脱氢压缩机组轴瓦失效分析

在对脱氢用离心压缩机组解体大修时发现其滑动轴承瓦面合金大面积脱落。采用材料性能测试、扫描电镜观察、金相检验和氢含量测定等方法对该轴瓦进行失效分析并进行流体动压润滑理论计算。结果表明：该型轴瓦失效的主要原因为氢气渗入材料。同时,氢鼓泡和氢致开裂的存在降低了轴瓦上巴氏合金与基体的结合强度及合金的疲劳强度,进而引起轴瓦的疲劳失效。另外,轴瓦的局部过热和转子不对中加速了轴瓦失效。     

动机主轴瓦失效分析及解决方案

发动机轴瓦失效是常见的发动机故障之一,严重影响着发动机的正常工作。针对某发动机主轴瓦在拉缸试验后出现合金层咬粘、脱落等失效问题,通过对主轴瓦进行理论计算、金相检验和对比试验,得出了曲轴平衡块的设计缺陷是导致该主轴瓦失效的主要原因。最后,通过将曲轴的四平衡块改为八平衡块,较好地解决了发动机主轴瓦拉缸试验后合金层失效的问题。     

660 MW发电机励端轴瓦绝缘失效故障处理

发电机励端轴瓦绝缘失效将阻碍机组安全稳定地运行,产生轴电流导致危害,为避免该问题产生,须在日常检修作业中加强对发电机励端轴瓦绝缘失效故障检查。基于此,该研究以某QFSN-660-2-22B型号660MW发电机为研究对象,探究其励端轴瓦绝缘失效故障形式及原因,对故障原因深入分析,探究该发电机产生励端轴瓦绝缘失效故障的主要原因,并以此为依据提出针对性处理措施。     

轴瓦材料工业化生产技术综合分析

轴瓦是柴油机重要的零件之一，轴瓦—旦失效，轻则影响柴油机的运转，重则造成曲轴断裂，机体报废。中速大功率柴油机的轴瓦大都采用薄壁、双层金属或三层金属结构。国产内燃机车的轴瓦大都采用铝锡20铜—钢双金属材料，这种材料具有很好的减磨性能，能与球墨铸铁、42CrMO钢曲轴很好匹配，承载疲劳强度为中上等。     

核电站大型巴氏合金轴瓦失效分析

利用光学显微镜、扫描电镜和能谱等分析手段,对巴氏合金轴瓦表面多次发生粘结和开裂进行了检验和分析。结果表明,在巴氏合金层中存在着组织分层,化合物相呈区域性偏析和聚集,轴瓦结合面附近存在大量疏松、孔洞等浇注工艺不当所形成的铸造缺陷;加之结合面附近背底金属中氢含量较高,轴瓦长期在一定温度和应力下工作,氢的不断扩散和聚集最终在巴氏合金表面形成氢鼓泡。上述缺陷的存在,使轴瓦在运行过程中易造成应力集中导致裂纹的萌生和扩展。最终造成局部润滑条件恶化而导致粘结和开裂失效。     

船舶柴油机轴瓦损坏故障分析

轴瓦损坏是发电柴油机的常见故障,本文从轴瓦损坏的形式和机理出发,分析了故障产生的原因。     

30MW汽轮机组3号瓦振动大的原因分析处理

介绍国电友谊生物质发电有限公司一台由青岛捷能汽轮机集团股份有限公司生产的机组,在启动过程中3号轴瓦振动超标的情况,分析了3号轴瓦振动超标的异常情况,提出了解决振动的措施。     

船舶柴油机轴瓦烧熔事故分析

本文通过分析轴瓦烧熔的原因和影响因素，从技术与轮机资源管理学的角度分析了船舶柴油机轴瓦烧熔事故的原因。     

在锡——铝合金轴瓦上电镀铅——锡合金工艺的研究

一、前言对任何给定用途的轴承材料的选择,一定是综合考虑表面性能、强度和耐蚀性。七十年代,我国轴瓦行业普遍采用含锡20%的高锡轴承合金。此种轴承材料不需镀涂减摩层便可直接使用。由于近年来,国际市场上锡的价格猛涨,而我国锡资源又很短缺,因此,七十年代末至八十年代初,我国试验研究成功含锡6%的Sn—Al合金轴承材料。为了把我国试制的这种合金轴瓦应用于     

从膨胀机事故论膨胀机的控制

深圳南华气体有限公司一套 170吨 /天空分液化装置 ,由于错误地加了一条旁通的临时连接气管 ,使得在断电的情况下保护失灵 ,造成膨胀机轴瓦烧坏。另外 ,膨胀机轴瓦油箱设计也存在问题。分析了事故的原因 ,并进行了改进。     

球磨机滑动主轴承重要参数的选取

讨论了球磨机主轴承宽径比L／D,中空轴轴颈的轴肩与轴瓦两侧面预留间隙值,轴瓦与中空轴轴颈间的配合侧隙,轴瓦与中空轴轴颈的配合接触角以及轴瓦与瓦座的配合接触面对球磨机滑动丰轴承承载能力和轴瓦磨损、发热的影响,并对它们的选取进行分析。     

Failure Investigation of a Locomotive Turbocharger Main Shaft and Bearing Sleeve

A failure investigation was conducted on a locomotive turbocharger main shaft and a bearing sleeve which had been assembled with the main shaft. The fracture of the main shaft took place at a sharp edged groove between two journals with different cross-sectional areas. The dominant failure mechanism of the main shaft was low-cycle and rotation-bending fatigue. Wear failure occurred on the bearing sleeve through a mixed mode of abrasive and adhesive wear. Detailed metallurgical analysis indicated that the bearing sleeve and the journal surface assembled with the sleeve had been subjected to abnormally high temperatures which led to increased friction between the bearing sleeve and the bearing bush, the sleeve, and the journal surface. In addition, the abnormally high temperature softened the induction-hardening case on the journal surface and decreased the fatigue strength. Fatigue crack initiation occurred at the root fillet of the groove because of the stress concentration in that area.     

