外文资料与中文翻输送机

外文资料与中文翻译外文资料：Research on Dynamic Tension for Belt Conveyor with Constant Force Automatic TakeUp AssemblyAbstract：The article Provides a dynamic model for belt conveyorBased on the driveforce of conveyor，takeup tension of takeup assembly，gravity of conveyor belt and material，and friction between belt and idlers，it gives a viscoelastic dynamic equation for conveyor belt It presents a calculation method of analytic solution to both viscoelastic dynamic equation and geometric dynamic equation when automatic take-up assembly is applied to belt conveyor.The article also makes a study of design method of limiting and eliminating the conveyor belts elasticvibrationKey words：belt conveyor；dynamic equation；displacement calculation；conveyor belt tension calculation；limiting vibration impact1 IntroductionFrom the beginning of the 1 960s，many countries，such as Soviet Union，Germany， Australia，America，Poland and so on，have roundly researched into the dynamics problems of belt conveyor，including all parts of conveyor and all kinds of problems that appeared possibly when the belt conveyor started and brakedAmerica and Australia also have developed dynamic analysis software for belt conveyorIn China，generally， only static properties are considered in the design of belt conveyor system，so it often causes structure arrangement unreasonable，and the parameters of drive assembly，takeup assembly and brake assembly unreasonableAs a result，the local stress of the belt is overlarge or so small that severeaccidents occur，such as the roller bearing is destroyed，the shaft is broken，the conveyor belt is broken or loose，the coal is stacked and the conveyor belt is foldedThe theoretic research on the dynamic properties of belt conveyor is still not mature，but for some more important belt conveyor systems,its expensive to commission CDI (Conveyor Dynamics， Inc)to do dynamic analysis Based on the viscoelastic dynamic equation，the authors made a study on the dynamic displacement and dynamic tension properties of conveyor belt during the acceleration and deceleration of belt conveyor with different takeup assemblyFurther more，reasonable conveyors drive assembly，takeup assembly and brake assembly were designedIt was helpful to limit or eliminate the conveyor belts elastic vibration during the acceleration and deceleration，to prevent the local stress of belt overlarge or too small，to ensure conveyor against danger，and make parameters of conveyor system be optimized and most economical2 Establishing Dynamic Equation of Belt ConveyorBelt conveyor is a transporting system that consists of annular belt，idlers，drive assembly， bend pulleys and takeup assemblySome overseasdesign companies and domestic relative research depal：tments make the belt conveyor discrete in space，that is to say，divide conveyor system into a series of elastic springs and masses，and analyze conveyors dynamic properties with numerical calculation methodIn mathematics，the movement of discrete system uses the ordinary differential equation to describe，and the number of equation is equal to the number of degrees of freedom of the system.To exactly describe and research dynamic characteristic of belt conveyor belt conveyor，in the article，the belt conveyor is regarded as an elastomeric continuous system Assumed that the inertia， elasticity，and damping of elastomeric belt are continuously distributed mechanics model In mathematics the movement of continuous system uses the partial differential equation to describe. Because elastomeric belt can be viewed as inealcutahle