摘要
环模制粒机因其高效率、低能耗等优点广泛应用于饲料、生物质能源等领域,而目前的环模制粒机振动剧烈,尤其是有转子偏心时环模会受到强烈的振动冲击,严重减小环模的使用寿命。因此对转子偏心下环模制粒机的振动特性进行了分析并对其主要结构进行优化。基于粉体挤压成型规律以及环模与压辊挤压成型规律,建立了考虑压辊表面正向静摩擦力作用下的环模与压辊之间准确的相互作用力模型,并对压辊与环模有相对位移时其相互作用力的变化规律进行建模和分析。基于多体动力学软件建立了转子偏心下环模制粒机的动力学仿真模型,分析转轴、主轴以及挤压力的振动特性,并对主轴、支撑架以及转轴轴承的结构或位置参数进行分析和优化。研究结果表明：压辊与环模之间相互作用力与相对位移之间近似成线性关系;主轴上转轴支撑段直径应大于直径;主轴直径增大有利于转轴振动幅值减小但是会增大挤压力幅值,将压辊底座通过柔性杆与主轴连接可在减小转轴振动的同时大幅减小挤压力的振动;支撑架的径向刚度应大于1×10^7N/m,弯矩刚度应大于1×10^5N·m/deg;转轴轴承间距存在与轴承刚度相关的最优值,且最优轴承间距会随着轴承刚度增大而减小。
Ring die pellet mills have been widely used in the biomass-energy,feed industry,chemical industry because ring die pellet mills have a series of advantages,such as a high forming rate,lower pollution,energy-efficient and etc. However,the existing ring die pellet mills have serious vibration issue,especially for the pellet mills with rotor eccentricity. The vibration of ring dies severely shortens the ring die life. According to the powder pressure-density relationship and the pressure distribution in deformation area,the accurate interaction force between rollers and ring dies was figured out with considering the positive static frictional force on the roller surface. The change law of the interaction force between the roller and the ring die with relative displacement was also discussed. A dynamic simulation model of ring die pellet mills with rotor eccentricity was set up by using the multi-body software. Dynamic simulations were performed to study the vibration of revolving shaft,dead axle,and compaction force. The results reveal that the interaction force between the roller and the ring die varies linearly with the relative displacement between the roller and the ring die. The revolving shaft support segment of the dead axle should be stouter than the frame support segment. Increasing the dead axle diameter will lead to reduced vibration of the revolving shaft but increased compaction force. A flexible bar was used to fix rollers to the dead axle to solve the problem. The simulation shows that the optimization can dramatically reduce the vibration of the compaction force. The radial stiffness of frames should be kept above 1 × 10^7 N / m. The bending rigidity of frames should be kept above 1 × 10^5 N·m / deg. There is an optimum value for the bearing spacing parameter at different stiffness of bearings of the revolving shaft.
出处
《振动与冲击》
EI
CSCD
北大核心
2016年第24期59-65,95,共8页
Journal of Vibration and Shock
基金
江苏省自然科学基金项目(BK2011706)
江苏省产学研联合创新资金-前瞻性联合研究项目(BY2012023)
关键词
环模制粒机
转子偏心
动力学仿真
粉体挤压
振动
ring die pellet mill
rotor eccentricity
dynamic simulation
powder compaction
vibration
