SBIR-STTR Award

Power transmission couplings which accommodate axial, bending and, - in pairs - transverse displacements, must y carrying relatively large torsional loads. It is also required for some installations that torsional stiffness be prescribed such as avoid system instabilities.Attributes of a coupling which would be perceived as advantageous would be lack of maintenance requirements; long service life via absence of moving parts and consequential wearnoise generation and attenuation of upstreamdriveline noise and vibration; and inherent torque density (large torque in a small envelope). It has also been recognized that if the flexible of a single filament wound composite structure, the low 'part t' might translate into a competitive selling price. Niche applications like helicopter driveshafts typically fic performance from each axis. A newly patented composite coupling concept is proposed .

Power transmission couplings which accommodate axial and angular motion must do so while simultaneously carrying relatively large torsional loads. Attributes would be lack of maintenance requirements; long service life; attenuation of vibration; inherent torque density, and low cost. Niche applications like helicopter driveshafts require outstanding specific performance from each axis. A new concept is proposed here following phase I SBIR NAWC-AD feasibility which overcomes previous composite limitations yet retains the benefits of corrosion resistance, high speed operation, and achieves all the above listed attributes. Benchmark data on V22 tilt-rotor couplings are tabulated along with estimated performance of the new concept. Analytical models were extended during phase I; 6 inch couplings successfully manufactured; and a high degree of confidence developed in the suitability of this concept for scale up. Difficulties were encountered with CNC control of the five axis filament winder during phaseI, given the complex (hyperbolic) initial geometry in a small envelope. These were overcome and all sizes from 3 inch diameter to 30 inch appear to be producable with reasonable cost. Greatest promise is shown by wound stainless steel filaments left unwetted in the diaphragm region and anchored by a rigid central hoop wind. This permutation avoids compression and shear in critical regions and promises to provide long fatigue life at high torque.