基于摩擦的高层建筑缓降逃生装置的创新设计

提出了两种基于摩擦的纯机械高楼自助缓降逃生装置,该装置不需要外在动力,可多人次循环使用;其基本原理是利用偏心钟摆／杠杆增力结构使逃生者自重转化为相应的摩擦阻力。逃生者体重越重,该装置产生的摩擦阻尼越大,从而使不同体重的人都能以近似相同的安全速度缓降逃生。该装置结构紧凑、简单,并通过机械结构和力学方面的分析计算和高楼缓降试验,证明其安全可靠。     

摩擦片式高楼缓降逃生器

提出了一种基于摩擦片的纯机械高楼缓降逃生器.该逃生器不需要外在动力,简单、实用、可靠,下降速度稳定,且造价较低.本高楼逃生器使用凸轮齿造成摩擦力来控制缆绳轮转动速度,以此作为逃生器缓降的阻尼系统主要结构,帮助逃生人员从高处平稳下降、安全地到达地面.     

基于摆线针轮减速作用的新型缓降设备研发

针对高楼应急逃生,设计了一种由减速机构和阻尼机构等组成的新型高楼缓降设备,采用ANSYS软件对其关键部位进行强度分析,并在实验中获得了缓降装置在不同负载下的运动规律。结果表明,该设备能适应不同重量的人群平稳下降,对缓降设备的研发具有参考价值。     

高空逃生机械限速下降机的创新设计

阐述了一种高空逃生限速下降机的设计,该设备由承载装置、缓冲器、紧急刹车装置、机械传动机构和液压阻尼系统等组成,设备通过液压系统的阻尼作用来实现缓降。此设备安装操作方便,可用于高楼逃生,也可用于矿井救援。     

高层逃生自救设备的研究与创新设计

首先对缓降器装置的研究现状进行了有效的分析,发现许多装置结构原理复杂、操作繁琐,未经专门的培训不能很好地掌握其操作方法,甚至还有部分产品需要电力驱动,断电时无法工作,然而这些在逃生中都是致命的限制因素。为了解决这些弊端,实现最有效的高层逃生,文中具体分析阐述了一款新型的高层逃生器。在设计中运用磁阻尼原理结合人机工程学数据,利用人体自身质量,通过机械机构的转换,产生减缓人体降落的阻力,最终使人体缓降安全着陆。其不仅可以用于缓降重物,也可用于紧急情况下的高楼逃生,有效地减少了人民群众生命和财产的损失。     

高楼失火逃生装置

介绍一种高楼失火逃生装置,最大特点是通过杠杆原理使负载转化为摩擦阻尼,从而使不同体重的人以近似匀速的安全速度着陆,并通过计算和实验验证其安全性。     

一种高层建筑应急逃生装置的研究

基于摩擦缓降和电磁阻尼原理,研究并设计制作了一款纯机械式高层建筑应急逃生装置。该装置采用单行程滑道式摩擦缓降原理,通过二级加速齿轮箱提高离心式摩擦减速器的转速,同时利用减速电机高速旋转产生电磁阻尼力矩进行减速制动,实现了摩擦力和电磁阻尼力双保险制动的功能,应急逃生缓降速度可控并能实现紧急制动。最后对样机进行了现场测试。测试结果表明该产品逃生策略新颖,安全性大大提高,纯机械式模块化结构,体积小,操作简便,安全可靠。     

基于摩擦原理的高楼自助逃生装置的设计

利用自行车摩擦片刹车原理,提出了一种基于控制摩擦力大小来减速的高楼自助缓降逃生装置的设计思路。在经过理论计算的基础上设计了样机。该逃生装置通过配重以及利用杠杆原理等方法来放大摩擦力,以此达到控制下降速度的目的,无需外力操控,可作为被困于高楼火灾、爆炸等困境的人们的自救逃生工具。     

一种液压阻尼式高楼逃生装置的设计

对逃生装置的关键技术进行研究,提出了一种液压阻尼式高楼逃生装置的设计方案.根据不同人群的需要,可利用自身体重的不同,该逃生器通过多个液压缸中的液体往复流动提供的阻力,从而达到不同人群以不同的速度稳定下降的目的.在设计过程中,首先利用Pro/E软件建立逃生装置的三维几何模型,然后利用Mathcad对装置中的关键部分进行了计算分析,最后加工制造实验装置,通过现场测试验证设计结果.     

