Abstract: A bladed rotor (19) suitable for a gas turbine engine (10) comprises a plurality of aerofoil blades (21) mounted on the periphery of a disc (20). Each of the aerofoil blades (21) has a root part (25) which locates in the disc (20) and is constituted by two radially extending circumferentially spaced apart root portions (26,27). The circumferentially outward flanks of the root portions (26,27) are configured to define a fir-tree type blade fixing which locates in a correspondingly shaped recess (34) in the disc (20). The root part (25) configuration provides weight reduction in the rim region of the disc (20), thereby reducing stresses within the disc (20).

Abstract: A volute type centrifugal pump has an impeller rotatably mounted in a volute chamber of the pump casing adjacent a cutwater within the casing. The impeller includes a hub having a pair of diametrically extending vanes with the outer end portion of each vane being angled in a trailing direction relative to the direction of rotation of the impeller. A semi-cylindrical projection having an axis parallel to the axis of the hub is formed on a trailing surface of each angled portion adjacent an outermost end thereof thereby reducing cavitation on the trailing surface of the impeller to reduce drag and turbulence while increasing pressure on the trailing surface. The surface of the semi-cylindrical projection is roughened to enhance hydraulic jump.

Abstract: Clearance control is provided by circumferentially segmented cooling manifolds having spray bars located radially outside selected components of the stator casing. Cooling air is directed onto stator components and returns immediately through circuitous paths to improve uniformity of cooling. The spray bars extend through limited circumferential angles to limit distortion due to uneven heating.

Abstract: An apparatus and method are provided for minimizing differential thermal expansion in external cooling air structures formed on the shrouds of the vane segments of a gas turbine. The external cooling air structure is formed from a laminate comprised of two layers joined in sandwich-like fashion. A passageway, which may be of a serpentine arrangement, is formed between the two layers of the laminate. Hot gas flowing over the shroud is directed through the passageway, thereby heating the structure so that its temperature is close to that of the shroud. Cooling air is bled into the hot gas directed to the passageway so as to reduce the temperature of the hot gas flowing through the passageway and prevent overheating of the external cooling air structure.

Abstract: An improved seal design is provided for use in a gas turbine engine. A corrugated facing strip, with a reduced corrugation height, is attached to the exposed end faces of a seal land to reduce windage losses at the exposed end faces. The corrugated facing strip simplifies construction of the seal land and provides a low windage loss surface at seal end faces.

Abstract: The casing of a turboshaft engine, particularly a turbojet engine with a high speed propeller, comprises axially successive shells which are fixed firmly to each other end to end by bolted coupling flanges, at least one of the shells comprising an additional mechanical axial retaining joint enabling the connection between the shells to withstand any exceptional stresses such as those caused by the loss of a propeller blade of the turbojet engine. Preferably the retaining joint comprises a radially inwardly directed tongue carried by one of the shells and received in a radially outwardly open groove provided in a portion of the other shell or a member securely fixed thereto.

Abstract: A molded, composite, airfoil-defining, synthetic resin blade for large diameter cooling tower fans is disclosed wherein a moderately dense synthetic resin foam core is first formed that is generally of the same size and shape as the final desired blade. A shank embedded in the foam core extends outwardly from the end of the blade that is adapted to be fastened to the fan hub. A skin of fiberglass reinforced synthetic resin material is placed over the foam core with the thickness of the skin being greatest at the hub end of the blade and especially around the shank. The foam core with the skin thereon is molded into the final desired configuration thereof under pressure and temperature conditions such that the core is compressed and the thickness reduced to an extent correlated with the thickness of the synthetic resin skin on opposite faces thereof.

Abstract: A blade tip clearance control arrangement for a compressor of a gas turbine engine comprises a first annular control member which defines a portion of the gas flowpath through the compressor and which is spaced from the tips of the rotor blades by a clearance. The first annular control member is positioned coaxially inwardly of a pair of second annular control members and is secured thereto by a radially resilient annular support member.The first annular control member is formed from a relatively low expansion material and the second annular control members are formed from a relatively high expansion material.

