Abstract: A latching device for a pump housing for production of a releasable latched connection between two housing parts has, on a first housing part, an elongate latching hook comprising a latching protrusion on the upper side and introduction chamfers on the upper side and on the underside. A latching opening is provided in the second housing part and comprises a latching tongue defining the latching opening outwardly, the latching protrusion abutting this latching tongue. An introduction web is arranged on the underside of the latching opening and comprises an introduction chamfer for the latching hook. Two securing tongues engage laterally in the latching opening and protrude via a free tongue end into the path of the latching hook when said latching hook is inserted into the latching opening. They prevent an undesired automatic release of the latched connection caused by movement of the latching hook in a downwards direction.

Abstract: motor housing for a cabin air compressor includes a central body portion having a center wall thickness and an internal cavity that is configured to receive an electric motor, a first end portion having a second internal cavity that is configured to receive a first end winding of the stator, and a second end portion having a third internal cavity configured to receive a second end winding of the stator. A ratio of a wall thickness of either of the first or the second end portions to the motor wall thickness is at least greater than 1.68 to 1.

Abstract: An impeller includes a top shroud, a bottom shroud, and a plurality of vanes extending from the top shroud to the bottom shroud. The top and bottom shrouds are generally planar, and a lower edge of each vane tapers from an outer edge of the bottom shroud to a transverse tip edge thereof.

Abstract: Embodiments of the invention provide a hydraulic isolator to split a volute of a pump into two compartments. The hydraulic isolator is positioned within the volute and includes an inlet positioned around a volute inlet channel of the pump, and an outlet positioned adjacent to an outlet channel of the pump. The hydraulic isolator also includes a toroidal portion to at least partially surround an impeller of the pump.

Abstract: Systems and devices for thermodynamically regulating portions of a dynamoelectric machine are disclosed. In one embodiment, a fan assembly element includes: an axially inner shroud segment configured to form a portion of an annular assembly about a rotor of a dynamoelectric machine, wherein the axially inner shroud segment includes a rotor hub interface configured to physically connect to a complementary portion of a rotor hub; a set of fan blades physically connected to and extending axially from a face of the axially inner shroud segment; and an axially outer shroud segment physically connected to the set of fan blades.

Abstract: A centrifugal impeller includes a cover, a base opposite the cover and a plurality of blades. The cover has an inlet. The plurality of blades surround the inlet and are arranged between and connect the cover and the base. Inlet edges of one end of the blades adjacent the center of the impeller define a cavity in communicate with the inlet. The dimension of the cavity gradually decreases along the direction from the cover towards the base.

Abstract: A mechanical coolant pump for an internal combustion engine includes a pump housing defining an outlet volute, a first outlet channel comprising a first valve opening, a second outlet channel comprising a second valve opening, an impeller pump wheel, and an outlet valve arrangement. The second outlet channel is separate from and fluidically parallel to the first outlet channel. The impeller pump wheel pumps a liquid into the outlet volute. The outlet valve arrangement is fluidically upstream of the first outlet channel and the second outlet channel. The outlet valve arrangement comprises an integral valve body which pivots between an open position and a closed position. The valve body comprises a first retaining section and a second retaining section. When the valve body is in the closed position, the first retaining section completely closes the first valve opening and the second retaining section only partially closes the second valve opening.

Abstract: A fan assembly includes a channel structure and a centrifugal fan. The channel structure includes a housing and at least a slit. The housing has an accommodating space and a flow channel adjacent to each other. The slit is extended along the flow channel. The flow channel is communicated with the outside of the housing via the slit. The centrifugal fan is disposed in the accommodating space. The centrifugal fan draws air along an axial direction and generates an airflow. The airflow flows into the flow channel along a radial direction, and flows out to the outside of the housing via the slit.

Abstract: Provided is a uni-axial multi-stage radial gas expander which has a high degree of reliability and which can sufficiently cope with the conditions of a high pressure and a high pressure ratio. Two or more radial gas expander sections (11A, 11B) formed of two-or-more-stage impeller vanes (14a to 14h) arranged between bearings (21a, 21b) on a rotor shaft (13) consisting of a single shaft are housed in a signal casing (10).

