Abstract: | The requirements of very high performance (stress, rotational speed, stability to vibrations, etc.) for the compounds of mechanical engineering also involve an adequate fiability. The bearings can run at over 70 m/s peripheral speed of high fiability conditions (gas turbines in the aviation industry), with some high precessions and depressed frictions (gyroscopes, grinding broaches), with low/depressed noise and vibrations level. The increase of the bearings speed over the limits considered âordinaryâ influences negatively the durability due to some kinematic, dynamic and lubrication significant changes. Major centrifugal forces appear, friction forces modify sensitively, starvation phenomenon occurs, and vibrations are established, too. |