Abstract: A centrifugal fan includes a main shroud and a sub shroud. The main shroud is configured to connect upper ends of outer rims of a plurality of blades spaced apart from one another in a circumferential direction of a base. The sub shroud is provided at the upper end of the outer rim of each blade and serves to prevent air from moving from a pressure surface to a negative pressure surface of each blade by passing over an upper end of the blade.

Abstract: A gas turbine engine includes a radial compressor with first and second blades. The first and second blades have tuned leading edges that prevent natural frequencies from exciting at speeds within an expected operating speed range.

Abstract: An impeller includes a plurality of vanes formed around a hub, each of the plurality of vanes defines an offset between a leading edge and a trailing edge.

Abstract: A system for reducing compressor noise includes a rotor having a plurality of blades. The blades have a nominal geometry characterized by a blade parameter. At least some of the blades are mistuned, such that they differ from the nominal geometry by greater than a manufacturing tolerance in the blade parameter. The blades produce shock waves at a blade passing frequency, and the mistuned blades shift acoustic energy away from the blade passing frequency to multiple lower amplitude tones at other frequencies. The system is configurable to be deployed with an inlet silencer that preferentially absorbs acoustic energy at some of the shifted frequencies.

Abstract: A wheel of a turbine engine such as an airplane turbojet is disclosed. The wheel includes a disk having blades and at least one ring of a metal matrix composite material mounted on the disk in order to take up centrifugal forces during operation. The wheel further includes at least one annular flange formed by sections arranged end-to-end and each including a radially internal annular portion applied on a flank of the disk and a radially external portion coming into contact with the ring in order to ensure the axial holding of the latter on the disk, and a device for radially holding flange sections on the disk.

Abstract: Disclosed is a high speed type impeller, including: a body having a shaft coupling hole into which a rotation shaft of a motor is coupled, the outer circumference of the body being widened from the top to bottom end in the insertion direction of the rotation shaft to form a bent surface, a step portion shadowed in the radial direction being formed on the top end of the body; a plurality of blades installed on the bent surface of the body to be bent at a predetermined angle to the rotation shaft direction; and an upper reinforcing ring installed at the step portion of the body. Even through the impeller is made of a low cost material, the reinforcing ring reinforces the weak portion of the impeller to improve durability. Reliability of the impeller is attained with high economical efficiency.

Abstract: Compressor impellers, compressor sections, and methods of manufacturing compressor impellers and cooling the compressor impellers are provided. In an embodiment, and by way of example only, a compressor impeller includes a bore section and a rim section. The bore section comprises a first nickel-based alloy and includes an inner disk portion and a first plurality of blade portions extending therefrom. The rim section comprises a second nickel-based alloy and includes an outer disk portion and a second plurality of blade portions. The outer disk portion is bonded to the inner disk portion of the bore section, and the second plurality of blade portions is bonded to the first plurality of blade portions of the bore section.

Abstract: A blade front edge of a turbo fan has, between a main-plate-side blade front edge and a shroud-side blade front edge, a projecting blade front edge which distances away from a blade rear edge (located in a rotation direction A) as it furthers away from a main plate, which curves to a position away from a rotation center, and, in a range close to the main plate, a main-plate-side front-edge skirt portion which distances away from the blade rear edge and inclines away from the rotation center as it becomes closer to the main plate. On the other hand, a main-plate-side blade rear edge, which is a range close to the main, plate of the blade rear edge, is substantially perpendicular to the main plate and a shroud-side blade rear edge, which is a range close to a shroud, is inclined so as to gradually distance away from the blade front edge (behind in the rotation direction A) as it furthers away from the main plate.

Abstract: According to embodiments of the invention, an impeller includes a hub, and a plurality of radial blades for drawing the air inflow axially through the hub and delivering the drawn air radially towards the outside. A ring is attached to one or more tips of the plurality of radial blades to block a portion of the tip toward the inlet side of the impeller. The preferred blockage factor, which is the ratio of a height of the ring to a height of the tip, is approximately in a range between 30% and 40%. By blocking a portion of the tip toward the inlet side of the impeller, the low-momentum flow zone toward the inlet side of impeller is blocked, while the high-momentum flow zone toward the back side of impeller is enhanced. As such, the performance of the impeller is enhanced.

