Engineering Services to Conduct Qualification Testing of Precision Forged Spiral Bevel Gears.

摘要

This report presents the results of a program to evaluate the relative surface-load capacity of CH-47C transmission spiral bevel gears manufactured by the integrally forged method (forged and ground) as compared to conventional current production gears (cut and ground). A three-phase test program was conducted. Phase I included the deflection test of one set of conventional baseline gears and rotating-load tests of two sets each of the integrally forged and conventional baseline gears. All gears were run at torque levels equivalent to 50,100, and 150 percent of the CH-47C single-engine rating. Phase II included rotating-load tests of two additional conventional basedline and five additional integrally forged gear sets in the Boeing Vertol test stand at loads of 100 to 130 percent of single-engine rating for 340 hours. Phase III involved extended surface-fatigue testing of four precision integrally forged gear sets in the test stand at 100 percent of single-engine rating for 800 hours. The results of this testing indicate that the surface-load capacity of the integrally forged gear sets is at least equivalent to that of the conventional baseline gears. (Author)