Abstract: A compressor for pressurizing a flow of air within an aircraft including an inlet providing the flow of air to the compressor. An outlet provides the flow of air, after pressurization by the compressor, to a chamber of the aircraft. A diffuser assembly is disposed between the inlet and the outlet. The diffuser assembly includes one or more vanes at least partially impeding the flow of air through the diffuser assembly. A backing plate is included having a surface adjacent to the one or more vanes. The surface includes a relief feature that enables air to bypass the one or more vanes. The relief feature has an axial depth of about 0.5% to 2.5% of a width of a flow path through the diffuser assembly or of about 0.5% to 5% of a thickness of a flange of the backing plate. A method of operating a compressor is also included.

Abstract: A water pump (30) includes an impeller chamber (32) formed in a housing (31), a swirl chamber (40) formed in the housing (31) to communicate with a coolant passage (8) and the impeller chamber (32), and an impeller (33) that is supported to be free to rotate in the impeller chamber (32) and rotates in conjunction with an engine (2) so as to take in a coolant and discharge the coolant into the coolant passage (8) via the swirl chamber (40). The swirl chamber (40) is formed to be divided into a first swirl chamber (41) that communicates with the coolant passage (8) at all times, and a second swirl chamber (42) and a third swirl chamber (43) respectively connected to the coolant passage (8) via thermostats (S1, S2) respectively having switch valves that can be opened and closed. The thermostats (S1, S2) are operated to open and close, thereby connecting and cutting off the swirl chambers (42, 43) and the coolant passage (8), in accordance with a temperature of the coolant.

Abstract: A volute of a centrifugal pump includes a proximate section. The proximate section includes: an outer peripheral portion having a tapered shape such that, within a range of a rotational trajectory of each of vanes provided on an impeller, the outer peripheral portion gradually spreads out in a direction axially away from the vane; and an inner peripheral portion having a tapered shape such that, within the range of the rotational trajectory of each of the vanes, the inner peripheral portion tapers in the direction axially away from the vane. The inner and outer peripheral portions are spaced apart from each other with a flat proximal opposed surface portion therebetween. The opposed surface portion is opposed to respective axial end surfaces of vanes of the impeller. The volute also includes a peripheral wall surrounding the peripheral surfaces of the vanes.

Abstract: A fan unit includes a fan case, a partition member and a centrifugal fan. The fan case has an inflow port and a blowout port. The fan case includes a unit connecting portion for connecting the heat exchange unit. The partition member partitions an inside of the fan case into an upstream side space and a downstream side space. The partition member has an opening for allowing the upstream side space and the downstream side space to communicate with each other. The centrifugal fan includes an impeller including a plurality of backward curved blades. The centrifugal fan is arranged such that the impeller is located in the downstream side space and sucks air in the upstream side space through the opening. The blowout port is located on an outer side in a radial direction of the impeller in the downstream side space.

Abstract: A compressor of a turbocharger including a compressor housing and a compressor impeller. The compressor housing includes: a compressor flow passage, a compressor air inlet, and a compressor air outlet. The compressor impeller includes an impeller feeding flow passage. The compressor impeller is disposed inside the compressor housing. The compressor flow passage is disposed inside the compressor housing. The compressor flow passage is connected to the compressor air inlet and the compressor air outlet. The impeller air feeding flow passage is connected to the compressor air inlet and the compressor flow passage.

Abstract: An apparatus for pumping or compressing a fluid, the apparatus comprising: a housing having a front wall, a rear wall and one or more side walls interconnecting the front and rear walls to define a fluid rotation chamber; at least one inlet located substantially centrally in the front wall; an impeller located at least partially within the at least one inlet such that at least a portion of the impeller extends outwardly beyond at least a portion of the front wall; and at least one outlet, wherein rotation of the impeller causes fluid entering the apparatus through the at least one inlet to rotate within the fluid rotation chamber prior to exiting the apparatus through the at least one outlet.

Abstract: A centrifugal fan includes a housing and an impeller. The housing includes a first surface and a flow channel wall. The first surface has a surrounding section and an air inlet section. The surrounding section encircles the air inlet section. The flow channel wall defines a flow chamber and an air outlet, and at least a sidewall of the flow channel wall has a tongue portion close to the air outlet. The impeller is rotatably connected within the flow chamber. The surrounding section plus the air inlet section is an area on the first surface, on which the impeller is projected, and the surrounding section has a convex structure.

