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: The multiblade impeller of the present invention comprises a main plate, a side plate having a suction port at a center thereof, and a large number of blades provided between the main plate and the side plate and extend in the radial direction in an arc form. The main plate and the side plate each have a large number of ridge portions, each extending in the radial direction in an arc form so as to coincide with the shape of the blade extending in the radial direction in an arc form. End portions of the blades are inserted in grooves formed inside the ridge portions of the main plate and the side plate and are fixed to the ridge portions by being bent.

Abstract: A centrifugal fan apparatus is disclosed in the present invention. The characteristics of the centrifugal fan apparatus lies in that the width of airflow channel defined between the rim of the impeller and the inner wall of the housing accommodating the impeller is uniform, and two airflow spaces defined between the axial cross section of the impeller and upper housing and lower housing respectively are not symmetry. Due to these two characteristics, the centrifugal fan apparatus is capable of making larger pressure difference to inducing higher flow rate and reducing noise while the centrifugal fan apparatus is operated. The present invention also provides a dust-collecting module that is formed by adopting the centrifugal fan apparatus with a designed dust-collecting casing, which is capable of being a sucker of a vacuum cleaner to collect dust of the surroundings for the purpose of environment cleaning.

Abstract: A housing includes a top portion and a wall portion. The wall portion is connected with the circumference of the top portion. The top portion has a plurality of protruding structures disposed around a central axis of the top portion for increasing the force-bearing area of top portion. The thicknesses of the protruding structures are substantially the same as that of the top portion. The housing can be applied to a fan or a motor, and the housing can serve as a base of the motor, or serve as a hub of an impeller of the fan.

Abstract: The impeller is preferably modified to use back swept, radial or forward swept blades to accommodate relatively low, medium and high lift, respectively applications for both centrifugal compressor and turbine rotor use.

Abstract: A heat dissipating device includes a motor, a rotary unit, and a housing for receiving the motor and the rotary unit. The rotary unit includes a hub mounted to the motor and blades extending from the hub. The housing defines a hot air inlet, a hot air outlet, a cold air inlet, and a cold air outlet. The housing includes a first partition and a second partition located close to outer ends of the blades. The two partitions divide the housing into a first channel coupling the hot air inlet and the hot air outlet, and a second channel coupling the cold air inlet and the cold air outlet. The two partitions have widths greater than a pitch of the blades to prevent air from mixing in the two channels. The two channels create a bi-directional blower that removes hot air from and provides cold air into a computer case.

Abstract: A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

Abstract: A fan includes an impeller and a motor. The impeller includes a hub and a plurality of blades. The hub has a top portion, a connection portion, and at least one airflow-guiding portion. The top portion is connected to the connection portion. The blades are disposed around the connection portion. The motor is disposed corresponding to the impeller and used to drive the impeller to rotate. The airflow-guiding portion is disposed between two adjacent blades.

Abstract: A fluid flow actuated drive means 10 includes a rotatably mounted impeller 12 which defines a set of circumferentially spaced outer chambers 14 which extend inwardly from openings 16 along a peripheral edge 18 of the impeller 12 and a set of inner chambers 20 which are arranged radially inwards the outer chambers 14, each outer chamber 14 being connected to a corresponding inner chamber 20 via a passage 22 to facilitate the forming of a Venturi between corresponding inner and outer chambers 20 and 14 respectively.

Abstract: A cooling fluid pump includes a casing having a cylindrical pump chamber inside and an outer surface, the pump chamber having an inner surface, an impeller mounted rotatably inside the pump chamber and having a number of pump vanes, the impeller further having an axial end, a fluid path defined around the impeller in the pump chamber so that a fluid flows through the fluid path upon rotation of the impeller, a discharge port formed in the casing for discharging the fluid inside the fluid path and a suction port formed in the casing for suctioning the fluid into the fluid path upon rotation of the impeller, a protrusion formed on a portion of the inner surface of the pump chamber opposed to the axial end of the impeller, thereby separating the fluid discharged from the discharge port and the fluid suctioned from the suction port as well as pressuring the fluid flowing in the fluid path, and a heat receiving portion formed on a part of the outer surface of the casing overlapping the protrusion.

