高速主轴系统热特性分析与实验

发布时间：2019-01-22 20:16

【摘要】：为了在设计阶段避免高速主轴在实际加工中由于温升过高可能会引起加工精度降低的问题,构建高速主轴的三维有限元模型(FEA)进行瞬态热-结构耦合分析.但传统热特性分析模型中,没有考虑结合面间接触热导致仿真精度较低,该有限元模型考虑接触热导对仿真结果的影响.利用Weierstrass-Mandelbrot函数表征轴承表面的粗糙形貌,利用功率谱法与粗糙表面形貌数据对分形参数进行辨识,并提出接触力学模型以计算用于接触热导建模的接触参数.最终,提出几何-力学-热综合预测模型计算结合面间的接触热导,有效避免统计学方法的不准确性与实验测量法通用性不强的缺陷.利用电机效率分析与轴承拟静力学分析法,分别求解电机与轴承热功率.由雷诺数判定流体的流动状态,并依据努塞尔数计算主轴部件的对流换热系数.将上述边界条件施加到该有限元模型对温度场与热变形进行仿真,并进行热特性实验验证该有限元模型的有效性.结果表明,该有限元模型的仿真精度明显优于不考虑接触热导的热特性分析模型.
[Abstract]:In order to avoid the problem that the high temperature rise of high speed spindle may lead to the reduction of machining precision in the design stage, the 3D finite element model (FEA) of high speed spindle is constructed and the transient thermal-structural coupling analysis is carried out. However, in the traditional thermal analysis model, the accuracy of the simulation is not considered because of the contact heat between surfaces, and the influence of the contact thermal conductivity on the simulation results is considered in the finite element model. The rough shape of bearing surface was characterized by Weierstrass-Mandelbrot function. The fractal parameters were identified by power spectrum method and rough surface topography data. The contact mechanics model was proposed to calculate the contact parameters used in contact thermal conductivity modeling. Finally, the geometric, mechanical and thermal comprehensive prediction model is proposed to calculate the contact thermal conductivity between surfaces, which effectively avoids the inaccuracy of statistical method and the lack of generality of the experimental measurement method. The thermal power of motor and bearing are calculated by means of efficiency analysis and quasi-statics analysis. The flow state of the fluid is determined by Reynolds number, and the convection heat transfer coefficient of the spindle is calculated according to the Nussel number. The above boundary conditions are applied to the finite element model to simulate the temperature field and thermal deformation, and the effectiveness of the finite element model is verified by the thermal characteristic experiment. The results show that the simulation accuracy of the finite element model is obviously better than that of the thermal characteristic analysis model without considering the contact thermal conductivity.
【作者单位】：西安交通大学机械制造系统工程国家重点实验室;
【基金】：国家“863”高科技研究计划资助项目(2012AA040701)
【分类号】：TG502

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