Abstract: A centrifugal fan is provided. The centrifugal fan includes a housing, a driving device, and blades. The housing includes a circular base and at least two struts. Each of the struts physically connects the circular base and the remainder of the housing, and each of the struts includes two peripheral edges. The driving device is placed on the circular base. Each of the blades has an arc shape and the blades are located in the housing. The driving device rotates the blades. The two peripheral edges of each of the struts form orthogonal curves with the blades.

Abstract: A heat-dissipation fan including a base and an impeller disposed at the base, wherein the impeller includes a plurality of first blades, a plurality of second blades and a plurality of connection ribs. Each of the first blades and each of the second blades are arranged alternately. Each of the connection ribs comprises a first edge, a second edge and a third edge. The first edge is connected with the first blade, the second edge is connected with the second blade, the third edge is connected with the first edge and the second edge, and the third edge and the second blade are spaced apart to form a first vent. The first edge comprises a first length, the second edge comprises a second length, and the first length is larger than the second length.

Abstract: A casing of a centrifugal fan includes a suction port forming wall portion, an opposed wall portion opposed to the suction port forming wall portion, and a sidewall portion connecting the suction port forming wall portion and the opposed wall portion. A tongue portion is provided at the sidewall portion. The tongue portion projects into an air passage in the vicinity of a discharge port to form a narrowed air passage portion within the air passage. A leading end surface of the tongue portion is shaped such that the width of the leading end surface increases from the suction port forming wall portion, where the suction port is formed, to the opposed wall portion. The tongue portion is shaped such that the projecting length of the tongue portion into the air passage continuously decreases from the suction port forming wall portion to the opposed wall portion.

Abstract: An object is to provide an air intake duct structure for a centrifugal fluid machine, capable of swirling the fluid introduced into the impeller in the reverse direction to increase the pressure ratio when the flow rate is high and swirling the fluid in the forward direction to avoid a surging when the flow rate is low, as well as securing a wide operating range, without using mechanical means. The centrifugal fluid machine 1 includes an impeller 12 mounted to a rotation shaft and a housing 4 for housing the impeller 12. The air intake duct structure 10 is for directing a fluid “f” to a rotational center 12a of the impeller 12 housed in the housing 4 via an intake duct portion 4a of the housing 4 protruding in an axial direction of the rotation shaft, the fluid “f” flowing in a substantially orthogonal direction to a rotational axis line 3.

Abstract: A turbo machine (1) comprises a casing (2) and a first volute tongue (12), an impeller (3) with at least one vane (4), and a flow splitter plate (5) comprising a second volute tongue (13) for splitting a flow of a fluidic medium produced by the impeller. The flow splitter plate comprises at least one opening (10) connecting the first surface (8) and the second, opposite surface (9) so as to reduce or eliminate vibrations.

Abstract: A pump for immersion in a fluid reservoir has an extensible body, fluid conduit and drive in order that a length of the pump may be varied in order to accommodate a variety of reservoir fluid heights. In addition, the pump may be pivotable relative to at least a portion of a frame in order that the entrance angle may be adjusted. The pump has a bottom housing with a bottom inlet and at least two tangential fluid outlets that are upwardly angled towards the conduit. A combiner is provided to merge the outlets with the fluid conduit. An impeller within the housing is shaped to transfer fluid tangentially and upwardly within the housing to co-operate with the upward angle of the outlets. These features reduce fluid pressure loss and thereby increase fluid flow rate through the pump for a given input power.

Abstract: A centrifugal pump includes a motor having an output shaft, a volute mounted at one side of the motor and an impeller which is located inside the volute and attached to the output shaft. The volute has an inlet arranged along the axial direction, an oulet arranged along the lateral direction and a flow channel arranged along the circumferential direction. The flow channel has a spiral shape. The cross-sectional area of the flow channel increases towards the outlet.

Abstract: A volute shaped pump casing (1) for a centrifugal pump includes a chamber for housing at least one impeller (4) mounted on a shaft (2) for rotating the impeller around an axis of rotation (2a), a volute shaped chamber which forms a flow channel divided into a first volute (5.1) and a second volute (5.2), and a first channel (6.1) and a second channel (6.2) connected to the first and the second volute respectively. The first channel is also called long channel and the second channel is also called short channel. In the volute shaped pump casing (1), the first or long channel (6.1) is axially displaced with respect to the second or short channel (6.2) and/or with respect to the second volute (5.2).

