掘进机纵向截割头的运动学分析及简化计算

针对掘进机纵向截割头的不同工作状态,讨论了运动的简化问题,揭示了截割头各工况时的运动过程及速度变化规律,找出了各种情况下磨损最快截齿在截割头所处的位置。这对规划截割头的最佳截割路线,提高截割效率和掘进速度,都具有十分重要的意义。     

截割头缺齿运行对其工作载荷的影响

截割头缺齿运行在现场使用中是很普遍的现象，但由此带来的后果却一直没有引起足够的重视，本文利用建立的截割头载荷的数学模型，采用计算机模拟的方法，对截割头各种缺齿状态下运行时工作载荷的变化及其影响作了分析研究，所得结论对于正确地使用和维护掘进机有一定的指导作用。     

扁截齿失效的有限元应力分析

本文运用有限元法,分别计算分析了扁截齿仅在截割力作用和同时在截割力、焊接残余应力作用及缺焊两种状态下的应力分布。对扁截齿硬质合金头脱落、崩刃及刀杆折断的原因,分别从相当应力及硬质合金头焊面上的张应力、剪应力的分布进行了探讨。     

截齿叶序排布方式对截割头横向载荷的影响

为改善截割头工作时的截割载荷,设计一种基于叶序理论的仿生截割头。论述了叶序参数在截齿安装中的应用,并绘制截齿排列展开图。采用EDEM软件进行离散元法仿真,从横向截割载荷方面对两种截割头的截割性能进行比较。多组仿真模拟验证叶序角对截割头截割载荷的影响。结果表明:在工作条件相同的情况下,相邻截齿之间叶序参数选择的不同,截割头截割载荷会有不同程度的波动;合理的叶序参数能明显减小截割载荷;当相邻截齿夹角从37°变为45.833°时,截割载荷从34411N降低为11281.9N。     

横向截割头切屑图人机界面系统的设计与模拟研究

建立了以截齿崩落线方程和交点坐标方程为代表的切屑图的数学模型,基于MATLAB／GUI设计了横轴式掘进机截割头切屑图的人机界面系统。利用该系统,通过在界面上输入截割头的相应参数,就能模拟掘进机截割不同煤岩时、不同工况参数下的横轴式掘进机的切削过程和切屑图。通过以国产某型掘进机为例进行模拟,获得了该掘进机在不同参数下的切屑图,根据切屑图比较分析了截齿的受力状态、切屑厚度与截割粉尘量以及截割阻力的大小,为提高截割头设计水平、研究横轴式掘进机的截割过程,改善该型掘进机的截割性能奠定了基础。     

部分断面掘进机截割头的改进设计

针对在中硬煤岩工作面中掘进机截割头存在的一些问题,对载割头进行了改进设计,并对改进前后掘进机的截割性能和载荷特征作了分析比较。结果表明,改进后的截割头可明显改善机器的工作性能和效率。     

悬壁掘进机截割功率和运动参数的选择

本从保持截割头较高的截割能力、良好的截割工况和较低的截割能耗的观点出发，分析了悬臂掘进机的截割功率、截割速度和牵引速度的合理范围和匹配关系。     

悬臂掘进机截割头牵引速度和牵引力的变化规律

本根据悬臂掘进机工作机的液压回转装置，导出了截割头纵向与横向牵引速度和牵引力的表达式，分析了在采用不同的液压回转装置时，截割头牵引速度和牵引力的变化规律。     

半煤岩巷掘进机截割过程的计算机模拟

针对截割头载荷的特点及掘进机的工作性能,通过计算机模拟,掌握了半煤岩掘进机的截割过程及力学性能,为该型掘进机的研究和改进提供了可靠的依据。     

自磨锐截齿转动装置的设计与研究

针对现有截齿磨损严重现象,提出自磨锐截齿的结构设计,通过转动装置实现在截割过程中自转,因此转动装置就成为截齿的关键部件。运用ANSYS/LS-DYNA对该转动装置进行瞬态显式动力分析,验证转动装置的可行性。最终得到截齿正反转的转动装置,实现截齿自磨锐(工作中自转),延长截齿使用寿命。     

Modeling and simulation of crushing process of spiral mining head

1 INTRODUCTIONThe research of mining deep seabed cobalt-richcrust is a hotspot of international oceanology[1].Based on the mining manganese nodule ,lots of re-searches on mining cobalt crust have been madedeeply and many kinds of methods ,such as thei m-proved CLB, mining vehicle +lifting system +surface supporting ship have been put forward.Mining vehicle consists of collecting machine ,tracked treading machine and spiral mininghead[2 ,3].The first step of mining cobalt crust is tocrush…     

Optimal control of cobalt crust seabed mining parameters based on simulated annealing genetic algorithm

Under the condition of the designated collection ratio and the interfused ratio of mullock,to ensure the least energy consumption,the parameters of collecting head (the feed speed,the axes height of collecting head,and the rotate speed) are chosen as the optimized parameters.According to the force on the cutting pick,the collecting size of the cobalt crust and bedrock and the optimized energy consumption of the collecting head,the optimized design model of collecting head is built.Taking two hundred groups ...     

