摘要
为深入研究和揭示多维振动筛筛面物料运动规律和透筛机理以及设计三自由度混联振动筛,基于机构拓扑结构理论构造了一种全解耦的三自由度混联机构2PRRR-P(2R),作为三自由度振动筛的主体激振机构;运用D-H变换矩阵推导出筛面的运动轨迹方程,并运用ADAMS软件对振动筛进行运动学仿真,验证了机构设计的可行性;基于离散元法对棉籽颗粒群在三自由度振动筛筛面上的筛分过程进行了模拟分析,表明筛面的三维运动能增加颗粒群在X和Y向的抛掷位移,使颗粒群平均透筛时间缩短;试验结果表明,筛面增加X向的振动后,分散度增加约54%,筛分效率增加约46%;筛面增加X向和Y向的振动后,分散度和筛分效率分别增加约152%和68%,比仅增加X向振动时分别增加约62%和15%,试验结果与EDEM仿真结果一致。研究表明,三自由度混联振动筛能实现筛面沿X、Y、Z向的三维独立振动,其自由度、振幅、频率等振动参数调节方便;筛面的三自由度振动利于颗粒物料在筛面上分散,可大幅提高筛分效率。该研究对进一步研究多维振动筛分机理、研制三自由度混联振动筛产品样机等提供了参考。
To further study and reveal material movement rule and penetrating screening mechanism on multidimensional vibrating screen as well as to design a hybrid vibrating screen of three degrees of freedom（3-DOF）, the paper, based on topological structure theory in mechanism, has constructed a complete decoupling 3-DOF hybrid organization of 2PRRR-P（2R） as the main body of vibration mechanism in the 3-DOF hybrid vibrating screen and has designed an experiment prototype of the 3-DOF hybrid vibrating screen. The simulation test of screen movement on the screen surface was carried out and analyzed. Cotton seed particles of ellipsoid were taken as the typical materials. Movement rule of material particle group on the screen surface of the 3-DOF hybrid vibrating screen was analyzed. D-H transformation matrix was used to deduce motion trace equation on the screen surface. The kinematics simulation was carried out with ADAMS software, and the feasibility of the mechanism design has been verified. Based on the discrete element method, the paper used optimal selection of difficult ellipsoid cotton seed particles of ellipsoid that is difficult in screening in agricultural materials as the screening objects, and carried out simulation analysis on screening process of cotton seed particle group on the screen surface of the 3-DOF hybrid vibrating screen. In the simulation test, optimal screen size is 280 mm × 160 mm and contact model between cotton seeds and screen surface belongs to the Hertz model. Set in the rectangle form of 140 mm × 80 mm, particle factory produced 10 000 cotton seed particles and particle generation rate was 5, 000 per second. The simulation time was 8 s. In the experiment, reciprocating motions in Z, XZ and XYZ directions were respectively added on the screen surface. Based on truncation technique, the average values of three-coordinate in borderless particles collision were respectively extracted and the particle group displacement time curve on the screen surface was drawn. Simulation test results
出处
《农业工程学报》
EI
CAS
CSCD
北大核心
2015年第6期49-56,共8页
Transactions of the Chinese Society of Agricultural Engineering
基金
中国博士后科学基金资助项目(2013M540507)
安徽省高校优秀青年人才支持计划项目(R14-3-2Y287)
关键词
农业机械
振动
机构
振动筛
三自由度
三维离散元法
棉籽颗粒群
agriculture machinery
vibrations
mechanisms
vibrating screen
3-DOF
three dimensional discrete element method
cottonseed particle group
