Abstract: A compressor nozzle device comprises a set of adjustable vanes which is interposed between two opposite wall members (3, 5), and a unison ring (7) for actuating said vanes (1). The unison ring (7) is arranged at a side of one of said wall members (3) opposite to the other side thereof facing the vanes (1).

Abstract: A nacelle assembly includes an inlet lip section and a cowl section positioned downstream of the inlet lip section. At least a portion of the cowl section is moveable to influence an effective boundary layer thickness of the nacelle assembly.

Abstract: A method for controlling blade tip clearance within a gas turbine engine includes the steps of providing a compressor having at least one first rotor assembly, each first rotor assembly having a plurality of blades with each blade having a blade tip, at least one first stator assembly disposed adjacent at least one first rotor assembly, and a shroud having at least one blade seal surface disposed radially outside of at least one first rotor assembly, wherein the blade tips in each of at least one first rotor assembly has a mating geometry with at least one of at least one blade seal surfaces, and a clearance distance extending between the blade tips and the blade seal surfaces; providing a turbine having at least one second rotor assembly, each second rotor assembly having a plurality of blades with each blade having a blade tip, at least one second stator assembly disposed adjacent at least one second rotor assembly, and the shroud having at least one blade seal surface disposed radially outside of at least

Abstract: A turbine engine variable stator vane includes a platform having a circumference adjoining opposing surfaces. A trunnion extends from one of the opposing surfaces. An airfoil is supported on the other of the opposing surfaces opposite the trunnion. The airfoil includes leading and trailing edges. An overhanging portion of the airfoil, which includes the trailing edge, extends beyond the circumference. A fillet joins the airfoil and the other opposing surface and extends along the other opposing surface in a lateral direction beyond the circumference toward the trailing edge. In one example, the fillet is provided about the entire perimeter of the airfoil. The airfoil includes pressure and suction sides. The circumference includes a relief cut extending from the suction side and adjoining a notch in the circumference to form an apex overlying the end surface.

Abstract: Expansion turbine having a variable nozzle mechanism comprises an adiabatic expansion device located in a vacuum container having a turbine impeller therein which rotates and drives the turbine impeller during adiabatic expansion of very low temperature gas, and varies the throat area of very low temperature gas introduced in the turbine impeller by driving a nozzle member disposed near the outside end of the adiabatic expansion device by a drive force from a driving member located outside the vacuum container; a plate member provided detachably in contact with the outside end of the body of the adiabatic expansion device, wherein the support side of the nozzle member is connected to and supported by the plate member, and the drive side of the nozzle member is connected to and supported by the driving member.

Abstract: A variable-vane assembly for a variable nozzle turbine comprises a nozzle ring supporting a plurality of vanes affixed to vane arms that are engaged in recesses in the inner edge of a unison ring. The unison ring is rotatable about the axis of the nozzle ring so as to pivot the vane arms, thereby pivoting the vanes in unison. A plurality of radial-axial guide pins for the unison ring are inserted into apertures in the nozzle ring and are rigidly affixed therein such that the radial-axial guide pins are non-rotatably secured to the nozzle ring with a guide portion of each radial-axial guide pin projecting axially from the face of the nozzle ring. Each guide portion defines a groove for receiving the inner edge of the unison ring such that the unison ring is restrained by the radial-axial guide pins against excessive movement in both radial and axial directions.

Abstract: Expansion turbine having a variable nozzle mechanism comprises an adiabatic expansion device located in a vacuum container having a turbine impeller threrein which rotates and drives the turbine impeller during adiabatic expansion of very low temperature gas, and varies the throat area of very low temperature gas introduced in the turbine impeller by driving a nozzle member disposed near the outside end of the adiabatic expansion device by a drive force from a driving member located outside the vacuum container; wherein the driving member comprises a cylindrical member disposed coaxially with the turbine impeller, and the nozzle member is provided on the extension of the body of the cylindrical member in the axial direction.

Abstract: There is provided a fan unit including a shutter capable of closing the shutter despite a change in installation direction of the fan unit, an electronic apparatus including such fan unit, a method of opening/closing the fan unit, and the shutter. In the fan unit with the shutter, the shutter is opened and closed in different directions according to the installation direction of the fan unit.

