【作者】 孟彬；

【导师】 阮健；

【作者基本信息】 浙江工业大学 ， 机械电子工程， 2013， 博士

【摘要】 近年来,利用液压伺服螺旋机构原理工作的2D阀因具有结构简单、响应速度快、精度高和抗污染能力强等优点,而在金属材料试验机、地震模拟震动台以及相关航空航天领域得到了广泛应用。现有2D阀用电-机械转换器为商用混合式步进电机,其本身是作为电机伺服控制系统中的控制兼驱动电机而诞生,并非专门面向阀用的电-机械转换器,因而具有结构较为固定单一、转动惯量大、动态响应受限制、不具备湿式耐高压能力等缺点,严重妨碍了2D阀的应用扩展和结构创新。电-机械转换器作为2D阀的核心部件,是连接电信号与机械动作之间的桥梁,其性能对2D阀的整体性能起着决定性的影响作用。研制高性能的新型电-机械转换器以提升2D阀的性能并拓宽应用场合,是其能否进一步得到发展的关键所在。本文对2D阀用电-机械转换器的新结构及其应用展开研究,具有重要的理论意义和工程实用背景。本文的主要研究内容和成果如下：1.对现有2D阀用电-机械转换器商用混合式步进电机作了深入分析,指出其具有部分输出力矩损失、功率重量比低、转动惯量大、本体结构和驱动电路较为复杂以及不具备湿式耐高压能力等缺陷。2.提出了低惯量旋转电磁铁和耐高压旋转电磁铁两种2D阀用电-机械转换器的新结构,结合电磁场有限元模拟分析了其工作原理,验证了方案的正确性；对以定子轴向分相来构成电-机械转换器的方式作了深入研究,从耐高压旋转电磁铁引申出了单相旋转电磁铁、双相直动电磁铁和单相直动电磁铁的新方案。3.制作了50齿和18齿两种不同转子齿数的低惯量旋转电磁铁样机,采用磁路解析、有限元模拟和实验研究的手段对其性能进行了研究。50齿和18齿样机的矩角特性均呈正弦波形,在3.5A电流下的最大静力矩分别达到约0.09N-m和0.082N·m,在-3dB下的幅频宽分别约为220Hz和125Hz,在-90。时的相频宽分别约为220Hz和130Hz,阶跃响应上升时间分别约为5.6ms和5.5ms,实验结果和仿真结果基本一致,表明该类型电磁铁具有优异的静动态特性,适用于对动态特性要求较高的应用场合。对比两种样机的实验结果也可以看出,定转子双凸齿类型的电磁铁各项静动态特性随着定转子齿数增加而提升,通过调节齿数,可以得到分别适用于电液伺服阀和比例阀等不同应用场合的电-机械转换元件。4.制作了转子15齿的耐高压旋转电磁铁样机,采用磁路解析、有限元模拟和实验研究的手段对其性能进行了研究。实验结果表明电磁铁的矩角特性呈正弦波形,3.5A电流下的最大静力矩达到约0.19N·m,-3dB下的幅频宽约为113Hz,-90°时的相频宽约为65Hz,阶跃响应的上升时间约为18ms,除齿槽力矩稍有误差外,其余实验结果和仿真结果基本一致,表明电磁铁具有较好的静动态特性,适合作为具有湿式耐高压要求的电-机械转换器。5.针对原有液压伺服螺旋机构不能同时兼顾零位泄漏和动态响应的缺陷,提出了一种新型“槽对槽”先导级的液压伺服螺旋机构方案,建立了数学模型并推导了传递函数,对动态特性进行了模拟,其仿真幅频宽达到了约280Hz/-3dB,阶跃响应的上升时间约为4.4ms,表明即使在先导级零遮盖的情况下,该新型液压伺服螺旋机构依然具有非常好的动态特性。6.作为耐高压旋转电磁铁的应用实施例,提出了非直驱式2D阀的结构方案,阀体部分采用“槽对槽”型液压伺服螺旋机构,设计并加工了非直驱式2D阀的实验样机,搭建了实验台架并实测了样阀的主要静动态特性,在系统压力20MPa下样阀的零位泄漏约为5.4L/min,额定流量约为100L/min,-3dB下的幅频宽约为17Hz,-90°时的相频宽约为10Hz,阶跃响应的上升时间约为46ms,稳态误差基本为零。更多还原

