Novel Main Transmission Design Concepts

Rotary aircraft such as the V-22 tilt-rotor and H-53 helicopter use a transmission system to transfer power from the engines to the rotor system. Modern rotary-wing aircraft transmission systems can comprise up to 11% of an aircraft's empty weight. Thetransmission system gearboxes and rotor brake components are fabricated from relatively heavy metals that are subject to corrosion damage due to the harsh salt-water spray environment experienced by Navy aircraft. These metal housings are also expensiveto manufacture due to the nature of the metals used and the fabrication processes required to form the complexly shaped parts. Texas Research Institute Austin, Inc. proposes to develop cost effective, lightweight, damage tolerant polymer compositetransmission system component designs to replace currently used metallic components in the V-22 tilt-rotor aircraft. The use of composite materials will reduce the cost and weight of the transmission system while providing a reliable, corrosion freeservice life with little or no maintenance costs. The use of lighter weight, polymer composite transmission components will increase the power-to-weight ratio of the aircraft and allow for increased aircraft performance or payload. The proposed compositematerials will consist of high performance resin systems reinforced with high strength glass and/or carbon fibers. Successful development of lighter weight materials and designs for rotary-wing aircraft transmission systems components that can increase an aircraft's power-to-weight ratio and reduce maintenance costs by eliminating corrosion damage, while increasingdurability and reliability, will have immediate military applications in the V-22 tilt-rotor and H-53 helicopter programs. Additional commercial applications can be found in the commercial rotary-wing aircraft and automotive industries where lightweight,low cost, corrosion free transmission components would be desirable.