纳米精度油静压主轴的精化规律研究

Oil hydrostatic spindles are key components in ultra-precision grinding machines.At present, the rotation accuracy of that can realise up to 0.1μm, and in order to make it reach nanometer level, the accuracy increasing rule should be researched further more. This project aims to the accuracy increasing rule between the geometric accuracy of the guide surfaces and the rotation accuracy of the spindle, based on which the oil hydrostatic bearing design is expected to be optimized, and the oil hydrostatic spindle with a rotation accuracy of 0.03μm is expeceted to be developed. The main contents of the project include: the form errors of guide surfaces in the radial bearing and axial bearing are analyzed, the static and dynamic model of the rotor are built respectively, then the relationship among the form errors and the rotation errors are solved, in addition, the influences of the positon errors on the rotation errors are studied. In other hand, the influences of the structural deformation on the rotation errors are studied by a solid-liquid coupled analysis. Further more, a multi-objective optimization design method on the oil hydorstatic bearing is put forward, based on that a software is developed. The rotation accuracy is set to be three levels of 0.5μm, 0.1μm and 0.03μm, three experimental setups are built successively to make the rotation accuracy improve step by step and realise the final research object of the project.

油静压主轴是超精密铣磨机床中的关键部件，目前，其回转精度的先进水平可达0.1μm，要进一步达到纳米量级，则需对其精化规律进行深入研究。本项目旨在通过研究油静压轴承中各导向面几何精度与主轴回转精度间的精化规律及其影响因素，实现对油静压轴承的优化设计，并最终研制出回转精度达0.03μm的油静压主轴。主要研究内容有：分析径向和推力轴承中各导向面的形位误差，建立转子的静力学和动力学模型，求解各导向面自身形状误差与对应主轴回转误差之间的映射关系，并研究其相互间位置误差对主轴回转误差的影响规律，同时，采用流固耦合分析方法研究结构变形对主轴回转误差的影响规律；进而，基于油静压主轴的精化规律和结构变形的影响规律，提出一种多目标优化设计方法，并开发具有通用性的优化设计软件；将回转精度划分为0.5μm、0.1μm和0.03μm三个精度等级，依次搭建试验平台，使回转精度实现逐代递增，并最终实现本项目的研究目标。

为了进一步提高油静压轴承的回转精度，需要深入研究轴承几何精度到主轴回转精度的精化规律。本项目通过研究静压支承的动静特性和运动误差，求解了各导向面自身形状误差与对应主轴回转误差之间的映射关系，并研究其相互位置误差对主轴回转误差的影响规律。同时以动态雷诺方程和导轨的弹性变形方程为基础，结合导轨工作台动力平衡方程，建立静压导轨的流固耦合模型，分析了流固耦合对静压导轨压板变形量、动静刚度以及阶跃响应的影响，为实现对静压支承的优化设计提供理论依据。进一步研究了主动静压轴承技术，进而提高超精密机床的稳定性及加工精度，为超高精度静压轴承实际应用奠定了理论基础。