1、本论文以采煤机截煤理论为依据,建立煤岩特性数学模型、螺旋滚筒模型、镐型截齿模型以及截割载荷模型,研究了煤的性质、镐型截齿参数、螺旋滚筒结构参数和运动参数对螺旋滚筒扭矩、比能耗、块煤率的影响,进一步得到了相关参数间的表达式和规律; 以理论数据为依据,以MATLAB为工具,对截割载荷进行了分析,得到了截齿载荷变化的波形和随煤岩性质不同的变化趋势;同时,描述了切割破碎煤负载变化滚筒的过程中,破碎煤模型和动态力学模型滚筒建立切割煤岩的基础上得到采煤机的约束。本论文对单齿载荷模型和单齿破煤负荷分布的分析,在此基础上的理论,采用随机理论,建立了单齿随机载荷的典范。在直角坐标系下,对滚筒采煤机滚筒受力进行理
2、论分析,进而建立了随机三向力系和随机三向力矩系的模型,以MATLAB软件做为研究平台,编写了每个随机载荷的理论模拟程序。在螺旋滚筒基本尺寸给定和特定煤层形式情况下,以滚筒的截齿和螺旋叶片布置形式为设计变量,以降低载的荷波动为目的,并利用MATLAB进行优化计算。关键词:滚筒式采煤机;截割理论;采煤机滚筒;滚筒截割性能;载荷;AbstractAt present,shearer is the uppermost work equipment in fully-mechanized coal working face ,the screw drum is shearers pivotal part
3、 and working framework,Its capability stand or fall decide shearers work performance and production efficiency.so it is significant to establish pick screw drums load model,simulate screw drums load, and optimize design for parameters of the screw drum.With regard to this, the theoretical analysis,
4、simulation and experiment are combined to investigate the cutting performance shearer drum and dynamic characteristic of the cutting system in this thsis . According to the shearer cutting theory, Mathematical Model for the coal characteristic , the drum, the pick and the cutting load are built. The
5、 influence of the coal characteristic, pick structure parameters and drum structure parameters on the drum cutting torque, cutting specific consumption and lump coal percentage are investigated, and the relationship expression and variation laws are acquired.According to the experiment date and talk
6、ing the wavelet theory as guidance . Regard MATLAB software as the platform , the detail wave of the load change and the change trend of load along with the coal characteristic change are obtained. And the influence laws of the coal-rock interface form on the cutting system frequency are acquired ,
7、too.the load variation is described . Based on the built constitutive model of catastrophe and dynamic model , the cusp catastrophic model of the drum cutting coal is established,and the rigidity and energy conditions are acquired for the shearer cutting availably. On the foundation of the theory wh
8、ich is about the single picks average load, analyzed loadss probability distribution and relevance when a single pick cuts various coal rock, on this basis, utilizing the stochastic process theory, set up the mathematical model about the single picks stochastic loads. Under the coordinate of Descart
