并联机构转动副滚动轴承静刚度参数辨识

以新型五自由度完全并联机构的一组滚动轴承支撑单元为研究对象,利用多体系统传递矩阵法、有限元法及实验法深入研究其静刚度预估问题,提出一种滚动轴承的静刚度参数辨识流程/方法.首先,将滚动轴承支撑单元等效为多柔体系统,借助传递矩阵法建立其静刚度参数与结构模态参数间的映射关系;其次,借助实验模态分析法确定滚动轴承支撑单元的固有特性,通过比对系统固有频率和振型,确定滚动轴承支撑单元的静刚度参数;最后,将辨识出的静刚度参数代入滚动轴承支撑单元有限元分析模型,将仿真结果与实验结果相比较,以验证静刚度辨识方法的有效性.研究表明,这种滚动轴承静刚度参数辨识方法精度较高,为含转动副并/混联构型装备的静刚度优化设计提供了理论依据.

Static Stiffness Parameter Identification of Rolling Bearings in Parallel Mechanisms with Revolute Joints

A static stiffness parameters identification process/method of rolling bearings was proposed, with a set of revolute joints of a novel parallel mechanism with 5 degrees of freedom as the research object and the methods of multi-body system transfer matrix, finite element and experiment to study its static stiffness estimation. Firstly, the rolling bearing assembly was perceived as a flexible multi-body system and transfer matrix method （TMM）was utilized to establish the mapping relationship between its static stiffness parameters and the modal parameters of the system. An experimental modal analysis （EMA） of the roiling bearing assembly was then carried out to identify its inher- ent characteristics. The static stiffness parameters of the rolling bearing assembly were determined by comparison be- tween the inherent frequencies and modes of the system in EMA and those in TMM. Finally, the static stiffness pa- rameters obtained were applied to a finite element analysis model of the rolling bearing assembly and the simulation results were compared with the experimental results to verify the effectiveness of the proposed static stiffness identification method. It is proved that the proposed static stiffness parameter identification method for rolling bearings is precise and provides the theoretical basis for static stiffness optimization of parallel mechanisms with revolute joints.