高速主轴回转误差动态测试与分析

应用双向法设计测试系统,对主轴的回转误差进行动态测试.该系统由高精度标准棒、非接触位移传感器和LMS TEST,LAB采集器组成.阐述了回转误差的测试原理,针对机床主轴测试中标准棒的安装偏心问题,提出了有效解决方法,并进行了实验研究.     

Thermal characteristics analysis and experimental study on the high-speed spindle system

The International Journal of Advanced Manufacturing Technology - In order to avoid the sudden failure of high-speed spindles in the actual machining process caused by an excessive temperature rise...     

高速精密主轴轴承热特性的计算及分析

轴承的发热变形是影响高速精密主轴系统刚度和加工精度的重要因素。本文采用节点网络法，对以电主轴轴承、主轴、轴承座为一体的系统建立了温度场计算模型，求出了系统各关键节点的温升情况，分析了转速、切削力、润滑方式等因素对节点温度的影响，得出了若干有意义的结论。     

Thermal error modeling by integrating GA and BP algorithms for the high-speed spindle

Thermal error is one of primary reasons affecting the cutting accuracy of a machine tool. Especially, high-speed spindle’s thermal error restricts the improvement of high-precision machine tool accuracy. In this paper, the traditional back propagation (BP) neural network modeling principle is firstly analyzed. Then, considering the BP network, which is simple and adaptive but converges slowly and is easy to reach local minima, a genetic algorithm (GA) is introduced to optimize BP network’s initial weights and thresholds. Lastly, the network is trained using combined GA and BP technologies with practical thermal error sample data. In experiments of thermal error prediction of the high-speed spindle in a machine tool, the average compensation rate is increased from 89.03 % of BP model to 93.155 % of GABP model. Therefore, GABP model shows its effectiveness in quickly solving the global minimum searching problem.     

Dynamics modeling and modal experimental study of high speed motorized spindle

This paper presents a dynamical model of high speed motorized spindles in free state and work state. In the free state, the housing is modeled as a rotor with equivalent masses including bearing pedestals, motor stator and rear end cover. As a consequence, a double rotor dynamics can be modeled for high speed motorized spindles by a bearing element which connects the housing and bearing pedestals. In the work state, the housing is fixed and the system becomes a bearing-rotor dynamical model. An excitation-measurement test in the free state is designed to analyze the cross spectral density and auto spectral density of input and output signals. Then the frequency response function of system and coherence function of input and output signals which are used to analyze the inherent characteristics of the double- rotor model can be obtained. The other vibration test in the work state is designed to research the dynamical supporting characteristics of bearings and the effects from bearings on the inherent characteristics of the system. The good agreement between the experimental data and theoretical results indicates that the dynamical model in two states is capable of accurately predicting the dynamic behavior of high speed motorized spindles.     

高速电主轴的油气润滑

在高转速轴承寿命试验机电主轴中选用了油气润滑方式,实施稳定的微量油润滑.通过实验确认,DMN达150mm.r/min,解决了油雾润滑污染环境的问题,使环境质量良好。     

Thermal model of high-speed spindle units

For the purpose to facilitate development of high-speed spindle units (SUs) running on rolling bearings, we have developed a beam element model, algorithms, and software for computer analysis of thermal characteristics of SUs. The thermal model incorporates a model of heat generation in rolling bearings, a model of heat transfer from bearings, and models for estimation of temperature and temperature deformations of SU elements. We have carried out experimental test and made quantitative evaluation of the effect of operation conditions on friction and thermal characteristics of the SUs of grinding and turning machines of typical structures. It is found out that the operation conditions make stronger effect on SU temperatures when rpm increases. A comparison between the results of analysis and experiment proves their good mutual correspondence and allows us to recommend application of the models and software developed for design and research of high-speed SUs running on rolling bearings.     

Influence of thermal effect on dynamic behavior of high-speed dry hobbing motorized spindle system

Journal of Mechanical Science and Technology - This paper is devoted to investigating the influence of thermal effect on the dynamic behavior of a motorized spindle system in high-speed dry hobbing...     

Performance analysis of high-speed spindle aerostatic bearings

The methods adopted to derive the pressure distribution and precision of bearing rotation are fundamental issues in the arena of gas bearing design. The current study presents a detailed theoretical analysis of bearing performance, in which the gas flow within the bearing is initially expressed in the form of simplified dimensionless Navier Stokes equations. Adopting the assumption of mass flow continuity between the bearing clearance and the orifice, the nonlinear dimensionless Reynolds equation is then derived and subsequently discretized using the Newton method. Finally, the modified Reynolds equation is solved by means of the iterative rate cutting method. The current numerical models are valid for the analysis of the film pressure distribution, friction effects, loading capacity, rigidity, lubricating gas flow rate, and eccentricity ratios of a variety of static and dynamic pressure aerostatic bearings, including high-eccentricity ratio journals, high-speed non-circular journals, thrust bearings, and slider bearings, etc. The proposed analytical models provide a valuable means of analyzing the static and dynamic performance of a high-precision rotating gas bearing, and allow its design to be optimized accordingly.     

