电梯滑动导向系统的摩擦及能耗测量

提出了一套原位测量电梯滑动导靴和导轨间摩擦力及摩擦能耗的装置和方法,并在检修速度下对实际电梯系统进行了摩擦力及其能耗的实验研究。研究表明,实际电梯的各钢丝绳受力不均匀;电梯运行过程中钢丝绳固定端和运动端的受力情况不同;上行的摩擦力和摩擦损耗比下行的摩擦力和摩擦损耗大。     

电梯导靴摩擦特性的实验研究

在电梯系统的设计与制造中,电梯导靴被设计成与导轨紧密接触,并运行在其上.这种导靴与导轨间的表面接触呈现出强非线性滞回摩擦特性,并进而引起电梯轿厢的纵向和横向振动,严重影响电梯运行与乘坐舒适性.在设定的参数条件组合下,实验研究电梯导靴与导轨接触面间的滑动摩擦力及其特性,并呈现出丰富的摩擦特性,如摩擦滞回、预滑动/宏观滑动...     

Ni-Mo-P-Si3N4化学镀层的摩擦磨损性能研究

Q215碳素钢表面上制备一层Ni-Mo-P-Si3N4复合镀层,在MS-T3000摩擦磨损试验机上进行摩擦磨损试验,记录平均摩擦系数,测试磨痕宽度,计算磨损率,研究该化学镀层的摩擦磨损性能。分析结果表明:载荷不变时,平均摩擦系数和磨损率均随滑动速度的增大而增大;滑动速度不变时,平均摩擦系数和磨损率均随载荷的增大而增大;载荷和滑动速度不变时,平均摩擦系数和磨损率随镀层中Si3N4的体积分数先增大后减小。     

层状WC/TiC陶瓷刀具材料与轴承钢的摩擦磨损性能

采用雾化-喷覆液膜-干燥工艺及真空热压烧结技术制备了层状WC/TiC陶瓷刀具材料,在干摩擦条件,将其与GCr15轴承钢进行了摩擦磨损实验,研究了不同滑动速度和不同载荷对其摩擦系数和磨损量的影响规律,并对其摩擦磨损后的表面形貌进行了分析。结果表明:在相同载荷条件下,材料的摩擦系数和磨损量均随滑动速度的升高而减小,当滑动速度为12m/min时,材料的摩擦系数和磨损量最小,其值分别为0.276和0.68×10^-3mm^3;在相同滑动速度条件下,材料的摩擦系数和磨损量也均随载荷的增大而减小,载荷为120N时,材料的摩擦系数和磨损量最小,其值分别为0.157和0.58×10^-3mm^3;材料的磨损机理主要是粘着磨损和磨粒磨损。     

聚氨酯弹性体摩擦衬垫材料的摩擦特性研究

本文研究了聚氨酯弹性体摩擦衬垫材料的摩擦特性,发现聚氨酯弹性体材料的动摩擦系数是和滑动速度有关的,在0．0l-0．4mm／s的速度范围内,速度提高摩擦系数上升,在更高的速度下摩擦系数还会下降。聚氨酯弹性体材料的静摩擦系数是比较难以确定的,本文建议把滑动量较小而滑动速度又很低的这一时期的摩擦称为“初期摩擦”,它是界于静摩擦与动摩擦之间的一种特殊的摩擦状态。文中还分析了粘着摩擦机理,提出了接点化学粘接机理。并根据这种机理对实验结果进行了分析和讨论。     

SiCp增强铝基复合材料与芳纶纤维增强摩擦材料摩擦副摩擦学特性与模型研究

对 Si Cp含量为 2 0 % (vol% )的铝基复合材料和芳纶纤维增强摩擦材料组成的摩擦副在干摩擦条件下的摩擦学特性进行了试验研究。试验表明 :摩擦副的摩擦系数受 Kevlar增强摩擦材料的热分解温度所控制 ,当温度低于2 0 0℃时 ,摩擦系数随滑动速度和温度增大而增大 ,并处于较高水平 ;当温度高于 2 0 0℃时 ,摩擦材料发生热分解 ,摩擦系数急剧下降到较低水平。摩擦材料具有磨损量和磨损率随滑动速度增加而减小的明显特征 ,摩擦副具有良好的耐磨性。建立了描述该摩擦副摩擦特性的数学模型。并用其解释了实验中的摩擦学现象。     

