大型水泵导轴承端面密封研究

从理论上推导了大型水泵油润滑导轴承端面密封泄漏量计算公式。通过实例计算了端面密封的泄漏量和排漏水量,根据结果分析了造成油润滑导轴承浸水受损的端面密封失效原因。提出了保证端面密封可靠性的措施。     

钳盘式制动器制动活塞异型密封性能研究

提出将异型密封结构形式应用于汽车钳盘式制动器活塞的密封中,根据密封界面流体动力学中的弹性流体动压模型,建立制动液油膜的准一维流动的雷诺方程,给出制动活塞往复运动时的油膜厚度和泄漏量的计算方法。利用Fluent软件平台,对比分析制动活塞异型密封梅花形密封圈和标准型O形密封圈在往复运动过程中油膜厚度和制动液泄漏量受摩擦因数、制动压力、压缩量等因素影响规律。结果表明:梅花形密封圈和O形密封圈的油膜厚度随着摩擦因数的增大而增大,随着制动液压力和压缩量的增大而减小;但异型密封梅花形密封圈在相同的摩擦因素条件下有更好的润滑性能,泄漏量小,其油膜厚度相对于O形密封圈变化过程比较缓慢,降低了对密封圈的磨损;在压缩量较大的情况下,制动活塞梅花形密封圈的防泄漏能力大于传统的标准密封结构O形密封圈。制动活塞采用异型密封结构可有效减小密封圈的磨损量,有较好的防泄漏能力,能够实现良好的自密封。     

氨压缩机干气密封失效事故分析

从机组实际状况看,轴瓦距离密封隔离梳齿很近,运行时靠近密封处油位过高甚至漫过梳齿,润滑油经轴瓦后呈喷射状快速流出,对隔离梳齿阻油效果存在很大影响,导致密封润滑油穿过隔离梳齿进入密封区域,最终造成干气密封失效。对干气密封隔离密封处改造,包括并紧螺母上加密封圈、并紧螺母设计为台阶结构、压紧套上加密封圈、并紧螺母加甩油结构、梳齿加集油槽、压紧套加台阶等。结果显示,未发现干气密封的一级泄漏气、二级泄漏气及排凝口带油现象,基本消除润滑油进入密封的通道。     

大型水泵导轴承应用研究

通过调查，指出了大型水泵导轴承常见的故障形式，分析了故障发生的原因，提出了导轴承的选用原则和提高其可靠性和耐久性的途径和方法。提高金属油润滑轴承的密封性能和排漏水能力，非金属清水润滑轴承采用护管式结构，提高泵机组和进水流道设计、制造、施工和安装水平，减小导轴承荷载，可以提高大型水泵导轴承的可靠性和耐久性。     

O形密封圈的妙用

橡胶O形密封圈除了起密封作用以外,还可起另一个作用。我厂一台控温转鼓轴头采用骨架油封进行密封,由于转鼓内的液体具有较强的腐蚀作用,致使骨架油封的自紧弹簧经常被腐蚀,不到一个月即损坏。产生漏水,严重地影响了轴承的使用寿命。换用U形密封圈由于自紧效果不好,使用寿命也不长。最后我们用O形密封圈代替骨架油封中的自     

某核电设备冷却水泵轴承箱缺陷分析及处理

某核电站设备冷却水泵调试运行期间,出现泵驱动端和自由端恒位油杯油位低、启动时恒位油杯中润滑油吸入轴承箱导致轴承箱油位高(视油窗显示100%)、润滑油从轴承箱端迷宫密封处泄漏且轴承箱温度高等缺陷。随后,对设备冷却水泵诸多缺陷开展了专项治理工作,经对该泵轴承箱进行改造,消除了轴承箱迷宫密封漏油现象,为以后处理泵轴承箱恒位油杯油位低、启动时润滑油吸入轴承箱、轴承箱端迷宫密封漏油、轴承箱温度高等缺陷提供了参考。     

