-pressure side of the housing during operation of the device; a first electricity generator to which the first lobed rotor is coupled, the first electricity generator being capable of varying the load of the first lobed rotor; and a second electricity generator to which the second lobed rotor is coupled, the second electricity generator being capable of varying the load of the second lobed rotor. There is also provided a method of synchronizing rotational positions of a first lobed rotor coupled to a first electricity generator and a second lobed rotor connected to a second electricity generator in a turbine.

Abstract: A pump device includes a shaft, a first gear pair, a second gear pair, a support pin, and a casing. The first gear pair includes a first driving gear which is disposed on the shaft and is rotatable together with the shaft, and a first driven gear driven by the first driving gear. The second gear pair includes a second driving gear which is disposed on the shaft coaxially with the first driving gear and is rotatable together with the shaft, and a second driven gear driven by the second driving gear and arranged coaxially with the first driven gear. The support pin penetrates the first driven gear and the second driven gear and rotatably supporting the first driven gear and the second driven gear. The casing covers the first gear pair and the second gear pair. The support pin is fitted to the casing to be fixed.

Abstract: A coating device, e.g., for painting motor vehicle bodies, comprises a sprayer for applying a coating material by means of an application element and an internal color-changer valve assembly, said assembly having several color inlets for selecting coating materials of different colors. The internal color-changer valve assembly is integrated into the sprayer and is connected by its outlet to the application element, in order to feed the selected coating material to the application element. Further, an external color-changer valve assembly has several color inlets for selecting coating materials of different colors, said external color-changer assembly having a separate structure from the sprayer and being connected by its outlet to the application element, in order to feed the selected coating material to the application element. An operating method corresponds to the device.

Abstract: A Roots-type blower may include first and second meshed, lobed rotors disposed in first and second chambers of a housing. Each lobe may have first and second axially facing end surfaces defining a twist angle that may be a function, at least partially, of the number of lobes on each rotor. A blower housing may include a bearing plate that may include one or more internal pressure relief ports. A pressure relief port may be configured to relieve fluid pressure from a trapping area that may form between first and second meshed rotors.

Abstract: The invention relates to a gear wheel pump with two meshing gear wheels which are rotatably mounted within a pump housing by means of a driven driveshaft and a crankshaft journal and which form a pumping channel system between a pump inlet and a pump outlet. Several gaps are formed between the pump housing, the gear wheels, the driveshaft, and the crankshaft journal. One of the gaps between the driveshaft and one of the gear wheels contains means for the rotationally fixed connection of the driveshaft to the gear wheel. In order to prevent leakages penetrating to the connecting means, according to the invention the gap between the driveshaft and the gear wheel is sealed, with respect to the front faces of the gear wheel, by means of a sealant.

Abstract: A Wankel engine with a peripheral wall of the stator body including a non-circular opening formed therethrough and defining at least part of a port. The opening has a perimeter defined by a first edge and remaining edges, with the remaining edges being located downstream of the first edge with respect to a direction of rotation of the rotor. The remaining edges extend non parallel to a longitudinal axis of the apex seals.

Abstract: In a gear pump according to the present invention, a wall surface portion of a casing (2) includes a drive side partition surface (41) on which tooth crests (11) of a drive gear (10) slide, a driven side partition surface (42) on which tooth crests (21) of a driven gear (20) slide, a suction side inner peripheral surface (43) that connects the drive side partition surface (41) and the driven side partition surface (42) on a suction chamber (3) side, and a discharge side inner peripheral surface (44) that connects the drive side partition surface (41) and the driven side partition surface (42) on a discharge chamber (4) side.

Abstract: A pump apparatus includes: a housing; a pump unit; a suction passage; a discharge passage member including a discharge hydraulic passage which is formed therein, and which is arranged to discharge the hydraulic fluid pressurized by the pump unit to an outside of the housing; a first discharge passage insertion hole which is formed in the pump unit, and into which the discharge passage member is inserted through an elastic member; a second discharge passage insertion hole which is formed in the housing, and into which the discharge passage member is inserted through an elastic member; and an axial position adjusting mechanism arranged to adjust an axial position of the discharge passage member within the first discharge passage insertion hole and the second discharge passage insertion hole.