摩擦带弹性滑动率与摩擦损失效率计算及实验

摩擦带传动应用广泛,但由于弹性滑动的存在,传动效率并不理想。基于弹性体欧拉公式推导出含带离心力影响的弹性滑动率表达式,得出影响弹性滑动的因素为初拉力、小带轮动角、摩擦系数及皮带的弹性模量、横截面积;采用积分原理得到带与带轮摩擦损失总功率的计算式,指出采用弹性模量较大值材料的皮带及控制带速可降低摩擦损失功率;推导了摩擦损失效率关于弹性滑动率的关系式,并通过PC-B型皮带传动实验台实验验证。研究结果表明:弹性滑动是导致效率损失的主要因素;摩擦损失效率与弹性滑动率成非线性正相关。上述研究为带传动理论研究和工程应用奠定了基础。     

摩擦条件对磁轨制动器极靴材料与钢轨材料间摩擦因数的影响

将磁轨制动器极靴用铸造Q235B钢和油淬硬化45钢组成销-盘摩擦副进行摩擦试验,研究了滑动速度(10～100 km·h-1)、法向载荷(10～80 N)和润滑条件(干摩擦、水润滑)对摩擦因数和磨损机制的影响.结果表明:随着滑动速度的增大,摩擦副的摩擦因数均在3s内达到稳定;稳定摩擦因数随滑动速度的增大先增大后减小,但变...     

滑动速度对油润滑表面胶合磨损的影响

在油润滑条件下,钢对钢摩擦副的胶合摩损不仅取决于润滑油膜是否破裂,而且取决于在摩擦表面上化学反应膜的形成情况。本文研究了在油润滑条件下滑动速度对钢摩擦副胶合的影响。在低滑动速度下摩擦表面易于形成反应膜,油膜破裂后并不直接发生胶合。胶合发生在高温、高摩擦系数的恶劣条件下。在高滑动速度下油膜破裂后很容易发生胶合,发生胶合前的表面温度和摩擦系数都比较低。     

湿式离合器考虑纸基衬面孔隙弹性特性摩擦振动理论

本文提出考虑纸基摩擦材料界面间变形和其中造成润滑油流动的摩擦振动新理论,推荐了一摩擦振动模型,采用引入的粘性液体浸透多孔体,联合假定在切向和法向两个方向的振动导出一稳态准则,和实验相比较,确认所推荐的准则可预测该稳态极限比常规的更精确。它不考虑摩擦材料的变形,只与摩擦系数与滑动速度的斜率有关。基于本准则,讨论了材料特性摩擦振动对稳态的影响。     

A Model for Magnetic Tape/Guide Friction Reduction by Laser Surface Texturing

The friction coefficient between a magnetic tape and a guide in a tape path can be minimized by creating micro dimples on the guide surface with laser surface texturing. The dimples enhance the formation of an air bearing and reduce the friction coefficient between the tape and the guide due to the increased spacing. A model is presented to optimize the geometry of the surface texturing parameters to maximize the average air bearing pressure and minimize the tape/guide friction coefficient.     

电梯导靴引起的振动

本文对电梯运行时导靴的非线性摩擦影响进行了数学模型分析，提出了抑制自激振动的各种措施，同时将结果推广于自动扶梯扶手带的蠕动运行和对电梯平层的影响，文中对导靴引起的瞬态振动也进行了适当的说明。     

Correlation between solid particle erosion of cermets and particle impact dynamics

Since the erosion rate depends on energy exchange between particle and material, a reformulation and solution of the equations of two solid bodies collision is presented and adapted to the calculation of the energy absorbed by a material surface during impact of a spherical particle onto a plain target. It has been observed that energy loss is a strong function of dynamic coefficients named as coefficient of velocity restitution after impact, k, and coefficient of dynamic friction, f. The new method and experimental equipment for the coefficients determination are described. It was shown that energy consumption during application may be an appropriate guide for the material selection in the conditions of erosive wear.     

摩托车盘形制动器摩擦片材料磨损形貌分析

采用XDZ-A型摩擦材料制样机将有机石棉摩擦片材料制备成试验所需的标准试样,用X-DM型调压变速摩擦试验机模拟摩托车制动实际工况,对标准试样开展不同压力、滑动速度和温度下的组合试验.对扫描电子显微镜(SEM)观测到的有机石棉摩擦片材料与灰铸铁HT250摩擦盘对磨后的磨损形貌进行了分析.分析结果表明:无论是正压力、速度的增大还是温度的升高,都使得摩擦片磨损越来越严重,形貌越来越复杂.     

