机械设计外文翻译-矿井提升机和数值的摩擦热分析模拟垫片的温度场【中文4130字】【PDF+中文WORD】
机械设计外文翻译-矿井提升机和数值的摩擦热分析模拟垫片的温度场【中文4130字】【PDF+中文WORD】,中文4130字,PDF+中文WORD,机械设计,外文,翻译,矿井,提升,数值,摩擦,分析,模拟,垫片,温度场,中文,4130,PDF,WORD
【中文4130字】
矿井提升机和数值的摩擦热分析模拟垫片的温度场
机电工程，矿业，江苏徐州221008，中国的中国大学学院
摘要:密封垫圈的摩擦性能影响矿井提升机，摩擦热基于摩擦机制和传热理论，矿山的数学模型对聚氯乙烯垫片的温度场进行了研究，根据基本假设，利用ANSYS数值模拟给出温度和热通量的分布，该结果表明，温度逐渐减小，模型半径增加而等温线是同心半圆的圆弧，热通量是双侧对称的模型并且径向减小。当钢丝绳滑动时，该理论值与很短的时间测量值相对应（t<=100次）。
关键词: 矿井提升机；摩擦热；垫片；数值模拟；温度场
1 引言
矿用提升机的垫片主要由PVC塑料和PU制成，其有聚合物性能。热导率PVC塑料和PU相对较小，该材料温度因而上升，由于摩擦热而引起的滑动，将导致相位状态的改变与结构的变化。以前实验证明，影响摩擦热的最重要因素之一是垫圈。在很大程度上是由指示的摩擦系数，从而降低与一个在折合在聚合物密封垫圈的温度[1]。聚合物对热敏感，这可以改变摩擦表面状况，加剧磨损，结果脱矿或脱落表面层[2]。因此，在研究摩擦时应考虑钢丝绳之间的机制垫片的摩擦热，主要步骤是在垫片摩擦时了解温度场的变化，以便获得影响摩擦的各种因素。
2 滑动摩擦热的机构
2.1 滑动模式
一般情况下，矿井提升机在操作时，绝对和相对滑动因为某些原因而存在作用[3]。绝对（纯滑动）采用下进行两种情况：第一种是，该钢丝绳在摩擦轮转动时，就在该点如不能解除重量，同时提升；另一种是，该钢丝绳上滑动的摩擦垫圈，类似于在紧急制动电的情况。相对滑动是在摩擦副工作时引起的差值，绝对速度通常也发生两种情况：在第一个是该钢丝绳的速度比该摩擦轮的大，这相当于为滑动卸载它的重量和减慢，另一条件是速度小于钢丝绳，这相当于滑动时升降在过载运行。
2.2 钢丝绳和垫片摩擦热产生机理
摩擦热摩擦过程中的主要作用为滑动，热量从摩擦工作产生，这直接关系到了摩擦力和滑动速度。欧拉公式是摩擦提升机的主要驱动原理[4]。
1.它可写为：
（1）
钢丝绳的拉伸力的限制比例在摩擦轮的两侧，如图所示：
图1 钢丝绳两侧拉力
(1) 其中e是自然对数2.71828，α0封闭钢丝绳相对于所述摩擦轮的角度来看，μ钢丝绳和垫圈和T1和T2之间的摩擦系数是在重量的拉伸力。拉伸力和正常压力之间的关系是
Ni = Tdθ （2）
(2) 其中Ni是正常的气压，T为拉伸力和dθ对应的接触弧度为单位的微角。在滑动时，总摩擦力（T1- T2），并且如果滑动速度υ，总摩擦实际功（Wf）是许多小曲线的总和摩擦功（Wi）[5]：
（3）
(3) 滑动中垫圈的接触面始终加热，一般情况下，如果两个对象纹理和几何形状彼此相似，摩擦热通常是良好的显示分布式[6]，否则，更多的热量会传导至对象具有良好的导电性。在滑动钢丝绳和垫圈，钢丝之间绳子将获得更多的热量，但只有垫片的5％的摩擦热主要是产生于分离表面，该表面容易磨损，因此它不利地影响衬垫。为了充分理解摩擦热效应，摩擦产生热应该考虑对整个接触面积。
钢丝绳和之间的导通的垫片是不稳定的，摩擦热的条件，滑动过程中的钢丝绳示于图2(1)，这是相当复杂的，因为该半圈是加热，而其它部分释放热量。在接触的横截面的传热条件，钢丝绳与衬垫之间的区域显示图2(2)，这表明了热q是良好的显示分布式上的联系方式与圆弧半径为r0，外加面对热源会在接触区域中创建在整个摩擦轮的滑动，以热钢丝绳和垫圈加热表面的接触面积。根据摩擦角变化，热源强度增加在滑动方向上，如图2（3）和所述热在入口Q''始终是较大的比热在出口Q'[1-2]。在研究中，垫圈通常被采用为目标，作为一个结果的复杂性和该结构的均质性钢丝绳，它是更方便的考虑垫片为连续均质材料[7]。
(1) 垫片 (2) 摩擦热条件
图2 钢丝绳和衬垫滑动时的摩擦热条件
3 温度分布模型
3.1 基本假设
考虑到热是不可改变的，它只有在封闭时钢丝绳和衬垫的某些接触面积角度改变，作为滑动条件是不变的，下面假设：
1)我们忽略了滑动时垫片的磨损，钢丝绳的接触形式在一定的工作条件不变。该整个表面是一个大圆弧半径R和当地接触面积是半径为r0的圆弧（钢丝绳半径）；
2)垫片各向同性聚合物具有恒定的热传导性，是一种均匀连续的热扩散率，比热容和密度；
3)非接触表面，其被暴露在空气中，是隔热的，也就是说，它不会传递热量到空气；
4)在接触弧的任何横截面的热是恒定的，均匀分布的小接触圆弧半径为r0；
5)热传递的方向进行半径r和等温线是同心的，半圆中心是钢丝的轴线。
3.2 控制方程
基于以上假设，我们得到如图所示，如图物理模型。该模型具有三面与周围环境接触，钢丝绳与垫圈的接触面这是直接由摩擦加热，其中所述热量Q是均匀分布，垫圈接触面和其周围的空气，在其上的热量有上一层极薄的效果，因此温度变化小，热对流的空气可以忽略不计；垫片接触面和接触区域的沉积，对于基于同样的理由，热可以忽略。该坐标的三维模型的系统是与坐标R，θ和φ确定。Ř是垫圈和一个绳芯横截面的距离是特定之间的，θ为该角度从点到对称平面和φ是垫圈和其水平位置之间的横截面为逆时针角。
图3 垫片的物理模型
摩擦热的扩散是不稳定的，因而我们有数学传热模型[5]如下：
（4）
其中，λ是热传导率，T温度，τ时间，R绞盘轴之间的距离钢丝绳芯，这是常数，表示热扩散。该边界条件和初始条件是:
（5）
方程（4）是一局部方程，由于传热在密封垫被认为是一个整体。方程（4）是通过分析或数值非常复杂技术，并在实践中加以简化。该摩擦热表面层是很薄的，因此热影响小；并且进一步地和之间的同一个差别系数较小时，是非常小的，和之间的影响是小的，只要它们之间存在一定的距离。因此，值被认为是一个常数和热传导可以转化为一种不稳定的热传导，一维中空圆柱体的内壁具有同等热。简化的物理模型被示为图4，并在任何数学模型角被计算如下：
图4 垫片的简化物理模型
(6)
其中在任何时间，t是在半径r处的温度，是单位长度上电弧的接触面的热流量。
4 在温度场的数值模拟
4.1 有限元分析
垫片的传热分析通过有限元软件分析，温度模拟其特殊多场耦合功能。传热分析过程中使用分析如下：首先，划分对象，以有限的单位（内包括一些结点）[8] ；第二，根据给定的平衡解决散热，每个结点的方程边界条件和初始条件根据能量守恒原理；第三，制定出温度在每一个点和最后解决其他相关变量[9]。简化的模型是一个三维中与内壁等于热通量的非稳定热传导问题，因此只有一个横截面需要分析。在这的横截面，所述内半径等于所述钢丝绳半径，即R0= 1.9毫米，其厚度为2.1毫米，横截面为半环形，其横截面面积和网格分布示于图5。有半径20等分和在外围80等分。
图5 物理模型尺寸和网格分布
4.2 垫片的属性和初始边界条件
1) 材料特性：PVC塑料与密度（ρ）1390千克/平方米，比热（Cp）1842.2焦耳/（千克·℃），热导率（λ）0.145（W/（平方米·℃）;
2) 大小和动态参数：内径为1.9毫米，外半径为4毫米，T2=217.56 N和V=69.33毫米/秒;
3) 边界条件：AB，BC和CD边隔热有相等的热通量;初始条件：T=0，T0 =20℃，R= 4毫米，Q =0 R=1.9毫米，q = q0。
