High-cycle, short range-of-motion linkage apparatus for gas turbine engine applications

A high-cycle, short range-of-motion linkage apparatus for actuation of a turbofan engine component linkage assembly, the linkage apparatus comprising:

• a pivot member having a head portion and a stem extending therefrom;
• an actuator moveable between at least a first position and a second position and having a first end and a second end, the actuator first end defining a receiving portion into which the stem is removably secured, the actuator second end defining a coupling member moveable between at least a first position and a second position respectively corresponding to the actuator first and second positions;
• a spherical plain bearing secured within the head portion of the pivot member and operable within an operating temperature range of about 260° C. (500° F.) to about 315° C. (600° F.), the spherical plain bearing comprising,
• an inner member having an outer engagement surface and a first bore extending at least partway therethrough,
• an outer member swaged around the inner member, the outer member disposed between the inner member and the head portion of the pivot member, the outer member having an inner engagement surface contoured to a shape complementary to the outer engagement surface of the inner member,
• a liner comprising polytetrafluoroethylene and a polyimide resin reinforced with aramid fibers having an operating temperature range of about 260° C. (500° F.) to about 315° C. (600° F.) and disposed between the inner engagement surface of the outer member and the outer engagement surface of the inner member, and
• the spherical plain bearing outer member having a range of motion in relation to the spherical plain bearing inner member in the range of up to 90°;
• and
• a first shaft extending into the first bore and at least one corresponding aperture in the turbofan engine component linkage assembly and pivotally connecting the actuator first end to the turbofan engine component linkage assembly;
• and
• a second shaft extending into a second bore defined in the coupling member and at least one corresponding aperture in a turbofan engine structural member linkage assembly and pivotally connecting the coupling member to the turbofan engine structural member linkage assembly.