高速电主轴热态性能分析与优化

发布时间：2018-01-04 14:48

本文关键词：高速电主轴热态性能分析与优化　出处：《华中科技大学》2011年硕士论文　论文类型：学位论文

【摘要】：电主轴技术是随着高速数控机床的发展和需求而发展起来的。高速电主轴的工作性能直接影响着机床加工系统的精度、稳定性以及应用范围,其动力学性能和热态特性对高速加工起着关键的作用。因此,需要对高速电主轴内部的发热和热传导机制进行分析和研究,确定能够准确计算电主轴温度分布的方法,为电主轴的结构设计提供有益的参考。本文首先确定电主轴内部主要热源和热传导方式,然后以传热学理论和滚动轴承分析理论为基础,分析得到热源发热、电主轴内外部对流换热和轴承接触热传导的计算方法,最后利用ANSYS软件,对电主轴进行稳态、瞬态热分析和热-结构耦合分析,并以主轴加工端热变形为目标函数进行优化。本文的具体工作如下: 通过分析电主轴的内部结构和运转特性,确定主要热源。以滚动轴承分析理论为基础,得到滚动轴承各类转矩和角速度的计算方法,从而计算轴承发热。通过计算异步电机的工作转矩和效率因子,得到确定电机运转发热的方法。然后通过分析轴承滚动体与轴承内外圈滚道的接触状态,确定计算滚动体与滚道之间接触热导的方法。最后基于传热学理论,分析得到计算电主轴各部分与冷却空气、环境空气、油气润滑混合物以及冷却水对流换热的方法。在通过以上步骤建立了描述电主轴发热及热传导的理论模型后,根据模型计算得到发热率、对流换热系数和接触热导率在不同转速下的数值,并作为载荷和边界条件加载至电主轴有限元模型上,对电主轴的加速和额定转速两种工作状态分别进行瞬态和稳态热分析,然后以稳态热分析的温度场结果作为载荷,对电主轴进行热-结构耦合分析,得到电主轴在额定转速下工作的热变形,最后以前后轴承与电主轴加工端的距离作为设计变量,以加工端热变形作为目标函数,进行优化求解,优化电主轴的结构。
[Abstract]:Electric spindle technology is developed with high speed CNC machine tool development and demand. The working performance of high-speed electric spindle directly affect the machining precision of the system, the stability and the scope of application, its dynamics and thermal characteristics plays a key role in high speed machining. Therefore, the need for internal heating and high speed electric spindle the heat conduction mechanism is analyzed and studied, can determine the accurate calculation method of spindle temperature distribution, provide a useful reference for the structural design of the spindle.
This paper first determines the main spindle internal heat source and heat conduction mode, and then to the theory of heat transfer and rolling bearing analysis theory, analysis of the heat generation, calculation method of main internal and external convection and heat conduction of the electrical contact bearings, finally using ANSYS software, the steady state of the electric spindle, coupled transient thermal analysis and structure analysis heat, and to optimize the thermal deformation of the spindle end as the objective function. The main results are summarized as follows:
Through the internal structure and operation characteristics analysis of spindle, determine the main heat source. Based on the rolling bearing analysis theory, calculation method of rolling bearing torque and angular velocity, we can calculate the bearing heating. Through the factor of work efficiency and torque calculation of asynchronous motor, get the method to determine the motor running hot. Then through the analysis of the contact state bearing rolling body and the bearing inner ring raceway, calculation method of contact thermal rolling. Finally, based on the theory of heat transfer analysis, calculated the spindle parts and cooling air, ambient air, lubricating oil and gas mixture and method of cooling water heat convection.
Through the above steps to establish a theoretical model describing the electric spindle heating and heat conduction, according to the heating rate calculation model, numerical heat transfer coefficient and thermal contact conductance at different speeds, and as the load and boundary conditions of loading to the electric spindle FEM model of the motorized spindle, the acceleration and the rated speed of two working conditions are analyzed in transient and steady-state thermal analysis results of temperature field, and then to steady heat as the load, analyze the thermal structure coupling of the electric spindle, get the spindle work at rated speed of thermal deformation, and finally to front and back bearing spindle for machining end distance as the design variables, to the end of the heat processing deformation as the objective function, optimization, structure optimization of spindle.

【学位授予单位】：华中科技大学
【学位级别】：硕士
【学位授予年份】：2011
【分类号】：TH133.2

【引证文献】