| As key components in rotating machine, ball bearings have an important affect on dynamic performance of the entire mechanical system. It is a currently major study to really analyze the interactions of parts and the dynamic characteristics of the ball bearing. The main purpose of this article is, by finite element method to establish flexible multi-body dynamics model, which is multi-body and multi-degree of freedom, considering the dynamic contact relationship between the components of the ball bearings, to study the key issues of the ball bearing should be solved such as the dynamics of ball bearings and the cage stability and so on.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 mechanical characteristics of ball bearing have been studied by the limited element method, such as multi-body static contact characteristics, the vibration of cage, multi-body dynamic contact characteristics of ball bearing and so on. The dissertation is mainly categorized as follows:(1)Though analyzed the static multi-body contact characteristics of deep groove ball bearing by finite element method, the thesis has obtained the mechanical properties of the ball bearings under different load parameters. Hertz contact theory verified the mesh, contact parameters and contact pairs are correct and can be used to establish static and dynamics modeling of the ball bearings. At the same time, it verified the feasibility of the application of finite element method for analyzing the dynamics of ball bearings.(2)It has obtained the free vibration characteristics of cage though analyzing the free vibration of the ribbon and solid cage. It has also studied the form and characteristics of vibration of cage under centrifugal force by analyzed the prestressed modal of solid cage. Main conclusions:The vibration damage of ribbon cage occurs mainly at the rivet connections, and the solid cage occurs at the side girder and cross girder; cage modal frequency increases due to the effect of centrifugal force, and the impact is more pronounced for fatigue strength of cage under high-speed.(3)Considering the radial load, rotating speed, guide clearance and other factors, taking into account dynamic contact relationship between the ball, raceways and cage, it has established the flexible multi-body contact dynamics model of deep groove ball bearing and angular contact ball bearings. Then the dynamic contact simulation analysis has been done, and the dynamic characteristics of the ball bearing and the dynamic state of cage have been studied. Main conclusions:Varying flexible vibration response of odd-even alternately support has been showed under radial load; The stability of cage is relate with load, guide gap, speed and other relevant factors, the impact of speed mutation is the most serious.(4)The dynamic response testing of ball bearings was carried out. compared the simulation results and experimental results by picked up the radial vibration acceleration signal and vibration frequency signal of outer ring, the accuracy of the ball bearings flexible multi-body contact finite element model and simulation results has been verified.In summary, this paper has studied the load distribution of the ball bearings, the vibration of cage and the dynamic response of the ball bearings. By exploring the static and dynamic contact characteristics of ball bearings, it has a further understanding on the basic dynamics contact of ball bearings. It has important theoretical significance and value of engineering applications for design, manufacture, use and maintenance of ball bearings. |
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