【作者】 马正兰；

【导师】 张永忠； 杜长龙；

【作者基本信息】 中国矿业大学 ， 机械设计及理论， 2009， 博士

【摘要】 滚筒式采煤机是高产、高效机械化采煤的主要设备,广泛应用于不同地质条件下的煤炭开采。目前在生产上存在的主要问题是块煤率低和工作时粉尘大。为此,论文开展了变速截割采煤机关键技术的研究。在对煤岩物理机械性质和截齿破煤机理分析的基础上,推算出了描述截齿各安装角度之间几何关系的表达式,建立了截齿安装角β优化的数学模型;对叶片部和端盘部截齿的配置方式和切削图形进行了分析,提出了高煤块率端盘部截齿的优化配置方式。为了提高块煤率,研究了滚筒有关截割参数对切削图面积Am和方正率ξ的影响,建立了以切削图面积Am最大为目标函数的滚筒参数优化数学模型,并应用直接比较—比例法的遗产算法进行了优化计算,得出了在不同截齿配置条件下相应的结构参数和截割参数优化值、以及高块煤率叶片部截齿的优化配置方式。高块煤率采煤机滚筒的结构优化是在一定的煤层性质条件下进行的,为了满足不同性质煤层高块煤率截割的需要,进行了采煤机变截割速度和牵引速度的优化研究;同时,提出了依据检测采煤机的截割载荷间接识别煤层的截割阻抗的方法,并以此进行截割参数的调整。针对煤矿井下采煤工作面的恶劣工况和环境条件,论文选用了微处理器S3C44B0X、高速A/D转换40kSPS、CF卡组成嵌入式采煤机截割载荷检测系统,进行了硬件和软件设计、防干扰和本质安全设计,所研制的系统在煤矿井下进行了采煤机截割载荷的实测,表明其可行性和实用性。由于开关磁阻电机(SRM)具有结构简单坚固、转子免维护、低速转矩大等优点,论文选择SRM作为采煤机变速截割的动力源;采用有限元法对SRM的磁路特性进行了分析,为SRM结构的优化设计提供理论依据;采用实验的方法,获得了采煤机牵引部SRM样机的磁链曲线,为研究SRM的特性及控制策略提供实验资料;给出了反映SRM非线性电磁特性的磁链模型的几种建模方法,并对各种模型优化的磁链曲线和样机实测磁链曲线进行对比分析,为建模方法的选择打下了基础。为了提高开关磁阻电机驱动(SRD)系统运行的可靠性,提出了无位置传感器SRM的控制策略,完成了SRD系统相关的硬件和软件设计;采用激励脉冲法对SRM的启动工作相进行选择,解决了生产实际中SRM无反转启动问题;搭建了18.5kW牵引部SRM的实验平台,开展了实验研究,实验结果验证了所提出的无位置传感器控制策略的正确性,证明了无位置传感器采煤机SRD系统的可行性与可靠性。更多还原

【Abstract】 The shearer is the main equipment for mechanization coal mining with high production and efficiency, it is widely used for coal mining under different geological conditions. At present, existing principal problems are low rate of lump coal and more coal dust. Therefore, this dissertation conducts a study on the key technology of shearer with variable speed cutting.Based on the analysis of physical mechanical property of coal and cutting mechanism of drum pick, the expressions of relation between installation angles are calculated. The mathematical model of optimizing installing angleβis established. Analyzing the arrangement and cutting pattern of picks in vane and plate, the optimal arrangement of picks in plate is put forward for high lump coal rate.In order to increase lump coal rate, studying the influence of cutting parameters on cutting pattern area A and squareness rateξ, the optimization mathematical model is established taking the maximum of cutting pattern area as objective function. Using Genetic Algorithm of direct comparison-proportion method, the optimization calculation is carried out and the corresponding optimal values of structure and cutting parameters are obtained under the different pick arrangements,and the optimal arrangement of picks in vane is also obtained for high lump coal rate.The structure optimization of shearer drum is conducted under a certain coal property for high lump coal rate. In order to meet the needs for different coal seam properties, the optimization of variable cutting and traction speed is studied. At the same time, the method of recognizing cutting impedance roughly with measured cutting load of shearer is put forward, and adjusting cutting parameters according to this.Aim at the adverse working status and environment condition in mining face underground, the dissertation selects micro-controller S3C44B0X, high speed A/D transformer 40kSPS and Compact Flash (CF) card to constitute an embedded system for measuring cutting load of shearer, and completes the hardware design, software design, anti-detonation design and inherence safety design. The developed system is used in coal mine underground to measure the load spectrum for shearer, the results indicate the system is feasible and practical.The Switched Reluctance Motor (SRM), with the advantages of simple and strong structure, rotor maintenance-free and large torque in low speed, is selected as the power source for variable speed cutting of shearer. The magnetic circuit characteristic of SRM is analyzed by use of the finite element method, providing the theoretical basis for optimization design of SRM structure. The dissertation gives modeling methods of the flux linkage model which can correctly reflect the nonlinear electrical-magnetic characteristics of SRM, and conducts the comparison analysis between optimal and measured flux linkage curves, laying a foundation for selection of SRM modeling methods.In order to increase running reliability of Switched Reluctance Motor Drive (SRD) system, the position sensorless control strategy is proposed and the correlative hardware and software of SRD system are completed. By use of the exciting voltage pulse method to select the start-up phase of SRM, the motor start with non-reversal is solved in practical production field. The experimental platform of 18.5kW SRM is set up. The experimental results verify the correctness of position sensorless control strategy proposed, and the feasibility and reliability of the position sensorless SRD system for shearer are also proved更多还原