Abstract: A process for manufacturing a disk shaped component comprising fabricating a disk shaped component using a composite material having at least a first material and a second material, wherein the first material is disposed at and proximate to a center portion of the disk shaped component and the second material is disposed at and proximate to a rim of the disk shaped component, wherein the first material comprises a first coefficient of thermal expansion, a first stress value and a first oxidation resistance, and the second material comprises a second coefficient of thermal expansion, a second stress value and a second oxidation resistance, wherein the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion, the first stress value is greater than the second stress value and the first oxidation resistance is less than the second oxidation resistance.

Abstract: A housing includes a major component. The major component has a planar section. The planar section has an aperture constituting an inlet. The major component has a generally cylindrical peripheral section. A tangential extension is provided. The aperture constitutes an outlet. The housing also includes a minor component. The minor component has a planar section. The planar section has an aperture. The aperture constitutes an outlet. A tangential extension is adapted to overlie the major component for creating a chamber. A rotatable assembly includes an annular plate. The annular plate has an aperture. Spaced impeller segments are provided. A propeller is also provided. The propeller has an axial bore. Propeller blades are provided. Openings are provided between the blades. The bore is adapted to receive a drive shaft of a motor. In this manner the propeller and the annular plate and the impeller segments are rotated.

Abstract: A turbocharger system for an internal combustion engine includes at least one compressor wheel. The at least one compressor wheel of a single stage or multiple stage turbocharger system is formed, such as by pressure casting, from at least one of an aluminum metal matrix composite and an aluminum alloy containing up to 5 weight percent scandium.

Abstract: A food centrifugal pump formed by stamping and welding, comprising a pump casing and a cover mounted therein, an impeller, a shaft and a motor provided on the outer side of the casing, wherein the impeller is mounted on the shaft and driven to rotate by the motor; the pump casing is provided with an inlet pipe and an outlet pipe; the impeller have a structure of half-opened type and consists of blades, a hub and a back cover plate, the front end of the blade is close to the inner side of the axial plane of the pump casing, and there is an end face seal formed therebetween; the pump casing is formed by stamping a single metal plate, the outer side of the axial plane of which is provided with an inlet pipe bracket used to support the inlet pipe, the end of which is connected to the outer side of the pump casing, the other end of which is nestedly connected to the inlet pipe and fixed thereon.

Abstract: The disclosed solid waste pump is a chopper pump, and preferably a chopper pump having a small rated motor and a semi-open impeller design. Particularly, a chopper pump having an impeller, at least one pump-out vane, an end plate, and a back plate including at least one cutting rib is disclosed. The impeller includes a back shroud and cutting vanes sharpened on a first edge extending opposite the back shroud and fixed on a first surface of the back shroud. The at least one pump-out vane is preferably fixed to a second surface of the back shroud opposite the first surface, while the end plate includes a surface adjacent to and facing the first edge of the cutting vanes and at least one internal cutting rib fixed to the end plate surface for shearing operation in combination with the sharpened edge of the cutting vanes of the impeller.

Abstract: An industrial fan impeller that includes blades having an outer edge with a tapered portion and a level portion and method of manufacture are provided. The industrial fan impeller includes a front plate with a first diameter and a back plate with a second diameter larger than the first diameter of the front plate. Blades are attached to the front plate and the back plate. Individual blades have an outer edge with a tapered portion and a level portion. The blades are positioned between the front plate and the back plate such that the tapered portion of the outer edge of the individual blades tapers towards the front plate of the industrial fan impeller.

Abstract: A radial-flow turbine wheel for a gas turbine engine includes a Scallop Radius defined between an axis of rotation and the backface between each of the plurality of turbine blades, a Tip Radius defined between the axis of rotation and a tip of each of the plurality of turbine blades such that a Scallop Radius/Tip Radius defines a ratio less than 0.6. This enables a lower temperature scallop region which drives lower transient stresses and increases the Low Cycle Fatigue life of the turbine wheel.

Abstract: A fan includes an impeller and a housing. The housing includes a base portion and a sidewall portion disposed around and connected with the base portion. A plurality of first recesses are disposed at a connection between the base portion and the sidewall portion, and a rib is disposed between every two adjacent first recesses. The impeller includes a hub having a base portion and a wall portion disposed around and connected with the base portion, and a plurality of blades disposed on a circumference of an outer wall of the wall portion. A plurality of third recesses are disposed at a connection between the base portion of the hub and the wall portion, and a rib is disposed between every two adjacent third recesses. The recesses can prevent the impeller and the housing from the defects and shape deformation caused by injection molding during manufacturing processes, and enhance the structural strength.