Abstract: Provided is a variable-throat exhaust turbocharger in which a nozzle assembly including a nozzle mount and nozzle vanes has a firm support structure without affection by a thermal deformation of a turbine casing and an external force exerted to the turbine casing, and a scroll portion is formed in a substantially opened configuration so that the nozzle assembly can be simply formed in order to reduce the number of mold cores for a scroll during casting of the turbine casing, thereby it is possible to enhance the productivity of the turbine casing.

Abstract: A method for the variation of at least one blade row of a fluid-flow machine, in which, in dependence of the actual operating point, in addition to an aerodynamic speed, at least one further quantity pertinent to the position of the operating point in the family of characteristics of the fluid-flow machine is employed for control.

Abstract: A straightener blade for a turbomachine, comprising a platform arranged at a radially external end of the blade and adapted to be engaged in a annular groove of a housing, and a threaded rod radially extending outwardly from the platform and adapted to pass through an orifice of the housing in order to receive a fixing nut, the upstream and downstream edges of the platform each comprising a protrusion extending in the plan of the platform in order to limit the rotation of the platform in the groove when the nut screwed on the threaded rod is tightened.

Abstract: A variable vane shroud for a gas turbine engine comprises a cylindrically shaped body, a hole arranged at a circumference of the body, and a counterbore arranged concentrically around the hole on a radially inward facing surface of the body. The hole is for receiving a trunnion from a variable vane and the counterbore is for receiving a hub from the variable vane. A liner is inserted into the hole and counterbore such that the trunnion and hub are provided with a contact surface. The invention also provides a method for repairing a damaged counterbore in a variable vane shroud. A liner having a shape corresponding to a layer of material removed from the shroud is inserted into the void left by removing damaged material such that the counterbore is restored to pre-damaged dimensions.

Abstract: A diffuser includes multiple vanes rotatable about pivot pins between multiple positions. A mounting plate supports a backing plate. The vanes are arranged between the backing plate and the shroud. The pivot pins are in a slip fit relationship with the backing plate, vanes and shroud and are threadingly received by bosses in the mounting plate. The mounting plate and pivot pin arrangement better enables the backing plate and shroud to remain parallel with one another during deflection of the backing plate and/or shroud. Structure, such as integral protrusions and/or bolts, extend from between the backing plate and shroud through apertures in the vanes to better contain the vanes in the event of a catastrophic failure.

Abstract: In an exhaust-gas turbine of an exhaust-gas turbo-charger including a turbine wheel which is rotatably supported in a housing and to which exhaust gas can be supplied via an inlet channel and discharged out of the exhaust-gas turbine via an outlet duct, wherein a guide vane structure and an axial slide which interacts with the latter, are disposed in the turbine inlet at the transition from the inlet channel to the turbine wheel, the guide vane structure is fixedly mounted with respect to the housing and the axial slide is arranged at the turbine outlet side and is movably supported on an outlet duct contour sleeve and provided with an axial opening for accommodating the guide vane structure, and the contour sleeve includes openings which conduct exhaust gas from the inlet channel directly to the outlet duct and which are arranged so that they are covered by the axial slide when the axial slide is moved out of its open position, the guide vane structure extending axially over the contour sleeve openings so as

Abstract: A high efficiency, low maintenance single stage or multi-stage centrifugal compressor assembly for large cooling installations. The assembly is highly efficient by virtue of a variable frequency drive (VFD) that drives a permanent magnet motor and matches compressor speed with compressor load, a direct drive impeller that eliminates gearing losses, and magnetic bearings that reduce frictional losses. The back-emf produced by the motor provides an intermediate power source for the magnetic bearings in the event of a loss of electrical power. A cooling system provides direct cooling of the rotor with gas refrigerant, and cooling of the stator with liquid refrigerant. Modular construction allows the compressor to be retrofit with upgrades. An inlet guide vane system operates without need for oil lubrication. The use of light metal castings and elimination of gearing reduces the weight to one-third or less of comparably powered conventional units.

Abstract: The present invention concerns the field of turbomachines, in particular the cooling of the ring sectors (1) of a turbine (8) of a turbomachine (9). It more specifically concerns a turbine ring sector (1) comprising: a wall (11) bounding an aerodynamic flowpath (5) in which gases flow from the upstream region (52) toward the downstream region (53), and a multiperforated plate (2), situated on the opposite side of the aerodynamic flowpath (5) with respect to the wall (11), said multiperforated plate (2) comprising a bottom (21, 121, 221, 321) and side walls (22, 23), the distance between the wall (11) of the ring sector (1) and the bottom (21, 121, 221, 321) of the multiperforated plate (2) defining a gap (7) which is progressive in an axial direction, from the upstream region (52) toward the downstream region (53). According to the invention, the value of the gap situated at the upstream region (52) is below the value of the gap situated at the downstream region (53).

