高速精密轧辊磨头的热力学特性及动态性能研究

Facing at the actual situation of depending on import for high speed and precision roll grinder in our country at present, it has important theoretical value and practical significance for realizing the nationalization of high speed and precision roll grinder that studying thermodynamic characteristics and dynamic performances of 80m/s high speed and precision roll grinding head in this project. Oil film lubrication mechanism of 80m/s high speed and precision roll grinding head will be firstly studied in this project, and thermodynamic and dynamic parameters of each friction pair of oil film lubrication will be extracted. On the basis, thermodynamic characteristics and dynamic performances of the grinding head will be studied respectively. For thermodynamic characteristics, the thermal stress field and thermal deformation of the grinding head caused by each heat source and the coupling thermal stress field and thermal deformation of the grinding head caused by all heat sources will be calculated and analyzed, and the weak link of thermal deformation of the grinding head will be identified. For dynamic performances, the low-order natural frequency, vibration mode and anti-vibration performance under dynamic excitation of the grinding head will be revealed from the angles of modal analysis and harmonic response analysis, and the weak link of dynamic performance of the grinding head will be identified. Finally, in order to design a kind of grinding head whose thermal and dynamic performances are both good, the optimization design for the grinding head will be performed from two aspects of thermal characteristic and dynamic performance. Some original theoretical achievements will be obtained in this project, and theoretical materials and technology supports can be provided for developing domestic 80m/s high speed and precision roll grinder.

针对我国目前对高速精密轧辊磨床依赖进口的实际情况，本项目开展80m/s高速精密轧辊磨头的热力学特性及动态性能的研究对实现高速精密轧辊磨床的国产化具有重要的理论价值和现实意义。本项目首先对80m/s高速精密轧辊磨头的油膜润滑机理开展研究，拟提取各油膜润滑摩擦副的热力学和动力学性能参数，在此基础上，分别开展磨头热力学特性及动态性能的研究。针对热力学特性，拟计算与分析各热源引起磨头的热应力场和热变形以及各热源共同作用下磨头的耦合热应力场和热变形，并识别出磨头热变形的薄弱环节；针对动态性能，拟从模态分析和谐响应分析的角度揭示磨头低阶固有频率和振型以及在动态激励下的抗振性能，并识别出磨头动态性能的薄弱环节。最后，为了设计出一种热态和动态性能均优良的磨头，对磨头在热态和动态性能两方面进行优化设计。本项目将形成原创性的理论成果，能为国产80m/s高速精密轧辊磨床的开发提供理论资料和技术支持。

本项目针对我国目前对高速精密轧辊磨床依赖进口的现实，开展高速精密轧辊磨头的热力学特性及动态性能的研究对促进80m/s高速精密轧辊磨头的国产化具有重要的意义。本项目的主要研究内容包括高速精密轧辊磨头的油膜润滑机理研究、热力学特性研究、动态性能研究及其优化设计四个方面，围绕此四个方面的研究内容，本项目取得如下研究成果：（1）对80m/s高速精密轧辊磨头的带轮机构、卸荷装置、动静压轴承、辊形轮廓曲线生成机构、主轴以及止推轴承等核心部件进行了设计，在此基础上，最后设计出了一种80m/s高速精密轧辊磨头的整体结构。（2）揭示出了所设计的80m/s高速精密轧辊磨头的基本性能，包括油膜润滑性能、热力学性能以及动态性能，研究结果表明磨头各油膜润滑副的压力场和温度场分布性能良好，但磨头整体结构上出现了局部温度偏高、局部热变形偏大、局部模态性能和谐响应性能不佳的情况，需对磨头进行优化设计。（3）提出了80m/s高速精密轧辊磨头的优化方法并对其关键部件进行了优化设计，优化后，各关键部件的结构更为紧凑，且止推轴承的摩擦功耗减少了74.6%；动静压轴承的摩擦功耗减少了22.6%，带轮的中心距减小了10%；在此基础上，再次对磨头的热力学性能和动态性能进行了研究，结果表明：优化后，磨头的热力学特性和动态性能均得到明显的提高，其中，最大温升下降了17℃，最大变形减少了33um，前五阶固有频率最高增大了26.7%，最大谐响应变形值减少了81%。（4）形成了80m/s高速精密轧辊磨头性能测试实验平台的研制技术，为其性能测试奠定了基础。本项目的研究成果能为国产80m/s高速精密轧辊磨床的研发提供理论资料和技术支持。