Abstract: A process for manufacturing a disk shaped component comprising fabricating a disk shaped component using a composite material having at least a first material and a second material, wherein the first material is disposed at and proximate to a center portion of the disk shaped component and the second material is disposed at and proximate to a rim of the disk shaped component, wherein the first material comprises a first coefficient of thermal expansion, a first stress value and a first oxidation resistance, and the second material comprises a second coefficient of thermal expansion, a second stress value and a second oxidation resistance, wherein the first coefficient of thermal expansion is greater than the second coefficient of thermal expansion, the first stress value is greater than the second stress value and the first oxidation resistance is less than the second oxidation resistance.

Abstract: The present invention provides an impeller in which a metallic bush can be inserted correctly into a synthetic resin impeller main body manufactured by resin molding using a die, and a determination as to whether or not the impeller has been manufactured correctly can be made easily. The impeller comprises: a metallic bush comprising a circumferential boss portion having a substantially truncated cone-shaped throttle portion positioned on a front surface axial end side, a periaxial support boss portion positioned in an axial center, and a circumferential protruding portion positioned on a back surface axial end side; and an impeller main body made of synthetic resin and formed with a V-shaped bulging portion that bulges axially in the center of a front surface side of a disk-shaped vane portion fulcrum, in which a plurality of vanes are formed integrally on the periphery of the V-shaped bulging portion.

Abstract: An impeller plate of an impeller of a centrifugal pump, particularly a channel impeller pump, for pumping liquids with solid or gaseous admixtures, is provided with at least one wide vane that is displaced toward the impeller drive by a distance D so that the impeller chamber is enlarged by a rearward portion thereof. In addition, the impeller comprises at least one auxiliary vane having a center width at between 25%-75% of the width of the wide vane. This arrangement improves particularly the gas transporting ability of the pump.

Abstract: A pump impeller for a centrifugal pump. The impeller is defined by a shroud rotatable about an axis of rotation. At least two pump vanes extend axially from the shroud, each of the vanes configured as a blunted tear drop shape and having an inside wall and an outside wall, the leading edges of which are interconnected by a blunt wall. The trailing edges of the inside and outside walls merge together. A substantially constant width flow channel is defined between the blunted wall of one vane and a confronting surface defined by an inside wall of the other vane. The vanes are tapered in the axial directions by inclining the inside wall of each vane radially outwardly.

Abstract: The present invention relates to a Francis runner for a hydraulic machine that comprises a belt with a rotational symmetry about a central axis of the runner, a ceiling with a rotational symmetry about the axis, and a plurality of blades (21, 22) extending between the ceiling and the belt. The runner also includes at least two elements (41, 42, 43, 61, 62, 63) partially defining at least the belt and/or the ceiling while at least one edge (231, 232, 241, 242) of a blade (21, 22) is inserted between the two elements defining the belt and/or the ceiling.

Abstract: An impeller assembly including a rim plate defining a plurality of blades and the backplate defining a blade interlock structure for aligning and coupling the plates together. The rim plate defines a plurality of fluid-engaging blades. The interlock structure includes a plurality of tine-shaped interlocks extending from the backplate. The interlock structure also includes a plurality of channel sections engaging the blades. Each blade of the impeller may engage the interlock structure in a saddle manner. The backplate is defined by areas of reduced thickness allowing outer portions of the backplate to flex (rotate) toward further contact with the rim plate.

Abstract: The invention relates to a rotor of a flotation machine, particularly to a rotor, that is used for dispersing air to a slurry, and which rotor comprises alternating air ducts and slurry grooves and a collar fitted to the rotor for guiding the slurry flow into the interior of the rotor for avoiding undesired cross flow effect of the slurry flow. The rotor of the present invention efficiently prevents sanding effect and provides excellent dispersion of air into the slurry.

Abstract: A multiblade centrifugal blower includes a centrifugal fan including a hub rotated by a motor, and plural curved rectangular blades arranged at predetermined intervals in a circumferential direction of the hub forming a cylindrical basket with an opening on a front side of the hub, and a scroll casing including an air inlet and an air outlet, and houses the centrifugal fan inside to face the air inlet. A length from a rear end to an front end of an outer edge of the blade is shorter than a length from a rear end to an front end of an inner edge of the blade, and a bell mouth is configured such that distance between a tip part of the inner edge of the blade and an inner wall of the scroll casing is the minimum at an inner tip part P of the bell mouth of the air inlet.

