Composite Gear Housing - Aerospace

Aerospace

Composite gear transmission housing for aerospace is in development stage under the Advanced Rotorcraft Transmission program. ART program is a joint Army/NASA program to develop and demonstrate lightweight, quiet, durable drivetrain systems for next generation rotorcraft. Sikorskiy Aircraft and Boeing participate in ART program.(NASA –TM -103276 published report CSCL 13T, Technical memorandum 103276). By NASA report, Sikorskiy applied composite material for CH-53E helicopter gear housing, load truss, and main rotor quill shaft. “Major weight saving can be realized through the application of composite structural material. The ACA transmission design of Sikorsky Aircraft is particularly amenable to incorporation of composites because of geometric simplicity of the housing. It is estimated that application of lightweight composites to the gear transmission results in 700 to 800 lb weight reduction compare to baseline materials.” Sikorsky aircraft has widely advertised its progress on developing of composite gear housing for aerospace application. On June 24–26, 1991, in Sacramento, CA, Sikorsky Aircraft has presented a photograph of its composite gear housing. Sikorsky used graphite-epoxy material for manufacturing of composite gear housing. The composite gear housing was manufactured with bearing interfaces identical to the original steel housing; sic “therefore the internal components will fit into the housing.” In 1992 NASA continued advertising composite materials for use in aviation gear mechanical systems. During the AIAA/SEA/ASME/ASEE conference in Nashville, TN, July 6–8, 1992, NASA published a picture describing one of proposed design embodiment of composite gear housing for an aircraft. In its permanent effort to promote use of lightweight composite materials on aircraft NASA has solicited a contract for development of 21st century rotorcraft gear drive system commonly known as RDS-21 (Rotorcraft Drive System 21) The program is directed by the U.S. Army Applied Aviation Technology Directorate (AATD) Boeing was awarded to participate in this program. While the face gears are the big portion of this program, fiber reinforced composite materials will be used as well. As it stated in a joint NASA-Boeing publication the new aircraft gearbox will incorporate composite shafting and structural housing.