大型精密重载静压工作台关键部件结构优化

发布时间：2018-04-05 09:16

本文选题：关键零部件　切入点：油垫　出处：《湖北工业大学》2017年硕士论文

【摘要】：为了满足高精、重载的加工要求,静压回转工作台的应用越来越广泛。提高静压回转工作台的刚性、回转精度、加工效率以及承载能力,对制造业有着巨大意义。本文通过对工作台的油垫、传动机构、台面等关键零部件以及静压供油系统进行优化研究,以提高工作台的加工精度。以扇形油垫为研究对象,对其进行静力学分析,得到油垫最大变形量远小于油膜厚度设计值;对其进行流场分析,发现油腔内有明显的涡流产生,严重影响油膜的承载能力。进而改变油腔的深度、形状,对比分析流场特性,发现狭窄油腔能明显减小涡流的产生,基于这一理论,将油垫的原扇形油腔改为日字形油腔,减少了涡流的产生,提高了油膜的承载能力。探讨静压工作台定量式供油和定压式供油的优缺点,设计出一种改进的恒流静压供油系统,以满足在不同载荷下,始终保持油膜厚度恒定的设计要求。通过对比分析回转工作台不同的传动机构,为减小传动链长度,提高传动精度,设计了使用蜗轮蜗杆的传动机构。针对蜗轮蜗杆副存在侧隙的情况,设计出一种消隙阻尼可自适应调整的双蜗轮蜗杆传动消隙机构,以保证回转工作台在工作时的平稳性和高精度。针对现有的工作台台面,对其进行静、动态特性分析,得到其承载能力和动态性能。基于工作台台面的静动态性能情况,以减轻其质量为目标函数,对其进行结构优化,优化后的结构满足工作时所需的动、静刚度要求,质量减轻3.8%。在宜昌长机科技组装车间,在已装配好的工作台上,利用试验模态分析装置,对优化后的工作台台面进行试验模态分析,将实验所得结果与仿真结果进行对比分析,证明采用有限元仿真的方法进行结构优化设计是可行的,模型的精度合理。
[Abstract]:In order to meet the requirements of high precision and heavy load processing, hydrostatic rotary table is more and more widely used.It is of great significance for manufacturing industry to improve the rigidity, precision, machining efficiency and bearing capacity of the hydrostatic rotary table.In this paper, the oil cushion, transmission mechanism, table surface and hydrostatic oil supply system of the worktable are optimized to improve the machining accuracy of the table.Taking the fan oil cushion as the research object, the maximum deformation of the oil cushion is far less than the design value of the oil film thickness, and the flow field analysis shows that there is obvious eddy current generation in the oil chamber, which seriously affects the bearing capacity of the oil film.Then the depth and shape of the oil chamber are changed, and the characteristics of the flow field are compared and analyzed. It is found that the narrow oil chamber can obviously reduce the eddy current generation. Based on this theory, the original fan oil cavity of the oil cushion is changed into the Japanese shape oil cavity, which reduces the eddy current generation.The bearing capacity of oil film is improved.This paper discusses the merits and demerits of the quantitative and constant pressure oil supply on the hydrostatic table, and designs an improved constant flow hydrostatic oil supply system to meet the design requirements of keeping the oil film thickness constant under different loads.In order to reduce the length of transmission chain and improve transmission precision, a transmission mechanism with worm gear and worm is designed by comparing and analyzing the different transmission mechanisms of rotary table.In order to ensure the stability and high accuracy of the rotary table, a kind of double worm drive clearance eliminating mechanism which can adjust the clearance damping adaptively is designed in view of the existence of side gap in the worm gear and worm gear pair of worm gear.The static and dynamic characteristics of the existing table are analyzed, and its bearing capacity and dynamic performance are obtained.Based on the static and dynamic performance of the table, the structure is optimized to reduce the mass of the table. The optimized structure meets the requirement of dynamic and static stiffness, and the mass is reduced by 3.8%.In Yichang long machine science and technology assembly workshop, the experimental modal analysis of the optimized table table is carried out by using the experimental modal analysis device on the assembled worktable, and the experimental results are compared with the simulation results.It is proved that the finite element simulation method is feasible and the precision of the model is reasonable.
【学位授予单位】：湖北工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG502.3

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