Method and apparatus for variable clearance packing
AssigneeGeneral Electric Company
InventorsRichard Chevrette, Frederick G. Baily
Life of this patent
Estimating the term…
Abstract
Methods and apparatus for a packing ring segment assembly for sealing a turbine gas path are provided. The assembly includes a sealing portion including radially inwardly directed teeth, and a dovetail mounting portion including a hollowed out portion including a biasing member internal to the packing ring segment. The biasing member is coupled to the packing ring segment and configured to engage a pair of annular shoulders of a dovetail groove in the turbine such that the packing ring segment is biasing radially outward at relatively low turbine loads and low working pressure, and at relatively high turbine loads and high working pressure a working fluid overcomes the radial biasing member forces and urge the packing ring segment radially inward.
Claims20
A packing ring segment assembly for sealing a gap between two regions of an article, said packing ring segment assembly comprising:
- a sealing portion including radially inwardly directed teeth;
- a dovetail mounting portion sized to slideably engage a pair of opposing shoulders that define a dovetail groove in the article, said dovetail mounting portion comprising a hollowed out portion that extends radially inward from an outer surface of said packing ring segment towards said sealing portion;
- a bracket positioned within said hollowed out portion, said bracket comprising a pair of legs extending generally radially outward from a base, each of said pair of legs comprising a bracket flange extending outward from said leg and contacting one of the shoulders when said dovetail mounting portion is coupled within said dovetail groove;
- and
- a biasing member positioned within said bracket, said biasing member coupled to said dovetail mounting portion and to said bracket, said biasing member is configured to urge said packing ring segment assembly radially outward at relatively low differential pressure between the two regions, and at a relatively high differential pressure between the two regions, the differential pressure overcomes the radial biasing member forces and urges said sealing portion radially inward, said dovetail portion movable in a first direction.
A turbine diaphragm for accommodating a rotor, said turbine diaphragm comprising:
- a diaphragm body having a radially inner bore and an inwardly recessed dovetail groove;
- a plurality of packing ring segments forming a seal ring between a first pressure region and a second pressure region wherein the first pressure is greater than the second pressure;
- wherein said dovetail groove includes a shoulder portion which defines a radial opening into said dovetail groove and wherein said shoulder portion includes an annular surface;
- and
- wherein each of said packing ring segments comprise a dovetail mounting portion at least partially enclosed in said dovetail groove and at least partially supported by said annular surface, said packing ring segments including a hollowed out portion that extends radially inward from an outer surface of at least one of said packing ring segments, said hollowed out portion including a bracket positioned within said hollowed out portion and a biasing member positioned within said bracket, said bracket comprising a pair of legs extending outward from a base, each of said pair of legs comprising a bracket flange extending outward from said leg and contacting said shoulder portion when said dovetail mounting portion is within said dovetail groove, said bracket and biasing member positioned between said packing ring segments and said annular surface such that said packing ring segments are biasing radially outward at relatively low turbine loads and low working pressure, and at relatively high turbine loads and high working pressure a working fluid will overcome the radial biasing member forces and urge said packing ring segments radially inward.
A turbine comprising:
- a stationary turbine casing surrounding a rotatable shaft, said casing comprising an annular T-shaped groove formed therein and extending circumferentially around said shaft, said annular groove being partially defined by a pair of opposing, spaced apart annular shoulders on said casing which form an annular opening of said groove radially into the clearance area between said casing and said shaft;
- and
- a segmented seal ring comprising a plurality of packing ring segments supported by and at least partially enclosed in said groove, said packing ring segments including a hollowed out portion that extends radially inward from an outer surface of at least one of said packing ring segments, said hollowed out portion including a bracket positioned within said hollowed out portion and a biasing member positioned within said bracket, said bracket comprising a pair of legs extending outward from a base, each of said pair of legs comprising a bracket flange extending outward from said leg and contacting one of said shoulders, said bracket and biasing member positioned between said packing ring segments and said annular shoulders such that said packing ring segments are biasing radially outward at relatively low turbine loads and low working pressure, and at relatively high turbine loads and high working pressure a working fluid will overcome the radial biasing member forces and urge said packing ring segments radially inward.
Dependencies are inferred from the claim text.