Abstract: The invention relates to a shroud for rotating blades of a turbo machine, in particular a gas turbine. Said shroud (10) is arranged along the circumference of a row of several rotating blades (14, 50) disposed on a rotor (12) and has at least one separation gap (16, 16?, 16?) along the circumference. The separation gap (16, 16?, 16?) is serrated and has at least three damping gaps (20, 22, 24, 26, 28) that are located at a distance from one another and extend at an angle from the axis of rotation (18) of the rotor (12), and adjacent connection gaps (30, 32, 34, 36, 38, 40) which connect the damping gaps (20, 22, 24, 26, 28) or extend the same in the direction of the shroud edges (46, 48). When the rotor (12) rotates, the width of the damping gaps (20, 22, 24, 26, 28) is reduced to the point where the gap walls (42, 44) forming the damping gaps (20, 22, 24, 26, 28) rest against each other.

Abstract: In a centrifugal compressing apparatus, a height of a blade of an impeller is made to decrease gradually from a front edge thereof to a rear edge thereof, and a rate of change of the height of the blade is relatively large near the rear edge. The height of the blade can be made large at the rear edge side under the design restriction that an exit width of the rear edge of the blade is set to a predetermined design value. The ratio of the width of the clearance and the height of the blade is thereby made relatively large. As a result, the ratio of a flow path area occupied by a clearance flow to a flow path area occupied by a main flow is reduced. Since the pressure loss is thus made small, a drop in the efficiency can be prevented.

Abstract: A centrifugal fluid pump has an impeller having a hub with vanes that may be airfoil shaped and may be twisted along their lengths. A shroud having an inlet is connected to the vanes to define with the impeller flow chambers between the vanes, at least a portion of each flow chamber having a substantially constant flow area to increase pump efficiency. An entrance feature may also be provided to improve entrance flow into the impeller, further enhancing pump efficiency.

Abstract: A turbine wheel for a gas operated medical handpiece includes a plurality of blades which extend in radial direction from a hub and extend in axial direction from a side ring web of the turbine wheel, and the front side of which is substantially concavely curved about an approximately radially running first axis of curvature. In order to increase the drive power or to better exploit the drive power at least one blade has at least in an axial end region an inclination surface which is inclined in the axial direction towards the front side.

Abstract: In a turbine wheel of an exhaust gas turbine comprising a turbine wheel with a hub and a plurality of turbine wheel blades which are arranged on the turbine wheel hub and which extend axially between a turbine wheel inlet and a turbine wheel outlet, the turbine wheel blades are constructed in such a way that the ratio of the hub contour thickness to the external contour thickness of each turbine wheel blade follows a defined function.

Abstract: The impeller for a centrifugal pump includes a carrier disk and possibly a shroud. The blades of the impeller are identical, but are arranged in pairs such that impellers of different hydraulic characteristics are formed with blades of the same shape.

Abstract: A centrifugal fan includes a space in which the dimension between a shroud-facing wall and a shroud, from the outer peripheral side to the inner peripheral side of the shroud, is substantially uniform, wherein the shroud-facing wall includes a recess extending in the circumferential direction, the recess being disposed at the inner peripheral side of the outer peripheral end of the shroud-facing wall forming the space having the uniform dimension so that the recess forms a space larger than the other part.

Abstract: A turbine includes a stack of substantially parallel disks, the rotation of which causes rotation of a shaft. The disks are separated by peripheral spacers, each peripheral spacer having the shape of an airfoil. Each peripheral spacer defines a chord which is angled radially inward, towards the axis of rotation of the disk. The peripheral spacers are located only in the vicinity of the periphery of the disk. Air, or other fluid, entering the turbine engages the airfoil shaped peripheral spacers, and the flow of air generates lift, and associated drag, causing the energy of the fluid to be more efficiently converted into mechanical, and ultimately, electrical power. The turbine is especially useful in harnessing wind energy for the generation of electric power.

Abstract: A housing includes a major component. The major component has a planar section. The planar section has an aperture constituting an inlet. The major component has a generally cylindrical peripheral section. A tangential extension is provided. The aperture constitutes an outlet. The housing also includes a minor component. The minor component has a planar section. The planar section has an aperture. The aperture constitutes an outlet. A tangential extension is adapted to overlie the major component for creating a chamber. A rotatable assembly includes an annular plate. The annular plate has an aperture. Spaced impeller segments are provided. A propeller is also provided. The propeller has an axial bore. Propeller blades are provided. Openings are provided between the blades. The bore is adapted to receive a drive shaft of a motor. In this manner the propeller and the annular plate and the impeller segments are rotated.

