Test Results Report and Technology Development Report, HLH/ATC Drive System Aft Rotor Shaft Bearing Test

The report presents the results of a program to define criteria and to design, fabricate, and test simulated HLH aft rotor shaft tapered roller bearings. Tests were performed in a back-to-back test rig which simulated the expected loading, lubrication, housing stiffness, and preload of the HLH aft rotor shaft application. Technical test inspection and evaluation were used to determine bearing performance and adequacy of bearing fatigue life under predicted operating conditions. Trade studies conducted of the HLH aft rotor shaft support bearing show that large-pitch-diameter and high-contact-angle duplex tapered roller bearings provide the most effective method of reacting the HLH rotor loads. This bearing configuration resulted in the lightest weight and most compact bearing system for the HLH aft rotor shaft bearing application.