Abstract: A high-performance oil pump for pumping oil in an internal combustion engine that eliminates or greatly reduces cavitation in the oil pump, thereby increasing the efficiency and performance of the oil pump. The present invention provides a housing having an inlet for receiving a supply of oil and an outlet for discharging the oil. At least two gears rotatably and matingly are disposed within the housing for pumping the oil from the inlet to the outlet. A pressure regulation circuit is disposed within the housing for balancing oil flow pressure between the inlet and the outlet by redirecting a portion of the oil from the outlet to the inlet when said oil flow pressure reaches a predetermined level at the outlet in order to reduce or eliminate cavitation of oil in the oil pump.

Abstract: Positive-displacement auxiliary pumping systems for use in pump apparatus of different configurations are disclosed. The positive-displacement auxiliary pumping systems are included in positive-displacement rotary pumps having a casing defining a pumping cavity, an inlet port connected to the pumping cavity, a discharge port connected to the pumping cavity, and a positive-displacement auxiliary pumping port connected to the pumping cavity. Pumping elements move within the pumping cavity of the casing and define a collapsing pocket that maintains fluid communication with the positive-displacement auxiliary pumping port after the collapsing pocket is no longer in fluid communication with the discharge port.

Abstract: A hydraulic device has an inlet side and an outlet side and includes two meshing cogwheels. Each cogwheel has external oblique teeth and is arranged between an inlet side and an outlet side. At least one control groove is provided on an end side of the cogwheels. The control groove periodically produces a pressure equalizing connection during the rotation of the cogwheels.

Abstract: A Roots vacuum pump stator is arranged to house a pair of intermeshing rotors, said stator being characterized in that it comprises a director or deflector arranged to direct solid material entrained in a gas pumped through the pump towards the outlet. In other words, the stator according to the present invention has a means for directing or deflecting powder or solid material entrained in a gas being pumped directly towards an outlet of the pump or out of the pump. The directing means can comprise a channel disposed between the arcuate surface and the outlet, said channel comprising a portion that engages the arcuate surface prior to the bottom-dead-centre position and which extends away from the rotor's axis of rotation towards the pump outlet.

Abstract: A pump assembly including a housing, a pump unit having a low pressure portion and a high pressure portion and accommodated in a pump unit receiving portion which is formed in the housing, a suction passage, a low pressure chamber communicated with the suction passage and the low pressure portion, and a discharge passage, wherein when the pump unit is accommodated in the pump unit receiving portion, the low pressure chamber is formed between the pump unit and a wall surface of the housing which defines the pump unit receiving portion, and the discharge passage is formed by a communication pipe which extends through the low pressure chamber and communicates the housing and the high pressure portion of the pump unit with each other.

Abstract: A gear compressor or supercharger for compressing compressible fluids such as air, having a pair of intermeshing helical lobed rotors. An aperture is provided on the bottom of the compressor, at a rear end thereof, which permits air from the rear interior of the compressor to be in communication with high pressure supply air which is discharged from such compressor proximate the front of such compressor, on the bottom underside portion thereof. The above modification improves the efficiency of the compressor, particularly at high revolutions.

Abstract: An air compressor includes a compression mechanism for compressing intake air and discharging the compressed air, and an intake chamber portion through which intake air is introduced into the compression mechanism. The intake chamber portion has an inlet of intake air and an outlet connected to the compression mechanism. The intake chamber portion is integrated with the compression mechanism. The intake chamber portion has therein a partition wall extending in the direction from the inlet toward the outlet to form plural flow passages in the intake chamber portion. The plural flow passages have different flow path lengths and connect between the inlet and the outlet.