我们采取钢丝的外壳角绳索和摩擦轮作为和摩擦力
图6 温度和热通量在一定时间分布
温度和热流量的变化过程在某个时间点被显示在图7，在不同的距离选择沿着从靠近半径的点。前40秒钟该曲线在小的径向点是大，这表明当温度上升并相对于所述垫圈3钢丝绳的系数为0.35，在假定的摩擦力的5％热传导到垫片和热通量垫片是每单位长度的圆的摩擦热。其计算公式可以推导出公式（1）和（3）
因为双方的热通量为零，则该计算值可以直接加入到在横截面扩大的每个结点[10]。
4.3 结果与分析
结果如温度场，热通量场，热梯度场可以在绘图上显示，这可以使各物理量的变化与时间或空间更直观[11]。
温度和热通量的分布在一定时间清楚地显示在图6，这表明温度逐渐降低在半径折痕，等温线是同心圆弧半圈，热通量具有对称分布和径向减小。
热通量梯度大，所以热传导是在不正常的阶段。过一会儿的斜坡曲线接近一个固定的值，这意味着热通量在这些点是恒定的，温度升高和每个点的热通量梯度成为浓度恒定，从而使热传导是在一个稳定的阶段。
图7 变化的温度和热流量的过程在一个特定的时间点
图7a为线1，2，3，4比理论值，而线1’，2’，3’，4’代表测试温度）。
从图中可以看出图7b，该热流的折痕半径逐渐日益增加，这是节能减排的结果。作为在热流的边界的模型内进行，其中的一部分传输到单元的热被用于能源变化的单元；换句话说，它提供了能量使温度上升，而其他部分出口到其他单位，这些结果表明垫圈的瞬态温度场可准确地模拟，由计算机和数字仿真可以反映但不能在实践中测量(例如垫圈的内侧)部分温度场的变化趋势。
5 测试
该实验进行了验证结果的模拟，该实验装置的设计以同样的方式作为真正的悬挂状态。钢丝绳上滑动实验轮是一个卷轴由直流电动机驱动旋转，滑动速度是由直流电动机的电压控制，通过一个变压器和应力对垫片调节是由不同的配重调整。该条件的绝对滑动化可以实现，同时实验绞盘是固定的，条件相对滑动也可以实现。同时，不同速度由两个直流电机驱动阀芯和绞盘，绝对滑动或相对速度滑动可以由测速发电机进行测量和光电传感器的拉伸力，在进口和测试部分的出口通过拉伸来测量力传感器和温度通过以下方式测定淹没热电偶温度计。已被证明，钢丝绳滑动在很短的时间，理论值和测量值基本上匹配，因此，在滑动的开始，热量从垫片被转到接触面积和温度的分布在所述垫圈可以用数值计算仿真。滑动的后期可以理解积累的热量已经影响了垫片表面，并导致其热的放大电导率[12]，这说明不符合同情形测得的温度与理论之间在后期的价值。
6结论
建立钢丝绳和垫圈之间的热传递模型，这可用于不同的密封垫。模拟后期的温度场重量和速度，气温逐渐取消折痕，模型半径增加，而模型中的等温线的同心半圆弧线热焊剂具有对称分布并径向减小，钢丝绳滑动时理论值吻合。
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Received 12 May 2008;accepted 15 August 2008 Projects 50225519 supported by the National Outstanding Youth Science Foundation of China and 0E4458 by the Youth Science Foundation of China Univer-sity of Mining and Technology Corresponding author.Tel:+86-15852498680;E-mail address: Frictional heat analysis of mine hoist and numerical simulation on temperature field of gasket HAN Dong-tai,GE Shi-rong,DU Xue-ping School of Mechanical and Electrical Engineering,China University of Mining&Technology,Xuzhou,Jiangsu 221008,China Abstract:The frictional performance of gaskets is greatly affected by frictional heat in operational mine hoists.Based on frictional mechanism and heat transfer theory,the mathematical model of the temperature field of the PVC gasket in an operational mine hoist was investigated,a numerical simulation using ANSYS is presented and the distribution of the temperature and heat flux were studied under basic assumptions.The results show that the temperature gradually decreases as the radius of the model increases and the isotherms are arcs of concentric semi-circle.The heat flux is of bilateral symmetry in the model and decreases radially.The theoretical values correspond with the measured values for a short time(?100 s)when the steel wire rope slides.Keywords:mine hoist;frictional heat;gasket;numerical simulation;temperature field 1 Introduction These days,gaskets of mine hoists are mainly made of PVC plastic and PU polyurethane which have polymer properties.The thermal conductivity of PVC plastic and PU polyurethane is relatively small,thus the rise of the temperature of the material,caused by frictional heat while sliding,will lead to a change in the phase state and in structure.Previous experiments proved that frictional heat is one of the most important factors affecting the frictional per-formance of the gasket.This is largely indicated by the friction coefficient,which decreases with an in-crease in temperature of the polymer