| Bearing-rotor system is a core component of most rotating machinery within roller bearings as support bearings, which is widely used in machinery, aerospace, chemical, national defense and other fields. As a support key parts, stability of roller bearings largely affect operation status of the entire system. Therefore, it’s a significant aspect of rotor dynamics study to research true roller bearing monomer internal dynamic characteristics during operation, analysis and evaluate dynamic performance of the entire roller bearings-rotor System, further.This project comes from the National Natural Science Fund project "The multi-body contact dynamics study of rolling bearing in mechanical system" (No.11002062) and the Talent Introduction Fund of Kunming University "flexible multi-body dynamics study of large rolling bearings" (No. KKSA20091026). The main purpose of this research is considering tapered roller bearings, roller bearings-rotor system as the research object, and then flexible multi-body contact models were established by the finite element method. Dynamics, with other issues of single roller bearing and roller bearing-system were explored in different conditions. The main research of dissertation is as follows:(1) By the finite element method, statics contact characteristics of single roller bearing and tapered roller bearings have been researched under radial load. The elastic deformation and contact stress, which have been well confirmed by theoretical solution. Simultaneously, it is well verified the correctness of finite element models, relevant parameter settings of contact pairs. On this basis, contact analysis of tapered roller bearing within different hollowness, which provided a theoretical basis for its optimal design.(2) Considering the dynamic contact relationship inside the components of tapered roller bearings, flexible multi-body contact analysis model has been established. Dynamic simulation analysis has been performed in case of light load and high speed, heavy load and low speed, in addition. The movement and mechanical properties of the various components in bearings have been analyzed. Compared with the theoretical results, it’s shown that force of roller is more stable in the condition of heavy load and low speed, but the cage speed fluctuated critically, which affected the stability of its movement a lot.(3) Roller bearing-rotor system of flexible multi-body contact analysis model, which has been established by FEM, its dynamic simulation analysis has been performed under 2 conditions, different speed and rotor imbalance. Compared with dynamics simulation results of single roller bearing, it is proved the validity and stability of the system model. For different parts in system, however, the movement and the mechanical properties are distinctive in these two working conditions, which illustrated the extent of the system in response to changing external conditions.(4) Through roller bearings-rotor system dynamic response experiment in the same conditions and Simulation Analysis, for the bearing supports, which have been extracted acceleration signal and 3-band vibration frequency of 4 measuring points within 2 positions. Compared with the finite element analyzed results, to some extent, it’s verified the correctness of the simulation model.In summary, the core study of this paper includes:statics multibody contact characteristics of single roller bearing, load distribution and dynamic response of roller bearing, dynamic response of the system and other issues of roller bearings-rotor system. By studying the statics and dynamics of roller bearings, dynamic contact characteristics of roller bearings-rotor system, and dynamic response test as well, a deep understanding of single roller bearing and bearings-rotor system dynamic response characteristics in rotating machinery have been raised. Consequently, this study provides engineering value for bearing-rotor system dynamics analysis. |
PDF Full Text Request