表面粗糙度对矩形动密封特性的影响

基于耦合了密封圈的弹性变形、流体动力分析和过盈接触的密封性能数值计算流程,利用Matlab 软件编程实现矩形动密封特性的数值计算,得到矩形密封圈的油膜厚度、泄漏量及摩擦力等密封性能参数,分析表面粗糙度对矩形密封圈的润滑状态和泄漏量的影响。结果表明：往复运动速度一定时,随着密封圈粗糙度的增加,密封偶合面的润滑状态由流体润滑转变为润滑润滑状态,密封的泄漏量也呈几何式增加,说明粗糙度对密封圈的工作寿命和密封性能有较大的影响;往复运动速度也是影响矩形密封圈密封性能的关键工作参数之一,密封压力一定时,随着粗糙度的增加,不发生泄漏的临界速度降低。     

一体式充气减振器的分析与研究

分析目前所用充气减振器存在的问题,并研究开发了一体式充气减振器。将原减振器的封头、导套和储油缸筒做成一体式缸体,从根本上杜绝封头和导套处的泄漏问题;在活塞杆与导套之间不使用Y形密封圈而用V形密封圈三道一体密排,以解决动密封处的泄漏问题;设计了充油头及充气气囊,以解决减振器一次使用报废的问题,提高其使用寿命。     

多相介质泵用高压密封设计及性能分析

针对多相介质泵用机械密封运行特点,为避免介质含气量大范围波动而影响密封端面润滑膜的稳定性,开展高压双端面机械密封结构和端面槽型设计,通过变形校核证明结构设计合理。建立密封端面深槽流体润滑模型,采用数值计算方法进行求解,分析不同开槽面积比的圆弧型槽的端面泄漏量、开启力等主要密封性能随工况参数的变化规律。结果表明：高压状态下,密封端面开深槽能有效改善端面润滑状态;端面泄漏量和开启力随着开槽面积比的增大而变大,同时压力越大,端面泄漏量和开启力也越大,但转速对端面泄漏量和开启力的影响不大。对设计的密封进行台架性能试验验证,获得的密封端面泄漏量变化规律与数值计算结果趋势保持一致。     

保护 一定要接触吗？ 一种新型非接触式轴承保护器

在机床行业有大量的轴承在使用,派克的ProTechTM轴承保护器可以起到双向密封,以免润滑油泄漏和外部污染物的侵入。 ProTechTM轴承保护器的特点是其高效的迷宫结构,这比通常的轴承保护器所用的内部的O形圈或密封圈有更好的密封性能(图1)。图1符合IP55、IP56、IP66、IP69K 和API 610(IEEE 841标准,由 UL测试)。     

Experimental Investigations and Field Applications of Oil-Film-Lubricated Mechanical Face Seals with Spiral Grooves

The oil-film-lubricated mechanical face seal described here is a hydrodynamically lubricated, noncontacting, mechanical face seal with zero leakage. On the basis of systematic theoretical analyses, research on design methods, and experimental investigations, many field applications have been made. The experimental investigations include test rig development; long-time high-speed running tests; frequent start-up and shut-down tests; measurements of the seal leakage, face temperature, and characteristics of the self-circulating screw pump; observation, measurement, and solution of interface wear, and so on. Until now, this new seal design has been successfully applied in more than 40 high-speed turbocompressors in the oil refinery and petrochemical industries, achieving zero leakage and long operation. These seals are all designed with different face spiral-groove patterns, structure arrangements, and supporting systems.     

新型矿用排水泵入口段口环密封结构优化研究

以某型号矿用排水泵入口段口环密封为研究对象,采用数值仿真方法,研究排水泵迷宫密封内部流动特征,分析迷宫密封结构尺寸与形状对其泄漏量的影响。结果表明:迷宫的间隙尺寸对密封性能的影响最大,间隙宽度和节流齿宽度的变化将导致泄漏量的大幅变化;相比直齿结构迷宫密封,异形齿结构有利于湍流充分发展,从而可以提高密封性能;通过分析复杂迷宫密封的内部流场,得到适用于排水泵的优化的迷宫密封结构。     

大尺寸O形丁腈橡胶圈动密封性能测试分析

为研究大尺寸O形橡胶密封圈端面动密封性能,研制适应于大尺寸O形橡胶圈的动密封性能测试平台,测试水介质条件下绝对压力在15～600 kPa范围内O形橡胶密封圈端面动密封性能.基于正交试验设计,研究不同介质压力、压缩量(0.75～1.25 mm)和转速(5～50 r/min)下内径600 mm(截面直径10 mm)的丁腈橡...     

