Abstract: A sequential stiffness support is provided for a bearing assembly to improve vibration characteristics of a gas turbine engine and to provide a variable structural stiffness to the support to minimize unbalance load transmissibility. In one embodiment, and by way of example only, the sequential stiffness support includes an inner ring, an outer ring, and means for coupling the inner ring and the outer ring. The sequential stiffness support is configured to provide a first stiffness support at a first engine speed and a second stiffness support at speeds greater than the first engine speed. Methods of manufacturing the sequential stiffness support are also provided.

Abstract: A support damper is provided for a bearing assembly to improve the damping capabilities of an uncentered squeeze film damper and to provide a support structure stiffness to minimize rotor to structure unbalance response. In one embodiment, and by way of example only, the support damper includes an inner ring, an outer ring, and U-shaped beams. The inner ring is configured to be disposed around the bearing assembly and to extend axially along a portion thereof. The outer ring is spaced apart from the inner ring and extends radially outwardly relative thereto. The U-shaped beams couple the inner ring to the outer ring. Methods of manufacturing the support damper are also provided.

Abstract: A squeeze film damper is provided that includes a fluid source, a shaft, a bearing assembly, a static bearing support, and a dam. The shaft includes openings formed therein and an annular channel in communication therewith that is configured to receive fluid from the fluid source. The bearing assembly is disposed concentric to the shaft and includes an inner race coupled to the shaft, an outer race disposed concentric to the inner race, and a rolling element disposed between the inner and outer races. Each of the inner and outer races includes openings configured to receive fluid from the shaft opening. The static bearing support housing is spaced apart from the outer race to define a clearance therebetween. The dam is disposed adjacent the bearing assembly and extends radially inwardly relative to the bearing support housing defining a shelf for receiving the fluid from the race openings and directing the fluid into the clearance.

Abstract: A sequential stiffness support is provided for a bearing assembly to improve vibration characteristics of a gas turbine engine and to provide a variable structural stiffness to the support to minimize unbalance load transmissibility. In one embodiment, and by way of example only, the sequential stiffness support includes an inner ring, an outer ring, and means for coupling the inner ring and the outer ring. The sequential stiffness support is configured to provide a first stiffness support at a first engine speed and a second stiffness support at speeds greater than the first engine speed. Methods of manufacturing the sequential stiffness support are also provided.

Abstract: A shaft oil purge system comprises an entrance seal, an exit seal and a buffer air flow. The entrance seal comprises a circumferential carbon seal running on an inner shaft and another carbon seal running on an outer shaft. The exit seal comprises a labyrinth seal positioned on the inner shaft and towards the exit end of the annulus between the shafts. An abradable material filled groove positioned radially outward from the exit seal allows the inner shaft to rub without compromising the integrity of the outer shaft. The buffer air flow enters the annulus from a cavity at the entrance seal, purges oil from the annulus and improves the efficiency of the seals.

Abstract: A support damper is provided for a bearing assembly to improve the damping capabilities of an uncentered squeeze film damper and to provide a support structure stiffness to minimize rotor to structure unbalance response. In one embodiment, and by way of example only, the support damper includes an inner ring, an outer ring, and a U-shaped beams. The inner ring is configured to be disposed around the bearing assembly and to extend axially along a portion thereof. The outer ring is spaced apart from the inner ring and extends radially outwardly relative thereto. The U-shaped beams couples the inner ring to the outer ring. Methods of manufacturing the support damper are also provided.

Abstract: An apparatus and method that provides a flexible anisotropic support, which may accommodate open, closed, or re-circulating squeeze film damper in parallel, has improved internal rolling element clearances, limits maneuver and blade loss responses by limiting rotor excursion, and has a rotor centering feature. This is accomplished through the combination of beam and ring arrangement, which provides support anisotropy that produces beneficial cross-coupling stiffness for the support to control synchronous and non-synchronous vibration.

Abstract: An apparatus and method that provides a flexible anisotropic support, which may accommodate open, closed, or re-circulating squeeze film damper in parallel, has improved internal rolling element clearances, limits maneuver and blade loss responses by limiting rotor excursion, and has a rotor centering feature. This is accomplished through the combination of beam and ring arrangement, which provides support anisotropy that produces beneficial cross-coupling stiffness for the support to control synchronous and non-synchronous vibration.