Abstract: A method of bowed rotor start response damping for a gas turbine engine is provided. A spring rate and a damping characteristic of one or more bearing supports in the gas turbine engine are selectively modified while a shaft of the gas turbine engine rotates below a speed which is adversely affected by a bowed rotor condition of the gas turbine engine.

Abstract: A method of bowed rotor start response damping for a gas turbine engine is provided. A spring rate and a damping characteristic of one or more bearing supports in the gas turbine engine are selectively modified while a shaft of the gas turbine engine rotates below a speed which is adversely affected by a bowed rotor condition of the gas turbine engine.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: A bearing assembly is provided. The bearing assembly includes an inner race configured to couple to a shaft, an outer race disposed around the inner race, and a housing disposed around the outer race. The housing and the outer race define an annulus and a buffer region, and the buffer region defines an axial boundary of the annulus.

Abstract: A squeeze film damper includes a static member and a whirling member positioned adjacent to the static member. A gap is formed between the static member and the whirling member. A pressurized oil reservoir is formed in the gap between the static member and the whirling member. A first low pressure oil reservoir is formed in a first cavity in the whirling member, wherein the first low pressure oil reservoir is positioned on a first end of the pressurized oil reservoir. A second low pressure oil reservoir is formed in a second cavity in the whirling member, wherein the second low pressure oil reservoir is positioned on a second end of the pressurized oil reservoir. A first primary seal is positioned between the first end of the pressurized oil reservoir and the first low pressure oil reservoir, and a second primary seal is positioned between the second end of the pressurized oil reservoir and the second low pressure oil reservoir.

Abstract: A squeeze film damper includes a static member and a whirling member positioned adjacent to the static member. A gap is formed between the static member and the whirling member. A pressurized oil reservoir is formed in the gap between the static member and the whirling member. A first low pressure oil reservoir is formed in a first cavity in the whirling member, wherein the first low pressure oil reservoir is positioned on a first end of the pressurized oil reservoir. A second low pressure oil reservoir is formed in a second cavity in the whirling member, wherein the second low pressure oil reservoir is positioned on a second end of the pressurized oil reservoir. A first primary seal is positioned between the first end of the pressurized oil reservoir and the first low pressure oil reservoir, and a second primary seal is positioned between the second end of the pressurized oil reservoir and the second low pressure oil reservoir.

Abstract: A film damper for a gas turbine engine includes an annular inner member and an annular outer member located radially outboard of the annular inner member, the annular outer member and the annular inner member defining a damper annulus therebetween. A fluid supply passage delivers a flow of fluid into the damper annulus from the annular outer member, and a backflow prevention device is located at the fluid supply passage to prevent backflow of the flow of fluid from the damper annulus into the fluid supply passage.

Abstract: A bearing assembly is provided. The bearing assembly may include an inner race configured to couple to a shaft, an outer race disposed around the inner race, a bearing support structure coupled to the outer race, and a housing disposed around the bearing support structure. The housing and the bearing support structure may define a squeeze-film damper annulus configured to receive an aerated damping fluid. The aerated damping fluid may be provided from a fluid pump and an air supply port.

Abstract: A bearing assembly is provided. The bearing assembly includes an inner race configured to couple to a shaft, an outer race disposed around the inner race, and a housing disposed around the outer race. The housing and the outer race define an annulus and a buffer region, and the buffer region defines an axial boundary of the annulus.

Abstract: A film damper for a gas turbine engine includes an annular inner member and an annular outer member located radially outboard of the annular inner member, the annular outer member and the annular inner member defining a damper annulus therebetween. A fluid supply passage delivers a flow of fluid into the damper annulus from the annular outer member, and a backflow prevention device is located at the fluid supply passage to prevent backflow of the flow of fluid from the damper annulus into the fluid supply passage.

Abstract: A method of bowed rotor start response damping for a gas turbine engine is provided. A spring rate and a damping characteristic of one or more bearing supports in the gas turbine engine are selectively modified while a shaft of the gas turbine engine rotates below a speed which is adversely affected by a bowed rotor condition of the gas turbine engine.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: A bearing for a gas turbine engine may comprise a squeeze film damper. A bearing housing may comprise a roughened surface. The roughened surface may increase friction between the bearing housing and the oil in the squeeze film damper. The increased friction may increase the damping force in the squeeze film damper. The increased damping force may prevent oil inertia, and prevent resonant vibrations.

Abstract: A bearing for a gas turbine engine may comprise a squeeze film damper. A bearing housing may comprise a roughened surface. The roughened surface may increase friction between the bearing housing and the oil in the squeeze film damper. The increased friction may increase the damping force in the squeeze film damper. The increased damping force may prevent oil inertia, and prevent resonant vibrations.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: An example gas turbine engine includes a turbine and first and second spools coaxial with one another. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool and supports the turbine. A housing is arranged downstream from the turbine. First and second bearings are mounted to the aft end of the first spool and supported by the housing portion.

Abstract: An example gas turbine engine includes a housing and first and second spools coaxial with one another and arranged within the housing. The first spool is arranged within the second spool and extends between forward and aft ends. The aft end extends axially beyond the second spool. First and second bearings support the aft end of the first spool relative to the housing. An example method of assembling the gas turbine engine includes arranging a first spool within a second spool. First and second bearings are mounted between an aft end of the first spool and a fixed housing.