Abstract: A supercharger is provided that includes a housing having a first end and a second end. The housing may at least partially define a chamber and may include at least one rotor disposed within the chamber. The supercharger includes an inlet port proximate the first end of the housing and an outlet port proximate the second end of the housing. The supercharger further includes a relief chamber in fluid communication with the chamber. In an embodiment, the relief chamber may extend in the axial direction and may have a depth in the axial direction that is equal to at least about 10% of the axial length of the rotor.

Abstract: A gear compressor or supercharger for compressing compressible fluids such as air, having a pair of intermeshing helical lobed rotors. A plenum or cavity is provided at a rear end of the gear compressor, situated rearwardly of said rotors and below an respective axis of rotation of each of said rotors, which spans at least a distance between said respective longitudinal axis of rotation of each of said rotors. In a preferred embodiment the plenum is in direct fluid communication with high pressure fluid which is discharged from said high pressure discharge port. The above modification improves the efficiency of the compressor, particularly at high revolutions.

Abstract: A Roots-type blower with helical cycloidal rotors features relief recesses in the chamber walls, isolated from the input and output ports. The relief recesses counter variation in leakback flow with angular position intrinsic to helical cycloidal rotors, attenuating a noise source.

Abstract: A gear box assembly as used in an inverted portal axle or transfer case includes a drive gear and at least one driven gear in meshing engagement with the drive gear at a contact point. A gear housing closely surrounds portions of an outer circumference of the drive and driven gears to form a baffle area. The gear housing includes an discharge orifice that is located near the contact point and a fluid gallery that extends from the discharge orifice to other locations within the gear housing. As the drive gear drives the driven gear, fluid is pumped into the discharge orifice and through the fluid gallery to fluid outlets positioned at desired locations to lubricate other gear box components. Radial inlets with elongated chamfers and stator vanes can be formed within the gear housing to draw air ingested during pumping away from the discharge orifice. Additionally, a bypass loop can be used to scavenge unwanted air ingested into meshing gear teeth.

Abstract: A pump assembly including a housing, a pump unit having a low pressure portion and a high pressure portion and accommodated in a pump unit receiving portion which is formed in the housing, a suction passage, a low pressure chamber communicated with the suction passage and the low pressure portion, and a discharge passage, wherein when the pump unit is accommodated in the pump unit receiving portion, the low pressure chamber is formed between the pump unit and a wall surface of the housing which defines the pump unit receiving portion, and the discharge passage is formed by a communication pipe which extends through the low pressure chamber and communicates the housing and the high pressure portion of the pump unit with each other.

Abstract: The invention is to reduce flutter and wear and improve the serviceability and wear life of tip seals for roots blower and screw type compressor superchargers where used for improved supercharger output and efficiency. As the seals travel over the outlet opening, the seals move outward in their slots, leading to flutter which may shorten their useful lives. As each seal reaches the center of the outlet opening, it is forced back into its groove by engaging a valley of the mating rotor with the likelihood of increased wear. The invention provides longitudinally spaced support bars extending laterally across the opening in the directions of rotation of the rotors. The support bars have inner surfaces machined with the associated rotor cavity bores and thus smoothly support the seals as they ride over the support surfaces. The support reduces the flexing of the seals and the resultant wear.

Abstract: An intake assembly, such as a supercharger assembly, is provided for an internal combustion engine. The intake assembly includes a housing having a wall defining an inlet passage through which intake air enters the intake assembly. A plurality of stiffening ribs is provided on the wall opposite the inlet passage and at least partially defines at least one cavity. A plate is mounted to the wall of the housing and further defines the at least one cavity. The wall defines at least one orifice configured to provide communication between the inlet passage and the at least one cavity. The at least one cavity and the at least one orifice cooperate to form at least one resonator. A method of forming the intake assembly having integral resonators is also provided.