gasket1.Poly-mers are sensitive to heat,which can change the fric-tional condition of its surface,aggravates abrasion and results in the demineralization or abscission of the surface layer2.Therefore,frictional heat and its effects should be considered in investigating the fric-tional mechanism between the steel rope and the gasket.The primary step is to know about the distri-bution and variation of the temperature field of the gasket during the friction process,in order to obtain an insight of the various factors affecting frictional heat.2 Mechanism of sliding frictional heat 2.1 Sliding modes In general,both absolute and relative slides exist for certain reasons while the mine hoist is in opera-tion3.The absolute slide(pure slide)takes place under two conditions:the first one is that the steel wire rope rests as the friction wheel is rotating,just at the point where it cannot lift the weight while hoisting;the other is that the steel wire rope slides on the frictional gasket,similar to that in the case of emergency brak-ing.The relative slide is caused by the difference of the absolute velocities of the friction pairs while working and usually also takes place under two conditions:the first one is that the speed of the steel wire rope is lar-ger than that of the friction wheel,which is equivalent to the sliding as the hoist unloads its weight and slows down;the other condition is that the speed of the fiction wheel is larger than that of the steel wire rope,which is equivalent to sliding when the hoistoperates under overload.2.2 Mechanism of frictional heat generation be-tween steel wire rope and gasket Frictional heat is the main effect of friction during sliding.The heat is generated from the frictional work which directly relates to the friction force and sliding speed.The Euler formula for soft wire drive is the main driving principle of the friction hoist4.The limit ratio of the stretch forces of the steel wire rope on the two sides of the friction wheel,as seen in Fig.1.It can be written as:Mining Science and Technology 19(2009)00400044MININGSCIENCE AND TECHNOLOGY HAN Dong-tai et al Frictional heat analysis of mine hoist and numerical simulation 41Fig.1 Stretch forces of steel wire rope on both sides of the fiction wheel in its penultimate state 012/eT T=(1)where e is the natural logarithm to the base 2.71828,0 the enclosed angle of the steel wire rope with respect to the friction wheel,the frictional coeffi-cient between steel wire rope and gasket and T1 and T2are the stretch forces on the weight and light side,respectively.The relationship between the stretch force and normal pressure is diNT=(2)where iN is normal pressure,T the stretch force and d the micro-angle corresponding to a unit of con-tact radian.During the sliding,the total frictional force is(T1T2)and if the slide speed is,the total fric-tional work(Wf)is the sum of many mini-curve fric-tional works(Wi)per unit of time5:()f12iWWTT=?