【作者】 陶利民；

【导师】 温熙森；

【作者基本信息】 国防科学技术大学 ， 机械工程， 2006， 博士

【摘要】 旋转机械是机械系统的重要组成部分,在国防和国民经济众多领域中发挥着巨大作用。转子不平衡是旋转机械中的常见问题,也是诱发转子系统故障的主要原因之一。因此,开展动平衡技术研究具有重要的学术和工程应用价值。近年来,随着电子、计算机和测试等技术的迅猛发展,动平衡技术也得到了很大发展,其研究成果对推动旋转机械向高速、高效、高可靠方向发展起到了重要作用。目前,有关转子动平衡技术的研究主要集中在动平衡测试、非对称/非平面模态转子平衡、无试重平衡、自动平衡等技术领域。为了提高转子平衡精度与效率,论文从不平衡动态响应分析出发,围绕动平衡测试与自动平衡中的窄带跟踪滤波、自动平衡策略等关键技术问题展开深入研究。论文主要研究工作包括:1、为了掌握转子系统振动响应与不平衡量及转子系统参数的关系,针对平面转子、刚性转子、挠性转子等典型转子系统,在总结、归纳已有研究成果的基础上,采用理论分析与数值仿真相结合的方法,深入研究了在恒加速条件下转子系统参数对转子瞬态不平衡响应的主要影响规律。研究结果表明:在恒加速条件下,转子同频振动分量与转子的转速、支承阻尼等因素密切相关,当角加速度较小且阻尼较大时,其瞬态响应对转速的波动不敏感;而当角加速度较大或阻尼较小时,恒加速过程不平衡响应与稳态响应在临界转速附近将产生明显的差异。2、为了适应转速波动时高精度动平衡测试的需求,精确、快速地分离出不平衡响应中的同频振动分量,深入研究了两种新型模拟窄带跟踪滤波技术:(1)利用开关和电容可等效电阻的原理,导出了开关电容跟踪滤波方法,设计研制了一种新的开关电容模拟窄带跟踪滤波器;(2)利用互相关原理,导出了相关跟踪滤波方法,并采用乘法数模转换器(MDAC),设计研制了MDAC模拟窄带跟踪滤波器。3、为了实现平衡头的快速、精确控制,针对初始状态未知的极坐标型平衡头,提出了两种各具特点的自动平衡策略和算法:(1)对单面坐标轮换寻优法进行了改进,提出了多轮坐标轮换寻优法,并将单面坐标轮换寻优法推广应用到双面转子的自动平衡,证明了该方法能得到全局最优解;(2)提出了基于影响系数法的快速自动平衡策略及其递推算法,快捷、有效地抑制了振动噪声、测量误差、控制误差等对平衡精度的影响。4、为了快速、准确地掌握不平衡量在转子上的分布情况,针对信噪比低、工作转速范围宽、转速波动时的振动信号特点,深入研究了程控放大、程控积分、外触发等角度采样、不平衡量快速精确解算等信号处理技术;通过技术集成,研制了便携式高精度动平衡测试系统。为了避免转子系统离线平衡时的反复起、停车过程,及时补偿工作过程中出现的随机不平衡,提出了两种新型平衡头结构,其中,基于感应子式永磁步进电机原理的平衡头结构紧凑、精度高,而基于永磁式步进电机驱动的平衡头更容易实现;以此为基础,设计研制了基于红外控制信号传输的新型转子自动平衡系统。5、对研制的动平衡测试系统进行了整机性能测试,并分别应用于低速鼓风机转子、高速陀螺转子以及特殊支承的磁悬浮转子的动平衡,均达到了较好的平衡效果,表明该测试系统在硬支承、软支承动平衡机以及现场动平衡测试时均能达到较高的平衡精度。应用坐标轮换寻优自动平衡策略和基于影响系数法的快速自动平衡策略对单面转子进行了自动平衡实验,结果表明,坐标轮换寻优法简单实用、操作安全,而基于影响系数法的快速自动平衡策略有较高的平衡精度和平衡效率。综上,论文在深入分析典型转子系统不平衡动态响应特性的基础上,提出了两种模拟窄带跟踪滤波方法、两种各具特点的自动平衡控制策略和算法以及不平衡量的快速、精确解算方法,设计研制了便携式高精度动平衡测试系统,提出了两种新型平衡头结构,设计研制了基于红外控制信号传输的自动平衡系统,同时给出了进一步研究工作设想。更多还原

