【作者】 解志杰；

【导师】 宋宝玉；

【作者基本信息】 哈尔滨工业大学 ， 机械设计及理论， 2009， 硕士

【摘要】 当前科学技术的突飞猛进,对一些装置的轴系提出了更高的精度要求。超精密回转轴系的研究水平,关系到宇航技术、精密机床和精密仪器仪表业的发展,是一个国家工业和军事技术的综合体现。能胜任构成精密轴系的轴承,首推气体轴承和磁轴承两类。但这两种轴承都存在着一定的缺陷,如气体轴承不易控制;磁浮轴承承载能力低等。本文提出了一种结构紧凑、承载能力大、应用前景广的新型气磁复合动压止推轴承。基于静磁学理论建立了永磁磁浮轴承承载能力的理论模型,推导出轴向永磁磁浮轴承承载能力与结构参数、转速之间的关系。利用MATLAB编程进行可视化模拟计算,得出永磁轴承承载能力与轴承间隙的关系曲线,为永磁磁浮轴承的设计及性能测试奠定了理论基础。以气体动压原理为基础建立了螺旋槽型气体动压推力轴承承载能力的理论模型,计算得出气体动压轴承的理论承载能力与转速的关系。结果表明当转速达到12000r/min时,气体动压轴承的气浮力理论值为21N。利用流体力学软件(CFD)对气槽内空气的流速及压强分布进行仿真模拟,分析了了影响气体动压轴承承载能力的因素,特别是是轴承转速与承载能力的关系。实现气磁复合动压轴承组件的研制。在气体动压止推轴承的轴承上、下片内分别嵌入直径30mm,高7.95mm的圆柱形永磁体。气体动压轴承的上下片均采用45号钢加工,外径均为80mm,其中下片旋转,上片只沿轴向窜动,气体动压轴承下片表面加工有螺旋形气槽。为了测试气磁复合动压轴承的性能,设计并搭建了气磁复合动压轴承测试试验台。该试验台主要由钢架结构、传动系统、加载装置、调速和测速装置组成,具有性能稳定、操作方便等特点。分别对气体动压轴承和永磁磁浮轴承进行了承载能力测试及轴承性能研究,有效地解决了气磁复合动压轴承中气体轴承和永磁轴承两者的耦合性问题。测试结果表明转速为12000r/min时,气磁复合动压轴承能稳定工作,承载能力达到126N。更多还原

【Abstract】 The current rapid development of science and technology has a strict requirement to the precision of the shaft of some device. The research level of ultra-precision rotary shaft matters the development of space technology, precision machine tools and precision instruments and meters industry. It’s a integrated reflection of national industrial and military technology. Gas bearing and magnetic Bearing are the first choice for bearing of precision shafting. However, they have such defects as the difficulty to control the gas bearing and low carrying capacity of magnetic bearing. A new gas-magnetic dynamic pressure thrust bearing which has a compact structure, large carrying capacity and wide application prospect is proposed in the paper.Based on the theory of static magnetism, the theoretical model of the carrying capacity of permanent magnet magnetic bearing is built. The relationship between structural parameters, speed and carrying capacity of axial permanent magnet magnetic bearing is deduced. The relationship between carrying capacity of permanent magnet magnetic bearing and bearing clearance is got with the visualization simulation of MATLAB. The theoretical basis has been laid for the design and performance testing of permanent magnet magnetic bearing.Based on gas dynamic pressure principle, the theoretical model of the carrying capacity of spiral groove gas dynamic pressure thrust bearing is built. The relationship between the theoretical carrying capacity of gas dynamic pressure bearing and speed is calculated. When the speed is 12000r/min, the air buoyancy of gas dynamic pressure bearing is 21N. The velocity and pressure distribution of the air in the gas tank is simulated with fluid dynamics software(CFD). Finally the factors which influence the carrying capacity of gas dynamic pressure bearing are found, especially the relationship between bearing speed and carrying capacity.The manufacture of components of gas-magnetic dynamic pressure bearing is realized. Two cylindrical permanent magnet of 30mm diameter and 7.95mm height are embedded individually in the upper side and lower side of gas dynamic pressure thrust bearing. The upper and lower side of gas dynamic bearing with 80mm outer diameter are made of 45#. The lower side rotates and the upper side moves along the axis only. The spiral gas groove is machined on the surface of the lower side.In order to test the performance of bearing, the test-bed of gas-magnetic dynamic pressure bearing is designed and manufactured. The test-bed is mainly composed of steel-framed structure, transmission system, loading equipment, timing and speed measuring device. The performance of the test-bed is stable and it’s easy to operate. Through the carrying capacity testing and bearing performance study of air dynamic pressure bearing and permanent magnet magnetic bearing individually, the coupling problem between them in the gas-magnetic dynamic pressure bearing is fully solved. The test results show that when the speed is 12000r/min, gas-magnetic dynamic pressure bearing can work stably and its carrying capacity is up to 126N.更多还原