Abstract: An embodiment of a disclosed apparatus for sizing an engine stator has a plurality of radially moveable shoes for engaging the inner and outer rings of the stator. The shoes apply a radially directed force to the inner and outer rings to cause the rings to expand. In particular embodiments, one or more heating mechanisms, such as a ceramic heating blanket, may be used to heat the stator prior to sizing. A method for sizing an engine stator also is disclosed. The method comprises simultaneously displacing the inner and outer rings of the stator generally radially outwardly so as to increase the respective diameters of the inner and outer rings.

Abstract: An embodiment of a disclosed apparatus for sizing an engine stator has a plurality of radially moveable shoes for engaging the inner and outer rings of the stator. The shoes apply a radially directed force to the inner and outer rings to cause the rings to expand. In particular embodiments, one or more heating mechanisms, such as a ceramic heating blanket, may be used to heat the stator prior to sizing. A method for sizing an engine stator also is disclosed. The method comprises simultaneously displacing the inner and outer rings of the stator generally radially outwardly so as to increase the respective diameters of the inner and outer rings.

Abstract: A method for imaging inclusions in metal or metal alloy castings is described. One embodiment of the present method first involves casting a metal or metal alloy article using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article.

Abstract: A method for imaging inclusions in metal or metal alloy castings is described. One embodiment of the present method first involves casting a metal or metal alloy article using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article.

Abstract: A molten metal or molten metal alloy is filtered to remove contaminants. Filters may include imaging agents, especially those useful for N-ray radiography, X-ray analysis, and neutron activation. Currently preferred imaging agents include gadolinia and tungsten. Currently preferred refractory materials include yttria, zirconia, tantalum, tungsten and rhenium. A homogeneous distribution of refractory and imaging materials may be accomplished by vacuum impregnation, chemical vapor deposition, physical vapor deposition, chemical vapor infiltration, fusing, cocalcining, alloying, and physical mixing. Filters substantially resistant to chemical and mechanical degradation may be used. For example, filters may be constructed with at least an outer layer of the filter comprising yttria. Filters may define a porosity and mesh size for efficient filtration and to exclude the maximum allowed size of defects for the particular application.

Abstract: A method for imaging inclusions in metal or metal alloy castings is described. One embodiment of the present method first involves casting a metal or metal alloy article using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article.

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.

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.

Abstract: A metal or metal alloy article is cast using an investment casting mold where the mold facecoat, and perhaps one or more of the mold backup layers, comprises an imaging agent distributed substantially uniformly throughout in amounts sufficient for imaging inclusions. The facecoat preferably comprises an intimate mixture of a refractory material and the imaging agent. Intimate mixtures can be produced in a number of ways, but a currently preferred method is to cocalcine the refractory material, such as yttria, with the imaging agent, such as gadolinia. The facecoat also can comprise plural mold-forming materials and/or plural imaging agents. The difference between the linear attenuation coefficient of the article and the linear attenuation coefficient of the imaging agent should be sufficient to allow imaging of the inclusion throughout the article. The metal or metal alloy article is then analyzed for inclusions by N-ray analysis.

Abstract: A metal article, at least a portion of which has a honeycomb structure, is described. The article was produced by an investment casting process. The metal casting comprises a base and plural walls which form a honeycomb structure that project outwardly in a first direction from at least a portion of the base. The base typically has a thickness of about 5 mm or less. The honeycomb structure may be defined by plural cells having geometric shapes. For instance, plural interconnected regular polygons, such as plural interconnected pentagons or hexagons, plural irregular interconnected polygons, or plural regular and irregular interconnected polygons may be used. The maximum distance between any two points on the periphery of the cell and passing through the interior space defined by the geometric shape is about 40 mm. The walls of the casting may have a wall thickness of from about 0.3 mm to about 3.2 mm thick.

Abstract: Sound absorptive fiberglass pads within a silencer device for a centrifugal compressor are precompressed while installing the device in a containing frame mounted in the discharge pipe by a process including the steps of establishing the transverse dimension of the frame as a function of the transverse thickness of the device, precompressing one end of the device to a thickness which allows its insertion into the frame, and then forcing the entire device into the cavity in a wedgelike manner to thereby precompress the entire device, to thereby precompress the absorptive pad to a desired degree for purposes of erosion prevention.