基于泊松比可控结构的高速主轴轴承预紧力自适应调节机理与方法研究

In order to keep good working performance of high-speed precision spindle in full rotation range, the online control of bearing preload is one of the key techniques. Aimed at the disadvantages of the existing preload adjusting equipments, such as complicated structure and poor controllability, a new adaptive adjustment method, based on the controllable Poisson’s ratio structure, is proposed. Firstly，by considering the fluid flow and temperature characteristics, a multi-field coupling analysis model is constructed for the high-speed spindle system, and the effect of preload on spindle rigidity, temperature rise and bearing life is analyzed. Based on the proposed model, the best preload force decision method is developed. Secondly, a thermal mechanical coupling analysis model is developed for the controllable Poisson’s ratio structure and the shape-property controllable design method is developed. By breaking through the limitation of two-dimensional structure, a three-dimensional bearing spacer of controllable Poisson’s ratio structure is designed and implemented inside the spindle system. A comprehensive analysis model, combining the spacer and the spindle, is presented, and the deformation property and the rigidity of the spacer are investigated. A new preload adaptive adjustment method, based on the spacer of Poisson’s ratio controllable structure, is finally promoted. The proposed theoretical models and the adaptive preload adjustment method are experimentally validated via the developed inner ring temperature monitoring technology and the preload force online testing method. The research will promote the development of the high-speed spindle and therefore the advanced CNC machine tools of our country. The theoretical results will benefit the property analysis and the design of the controllable Poisson’s ratio structure.

预紧力在线调控是保障高速精密主轴全速段最佳工作性能的核心技术。针对现有轴承预紧力调控装置结构复杂可控性差的问题，提出一种基于泊松比可控结构的预紧力自适应调节方法。构建考虑流场、温度场的主轴多场耦合模型，研究预紧力对主轴刚度、温升、寿命的影响机理，提出不同转速工况的最佳预紧力确定方法。构建泊松比可控结构热力耦合模型，研究其性能形成机理及控形控性设计技术。突破传统二维结构限制，研究三维泊松比可控结构隔套的设计实现方法；构建可控结构隔套-主轴联合分析模型，研究温度及离心力下泊松比可控结构隔套的预紧力调节机理，研究满足全速段最佳预紧力控制要求的隔套结构优化方法。研究针对高速主轴的轴承内圈在线测温及预紧力在线测试实验技术，实验验证基于泊松比可控结构隔套的预紧力调节技术及方法的有效性。项目工作对实现高档数控机床核心部件国产化具有重要意义，理论成果为泊松比可控结构的分析和设计提供模型和方法。

预紧力在线调控是保障高速精密主轴全速段最佳工作性能的核心技术。针对现有轴承预紧力调控装置结构、复杂可控性差的问题，本项目提出和研究了一种基于泊松比可控结构的预紧力自适应调节方法。项目首先明确预紧力的调控要求，考虑设计工作状态下轴承受装配、载荷、温度、转速等多种因素影响，构建了考虑装配应力、温度场、离心力等的主轴预紧力多场耦合分析模型，研究了预紧力对主轴刚度、温升、寿命的影响机理，提出了不同转速工况条件下最佳预紧力确定方法；其次开展了单胞结构的选择、三维泊松比可控隔套热力耦合分析模型构建、隔套性能分析及优化设计方法等研究，明晰了三维泊松比可控隔套力、变形、刚度的形成机理，为负泊松比隔套的优化设计及应用提供理论与技术支撑；然后通过构建可控结构隔套与轴承主轴联合分析模型，研究了温度、离心力及轴承轴向约束条件下泊松比可控结构隔套的预紧力调节机理，提出了满足全速段最佳预紧力控制要求的隔套结构优化方法。最后针对实验验证需求，改进了高速主轴的轴承内圈在线测温及预紧力在线测试实验技术，搭建了实验台，实验验证基于泊松比可控结构隔套的预紧力调节技术及方法的有效性。本项目初步形成了考虑实际工况的轴承热力耦合分析模型、最佳预紧力确定方法，以及针对三维负泊松比材料的热力耦合分析模型，为泊松比可控结构的分析和设计提供了模型和方法。同时项目改进了轴承旋转部件测温技术及预紧力在线测试技术，为轴承性能的实验测试提供了新的途径。