重载链输送装置传动特性研究及关键结构强度分析

发布时间：2018-03-19 17:29

本文选题：多边形效应　切入点：U型滑道约束　出处：《天津理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：链传动作为一种在机械传动中重要的运动传递方式,因其经济可靠及良好的传动性能被广泛的应用于各种机械传动系统中,如运输、采矿、冶金、军事等。但是,在输送机构中使用链传动时,由于输送机低速重载的特点,带有松边的传统型传动链已经不能满足工程实际的要求。采用滑道约束的输送机,在给定的区域内实现携带负载数量的最大化,并能显著地提高输送系统的可靠性,可以有效地改善输送装置的承载能力。本课题研制一台特殊的重载链输送装置样机,用于普通链传动难以实现的重载输送链的场合。本课题研究的主要内容如下:(1)分析了传统的无滑道约束的大节距链传动的运动特性。其速度波动较大,运动稳定性较差,同时链条的紧边也不能保持时刻的张紧状态。通过对输送链施加滑道约束,对运动特性进行改善。(2)为了有效的利用实际空间,设计了U型滑道约束链传动。描述了一个周期内销轴运动轨迹,实现其连续运动。进而推导出链节中心的运动轨迹,最终得到链节的内外约束滑道。对U型滑道及其它零部件,如链轮,销轴,链节,负载仓,连接杆等,进行了设计及UG软件的三维参数化建模,装配和运动学仿真。(3)对U型滑道约束输送链模型进行简化,使主、从链轮相啮合的链节与链轮固接,其余链节绕其对应滑道中心转动。链节简化成集中质量,相邻链节之间用弹簧、阻尼器相互连接。在简化模型的基础上建立了基于拉格朗日的运动学模型,并进行了微分方程的推导。运用MATLAB软件的ode45函数进行计算,求解主、从链轮及各链节的振动情况。(4)把建立的三维参数化模型导入RecurDyn软件中,充分利用其基于相对坐标系建模和递归求解法,成功的解决了动力学碰撞问题。对本模型中链节携带全部负载和极限负载的情况下,仿真分析从动链轮的速度、加速度波动情况,链节与链轮的啮合冲击载荷,链节在滑道内运动的冲击载荷。(5)对U型滑道进行了有限元分析,分析其在最大受力情况下的应力、应变。对机架进行了有限元模态分析,求解其固有频率及其振型图。
[Abstract]:Chain transmission, as an important mode of motion transmission in mechanical transmission, is widely used in various mechanical transmission systems, such as transportation, mining, metallurgy, military and so on, because of its economical, reliable and good transmission performance. When using chain drive in conveying mechanism, because of the characteristic of low speed and heavy load of conveyor, the traditional transmission chain with loose edges can no longer meet the practical requirements of engineering. To maximize the number of loads carried in a given area and to significantly improve the reliability of the conveying system, the load-carrying capacity of the conveyer can be effectively improved. In this paper, a prototype of a special heavy-load chain conveyer is developed. The main contents of this paper are as follows: (1) the kinematic characteristics of the traditional large-pitch chain drive without sliding path constraints are analyzed. The velocity fluctuates greatly and the motion stability is poor. At the same time, the tight side of the chain can not maintain the state of tension at the moment. In order to make effective use of the actual space, the movement characteristics of the chain are improved by imposing sliding path constraints on the conveyor chain. The U-type sliding path constrained chain drive is designed, and the movement path of a periodic pin shaft is described to realize its continuous motion. Then, the motion trajectory of the chain node center is deduced, and the internal and external constrained slide path of the chain joint is obtained. For U type slide track and other parts, For example, sprocket, pin shaft, chain joint, load bin, connecting rod, etc., the design and 3D parameterized modeling of UG software, assembly and kinematics simulation. From the chain joint engaged by the sprocket to the sprocket, the rest of the link rotates around the center of the corresponding slide track. The link is simplified into a concentrated mass, and the adjacent links are connected with a spring. The dampers are connected to each other. Based on the simplified model, the Lagrangian kinematics model is established, and the differential equation is derived. The ode45 function of MATLAB software is used to calculate and solve the main problem. According to the vibration of the sprocket and each link, the 3D parametric model is introduced into RecurDyn software, and the model based on relative coordinate system and recursive solution method are fully used. The dynamic collision problem is solved successfully. In this model, the velocity and acceleration fluctuation of the driven sprocket, the meshing impact load between the link and the sprocket are simulated and analyzed under the condition that the link carries all the load and the limit load. The finite element analysis of the U-type slide track is carried out, and the stress and strain under the maximum force are analyzed. The finite element modal analysis of the frame is carried out, and the natural frequency and its mode pattern are solved.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TH132.45

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