Abstract: A turbocharger has a rotor housing. Said rotor housing has an insertion element. Said insertion element is configured such that the same forms an over-hanging spiral together with said rotor housing.

Abstract: A centrifugal fluid machine includes an impeller (4) that has a front shroud (41) arranged on one side in an axial direction, a rear shroud (42) arranged on the other side in the axial direction, and a plurality of blades (43) provided side by side in a circumferential direction between the front shroud and the rear shroud and is rotatably supported within a casing (2); a suction passage (2A) that allows a fluid to be sucked therethrough in the axial direction toward the impeller with the rotation of the impeller; a discharge passage (2B) that allows a fluid delivered under pressure by the impeller with the rotation of the impeller to be discharged in a direction intersecting the axial direction of the impeller; and a first flow path (5A) that communicates with the discharge passage, leads to the suction passage through a gap between the casing and the rear shroud, and an opening (5Aa) that opens toward the downstream side of the suction passage in a suction direction of a fluid.

Abstract: A rotary blood pump includes a casing defining a pumping chamber. The pumping chamber has a blood inlet and a tangential blood outlet. One or more motor stators are provided outside of the pumping chamber. A rotatable impeller is within the pumping chamber and is adapted to cause blood entering the pumping chamber to move to the blood outlet. The impeller has one or more magnetic regions. The impeller is radially constrained in rotation by magnetic coupling to one or more motor stators and is axially constrained in rotation by one or more hydrodynamic thrust bearing surfaces on the impeller.

Abstract: A centrifugal fan module, a heat dissipation device having the same and an electric device having the heat dissipation device are provided, in which the heat dissipation device includes a fin module and a centrifugal fan module including a volute-shaped frame and a centrifugal fan pivoted in the volute-shaped frame. The volute-shaped frame includes an air inlet, a larger air outlet and a smaller air outlet. The air inlet and the smaller air outlet are both on the same surface of the volute-shaped frame. The larger air outlet is coupled to the fin module. The smaller air outlet is arranged correspondingly to a maximum wind-speed flowing path of the centrifugal fan.

Abstract: A centrifugal pump includes an electric motor, an impeller driven by the motor and a pump housing having an impeller chamber, an inlet in communication with the impeller chamber via an opening, and first and second outlets in communication with the impeller chamber. The impeller chamber has an interference structure which forms first and second flow channels in communication with the first and second outlets. The interference structure directs the fluid in the impeller chamber to flow through the first outlet via the first flow channel when the impeller rotates in a first direction or to flow through the second outlet via the second flow channel when the impeller rotates in the opposite direction.

Abstract: A low-noise blower has an impeller with an impeller plate and a plurality of blades each attached to the impeller plate. Each blade has a tip and a leading surface with a first portion that is proximate to the tip and has a first radius that is within a range of 0.03-0.20 inch.

Abstract: A pump for a dishwasher has an impeller for conveying fluid, wherein it is formed as a centrifugal pump with the fluid to be conveyed being sucked-in in a central axial manner and flowing out in a radial manner. The impeller extends on a bottom surface above a pump base, wherein several fixed flow directing blades are arranged radially outside the impeller, said flow directing blades extending in a helicoidal manner with the pitch extending in the rotational direction of the impeller away from the pump base. At least one flow directing blade extends as far as up to the bottom surface of the impeller for picking up a circulating funnel or tube produced of fluid with air bubbles therein.

Abstract: A fan frame of a centrifugal fan comprises a housing and an inlet structure. The housing includes an opening. The inlet structure is disposed at the opening and includes a top portion and an edge portion. The top portion is disposed around the opening and includes a plurality of first chamfering angles, at least one of the chamfering angles is different from the others. The edge portion extends from the top portion to the inside of the housing through the opening and includes a plurality of second chamfering angles. A centrifugal fan including the fan frame is also disclosed.

Abstract: A liquid pump has a pump housing defining a pump chamber. A motor is accommodated within the pump housing and separated from the pump chamber by an end cap. An impeller disposed within the pump chamber is driven by the motor. The pump chamber has an inlet and one or more outlets. The outlets are located on a sidewall of the pump chamber and extend in a direction substantially tangential to an outer circumference of the pump chamber. Each outlet has a first end near the pump chamber, and a second end remote from the pump chamber. A cross-sectional area S1 of the first end is smaller than a cross-sectional area S2 of the second end, forming a diffuser within the outlet.