Abstract: A centrifugal fan comprises an impeller, a motor which is connected and rotates the impeller and a housing which has an intake and an air blowing port for housing the impeller. The impeller has a plurality of blades arranged on a circumference. The intake opens opposed to the right end (in FIG. 1) of the impeller. The air blowing port opens opposed to a side of the impeller. A gap enlarged portion, in which the distance between the outer circumference of the impeller and the inner face of the housing starts to increase at a point where the distance between the outer circumferential of the impeller and the surface of a nose portion is smallest therein, the nose portion being a region of the vicinity of an edge portion of the air blowing port, the edge portion being the closest side to the outer circumference of the impeller.

Abstract: A two-way air pump includes a housing, an air flow controller, a check valve, and a valve actuator. The housing confines an air control chamber, and is formed with a valve hole, an air outlet and an air inlet. The air flow controller confines an air impeller chamber, is formed with a hole set, is mounted rotatably in the air control chamber, and is rotatable between inflating and deflating portions to control fluid communication among the valve hole, the air outlet, the air inlet and the air impeller chamber. The check valve is mounted in the valve hole, and is movable between control-enabled and control-disabled positions. The valve actuator is provided on the air flow controller, and drives the check valve to the control-disabled position when the air flow controller is rotated to the deflating position. An air impeller is mounted rotatably in the air impeller chamber.

Abstract: A centrifugal fan includes a scroll casing having an almost cylindrical shape. The casing consists of first and second casings. The first casing constitutes one base wall and a part of a side circumferential wall of a cylinder, and the second casing constitutes the other base wall and the remaining part of the side circumferential wall. An air inlet is formed on a center portion of the base wall of the first casing, and an exhaust port that is formed on the side circumferential wall. An impeller having many blades and a motor for driving the impeller are contained in the casing. A cylindrical partition that is formed on the inside of the base wall of the second casing over the entire circumference. The partition consists of a high partition formed in at least a region close to the exhaust port and a low partition formed in the other region.

Abstract: An impeller assembly has a hollow body, multiple main blades and multiple booster blades. The main blades are mounted around the body to define multiple flow channels between the main blades. The boosting blades are mounted around the body at the bottom edge and each is located at one of the flow channels. Each booster blade has a segment aligning with and overlapping a corresponding one of the main blades. In such an arrangement, the speed of airflow is increased and the heat-dissipating efficiency provided by the impeller assembly is enhanced.

Abstract: A machine designed as a centrifugal compressor is applied as an organic rankine cycle turbine by operating the machine in reverse. In order to accommodate the higher pressures when operating as a turbine, a suitable refrigerant is chosen such that the pressures and temperatures are maintained within established limits. Such an adaptation of existing, relatively inexpensive equipment to an application that may be otherwise uneconomical, allows for the convenient and economical use of energy that would be otherwise lost by waste heat to the atmosphere.

Abstract: The centrifugal impeller includes a plurality of blades (3), a plurality of fluid paths (P) for delivering a fluid from an impeller inlet (1) to an impeller outlet (2), and a shroud (4) and a hub (5) for forming the fluid paths (P). Each of the fluid paths (P) is formed between adjacent two of the blades (3). A curved line (L3) of the shroud (4) curves so as to project toward the hub (5) in a region from a blade inlet (A) to a predetermined position (C) of the blade (3), and the curved line (L3) curves so as to project toward the opposite side of the hub (5) in a region from the predetermined position (C) to a blade outlet (B).

Abstract: A kinetic pump has a tangential axially inner inlet means and a tangential discharge and with a rotor having vanes forming fluid channels to move fluid from inlet to discharge. The volute is eliminated or restricted only to the discharge port sector, and the vanes, hence fluid channels, are oriented so as to be tangent to the inlet port axial cylindrical fluid entry zone. The removal of the volute makes the pump to be positive displacement, since the fluid is contained within the chambers enclosed by vanes, except for when passing the discharge port. The tangential orientation of the vanes allows the fluid, driven by atmospheric pressure to enter the chambers and fill the chambers both by the NPSH and by centrifugal force.

Abstract: A turbomachinery apparatus. A turbine is provided with a retainer having a bore step element for turbine wheel retention, and with an aperture manifesting a tailored diameter less than the trim diameter of the turbine, thereby to permit customization of the turbine efficiency characteristic. Various configurations of turbine retainers, with tailored diameter apertures, are disclosed.

