管窥机械维修过程中轴承的维修要点

轴承的运行状态对机械设备的性能会造成最直接的影响,轴承是机械设备当中的关键性部件,也是在高强度工作下易出故障的部位。因此,在对轴承进行检修时,要了解轴承经常出现的故障及原因,对其运行状态、原理、构造,以及日常保养进行分析,对明确轴承维修的要点,开展有效的维修工作。     

简论机械维修过程中的轴承维修

为了能够确保机械设备的正常运行,尽可能地延长机械设备的使用寿命,就需要加强对机械设备的日常维护和维修。轴承维修在整个机械设备维修的过程中占有非常重要地位,轴承质量会对整个机械设备的使用寿命造成影响,同时也能对机械设备的维修效果进行衡量。鉴于此,笔者现简要地分析轴承安装以及拆卸方法,然后探讨轴承维修中的故障处理及注意事项。     

浅谈机械维修过程中如何对轴承进行维修

在社会上许多工程或者制造行业都需要相应的机械设备进行工作,这就导致在机械设备的长时间的使用过程中就容易发生故障,使得机械设备的正常运作受到一定的阻碍。因此这就需要对相应的机械设备出现的故障进行合理的维修,从一定的角度上使得机械设备能够达到良好时的使用状态。而且在机械设备的使用过程中,关键的地方在于轴承的使用,而且在很大程度上来说轴承的维修是属于整个机械设备维修过程中最为复杂的一项,因此轴承的维修对整个机械设备的维修来说起到非常重要的作用。     

汽轮机轴承典型故障的分析与对策

文章针对电厂汽轮机轴承故障这一电厂主机较为常见的一种典型故障,从汽轮机轴承结构特点、发生故障的原因、预防的措施等方面进行了较为详尽地阐述,对分析汽轮机轴承故障,预防轴承事故的发生具有较好的参考价值。     

航空发动机的轴承故障动力特征指纹提取方法研究

航空发动机主轴轴承是航空发动机中的关键部件,其使用条件苛刻,长时间工作在高速、高温的恶劣环境下,因而它是发动机最容易损伤的零件之一。主轴轴承损伤会导致发动机故障,严重威胁飞机的安全平稳飞行甚至造成更大的安全事故。故而,针对航空发动机主轴轴承进行故障评定方法研究,对于及时发现航空发动机主轴轴承缺陷,确保航空器的安全飞行具有重大意义。对航空发动机主轴轴承的状态监测、评定及诊断,其关键、难点在于如何从轴承振动信号中提取出轴承的动力特征指纹信息。在某种程度上,动力特征指纹提取可以说是当前航空发动机主轴轴承故障评定与诊断研究中的瓶颈问题。     

轴承损伤的分类与分析

了解轴承故障的根源不仅能保证轴承的可靠运转,而且有可能做到提前预测和发现故障,并利用生产间隙排除故障,避免昂贵的停机,减少维修成本。本文通过对轴承故障进行分类,有助于了解故障发生原因,找到问题的根源和解决方法。     

电厂设备轴承组件维修探讨

在现代电厂设备维修养护工作中,轴承组件的维修是维修养护部门的重要工作内容.由于电厂设备的特殊性使得电厂轴承组件较多,而且轴承组件对电厂设备运行有着重要的影响,一旦轴承组件出现故障将导致机组的停运,严重时还将导致更加严重事故的发生.针对电厂设备轴承组件维修的重要性,现代电厂应引入预防性养护理论,以预防性养护理论的引用减少电厂设备轴承组件故障,提高电厂设备的运行效率及运行安全性.本文就电厂设备轴承组件的维修进行了简要论述.     