Abstract: A supersonic compressor provided may include an axial inlet and a centrifugal impeller fluidly coupled to the axial inlet. The centrifugal impeller may have a periphery and may be configured to impart energy to process fluid received via the axial inlet and discharge the process fluid from the periphery in at least a partially radial direction. The supersonic compressor may further include a static diffuser circumferentially disposed about the periphery of the centrifugal impeller and configured to receive the process fluid from the centrifugal impeller and convert the energy imparted. The static diffuser may include a plurality of diffuser vanes defining diffuser passageways therebetween. A supersonic ramp may be formed at an end of the at least one diffuser vane proximate the periphery of the centrifugal impeller. The supersonic ramp may be configured to generate a shock wave from the process fluid.

Abstract: A centrifugal compressor for compressing a fluid comprises a compressor wheel having a plurality of circumferentially spaced blades, and a compressor housing in which the compressor wheel is mounted. The compressor housing includes an inlet duct through which the fluid enters in an axial direction and is led by the inlet duct into the compressor wheel, and a wheel shroud located radially adjacent the tips of the blades. The wheel shroud has a port for bleeding off a portion of air flowing through the compressor. The bleed air enters an annular space, flows forward, and is injected back into the inlet flow through a plurality of circumferentially spaced slots defined through the wheel shroud. The slots are open at a leading edge of the wheel shroud.

Abstract: A centrifugal pump (20) for use with a portable fluid collection apparatus for collecting fluid produced by a person, the centrifugal pump comprising a substantially cylindrical pump chamber (26) having an inner diameter (D3), a fluid inlet (24) in fluid communication with said pump chamber, and a fluid outlet (28) in fluid communication with said pump chamber. The pump further comprises an impeller (10) having an outer diameter (D2) and being rotatably mounted on a driveshaft (22) within said pump chamber intermediate said fluid inlet and said fluid outlet, where said driveshaft is rotatable by driving means to rotate said impeller in use and accelerate fluid flowing into said pump chamber through said fluid inlet and out of said fluid outlet. The inner diameter of the pump chamber is substantially equal to or greater than 1.40 times the outer diameter of the impeller.

Abstract: The described embodiments relate generally to optimizing airflow in a computer system. By modifying the external surface of centrifugal cooling fan enclosures the pressure drop associated with airflow moving around the enclosures can be reduced. This is generally accomplished by rounding off hard edges from the outside of the cooling fan enclosure as well as forming cover surfaces rather than simply using flat cover surfaces. In some cases this can also involve modifying the shape of the fan inlet, or even contouring the shape of the cooling fan blades to allow air to flow more easily through the computer enclosure.

Abstract: A fan module includes a housing and at least one impeller. The housing includes first and second air channels. The housing further includes an axial air inlet in communication with the first air channel and a radial air inlet in communication with the second air channel. The housing further includes at least one radial air outlet in communication with the first and second air channels. The at least one impeller draws external air into the housing via the axial air inlet or the radial air inlet and expels air out of the housing via the at last one radial air outlet. By such an arrangement, external air can be guided into the fan module via different directions, providing an enhanced cooling effect.

Abstract: A centrifugal pump for delivering hot fluids, having a contacting shaft seal, a seal housing (13) for the shaft seal (14), and a return line (8) for a partial flow of the delivered fluid, in which no delivered fluid is discharged out of the seal housing (13); a separate housing cover (9) is disposed between the seal housing (13) and the pump housing (1); there is a contact surface which minimizes heat transfer between the seal housing (13) and the housing cover (9); and the return line (8) is connected to the housing cover (9) and/or to the pump housing (1).

Abstract: A turbo fan includes a main plate rotated by power provided from a fan motor, blades each having one end connected to the main plate to perform rotation movement, and a shroud having an inner circumferential part and an outer circumferential part, an other end of each of the blades connected to the shroud. The shroud includes a plurality of curved parts each having one side connected to the inner circumferential part and an other side connected to the outer circumferential part, the plurality of curved parts each having a predetermined curvature.

