新型力反馈式二维电液伺服阀关键技术的基础研究

This project proposes structure and working principles of a novel two dimensional electro-hydraulic servo valve with force feedback control. The pilot stage of valve is realized via improved two dimensional flow amplification mechanism, which can effectively overcome the influence of fluid force and thus obtain ideal static and dynamic characteristics. The novel torque motor with paddle wing is used as electro-mechanical converter to drive spool rotate directly and also achieve closed force feedback loop from spool axial movement to torque motor through variation of armature electro-magnetic torque, which originally lead from variation of working air gap. The theoretical basis for spool rotation resistance torque is provided through deep research of generation mechanism for hydraulic clamping, clamping force distribution and optimization of resistance torque reduction. The theoretical foundation for electro-mechanical converter of valve is established via research of driving and feedback characteristics of torque motor with paddle wing. The theoretical basis for valve structure optimization and design is laid through deep research of half-bridge of pilot stage, valve static and dynamic characteristics and closed-loop stability, which also can provide examples for future engineering application. The novel servo valve possesses advantages of excellent oil anti-pollution capability, dynamic response, large flow control capability and structure& processing, and therefore it is one of the ideal solutions for servo valve with requirement of high frequency and large flow control. The electro-hydraulic servo valve with independent intellectual property will be actively promoted via deep and systematic research of this novel servo valve.

本项目提出了一种新型力反馈式二维电液伺服阀的结构原理，该阀采用改进型的二维流量放大机构来实现导控级功能，以有效克服液动力的影响从而获得理想的静动态特性；采用桨翼式力矩马达的创新结构直接驱动阀芯旋转，并以工作气隙变化进而导致衔铁电磁力矩变化来实现阀芯位移对力矩马达的力反馈。通过对该阀液压卡紧的产生机理、卡紧力分布以及减阻优化进行深入研究，为阀芯旋转阻力矩的确定提供理论基础；通过对桨翼式力矩马达的驱动和反馈特性的研究，为其作为阀用电-机械转换接口确立理论依据；通过对该阀的半桥导控级结构、静动态特性及闭环稳定性进行深入研究，为其结构优化设计奠定理论基础，同时为未来工程应用提供范例。该新型伺服阀在抗油液污染能力、动态性能、大流量控制能力及结构工艺等方面具有很多优点，是高频大流量伺服阀的一种理想解决方案，对其进行深入、系统的研究，必将对形成具有自主知识产权的电液伺服阀技术起到积极的推动作用。

（1）基于单相对称磁路设计了一种新型湿式力矩马达，制作了实验样机并搭建了实验平台，分别基于磁路解析、数值模拟和实验研究了该马达的力矩-转角特性以及频率响应等主要特性。实验结果和模拟结果基本相符，显示该马达的矩角特性曲线呈线性关系，且幅值随着电流增加而增大，其静力矩幅值达到0.042N•m，实测频响达到10Hz左右。.（2）设计了一种具有反馈机能的新型浆翼式力矩马达，加工了三种不同浆翼倾角的马达样机并搭建了实验台架，分别采用磁路解析、有限元模拟和实验研究的方法研究了该马达的反馈力矩和衔铁轴向位移之间的特性关系。实验结果和模拟结果基本相符，显示该马达的反馈力矩-位移特性曲线呈线性关系，且幅值随着衔铁位移增加而增大；对比不同倾角的特性曲线可以得知，增大浆翼倾角是增加反馈力矩的有效手段。.（3）研究了二维伺服阀的关键零件二维弹簧杆，设计了三种不同的方案，通过力变形分析确定了每一种方案的结构参数，通过力学仿真验证了计算的正确性以及应力的安全性。结果表明：三种弹簧杆的计算结果基本与仿真结果相符，但方案一的弹簧杆结构造成的气隙过大，会影响力矩马达的性能，方案二通过运动变形补偿运动后的位移变化，方案三通过塑性变形来补偿位移，方案二、三更加有利于零部件的加工以及后续研究的开展。.（4）推导了二维伺服阀阀芯卡紧力计算方法，进而得到旋转阻力矩的计算方法，通过对阀芯转动阻力矩的研究为确定浆翼式力矩马达的静态特性奠定基础；应用缝隙流动理论和MATLAB仿真软件分析，得到其径向卡紧力与偏心量和高低压孔夹角间的关系，并提出降低二维伺服阀阀芯卡紧力的改进方案。