US 2018/0023409 A1Published application

Turbine shroud with abradable layer having ridges with holes

AssigneeSiemens Aktiengesellschaft

InventorsChing-Pang Lee, Ramesh Subramanian, Kok-Mun Tham

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Abstract

Turbine and compressor casing abradable component embodiments for turbine engines vary localized porosity or abradability through use of holes or dimple depressions of desired polygonal profiles that are formed into the surface of otherwise monolithic abradable surfaces or rib structures. Abradable porosity within a rib is varied locally by changing any one or more of hole/depression depth, diameter, array pitch density, and/or volume. In various embodiments, localized porosity increases and corresponding abradability increases axially from the upstream or forward axial end of the abradable surface to the downstream or aft end of the surface. In this way, the forward axial end of the abradable surface has less porosity to counter hot working gas erosion of the surface, while the more aft portions of the abradable surface accommodate blade cutting and incursion with lower likelihood of blade tip wear.

Claims20

Dependent claims

A turbine engine ring segment component, adapted for coupling to an interior circumference of a turbine casing in opposed orientation with a rotating turbine blade tip circumferential swept path, the blade tip having a rotational direction, a leading edge, a mid-chord cutoff point on its pressure side concave surface and a trailing edge, the component comprising:

a curved support surface adapted for coupling to a turbine casing inner circumference, the support surface having upstream and downstream axial ends and a support surface curvature radius defined by a support surface central axis;
an abradable substrate coupled to the support surface, having a substrate surface with a plan form pattern of grooves and vertically projecting ridges facing the support surface central axis, the grooves and ridges originating and terminating axially between the support surface ends and defining forward and aft segment portions;
each forward segment portion originating nearer the support surface upstream end;
each aft segment portion originating at the adjoining forward segment termination and terminating nearer the support surface downstream end;
a pattern of indentations respectively having cross sectional profiles and depth, formed in the ridges, for selectively varying porosity and/or abradability of the respective ridge along the ridge axial length;
the forward linear segment portions defining a forward zone and the aft linear segment portions defining an aft zone;
the respective ridge pattern of indentations enhancing higher hot working gas erosion resistance in the forward zone than in the aft zone;
and enhancing greater porosity and abradability in the aft zone than in the forward zone.

5 more elements

A turbine engine, comprising:

a turbine housing including a turbine casing interior circumference;
a rotor having blades rotatively mounted in the turbine housing along a turbine blade rotational axis, distal tips of which forming a blade tip circumferential swept path in the blade rotation direction and axially with respect to the turbine casing interior circumference, each turbine blade having a leading edge, a mid-chord cutoff point on its pressure side concave surface and a trailing edge, oriented at a trailing edge angle relative to turbine blade rotational axis;
and
a ring segment component having:
a curved support surface coupled to the turbine casing inner circumference outwardly circumscribing the rotating turbine blade airfoil tips and the turbine blade rotational axis, the support surface having upstream and downstream axial ends and a support surface curvature radius defined by a support surface central axis that is parallel to the turbine blade rotational axis;
an abradable substrate coupled to the support surface, having a substrate surface with a plan form pattern of grooves and vertically projecting ridges facing the support surface central axis, the grooves and ridges originating and terminating axially between the support surface ends and defining forward and aft segment portions;
the forward segment portion originating nearer the support surface upstream end, and defining a forward zone;
the aft segment portion originating at the adjoining forward segment termination and terminating nearer the support surface downstream end, and defining an aft zone;
a pattern of indentations respectively having cross sectional profiles and depth, formed in the ridges, for selectively varying porosity and/or abradability of the respective ridge along the ridge axial length;
the respective ridge pattern of indentations enhancing higher hot working gas erosion resistance in the forward zone than in the aft zone;
and enhancing greater porosity and abradability in the aft zone than in the forward zone.

8 more elements

A method for enhancing operational service life of a turbine engine, comprising:

providing a turbine engine, having:
a turbine housing including a turbine casing interior circumference;
a rotor having blades rotatively mounted in the turbine housing along a turbine blade rotational axis, distal tips of which forming a blade tip circumferential swept path in the blade rotation direction and axially with respect to the turbine casing interior circumference, each turbine blade having a leading edge, a mid-chord cutoff point on its pressure side concave surface and a trailing edge, oriented at a trailing edge angle relative to turbine blade rotational axis;
and
a ring segment component having:
a curved support surface coupled to the turbine casing inner circumference outwardly circumscribing the rotating turbine blade airfoil tips and the turbine blade rotational axis, the support surface having upstream and downstream axial ends and a support surface curvature radius defined by a support surface central axis that is parallel to the turbine blade rotational axis;
an abradable substrate coupled to the support surface, having a substrate surface with a plan form pattern of grooves and vertically projecting ridges facing the support surface central axis, the grooves and ridges originating and terminating axially between the support surface ends and defining forward and aft segment portions;
the forward segment portion originating nearer the support surface upstream end, and defining a forward zone;
the aft segment portion originating at the adjoining forward segment termination and terminating nearer the support surface downstream end, and defining an aft zone;
and
forming a pattern of indentations in the ridges, the indentations respectively having cross sectional profiles and depth, for selectively varying porosity and/or abradability of the respective ridge along the ridge axial length;
the respective ridge pattern of indentations enhancing higher hot working gas erosion resistance in the forward zone than in the aft zone;
and enhancing greater porosity and abradability in the aft zone than in the forward zone.

10 more elements

Dependencies are inferred from the claim text.

Facts

Application: 15/548,481Filed 9 Dec 2015
Priority: 18 Feb 2015
Published: 25 Jan 2018
Term ends: Not estimatedThe source records don’t support an estimate.

Classification9 codes

F01D 11/122
Using a rubstrip, e.g. erodible. deformable or resiliently-biased part: with erodable or abradable material
F01D 9/04
Nozzles; Nozzle boxes; Stator blades; Guide conduits , e.g. individual nozzles: forming ring or sector
F05D 2220/32
In turbines: in gas turbines
F05D 2240/11
Stators: shroud seal segments

Family

Application15/548,481Continuation
US 10,190,435 B2Related patent
US 2018/0023409 A1This patent

From the US filing history. Foreign family members aren’t listed.

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