(3)The contact surface of the gasket is always heated by frictional heat during the absolute slide.Generally,if the two objects are similar to each other in texture and geometry,the frictional heat is usually well-dis-tributed6;otherwise,more heat will conducted to the object with good conductivity.During the sliding between the steel wire rope and gasket,the steel wire rope will gain more heat,but the gasket gains only 5%.The frictional heat is generated largely on the segregated surface which is easily abraded,so it badly affects the gasket.In order to understand fully the frictional heat effect,the generation of frictional heat should be considered on the entire contact area.The conduction between the steel wire rope and the gasket is unstable.The frictional heat conditions of the steel wire rope during sliding are shown in Fig.2(1).It is rather complex because the semi-circle is heated and the other parts release heat.The heat transfer condition at a cross section of the contact area between the steel wire rope and gasket is shown in Fig.2(2),which shows that the heat q is well-dis-tributed on the contact arc with radius 0r.The sur-face heat source will be created on the contact area during the sliding of the entire friction wheel to heat the steel wire rope and gasket.The heating surface is the contact area.According to the variation of the friction angle,the intensity of the heat source gradu-ally increases in the sliding direction,as shown in Fig.2(3)and the heat at the inlet q is always larger than the heat at the outlet q12.In research,the gasket is usually adopted as the target as a result of the complexity and heterogeneity of the structure of the steel wire rope.It is more convenient to consider the gasket as continuous homogeneous material7.Fig.2 Frictional heat conditions of steel wire rope and gasket during sliding 3 Temperature distribution model of gas-ket 3.1 Basic assumptions Considering that the heat is unchangeable on a certain contact area of the steel wire rope and gasket and that it only changes with the enclosed angle 0as the sliding condition is unchanged,the following assumptions are made:1)We ignore the abrasion of the gasket in the slid-ing process;the contact form of the steel wire rope is unchangeable under certain working conditions.The entire form is a large arc with radius R and the local contact area is an arc with radius 0r(the radius of the steel wire rope);2)The gasket is a homogeneous,continuously iso-tropic polymer with a constant heat conductivity,thermal diffusivity,heat capacity and density;3)The non-contact surface,which is exposed in air,is heat insulation,i.e.,it will not transfer heat to the air;4)The heat?at any cross-section of the contact arc is constant and well-distributed on the small contact arc with radius 0r;5)The heat transfer is conducted in the direction of radius r and the isotherms are pieces of the concentric semi-circle whose centre is the axes of the steel wire rope.3.2 Governing equation Based on the assumptions above,we obtained the physical model as shown as Fig.3.The model has three surfaces in contact with the surroundings:I is the contact surface of the steel wire rope and gasket which is heated directly by friction,where the heat qis well-distributed;is the contact surface of?the gasket and its surrounding air,on which the heat has effect on an extremely thin layer,thus the tempera-Mining Science and Technology