Dual-film damper
AssigneePratt & Whitney Canada Corp.
InventorsMert Cevik, Philip A. Varney, Robert J. Morris, David Beamish
Life of this patent
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Abstract
A dual-film damper has a housing defining an annular damper fluidly connected to a source of pressurized oil. First and second damper rings are coaxially nested within the damper cavity. A first set of spacers allows for the formation of a first oil film annulus between the first and second damper rings. A second set of spacers allows for the formation of a second oil film annulus between the second damper ring and the housing. The first and second oil film annuli have a thickness-to-length ratio (T/L) selected to provide a desired damping capacity.
Claims20
A dual-film damper in a gas turbine engine, comprising:
- a housing circumscribing an annular damper cavity around an axis and having an oil inlet connectable in flow communication with a source of pressurized oil;
- a first and a second damper ring coaxially nested within the annular damper cavity;
- a first pair of axially spaced-apart spacers positioned radially between the first and second damper rings, the first pair of axially spaced-apart spacers creating a first oil film annulus between the first and second damper rings;
- and
- a second pair of axially spaced-apart spacers radially between the second damper ring and the housing, the second set of spacers creating a second oil film annulus between the second damper ring and the housing, the second oil film annulus surrounding the first oil film annulus;
- each of the first and second oil film annuli having a thickness-to-length ratio (T/L) ranging from 0.0025 to 0.03.
A dual-film damper for damping radial movement of a rotary shaft relative to a rotation axis, the dual-film damper comprising:
- a housing defining an oil damper cavity around the rotation axis;
- at most two coaxially nested damper rings including first and second damper rings disposed in the oil damper cavity;
- a first annulus located radially between the first and second damper rings;
- a second annulus located radially between the second damper ring and the housing, the second annulus encircling the first annulus;
- and
- a first and a second pair of axially spaced-apart piston rings projecting respectively radially across the first annulus and the second annulus, the first and second pairs of axially spaced-apart piston rings defining a thickness T and a length L of the first annulus and the second annulus, respectively;
- wherein a thickness-to-length ratio (T/L) ranges from 0.0053 to 0.025.
A dual-film damper for damping radial movement of a rotary shaft relative to a rotation axis, the dual-film damper comprising:
- a housing defining an oil damper cavity around the rotation axis;
- at most two damper rings including first and second damper rings disposed in the oil damper cavity, the second damper ring encircling the first damper ring;
- a first oil film annulus located radially between the first and second damper rings;
- a second oil film annulus located radially between the second damper ring and the housing;
- and
- a first and a second pair of spacer rings respectively projecting radially across the first oil film annulus and the second oil film annulus, the first and second pairs of spacer rings respectively defining a thickness T and a length L of the first oil film annulus and the second oil film annulus, wherein the length L ranges from 1000 mils (25.4 mm) to 2000 mils (50.8 mm), wherein the thickness T of the first oil film annulus ranges from 5 mils (0.127 mm) to 30 mils (0.762 mm), and wherein the thickness T of the second oil film annulus ranges from 2.5 mils (0.051 mm) to 45 mils (1.143 mm).
Dependencies are inferred from the claim text.