典型车用旋转密封材料的摩擦磨损和润滑特性研究

发布时间：2018-11-14 21:21

【摘要】：在车辆传动领域,旋转密封是一种特殊形式的端面动密封件,其作为关键元件,广泛应用于内部含有液压控制的旋转执行部件中,如湿式离合器、制动器以及液力变矩器。而旋转密封的性能直接影响到传动装置的整体性能,其一旦发生密封失效,会导致传动装置的整体故障。课题以车用旋转密封为研究对象。典型车用旋转密封的材料有铸铁、PTFE和PEEK,为保证密封环的工作性能,减小摩擦功率损失与对偶面磨损,改善润滑状态,通常在密封环工作端面上加工有沟槽,由于铸铁材料较PTFE和PEEK等聚合材料弹性模量较大,而且浅槽常用的激光加工法不适合用在聚合材料的加工,所以常常在铸铁材料的密封环的端面上加工深度为微米级的浅槽,而在PTFE和PEEK材料的密封环上加工深度为毫米级的深槽。对端面加工有浅槽的旋转密封进行了流体动力润滑计算研究,而对端面加工有深槽的旋转密封端面轴向变形开展了初步的探究。在计算深槽密封环端面轴向变形时,将密封环所受的力分解为轴向、径向和切向分别求解计算,通过傅里叶三角级数展开、三角函数叠加等方法得到了周期性的深槽密封环端面变形表达式。构建了旋转密封轴向受力平衡方程,建立了旋转密封混合润滑状态下的油膜承载力和粗糙峰承载力的计算模型,通过仿真计算得到了不同工况下的密封环的润滑油膜厚度、油膜承载力和粗糙峰承载力。开展了流体润滑验证试验,油膜厚度测量实验结果表明,浅槽旋转密封件工作时能够产生流体动压力和微米级的润滑油膜。通过大量的盘销试验,开展了边界润滑条件下典型旋转密封件材料的摩擦磨损特性试验研究,试验结果表明,三种典型旋转密封材料的磨损率都随着粗糙峰承载力的增加而增大,而与转速的关系较复杂。通过显微镜观察三种材料磨损后的摩擦面状况,表明三种材料磨损形式主要以磨粒磨损和黏着磨损为主。结合典型旋转密封材料磨损实验和流体润滑油膜厚度试验的实验数据,相继拟合得到了铸铁材料、添加15%碳纤的PTFE材料和PEEK材料的磨损率与密封环旋转速度和作用载荷的拟合曲面公式。
[Abstract]:In the field of vehicle transmission, rotary seal is a special type of end face dynamic seal. As a key element, it is widely used in rotary actuator with hydraulic control, such as wet clutch, brake and hydraulic torque converter. The performance of rotary seal directly affects the overall performance of the transmission device, once the seal failure occurs, it will lead to the overall failure of the transmission device. The object of study is vehicle rotary seal. In order to ensure the working performance of seal ring, reduce friction power loss and dual surface wear, improve lubricating condition, PTFE and PEEK, usually process grooves on the working face of seal ring. Because cast iron materials have larger elastic modulus than polymeric materials such as PTFE and PEEK, and the laser processing method commonly used in shallow grooves is not suitable for the processing of polymeric materials, it is often used in shallow grooves with micrometer depth on the end surface of the sealing ring of cast iron. On the sealing ring of PTFE and PEEK materials, deep grooves with a depth of mm are processed. The hydrodynamic lubrication calculation of the rotary seal with shallow groove was carried out, and the axial deformation of the end face of the rotary seal with deep groove was studied. In the calculation of axial deformation of the end face of the deep groove seal ring, the force acting on the seal ring is decomposed into axial, radial and tangential directions, respectively, and is expanded by Fourier trigonometric series. The periodic expressions for the deformation of the end face of the deep groove seal ring are obtained by the trigonometric function superposition method. The axial force balance equation of rotary seal is established, and the calculation model of oil film bearing capacity and rough peak bearing capacity under mixed lubrication state of rotary seal is established. The lubricating oil film thickness of seal ring under different working conditions is obtained by simulation. Oil film bearing capacity and rough peak bearing capacity. The oil film thickness measurement results show that the hydrodynamic pressure and micron lubricating oil film can be produced when the shallow groove rotary seal works. Through a large number of disk pin tests, the friction and wear characteristics of typical rotating seal materials under boundary lubrication are studied. The experimental results show that, The wear rate of the three kinds of typical rotating sealing materials increases with the increase of the rough peak bearing capacity, but the relationship between the wear rate and the rotational speed is more complex. The wear surface of the three materials was observed by microscope. The results show that the wear patterns of the three kinds of materials are mainly abrasive wear and adhesive wear. Combined with the experimental data of the wear test of typical rotary seal material and the thickness test of fluid lubricating oil film, the cast iron material was obtained one after another. The fitting surface formula of wear rate of PTFE material and PEEK material with 15% carbon fiber and rotating speed and acting load of seal ring.
【学位授予单位】：北京理工大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：U463.2

【相似文献】