Vol.19 No.142ture changes little and the heat convection with the air can be ignored1;is the contact surface of the?gasket and the deposit of the contact area.For the same reasons,the heat transfer can be ignored.The coordinate system of the three-dimensional model is established with the coordinates r,and.ris the distance between a certain point in the cross-section of the gasket and the rope core,is the angle from the point to the symmetric plane and is the counter-clockwise angle between the cross-section of the gasket and its horizontal position.()q is the heat at angle.Fig.3 Physical model of gasket The diffusion of the frictional heat is unstable,thus we have the mathematical heat transfer model5 as follows:()()()()222222222 cos11cossin1 coscosRrttttarr Rrrrttr RrRr=+(4)whereis the heat conductivity,t temperature,time,R the distance between the capstan axes and the steel wire rope core,which is constant;()/pac=,denoting thermal diffusion.The boundary conditions and initial conditions are()()00?0,0202?00 ,ltttrrrqrt rt?=?=?=?=?(5)Eq.(4)is a partial equation,since the heat transfer in the gasket is considered as a whole.The solution of Eq.(4)is very complex by analytical or numerical technique and has to be simplified in practice.Thesurface layer affected by the frictional heat is very thin,thus the heat effect is small;and further,the dif-ference between()q and()q+is small when is very small,and the effect between()q and()q+is small as long as there is a certain distance between them.Therefore,()q can be considered as a constant and the heat conduction can be transformed to an unstable heat conduction of a one dimensional hollow cylinder with equal heat flux on the inner wall.The simplified physical model is shown as Fig.4 and the mathematical model at any angle is obtained as follows:Fig.4 Simplified physical model of gasket()20211o0=?rltttttaat ttr rrqrrrrrrrr?=+=?=?=?(6)where t is the temperature at radius r at any time in the gasket;()lq is the heat flow rate of unit arc length on the contact surface.4 Numerical simulation of the tempera-ture field 4.1 Finite element analysis The heat transfer analysis of the gasket is investi-gated by the FEM software ANSYS,which is advan-tageous in temperature simulation for its special multi-field coupling function.The heat transfer analysis process using ANSYS is as follows:first,divide the object to finite units(in-cluding some nodal points)8;second,solve the heat balance equation of each nodal point under the given boundary and initial conditions,according to the en-ergy conservation principle;third,work out the tem-perature at each point and finally,solve for the other relative variables9.The simplified model is an un-stable heat conduction problem of a 3D hollow cyl-inder with equal heat flux on the inner wall;therefore just one cross-section needs to be analyzed.At this cross-section,the inner radius is equal to the steel wire rope radius,that is,r0=1.9 mm,its thickness 2.1 mm and the cross-section is a half annulus whose cross-section area and grid distribution are shown in Fig.5.There are 20 equal divisions in the radius and 80 equal divisions in the periphery.The grid distribu-tions are