An Adsorption Model for Friction in Boundary Lubrication

A model describing the relationship between friction coefficient and surface adsorption of a two-component lubricant (i.e. base lubricant and one additive) is developed for boundary lubrication. This model relates the coefficient of friction to the extent of metal-metal contact or, inversely, the fractional surface coverage of the lubricant. Using a suitable adsorption isotherm, an expression for friction coefficient is obtained, relating the friction coefficient to the additive concentration and the adsorption energy. The proposed model and the selected adsorption isotherm are experimentally verified by testing several model additives in a petroleum-base lubricant. An excellent correlation is obtained between the adsorption-free energies calculated from the friction coefficient data and the adsorption-free energies determined from adsorption studies. The ranking order of additives based on friction coefficient is explained in terms of the molecular structure and the structural effects on the adsorption-free energy.     

Recent research of tape/drive tribology

Decreasing track width and tape thickness to increase the volumetric recording density of helical scan-tape-drive systems, which is suitable for higher volumetric recording density, will result in the failure of tracking. The displacement of tape forwarding position, which causes failure of tracking, is caused by static friction coefficient between a tape and a roller guide. It was found that surface roughness and materials of roller guides are very important to reduce static friction coefficient.     

指定摩擦系数下富锌漆漆膜厚度的计算研究

对富锌漆接触面间的摩擦系数进行了测量,结果表明：不同处理方式的富锌漆接触面间的摩擦系数差异较大,并且摩擦系数与接触面积成正比。对某2 MW风机主轴与轮毂栓接面间异响的研究表明：喷砂后球型无机富锌漆接触面间的摩擦系数有时可接近于0。通过推导栓接面间的摩擦系数与粗糙度的数学解析表达式,结合球型无机富锌漆膜厚度与粗糙度在一定条件下近似相等的特性,找到了一种指定摩擦系数下富锌漆漆膜厚度的计算方法,保证了栓接面间在喷涂富锌漆后其摩擦系数的可靠性和可计算性。通过测量某塑性材料的摩擦系数,得到了一种简洁的估算该塑性材料的临界应力强度因子的方法。     

纳米碳酸钙与液晶添加剂的摩擦磨损分析

在15^#机械油中添加纳米碳酸钙或纳米液晶,用标准的立式万能摩擦磨损实验台实验分析了15^#机械油、15^#机械油＋纳米碳酸钙、15^#机械油＋5CB液晶的摩擦磨损性能。针对磨合阶段、稳定磨损阶段、胶合失效与摩擦噪声进行分析。结果表明,在磨合阶段摩擦因数有较大变化,随后的稳定磨损阶段中摩擦因数变化减小,在摩擦副出现胶合失效前,摩擦副的摩擦因数急剧上升;在摩擦因数变化幅度达到5％左右时出现嗡嗡声,在摩擦因数变化幅度达到10％左右时,在摩擦因数上升阶段出现摩擦啸叫声,而在摩擦因数下降阶段不出现摩擦噪声。提出了用能量耗散原理来解释上述现象。     

一种新型洗鞋机的设计

提出了一种全新的洗涤鞋子方法,利用混有洗涤液和固体颗粒物的有一定压力的和流速的水流,冲击鞋面和鞋子内部,在水流和固体颗粒物的冲击、摩擦作用下,鞋子表面附着的污垢被清除,并以此方法为基础,提出了新型洗鞋机器的设计思想。     

Friction and Wear Behavior of Steels under Different Reciprocating Sliding Conditions

The friction and wear behavior of ISO 100Cr6 steel ball sliding against conventionally hardened carbon and low-alloy steels was studied. The effect of hardness, hardening capacity, normal load, and sliding speed on the coefficient of friction and friction energy was investigated. Friction tests were carried out, without lubrication and under ambient conditions, on a reciprocating friction tester in which a ball-on-flat contact configuration was adopted. The results showed that there is a relative tendency for the friction properties to decrease with increased hardening capacity and decreased hardness. The results showed that increasing normal load decreases the coefficient of friction for the two steel nuances. However, increasing sliding speed increases the coefficient of friction of low-alloy steel and decreases the coefficient of friction of carbon steel. The oxidation of wear debris influences the wear mechanisms and friction behavior.