An optimized design method of the ratcher mechanism in the multi - step belt conveyer with intermittent movement is presented . a practical design example is given 摘要提出了一种多步距间歇运动的带式输送机棘轮机构的优化设计方法，并给出了设计实例。
The strata behavior rule of longwall face with individual props in shallowly buried coal seam covered with thick soil was summarized 实验和观测表明，尽管其上覆岩层的力学强度比较小，煤层埋深浅，但工作面初次来压步距大，矿山压力显现剧烈，周期来压台阶下沉量大。
The test results show that the drawing interval of 1 . 5 m is helpful for controlling dead - unconsolidated thin sandstone of coal seam roof and reduce sand ratio of drawn top - coal 试验结果表明，放煤步距采用三采一放有利于控制顶板极松散细砂岩，降低放出顶煤的含砂率。
The effects of different drawing interval and top - coal fragmental size on flow character of coal - gangue and sand , and on mixed degree of coal and gangue were analyzed during drawing top - coal 分析了不同放煤步距、顶煤块度对放煤过程中煤矸砂流动形态、混矸程度的影响。
The method which good merits of high - fitting - accuracy and simplicity , can be used to subdivide the equal - stride - angle and to improve torque - frequency characteristics at low frequency 该算法简单，拟合准确度高，可实现步距角的等步距细分，能有效地改善低频起动矩频特性。
Trapezoid very similar design suitable for a multipolar structure , not only reduced the permanent magnetism suggests the step away from the electrical kok , and high utilization of materials ; 3 2 .梯形爪极设计适合于多极结构，不仅减小了永磁步进电机的步距角，而且材料利用率高
Popular point of view : when receiving step drive to a pulse signal , it driven by a step in the direction of the electrical equipment of a fixed point that is , step away from kok 通俗一点讲：当步进驱动器接收到一个脉冲信号，它就驱动步进电机按设定的方向转动一个固定的角度即步距角。
It was found that comparing with the case without dirt band the periodic weighting distance , median roof moving coefficient and support resistance all increased to different extent because of the influence of dirt band 发现由于夹矸的影响，与不含夹矸层工作面相比，其周期来压步距、平均动压系数和支护阻力都有不同程度的增大。
If increasing drawing interval , the movement and flow range of top coal will enlarge , and the velocity gradient on flow cross - section will diminish , so that it is good for controlling the flow rate of thin sand among loose top coal 研究表明，加大放煤步距，顶煤运移流动的范围变大，流动断面内速度梯度变小，有利于控制细砂的下窜速度。
The debugging comprises open loop and closed loop debugging . the result shows that the controlling system works steady , quickly and precisely . the actuator can achieve the minimal step distance of less than 0 . 2 urn 控制系统的安装调试包括开环和闭环调试，调试结果表明，致动器控制系统工作稳定，反映速度快，可控精度高，可以达到了设计要求的步距小于0 . 2 m指标。