试析电力通信网中通信电源故障与维护策略

通信电源故障是电力通信网中断的主要原因之一。要减少通信电源故障对电力通信网造成的不良影响,一方面要提高通信电源故障的维护效率,加强对机房的监控力度,及时发现通信电源故障并进行维修,恢复电力通信网的运行;另一方面要加强日常维护工作管理,在故障发生前及时排除设备隐患,提高设备的性能,尽可能减少通信电源发生故障的情况。     

CET风机驱动端轴承频繁故障原因分析

国内某核电机组自商运以来,CET风机出现若干次故障,在机组大修期间对CET101/201ZV进行预防性维修时发现,风机驱动端轴承靠近风机侧滚子及轴承内圈有不同程度的损伤,通过力学校验计算,发现风机接口载荷与设计值严重不符,风机接口载荷严重超标,造成风机轴承频繁损坏。     

浆板机压力筛顶部电机轴承失效分析

轴承损坏是电动机常见的设备故障,本文从故障轴承表面磨损情况和采集的振动数据两方面进行原因分析,并从维护维修角度提出预防措施。     

重载铁路货车轴承突发性损伤类故障检测

重载的铁路货车滚动轴承极易出现损伤类故障,因故障的突发性使得振动信号具有非线性、非平稳的特性,且振动信号极易受非检测部位振动的干扰,而使得有效信号不易被提取,传统的基于傅里叶变换的检测方法无法有效将非平稳的振动信号中的干扰去除,造成最终的检测准确率不高的问题。为了提高检测准确率,提出基于小波包的检测方法,首先针对振动信号的非平稳特性采用小波滤波有效去除其中的干扰,然后通过最小二乘支持向量机提取出非平稳振动信号中的故障特征信号并完成故障检测。实验表明,这种方法能够有效去除振动信号中的干扰,并准确检测重载铁路货车上的滚动轴承损伤故障。     

基于核Fisher判别分析的滚动轴承故障诊断方法

本文提出了基于核Fisher判别分析的滚动轴承故障诊断方法。该方法利用非线性核函数将数据从原始空间映射到高维特征空间,在高维特征空间中利用Fisher判别分析方法提取最优的Fisher特征矢量和判别矢量来实现滚动轴承的状态监控与故障诊断。试验结果表明,核Fisher判别分析方法能很好地识别滚动轴承的故障模式。     

Unsupervised cross-domain rolling bearing fault diagnosis based on time-frequency information fusion

In recent years, data-driven methods have been widely used in rolling bearing fault diagnosis with great success, which mainly relies on the same data distribution and massive labeled data. However, bearing equipment is in normal working state for most of the time and operates under variable operating conditions. This makes it difficult to obtain bearing data labels, and the distribution of the collected samples varies widely. To address these problems, an unsupervised cross-domain fault diagnosis method based on time-frequency information fusion is proposed in this paper. Firstly, wavelet packet decomposition and reconstruction are carried out on the bearing vibration signal, and the energy eigenvectors of each sub-band are extracted to obtain a 2-D time-frequency map of fault features. Secondly, an unsupervised cross-domain fault diagnosis model is constructed, the improved maximum mean discrepancy algorithm is used as the measurement standard, and the joint distribution distance is calculated with the help of pseudo-labels to reduce data distribution differences. Finally, the model is applied to the motor bearing for comparison and verification. The results demonstrate its high diagnosis accuracy and strong robustness.     

基于主元分析的传感器故障检测研究

基于主元分析(PCA)的故障诊断方法是故障诊断领域一个重要研究分支。本文首先介绍了主元分析的理论,然后深入研究了基于主元分析方法的传感器故障检测问题。该方法能够在对测量参数相关性分析的基础上,将传感器测量值所组成的测量空间分解为主元和残差两个子空间,通过传感器实际测量数据与正常数据矩阵在残差子空间投影的比较,对传感器的故障进行检测。最后进行具体仿真,仿真结果表明主元分析法对传感器具有很好的故障检测能力。     