Abstract: A stability control algorithm is provided for a centrifugal compressor. The stability control algorithm is used to control a variable geometry diffuser and a hot gas bypass valve (when provided) in response to the detection of compressor instabilities. The stability control algorithm can adjust the position of a diffuser ring in the variable geometry diffuser in response to the detection of a surge condition or a stall condition. In addition, the diffuser ring in the variable geometry diffuser can be adjusted to determine an optimal position of the diffuser ring. The stability control algorithm can also be used to open a hot gas bypass valve in response to the detection of continued surge conditions.

Abstract: An adjustable vane system is provided for use in a turbomachine, including a plurality of movable vanes that may be positioned to change the cross-sectional area of an exhaust flow passage and minimize the pressure of steam adjacent the exit after the last row of rotating turbine blades. Each of the vanes preferably includes an overlapping portion for overlapping a surface of an adjacent vane to minimize leakage of steam along the longitudinal extent of the vane. The exhaust flow passage is defined by inner and outer diffuser members where either of the inner or outer diffuser members may be formed of the movable vanes.

Abstract: An integrated system for tidal/wave flow electrical power generation. This bi-directional system utilizes the wave flow on the shores and the flow of various rivers and estuaries to generate electrical power through a venturi box which has mounted in it and comprises of the following components: a vane assembly with variable pitch vanes made from high impact blade material; a drive shaft assembly that connects the vane drive unit with the generator; a flow detection vane that determines velocity and direction thereby providing input to the flow detection controller and variable pitch computer and controller; a solid state voltage regulator; a mechanical fly wheel assist for the drive assembly during transition between flow direction; a grid cycle input device to match the power being generated with the grid. This system is capable of being coupled together both physically and electrically. The generator unit assembly is a field replaceable unit to ease installation and maintenance.

Abstract: A dishwasher includes a number of spray arms, a circulation pump with a pump housing, an impeller, a suction port, and a number of discharge ports on the pump housing. The discharge ports are associated with the spray arms. A water diverter is located on a delivery side of the pump and generates a flow leading from the suction port selectably to one or more of the discharge ports. The water diverter includes a blocking element having a number of diaphragm openings positionable to one or more outlet positions by a drive via a rotation of the blocking element in a circumferential direction.

Abstract: A blower (1) has a housing (10) to which a blower pipe (2) may be removably connected. An internal combustion engine located within the housing (10) drives a blower wheel. The blower wheel, in turn, generates an air flow (11) within the blower pipe. To reduce the exhaust gases and the fuel consumption during idle operation of the combustion engine, a reduction device (12, 22), located in the blower pipe downstream of the blower wheel reduces the clear cross section of flow during idle operation of the engine.

Abstract: A variable vane arm is disclosed having dual retention capability to ensure vanes of a gas turbine engine remain connected to the vane arm even under surge loads or when fastener preload, or the entire fastener, is lost. The variable vane arm further provides a surge slot to facilitate rotation of the vane even when the vane is operating under surge or otherwise excessively high pressure conditions.

Abstract: Improved actuation assemblies are used with variable geometry turbochargers comprising a plurality of movable aerodynamic vanes attached to a movable unison ring that is coupled to an actuator. The actuation assembly includes a crank arm that is attached at a first end to the actuator, and at a second end to the unison ring. A first gear member is attached to the crank arm second end and includes teeth. The unison ring includes a second gear member attached thereto that also comprises teeth. The teeth of the first and second gear members are cooperatively engaged with one another. The second gear member is movably attached to the unison ring to maintain predetermined distance between the first and second gear members during operation of the turbocharger and related thermal movement of the unison ring.

Abstract: A variable vane arrangement (36) for a compressor (26) of a gas turbine engine (10) comprises a plurality of circumferentially arranged vanes (38), a plurality of operating levers (64) and a control ring (66). Each vane (38) comprises a fixed upstream portion (40) secured to a casing (30) of the compressor (26) and a movable downstream portion (42) pivotally mounted to the casing (30). The movable portion (42) of each vane (38) is pivotally mounted about an axis (Y) at the upstream end (52) of the movable portion (42) adjacent the fixed portion (40) of the respective vane (38). The movable portion (42) of each vane (38) has a spindle (60) arranged to extend through a respective aperture (46) in the casing (30). Each aperture (46) in the casing (30) has an elongate shape in cross-section and each aperture (46) has a bush (120) arranged within the aperture (46) and around the spindle (60) to fill the elongate shaped aperture (46).