摩擦式高楼逃生器的设计

论文提出了一种基于摩擦原理的纯机械高楼逃生装置。该装置设计了安装逃生器的专用支架和防止钢丝绳脱落的壳体,还设计了限制超速的自锁机构,使得高楼逃生更加快速安全、操作方便,老少皆可适用,适用各种体重,而且适用于复杂的外墙状况。该逃生器不需要外在动力,结构紧凑、简单实用,下降速度稳定,且造价较低。     

干摩擦条件下载荷动特性对摩擦面粗糙度的影响

在自行研制的环 -块磨损试验装置上研究了干摩擦状态下矩形波载荷特性对摩擦面粗糙度的影响 ,结果表明 :1随着磨程的进行 ,摩擦面粗糙度将达到一个稳定值—平衡粗糙度 ,其大小与摩擦面初始形貌无关 ;2当载荷波形占空比 φ较小时 ,平衡粗糙度 Rsq 对φ的变化敏感 ,且随 φ的增加而增加。当 φ足够大时 ,Rsq 几乎不随 φ而变化     

一体化智能型固体内耗仪的机械系统精度分析与提高

通过对MRS-2型一体化智能型固体内耗仪机械系统中倒扭摆的精度分析,从理论上揭示了固体内耗仪诸多系统中机械系统是内耗测量中的根本和核心所在,其精度是决定整个内耗仪内耗测量精度的关键,同时提出了应用激光二维扫描传感器实时检测与提高内耗仪机械系统精度的方法,填补了该领域的研究空白,具有一定的工程应用价值。     

摩擦副相互作用阻尼动力学特性初探

采用自行设计和制作的具有摩擦副且能自激振动的摩擦摆实验装置,在不同的工况下进行大量的实验,记录相应的实验数据,绘制出摩擦力矩、振幅等与电机转速的关系曲线图.选择代表性的实验数据进行理论分析,结果表明系统的正阻尼远远大于负阻尼,在摩擦自激振动的研究中不能忽略正阻尼的影响.同时还得出一些结论,为解决生产实际中的摩擦自激振动问题提供了一些有意义的理论依据.     

Evaluation of the coefficient of friction of rail in the field and laboratory using several devices

ABSTRACT

Accurate friction measurement is vital to apply appropriate friction management techniques to the wheel/rail interface. This work analyses different friction measurement techniques under a variety of conditions in the laboratory and the field. Tests have been carried out using a pendulum tester, hand-push tribometer, twin-disc machine and full-scale rig in the UK and Colombia for a variety of interfacial conditions and rail hardness. The pendulum has been found to be more sensitive to different conditions than the hand-push tribometer. This is due to the area that the pendulum sweeps being smaller, and so it can be more carefully controlled and therefore measure the surface condition being tested. This is in contrast to the push tribometer which needs a long section of rail to take a measurement. Twin-disc and full-scale rig creep curves show good agreement between each other.     

