摘　　要

轮对轴承是旋转机械中应用最广泛的一种通用部件，也是机械设备中的易损零件，许多机械的故障都与轮对轴承的状态有关。据统计，在使用轮对轴承的旋转机械中，大约30％的机械故障是由于轮对轴承的损坏造成的。可见，轮对轴承的好坏对机械系统工作状况的影响极大。由于设计不当和安装工艺不好或轴承的使用条件不佳，或突发载荷的影响，使轴承运转一段时间后会产生各种各样的缺陷，并且在继续运行中进一步扩大，使轴承运行状态发生变化。因此，轮对轴承的故障诊断一直是研究的热点。

本文首先从理论上分析了轮对轴承的失效形式、振动机理、振动类型、及发生故障的原因、振动频率；然后在理论基础上提出了轮对轴承的时域、频域的诊断方法；最后搭建了基于Matlab的轮对轴承故障诊断系统，并通过Matlab仿真轴承故障信号，在软件中进行信号分析和处理，验证各种诊断方法的优劣和轮对轴承的故障特征。

本论文按照预定的要求完成了设计任务，研究了轮对轴承的故障诊断方法，完成了故障诊断系统的设计，通过仿真验证了轮对轴承的故障诊断方法。

关键词：轮对轴承；故障诊断；时域分析；频域分析；Matlab

Abstract

Rolling element bearing is one of the most widely used general part of rotating machinery,and one of the most easily damaged parts of mechanical equipment. A lot of mechanical failure is relevant to the state of rolling element bearings. It is estimated that about 30 percent of mechanical failure is caused by its fault in the rotating machine with rolling element bearings. It is obvious that the quality of rolling element bearings has a great impact on the working condition of electromechanical systems. Because of wrong design, poor working condition or a jump heavy load, bearing will be damaged and worse during the running time. So at present, the fault diagnosis of rolling element bearings is a research hotspot.

Firstly, the failure forms, the vibration mechanism, vibration type, and the  failure cause, vibration frequency of bearing are analyzed in theory.Secondly, based on the theory put forward the time domain, frequency domain diagnostic methods.Finally, the software for the fault diagnosis system of the rolling bearings is designed by Matlab,along with the simulation of bearing fault signals by Matlab.To analysis and processing the signal in software. Verify the merits of various diagnostic methods and characteristics of rolling bearing faults.

The paper successfully completed the design task and the result meets the expectation. We researched the fault diagnosis methods and completed the fault diagnosis system design and simulation shows the fault diagnosis methods of rolling element bearings.

KeyWords：rolling element bearings,fault diagnosis,time-domain analysis,

frequency-domain analysis,Matlab