消除通风机轴承箱漏油的措施

介绍了在风机轴承箱填料密封的基础上,增加内装旋转轴唇形橡胶密封圈后的辆封改进方法,同时对改进前后的密封效果加以比较     

减速器出轴密封装置的改进设计

分析总结了GB9877.1-88《内包骨架旋转轴唇形密封圈》、JB／ZQ4245-86《油沟式密封槽》的密封特点和国家对机械产品的环保要求，针对某型减速器的出轴密封装置进行了CAD优化改进设计。     

一种基于反向泵送机制的唇形密封解析模型

旋转轴唇形密封应用广泛,泵送率和摩擦力矩是评价密封性能的主要依据。基于反向泵送机制,提出一种研究唇形密封性能的解析模型。基于静态力学特性有限元仿真和粗糙峰微单元流场分析,结合混合润滑模型计算结果,建立泵送率和摩擦力矩的计算公式,通过台架实验确定公式中的待定常数。采用解析公式计算其他唇形密封泵送率和摩擦力矩,计算结果与实验测量值、数值仿真结果具有很好的一致性。该解析模型计算简单,可以用于唇形密封的工程设计与分析。     

油封在商用汽车变速器总成中的应用设计探讨

漏油是汽车变速器中较常见的故障,改进是一个长期的课题。主要介绍了商用汽车变速器总成中常用的旋转轴唇形油封的组成、功用及密封原理,重点对与油封相配合的轴和孔的配合部位设计要点进行了探讨,从设计源头提升变速器总成的密封性能。     

消除通风机轴承箱漏油的措施

简介了风机轴承箱在填料密封的基础上,增加了内装旋转轴唇形橡胶密封圈后的安装及其工作原理和方法,同时对改进前后的密封效果作以比较,阐述了经过几年的实际应用,证明这种方法具有良好的密封效果。     

旋转轴唇形密封圈技术要求和使用要点

正旋转轴唇形密封圈是工程机械常用配件。全面了解旋转轴唇形密封圈的技术要求和使用要点,是做好工程机械维修工作的重要环节。1.结构和原理(1)结构旋转轴唇形密封圈主体由橡胶制成,其外径部位设有金属骨架。金属骨架的作用是增强密封圈强度,以便牢固地安装在座孔中。旋转轴唇形密封圈有6种型式,即内包骨架型、外露骨架型、装配型、带副唇内包骨架型、带副唇外露骨架型和带副唇装配型。旋转轴唇形密封圈内径为弹性密封唇,其在     

面向产品可持续设计的关键功能模块识别方法

为实现可持续产品的快速开发,提出了面向产品可持续设计的关键模块识别方法。将传统的顾客需求扩展为面向可持续的环境,经济,社会需求,基于质量功能配置的展开过程,将产品的可持续需求依次转换为产品的技术特性和功能模块,并确定面向产品可持续设计的关键功能模块。基于全生命周期分析,通过需求调研,获得质量功能配置的可持续环境需求输入,环境需求的权重根据生命周期阶段与环境要求标准和环境评价指标的敏感度及相关性分析,得到不同生命周期阶段对环境影响的贡献大小,并综合调研获取的重要度得到;经济和社会需求及其权重则是通过调研并集成层次性分析法、KANO模型获得。以带材纠偏控制系统的关键模块识别过程为例,验证了所提方法的可行性及合理性。     

基于压力-状态-响应框架的产品可持续设计指标体系研究

为规范可持续设计便于系统化操作和使用,准确全面地实现产品的可持续设计,对设计指标进行分析,构建面向产品生命周期的多维度可持续设计指标体系,以可持续设计的环境性、经济性、社会性和技术性为目标层,以产品生命周期的5个阶段为时间层,对压力-状态-响应(Pressure-State-Response, PSR)3方面进行逻辑分析,获得产品可持续设计指标,并依据可持续设计在环境、经济、社会和技术4个维度分类,从而构建多维度可持续设计指标体系。PSR框架思想与产品生命周期有效结合,为可持续设计指标体系的科学构建提供了依据,根据该设计指标体系进行产品开发而得到的方案可在全生命周期各阶段的4个维度上具有可持续性,从而实现产品的可持续设计。以某咖啡机为例,对可持续设计指标的实际应用效果进行了验证。     

迷宫型轴承保护器

<正> 唇形密封容易磨损,特别是在高温、高压、磨蚀或腐蚀环境下更是如此。因此要避免旋转轴轴承润滑剂被污染是困难的。最近,美国Durametallic公司研制的一种轴承保护器优于唇形密封,使泵的使用寿命延长三到五倍。该装置(如图)主要有     