Abstract: A back-to-back double-flow bi-directional thrust-balanced micro-impeller for use in optimized compression cycles of small volumetric flow rates is provided. The back-to-back micro-impeller is a component of a compressor capable of generating a pressure head suitable for maintaining the flow rate needed for dissipating heat, such as produced by an electronic component. The back-to-back micro-impeller provides a fluid path on both sides of the micro-impeller, imparting an equal momentum (or velocity) to the fluid. The left and right compressor sections provide a balancing of forces generated by high-pressure fluid against the two sides of the micro-impeller. This reduces vibrational forces and provides a balancing force on the shaft which reduces the thrust on the shaft in a direction away from the gas flow path. Also, the approximately equally distributed mass about the rotation axis X, provides for a balanced impeller which is desirable when operated at high rotation speeds.

Abstract: In a centrifugal blower, a casing forms a scroll duct on the outer periphery of a centrifugal fan. The scroll duct includes a motor scroll duct wall extending from the periphery of a motor casing wall in a radial direction, a suction scroll duct wall extending from the periphery of a suction casing wall in an axial direction, and an outer peripheral wall smoothly connecting the motor scroll duct wall and the suction scroll duct wall. The scroll duct walls include curves having substantially arc-shaped cross-sections. A radius of curvature of the arc of the motor scroll duct wall is greater than that of the suction scroll duct wall. The scroll duct does not form a protrusion in the inside. The air discharged from the fan creates a secondary flow in a single course of a swirling flow in the scroll duct. Therefore, noise due to interference with the discharging flow and secondary flow reduces.

Abstract: The invention concerns an electric turbin (1) comprising a turbine rotor (4, 7), a turbine stator (2, 3), an electric motor member (5, 6) for driving the rotor (4, 7) in rotation relative to the stator (2, 3), and having the following features: the turbine stator (2, 3) comprises a stator body defining a compression chamber (12); the turbine rotor (4, 7) includes a plurality of blades (26, 27) integral with a shaft (4) mounted coaxially rotating in the body (2, 3) of the turbine stator; the electric motor member (5, 6) comprises a toroidal motor stator (6) housed in a motor housing (16, 23) of the turbine stator (2, 3), at the center of the toroidal compression chamber (12) and a motor rotor (5) mounted on the shaft (4) of the turbine rotor, axially opposite the motor stator (6).

Abstract: A centrifugal fan includes: a housing installed at both sides of a driving motor and having an air suction opening and an air discharge opening; an impeller installed inside the housing and discharging air sucked through the air suction opening through the air discharge opening while being rotated by the driving motor; a motor bracket coupled to one side of the housing and connecting the housing the driving motor; and a noise reducing unit for minimizing a noise of air discharged to the air discharge opening.

Abstract: An expansion turbine stage for compressed gases has a housing and a turbine rotor. The housing has flow guide channels for feeding the compressed gas to the turbine rotor. The turbine rotor, which is over-mounted and has centripetal flow through it, is followed by an out-flow diffuser enclosed by the housing, to delay the cold expanded gas. The out-flow diffuser is arranged in a holder bore in the housing, as a separate component. For thermal insulation of the housing relative to the cold expanded gas stream, the out-flow diffuser is made of a non-metallic material having a low heat conductivity.

Abstract: Turbochargers of this invention comprise a turbine housing and a turbine wheel rotatably disposed therein. A center housing is connected to the turbine housing, and a compressor housing is attached to the center housing. A compressor is rotatably disposed within the compressor housing, and comprises two impellers placed in back-to-back orientation. A movable member is disposed within the compressor housing to downstream of the compressor to control the flow of air within the compressor housing. The position of the movable member can be operated to control the amount of pressurized air that is produced by one of the compressor impellers to provide enhanced compressor operating efficiency throughout the operating range and mass flow requirements of the engine.

Abstract: A turbine engine that includes a housing having a circular cavity of an inlet and an outlet that provide fluid communication to and from the circular cavity. A rotor having a circular body and least one sealing fin extending from the circular body to the cavity wall of the circular cavity. A gas delivered into to the circular cavity causes the fin to move as it expands in the circular cavity. A sealing flap may also be incorporated into the system in order to ensure that gasses are directed against the fin. A valving system for use with the turbine is also disclosed.

