划片机高速空气静压电主轴关键技术的研究

划片机是最关键的集成电路封装设备,高速空气静压电主轴是划片机的核心部件。从主轴结构出发,研究空气轴承、主轴电机、动平衡、转子与旋转轴的联接、精密加工、主轴热变形的控制等高速空气静压电主轴的关键技术。     

划片机空气静压电主轴径向轴承的设计

径向轴承是划片机空气静压电主轴的关键零件,径向轴承的结构及尺寸直接影响转轴的高速旋转精度及工作性能。采用表压比法对划片机空气静压电主轴径向轴承进行设计计算,确定径向轴承的结构参数。     

切割机空气静压电主轴止推轴承的设计

止推轴承是切割机空气静压电主轴的关键零件,止推轴承的结构及尺寸直接影响主轴的工作性能和稳定性。采用表压比法对切割机空气静压电主轴止推轴承进行设计计算,确定止推轴承的结构参数。     

空气静压电主轴的稳定性研究

空气静压电主轴是高速精密加工设备的关键部件之一，其工作稳定性直接影响整机的使用性能和寿命。从自激振动和转轴涡动两个方面，对空气静压电主轴稳定性的主要影响因素进行了分析研究;并结合空气静压电主轴在半导体封装设备晶圆减薄机和划切机上的应用，重点对气浮轴承内部气容比、节流塞形式、进气压力、径向轴承结构参数、径向轴承形状误差以及动平衡等方面提出了合理的优化建议和方法，这些建议和方法在实践中起到了良好作用。     

划片机空气静压电主轴材料选用及加工工艺研究

从划片机空气静压电主轴的结构出发,分析了主轴的技术要求,提出了主轴材料选用的基本原则,介绍了划片机主轴的常用材料,重点论述了划片机主轴的加工阶段划分、热处理安排和定位基准选择,给出了划片机主轴的加工工艺路线图,并在实践中进行了验证。     

切割机空气静压电主轴径向承载力及刚度的设计

径向承载力及刚度是影响切割机空气静压电主轴高转速下工作稳定性的重要因素,也是切割机空气静压电主轴重要的设计指标。本文采用工程计算方法,对切割机空气静压电主轴径向承载力及刚度进行设计计算。     

划片机气静压电主轴热变形的有限元分析

分析划片机气静压电主轴的发热和热传递;建立气静压电主轴的热-应力有限元分析模型,用ANSYS软件计算主轴的温度场分布及主轴的热变形值。根据计算结果,提出减小主轴热变形及消除热变形造成的加工误差的措施。     

空气静压电主轴振动模糊控制技术研究

为提高空气静压电主轴运行稳定性,在引入小波阈值降噪方法的基础上,针对其振动面模糊控制技术进行研究。通过空气静压电主轴振动控制信号模糊量化处理、基于小波阈值降噪的电主轴振动信号虚假模态剔除、非模糊化精确控制量转换及控制比例因子输出,提出一种全新的电主轴振动模糊控制技术。实验结果表明,新的控制技术能够将电主轴的振动幅度控制在安全范围内,减少甚至避免了电主轴发生异常振动,提升了空气静压设备整体运行的稳定性。     

基于压电陶瓷作用的气体主轴抑振研究

针对空气静压主轴气膜刚度不高,在工作中易受自身及外部激励的影响,从而产生不平衡振动的现象,设计了一种基于压电陶瓷的可控空气静压径向轴承,研究了压电陶瓷的相关特性。结合气体主轴建立了轴承转子压电陶瓷的耦合模型,并在此基础上建立了基于扩张观测器的滑模控制器,同时将压电陶瓷综合控制器串联其中,在限制条件内利用控制器使压电陶瓷挤压气膜为主轴提供有效的主动控制力,从而抑制空气静压主轴的振动。研究结果表明,利用压电陶瓷对空气静压主轴系统的振动进行抑制取得了良好的效果,对于主要控制点可使其振动位移减小99.17%,对于次要控制点均有不同程度的减振效果,最多可减少94.36%。     

划片机气静压电主轴热态特性研究

从划片机气静压电主轴的工作机理出发,研究主轴电机的功率损耗发热、空气轴承的气膜剪切摩擦发热;根据分析结果提出减小主轴发热和加强散热的措施。     

Vibration monitoring of motorized spindles using spectral analysis techniques

High speed machining (HSM) technology is used in a broad range of applications to machine ferrous metals and nonmetallic material. The motorized spindle is one of the major elements to keep the machine running at high productivity. Though the motorized spindle will generate high power and torque at high speed, high removable rate, but the thermal characteristics are more dynamical, speed-dependent and non-linear. The air gap between rotor and stator changes with speed and time, the expansion of rotor, the highly complicated mechanical coupling as well as interface of the mechanical structure. All these factors create centrifugal force to the rotating bearings which not only heat these bearings up, causing bad tolerance, but also create the vibration problem. The worse situation may cause the bearings choked.In this paper, a piezo transducer is used to check the spindle vibration. Once the spindle is out of balance, the transducer gives a dialog response to computerized numerical controller (CNC) which is set with a control level. Based on ISO standard, 2 mm/s is the max acceptable vibration and designed in accordance with 2 V output voltage. Any higher voltage will enable the CNC shut down the spindle before the bearings are damaged. This new concept will prevent spindle from turning dead. As a result, the spectral analysis techniques can record the condition of spindle rotation even under the condition of misoperation.     

艾默生CT-SP变频器在数控走芯机电主轴上的应用

异步电机电主轴与普通的异步电机特性相差比较大,由于要对电机进行精确的矢量控制,准确的的电机参数将是必要的前提。     

Performance of induction motor with free-rotating magnets insideits rotor

This paper presents a new induction motor that has free-rotating magnets inside a rotor. The magnets can revolve freely against the rotor with the shaft. In this motor, the airgap flux is provided by both rotating permanent magnets and the stator coil current. A prototype motor was fabricated by modifying the rotor of a conventional three-phase four-pole 400 W squirrel-cage induction motor. The experimental results of a prototype motor showed superior performance in comparison to conventional motors in terms of the power factor, efficiency and torque characteristics. The power factor can be controlled to be unity, leading or lagging by changing the supply frequency and/or source voltage. The efficiency of the motor, over a wide output power range, is remarkably higher than that of the same size conventional induction motor. A high torque can be obtained in a high speed area     

高速空气静压电主轴的振动及控制策略

从主轴的结构和工作机理出发,分析气锤振动、受迫共振、机械振动及电机不平衡磁拉力等引起主轴振动的关键因素,依据分析结果提出减小或消除主轴振动的措施。     

Performances of bearingless and sensorless induction motor drive based on mutual inductances and rotor displacements estimation

A self-sensing bearingless motor is considered as an effective solution to reduce cost and shorten a shaft length. In this paper, a novel estimation method of a rotor displacement is proposed. The method is based on the detection of currents induced by mutual inductances, which vary as a function of the rotor displacements. A high-frequency carrier voltage is superimposed on a motor main terminal voltage. The induced carrier-frequency current component is distinguished from the suspension-winding current. The carrier signal is selected high enough to suspension-current components. However, the carrier current is disturbed in transient conditions. The disturbed current results in a vibration of the estimated rotor displacements. A suspension-current estimator is proposed to reduce this vibration and to obtain the difference between the detected current and the estimated current. As a result, the disturbance vibration is significantly reduced. It is shown that a successful magnetic suspension is realized with the proposed method.