表面纹理对旋转轴唇形密封性能的影响

在唇形密封圈唇端两侧设置整齐排列的圆形、正方形和等边三角形3种凹坑纹理形式,建立具有表面纹理的旋转轴唇形密封圈的有限元模型,并分析获得密封面静态接触压力和变形系数矩阵;建立综合考虑混合润滑和空化及表面纹理形状影响、耦合流体场和弹性变形场的唇形密封圈接触区域密封数值计算模型,并建立集有限元分析与数值计算于一体的唇形密封圈接触区域泵吸率计算流程。计算结果表明:表面纹理结构使得密封唇与轴的接触压力相对下降,且有效地增大唇形密封圈的膜厚并改善泵吸效果;相较于圆形和正方形纹理,三角形纹理对唇形密封圈的改善效果最佳。但表面纹理结构在改善密封区域润滑状态的同时,也造成密封动态压力的波动,且三角形纹理的影响更显著。     

三种型式轴封的摩擦功耗测定与比较

摩擦功耗是评价轴封节能与否的重要指标。利用MMU-2摩擦磨损试验机对3种结构型式轴封即填料密封、机械密封和360度旋转式组合密封的摩擦功耗进行了测定。试验结果表明:3种型式轴封的摩擦功耗随转速的增大而增大,填料密封摩擦功耗最大,机械密封摩擦功耗次之,360度旋转式组合密封摩擦功耗最小;不同材料的填料密封的摩擦功耗不同,碳纤维填料密封和四氟填料密封摩擦功耗基本接近,并且远远低于芳纶填料密封。该结果为正确选择轴封提供了重要的参考依据。     

旋转轴唇型密封圈的寿命预测研究

提出基于ABAQUS软件和疲劳分析软件FE-SAFE预测旋转轴唇形密封圈寿命的方法.以某型号减速器中的输入轴与轴承端盖间的旋转轴唇形密封圈为研究对象,通过构建预紧状态下旋转轴唇形密封圈的有限元模型,获得旋转轴唇形密封圈的过盈量和理论接触宽度与唇口最大接触压力之间的关系曲线;根据ABAQUS获得的应力,并结合材料应力-循...     

曝气机主轴浮动端面密封的设计

曝气机广泛应用在城市污水和工业废水处理氧化沟工艺技术中,其水平转动轴一般采用传统的旋转唇形密封。对曝气机水平转动轴旋转唇形密封泄漏的原因进行分析,指出唇形密封的密封面微观凹凸体的变形和密封唇的倾斜是造成密封失效的主要原因。设计浮动端面密封,该密封的动环和静环均为浮动环,密封浮动性好,对水平转动轴的支承轴的同轴度和偏心不敏感,密封效果好。通过大量的现场使用证明,曝气机水平转动轴采用浮动端面密封结构方法是可行的。     

How do the temperature,angular velocity and electric fields affect mechanical and electrokinetic phenomena in a friction junction?

In the friction junction, that is in a rotating metal shaft–base oil–rotary lip seal system, dynamic phenomena occur which are of mechanical and electrical nature. During the shaft׳s rotation the components of an oil film – a gap between the surfaces of a shaft and a lip of a rotary lip seal – are caused to move about within the film under the action of a centrifugal force. The relative movement of different particles and molecules in turn brings about tribocharging and results in establishing an electric field within the gap. The field and so acting the Coulomb force also affect the distribution of charged species as does the van der Waals attractive force. To analyze the effect of the above factors as well as the temperature of oil in the gap measurements of the shaft׳s braking torque and the voltage between the rotating metal shaft and a stiffening ring of a lip seal for different ranges of the base oil׳s temperatures and of the shaft׳s angular velocities are performed. In the experiments the synthetic PAG (polyalkylene glycol) and PAO (polyalphaolefin) base oils and a fluorocarbon rotary lip seal are used.     

A Transient Mixed Lubrication Model of a Rotary Lip Seal with a Rough Shaft

A rotary lip seal, widely used in machines containing rotating shafts, is usually protected from mechanical and thermal damage by a thin film of lubricant under the lip, separating the lip and the shaft surfaces. However, under some transient conditions such as those during startup and shutdown, the fluid film is not fully established or it breaks down, and the seal operates in the mixed lubrication regime. To simulate such cases, a transient mixed lubrication analysis has been developed. It generates predictions of such seal operating characteristics as load support sharing between hydrodynamic and contact pressure, contact and cavitation area ratio, the reverse pumping rate, and the average film thickness. In most previous numerical simulations of the rotary lip seal, the shaft surface is modeled as perfectly smooth. In the present study, a more realistic shaft surface with asperities is used, and the effect of the shaft surface roughness on the behavior of the seal is investigated.     