Abstract: A cross-flow fan is operated in a suction mode, mainly in air-ducts with a large width, to provide a smooth flow of regulatable air. In accordance with the invention, a smooth flow suction separation device is suitable for the regulated suction to a large width of an amount of air containing a solid fraction, and is also suitable for the separation of the solid fraction on the inlet side. In certain forms of its construction, the flow of air is made to circulate. The smooth flowing suction separation device is equipped with a curved centrifugal separation device and a fraction outlet. A characteristic feature of the invention is that it has a cross-flow rotor, a housing constructed as a pneumatic duct, and a closed suction element attached to the internal edge of a centrifugal separation device.

Abstract: A centrifugal air blower includes a fan having a plurality of blades spaced circumferentially therearound for generating an air flow. The fan is disposed in a main case which defines a first discharge passage for the air to flow therethrough. An extended case defining therein a second discharge passage, which has a cross-sectional area progressively greater toward an outlet thereof, is combined with the main case. An air guide means having an arcuately shaped surface for guiding air extends from the first and second discharge passages, in the main case and the extended case toward an outlet of the second discharge passage.

Abstract: In a centrifugal pump (10) for liquids comprising an impeller casing (50) inside which a centrifugal impeller (40) is rotatably mounted including a hub (42) from which a plurality of curved blades (44) delimited by two curved edges (44a,44b) extend, from one of the curved edges (44a) of the curved blades (44) a tab (48) extends on the side of the concavity of the blades (44) and is folded in the opposite direction to the blade (44) with respect to a radial plane.

Abstract: A water pump for a spa or the like has a pump water inlet, a pump water outlet and an impeller driving water from said inlet to said outlet. The impeller provides the water axially introduced at the pump water inlet with a radial component which delivers the water to a large plenum chamber surrounding the impeller and which plenum chamber has an increasing cross sectional area as the water moves from the pump water inlet to a plenum chamber outlet thereby reducing backpressure in the water. The plenum chamber terminates with the plenum water outlet located closely to the impeller and a smooth transition area defines the area extending from the plenum chamber outlet to the pump water outlet. The water outlet preferably extends so that the water has a directional component which is generally parallel to the direction of the water entering the pump through the pump water inlet.

Abstract: A centrifugal compressor for high pressure (10) with improved efficiency, of the type comprising a rotor (12), an inner case (14), diffusers (16) and diaphragms (18), wherein the surfaces which are subjected to passage of the flow of gas have been subjected to burnishing working.

Abstract: A disc turbine inlet collects working fluid, introduces it into the rotor housing at a defined location and imparted at a defined injection angle with respect to the tangential motion of the discs in rotary motion. An injection angle within the optimum range delineated by this invention enables the working fluid to entrain stationary or slowly rotating discs into motion. The inlet design combines smooth sectional transitions and arcuate directional changes to minimize frictional losses. The inlet has a nozzle section which locates precisely into a receiving aperture of the turbine rotor housing.

Abstract: A compound vacuum pump comprising at least one turbo-molecular stage and downstream therefrom a multi-channel molecular drag stage, a first inlet through which fluid can pass through the turbo-molecular stage and the molecular drag stage towards a pump outlet, a second inlet through which fluid can enter the pump at a location between the turbo-molecular and the molecular drag stages to pass only through the molecular drag stage towards the pump outlet, in which one or more channels of the molecular drag stage are adapted to communicate directly with the second inlet whilst the remaining channel or channels communicate with the turbo-molecular stage.

Abstract: A blower apparatus includes a blower housing having at least one airflow channel. A flexible sheet having at least one flap is coupled to the blower housing such that the flap overlaps the channel to form a one-way valve. A plurality of flaps may be positioned over a plurality of channels to form a blower apparatus with a plurality of one-way valves. The flexible sheet may include mounting features such as holes to facilitate assembly. For example, in one embodiment, the flexible sheet is pressed onto a plurality of pegs residing on the blower housing such that the holes receive the pegs. In another embodiment, the flexible sheet is pressed onto a plurality of pegs residing on an exhaust cover that is subsequently attached to the blower housing.

