An Experimental Investigation on the Misalignment Effects in Journal Bearings

In this paper an investigation is made to evaluate the experimental performance of misaligned cylindrical and three-lobe journal bearings. A three-bearing double-disc rotor system with a test bearing in the middle and driven by a variable speed DC motor through an electromagnetic coupling is used. Various parameters which have been studied are friction through coastdown analysis, unbalance response and film thickness. The system damping also has been evaluated. The film thickness decreases, friction increases and system damping increases as the bearing misalignment increases. While the first, third and fourth harmonics vibration response is found to be almost steady with a increasing degree of misalignment, the second harmonics vibration response tends to decrease slightly. Presented as a Society of Tribologists and Lubrication Engineers paper at the ASME/STLE Tribology Conference in San Francisco, California, October 13-17, 1996