Abstract: A Francis pump-turbine includes a runner provided with runner blades arranged around in a circumferential direction of a main shaft of the runner, each of the runner blades being supported by a band at a bottom side thereof in a blade height direction and supported by a crown at a head side in the blade height direction, in which the runner blade is formed, at a trailing edge thereof, with a curved portion expanding to the main shaft when the turbine is in operation, the curved portion has a maximum point with respect to a straight line connecting a crown-side trailing edge connecting end at which the trailing edge and the crown are connected and a band-side trailing edge connecting end at which the trailing edge and the band are connected, and an angle ? formed by a straight line connecting the maximum point and the crown-side trailing edge connecting end and a straight line connecting the maximum point and the band-side trailing edge connecting end is set to be within a range of ??150°.

Abstract: In a multi-blade fan for an air-cooled engine, by defining the inlet angle ?1 and the angle ??2 to make the sum thereof less than 80° (preferably defining ?1 as 32° and ??2 as 36°), the multi-blade fan achieves greater air volume than in the case where the sum is made 80° or greater, where ?1 is the angle between the relative velocity direction and the peripheral direction on the inlet side of the blades, ?2 is the angle between the relative velocity direction and the peripheral direction on the outlet side of the blades, and ??2 is the difference obtained by subtracting ?2 from 180°. The number of blades can therefore be reduced to realize lower noise level while still maintaining the same air volume as the prior art multi-blade fan.

Abstract: A venturi receives incoming material through an inlet tube and subjects the material to pulverization. The material, as it undergoes pulverization, is further subject to moisture extraction and drying. An airflow generator, coupled to the venturi, generates a high speed airflow to pull the material through the venturi and into an inlet aperture in the airflow generator. The airflow generator directs the received pulverized material to an outlet where the material may be subsequently separated from the air.

Abstract: A low noise centrifugal fan impeller has a multi cellular form of construction comprising a multiplicity of individual radial flow channels disposed in a circumferential and longitudinal array with respect to the axis of rotation. This increases the “blade passing frequency” as compared to a conventional impeller and since higher frequencies have lower energy for a given flow output the total amplitude of the noise generated can be reduced. Each channel extends from a respective channel inlet to a respective channel outlet which is offset from the respective inlet in the longitudinal direction of the impeller, and involves an increase in the internal dimension of the respective channel in the direction parallel to the axis of rotation, thus assisting deceleration and compression of the air or other medium being conveyed as it flows through the channels.

Abstract: An impeller rotatable in a direction of rotation in a centrifugal compressor including an intake ring. The impeller includes a back plate having a shaft portion and a plurality of blades. Each blade extends from the back plate and includes an inducer portion adapted to draw fluid into the impeller and including a leading edge and an exducer portion adapted to discharge the fluid from the impeller and including a trailing edge. A blade pressure side is defined between the leading edge, the trailing edge, the back plate, and a blade tip. The pressure side is convex from the back plate to the blade tip. A blade suction side opposite the pressure side is defined between the leading edge, the trailing edge, the back plate, and the blade tip. The suction side being concave from the back plate to the blade tip.

Abstract: An improved coaxial rotor assembly for a helicopter includes an upper rotor system having a multiple of upper rotor blades each having outer tips and mounted on and extending outwards from a central rotor shaft and a lower rotor system having a multiple of lower rotor blades each having outer tips and mounted on and extending outwards from the central rotor shaft with the upper rotor system spaced an axial distance from the lower rotor system on the central rotor shaft. A rotor blade support ring extends circumferentially around each of the upper and lower rotor systems which movably engages and supports the outer tips of the upper and lower rotor blades in spaced apart relation such that the upper and lower rotor systems rotate in opposite directions and the rotor blade support ring means prevents contact between the upper and lower rotor systems during operation thereof.

Abstract: Wheel (10) of a turbine engine such as an airplane turbojet, including a disk (12) having blades (14) and at least one ring of a metal matrix composite material (20, 22) mounted on the disk (12) in order to take up centrifugal forces during operation, the wheel further including at least one annular flange (28, 30) formed by sections arranged end-to-end and each including a radially internal annular portion applied on a flank (36, 38) of the disk (12) and a radially external portion coming into contact with the ring (20, 22) in order to ensure the axial holding of the latter on the disk (12), and means (32, 34, 40, 42) for radially holding flange sections on the disk.

