【摘要】 托辊接触力是圆管带式输送机托辊结构设计的关键参数,工程设计中基于输送带成形力、物料与输送带重力近似计算托辊组接触力,并将其作为单个托辊接触力的设计依据,使托辊接触力误差较大。为提高托辊接触力的计算精度,得到托辊接触力的计算方法,将托辊接触力分解为与物料重力、输送带成形力、输送带重力相关的3个分量,同时考虑托辊组中6个托辊的不同位置,分别研究各托辊接触力中3个分量,最终得到托辊接触力计算式。以管径为150 mm的圆管带式输送机直线段为研究对象,具体研究过程如下:首先,研究了物料因素对托辊接触力的影响,基于有限元法建立了输送带-托辊动力学模型,考虑8组不同物料填充率下各托辊接触力的变化规律,分析得到各托辊承受物料重力的占比,当物料填充率大于50%时,下方两侧托辊承受33%～34%的物料重力,最下方托辊承受约60%的物料重力;其次,基于输送带-托辊动力学模型,分别考虑承载5组不同密度的物料,分析得到物料密度对托辊承受物料重力的占比影响较小,可忽略不计;基于上述物料因素分析,确定了托辊接触力中物料重力分量的计算式。然后,研究了输送带重力、输送带成形力对托辊接触力的影响,分别建立了只考虑输送带成形力和只考虑输送带重力的2种输送带-托辊动力学模型,分析得到下方两侧托辊承受约32%的输送带重力,最下方托辊承受约70%的输送带重力;下方5个托辊受输送带成形力作用相近,最上方托辊受输送带成形力作用最大,约为下方5个托辊平均值的1.49倍。综合托辊接触力中3个分量,得到各托辊接触力的计算式。最后,通过实验测试了不同物料填充率下的托辊接触力,验证了托辊接触力计算式,其计算精度较高。更多还原

【Abstract】 The roller contact force is a key parameter for the roller structure design of pipe conveyor.In the engi-neering design,the total contact force of roller group is estimated roughly by calculating the sum of the forming force of belt,the gravity of material and the gravity of the belt between two roller group.The total contact force multiplied by empirical safety factor is regarded as the structure design basis of single roller.The roller contact force is not accurate enough.In order to improve the calculation accuracy,the contact force is decomposed into three components related to the gravity of material,the forming force of belt,and the gravity of belt.It is also calculated separately considering the difference in the position of six rollers in the roller group.The straight section of a pipe conveyor with a diameter of 150 mm is taken as an example to study contact force,and the specific research process is as follows:firstly,the influence of material factors on the contact force is studied by the dynamic model of belt-roller which is based on the finite element method.The proportion of material gravity on each roller is obtained by the variation law of contact force under eight material filling rates.The result shows that when the material filling rate is greater than 50%,the rollers on lower side are subjected to about 33% to 34% of material gravity,and the bottom roller is subjected to about 60% of material gravity.Secondly,the variation law of contact force under five material densities is modeled by dynamic model.It shows that the influence of density on contact force is weak and can be negligible.So the calculation formula of the material gravity component is obtained based on above analysis.Thirdly,the effects of gravity of belt and forming force of belt on the contact force are studied.Two belt-roller dynamics models of belt-roller are established,which are only considered the forming force of belt and the gravity of belt respectively.The result shows that the rollers on the lower side are subjected to about 32% of belt gravity,and the bottom roller is subjected to about 70% of belt gravity.The forming force component of the belt on the lower five rollers are close,and the top roller is subjected to the largest forming force component of belt,which is about 1.49 times than the average value of lower five rollers.The calculation formula of contact force of each roller is obtained by combining with three components of contact force.更多还原