Development of Advanced Lift Fan Clutch

The overall objective of the program is to develop innovative concepts for more efficient and reliable clutch plates for the JSF Fan Duct Clutch. Carbon-carbon composite clutch plates can meet a 1,500 engagement life requirement for a lift fan clutch, but this is at least two times less than the desired lifetime. The carbon-carbon composite also does not consistently provide the desired range of friction coefficients. A new, innovative clutch plate concept that reduces wear rate and higher overall friction coefficient is required to increase the service life of the clutch. The clutch engages at up to ~8500 rpm and the clutch plates must survive rotational speeds in excess of 10,000 rpm. The clutch plates are required to withstand a high shear load in transferring ~70,000 in-lb of torque. The required instantaneous dynamic friction coefficient is>0.1 with a desired mean static coefficient of ~0.2. In Phase I Allcomp proposes to evaluate and demonstrate the feasibility of innovative clutch material and design to provide long wear life and a high, stable friction coefficient. New classes of C-C and CMC composite materials will be developed aiming to achieve balanced structural, thermal and frictional performances for the JSF Fan Clutch application.