Abstract: A main engine mounted auxiliary power unit comprises an auxiliary power unit integrated with a primary gas turbine engine into a single power plant suited for aircraft applications. The auxiliary power unit can be mounted within an engine core compartment of the main engine or at the main engine aft center body. The integration of the auxiliary power unit provides for installation and certification cost savings to the airframer by eliminating the need for mounting an auxiliary power unit to the tail section of the aircraft.

Abstract: A main engine mounted auxiliary power unit comprises an auxiliary power unit integrated with a primary gas turbine engine into a single power plant suited for aircraft applications. The auxiliary power unit can be mounted within an engine core compartment of the main engine or at the main engine aft center body. The integration of the auxiliary power unit provides for installation and certification cost savings to the airframer by eliminating the need for mounting an auxiliary power unit to the tail section of the aircraft.

Abstract: A structure and a method to form the structure are provided for an impeller bleed passage of a compressor for a gas turbine engine. The compressor has an impeller assembly which includes an impeller rotor rotatably supported within an annular shroud having an inlet and an outlet. The shroud is made of two separate annular segments which are axially spaced apart. Each of the segments is supported separately and independently in a cantilevered manner. Such that a circumferentially continuous, uninterrupted annular slot is formed between the two segments and air passes through the slot without causing a dynamic component to affect the impeller rotor. The width of the slot is adjustable for different engines depending on the requirements of use of a particular engine. The width of the slot is also self-regulating in response to changes in the air pressure within the shroud because of the deformation of the segments. The structure is relatively simple and inexpensive to manufacture.

Abstract: The invention provides a novel sealing device and plenum assembly particularly adapted for forming a plenum inwardly of a circumferential stator blade array in a gas turbine engine. A Tangential On Board Injection plenum (T.O.B.I.) is defined by assembly of: a forward plate; a rearward plate; and a segmented inner shroud disposed between the forward and rearward plates. Releasable elongate fasteners are disposed in joints between a series of inner shroud segments with sealing sheaths laterally surrounding the fasteners. While clamping the shroud segments between the forward and rearward plates, the fasteners and sheaths simultaneously seal the joints and secure the inner shroud segments with forward and rearward plates in a rigid structural assembly.

Abstract: A bearing gallery thermal movement isolation device permits the inner bearing support ring of the bearing gallery to float freely relative to the outer bearing gallery housing under thermal expansion and contraction during engine operation without transmitting thermally induced movement or forces to the oil supply and scavenge lines, or to the cooling air supply line. An oil transfer tube isolation connector is disposed on an inward end of the transfer tube and on the bearing gallery. The connector includes a radially extending sleeve on the inner bearing support ring; and a sliding O-ring engaging the sleeve and transfer tube. An oil scavenge canal is defined between the O-ring and a threaded connection between the transfer tube and the oil supply boss of the bearing gallery.

Abstract: An annular support for supporting radial bearings and accommodating radial expansion and lateral displacement, and damping vibration of the bearing with respect to a static support structure includes an annular casing to support a bearing therein and a cantilevered support which has a first and second rings, axially spaced apart and connected by a plurality of flexible beams. The first ring is connected to the annular casing which is spaced radially, inwardly from the cantilevered support and the second ring is connected to the static support structure so that the flexibility of the beams permits the annular casing to move laterally in small distance while the annular support is supported to the static support structure. The flexibility is adjusted by selection of a combination of number, width and thickness of the beams. A service line is able to have an access between two adjacent beams to the annular casing to provide lubricating fluids.

Abstract: The present invention discloses a bleed valve for use in gas turbine engines. The valve has a piston, one end of which is positioned inside a housing which is positioned on one side of the by pass fluid flow path. The other end of the piston is positioned in an opening between the primary fluid flow path and the bypass fluid path such that the valve opens and closes in response to a pressure differential between two points in the primary fluid flow path.

Abstract: A ring gear (20) rotates circumferentially about a plain bearing (22) secured to the housing (10) of a centrifugal gas compressor. The ring gear (20) drives sector gears (18) for positioning variable guide vanes (14). A lever arm (32), actuator (36) and linkage (38, 40, 50) is provided for driving the ring gear (20).