Fracture and Wear Failure of a Locomotive Turbocharger-Bearing Sleeve

A failure investigation was conducted on a locomotive turbocharger-bearing sleeve. The failed bearing sleeve is made of 38CrMoAl steel and the external and internal surfaces are nitrided. The fracture took place at the transition fillet between the cylinder and the plate of the bearing sleeve. Multiple origin fatigue fracture was the dominant fracture mechanism. Serious wear took place on the external surface of the bearing sleeve. Metallurgical examination indicated that the depth of the nitrided layer on the surfaces of the bearing sleeve was generally below the acceptable limit set by the manufacturer. The thin nitrided layer on the external surface of cylinder was rapidly worn from the cylinder in service and the soft underlying matrix was exposed. At this point, the wear on the cylinder surface increased intensely and ultimately lead to increased friction between the external surface of the bearing sleeve and the bearing bush. Fatigue crack initiation occurred at the root fillet between the cylinder and the plate because of stress concentration in that area and the increased frictional forces. In addition, the insufficient nitrided layer depth in the fillet region facilitated propagation of fatigue crack. Appropriate nitriding process should be conducted on the bearing sleeve to obtain a sufficient hardening depth thus inhibiting surface wear and preventing fillet fatigue failure.     

HP410型空压机轴振动超标故障分析及处理

介绍HP410型空压机运行时轴振动超标的故障,原因是二级叶轮被从中间冷却器来的压缩空气中夹带的水分冲击而腐蚀以及轴瓦间隙超标,更换二级叶轮及改进轴瓦结构形式后,改善了轴瓦的承载力并有效减小了空压机的轴振动值。     

Design of the hybrid composite journal bearing assembled by interference fit

In this work, a hybrid composite journal bearing (HCJB) composed of carbon/phenolic laminated composite bush and steel housing was designed for marine vessels because the composite journal bearing reduces the possibility of the seizure problem between the journal and bearing. The two components of bearing were assembled by interference fit joining method and a series of durability tests were conducted using the laboratory bench with the lubricants of SAE 30 oil, water, and sea water. That the HCJB was found reliable under the interference fitting loads and environmental temperature change.     

Influence of cryogenic treatment on load bearing ability of interference fitted assemblies

The objective of this paper is to study the influence of cryogenic treatment of pin on load bearing ability of interference fitted assemblies. En8 steel was used to prepare the pin and bush. The pins were soaked in liquid nitrogen (cryogenic temperature) and ice for different time periods. The bushes were heated and then assembled without applying the external pressure. The assemblies were tested for their strength. A comparative study on results of experimental and Lame’s approach has been carried out. The results reveal that assemblies with cryogenically treated pin exhibits higher load bearing ability. The degree of increase in load bearing ability with increase in soaking time at cryogenic temperature is small. The variation in load bearing ability obtained through experimental investigation is in agreement with that of Lame’s approach.     

计入应力偶效应和空化效应的滑动轴承热流体动力润滑数值研究

基于应力偶理论和Elrod空化算法建立了滑动轴承热流体动力润滑数学模型，数值求解了应力偶流体的Reynolds方程、油膜能量方程及轴瓦热传导方程，考察了应力偶效应对滑动轴承热流体动力润滑性能产生的影响。结果表明：应力偶流体明显地提高了油膜压力，降低了轴承摩擦系数，同时也使端泄流量和轴承的温度场有所改变。     

A model for the evaluation of wear and durability of a plain bearing with small out-of-roundness

A computational model is developed for the evaluation of the kinetics of wear and durability of plain bearings taking into account the presence of small out-of-roundness of the contours of their components operating in contact. By using the developed cumulative model, we study the schemes of plain bearings with different lobing of the shaft and the bush. It is shown that the degree of wear of the bush of a bearing increases in the case of lobing of one or both elements. At the same time, the degree of the wear of the shaft decreases. More complex types of lobing of the contours clearly lead to strong changes in the degree of wear.     

An analogy between radially-loaded rubber bush mountings and axially-loaded bonded rubber blocks

The validity of the widely-quoted experimental data for the reduced radial stiffness of a cylindrical rubber bush mounting of finite length is discussed by proposing an analogy between such a bush and two tandem cylindrical rubber blocks of circular cross-section which are axially loaded. Previously-derived expressions for the radial stiffness of a finite-length cylindrical bush and the apparent Young’s modulus of an axially-loaded bonded rubber block of circular cross-section are exploited. This leads to an adaptation of the data that incorporates the possible failure of the bushes due to internal rupture. The analytically-derived values of this stiffness are demonstrated to have improved agreement with these appropriately modified data. Representative numerical results are presented for a range of bushes in tabular and graphical forms.