particles， continuous system has unlimited degrees of freedom，it can more efficiently simulate belt conveyorBeIt endures the static tension when belt convey runs in the stable state，which mainly includes takeup tension of takeup assembly， gravity of conveyor belt and material，and friction between belt and idlers，and additional resistance and special resistance of conveyor parts.The belt deformation that results from static tension is named static displacement ，and =(x,t)；When belt runs in the unstable state(starting and braking)， belt also endures the dynamic tension that results from change of belt speed，the belt deformation that results from dynamic tension is named dynamic displacement u，and u=u(,t)；Belt sag between idlers sets changes with belt tension，and the belt deformation results from the belts sag change is called geometric displacement v,and v=v(,t).Assuming that the length between two supporting idlers sets is 10，the length between two idlers sets is ，the initial tension between two supporting idlers sets is = (,t)，then both the initial tension and gravity of conveyor belt and material make the belt be a catenaryThe catenarys sag is： whereis the obliquity of conveyor, generally, ， cos1； is the unit length mass of material，(kgm)； is the unit length mass of belt，(kgm)The belt length between two supporting idlers sets is:When belt tension increases from (,t)to S (,t)，the geometric deformation between two supporting idlers sets is：The unit length belts deformation formula is：Assuming that the belt length of belt conveyor is L，m，belt length between the head and the tail of conveyor is ，m；when time is t，the displacement at the position is W，and W= W (，t)=U(，t)+V(，t)Where，U(，t)is the elastic displacement of belt，and U(x，t)= (，t) +u(，t)；V(，t)is the geometric displacement of beltGiven that E is the elastic modulus of belt，(Nmm)：A is the cross section area of belt，mm； is the equivalent viscous damping；q is the total unit length mass of belt，material，and idlers，kgm；a(t) is the acceleration of belt conveyor，msAssumed that dx is a cell，and the distance between the cell and the origin is x，then the elastic displacement of belt at point x is U(x，t)，and solvedThe elastic stress of belt， = E，The viscous stress，=E， The total stress of belt， = +=E(1+)，The beIts tension at the point x，The belts tension at the point(x+dx)，The resistance and the gravity of belt and material on the cell total up to g(x，t)Carrying branch， Returning branch，where， is the friction coefficient between belt and idlers； is the unit length mass of the carrying branch，kgm；is the unit length mass of the returning branch，kgmFor carrying branch，q= +，and for returning branch q= +The drive force on the cells iS：The inertia force on the cells isEquilibrium formula of force on the cell is：Transform formula(2)and solved the viscoelastic dynamic equation of belt conveyor：where，j is the speed of elastic wave，ms，and3 Two Conditions of Belt Conveyor with Constant Automatic Take-Up Assembly31 Boundary conditionsAssuming that there is no slip between drive rollers and conveyor belt， and ignore the deformation of belt on the drive rollersTakeup force of constant automatic takeup assembly is constant，and the displacement(the piston of hydraulic cylinder)of takeup assembly changes with tension of conveyor beltThe boundary conditions of belt conveyor system are as follows：where， indicates the displacement function of time(t)and displacement(y)； indicates the distance from head of belt conveyor to takeup assembly，m 32 Initial conditionsWhen the belt conveyor starts，both