汽轮发电机组振动故障分析及处理

C25-8.83/0.981是一台抽汽供热式汽轮发电机组.该机组在启动调试过程中,发现其存在四号轴承轴向振动超标故障、发电机转子热不平衡故障和汽轮机动静碰磨故障等问题.本文通过启动运行过程中对机组参数监控及轴系振动的监测,经过对现象及相关数据的分析,并在停机过程中多次进行调整.最终确定四号轴承轴向振动超标的主要原因是由于该轴承球面与球面座定位销错位,引起定位销卡涩,从而使激振力投影点与轴承几何中心不重合,致使四号轴承轴向振动过大.而发电机转子热不平衡和汽轮机动静碰磨的故障现象是在机组并网带负荷运行过程中四号轴承和二号轴承相继振动过大.经分析判断,主要是由于发电机转子在运行过程中发生了热弯曲,从而造成发电子转子热不平衡,产生较大的轴向振动,进而影响到汽轮机转子并致使动静碰磨造成二号轴承振动过大.最终通过现场动平衡,加配重,才使这一问题得到较好的解决.     

6L2K活塞式压缩机滑动轴承失效分析

根据滑动轴承的工作原理、正常工作条件,分析了活塞式压缩机滑动轴承巴氏合金轴瓦常见的失效形式。确保滑动轴承的制造质量、安装质量、润滑油质量;加强管理、精心操作,均可有效提高滑动轴承的使用寿命。     

A quantitative causal diagram based optimal sensor allocation strategy considering the propagation of fault risk

Optimal sensor allocation can substantially reduce the life cycle maintenance costs of engineering systems. Considerable effort has been exerted to model the causal relationship between sensors and faults, but without considering the propagation of fault risk. In this paper, a grey relational analysis (GRA) based quantitative causal diagram (QCD) sensor allocation strategy is proposed that can take account of the influence of the propagation of fault risk. QCD is used to describe both the fault-sensor causal relationship and the fault-to-fault causal relationship. A data-driven-based GRA is applied in QCD to calculate the coefficients of the propagation of fault risk. To achieve an accurate relationship between faults and sensors, an improved quantitative analytic hierarchy process is proposed to calculate the coefficients between faults and sensors that is defined as sensor detectability in this paper. An optimal sensor allocation strategy is then developed using an improved particle swarm optimization (IPSO) algorithm under the constraint on sensor detectability to minimize fault unobservability and total cost. The proposed strategy is demonstrated by a case study on a single-phase inverter system. Compared with two other sensor allocation strategies, the results show that the proposed strategy can obtain the lowest fault unobservability of per unit cost (?0.242) for sensor allocation under the propagation of fault risk.     

Data-driven fault diagnosis for an automobile suspension system by using a clustering based method

This paper concerns the issues of fault diagnosis and monitoring for an automobile suspension system where only accelerator sensors in the four corners of the car body are available. A clustering based method is proposed to detect the fault happened in the spring, and the Fisher discriminant analysis is applied to isolate the root factor for the fault. Different from most of the existing approaches, the pure data-driven characteristic enables this method to serve as an on-line fault diagnosis and monitoring tool without suspension model or fault features known as a prior. Moreover, this method can classify different reductions in the spring coefficient into one fault rather than different faults. The effectiveness of the proposed method is finally illustrated on an automobile suspension benchmark.     

Fault detection for a class of nonlinear networked control systems with Markov sensors assignment and random transmission delays

The paper investigates the fault detection problem for a class of nonlinear networked control systems with both communication constraints and random transmission delays. The access status of the sensors is governed by a stochastic event, which is modeled as a Markov chain taking matrix values in a certain set. The main task of this paper is to design a mode-dependent fault detection filter, such that for Markov sensors assignment, random network-induced delays and the unknown input signal, the error between the fault and the residual signal is minimized. And the resulting fault detection dynamics is formulated as an _H∞$H_{\infty }$ filtering problem of a Markov jump system. The linear matrix inequality-based sufficient conditions for the existence of the fault detection filter are obtained. Finally, two examples are given to show the effectiveness of the developed method.     

热轧精轧机活套液压控制及故障分析

现在对热轧带钢产品厚度、宽度等质量指标的重视。精轧机活套是热轧线的重要设备,能实现机架间带钢的稳定轧制,以便提高产品产量和质量。本文是针对其的液压控制系统及常见故障的分析和处理。