浆料泵轴密封结构的改进

利用设备的振动分析对螺杆泵密封失效原因作诊断,并将原有的填料密封改造为橡胶油封、迷宫密封及填料密封的组合形式,彻底解决了泄漏问题。     

Theoretical Analyses and Design Guidelines of Oil-Film-Lubricated Mechanical Face Seals with Spiral Grooves

The oil-film-lubricated mechanical face seal is a kind of pure hydrodynamic lubricated noncontacting mechanical face seal with zero leakage. On the basis of systematic theoretical analyses, the design calculation formulas under zero-leakage condition for mechanical face seals with different spiral groove patterns, including double-row spiral grooves such as splay pattern and single-row spiral grooves, are derived. The effects of groove geometry including number of grooves, balance ratio, spring force, rotating speed, and differential pressure on the seal performance are discussed in detail. Finally, the design guidelines of this kind of seal with zero leakage and no wear are put forward. The seals designed according to the guidelines can withstand the pressure disturbance and speed change by means of a slight change of oil-film thickness. Seals developed according to the design guidelines have been tested on a test rig in detail and applied successfully in high-speed turbocompressors of the oil refinery and petrochemical industries.     

Wear study of field worn clutch actuators and evaluation of a model test

Pneumatic clutch actuators, employed in trucks, have been investigated. The surfaces of the inside of the anodised aluminium cylinders, of the lip seals and of the guiding rings have been studied by SEM and optical microscopy. For most of the actuators no significant wear was revealed. However, one actuator, with leakage problems, was severely worn. An extensive amount of scratches was found on the cylinder surface, the thickness of the guiding ring had decreased and large parts were missing from the lip seal. A possible explanation is that particles have entered the system thus altering the contact conditions. A test setup was developed to investigate how particles present in the system affect the wear. A part of the piston, with lip seal and guiding ring, slides against a part of the anodised aluminium cylinder in a back- and forward motion. Pure silicone grease lubricated tests resulted in no wear. Tests with added dust particles resulted in distinct scratches on the aluminium surface and embedded particles in the guiding ring and the lip seal. These tests provide results in good agreement with the wear revealed in the investigations of used actuators and support the theory that wear is caused by particles.     

Performance of the Coned-Face End Seal with Regard to Energy Conservation

The effect of a face coning on seal performance, especially energy losses as indicated by a torque, were studied by comparing torque, face temperature, leakage, and wear of a conventional, widely used flat-face seal with three coned-face seals. Experimental evaluation was performed at rotation speeds to 8000 rpm, with pressures to 2758 kPa (400 psig), using a petroleum-base turbine oil. Axial movement of the mating seal parts was recorded using a digital data acquisition system. The height of the convergent-type cone on the face of the tungsten carbide primary ring ranged from 0.51 μm (20 μin) to 5.6 μm (220 μin) over the 3.175-mm to 6.36-mm (0.125-in to 0.25-in) face width. The torque of the coned-face seal, balanced lo 76.3 percent, was an average 42 percent lower, the leakage eleven limes higher than that of the standard flat-face seal. Reducing the balance to 51.3 percent by decreasing the face width of the coned-face seal resulted in lowering the torque by an additional 44 percent and increasing the leakage 12 to 230 times, depending on the seal shaft speed. No measurable wear was observed on the face of the coned seals. All four seals operated in the stable region of the stability map.     

渣浆泵双端面机械密封密封环热力耦合分析

针对磷酸厂渣浆泵机械密封因端面变形而导致的使用寿命缩短问题,以渣浆泵背对背型双端面机械密封密封环为研究对象,采用整体法,根据实际工况建立密封环热力耦合三维计算模型,研究密封环温度场分布及端面变形情况,分析不同工况下密封环热力变形对机械密封正常工作的影响.结果表明:密封环最高温度出现在静环内侧,且温度沿径向朝静环外侧逐渐...