9、es, analyzed the loads of continuous mines cutting drum, and set up the mathematical model about drums stochastic strength and moment which include three direction. Regard MATLAB software as the platform, write each stochastic loadss simulation programme. Analyzed the spectrum of simulated load in f
10、requency field, time field and amplitude field ,studied loads desity of probability distribution, since(or mutual) relevance, since(or mutual) desity of the power spectrum. And analyzed each parameters influence to base wave frequency and other main frequency of loads. Set up the fuzzy optimize mode
11、ls which regard reducing the loads fluctuation as the goal function, and regard assigned form of pick and blade , rotational speed of cutting drum, swing speed of rocker arm as designed variable, and optimized the parameters using corresponding optimize function in MTALBAs optimization toolbox.Keywo
12、rds: shearer; cutting theory; shearer drum; drum cutting performance1绪论1.1滚筒式采煤机概述 机械化采矿工程年中的重要设备是螺旋滚筒式采煤机,螺旋滚筒式采煤机是典型的机电和液压系统,直接决定着采煤的效率,有大质量(20200T) 、大功率(3002400kW)和高产量(1001000万吨/年)等的特点,在机械化采矿设备中,使用量占到 90%以上。螺旋滚筒式采煤机划分为单滚筒和双滚筒采煤机,单滚筒采煤机只适用在薄煤层中,且现在使用量稀少,因此本论文所要讲述的滚筒采煤机指的是双滚筒采煤机。双滚筒螺旋采煤机能免开缺口、适应复杂的
13、顶条件和底板条件,适用于各种性质煤矿,能割硬质煤;采高大,调高较为方便,在斜煤层中其采高为 0.656.0m,采用无链牵引时能在 3554的条件下工作。可根据煤层厚度来选择螺旋滚筒的规格尺寸,极薄煤层0.30.5m不可采,薄煤层0.51.3m 采用滚筒直径为6001000的滚筒,中厚煤层1.33.5m采用直径为10003000的滚筒,厚煤层3.58.0 m,特厚煤层大于8.0 ,采用直径为30003500的滚筒。采煤机选用具有上述好处,滚筒式采煤机很快得到了普及和推广,并在性能和结构方面继续改进和日趋完善。螺旋滚筒式采煤机的结构如图 1-1 所示,包含四大部分:中间箱、牵引机构、行走机构、截割
14、机构。中间箱为采煤机的动力部分与控制部分。牵引机构是行走机构的动力源与传动部分,牵引方式的不同导致动力源的不同,主要是电牵引和液压牵引两种方式,依靠固定箱下边滑靴与布置在工作面上的输送机轨道相接触,并被支撑起来。行走机构利用牵引电动机或者液压马达输出的动力经过减速后,传到1- 中间箱 2-牵引部 3-行走部 4-截割部图1-1 采煤机结构图行走箱行走轮,和输送机上销轨啮合,使滚筒式采煤机行走,可实现无极变速,在破煤过程中随着截割煤层的性质不同进一步调节牵引速度。截割机构包括摇臂与滚筒,摇臂起传动、减速、调节采高的作用,螺旋滚筒转动直接作用在煤壁上,依靠安装其上的镐型截齿破煤,利用叶片将截割下来
15、的煤送到和采煤机配合的输送机上。在以上采煤机的四大机构中,截割机构的螺旋滚筒是滚筒采煤机的工作机构,因而直接作用于煤层,工作条件很恶劣,因此,截割性能的优劣直接影响螺旋滚筒采煤机的使用寿命与截割性能,并对煤矿企业的效益产生直接影响。采煤机螺旋滚筒包括端盘、螺旋叶片、截齿、齿靴、齿座、筒毂和喷嘴七个部分,如图 1-2 所示。图1-2 采煤机螺旋滚筒1.2国内外采煤机研究现状20世纪中后期,英国和前苏联前后对滚筒采煤机的螺旋滚筒作了技术改造,一是螺旋滚筒能在使用过程中调高,解决对煤层存方式的适应性;二是把圆形筒体改成螺旋叶片截割滚筒,大大地提高了装煤的效率。这次改造就给螺旋滚筒采煤机奠定了现代化采煤机械的基础。90当前国内外使用的采煤机主要是能调高的双滚筒式采煤机,经过改造的滚筒采煤机,可追溯到长壁采煤法中的采煤机,前期用于煤底部掏煤槽的采煤机。最早的螺旋滚筒式采煤机是在采煤机的基础之上,将减速箱部分改装成安一根水平轴与截割滚筒而演化形成的。这种螺旋滚筒式采煤机与刮板输送机配套,奠定了矿山开采机械进步的基础。早期的螺旋滚筒采煤机有两方面坏处,第一:采煤滚筒安装高度不能在使用中调节 (固定滚筒),对煤层厚度适应性较差;第二:破煤滚筒的装煤效果不佳(圆形
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