Ref 2. HRT Statement of Research Effort (SORE).docx

Statement of Research Effort (SORE)

The Combat Capabilities Development Command (CCDC), Aviation and Missile Center (AvMC) is conducting research and development on technologies for a High- Reduction-Ratio Transmission (HRT) with or without variable output speed. The purpose of this effort is to mature and demonstrate to TRL 6 the technologies necessary for development, design, fabrication, and testing of a high reduction-ratio transmission in two stages or less. Input speed capability shall be greater than or equal to 30,000 RPM (constant) with a base output shaft speed reduction of 60:1. Continuously variable output shaft speed (based around the specified base output speed) is desirable but not required. Power density goals shall be 0.12 pound per horsepower (fixed output speed) or 0.15 pound per horsepower (variable output speed). The demonstration shall be based on a 200-500 horsepower system. Overall efficiency shall be 0.97 (97%) or better. Design life shall be no less than 4500 hours.

Corrosion of gearboxes and gearbox components as well as seal failures are two of the largest maintenance cost drivers for aircraft gearboxes. As part of this effort, advanced high-strength, corrosion resistant steels and new seal materials/designs shall be matured. The advanced high-strength, corrosion resistant steel shall have strength, surface hardness, core strength and ductility comparable to current aerospace gear steels, such as AISI 9310, as well as corrosion resistance equal to or better than AISI 440C. The new seal materials/designs shall be capable of operating at the input and output of the developed high reduction-ratio transmission, with a goal of less than 0.5cc/hour of oil leakage using DOD-PRF-85734S oil. Offeror shall include test methodology to be used under this effort to demonstrate new/advanced materials and design capabilities. The new corrosion resistant steels and new advanced seals shall be incorporated into the design and demonstrated to TRL 6 under this effort.

In order to understand the application of the proposed gearbox/transmission, the Offeror shall provide in their proposal a drive system concept using the HRT gearbox relative to a notional aircraft design, and identify the critical technologies to be developed under the program. The notional aircraft can be a rotary-wing aircraft or fixed-wing design. The HRT gearbox shall be capable of independently absorbing all torque, propeller/rotor, shear, and bending loads from the engine, propeller, or any combination thereof. Additional support structure, stiffeners, or dampers of any sort are discouraged. If required, these devices will count against and be included in the power density calculation.