System and method of controlling tip clearance in a shroud assembly for a bladed disc
AssigneeRolls-Royce North American Technolgies Inc.
InventorRichard J. Skertic
Life of this patent
Estimating the term…
Abstract
An assembly in a turbine engine having a dynamically moveable flowpath boundary member for encasing a rotatable bladed disc and maintaining a clearance gap between the flowpath boundary member and the blade tips of the bladed disc. The assembly comprises a static casing, a flowpath boundary member carried by the casing, and a refrigeration system configured to remove heat from the flowpath boundary member to thereby thermally expand and contract the flowpath boundary member to control blade tip clearance.
Claims19
An assembly in a turbine engine having a dynamically moveable shroud segment for encasing a rotor segment comprising a bladed disc and maintaining a clearance gap between the shroud segment and a plurality of blade tips of the bladed disc, said assembly comprising:
- a static engine casing;
- a rotor segment comprising a bladed disc;
- a shroud segment carried by said casing, said shroud segment comprising a flowpath boundary member coupled to the static engine casing via a hanger, wherein the hanger and the flowpath boundary member are both moveable relative to the blade tips of the bladed disc by thermal expansion and contraction of said flowpath boundary member and the hanger;
- and
- an actuator for effecting thermal expansion and contraction of said flowpath boundary member, said actuator comprising a closed form refrigeration system having an evaporator, a compressor, a condenser, an expansion valve, and a refrigerant contained therein, wherein said evaporator is positioned in sufficient proximity to the hanger and said flowpath boundary member to extract heat from the hanger and said flowpath boundary member.
A system for maintaining a clearance gap between a shroud and a plurality of blade tips of a rotatable bladed disc in a turbine engine, said system comprising:
- a rotor segment comprising a bladed disc;
- a static casing encasing the bladed disc;
- a shroud segment carried by said casing, said shroud segment comprising a flowpath boundary member coupled to the static casing via a hanger, wherein the hanger and the flowpath boundary member are both moveable relative to the blade tips of the bladed disc;
- and
- an actuator comprising a closed form refrigeration system having an evaporator, a compressor, a condenser, an expansion valve, and a refrigerant contained therein, wherein operation of said closed form refrigeration system affects movement of the hanger and said flowpath boundary member relative to said blade tips.
In a turbine engine having a static casing and a rotatable bladed disc, a method of reducing blade tip rub comprising:
- providing a flowpath boundary member spaced radially inward from the casing to form a flowpath boundary around the bladed disc;
- thermally coupling the flowpath boundary member to a closed form refrigeration system via a hanger, the closed form refrigeration system having an evaporator, a compressor, a condenser, an expansion valve, and a refrigerant contained therein;
- and
- thermally expanding or contracting the hanger and the flowpath boundary member by removing heat via the closed form refrigeration system to affect movement of the hanger and the flowpath boundary member relative to a plurality of blade tips of the bladed disc.
Dependencies are inferred from the claim text.