某轮主机连杆大端轴承损坏原因分析

针对四冲程船舶主机由于管理和润滑等原因易出现连杆轴承损坏的现状,通过对某轮四冲程船舶主机连杆大端轴承烧损事故的案例分析并结合船舶轮机管理的要点,采用案例分析与原因推断相结合的方法,推断出了四冲程船舶主机连杆轴承损坏的原因并给出了预防对策,尽可能的避免了四冲程船舶主机连杆大端轴承烧损事故的发生。     

Sulzer 16ZAV40S柴油机轴瓦咬合事故原因分析

就Sulzer 16ZAV40S柴油机连杆发生大端轴瓦咬合事故，进行分析与探讨，根据现场的记录和原始资料，排除了一些不会导致轴瓦产生咬合的因素，认为连杆大端轴承座孔变形，轴承间隙过大以及连杆大端轴承紧固螺栓松驰与此次事故有密切关系。     

关于TL轮主机连杆大端轴承烧损的处理对策

TL轮从1999年起,发生多起主机连杆大端轴承在使用期内的烧损事故,并且大多发生在主机启动运行1～2小时内。最近一次是2002年3月17日,船在长江口起锚进港,主机运行不到0．5小时,曲拐箱油雾浓度报警自动停车,事后检查发现,主机NO．7连杆大端轴承烧损,引起曲柄销粘着磨损。这一连串的事故既影响了船舶的安全生产,同时也给轮机管理人员带来了很大的烦恼。     

定速柴油主机连杆大端轴瓦抱轴事故的思考

1连杆大端轴瓦抱轴事故最近几年,某公司多艘船龄在10年以上的不同品牌的500r/min定速四冲程柴油主机,都发生过类似的连杆大端轴承轴瓦抱轴事故。这些事故均发生在:船龄较大(10年以上);变距桨定速主机加速到额定转速后不久。事故损失巨大。例如某轮,变距桨定速主机启动,达到额定转速后不久,曲拐箱油雾浓度报警装置报警,停车检查,见某缸连杆大端轴承轴瓦抱轴,只能卸货进··     

MAK主机轴瓦见症分析及管理

N轮左、右主机，型号为MAK9M552AK四冲程柴油机，每台机功率5000kW，额定转速480r／min，可调螺距。笔者有幸在此船工作了一段时间。上船之前，接连两个航次右主机No．3，No．9缸连杆大端轴瓦烧熔，造成曲轴损伤，连杆大端轴承座孔变形，不得不磨削曲柄肖，更换连杆大端轴承座，换用加厚轴瓦。查看以前记录，左主机No．5、No．9缸以前也发生同样的故障，造成曲柄肖磨削。对于船用主机来说，曲轴是柴油机中最重要昂贵的部件，轴瓦是至关重要的部件之一。轴承和轴颈一旦发生损坏，靠船员自身力量一般难以修复，对海上航行船舶的安全构成严重威胁。     

低速机连杆大端轴瓦安装挤压点分析

某新型低速柴油机连杆在样件加工完成后,先对连杆大端轴承孔进行尺寸测量,然后通过轴瓦挤压点实验,得到连杆大端挤压点值。采用有限元方法计算轴瓦挤压点,仿真计算结果与实验结果相符,仿真方法对实验进行了很好的验证和补充作用。通过在仿真模型中改变连杆大端连接螺栓位置,分析了连接螺栓位置对轴瓦挤压点影响规律。     

滑油脏污对柴油机伤害案例的技术分析

本文以某大马力远洋拖轮的连杆轴承并曲拐销烧损的案例,进行了系统性地分析,得出该主机的滑油脏污以及滑油中存在的细微颗粒物,是造成该轴承及轴颈烧损的最大可能原因。同时指出,该机型的主轴瓦上瓦及连杆瓦上瓦的多孔设计,存在着积聚滑油中悬浮细微颗粒物的风险。对今后类似柴油机的修理以及轴瓦生产厂家有较大的技术参考价值。     