initial dynamic displacement and belt speed are zero at point x(OxL)The initial tension of conveyorbelt at takeup assembly is equal to；the takeup tension of take-up assembly The initial conditions are as follows：Initial tensions of conveyor belt at other points are composed of takeup tension of take-up assembly，part gravity of belt and material，and static friction，which is relative to the setting location of takeup assembly and the arrangement of conveyor4 Sol ution to Dynamic Equation of Belt Conveyor and Tension Calculation41 Solution to elastic static displacement and static tension calculationFor the conveyor system adopting prestart，assuming that the elastic displacement of conveyor belt is U(x，t)，and U(x，t)= +u(x，t)， according to the formula(3)and(4)，solved the static displacement of conveyor beltFurther more，the formula(3)can be simplified，So the boundary conditions can be changed，and they are as follows，The initial displacement and speed of belt conveyor are as follows：The static tension of conveyor belt is，42 Solution to elastic dynamic displacement and dynamic tension calculationUsing separation of variables and generalized coordinates，when constant force automatic takeup assembly is adopted，the dynamic displacement of conveyor belt from formula(5)is，where, A（t）=；indicates Vibration frequency of carrying branch of conveyor, ，and =； indicates vibration frequency of carrying branch of conveyor,and indicates damping factor, ，and =； indicates vibration frequency of carrying branch of conveyor when damping is considered，and =The calculation formula of dynamic tension of belt is， The total tension of belt is,4 3 Solution to geometric displ acement of conveyor belt The geometric displacement of equation can be calculated according to the formula(7)，References1费符弗洛林斯基著 ()，杨福新译俄矿井提升钢丝绳动力学M北京：煤炭工业出版社，19572杨复兴编译，蔡学熙校胶带输送机结构、原理与计算(上册)M北京：煤炭工业出版社，19833李玉瑾带式输送机的动态特性分析与软起动设计J北京：煤炭学报，2002，3，27(3)：294299中文翻译：在恒定驱动力作用下带有自动补偿装置的带式输送机的动态张力的研究摘要 本文提供了带式输送机的一种动力学模型.在输送机驱动力的基础上，分析分自动补偿装置的张力，带式输送机和物料的重力以及输送带和托辊间的摩摖力，他给出了带式输送机的粘质弹性动力方程.当自动补偿装置运用于带式输送机时它提供了解决粘质弹性动力方程与几何动力方程的一种计算方法。本文也对限制与消除带式输送机弹性振动的设计方法做出了研究.关键词：带式输送机；动力方程；位移计算；带式输送机张力计算；振动影响限制1. 介绍自从19世纪60年代初期，诸如苏联，德国，澳大利亚，美国，波兰等许多国家，都已致力于对带式输送机动力问题的研究，包括带式输送机零部件和带式输送机启动与制动时所有可能出现的各种问题。美国与澳大利亚也已研制出带式输送机动力分析的软件。在中国，在带式输送机系统的设计中通常只考虑静态特性，因此这种情况经常造成带式输送机结构安排不合理，并且驱动件的参数、自动补偿系统与制动系统不合理。结果带式输送机的局部应力过大或如此的小以致于引发诸如滚动轴承损坏、轴被破坏与带式输送机损坏或松动、煤炭堆积与带式输送机折损的严重事故，对带式输送机动力特性的研究仍不成熟，但对于某些重要的带式输送机系统而言，让输送机动力公司委员会去做带式输送机的动力分析的成本是很高的。依据粘质弹性动力方程，一些作者对带式输送机补偿系统在加速与减速时的动态位移与动态张力特性作了研究。此外，已经设计出结构合理的带式输送机驱动系统、补偿系统与制动系统。这对于限制或消除在带式输送机加速与减速时的弹性振动从而避免带式输送机胶带局部受力过大或过小，确保输送机免受危险工况并使输送机系统的参数达到优化与最经济的效果具有重大帮助。2. 建立带式输送机和动力方程 带式输送机是一个由输送带、托辊、驱动装置、曲度滑轮与自动补偿装置组成的输送系统。一些海外的设计公司与国内的相关研究部门对带式输送机在空间作出了分离，即将带式输送机分解成一些弹性元件与组件并分析带式输送机的动态特性与数据计算方法。在数学计算中，分离系统的运动使用基本的方程描述并且方程个数等于系统自由度的数目。为了更确切的描述与研究带式输送机的动力特性，在本文中，带式输送机被看作是一个弹性的不变系统。假定直线型、弹性并且潮湿的输送带均匀的分布于机构模型中。在数学计算中，不变系统使用稍微不同的方程去描述。由于弹性带可看作是无数个单元组成，不变的系统有无限个自由度，他能更有效的提高带式输送机的效率。当带式输送机在稳定的状况下工作时输送带受到静态张力的作用，这种静态张力主要包括自动补偿系统的张力、带式输送机和物料的重力、带与托辊间的摩擦力与带式输送机部件的特殊张力。由带的静态张力引起的带的变形即静态位移,并且=(,t)；当胶带在不稳定的工况 (启动与制动) 下运行时，带也将承受来自于带速变化而引起的动态张力，带由于动态张力变化而引起的变形被称为动态位移u，并且u=u(,t)；带的张力在托辊装置间变化，并且由于带的伸长而引起的带的变形被称为几何位移v,并且v=v(,t)。 假设两支持托辊装置间的长度为，两托辊装置间的长度为,两支撑托辊装置间的原始张力为= (,t)，原始张力和带与物料的重力引起带的挤压。此挤压引起的下陷量为：式中，是输送机的倾角，通常情况下， ， cos1；为物料单位长度的质量，(kgm)；为胶带单位长度的质量，(kgm)。两支承托辊装置间的带长为： 当带的张力从(,t)减少到S (,t)时，两支撑托辊装置间的几何位移为：带单位长度的变形方程为：假定带式输送机的长度为L，m,输送机头尾间的长度为，m;当时间为t时,在点的位移为W，并且W= W (，t)=U(，t)+V(，t)。式中U(，t)为带的弹性位移，并且U(，t)= (x,t)+ u(,t)；V(，t)为带的几何位移，由于E为带的弹性模量，(Nmm)；A为带的横截面积，mm；相当于粘性摩擦系数；q为带、物料及托辊单