高精度固体内耗仪的机械系统检测研究

针对目前忽略对固体内耗仪机械系统的研究以及把固体内耗仪测控系统的测量精度作为整个内耗仪内耗测量精度的观点,从理论和工程实践上,论述了固体内耗仪机械系统中倒扭摆垂直精度对内耗测量的影响,揭示了固体内耗仪诸多系统中机械系统是内耗测量中的根本和核心所在,其精度才是决定整个内耗仪内耗测量精度的关键。     

An apparatus for the study of wear under dynamic loading conditions

A multipurpose wear testing apparatus has been designed, constructed and calibrated. The apparatus is primarily an impact wear testing device, but it may also be used for vibratory and oscillatory wear experimentation. The system utilizes a versatile displacement- and force-controlled device, which allows accurate control and measurement of the load cycles and their frequencies and the relative normal and transverse velocities between the wear surfaces as well as their time of contact. Features of this design permit testing at elevated frequencies and investigation of the effect of individual parameters on the wear process. These features include a facility to manipulate the system stiffness, the ability to control the impact and rotational velocities independently, feedback to maintain a constant nominal stress parameter, the ability to use spherical or cylindrical wear specimens and a method of applying the load and relative transverse motion in a constant, random or prescribed manner. The design facilitates modifications to include lubrication and environmental control, measurement of friction forces and fretting wear capabilities. Some initial results are included.     

Microsecond duration pressure pulse generator for in situ dynamically loaded SEM fracture studies

We describe a technique to impulse load small cylindrical specimens for in situ, real-time SEM studies of dynamically loaded fracture. Loading is done magnetically with a solenoidal coil of 10 mm length and 1 mm radius. The entire loading assembly fits on the SEM stage; there is no need for shock-isolated bellows apparatus. The only vacuum feedthrough required is an MHV coaxial bulkhead connection. A ballistic pendulum measurement gave a peak compressive pressure of ～20 MPa, with a pressure pulse width of 1.33 μs. Pressures > 80 MPa can easily be generated. Using this device we have obtained real-time SEM movies of dynamically loaded fracture of rosin.     

A Study of the Static/Kinetic Friction Behavior of PTFE-Based Fabric Composites

Three different polytetrafluoroethylene (PTFE)-based fabric composites were prepared. The static/kinetic friction behaviors of these composites under different loads and speeds were studied. A 3D laser microscope and profile measurement apparatus were used for analysis of the morphology and weave structure of the composites, and the contact temperature of these composites under different loads and speeds was monitored continuously using a high-precision thermal resistor. In addition, a dynamic mechanical analysis (DMA) apparatus was used to explore the thermal and mechanical properties of PTFE-based fabric composites. The results demonstrated that speed/load, weave structure, and fiber form have an important influence on static and kinetic friction behavior of the fabric composites. Generally, the static friction coefficient is greater than the kinetic friction coefficient, except when considering light load conditions. Under light load conditions, the static friction coefficient is equal to the kinetic friction coefficient. In addition, the kinetic friction coefficient first increased and then decreased with increased speed, but the static coefficient increased first and then remained at an almost constant value. At all sliding speeds, the static and kinetic friction coefficients of tape yarn composites are better than those of the multifilament yarn composites. Weave structure has no effect on the static friction coefficient, but it has a significant influence on the kinetic friction coefficient.     

A new fretting fatigue testing machine design,utilizing rotating–bending principle approach

Fretting fatigue is a phenomenon which occurs when two parts are contacted to each other and one of those parts or both are subjected to cyclic load. Fretting decreases fatigue life of materials drastically by half or even more. Therefore, investigation of fretting fatigue life of materials is an important subject. Fretting fatigue tests are usually performed using universal hydraulic testing devices. In this work, a rotating bending apparatus for fretting fatigue test is introduced in which the cyclic load is provided by an adjustable eccentric load. The apparatus called RBFF machine which is the abbreviation of rotating bending fretting fatigue. The eccentric load is measured by load cell. The coefficient of friction and fretting load are measured by foil strain gauges using a Wheatstone bridge configuration. The performance of the machine is verified with doing a comparison between fatigue lives of a number of AL7075-T6 alloy samples on a Shimadzu rotating bending fatigue testing machine and RBFF. The results shows very close assent between the operations of the two testing rigs. The main privileges of RBFF are its simplicity with respect to universal devices, cheapness and, coefficient of friction (between pads and specimen) evaluation during the test. The RBFF also has the capability of being used for any other soft and hard metals. It can be advanced further for high and low temperature.