机械式高速主轴单元的改进设计

为满足更高的生产需求,对一款机械式主轴单元进行了改进设计:主轴支撑轴承的优化配置,使主轴单元的刚度和使用寿命得以兼顾;高效的气密封结构大大增进了主轴单元工作的可靠性;最后,对主轴尾端结构进行了轻量化改进,不仅节约了成本,而且提高了主轴单元的工作效率。     

Comprehensive measurement and evaluation system of high-speed motorized spindle

Reducing the manufacturing time is the trend of high-precision manufacturing, and the precision of a work-piece is very important for manufacturing industry. The high-speed motorized spindle is the most critical part and becoming more widely used in the machine tool at present, and its precision may affect the overall performance of high-speed cutting. Most of the studies on high-speed cutting are focused on the cutting force, the vibration of the spindle and effects of the spindle’s thermal deformations; hence, how to roundly measure and objectively evaluate high-speed spindle is an imminence question of it because the comprehensive dynamic properties and evaluation system of spindles directly affect the cutting ability of the whole machine tool before they are manufactured. This paper presents a comprehensive measurement and evaluation system of high-speed motorized spindle, which reflects the overall performance of motorized spindle and bases on international standard.     

高速陶瓷电主轴设计及性能分析

为了提高高速主轴系统的性能采用热压Si3N4工程陶瓷作为主轴材料设计了高速电主轴,对其静动态性能进行了有限元分析。结果表明,陶瓷电主轴比传统的钢质电主轴具有更加优良的动静态性能,静刚度、固有频率、临界转速都有不同程度的提高,更加适合于高速应用场合。     

高速电主轴回转精度测试技术探讨

利用电涡流传感器及位移信号采集系统对传感器的数据同步采集,并同时将位移信号转化为模拟的电压信号;模拟的电压信号通过A/D转化为数字信号,经数据LMS信号采集系统传给计算机,计算机通过Test.Lab Signature软件,对数据进行分析处理,对于研究高速电主轴的回转精度进行了测试技术方面的探讨,希望对电主轴的研究有一定的借鉴作用。     

高速电主轴结构的改进

对高速电主轴轴承的配置和预紧方式的选择进行了分析研究,并建立了高速电主轴轴承-主轴系统的参数化有限元模型,运用ANSYS有限元分析软件的优化设计功能,以提高主轴刚度为目标,通过指定参数作为设计变量、状态变量和目标函数来建立分析程序,并以设计变量为自变量,不断改变其数值,迭代计算直至目标函数值达到最小,迭代过程中,状态变量用于控制自变量取值。结果表明:主轴支承跨距优化后,刚度和一阶固有频率得到了一定程度的提高,从而为电主轴结构的改进提供了理论基础。     

高速雕刻电主轴性能分析及优化设计

通过ANSYS建立三维模型,对自产100HSK电主轴进行静态、动态性能分析,得到相应的临界转速和谐响应曲线,为小刀具雕刻时最高转速的确定和刀刃数量的选择提供依据.并进一步针对轴承最佳跨距进行优化设计,合理设计转子尺寸,改善其静态、动态性能.     

高速铣削加工的数学模型建立和实验研究

在高速铣削机理研究中,铣削参数的应用实验研究是至关重要的.通过单因素和多因素实验,研究高速铣削参数对已加工工件表面粗糙度和表层残余应力的影响规律.实验表明,高速铣削能够获得较好的工件表面质量.     

数控绕线机高速主轴单元的动力学分析

为了分析并提高数控绕线机高速主轴单元的动态性能,以转子动力学有限元理论为基础,以ANSYS有限元分析软件为平台,在考虑支撑刚度和轴系零件的情况下,对SKR-4DQ型全自动数控绕线机主轴单元进行了动力学分析,得出了在不同的支撑刚度下,其高速主轴单元的前3阶振型和固有频率;分析了不同的支撑刚度对主轴固有频率的影响.计算和实验结果表明,所设计的SKR-4DQ型全自动数控绕线机主轴单元能满足在额定转速15 000 r/min下为刚性转子的设计要求.     

Centrifugal force induced dynamics of a motorized high-speed spindle

Trend of the high-speed and high efficiency machining has pushed the continuous demand of higher spindle speed and power for the machining center application. Because the extremely high speed produces significant centrifugal force, it creates a need to predict the spindle dynamical characteristics at dynamic states. This work presents analysis results of the spindle dynamic of a motorized high speed spindle with angular ball contact bearings. For a machining center, two major subsystems determining the overall spindle stiffness are the shaft/bearing subsystem and the draw bar mechanism subsystem. Shaft/bearing stiffness as well as the natural frequency decreased at high speeds due to the bearing softening and gyroscopic effect. The bearing softening is the major reason of the reduced spindle stiffness, while the gyroscopic effect plays the secondary effect. Angular contact ball bearing softening at high speed is due to the reduced contact load and increased contact angle at the ball/inner-raceway contact interface caused by the centrifugal force. For the draw bar mechanism, analysis results show that the dynamic draw force at high speeds is significantly increased from that designed at the static state. Because the toolholder/spindle interface stiffness is proportional to the draw force, centrifugal force theoretically contributes a plus to the spindle stiffness at dynamic state. The dynamic draw force, however, is dependent on the friction loss inside the draw bar mechanism. Because of the low friction coefficient, the ball-type mechanism is superior to the wedge type mechanism.