Abstract: To obtain an air conditioning apparatus which provides a favorable atmosphere to the ear and saves energy even if the suction resistance of the impeller becomes high due to such as dust in the air conditioning apparatus. The air conditioning apparatus is provided with an impeller which is formed by a plurality of vanes and a ring for supporting the plurality of vanes, and includes a nozzle portion formed by a stabilizer and an air outlet, a cross flow fan formed by a guide wall, and a heat exchanger. The ratio H/&phgr;D2 of the outside diameter &phgr; D2 of the impeller to the height H of the air conditioning apparatus is 2.2 or above and 3.0 or below.

Abstract: In a motor-driven air pump, a bottom wall and a surrounding barrier wall cooperatively confine a receiving space in which an impeller is mounted. The barrier wall is provided with angularly displaced first and second internal ports that communicate fluidly with first and second chambers, respectively. A first external port is disposed upstream of and communicates with one of the first and second chambers. A second external port is disposed downstream of and communicates with the other one of the first and second chambers.

Abstract: A fan structure having horizontal convection is disclosed herein mainly comprising a casing and a centrifugal flow fan wheel. The casing includes an air inlet, an air outlet, and a horizontal channel directly connected therebetween. The centrifugal flow fan wheel is mounted in the horizontal channel and selectively aligned or misaligned with a center of the casing.

Abstract: A fan structure having horizontal convention includes a casing and a cross-flow type fan wheel. The casing includes an air inlet, an air outlet, and a horizontal channel directly connected therebetween. The cross-flow type fan wheel is mounted in the horizontal channel and selectively aligned or misaligned with a center of the casing.

Abstract: An air flow guide device for mounting on a heat dispensing fan includes a U-shaped frame and each of the three sides of the frame has a curve outer surface. A plate is connected between two distal ends of the frame and extends inclinedly from a top edge of the two distal ends of the frame, and a slot is defined between the two distal ends of the frame and the plate. Air flow smoothly flows over the curve smooth surfaces and is sucked by the fan. The plate prevents the exhausted air from being sucked by the fan.

Abstract: A blower apparatus includes a blower housing having at least one airflow channel. A flexible sheet having at least one flap is coupled to the blower housing such that the flap overlaps the channel to form a one-way valve. A plurality of flaps may be positioned over a plurality of channels to form a blower apparatus with a plurality of one-way valves. The flexible sheet may include mounting features such as holes to facilitate assembly. For example, in one embodiment, the flexible sheet is pressed onto a plurality of pegs residing on the blower housing such that the holes receive the pegs. In another embodiment, the flexible sheet is pressed onto a plurality of pegs residing on an exhaust cover that is subsequently attached to the blower housing.

Abstract: In an exhaust gas turbocharger for an internal combustion engine including an exhaust gas turbine and a compressor connected to the turbine so as to be operated thereby, the turbine includes a housing consisting of an inner and an outer shell formed from steel sheets and being arranged in spaced relationship so as to form therebetween an intermediate space.

Abstract: The present invention comprises a pump (10) having a casing (14) with at least one first hermetically sealed chamber (19) and at least one second chamber (17) adjacent to said first chamber, defining a passageway (18) for fluids and having an inlet (15) and an outlet (16) for the fluids. The stator (12) is provided in this first chamber (19). In addition, a rotor-turbine assembly (11) is induced by the stator (12) to drive a fluid from the inlet (15) to the outlet (16), the rotor and the turbine being integral and wholly located in the second chamber (17).

Abstract: A casing (30) for centrifugal compressors comprises a substantially cylindrical body (31) which is internally hollow and has its own central axis (32). The internal cavity of the casing (30) has an internal central axis (34) substantially coinciding with the axis of rotation of the machine and offset, in a vertical direction, with respect to the central axis (32) of the external surface of the cylindrical body (31) so that the casing (30) has an eccentric shape, having portions of different thickness, so as to create zones where the attachment point for the gas inlet counterflange (35) and outlet counterflange (36) can be formed. The invention also relates to a method for the manufacture of a casing (30) for centrifugal compressors.