Abstract: A variable vane arrangement (36) for a compressor (26) of a gas turbine engine (10) comprises a plurality of circumferentially arranged vanes (38), a plurality of operating levers (64) and a control ring (66). Each vane (38) is pivotally mounted to a casing (30) of the compressor (26). Each operating lever (64) is pivotally mounted at a first end (68) to the control ring (66) and is mounted at second end (70) to a respective one of the vanes (38). The second end (70) of each operating lever (64) comprises a multi-sided aperture (72) and each vane (38) has a multi-sided spindle (60) which locates in the multi-sided aperture (72) of the respective operating lever (64). Each operating lever (64) has a drive member (74) located in the multi-sided aperture (72) and around the multi-sided spindle (60) of the respective vane (38). Each drive member (74) engages the respective multi-sided aperture (72) and the respective multi-sided spindle (60) to transmit drive from the operating lever (64) to the vane (38).

Abstract: A vaned diffuser for a centrifugal compressor has provision for selectively adjusting the pitch of the vanes in order to accommodate variable load conditions. Each of the vanes is rotatable about a pivot pin near its leading edge and is engaged with an actuation member near its trailing edge. The actuation members are attached to a common ring which can be selectively rotated to move to the vanes in unison. The ring is supported by rollers at its outer periphery and is positioned at the outer periphery of a diffuser wall such that there is no forward facing step projecting into the flow stream. A throat is defined between adjacent vanes, and the pivot pin for each vane is located downstream of the throat on the pressure side of the vane to reduce turbulence in the flow at the throat.

Abstract: An improved design for turbines increases efficiency while reducing potential for fish kill. In an embodiment of the present invention as relates to Kaplan turbines, the gap between stay vanes and their corresponding wicket gates is reduced or eliminated by provision of an extension to the trailing edge of the stay vane. In alternative embodiments, the extension may be added to the wicket gate or affixed to both in an arrangement that permits free movement of the wicket gate. To facilitate eliminating the gap altogether, the extension may be made of a pliable material or be fabricated in a telescoping or accordion arrangement to permit contact with opposing parts without damage thereto. By designing extensions using accepted hydraulic principles, a better fit of the stay vane to its associated wicket gate, and possibly to the turbines runners may be effected, further improving operational efficiency and possibly even extending maintenance intervals.

Abstract: The pivots (2) of the blades (1) comprise removable portions (16) located at their outer end and adjustable in height using a thread (17) or a similar means in order to adjust the distance between the head (9) of a lever (10) controlling the adjustment of the blade and the casing (4) or the collar (8) of a bearing (5); if the centring bushings (7) of the bearings (5 and 6) are worn, harmful tilting of pivots (2) will be limited by a stop for the head (9).

Abstract: A diffuser includes an opening along the diffuser wall for preventing or delaying boundary layer separation of the main flow. The opening may include a curved passageway having a curvature convex relative to the main flow for utilizing the Coanda effect. A gas turbine may include the diffuser with an opening and a centerbody with an opening, each for providing a secondary flow of fluid into the diffuser. The gas turbine may direct fluid from an upstream turbine stage to the opening. A steam turbine may include the diffuser and may situate the opening downstream the diffuser inlet but upstream the location of boundary separation.

Abstract: A high-pressure ratio turbocharger of this invention has a two-stage compressor section comprising a first-stage compressor impeller rotatably disposed in a first compressor housing, and a second-stage compressor impeller rotatably disposed in a second compressor housing. The first and second stage compressor impellers are attached to a common shaft, and are positioned within respective compressor housing in a direction facing away from one another. A portion of the second compressor housing is formed from a compressor backplate attached to a turbocharger center housing. A scroll seal is disposed between the first and second compressor housings, and is interposed between the impellers to separate outlet air flow between each respective first and second compressor chamber.

Abstract: An air pump having a housing with a blower therein and an outlet and a control box. The control box has two conduits respectively and oppositely defined in a side face of the box, and two magnetic valves movably received in the control box and each corresponding to one of the conduits so as to selectively seal the conduits. The magnetic valve comprises a coil with a hole defined in a side face of the coil, a plug which has one free end movably received in the hole, a spring compressibly mounted between the side face of the coil and the plug and a pad securely attached to the other free end of the plug to selectively seal the conduit.

