Abstract: A rotary bearing system that supports a shaft for rotating machinery in a housing comprises: at least one stationary rotary bearing mounted in the housing for supporting a respective journal of the shaft in a desired axial and radial alignment; at least one slidable rotary bearing, with an outer surface mounted within a respective inner support surface of the housing to form a respective linear bearing such that each slidable bearing may slide axially along the inner support surface of the housing, for supporting another respective journal of the shaft with the desired radial alignment; and at least one layer of a crystalline material that exhibits a high degree of basal cleavage bonded to at least one of the linear bearing surfaces; wherein each layer of crystalline material allows each slidable rotary bearing to slide axially along each respective linear bearing to compensate for differences in the coefficient of expansion of the housing and the shaft so as to prevent the bearing system from binding due to

Abstract: A fuel delivery system for a gas turbine engine that delivers fuel to a combustor of the engine and lubricates bearings of the engine with fuel, comprising: a tank for storing the fuel; a pump for delivering a continuous flow of fuel from the tank to the combustor by way of a combustor inlet stream and the engine bearings by way of a bearing lubrication stream; a pressurized container for storing fuel lubrication additive under pressure; and a flow valve for controlling flow of fuel lubrication additive that flows from the pressurized container into the bearing lubrication inlet stream to mix with the fuel delivered to the engine bearings.

Abstract: A thermal management system and method for a miniature gas turbine engine includes a forward cover having a filter portion along an axis of rotation of a gas turbine engine, a first lubrication passage and a second lubrication passage.

Abstract: A rotary bearing system that supports a shaft for rotating machinery in a housing comprises: at least one stationary rotary bearing mounted in the housing for supporting a respective journal of the shaft in a desired axial and radial alignment; at least one slidable rotary bearing, with an outer surface mounted within a respective inner support surface of the housing to form a respective linear bearing such that each slidable bearing may slide axially along the inner support surface of the housing, for supporting another respective journal of the shaft with the desired radial alignment; and at least one layer of a crystalline material that exhibits a high degree of basal cleavage bonded to at least one of the linear bearing surfaces; wherein each layer of crystalline material allows each slidable rotary bearing to slide axially along each respective linear bearing to compensate for differences in the coefficient of expansion of the housing and the shaft so as to prevent the bearing system from binding due to

Abstract: A bearing lubrication system for a gas turbine engine that has bearings supporting a rotor shaft comprises a housing for the engine that serves as a primary static structural support; a rotor shaft for mounting rotational components of the engine; at least two bearings for supporting the rotor shaft within the housing, each bearing comprising an inner race that couples to the rotor shaft comprising a plurality of inner race lubricant apertures that extend radially through the inner race that supply pressurised lubricant to selected regions within the bearing, an outer race that couples to a primary static structural support, a plurality of ball elements between the inner race and the outer race and a ball cage to maintain the relative radial spacing of the ball elements between each other within the inner race and the outer race; and a lubricant distribution system for delivering pressurised lubricant to the inner race apertures in each of the bearings.

Abstract: A ball bearing assembly for a gas turbine engine comprises an inner race that couples to a rotor shaft; an outer race that couples to a primary static structural support; a plurality of ball elements between the inner race and the outer race; and a ball cage that comprises a carbon-carbon composite material to maintain the relative radial spacing of the ball elements between each other within the inner race and the outer race after subjection to high loads, heat generation and long-term storage.

Abstract: A speaker system includes a speaker driver loaded by a horn waveguide. The speaker driver reproduces sound within an extended frequency range that includes a high frequency band between 8 kHz and 11 kHz. In the preferred embodiment, the extended frequency range includes a wide frequency band between 2 kHz and 11 kHz (and most preferably including the frequency band between 800 Hz and 11 kHz). The horn waveguide has an axi-symmetrical waveguide surface that provides uniform polar dispersion at dispersion angles greater than 90 degrees for sound within the extended frequency range. The waveguide surface preferably has an annular cross section with a radial dimension that increases curvilinearly from its throat to its mouth, such as a tractroid surface.

Abstract: An abradable coating is provided for use on a composite substrate which has a coefficient of thermal expansion substantially similar to that of the substrate and which is formed with a matrix resin of the same type of resin used to form the substrate. In particular, with a composite substrate formed from carbon or graphite fibers impregnated with a polyimide resin, an abradable coating formed from carbon or glass microballoons in a polyimide resin matrix has been found to avoid delamination as a result of thermal cycling between -65.degree. F. and 500.degree. F. Accordingly, that abradable coating is particularly suitable for use with composite compressor shrouds in gas turbine engines and aircraft auxiliary power units.