Abstract: An inlet for a compressor having a housing defining a generally C-shaped inlet opening and a rotor cavity configured to contain first and second rotors is provided. The inlet includes an inlet duct defining an inlet opening and a generally C-shaped outlet opening. The inlet duct has an inner wall defining a cavity operable to communicate airflow between the inlet opening and the generally C-shaped outlet opening. The generally C-shaped outlet opening of the inlet duct is substantially similar to the shape of the generally C-shaped inlet opening of the housing. The inner wall includes a floor portion and a roof portion. At least a portion of the floor portion is contoured to impart a velocity component to the airflow complementary to the tangential velocity of each of the first and second rotors during rotation of the first and second rotors.

Abstract: A rotary pump has a housing composed of two intersecting cylinder sections and pump rotors therein. The rotors roll off on one another and against the interior wall of the housing in a sealing manner and have two approximately club-shaped sections that are connected to each other at their narrower ends via a waisting. The club-shaped section of one rotor engages into the waisting of the other rotor. The rotors create in each phase of the rotation movement an evenly increasing intake volume in front of the inlet port and an evenly decreasing discharge volume in front of the outlet port, provision is made that, in order to improve the pumping performance and increase the stability under load, the surface lines, which function as sealing lines are designed sine shaped.

Abstract: An external toothed wheel pump, comprising a delivery chamber comprising an inlet and an outlet for a fluid; a first feed wheel and a second feed wheel which can be rotationally driven for delivering the fluid and are in a toothed engagement with each other which separates the outlet from the inlet; and sealing surfaces which axially face the feed wheels and form axial sealing gaps with the feed wheels, wherein at least one of the sealing surfaces comprises a relieving pocket on a high-pressure side of the delivery chamber only and except for the relieving pocket, extends circumferentially up to at least the root circle and tip circle of the axially facing feed wheel.

Abstract: A pump comprises a driving rotor and a driven rotor that are positioned in a housing such that, as the driving rotor and the driven rotor rotate, the teeth of the driving rotor and the teeth of the driven rotor mesh to form a positive displacement seal. The teeth of the driving rotor and the driven rotor are configured such that seals between the inlet side and the discharge side of the pump are formed between only the leading surfaces of the teeth of the driving rotor and the trailing surfaces of the teeth of the driven rotor.

Abstract: In a Roots vacuum pump, an inlet port is located at a position n spaced by a positive displacement angle of 120° in one direction from a center of each rotational axis relative to an imaginary line m connecting rotor axes. An outlet port is located at a position o opposite to the inlet port relative to the line. An air feed port is formed at a position t on a casing wall obtained by returning by 90° from the position o to the inlet port side so that two closed spaces are defined by adjacent rotor lobes and a casing inner wall at both port sides immediately after air suction respectively. The casing has discharge grooves in an area of the inner wall so as to communicate with the outlet port. The area ranges from the position o to a position u obtained by returning by 45° from the position o to the inlet port side. The discharge grooves have a total volume ranging from 2% to 5% of a volume of one of the closed spaces.

Abstract: A gear•rear shaft containing main body of a bottomed type is penetrated with a bearing hole and a rear face of the gear•rear shaft containing main body is coupled with a closing plate to form an airtight seal from an outside environment. Shafts extended from two gears to a side of the rear face are set to be shorter than a length of the bearing hole in an axis core direction. Bushes are also set to a length that is the same as that of the shafts. The gear•rear shaft containing main body is formed with a recess portion at the rear face and the bearing hole is penetrated to open to the recess portion. The gear•rear shaft containing main body is bored to penetrate with a low pressure port communicating with a low pressure region in an axis core direction.

Abstract: A dual-inlet gear pump includes a drive gear and a driven gear. The invention utilizes the discovery that the drive gear will typically move a higher flow volume than does the driven gear, particularly when the fluid being moved is an air/oil mixture. The present invention takes advantage of this discovery to communicate a first higher expected flow source to the drive gear, and to separately communicate a second, relatively lower expected flow rate to the driven gear. A particular application is in a scavenging pump for a jet engine.