Abstract: There is provided a magnetically levitated apparatus wherein an impeller has one side supported by an electromagnet and the other side supported and magnetically levitated by an attractive force created between a permanent magnet and a permanent magnet of a motor rotor rotated by a motor stator to rotate the impeller and a magnetic bearing sensor provides an output which is in turn rectified and thus shifted to have a gain adjusted and subsequently a notch filter removes a carrier wave frequency component used in the magnetic bearing sensor, to prevent a PID compensator from causing voltage saturation attributed to high frequency noise.

Abstract: A casing includes a C-shaped casing side pump groove along blades of an impeller. A casing cover also includes a casing cover side pump groove facing the casing side pump groove. The casing side pump groove and the casing cover side pump groove form a pump fluid passage. A gap is provided between an outer surface of the pump grooves and the impeller. Depth, and outer and inner diameters of a pump groove starts to gradually change from a fuel upstream side of a fuel outlet. The depth of the pump groove gradually decreases, the outer diameter of the pump groove gradually decreases to approach an outer diameter of the impeller, and the inner diameter of the pump groove gradually increases to approach the outer diameter of the impeller. The pump groove ends at a downstream side of the fuel outlet.

Abstract: A blower cover and an air conditioner using such blower. A rollable sheet is locked between two side plates by rollable connectors. A belt plate is secured between the side plates to lock the rollable sheet between the side plates. The belt plate also directs air from the blower. The blower cover can easily be assembled at a work site without welding or expert metal working. The blower cover is used in an air conditioner in which air is forced upwards from the blower and the air is directed into a heat exchange unit by one or more air deflectors. Another air deflector directs air coming out of the heat exchanger in an upwardly direction out of the air conditioner and this air deflector also directs any condensate downwards toward a drain system generally located below the heat air conditioner.

Abstract: A turbine comprises a housing having an inlet and an outlet, a stator mounted in the housing and including an arcuate stator blade projecting radially inward, and a turbine rotor having a central annular jet path accommodating therein said arcuate stator blade in communication with the inlet and the outlet. The turbine rotor comprises a pair of annular flywheel discs formed with pluralities of rotor blades facing each other in an axial direction. The arcuate stator blade has at least one deflection guide to direct the jet stream of working fluid toward the rotor blades in the central annular jet path.

Abstract: An impeller for a centrifugal pump is provided. It has an inlet side and an outlet side. Additionally, the impeller has a base, a plurality of guide elements extending from the base fluid flow channels, and a centrally disposed inlet opening. The fluid flow channels defined by the guide elements impart energy to the fluid during rotation of the impeller. The second member serves as a shroud and encloses the fluid flow channels. The centrally disposed inlet opening through the shroud admits fluid into the flow channels of the impeller to then be conducted outwardly upon rotation of the impeller.

Abstract: A pump comprises a housing having an inlet and an outlet. An impeller assembly mounted for rotation within the housing includes a first impeller piece having a first mating surface thereon and a second impeller piece having a second mating surface therein. The second mating surface of the second impeller piece includes at least one groove therein so that at least one flow channel is defined between the groove and the first mating surface of the first impeller piece. A drive system operatively associated with the impeller assembly rotates the impeller assembly within the housing.

Abstract: In an exhaust turbine for a turbocharger having a rotor rotatably supported in a turbine casing wherein the turbine casing has a spiral inlet with an annular space disposed directly around the rotor and an axial cavity extending from the annular space axially into the casing and slideably receiving a guide vane structure so as to be movable between a retracted position in the annular space and an extended position, in which the guide vane structure is disposed in the annular space, the guide vane structure has opposite outer and inner cover rings and the turbine casing has a recess opposite the axial cavity so that in the extended position of the guide vane structure its outer cover ring is fittingly received in the recess while the inner cover ring is disposed at the outer end of the axial cavity providing for a smooth inlet flow duct surface.

Abstract: A centrifugal compressor for a turbo-fan engine includes a shroud covering the edges of vanes of a compressor wheel mounted on an outer shaft with a clearance &agr; left therebetween. A vertical section of the shroud includes an upstream portion extending in an axial direction, and a downstream portion curved radially outwards and extending from a downstream end of the upstream portion. The thickness of the downstream portion is increased gradually from the upstream side toward the downstream side. Thus, it is possible to prevent the variation of the clearance &agr; defined along the downstream portion of the shroud which exerts a large influence on the compression performance, thereby suppressing the reduction in performance due to the thermal expansion of the shroud.