B＆W6S型主机十字头侧向导板固定螺丝断裂分析

本文抓住某轮主机十字头导板固定螺丝断裂、连杆大端轴承脱铅现象，通过对组成部件及原材料构成，透彻地分析了引发故障的原委，并对日常管理要点提出了自己的见解。     

多列式柴油机连杆轴瓦的应力分析

一、前言 42—160高速柴油机是船用的主机,气缸布置成七列星型,每列六缸,共有气缸42个。连杆采用主、副连杆结构,主连杆轴瓦为翻边结构,主连杆大端及轴瓦受力情况极为复杂.     

G32柴油机连杆轴瓦瓦面局部半干摩擦产生的原因与消除

连杆大端轴瓦是柴油机中工作环境最为恶劣的运动配合件之一。连杆轴瓦工作时不仅受到气缸内气体爆发压力和活塞连杆部件往复惯性力的交变和冲击负荷的作用,而且由于轴瓦表面与曲柄销之间的高相对运动速度,使轴瓦很容易发热和磨损。而不合理的轴瓦结构设计容易使其瓦面局部产生半干摩擦,从而造成更强烈的磨损。本文对柴油机连杆大端轴瓦瓦面局部半干摩擦产生的原因进行了分析,并提出改进措施,有效的消除了连杆大端轴瓦瓦面局部半干摩擦的产生。     

Experimental uncertainty of a physical model of a tanker moored to a terminal in a port

This paper presents the uncertainty modelling of experimental results for a physical model of a tanker moored to a terminal inside a port. The physical model was built for an oil terminal at the port of Leixões in Portugal. The model incorporates the new modified port layout, as well as a future 300 m extension of the port outer north breakwater to enhance operational conditions. The physical model tests were performed on a scale of 1:80 in the Portuguese Civil Engineering Laboratory (LNEC). A generic mooring system of four mooring lines and two fenders is simulated using a nonlinear spring system. Decay tests are carried out to evaluate the natural periods of the moored model. Then, tests are carried out for the moored model in waves. The major aim of the experimental study is to obtain novel results for the wave elevation and direction at various locations inside the port, the ship motions at six degrees of freedom, and loads on mooring lines and fenders including the modified port layout. As the physical model measurements are subjected to different types of uncertainties, a systematic uncertainty analysis is carried out here, following ITTC guidelines and recommendations, to quantify all possible sources of uncertainties. The results are discussed, and several conclusions are reached. Based on the experimental results, the presented physical model study may replicate the results for waves and motions with uncertainties less than 9% of the significant amplitudes. The assessment of the applied nonlinear spring model reveals load predictions on the moorings, with uncertainties less than 4% of the maximum mooring loads.     

电缆燃烧性能的实验与仿真研究

在剖析电缆火灾原因的基础上,利用实验方法对阻燃电缆的阻燃性能进行了研究,得出了其在火焰中具有良好的抗火能力;之后利用破坏性实验进一步证明了阻燃电缆的良好抗火性能;然后利用FDS火灾模拟软件对无电缆参与的火灾和有电缆参与的火灾进行了仿真研究,得出了电缆在火灾中是否被引燃主要取决于是否与火焰直接接触的结论;最后,建议人们在电缆防火设计时,重点关注那些容易接触火焰的电缆。     

船用柴油发电机模拟机的设计

柴油发电机是舰船上重要的电源装置,它的性能直接影响到船上的电力系统性能。本文以某船用12相、8极柴油发电机为原型,详细阐述了其模拟机的设计方法。其模拟机的研制,对船上电力系统动态模拟和研究、船用柴油发电机的设计和研制提供了新的手段。     

