Commissioning of a high speed rolling-element bearing rig: Preliminary results

Rolling element bearings represent critical components in rotating machinery especially aircraft engines and accessory gearboxes. They are required to operate reliably under high temperature and speed conditions well over 3 million DN (bearing bore in millimeter x shaft speed in rpm) where hybrid technology is being investigated by numerous engine manufacturers. As a result, there has been an enormous amount of work done in the field over the last five decades where different test rigs have been built for that purpose. For instance, Holmes [1] tested ball bearings with a 125 mm bore at speeds up to 24 krpm (3.0 MDN) to determine skidding characteristics. Similarly, in their experimental work, Bamberger et al. [2] studied the effect of speed and load on the performance operation of a 120 mm bore angular contact ball bearing. They found that significant skidding occurred at the highest speed of 25 krpm. This paper describes the operation of a high-speed bearing rig instrumented with state-of-the-art sensors to study performance characteristics of rolling-element bearings operating at extreme conditions. A typical aircraft engine roller bearing was used during the commissioning phase of the rig. Preliminary results of the main bearing characteristics under controlled operating conditions are presented.