Abstract: On a suction surface side of a blade in an impeller, a convex portion is formed to assume a curved line from a front edge portion to a throat portion substantially in the middle in a radial direction, and this convex portion is formed to be flat assuming a curved line from the throat portion toward a rear edge portion, whereby this convex portion is formed in a position where a relative inlet velocity of fluid into the impeller is Mach number Ma?1.

Abstract: A centrifugal pump may include plural pump stages, each comprising an impeller assembly, a stationary disc assembly and a diffuser assembly, all disposed about an impeller shaft that is driven by a motor. The impeller assembly may include upper and lower impeller shrouds having facing surfaces, and a plurality of impeller vanes extending between the surfaces of the shrouds to define a plurality of flow passages for liquid to flow outwardly from a central hub of the impeller assembly. To assist in pressure recovery of the pump, the distance between the surfaces of the impeller shrouds may increase as the radial distance from the central hub increases.

Abstract: An exemplary blade (220) for a turbine wheel includes an exducer portion with a trailing edge and an inducer portion with a leading edge wherein the inducer portion has a positive local blade angle at the leading edge with respect to the intended direction of rotation of the turbine wheel. An exemplary turbine wheel (200) includes a plurality of such exemplary blades. Various other exemplary turbine-related technologies are also disclosed.

Abstract: The present invention relates to a fan impeller structure, which includes a hub having a plurality of blades distributed around the periphery of the hub in a radial manner. The blade has a windward surface and a leeward surface; at least a flow-guiding section is disposed on the leeward surface and is preferably located near the end portion of the outer edge of the blade and is mounted in parallel to the radial direction of the fan impeller. Therefore, when air is sucked in from the top and bottom sides of the blade respectively, the heat-dissipation performance loss resulting from the mutual collision of the air flow is avoided due to the flow-dividing and flow-guiding effect of the flow-guiding section.

Abstract: In a centrifugal fan the diameter of the impeller is rendered less than 20 mm, yet by rotating it under rotational conditions in which the centrifugal force along the impeller periphery is 10,000 m/s2 or more, the static pressure that the fan generates is heightened. At the same time, rendering the vane spacing a predetermined width or less reduces noise. Configuring in this way produces a small-scale, high-static-pressure, low-noise fan for cooling electronic devices. Furthermore, by mounting the centrifugal fan on a heatsink having densely arranged heat-dissipating projections a small-scale, high-cooling-capacity, quiet cooling device is realized.

Abstract: A radial-flow turbine wheel is provided. The radial-flow turbine wheel includes a hub having an outer radius gradually increasing from a front end to a rear end, a rear periphery of the hub being radially extended in a plane generally perpendicular to a center axis, and a plurality of turbine blades formed around the hub at constant intervals. A plurality of slots is formed by inward cuts at the rear periphery of the hub between the turbine blades of the hub. The turbine wheel restrains creation and propagation of cracks due to thermal stress, as well as improving a turbine efficiency.

Abstract: A bracket/spacer design in a bladeless turbine, compressor or pump comprising of a hub for axial mounting and one or more arms connected to the hub. This bracket/spacer configuration contributes in part or completely to form one or more fluid flow chambers along with coinciding geometry of the neighboring disk or disks facilitating the entrance or exit of fluid for the purpose of extracting or infusing energy into or from the fluid. Furthermore, this invention includes a precise description of non-constant angular and axial geometry of the bracket/spacer arm or arms.

Abstract: In a centrifugal compressing apparatus, a height of a blade of an impeller is made to decrease gradually from a front edge thereof to a rear edge thereof, and a rate of change of the height of the blade is relatively large near the rear edge. The height of the blade can be made large at the rear edge side under the design restriction that an exit width of the rear edge of the blade is set to a predetermined design value. The ratio of the width of the clearance and the height of the blade is thereby made relatively large. As a result, the ratio of a flow path area occupied by a clearance flow to a flow path area occupied by a main flow is reduced. Since the pressure loss is thus made small, a drop in the efficiency can be prevented.

Abstract: The invention relates to a radial fan impeller (1), in particular for using in gas fans with a steep fan characteristic curve, with the following features: with a plurality of blades (2) distributed around the periphery; viewed in the radial direction, the blades (2) extend from an inner inlet region (4) to an outer discharge region (6); the blades (2) extend axially, i.e.