given by the ANSYS menu:Mesh-Areas.HAN Dong-tai et al Frictional heat analysis of mine hoist and numerical simulation 43?Fig.5 Physical model size and grid distribution 4.2 Gasket properties and initial boundary con-ditions 1)Material properties:PVC plastic with den-sity()1390 kg/m3,specific heat()pc 1842.2 J/(kgC)and heat conductivity()0.145(W/(mC);2)Size and dynamic parameters:inner radius is 1.9mm,external radius is 4 mm,T2=217.56 N and=69.33 mm/s?3)Boundary conditions:the ab,bc and cd sides are thermally insulated,the ad side is of equal heat flux;initial conditions:?=0,t0=20 C;r=4 mm,q=0;r=1.9 mm,q=0q.We have taken the enclosure angle of the steel wire rope and the friction wheel as?,and the frictional coefficient of steel wire rope relative to the gasket?as 0.35,on the assumption that 5%of the frictional heat is conducted to the gasket and the heat flux on the gasket is the frictional heat per unit circle length.The calculation formula can be deduced from Eqs.(1)and(3)00200.05(e)/?qTTr=?(6)Because the heat flux of the three thermally insu-lated sides is zero,the calculated value 0q can be directly added to each nodal point in the cross sec-tion10.4.3 Results and analysis The results such as the temperature field,heat flux field,heat gradient field can be shown in a drawing which can make the change of each physical quantity with time or space more intuitive11.The distributions of temperature and heat flux at a certain time are clearly shown in Fig.6.It shows that the temperature gradually decreases as the radius in-creases,the isotherms are arcs of concentric semi-circles,and the heat flux has a symmetric distribution and decreases radially.(a)Isotherms (b)In X direction (c)In Y direction Fig.6 Distributions of temperature and heat flux at a certain time The changing process of temperature and heat flow at a certain point in time is shown in Fig.7.Four points were chosen along the radius from near to far at different distances.The slopes of the curves at the small radial points are large at the preceding 40 sec-onds,which indicates that the temperature rise and heat flux gradient are large,so the heat conduction is at an abnormal stage.After a while,the slopes of the curves approach a fixed value which means the heat flux at these points is constant,the rise in temperature and the heat flux gradient of each point become con-stant,so that the heat conduction is at a steady stage.?(a)Temperature (b)Heat flow Fig.7 Changing process of temperature and heat flow at a certain point in time Mining Science and Technology Vol.19 No.144It can be seen from Fig.7b that the heat flow de-creases gradually with the increasing radius,which is the result of energy conservation.As the heat flow on the boundary is conducted inside the model,one part of the heat transferred into the unit is used for energy change of the unit;in other words,it provides the energy for the increase in temperature;the other part is exported to other units.These results indicate that the transient temperature field of the gasket can be accurately simulated by computer and the numerical simulation can reflect the changing trend of the tem-perature field of the part that cannot