Shaft roughness effect on elasto-hydrodynamic lubrication of rotary lip seals: Experimentation and numerical simulation

Numerical analyses of the isothermal elasto-hydrodynamic lubrication (EHL) have made considerable advances in order to identify the most important features in the successful operation of rotary lip seal, and the results have shown a good agreement with experiments.Most of the models previously published are capable of predicting the combined effects of thin film through deformed lip and rotating shaft, but they assume a smooth surface of the shaft. Although this assumption is only verified for shaft roughness much smaller than that of the seal lip, it is the best solution to avoid a transient model.First, the present study describes an experimental work that provides a basis upon which a numerical EHL model of rotary lip seal is constructed by taking into account both the shaft and lip roughness. After confirming the validity of the current model by comparing experimental with numerical results, simulations have been performed and have underlined the effect of shaft roughness amplitude and profile on the rotary lip seal performance. It is shown that for shaft roughness beyond half of the lip roughness, the seal may leak.     

旋转轴唇形密封件磨损仿真分析

使用有限元分析软件Abaqus对旋转轴唇形密封件的磨损进行模拟,通过UMESHMOTION用户子程序来实现密封件的动态磨损过程和控制局部区域的网格自适应划分,并基于磨损因子模型来控制橡胶的磨损速率,得到了密封件唇口轮廓形状以及接触压力随时间的演化规律。通过计算所得的主唇口磨损深度与实验值进行对比,验证了仿真方法的有效性。结果表明:密封件唇口磨损可分为初期的快速磨损阶段和之后的稳定磨损阶段;在磨损初期磨损速率较大,密封圈与轴之间的过盈量减小,最大接触压力先迅速减小,而后变化逐渐趋于缓慢;随着磨损时间的增加,唇口轮廓逐渐变得平缓,并且防尘唇的磨损程度要比主唇口更高,说明磨损主要发生在空气侧。     

An unsteady mixed soft EHL model, with application to a rotary lip seal

A rotary lip seal usually operates with full-film lubrication. However at low speeds, such as those encountered during startup and shutdown, mixed lubrication occurs and asperities on the lip contact the shaft. To simulate this condition, a mixed soft EHL model has been constructed. The fluid mechanics of the lubricating film is described by a Reynolds equation that can handle interasperity cavitation. The bulk deformation of the lip is computed using influence coefficients, while the junctions between the asperities and the shaft are modeled as Hertzian contacts. Since the shaft is rough, the flow is unsteady and an unsteady analysis is required. The model shows how the shaft roughness affects such seal characteristics as load support, contact load ratio, contact area ratio, cavitation area ratio, reverse pumping rate and average film thickness.     

Base Oil and Its Blends with ZDDP and Their Effect on Tribocharging,Braking Torque and Electrical Double Layers in a Friction Junction

The paper presents the results of experiments on tribocharging of a blend of mineral-base oil and different zinc dialkyldithiophosphate (ZDDP) contents in a friction junction. A friction junction is constituted by a rotating shaft, a film of pure base oil, or its blend with the ZDDP, and a rotary lip seal, which is the interfacial system as a whole. Experiments were carried out on the specially built experimental facility to be a simplified model of an engine’s crankcase (or sump) in whose interior an earthed metal shaft rotated at given angular velocities. Electric potential of a stiffening ring of a lip seal, which is a measure of tribocharging, was measured directly with an electrometer. The stiffening ring’s potential is induced by charge in the film of pure base oil or the ZDDP-oil blend and is a function of the oil temperature for different angular shaft velocities and the ZDDP contents. The potential is presented in the form of some characteristics. Also the effects of an external DC electric field on the braking torque of the rotating steel shaft were examined for a range of oil temperatures, angular velocities, and ZDDP contents, and here the torque is presented for one temperature and different DC voltages of both polarities. An analysis of the research results obtained permitted us to show how the ZDDP content in a blend with the base oil tested, angular velocity, and oil temperature could affect tribocharging in the interfacial systems: the rotating shaft-oil and oil-lip seal, as well as the whole oil film in between and both electrical double layers (EDLs) at the surfaces of a shaft and of a lip of a rotary lip seal in the friction junction.