Abstract: A windage shield for use with a pair of annular members oriented in an abutting end-to-end arrangement to define one boundary of a fluid flow path, each of the members having a radially extending flange at their respecting abutting ends for coupling the members to each other. The flanges are coupled by a plurality of circumferentially spaced bolts having a head and a nut which protrude into the fluid flow path. The windage shield comprises an annular ring having a first surface with a plurality of circumferentially spaced arcuate grooves formed therein. Each of the grooves is shaped to receive a preselected number of the bolt heads when the ring is positioned against a corresponding flange. A second surface of the ring opposite the first surface includes a plurality of apertures extending through the ring to the first surface with each of the apertures being located between a respective adjacent pair of the arcuate grooves. Each aperture has a countersunk portion on the second surface.

Abstract: A two part vane (38) comprises a metallic downstream portion (42) and a high temperature leading edge insert (40) disposed between two retaining buttons (46,48) loosely fit into recesses (50) formed in the inner platform (52) and the outer platform. The separation between the leading edge insert (40) and the downstream portion (42) creates two cooling louvers (64,66) for conducting cooling air from an internal cavity (58) through the cooling louvers (64,66) and down the surfaces (54,56) of the downstream portion (42).

Abstract: A rotating fluid machine for reversible operation from turbine to pump and from pump to turbine having a simple structure which allows for easy manipulation when reversing operation, and having a low change in efficiency when the machine operates in reverse. The fluid machine includes a bladed rotor containing a rotor spindle, a rotor disk, at least one radial groove, a carrying pin integral to the rotor disk, and at least one rotor blade. The blade, which controls the fluid flow, possesses two identical tongues that extend symmetrically with respect to the axis of the carrying pin and protrude with respect to the rotor disk. The machine possesses an external duct for input of the fluid to the fluid duct. The blade of the carrying pin then rotates in accordance with the toroidal structure of the bladed rotor, allowing the fluid to pass through three passages and to exit by way of a second external duct.

Abstract: An impeller for a centrifugal pump has a hub which is designed to be affixed to the pump shaft. The hub carries a first cover plate which is located at the pressure side of the impeller and supports a series of vanes defining flow channels. The first cover plate is secured to the bases of the vanes and a second cover plate situated at the suction side of the impeller abuts the tops of the vanes and overlies the flow channels. A suction port constituting an individually manufactured component is disposed at the inlet of the impeller and has a section of constant diameter which faces away from the vanes as well as a section of variable diameter which confronts the vanes. The section of variable diameter is connected to the tops of the vanes by a weld seam. The second cover plate overlies that end portion of the suction port having the greatest diameter and is secured to the tops of the vanes in an area between the suction port and the impeller outlet.

Abstract: A turbine blade shroud assembly for a gas turbine engine includes a metal substrate ring on the engine, a continous ceramic barrier ring inside the substrate ring and exposed to hot gas in a hot gas flow path of the engine, and a wire mesh compliant ring between the barrier and substrate rings. The temperature of the barrier ring increases faster than the temperature of the substrate ring as the temperature in the hot gas flow path increases. The coefficient of thermal expansion of the substrate ring is less than the coefficient of thermal expansion of the barrier ring so that the barrier ring expands relative to the substrate ring with increasing temperature in the hot gas flow path and development of tensile hoop stress in the ceramic barrier ring is minimized.

Abstract: The present invention provides for the removable attachment of sealing segments about the entire circumferential periphery of the rotor spacer discs. To this end, the conventional annular grooves provided in the peripheral surface of each spacer disc (as part of the high/low sealing surface configuration) are reconfigured as dovetail grooves which are designed to receive complimentary or mating portions of the sealing segments. In other words, each adjacent annular groove receives a plurality of sealing segments, the totality of which substantially prevent or at least minimize the impingement of hot gases directly on the peripheral surface of the spacer disc.