【Abstract】 Rotating machine is an important part in mechanical system, which has a great significance in defensive and civil domain. Imbalance is a common problem for rotors, and also the principal reason of faults in rotor systems. The research of dynamic balancing technology has important scientific and engineering significance. With the rapid evolvement of electronics, computer, and measurement, dynamic balancing technology has been developed greatly in recent years, which helps to build up a trend of high-speed, high-efficiency, and high-reliability for rotor systems. At present, related researches are centering on dynamic balancing measurement, non-symmetrical/non-planar modal rotor balancing, balancing without trial weights, automatic balancing, and so on. Aimed to increase balancing precision and efficiency for rotors, this dissertation analyzes dynamic response of imbalance at first, discusses the related key technologies further in dynamic balancing measurement and automatic balancing such as narrowband tracking filtering, automatic balancing strategy, and so on. The main contents are as follows:1. In order to interpret the relationship between vibration response and variables of imbalance together with parameters of system in typical rotor under constant acceleration, such as planar rotor, rigid rotor, and flexible rotor, the main influencing rules of system parameters on the transient imbalance response are studied deeply by theoretic analysis and numerical simulation on foundation of the existing research results summarized and concluded. The analysis results indicate that the vibration fractional factor with rotating frequency has a close relationship with both rotating speed of rotor and damping of bearing under constant acceleration. When rotating acceleration is small and damping is large, the transient response is not sensitive to the variation of rotating speed; otherwise the imbalance response with constant acceleration and the response in stable state will build up obvious differences near critical rotating speed.2. In order to adapt to the requirements of high-precision dynamic balancing measurement with rotating speed variation and to isolate the vibration fractional factor with rotating frequency from imbalance response precisely and quickly, two new types of analog tracking filtering technologies are deeply studied: (1) the tracking filtering method using switched-capacitor is deduced from the equivalent principle between switch & capacitor and resistance, and a new narrow-brand tracking filter using switched-capacitor is designed accordingly; (2) the correlative tracking filtering method is deduced from the correlation principle, and an analog narrow-brand tracking filter using Multiplying Digital-to-Analog Converter (MDAC) is designed accordingly.3. In order to realize fast and precise control of balancing head, two special types of automatic balancing strategies with the corresponding algorithms are brought forward for balancing head in polar coordinates: (1) an alternate-coordinate optimization method with multiple circulations is built up to improve alternate-coordinate optimization method for single plane in existence, and widens its application to automatic balancing for double planes which proves to be able to gain global optimal solution;(2) a fast automatic balancing strategy and its recursive algorithm are presented based on the influence coefficient method, which restrains the influences on balancing precision from vibration noises, measurement errors, and control errors rapidly and effectively.4. In order to gain the distributing condition of imbalance on rotor quickly and precisely, the signal processing technologies such as programmed amplifying, programmed integrating, equal -angle sampling with outer triggering, and precise imbalance solving are studied deeply, and a portable high-precision dynamic balancing measurement system is developed. To avoid multiple on/off process when balancing off-line and to compensate the random imbalance in running timely, two new types of balancing head structures are advanced, of which the balancing head based on the principle of permanent-magnetic-induction stepping motor has a compact structure and a high precision and the balancing head driven by permanent-magnetic stepping motor is easier to realize; and an automatic balancing system based on infrared control signal transmission is designed and developed accordingly.5. The performances of the developed dynamic balancing measurement system are tested, and then the system is applied to dynamic balancing of low-speed fan rotor, high-speed gyro rotor, and magnetic-suspended rotor respectively. The balancing effects are satisfactory, which indicate that the system has high measurement precision when applied to both dynamic balancer with hard/soft bearing and field dynamic balancing. The automatic balancing strategy based on alternate-coordinate optimization method and the rapid automatic balancing strategy based on the influence coefficient method are applied to the automatic balancing experiment of rotor with single plane, which reveals that alternate-coordinate optimization method is easy to use and safe to operate, and that the rapid automatic balancing strategy based on the influence coefficient method has high balancing precision and balancing efficiency.In sum, this dissertation analyzes the characteristics of imbalance response in typical rotors deeply at first, and brings forward two types of analog narrow-band tracking filtering methods and two special types of automatic balancing control strategies with the corresponding algorithms, then develops a portable high-precision dynamic balancing measurement system, and then presents two new types of balancing head structures, and develops an automatic balancing system based on infrared control signal transmission afterwards, and gives out further imagination for future research in the end.更多还原