In order to study the influence of torque load on the lubrication and wear of the sliding bearing of the rigid rotor system, the theoretical and experimental researches on the single-span rotor system with low speed were carried out. A special force sensor was used to measure the bearing load under different torque excitations, and the oil film pressure was calculated. The oil film pressure and thickness of sliding bearing under low speed (210r/min) were simulated by combining the lubrication theory. Based on the film thickness ratio theory, the corresponding relationship between the lubrication state and the torque load value was deduced. In addition, the wear rate and abrasive grain morphology of sliding bearing with different torque values were analyzed by means of oil sample preparation to verify this correspondence. The results show that the film thickness ratio has a logarithmic function relationship with the constant torque load, and the film thickness ratio curve can be used to determine the corresponding torque values under different lubrication states. The wear rate under mixed lubrication state increases exponentially with the torque load, and the main wear mechanism is adhesive wear and abrasive wear. The research results have certain guiding significance to the adjustment of the actual running condition of sliding bearing and its life prediction.

In the rotor system subjected to torque, the lubrication state of the journal bearings will change, which can lead to wear life change of such bearings. Therefore, the experimental study on the wear life prediction of the journal bearings in the rotor system subjected to torque was carried out. An improved Archard model for wear rate prediction was proposed, which can be applied to determine the relationship among speed, torque, and wear of different bearings. The 20 h wear of a single-span rotor system was tested at three speeds and torque. Test results show that the impact of torque on wear is greater than that of speed. The wear life of a bearing can be predicted with determined wear threshold. The 20 h wear was calculated by using the wear data of the rotor test bench in this model and compared with the actual wear. The comparison results indicate that the accuracy is higher than 92%. The torque – wear life curve shows that wear life is logarithmic to torque at a constant speed and significantly affected by changes in the low torque. Given a constant torque, the wear life will decrease logarithmically with the speed increasing.