Study on pick arrangement of shearer drum based on load fluctuation

According to the coal or rock cutting theory, a mechanical model and computing formula for a pick and the drum load fluctuation model were established in order to obtain relationships between pick arrangements and drum fluctuation loads, drum rotary speeds and haulage speeds. Based on a minimum load fluctuation, an optimal mathematical model was established for drum pick arrangements. The effects of pick arrangements (including punnett square, sequence, aberrance Ⅰ and Ⅱ) on the drum load fluctuation coefficient are discussed. The relationships between the pick arrangements of the drum with different start vanes and the cutting load fluctuation coefficient, the drum rotary speed and haulage speed were also studied. The results indicate that the punnett square arrangement has a smaller cutting load fluctuation coefficient than other forms of arrangement and the drum with the 4-start vanes has the smallest coefficient. The drum rotary speed and haulage speed are affected not only by pick arrangements, but also by the number of vanes.     

Method to determine installing angle of conical point attack pick

In order to obtain the determining method of the installing angle and decrease the performance indices (cutting force and wearing rate) of the pick, the relationships among the installing angles (impact angle, inclination angle and the skew angle) were studied, and the static model of installing angles of the pick was built. The relationships among the impact angle, the tip angle of pick and the kinematics parameters of the pick were built, too. Moreover, the mechanic models of the maximum clearance angle and the wearing angle of the pick were set up. To research the relationships of the installing angles and the change law of the wearing angle along with the kinematics parameters, the simulation was done. In order to verify the correctness of the models, the cutting experiments were done by employing two picks with different pick tip angles. The results indicate that, the cutting force is the smallest when the direction of the resultant force of pick follows its axis, and the relationship derived among the installing angles should be satisfied. In addition, to decrease the cutting force and the wearing of the pick, the tip angle of pick should not be larger than the half of the difference between the minimum wearing angle and the impact angle of the pick, and the clearance angle must not be less than zero.     

Model test of the cutting properties of a shearer drum

According to similarity theory, we carded out a dimensional analysis of the shearer drum correlation parameters and built similarity criteria. Based on these, similarity models of shearer drums were developed. Simultaneously, based on an estab-lished cutting testbed of the coal and rock, cutting tests of different pick arrangements of the drum models were carried out, where the compressive strength of the analogous cutting material was 2.48 MPa and the drum rotary speed 67.5 r/min. The variance, the mean values, maxima and mean maxima of the torque load were analyzed for different type drum models. Moreover, the relation-ships between the type of pick arrangements and the cutting lump coal percentage were studied. The results indicate that the load fluctuation of the sequence drum is larger than that of the punnett square drum in the cutting process and the lump coal percentage and economic benefits of the sequence drum are inferior to the punnett square drum. We conclude that the punnett square drum is superior to the sequence drum.     

采煤机切割时作用力的分析与探讨

采煤机切割机理的研究是当今非常重要的课题,对提高采煤机生产率,降低能耗,减少刀齿损耗都具有重要意义。本文对煤炭切割过程、切割机理进行了分析。对于截齿切割时的影响因素进行了分析与研究。提出了采煤机单齿的受力状况及计算公式。     

隔振装置中振动功率流的测量研究

以舰舶柴油机双层隔振装置为对象,研究了隔振装置中的振动功率流,用不同的振动功率流测量方法测量了通过隔振器传到上,下层质量和流入弹性基础中的振动功率汉,不同的测量方法得到了类似的测量结果,可以利用隔振器上,下端的加速度互谱密度和隔振器的传递视在质量测量通过每个隔振器传递的振动功率流,也可以通过各接触点的有效导纳和加速度测量通过各接触点的传递的振动功率流。     

采煤机滚筒不均匀运动时截齿瞬时切削厚度的算法

给出了采煤机螺旋滚筒不均匀运动时截齿瞬时切削厚度计算的数学模型和程序框图。本算法逻辑性强、结构紧凑，可在微机上实现。