Abstract: An apparatus and method for cooling a wall for use in a gas turbine engine is provided that includes a cooling air passage having a plurality of segments connected in series by one or more chambers, an inlet aperture, and an exit aperture. The inlet aperture connects the cooling air passage to one side of the wall. The exit aperture connects the cooling air passage to the opposite side of the wall. Cooling air on the inlet aperture side of the wall enters the cooling air passage through the inlet aperture and exits through the exit aperture.

Abstract: A method and apparatus for cooling a wall within a gas turbine engine is provided which comprises the steps of: (1) providing a wall having an internal surface and an external surface; (2) providing a cooling microcircuit within the wall that has a passage for cooling air that extends between the internal surface and the external surface; and (3) increasing heat transfer from the wall to a fluid flow within the passage by increasing the average heat transfer coefficient per unit flow within the microcircuit. According to one aspect, the present invention method and apparatus can be tuned to substantially match the thermal profile of the wall at hand.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: A hollow airfoil is provided which includes a body, a trench, and a plurality of cooling apertures disposed within the trench. The body extends chordwise between a leading edge and a trailing edge, and spanwise between an outer radial surface and an inner radial surface, and includes an external wall surrounding a cavity. The trench is disposed in the external wall along the leading edge, extends in a spanwise direction, and is aligned with a stagnation line extending along the leading edge.

Abstract: A hollow airfoil is provided which includes a body having an external wall and an internal cavity. The external wall includes a suction side portion and a pressure side portion. The portions extend chordwise between a leading edge and a trailing edge and spanwise between an inner radial surface and an outer radial surface. A stagnation line extends along the leading edge. A plurality of cooling apertures, disposed spanwise along the leading edge. According to one aspect of the present invention, the apertures extend through the external wall along a helical path. According to another aspect of the present invention, the apertures are alternately directed towards the suction side portion and the pressure side portions of the airfoil.

Abstract: A document transport for a scanner (100) has a flexible, elongated finger (226) disposed adjacent to a document (134), and a force applied to the finger (226) urges teeth (233) on the finger (226) into contact with the document (134) which urges the document (134) along a path through the scanner (100). A piezoelectric plate (222), which applies the force to the finger (226), requires only a small amount of electrical power. To traverse the scanner (100), a document (134) may also be manually fed along a guide (272). First and second speed-sensing detectors (276a and 276b), disposed along the path traversed by the document (134), permit the scanner (100) to determine a speed at which the manually fed document (134) traverses the scanner (100). To conserve electrical energy, the scanner (100) also includes a document-presence detector (274) for activating the scanner (100) when a document (134) to be scanned is present.

Abstract: A hollow airfoil is provided which includes a body, a trench, and a plurality of cooling apertures disposed within the trench. The body extends chordwise between a leading edge and a trailing edge, and spanwise between an outer radial surface and an inner radial surface, and includes an external wall surrounding a cavity. The trench is disposed in the external wall along the leading edge, extends in a spanwise direction, and is aligned with a stagnation line extending along the leading edge.

Abstract: A differential case is provided including at least one assembly window formed therein for providing access to a chamber interior of the differential case. The assembly window in the differential case is defined by a pair of opposed circular edge portions of the differential case interconnected by a pair of opposed elongated edge portions of the differential case. The pair of opposed elongated edge portions have a dimension therebetween slightly larger than an outside diameter of a pair of side gears so as to allow angulated entry of the side gears into the chamber and subsequent alignment relative to a longitudinal axis. The pair of opposed circular edge portions include a radius slightly larger than a radius of a pair of pinion gears to allow entry of the pinion gears into the chamber and subsequent alignment relative to another longitudinal axis.

Abstract: Intersecting judiciously located installed holes at the tip section of the airfoil of an internally cooled axial flow turbine blade for a gas turbine engine communicating with a passage adjacent the pressure side and another passage adjacent the suction side of the airfoil provide a resultant flow that creates an aerodynamic seal that opposes the flow of engine working medium leaking into the clearance between the tip of the airfoil and the surrounding annular shroud or outer air seal. The installed holes are in proximity to the intersection of the tip surface with the airfoil pressure side surface.

Abstract: An article is provided, comprising a structure and a coating for minimizing thermal gradients in the structure. The coating includes a plurality of first layers of thermally conductive material, and a plurality of second layers of thermally conductive material. The first layers of thermally conductive material are less thermally conductive than the second layers at any particular temperature, and the layers are applied to the article such that the second layers of thermally conductive material are distributed amongst the first layers of thermally conductive material. Conduction of thermal energy through the layers to the structure is substantially impeded within the first layers, and substantially laterally dispersed within the second layers, thereby minimizing any thermal gradients within the structure.

Abstract: A drive axle assembly has a gear housing, two axle tubes extending outwardly of the gear housing, a lubricant reservoir in the gear housing and a gear assembly rotatably mounted in the gear housing that has a rotatable member that is partially disposed in lubricant in the lubricant reservoir. The drive axle assembly also has a lubricant cooling system that includes a lubricant passage in fluid communication with the lubricant reservoir via an inlet that is juxtaposed the rotatable member so that the level of lubricant in the lubricant passage is raised when the rotatable member rotates. The lubricant passage has elevated outlets that deliver lubricant to lubricant ducts disposed in the respective axle tubes when the lubricant in the lubricant passage rises above a predetermined level. The lubricant flows away from the gear housing in the lubricant ducts and returns to the reservoir along the interior of the axle tubes which cools the lubricant as it returns to the reservoir.