Patent ID: 8915465
Filing Date: 2014-12-23
Classification: B64C,F01M

Abstract:
1. A rotor system for a rotary wing aircraft the rotor system comprising: a mast secured to an airframe; a rotor hub rotatably mounted to the mast; a bearing interposed between the mast and hub, the bearing comprising rolling elements; a feed oil line and a return oil line in fluid communication with the bearing; and a pump positioned to move a fluid in a closed fluid path between the feed oil line and return oil line a thermal modulator positioned in thermal contact with fluid within the closed fluid path; at least one valve within the closed fluid path; and a control system operably coupled to the valve and thermal modulator and configured to activate one or both of the pump and thermal modulator; the bearing, wherein the rolling elements have a preloaded condition within an operating temperature range; and the control system, further programmed to activate the thermal modulator to be effective to maintain the preloaded condition of the rolling elements.