Abstract: In a screw type vacuum pump which includes a housing provided with a rotor chamber, a pair of screw rotors in mesh with each other rotably provided in the rotor chamber, a transfer chamber of gas formed between an inner wall of the housing and flutes of the aforesaid pair of screw rotors, and a suction port and an exhaust port communicated to the transfer chamber, the gas being sucked from the suction port into the transfer chamber and exhausted from the exhaust port, by providing the aforesaid exhaust port in a side face of the housing, it is possible to form a larger exhaust port, and a time until the port is blocked with deposits can be prolonged.

Abstract: An improved high pressure intermeshing gear pump that achieves high efficiency and a low cost by forming the pumping cavity such that no fillets exist at the corners permitting closed fits without utilizing bearing end plates. In addition an improved coupling between the gears and their supporting shafts is disclosed as is a simplified machining method that eliminates burrs that may be formed during the drilling operations.

Abstract: A novel bi-rotational pump adapted to pump fluid in either of two directions by reason of construction inclusive of passageways and an array of check valves and pilot pistons which cooperate in one direction and in another way in the other direction.

Abstract: A Roots supercharger has an extended cavity with 103 mm diameter rotors having chambers defined by interleaved helical lobes with equal angular face offsets exceeding 60 degrees from inlet to outlet end faces angled in directions opposite to directions of rotor rotation. The chambers have angular seal times of less than 67 degrees of rotation. A preferred embodiment has a displacement of 122 cu mm/revolution, rotor length of 208 mm, face offsets of 65.3 degrees and seal time of 58.6 degrees. The rotor lobe helix angle is essentially 0.314 deg/mm, equal to the helix angle of a prior art supercharger with rotors of common diameter, displacement of 112 cubic inch/revolution, rotor length of 191 mm, previously considered maximum, 60 degree face offset, previously considered optimum, and seal time of 67 degrees. Both flow volumes and efficiency of the new configuration are improved from the prior art wherein the 60 degree face offset was considered optimum.

Abstract: External gear pump, comprising: a casing (3a, 3b) with a gear chamber (4), comprising an inlet (5) for a fluid on a low pressure side and an outlet (6) on a high pressure side and comprising axial and radial sealing stays (7, 8); toothed wheels (1, 2) being in toothed mesh, wherein the external toothings of the wheels (1, 2) form delivery cells (10) for the fluid which are axially sealed off by the axial sealing stays (7) and radially sealed off by the radial sealing stays (8); and at least one pressure fluid supply (15, 16) through which pressure fluid may be supplied to the low pressure side, wherein the at least one pressure fluid supply (15, 16) opens on the low pressure side into a delivery cell (10) which is radially opposed by one of the radial sealing stays (8).

Abstract: A supercharger includes multiple back flow ports which are controlled by valves. The valves regulate the timing and area for back flow of pressurized outlet air into the rotor chambers. The back flow air tends to equalize air pressure in the chambers prior to their exhausting into the outlet and thereby reduces flow back noise. The multiple ports are opened selectively or sequentially to provide noise control with improved efficiency at varying speeds.

Abstract: A rotary blower (26) of the Roots type, used as an engine supercharger, comprising a housing (50,52) including a forward wall portion (52F) defining an inlet port (30) disposed toward the upper portion of the housing. Typically, the housing defines an outlet port (34) on the underside (54) of the blower. Disposed within the housing is a pair of meshed, lobed rotors (28,29), with one of the rotors being driven by an input shaft (62). The blower includes a pair of timing gears (58,60) disposed adjacent the rearward end (52R) of the housing. The housing includes an inlet duct (32) disposed above the input shaft (62) and extending forwardly and transversely (FIG. 2) from the housing, and having a duct opening (70) in open communication with the inlet port (30). The arrangement of the invention provides substantially improved air flow efficiency through the blower, which corresponds to improved horsepower output of the engine on which the rotary blower is being used.

