Rotor blade tip clearance
AssigneeUnited Technologies Corporation
InventorsDavid J. Wasserman, Michael G. McCaffrey, Michael G. Abbott
Life of this patent
Estimating the term…
Abstract
A system includes, in one example, a shroud configured to circumscribe a plurality of rotor blades of a gas rotor engine, and at least one rub button including a head portion having a height configured to extend into a flow path region of the shroud along a central axis of the rub button that extends radially into the flow path region. The head portion includes a profile, orthogonal to the central axis, that varies according to a defined function of the height of the head portion.
Claims18
A system comprising:
- a shroud configured to circumscribe a plurality of rotor blades of a gas turbine engine;
- and
- at least one rub button comprising:
- a head portion having a height configured to extend into a flow path region of the shroud along a central axis of the rub button that extends radially into the flow path region, the head portion comprising a profile, orthogonal to the central axis, that varies according to a defined function of the height of the head portion;
- a tail portion, opposite the head portion, the tail portion configured to be positioned at a non-flow path region of the shroud;
- and
- a shank portion that extends from the tail portion to the head portion, the shank portion having a height, extending along the central axis of the rub button, that is equal to a thickness of the shroud.
A method of determining a tip clearance between a plurality of rotor blades of a gas turbine engine and a shroud configured to circumscribe the plurality of rotor blades, the method comprising:
- positioning at least one rub button at the shroud, the at least one rub button comprising a head portion, a tail portion, and a shank portion, the head portion having a height configured to extend into a flow path region of the shroud along a central axis of the rub button that extends radially into the flow path region, the head portion comprising a plurality of known dimensions and a profile, orthogonal to the central axis, that varies according to a defined function of the height of the head portion, the tail portion opposite the head portion and configured to be positioned at a non-flow path region of the shroud, the shank portion extending from the tail portion to the head portion, the shank portion having a height, extending along the central axis of the rub button, that is equal to a thickness of the shroud;
- capturing an image of the head portion of the at least one rub button;
- measuring, from the image of the head portion, at least one dimension of the profile of the head portion to determine at least one image dimension of the profile of the head portion;
- and
- determining the tip clearance of the plurality of rotor blades based at least in part on:
- a correlation between the at least one image dimension of the profile and at least one of the known dimensions;
- and
- the defined function of the height of the head portion.
Dependencies are inferred from the claim text.