System for actuating an exhaust cowl

A gas turbine engine, comprising:

• a fan configured to create a fan flow;
• a compressor configured to compress gas;
• a combustor in fluid communication with the compressor;
• a turbine in fluid communication with the combustor, the turbine configured to drive the fan;
• an exhaust cowl that is adjustable and is configured to direct a main exhaust from the turbine;
• an outer cowl disposed outboard of the exhaust cowl, wherein an annular flow path is defined between the exhaust cowl and the outer cowl, wherein the outer cowl is configured to modulate an annular exhaust flow through the annular flow path;
• and
• a cowl actuation system coupled to the outer cowl and comprising:
• an actuator configured to modulate the outer cowl,
• a bell crank having a first end and a second end, the first end operatively coupled to the actuator and the second end operatively coupled to the outer cowl such that the bell crank is coupled in load transferring communication between the actuator and the outer cowl, the bell crank configured to pivot about a first point located between the first end and the second end, the first point located along a circumference, and
• a guide arm having a third end and a fourth end, the third end mounted to a second point and the fourth end operatively coupled to the outer cowl, wherein the guide arm is not directly coupled to the bell crank, wherein the second point is located along the circumference such that the first point and the second point are axially fixed and commonly aligned along the circumference, wherein the guide arm is not coupled in load transferring communication between the actuator and the outer cowl such that the guide arm pivots in response to movement of the outer cowl, wherein movement of the outer cowl is caused by load transfer from the actuator through the bell crank,
• wherein the outer cowl is configured to rotate circumferentially and translate axially.

A cowl actuation system, comprising:

• an outer cowl configured to modulate an annular exhaust flow of a gas turbine engine, wherein the outer cowl is disposed outboard of an exhaust cowl of the gas turbine engine, wherein an annular flow path is defined between the exhaust cowl and the outer cowl such that the outer cowl is configured to modulate the annular exhaust flow through the annular flow path, wherein the exhaust cowl is adjustable and is configured to direct a main exhaust from a turbine section of the gas turbine engine;
• an actuator;
• a bell crank having a first end and a second end, the first end operatively coupled to the actuator and the second end operatively coupled to the outer cowl such that the bell crank is coupled in load transferring communication between the actuator and the outer cowl, the bell crank configured to pivot about a first point located between the first end and the second end, the first point located along a circumference;
• and
• a guide arm having a third end and a fourth end, the third end mounted to a second point and the fourth end operatively coupled to the outer cowl, wherein the guide arm is not directly coupled to the bell crank, wherein the second point is located along the circumference such that the first point and the second point are axial fixed and commonly aligned along the circumference, wherein the guide arm is not coupled in load transferring communication between the actuator and the outer cowl such that the guide arm pivots in response to movement of the outer cowl, wherein movement of the outer cowl is caused by load transfer from the actuator through the bell crank.