一种异步电动机故障诊断系统设计

文章分析了传统故障诊断系统的特点，介绍了一种高分辨率谱估计算法-MUSIC算法，并针对该算法特点，提出了一种基于ARM微处理器的异步电动机嵌入式故障诊断系统，重点阐述了系统硬件电路和软件系统的设计，并进行了实验验证。结果表明系统具有硬件电路简单、可操作性较强、实时性可靠等优点。     

Characteristics of a bubble jet near a vertical wall

A numerical model of a coupled bubble jet and wall was built on the assumption of potential flow and calculated by the boundary integral method. A three-dimensional computing program was then developed. Starting with the basic phenomenon of the interaction between a bubble and a wall, the dynamics of bubbles near rigid walls were studied systematically with the program. Calculated results agreed well with experimental results. The relationship between the Bjerknes effect of a wall and characteristic parameters was then studied and the calculated results of various cases were compared and discussed with the Blake criterion based on the Kelvin-impulse theory. Our analyses show that the angle of the jet＇s direction and the pressure on the rigid wall have a close relationship with collapse force and the bubble＇s characteristic parameters. From this, the application range of Blake criterion can be determined. This paper aims to provide a basis for future research on the dynamics of bubbles near a wall.     

Study of a simple sensor for stress history measurements of a structural member using a piezoelectric element

This paper describes a stress sensor using a piezoelectric element which was developed to monitor features of the stress history of a structural member. The sensor is 90 mm long, 60 mm wide, and 25 mm thick. A stress-level meter can turn on and off different colored light-emitting diodes (LED) according to the changes in a stress level. A stress-level cross counter can display the number of cycles which exceeds a specified stress level during a monitoring period. The sensor is bonded onto a structural member using an adhesive agent. In order to see the performance of the prototype sensor, experiments were carried out using a fatigue-testing machine. The sensor was bonded onto a smooth specimen and multiple repeated stresses were applied to that specimen. There were three main findings. (1) The sensor can operate under a stress range from −150 MPa to 150 MPa, and a frequency from 0.05 Hz to 5 Hz. (2) The stress-level meter can turn the lights of the LED on and off accurately under any stress amplitude and frequency. (3) When the stress frequency is 1 Hz or less, the stress-level cross counter can count accurately the number of cycles which exceed the predetermined stress levels. Received: February 25, 2000 / Accepted: April 11, 2000     

一类运输优化问题求解过程分析

通过对运输决策问题中某种基本情况的研究，建立运力有限情况下单个需求点单一物资运输的研究模型，给出求解模型的算法，通过一个算例进行了验证。与目前文献资料中类似研究模型相比较，在决策中考虑运达概率对运输决策的影响是本文模型的一大突出特点。     

高低型双涡流室双缩口燃烧室的排放特性

为优化某船用柴油机的燃烧室的"油-气-室"匹配,降低有害物排放,运用AVL Fire对原型燃烧室改用不同燃烧室进行额定工况模拟.结果表明,高低型双涡流室双缩口燃烧室能在上涡流室形成"飞轮效应",相对于原型燃烧室,不仅能增加功率,而且能降低Nox和SOOT的排放.对高低型双涡流室双缩口燃烧室设置不同的高低涡流室的半径比r/R和喷油夹角进行计算.结果表明:随着r/R从0.3增加到1.3,Nox和SOOT的排放量均先减少后增多;当r/R为0.7时,Nox和SOOT的排放量均最少.当喷油夹角为140°～165°时,随着喷油夹角的增大,Nox的排放量先减少后增加,随后再减少,最后又升高;SOOT排放量先减小后增大,随后再减小.     

某船用大型可拆卸式滚动轴承设计

文章以船用滚动轴承为研究对象,针对该滚动轴承工作中存在的缺点和不足,设计了一种船用可拆卸式滚动轴承,说明了该滚动轴承的工作原理和主要零部件,并利用三维建模软件UG进行了该滚动轴承的零部件及装配体建模,最后进行了滚动轴承装配体的干涉检查,结果表明,所设计的船用大型可拆卸式滚动轴承运行良好。