Reliability and wear resistance of cutting picks play a significant role in coal mine exploitation with coal shearers.Tool bit separation,blade breaking,severe erosion of the cutting body and fatigue fractures are the...Reliability and wear resistance of cutting picks play a significant role in coal mine exploitation with coal shearers.Tool bit separation,blade breaking,severe erosion of the cutting body and fatigue fractures are the main reasons for failure of cutting picks.We carried out carburization on a 30CrMnMo alloy to synthesize a new cutting pick material with improved mechanical properties and high wear resistance.The results indicated that carburization can effectively strengthen the surface of the 30CrMnMo alloy by forming a thick carburized layer and thus significantly improve the surface hardness and wear resistance.In addition,the excellent toughness of 30CrMnMo alloy as a substrate of cutting picks can prevent brittle ruptures and fatigue fractures under high impact stress conditions.The significant decrease in both frictional coefficient and rate of erosion of this carburized 30CrMnMo alloy suggests that this alloy is a potential material for cutting picks of coal shearers after rational carburization.展开更多
In order to determine the influence of shearer's cutting and neighboring shields' advance on the support resistance variation, leg pressure data of all 235 shields in the panel LW61 of Cumberland coal mine wer...In order to determine the influence of shearer's cutting and neighboring shields' advance on the support resistance variation, leg pressure data of all 235 shields in the panel LW61 of Cumberland coal mine were analyzed. The results show that the relationship between the leg pressure increment and the distance from shield to front drum of shearer is a quadratic function and that the higher leg pressure increment before shield advance tends to be related to adverse roof conditions. In addition, the three proposed leg pressure increment-related parameters and the three traditional parameters(time-weighted average pressure, setting pressure, and final pressure) of approximately 32000 shield supporting cycles were calculated by a self-developed software package to analyze the correlation between them. The results show that there is a powerful connection between them, and that the three proposed leg pressure increment-related parameters could be used as the indexes to evaluate the interaction between shields and the roof, and to identify the periodic weighting.展开更多
In order to realize the memory cutting of a shearer, made use of the memorizedcutting path and acquisitioned cutting parameters, and realized the teaching and playbackof the cutting path.In order to optimize the memor...In order to realize the memory cutting of a shearer, made use of the memorizedcutting path and acquisitioned cutting parameters, and realized the teaching and playbackof the cutting path.In order to optimize the memory cutting path of a shearer, took intoaccount the constraints of coal mining craft, coal quality and the adaption faculty of coalmining equipments.Genetic algorithm theory was used to optimize the memory cutting ofshearer and simulate with Matlab, and realized the most valuable mining recovery rate.The experimental results show that the optimization of the memory cutting path of ashearer based on the genetic algorithm is feasible and obtains the most valuable memorycutting path, improving the ability of shearer automatic cutting.展开更多
Cutting tests were done using a test bed designed to measure pick cutting forces when cutting coal and rock.The test equipment has a drum with two starting helical vanes.Cutting forces on a pick were measured as a fun...Cutting tests were done using a test bed designed to measure pick cutting forces when cutting coal and rock.The test equipment has a drum with two starting helical vanes.Cutting forces on a pick were measured as a function of coal compressive strength,pick carbide tip diameter and the cutting depth per drum revolution.The results show that the cutting force is linearly related to the compressive strength.The relationship between the cutting force and both the carbide tip diameter and the cutting depth are exponential.Fluctuation in the cutting force does not increase with coal compressive strength but it has a linear relationship to tip diameter.A plot of cutting force fluctuations versus the cutting depth follows a sigmoidal curve.Based on the analysis of these test results a theoretical basis is supplied for design and effective use of shearer drums.展开更多
采煤机截割滚筒能耗高、效率低的问题日益突出,急需对其开展节能增效研究。因此,基于发明问题解决算法(Algorithm for Inventive-Problem Solving,ARIZ),提出一套采煤机截割滚筒节能方案,包括优化滚筒结构设计、改进驱动机构、智能控制...采煤机截割滚筒能耗高、效率低的问题日益突出,急需对其开展节能增效研究。因此,基于发明问题解决算法(Algorithm for Inventive-Problem Solving,ARIZ),提出一套采煤机截割滚筒节能方案,包括优化滚筒结构设计、改进驱动机构、智能控制策略、回收利用等。通过理论分析与仿真,优化截齿布置参数和滚筒体结构,提出电液混合驱动和自适应智能控制方法,给出热能回收和振动能量收集方案。试验结果表明,该节能方案在不同工况下的能耗降低15%以上,振动降低30%以上,具有显著的节能效果和良好的动态特性。展开更多
基金the Youth Foundation of China University of Mining & Technology (No.2009A056)the Tribology Science Fund from State Key Laboratory of Tribology at Tsinghua University (No.SKLTKF08A01)+1 种基金the National Natural Science Foundation of China (Nos.50905180 and 51005234)the National Science and Technology Pillar Program in the Eleventh Five-Year Plan Period (No.2008BAB36B02)
文摘Reliability and wear resistance of cutting picks play a significant role in coal mine exploitation with coal shearers.Tool bit separation,blade breaking,severe erosion of the cutting body and fatigue fractures are the main reasons for failure of cutting picks.We carried out carburization on a 30CrMnMo alloy to synthesize a new cutting pick material with improved mechanical properties and high wear resistance.The results indicated that carburization can effectively strengthen the surface of the 30CrMnMo alloy by forming a thick carburized layer and thus significantly improve the surface hardness and wear resistance.In addition,the excellent toughness of 30CrMnMo alloy as a substrate of cutting picks can prevent brittle ruptures and fatigue fractures under high impact stress conditions.The significant decrease in both frictional coefficient and rate of erosion of this carburized 30CrMnMo alloy suggests that this alloy is a potential material for cutting picks of coal shearers after rational carburization.