Abstract: A variable geometry nozzle suitable for a radial turbine in a turbocharger for an internal combustion engine. The turbine inlet, turbine outlet or both include a vane assembly having a housing and an adjustable cartridge movable in the housing. Each cartridge has vanes having a plurality of vane sections. Each vane section provides a vane geometry different than the vane geometries of the other vane sections.

Abstract: An air pump having a housing with a blower therein and an outlet and a control box. The control box has two conduits respectively and oppositely defined in a side face of the box, and two magnetic valves movably received in the control box and each corresponding to one of the conduits so as to selectively seal the conduits. The magnetic valve comprises a coil with a hole defined in a side face of the coil, a plug which has one free end movably received in the hole, a spring compressibly mounted between the side face of the coil and the plug and a pad securely attached to the other free end of the plug to selectively seal the conduit.

Abstract: Two stages of relatively rotatable guide vanes (22,24) are arranged in tandem. Shroud portions (42,46) on the vanes overlap in loose engagement, until an associated gas turbine engine starts operating. Gas loads then act on the downstream vane stage (24) and move it in a downstream direction until the opposing flanks of radially opposing lands (44,48) on respective shrouds (42,46) engage, whereupon, gas leakage via the overlap onto the turbine casing (40) is at least substantially reduced.

Abstract: A variable geometry turbine, particularly for a supercharger turbocompressor of an internal combustion engine, comprising an outer housing forming a spiral inlet channel for an operating fluid, a rotor supported in a rotary manner in the housing, and an annular vaned nozzle of variable geometry interposed radially between the channel and the rotor and comprising a control member moving axially in order to control of the flow of the operating fluid from the channel to the rotor, the control member being formed as an annular piston of a fluid actuator actuated directly by means of a control pressure.

Abstract: A turbine, intended to be used in a plant of the geothermal type, comprises an apparatus for the choking of the control stage. The latter provides closure means for closing at least one nozzle of the first stage of the turbine, the said nozzles facing a final section of a feed pipe of the said turbine. Also provided are control means for controlling the said closure means, capable of causing the said closure means to assume at least one position of rest and one working position in which they are disposed to close the at least one nozzle in the vicinity of the final section of the said feed pipe.

Abstract: An annular diffuser has its inlet located at the exit of a last row of blades of a gas turbine having initially very slowly increasing cross-sectional area with distance to accommodate the diffusion produced by the decaying wakes in the diffuser so as to prevent flow separation from diffuser walls and as a result to foster the diffusion process and to increase the efficiency of the gas turbine. The rate of increase of cross-sectional area, which is much smaller than that appropriate in diffusers having uniform flow at their inlets, allows wakes which form near the trailing edges of the last turbine blades to dissipate while avoiding flow separation. In the diffuser of this invention, at a distance from inlet of one half of diffuser height at inlet, the cross-sectional area increase is smaller than 6.5% of the inlet cross-sectional area. This is equivalent to the corresponding two-dimensional straight-wall diffuser angle of, approximately 3.7 degrees.

Abstract: A gas turbine with axially mutually displaceable guide parts that compensates for differing amounts of thermal expansion, comprising guide parts which can be displaced with respect to one another in the axial direction and enclose a funnel-like gas duct from outside. In order to optimize a rotor blade tip gap, the invention proposes to displace at least one of the funnel-like guide parts under control by means of a motor. As a result of the axial displacement, because of the funnel-like shape of the guide parts, the width of the rotor blade tip gap is changed.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.

Abstract: A variable inlet guide vane includes opposite pressure and suction sides extending along a chord between leading and trailing edges and in span from root to tip. The vane has a maximum thickness greater than about eight percent chord length and located less than about thirty-five percent chord length from the leading edge.

Abstract: An intake and exhaust damper assembly has a motor and fan assembly pivotally mounted for movement toward and away from a louvered rotatable blade damper.

Abstract: A vane having a trunnion portion and an airfoil portion is provided with a stress reducing undercut on the trunnion portion proximate to the transition zone defined between the trunnion portion and the airfoil portion of the vane.

Abstract: A method of coating a substrate includes the step of forming a chrome layer on the substrate by using a magnetron sputtering device, and the step of forming a chrome nitride layer on the chrome layer by using an arc type ion plating device while maintaining the temperature of the substrate between 100 and 200° C. A vane used for a vane-type compressor, which is subjected to a surface treatment according to the coating method of the present invention is also provided.