【Abstract】 In recent years2D valve based the principle of hydraulic servo screw mechanism has been widely used in the metal material tester, earthquake simulator and areas of aeronautics and astronautics since it has advantages of simple structure, fast dynamic response, high accuracy and excellent anti-pollution capability. The electro-mechanical converter for2D valve is commercial hybrid stepping motor, which was not specially developed for valve electro-mechanical converter but for control and driving motor of electro-mechanical servo system. Therefore it has shortcomings of inflexible structure, large rotating inertia, limited dynamic response and deficiency of high pressure resistance, which heavily influence the application extension and structure innovation of2D valve. As a crucial component of2D valve, electro-mechanical converter functions as the bridge between electrical signal and mechanical movement, and it has a decisive influence on the overall performance of2D valve. The aim of developing novel electro-mechanical converter is to improve performance of2D valve and extend its application area, which also acts as the key of whether2D valve can be further developed or not. The research to novel electro-mechanical converter structure has both theoretical significance and engineering practical background. The main research content and achievements in this dissertation are listed as follows:1. The disadvantages of commercial hybrid stepping motor are deeply analyzed and main defects such as output torque loss, low power weight ratio, large rotating inertia, complicated structure and driving circuit and deficiency of high pressure resistance are pointed out.2. Two novel structures of electro-mechanical converter for2D valve, i.e. rotary electromagnet with low inertia and rotary electromagnet with high pressure resistance are proposed. The working principles are analyzed and correctness of schemes are validated both by finite element analysis. The method of constituting electro-mechanical converter based on approach of stator axial phase separation is deeply researched and another three new structures, i.e., rotary electromagnet with single phase, direct-acting electromagnet with single phase and direct-acting electromagnet with double phases are deduced from the scheme of rotary electromagnet with high pressure resistance.3. Two prototypes of rotary electromagnet with low inertia with different rotor tooth numbers are manufactured. The performance of electromagnets are studied by using approaches of magnetic circuit analytical method, finite element simulation and experimental study. Experimental results illustrate that torque-angle characteristics of electromagnets with rotor teeth number of50and18are both sinusoidal waveform, whose maximum static torque under current of3.5A reach about0.09N·m and0.082N·m, respectively. And the amplitude frequency widths with-3dB are about220Hz and125Hz, respectively. The phase frequency widths with-90°are about220Hz and130Hz, respectively. The rise times of step response are about5.6ms and5.5ms, respectively. The experimental results are in good accordance with simulated results. It can be concluded that the electromagnets have both excellent static and dynamic characteristics, which is suitable for applications where high dynamic response is perferred. Besides, from comparison of two prototypes with different rotor tooth number it can be found that the main static and dynamic characteristics of electromagnet with double salient structure on both stator and rotor can be further improved by increasing tooth number. Therefore different electromagnets can be obtained by adjusting tooth number which is suitable for different applications such as electrohydraulic servo valve, proportional valve and etc., respectively.4. The prototype of rotary electromagnet with high pressure resistance is manufactured. The performance of electromagnet is studied by using approaches of magnetic circuit analytical method, finite element simulation and experimental study. Experimental results illustrate that torque-angle characteristic of electromagnet with rotor teeth number of15is sinusoidal waveform, whose maximum static torque under current of3.5A reaches about0.19N·m. The amplitude frequency width with-3dB and phase frequency widths with-90°are about113Hz and65Hz, respectively. The rise time of step response is about18ms. The experimental results are in good accordance with simulated results except for slight deviation of cogging torque. It can be concluded that the electromagnet has both good static and dynamic characteristics, which can be used as electro-mechanical converter where high pressure resistance is preferred.5. In order to solve the problem that traditional hydraulic servo screw mechanism can not have both low leakage of pilot stage and fast dynamic response, a novel hydraulic servo screw mechanism that has "groove to groove" pilot stage is proposed in this paper. The mathematical model is established and transfer function is derived. Its dynamic characteristics are simulated and results show that the simulated amplitude frequency width reaches about280Hz/-3dB and rise time for step response is about4.4ms, which demonstrates that the novel hydraulic servo screw mechanism has excellent dynamic response even with zero lap of pilot stage.6. In order to act as an application example of rotary electromagnet with high pressure resistance, structures of non-direct driving2D valve is put forward, which are based on hydraulic servo screw mechanism that has "groove to groove" pilot stage. The prototype is designed and manufactured. The test rig is built and main static and dynamic characteristics are measured. Results show that with system pressure of20MPa the zero position leakage and rated flow of prototype are about5.4L/min and100L/min, respectively; the amplitude frequency width with-3dB and phase frequency widths with-90°are about17Hz and10Hz, respectively. The rise time of step response is about46ms with almost zero steady error.更多还原