Gas turbine engine blade tip clearance apparatus and method

A gas turbine engine compressor, comprising:

• one or more rotor assemblies, each rotor assembly having a plurality of blades with each blade having a blade tip;
• a shroud having one or more blade seal surfaces disposed radially outside of the one or more rotor assemblies;
• wherein the blade tips in each of the one or more rotor assemblies has a mating conical geometry with at least one of the one or more blade seal surfaces, and a clearance distance extending between the blade tips and blade seal surfaces;
• and
• an actuator selectively operable to axially move the one or more rotor assemblies relative to the shroud to alter the clearance distance.

A gas turbine engine compressor, comprising:

• one or more rotor assemblies, each rotor assembly having a plurality of blades with each blade having a blade tip;
• a shroud having one or more blade seal surfaces disposed radially outside of the one or more rotor assemblies;
• wherein the blade tips in each of the one or more rotor assemblies has a mating conical geometry with at least one of the one or more blade seal surfaces, and a clearance distance extending between the blade tips and blade seal surfaces;
• and
• means for selectively axially moving the one or more rotor assemblies relative to the shroud to alter the clearance distance.

A gas turbine compressor, comprising:

• a rotor assembly having a plurality of blades with each blade having a blade tip;
• a stator assembly disposed adjacent the rotor assembly;
• a knife-edge seal having a knife-edge portion attached to the rotor assembly and an abradable pad attached to the stator assembly, wherein the abradable pad includes a preformed channel that provides different seal gaps at different relative axial positions of the knife-edge portion and the abradable pad;
• an actuator selectively operable to axially move the rotor assembly relative to the stator assembly to alter the seal gap.

A method for controlling blade tip clearance within a gas turbine compressor, comprising the steps of:

• providing a compressor having one or more rotor assemblies, each rotor assembly having a plurality of blades with each blade having a blade tip, and a shroud having one or more blade seal surfaces disposed radially outside of the one or more rotor assemblies, wherein the blade tips in each of the one or more rotor assemblies has a mating conical geometry with at least one of the one or more blade seal surfaces, and a clearance distance extending between the blade tips and blade seal surfaces;
• providing an actuator selectively operable to axially move the one or more rotor assemblies relative to the shroud;
• and
• axially moving the one or more rotor assemblies relative to the shroud using the actuator to alter the clearance distance.

A method for controlling knife-edge seal gap within a gas turbine engine, comprising the steps of:

• providing at least one rotor assembly having a plurality of blades with each blade having a blade tip, and stator assembly disposed adjacent the at least one rotor assembly;
• providing at least one knife-edge seal having a knife-edge portion attached to the at least one rotor assembly and an abradable pad attached to the stator assembly, wherein each abradable pad includes a preformed channel that provides different seal gaps at different relative axial positions of the knife edge portion and the abradable pad;
• providing an actuator selectively operable to axially move the at least one rotor assembly relative to the stator assembly;
• and
• axially moving the at least one rotor assembly relative to the stator assembly using the actuator to alter the seal gap.

A gas turbine engine, comprising:

• one or more rotor assemblies, each rotor assembly having a plurality of blades with each blade having a blade tip;
• one or more shroud segments having blade seal surfaces disposed radially outside of the one or more rotor assemblies;
• wherein the blade tips and blade seal surfaces have mating conical geometries and a clearance distance extending between the blade tips and blade seal surfaces;
• and
• an actuator selectively operable to axially move one or both of the shroud segments and rotor assemblies relative to the other of the shroud segments and rotor assemblies to alter the clearance distance.