Abstract: An oil scavenging system for a main shaft bearing in a gas turbine engine includes a sump adjacent the bearing having a frustoconical inner surface and a constant diameter inner surface contiguous with the frustoconical surface. The small diameter end of the frustoconical surface is adjacent the bearing and the latter includes a low efficiency pumping member which pumps the oil onto the frustoconical inner surface with high tangential velocity. The oil centrifugally adheres to and migrates along the frustoconical surface and has sufficient tangential velocity to also centrifugally adhere to the constant diameter surface. The oil adhering to the constant diameter surface drains into drain entry in the constant diameter surface and is collected by a single scavenge pump pick-up regardless of engine attitude or altitude.

Abstract: A coupling between a continuously rotating input shaft and a selectively rotatable output shaft has a friction type transition clutch operative to accelerate the output shaft to synchronous speed and to permit controlled deceleration of the output shaft to rest and a spline type direct clutch parallel to the transition clutch engageable at synchronous speed to directly couple the input and output shafts. The spline clutch includes an input member having an input spline with a pressure face at a first helix angle, an output member having an output spline with a pressure face at a second, smaller helix angle, and a longitudinally shiftable intermediate member having a spline with a first pressure face at the first helix angle and a second pressure face at the second helix angle. The difference in helix angles effects circumferential separation between the output spline pressure face and the intermediate member spline second pressure face before the two splines separate longitudinally.

Abstract: A control system for a fluid pressure operated actuator includes an arming valve having open and closed positions and a pilot operated selector valve having a neutral position and an extend position. The arming valve is connected to a source of fluid and the selector valve is connected to the arming valve so that two control inputs are necessary to connect the source to an operating chamber of the actuator. A solenoid actuated pilot valve is connected to the source and to a sump and has an on position in which the flow of fluid is unblocked and in an off position in which the flow of fluid is blocked. A pilot passage connects the pilot valve to a pilot chamber of the selector valve and a branch passage connects the pilot passage and the operating chamber of the actuator so that the operating chamber communicates with the sump whenever the pilot valve is off regardless of the position of the selector valve.

Abstract: An improved vane actuation system for a gas turbine engine having adjustable stator vanes in stages between which the engine casing exhibits relative axial and radial thermal growth, the improved system including a pair of platforms on the casing forming therewith three bar link arrangements which automatically compensate for radial and axial thermal growth, rollers on each platform supporting vane actuation rings in centered relationship on the axis of the engine, connectors between the rings and the vane arms which locate the vanes but which permit radial expansion of the arms to accommodate radial thermal growth, a pair of bell cranks on each platform operated remotely and simultaneously, and links between each bell crank and corresponding ones of the rings operative to rotate the rings and, in combination with the rollers, to foreclose translation of the rings in their respective planes.

Abstract: In a turbomachine having a cylindrical casing, a stage of adjustable vane assemblies including vanes rotatable on the casing and actuating arms rotatable with the vanes, a unison ring around the casing, and bearing means between each actuating arm and the unison ring operative to rotate each arm in unison with the unison ring while permitting relative radial thermal growth of the vanes and arms incident to temperature changes during machine operation, a support system for the unison ring including three radially inwardly directed attachment nodes on the unison ring and three Bowden cable assemblies on the casing between the attachment nodes, the Bowden cable assemblies having push-pull elements capable of force transmission only lengthwise pivotally connected to each attachment node with ends directed generally tangent to a circle defined by the cable assemblies so that net forces exerted by the push-pull elements to support the unison ring are directed tangent to the circle.

Abstract: An improved mounting arrangement for an adjustable stator vane of a turbomachine, the vane having a shaft portion projecting through an outer casing of the turbomachine and an annular button portion disposed against a thrust bearing on the inside of the outer casing and the improvement residing in the provision of a spring around the shaft portion which bears at one end against a thrust bearing on the outer casing and at the other end against a rigid cantilever extension of the shaft portion of the vane so that the spring imposes on the shaft portion an offset force which develops a moment counter to a moment developed on the stator vane by passage of compressed gas through the turbomachine thereby to prevent cocking of the stator vane in the outer casing and to more evenly distribute loading on the button portion of the vane.

Abstract: A turbine rotor shroud is mounted by means for rigidly supporting it on an internal bearing for turbine and shaft components of a gas turbine engine and a low rate flexible seal member extends between the outer case of the gas turbine engine and an outer gas flow path wall for maintaining continuity of gas and air stream pass through the gas turbine engine during different modes of engine operation thereby to maintain a closely controlled clearance between blade tips of a row of turbine blades on a rotor connected to the gas turbine engine drive shaft and the rotor shroud to maintain close clearance under mechanical (static or dynamic) loads wherein the deflected rotor or engine casing systems move but the motion is accommodated by the flexible seal member and prevented by a rigid nozzle to turbine bearing support structure.

Abstract: A turbine blade tip seal assembly for controlling the blade tip clearance between a flexible outer shroud and the tips of a thermally expansible row of turbine blades on a turbine rotor includes a fixed outer shroud with a pressure deflectable wall portion thereon located in surrounding, radially outwardly relationship with blade tips on the blades of a turbine rotor and wherein an excessive blade tip to shroud wall spacing is maintained when the engine is at cold start conditions; said turbine blades of the turbine rotor expanding in response to increases in operating temperature within the engine during turbine engine operation to partially close the excessive blade tip to shroud clearance and further including pressurizable means responsive to turbine operation to produce pressure bias on the deflectable wall to cause it to be deflected raidally inwardly to further reduce the excessive blade tip clearance so as to produce a resultant operative clearance between the tip of the turbine rotor and the shroud t