基金provided by the National High Technology Research and Development Program of China(No.2012AA062100)the Program for New Century Excellent Talents in University of China(No.NCET-10-0770)
文摘In order to determine the influence of shearer's cutting and neighboring shields' advance on the support resistance variation, leg pressure data of all 235 shields in the panel LW61 of Cumberland coal mine were analyzed. The results show that the relationship between the leg pressure increment and the distance from shield to front drum of shearer is a quadratic function and that the higher leg pressure increment before shield advance tends to be related to adverse roof conditions. In addition, the three proposed leg pressure increment-related parameters and the three traditional parameters(time-weighted average pressure, setting pressure, and final pressure) of approximately 32000 shield supporting cycles were calculated by a self-developed software package to analyze the correlation between them. The results show that there is a powerful connection between them, and that the three proposed leg pressure increment-related parameters could be used as the indexes to evaluate the interaction between shields and the roof, and to identify the periodic weighting.
基金Supported by the High-Tech Research and Development Program of China(2008AA062202)Fok Ying Tung Education Foundation(114003)New Teacher Foundation for the Doctoral Program of Ministry of Education(20070290538)
文摘In order to realize the memory cutting of a shearer, made use of the memorizedcutting path and acquisitioned cutting parameters, and realized the teaching and playbackof the cutting path.In order to optimize the memory cutting path of a shearer, took intoaccount the constraints of coal mining craft, coal quality and the adaption faculty of coalmining equipments.Genetic algorithm theory was used to optimize the memory cutting ofshearer and simulate with Matlab, and realized the most valuable mining recovery rate.The experimental results show that the optimization of the memory cutting path of ashearer based on the genetic algorithm is feasible and obtains the most valuable memorycutting path, improving the ability of shearer automatic cutting.
基金Projects 2008AA062202 supported by the Hi-tech Research and Development Program of ChinaCX08B_041Z by the Innovation Foundation of Jiangsu Graduate Students
文摘Cutting tests were done using a test bed designed to measure pick cutting forces when cutting coal and rock.The test equipment has a drum with two starting helical vanes.Cutting forces on a pick were measured as a function of coal compressive strength,pick carbide tip diameter and the cutting depth per drum revolution.The results show that the cutting force is linearly related to the compressive strength.The relationship between the cutting force and both the carbide tip diameter and the cutting depth are exponential.Fluctuation in the cutting force does not increase with coal compressive strength but it has a linear relationship to tip diameter.A plot of cutting force fluctuations versus the cutting depth follows a sigmoidal curve.Based on the analysis of these test results a theoretical basis is supplied for design and effective use of shearer drums.
文摘采煤机截割滚筒能耗高、效率低的问题日益突出,急需对其开展节能增效研究。因此,基于发明问题解决算法(Algorithm for Inventive-Problem Solving,ARIZ),提出一套采煤机截割滚筒节能方案,包括优化滚筒结构设计、改进驱动机构、智能控制策略、回收利用等。通过理论分析与仿真,优化截齿布置参数和滚筒体结构,提出电液混合驱动和自适应智能控制方法,给出热能回收和振动能量收集方案。试验结果表明,该节能方案在不同工况下的能耗降低15%以上,振动降低30%以上,具有显著的节能效果和良好的动态特性。