Abstract: The pump for generating pressure or negative pressure comprises a pump chamber (32) which has a high-pressure port and a low-pressure port. Two rotors (28, 30) having at least two blades are fitted to two parallel shafts (20, 22) in the pump chamber (32) that are offset to each other, the shafts defining an axial direction. A drive (10) is arranged on an end face of the rotors (28, 30) and a housing cover (34) is arranged on the opposite side. The housing cover (34) is configured cup-shaped and the high-pressure port (42) as well as the low-pressure port (40) are integrated in the housing cover (34). The inner wall (44) of the housing cover (34) delimits the pump chamber (32) on an end face and has two axial openings (46, 48) one each adjoining by one channel (40, 42) which is integrated in the body of the housing cover (34). The axial opening (48) for the high-pressure port, in operation of the pump, is covered by one of the rotors (28, 30) for a time to enable inner compression of the delivered medium.

Abstract: A pump for a printing press includes a plunger within a cylinder to be rotatable and reciprocatable and having a cutaway portion at its distal end, and a constant-speed motor for rotating and reciprocating the plunger. The plunger and the output shaft of the motor are radially offset relative to each other and inclined with respect to each other. The output shaft of the motor is coupled to the plunger via a transmission mechanism which includes an arm and a connection member. The arm is connected to, for example, the plunger, and the connection member is connected to, for example, the output shaft of the motor. The arm and the connection member are connected with each other at an eccentric position in such a manner that the arm and the connection member can displace relative to each other in the radial direction and can change the intersecting angle therebetween.

Abstract: According to the invention, discharge noise from rotary vacuum machines having complementary profiles is attenuated by interposing between the discharge from the primary pump and the outlet to the atmosphere, a transfer device having independent cavities, e.g. cavities on a rotor rotated on a shaft, the cavities moving sequentially from the discharge to the outlet while simultaneously providing isolation between the discharge and the outlet. This achieves dynamic attenuation of the noise in a manner that is particularly simple and low cost, while also being very effective in suppressing discharge noise.

Abstract: A rotary displacement machine has a housing and at least two annular displacement gears arranged in the housing and supported rotatably on a stationary axle, receptively. The at least two annular displacement gears have external teeth for conveying a fluid. At least two supply channels are provided in the housing and have a supply mouth, respectively, opening toward the annular displacement gears for supplying a fluid to the annular displacement gears. The supply mouth is configured such that, upon operation of the rotary, displacement machine, a fluid exiting from the supply mouth reaches either only the teeth of a single one of the annular displacement gears or only the teeth of the annular displacement gears rotating in the same direction.

Abstract: The invention relates to the design of backflow orifices for a rotary compressor serving as a compressor for an engine. One example of such a rotary compressor is a roots blower. The fluid conveyed by two oppositely rotating rotors from an inlet to an outlet of the compressor flows back partially via the backflow orifices. The edges of the backflow orifices are at a varying height from an inner surface contour of the pump casing. The height variation contributes to a reduction in the noise generated by the compressor.

Abstract: A gear pump for the power steering of a motor vehicle is integrated into the housing of the drive unit and is surrounded by both the discharge space and the intake space, which extend over the entire length of the housing Ribs are provided in the discharge space for pulsation damping and for stabilization of the pressure field. A filter space is provided between the cover and a filter cap.

Abstract: A method for the metered discharge of a string of a viscous medium, in particular of an abrasive medium containing solid particles, via a nozzle, in which the quantity of the medium is discharged as a function of the speed of the nozzle and is increased or reduced as a function of the acceleration or deceleration of the nozzle.

Abstract: In order to simultaneously generate pressure and negative pressure with a single-stage pump, said pump has a pump chamber (18) that is formed in a housing and that is provided with a suction port, a pressure port and a charging port. There is a pair of rotors (30, 32) in the pump chamber (18) that has at least three blades and that rotates in opposite directions around parallel spaced axes and the rotors intermesh free of contact and, together with the peripheral wall of the pump chamber (18), they define cells (60, 62a, 62b, 64) that are separate from each other.

Abstract: A pump for moving a fluid has a housing with a internal chamber accommodating a pair of rotating pistons. Each piston has protrusions that register with pockets in the other piston in non-contact relation as the pistons rotate.