摘要
在现有的精密机床中,空气静压导轨平台存在阻尼突变、载荷不高的问题,基于磁流体轴承,提出了一种大载荷磁流体二维导轨平台。首先,对基于磁流体的导轨平台关键问题进行了研究,包括空气损耗问题和磁流体尾迹问题;然后,采用磁流体压力轴承设计了一个双U形导轨平台结构,并将顶部、底部和侧部轴承垫紧密地放置在一起,从而在动子上形成了一个储液层;采用上下磁化配置的导轨平台具有6个轴承垫,每个轴承垫由多个小型磁体组成;其次,对载荷能力、刚度和涡流阻尼进行了数值模拟;最后,选用了煤油基磁液、铝材和铁素体不锈钢制备了一台平台样机,进行了平台的性能测试,对该导轨平台的有效性进行了验证。研究结果表明:该平台的平面度为±7μm,具有较高的可重复性,明显优于现有基于磁流体轴承的精密运动系统;在相同行程和尺寸条件下,与气动平台相比,该平台的最大有效载荷为140 N,提高了40%;阻尼在2 N·s/m至4 N·s/m之间相对恒定,且可预测,解决了气动平台的阻尼突变问题,有利于实现导轨平台高精度定位的目的。
Aiming at the problems of sudden damping change and low load of aerostatic guide platform in precision machine tools,a large-load magneto fluid two-dimensional guideway platform was proposed based on magnetic fluid bearings.Firstly,the key problems of guideway platform based on magnetic fluid were studied,including air loss and magnetic fluid wake.Secondly,a double U-shaped guideway platform structure was designed by using magnetic fluid pressure bearings,and a liquid storage layer was formed on the rotor by placing the top,bottom and side bearing pads closely together.The guideway platform with upper and lower magnetization configuration had six bearing pads,and each bearing pad was composed of a plurality of small magnets.Then,the load capacity,stiffness and eddy current damping were numerically simulated.Finally,kerosene-based magnetic fluid,aluminum material and ferritic stainless steel were selected to prepare the platform prototype,and the performance was tested,and the validity of the guideway platform was verified.The results show that the flatness of the platform is±7μm,which has high repeatability and is obviously superior to the existing precision motion system based on magnetic fluid bearings.Under the same stroke and size,compared with the pneumatic platform,the maximum effective load is 140 N,which is increased by 40%.The damping is relatively constant and predictable between 2 N·s/m and 4 N·s/m,which avoids the sudden change of damping of the pneumatic platform and is beneficial to realize high-precision positioning.
作者
杨辉
张玉华
YANG Hui;ZHANG Yuhua(School of Automotive and Mechanical and Electrical Engineering,Zhoukou Vocational and Technical College,Zhoukou 466000,China;School of Mechanical Engineering,Zhengzhou University of Science and Technology,Zhengzhou 450064,China)
出处
《机电工程》
CAS
北大核心
2024年第3期475-481,共7页
Journal of Mechanical & Electrical Engineering
基金
河南省科技发展计划基金资助项目(182107000062)。
关键词
精密加工
磁流体导轨平台
空气静压导轨平台
阻尼突变
大载荷
平面度
可重复性
precision machining
magnetic fluid guideway platform
aerostatic guideway platform
sudden damping change
large load
planeness
repeatability
