Abstract
During the service life of bearings in ship systems, they operate under discrete constant operating conditions involving load levels, rotational speeds, and ambient vibrations. Traditional research mostly relies on idealized laboratory conditions of single constant load and constant speed, leading to significant discrepancies between the derived performance degradation patterns and actual on-site scenarios of marine bearings. In view of this, this study integrates the maximum entropy method (MEM) and Poisson counting principle (PCP) to analyze the variation law of the bearing performance degradation parameter—degradation probability—with changes in load ratio and rotational speed. Temperature gradients and impact vibrations are excluded to align with the actual experimental scope. The research results show that (1) the degradation probability of the optimal vibration performance state of the test bearings exhibits an overall nonlinear increasing trend during operation. (2) For the same time series, the degradation probability increases with the rise in load ratio and enters the non-zero phase earlier (indicating earlier degradation initiation). (3) Except for the 3rd–6th time series at 6000 r/min, the degradation probability within the same time series decreases with increasing rotational speed under discrete constant speed conditions.