Abstract: The present invention is a fan with adjustable vanes for controlling the width of the wind generated by the fan. The vanes are adjustable to any angle. Preferably, the vanes are set at 10° with the generated wind for a narrow, focused beam, and to 45° with the generated wind for a diffuse, flood beam. The vanes are adjustable from a dial located on the outside of the fan housing. A motor drives the fan. The motor is controlled by a rotating dial on the outside of the fan housing. The rotating dial allows for adjusting the motor speed from 0 to 100%. Pressing a “burst” button located on the outside of the fan housing instantly provides 100% motor speed. The fan motor runs at full speed for as long as the “burst” button is depressed. A mounting yoke is pivotally connected to opposite sides of the fan housing, allowing the fan to be set at various angles.

Abstract: A wind power unit, that uses the power of wind, is made as a support installed power-generating unit comprising at least one turbine with a nozzle apparatus mechanically connected to a generator, a central shell, an annular front shell having at least one input channel of the turbine that forms with the central shell an output channel of the turbine, and annular outside shell that forms with the central shell diffuser output channel. The power-generating unit is equipped with an additional annular shell forming with external surfaces of the front and central shells narrowing-expanding first intermediate channel connected in its intermediate part to turbine output channel, while, with the internal surface of the outside shell, a second intermediate channel connected long with the first intermediate channel is used to diffuse the output channel.

Abstract: The variable-capacity turbine according to this invention is provided with a nozzle adjustment mechanism, having a nozzle drive components, a lever and nozzle vane, would all be housed at the inner side of the scroll in the turbine casing. This would reduce the axial length of the turbine and make it more compact, and thus easier to install in a car. It would also avoid the problem of the center casing becoming too complex. There would be fewer assembly and disassembly processes, and the turbine would be easier for maintenance. This variable-capacity turbine has nozzle drive members for the nozzles which is connected to an actuator that causes the drives member to rotate around the shaft turbine; and a nozzle adjustment mechanism which includes a number of connectors to link the nozzle drive members to the nozzle vanes.

Abstract: An exhaust gas turbine portion of a vehicle engine turbocharger is provided with at least one variable guide-blade cascade with guide blades in a nozzle opening to the turbocharger rotor for effectively changing the cross section of the exhaust flow to the rotor wherein the angle of the guide blades is selectively settable by an adjusting device. The width dimension of the gap between the ends of the guide-blade cascade and the casing wall defining the nozzle is adjustable between a substantially zero gap dimension and a maximum gap dimension.

Abstract: The present invention discloses a cooling system for temperature control, e.g., removing heat from electronic circuits. The cooling system includes a fan and an airflow guiding system where the guiding system includes an inlet air duct for guiding the airflow to the fan. The inlet air duct includes turbulence reduction grid for separating the air duct into a plurality of isolated flow path whereby the air turbulence is reduced. In a preferred embodiment, the airflow guiding system further includes an outlet duct for incorporating the fan therein wherein the outlet portion and the fan are directed to a direction different from the inlet air duct for guiding the airflow to the fan. In another preferred embodiment, the outlet duct and the fan are directed to a direction perpendicular to the inlet air duct for guiding the airflow to the fan.

Abstract: An annular diffuser having its inlet located at the exit of a last row of blades of a steam turbine having initially very slowly increasing cross-sectional area with distance to accommodate the diffusion produced by the decaying wakes in the diffuser so as to prevent flow separation from diffuser walls and as a result to foster the diffusion process and to increase the efficiency of the steam turbine. The rate of increase of cross-sectional area, which is much smaller than that appropriate in diffusers having uniform incompressible flow at their inlets, allows wakes which form near the trailing edges of the last turbine blades to dissipate while avoiding flow separation. In the diffuser of this invention, whether it is one of fixed shape or one whose cross-sectional area can be changed by making use of an adjustable guide vane which surrounds at least a portion of the bearing cone, at a distance from inlet of one half of diffuser height at inlet, the cross-sectional area increase is smaller than 5.

Abstract: A portable working machine provided with a centrifugal air blower, which is featured in that a prime mover (50) for driving the air blower (20) is mounted via a supporting coupling member (30) on a volute case (22) of the air blower (20) which is mounted in an upright state; and that an air inlet port of the air blower (20) is positioned on the side of the volute case (22) which is closer to the prime mover (50).