Abstract: A centrifugal fan includes a shell, an impeller, a tongue portion, and a protrusion. The shell includes a top plate, a bottom plate, and a sidewall connecting to the top plate and the bottom plate. The top plate, the bottom plate, and the sidewall define an air outlet. The impeller is disposed in the shell. The tongue portion is disposed in the shell and neighboring the air outlet. The protrusion is disposed on an inner wall of the shell and is physically connected to the top plate and the bottom plate.

Abstract: A method for assembling a ventilation system is provided. The method includes providing a ventilation hood that includes a cover portion and a discharge portion extending from the cover portion. The cover portion includes a first aperture, an opposite second aperture, and a cavity therein, wherein an interior of the discharge portion is in flow communication with the cover portion cavity. The method also includes coupling a rotatable member at least partially within the ventilation hood, such that the rotatable member extends at least partially through at least one of the first and second apertures, and such that rotation of the rotatable member induces a windage-driven flow of fluid between a portion of the rotatable member and at least one of the first and second apertures.

Abstract: A centrifugal pump including a rotor and a housing surrounding the rotor, the housing having a connection on the pressure side and another on the intake side, respectively. The housing surrounding the rotor is constructed as a composite part in which a first thin-walled layer (5) defines the inner configuration of the housing, and at least one second layer (11) provides structural stability to the housing.

Abstract: A fan and an electronic apparatus are disclosed. The fan comprises a housing and a blade wheel. The housing is shaped as a hollow column, a thickness of the housing is less than a preset thickness, a radial air inlet and an air outlet are disposed in a side of the housing, and the blade wheel is mounted in the housing and shaped as a cylinder. The housing is also provided with an axial air inlet disposed in at least one bottom surface of the housing so that air can enter the housing from the bottom surface by rotating the blade wheel. The heat dissipation performance of the fan is improved, the present invention solves the technical problem in the prior art that thinning of the fan in the super-thin electronic apparatus will lead to reduction in heat dissipation performance, and achieving technical effects that the electronic apparatus has high heat dissipation performance while super thinning the electronic apparatus.

Abstract: Disclosed herein is a cover module, including: a cover covering an impeller connected to a rotating shaft; a housing receiving a driving module coupled with the cover and including the rotating shaft; and a coupling member coupling the cover with the housing, wherein the cover is provided with a coupling part in an axial direction of the rotating shaft, the housing is provided with a coupling part corresponding to the coupling part of the cover in the axial direction of the rotating shaft, and the coupling member is fixed to the coupling part of the cover and the coupling part of the housing.

Abstract: A radial turbine includes a radial turbine wheel provided with a main pathway in which blade height progressively increases while curving toward an axial direction from a radial direction. A sub-let is formed on a shroud side of the radial turbine wheel at a position separated from the main inlet in the radial direction and the axial direction. Also, a blade shape that forms the sub-inlet is such that, in a plane orthogonal to the axial line of the radial turbine wheel, a center line of the blade is inclined at a predetermined angle toward the rotation direction with respect to the radial direction.

Abstract: A liquid pump (10) comprises an impeller (60) housed in an impeller chamber (22) having an axial inlet (26) and a plurality of centrifugal passages (23, 24) communicating with a plurality of outlets (35a, 35b) through a valve (80). The rotation of the impeller (60) pumps the liquid into one of the centrifugal passages (23, 24) and elastically deforms the valve (80) that controls through which outlet (35a, 35b) the liquid is pumped out of the pump (10).

Abstract: A turbocharger is provided herein. The turbocharger includes a housing and an adjustable core at least partially circumferentially surrounded by the housing, the adjustable core having a turbine rotor coupled to a compressor rotor via a shaft. The turbocharger further includes an adjustment mechanism coupled to the adjustable core configured to adjust an axial position of the housing relative to the adjustable core in response to adjustment commands.

Abstract: A multi-stage radial turbine for usage in energy capture from fluid streams with low to moderate relative speed.

Abstract: A pump casing for a centrifugal pump, which comprises an inlet opening, a discharge outlet, and a transition surface extending between an inner peripheral surface of the main pumping chamber and an inner peripheral surface of the discharge outlet, the transition surface arranged for separating an in use exit flow of material in the discharge outlet from an in use recirculation flow of material in the main pumping chamber. The transition surface has a cutwater having a profiled section which comprises a protrusion which extends irregularly from an otherwise generally rounded arched or U-shaped transition surface and is configured such that, in use, the velocity and/or turbulence resulting from the in use flow of the material being pumped in the main pumping chamber is reduced.