be measured eas-ily in practice(such as the inside of the gasket).5 Tests The experiment was carried out to verify the result of simulation.The experimental set-up is designed the same way as the real hoisting condition.The steel wire rope slides on the experimental wheel which is rotated by a reel driven by a DC motor.The sliding speed is controlled by the voltage of the DC motor,adjusted by a transformer and the stress on the gasket is adjusted by different balance weights.The condi-tion of absolute sliding can be achieved while the experimental capstan is fixed and the condition of relative sliding can be achieved while the speeds of the spool and capstan driven by two DC motors are different.The speed of absolute sliding or relative sliding can be measured by a tachogenerator and photoelectric sensor;the tensile forces at the inlet and outlet of the test part can be measured by a tensile force sensor and the temperature can be measured by the submerged thermocouple thermometer.It has been proved that the theoretical value and the measured value are basically matched over a short time(?100 s)as the steel wire rope slides(shown in Fig.7a as lines 1,2,3,4 representing theoretical values,while lines 1?,2?,3?,4?represent the test tem-peratures).Therefore,the heat transferred from the contact area to the gasket and the distribution of tem-perature in the gasket can be calculated by numerical simulation at the beginning of sliding.The error in the late period of sliding can be understood as the accumulation of heat on the surface that has affected the gasket and resulted in the enlargement of its heat conductivity12.This indicates the lack of conformity between the measured temperature and the theoretical value in the late period.6 Conclusions The model of heat transfer between steel wire rope and gasket is established,which can be used to simu-late the temperature field of gasket under different weights and speeds.The temperature gradually de-creases as the radius of the model increases and the isotherms are arcs of concentric semi-circles;the heat flux has a symmetrical distribution in the model and decreases radially;the theoretical values agree quite well with the measured values over a short time(?100 s)as the steel wire rope slides.Acknowledgements Financial support for this work,provided by the National Outstanding Youth Science Foundation of China(No.50225519)and the Youth Science Founda-tion of China University of Mining and Technology(No.0E4458),is gratefully acknowledged.References 1 Liu D P.Studies on Friction Heat Partition for Friction Hoist Master dissertation.Xuzhou:China University of Mining and Technology,1989.(In Chinese)2 Xiao G R,Wang Z G.Superficial view on friction heat effect.Journal of Sichuan University of Science and Technology,1995,14(3):7477.(In Chinese)3 Liu D P.Some problems of frictional heat effects.Lubrication Engineering,1994,15(6):614.(In Chinese)4 Yang Z J.Studies on Tribology Characteristics of Gasket Material of Multiple-cable Friction Hoist Master dis-sertation.Xuzhou:China University of Mining and Technology,1987.(In Chinese)5 Yang S M,Tao W Q.Heat 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