Abstract: A turbine support for reacting structural loads from a rotor bearing cage to a case of a gas turbine engine. The turbine support includes a homogeneous main casting and a rotor bearing cage. The main casting has concentrically arranged inner, intermediate and outer walls. The bearing cage is radially inboard and a rigid appendage of the inner wall. The inner and intermediate walls define therebetween a longitudinal segment of the annular hot gas flow path of the engine. The outer wall is bolted to the engine case. The inner wall is connected to the intermediate wall by a plurality of generally radially oriented, angularly separated inner load bearing struts of the main casting. The outer wall is connected to the intermediate wall by a plurality of radially oriented, angularly separated outer load bearing struts of the main casting.

Abstract: A method of diffusing airflow includes diffusing first and second airflow portions at first and second diffusion rates, respectively, which are unequal for improving pressure recovery. An exemplary diffuser for practicing the invention includes first and second channels separated by a splitter for separately diffusing first and second airflow portions, respectively. The first and second channels have first and second area ratios, respectively, which are unequal for obtaining increased pressure recovery. In the preferred embodiment, the first and second area ratios are preselected for obtaining substantially symmetrical airflow streamlines over a leading edge of the splitter.

Abstract: A liquid ring vacuum pump includes a vacuum pump housing composed by two opposed end walls spaced by an annular wall defining a vacuum pump chamber; a shaft extends into the vacuum pump chamber; a rotor is mounted on the shaft and is arranged eccentrically in the chamber; the rotor includes a rotor central portion and a plurality of vacuum pump vanes extending therefrom toward the annular wall; the rotor central portion and the vanes having at least one lateral edge adjacent the end walls facing the annular wall, the lateral edges and the end walls form a clearance therebetween; and the clearance between the edges and at least one of the adjacent end walls of the vacuum pump chamber increases towards the annular wall. A combination of the liquid ring vacuum pump with a centrifugal pump for pumping multi-phase liquids such as gas and solids containing fiber suspensions of the pulp and paper industry is also provided.

Abstract: In a gas turbine engine having a ceramic nozzle guide vane supported by a metal turbine casing the radially outer end of the vane is provided with opposed frustoconical sections which converge towards each other onto a middle cylindrical section. A metal split ring surrounds the cylindrical section, and the radially inner and outer ends of the ring abut the frustoconical sections. The split ring is provided with a flange which cooperates with a groove structure on the turbine casing, thus enclosing the split ring to the casing. A bolt means fastens together two sections of the casing either side of the vane, thereby holding the split ring against the vane. On increase in temperature the split ring expands more than does the vane. The ends of the split ring therefore slide against the frustoconical surfaces of the vane to take up the expansion, and in so doing maintain contact with the vane.

Abstract: A hydraulic positioning means is provided which includes means for selectively allowing or prohibiting the flow of the first hydraulic fluid under the operating pressure. It also includes means in the hydraulic positioning means for selectively positioning the workpiece to a plurality of predetermined locations for performing work operations thereon in response to allowing or prohibiting the flow of the first pressurized hydraulic fluid under the operating pressure. Means are also furnished for supplying the first pressurized fluid under the operating pressure to the hydraulic positioning means for such selective positioning of the workpiece. First fluid conduit means transfer the first pressurized fluid at said operating pressure from the pressurized fluid supply means to the hydraulic positioning means. A hydraulic impact load cushioning means is also bifurcatedly provided.

Abstract: A fan device for a refrigerator includes a hollow wall having a front wall portion and a rear wall portion for dividing an interior space of the refrigerator into a heat exchanging zone and a first portion of a storage zone. An air suction opening is formed in the rear wall portion for allowing an air cooled in the heat exchanging zone to be induced into the hollow wall. A fan is disposed in alignment with the air suction opening so as to induce the cooled air. A plurality of forward air outlet slots are formed in the front wall portion for allowing the air in the hollow wall to be blown to the first portion of the storage zone. A rearward air outlet is formed in the rear wall portion for allowing the air in the hollow wall to be blown to a second portion of the storage zone through a duct communicating the rearward air outlet to the second portion.