Scratches are relatively shallow marks generated by sliding contact, in the same direction as the sliding. Bearing failure root cause analysis. Damage due to rolling fatigue may occur very early, however. Improper mounting, Shaft deflection, Inaccuracy of the shaft and housing. Improper storage condition, Dew formation in atmosphere. Root Cause Analysis WPIA P4345A Failures-First Bearing failure occurred March 2006-Second failure May 2006 Replace rotor using spare rotor May 2006 ... this does happen in some designs and is not normally a cause of bearing failure. Wear, discolouration and scuffing, caused by slipping on the fitting surfaces. bearing temperature trends, running hours and maintenance history. The purpose of this procedure is to define the steps to do a 4M …. 105 0 obj <> endobj xref 105 32 0000000016 00000 n Extraordinary vibration, impact, moment, Improper or insufficient lubricant, Improper mounting (misalignment), Dents made during mounting. Scuffing on rib face and roller end face. Three major classifications of premature spalling are lubrication, mechanical damage, and material defects. Handling or maintenance regimes. Lack of lubrication in fully loaded bearings will cause prompt and severe failure. Too small internal clearance, Improper or insufficient lubricant, Too much load, Rust. Root cause failure analysis is a process of working backward through a sequence of events or steps that led to functional failure … Install bearings … Smearing on raceway or rolling contact surface. Cause Mapping is a simple and efficient 3-step method which employs the use of an easy to read a visual map. Clean the bearing with anhydrous, neutral light oil or kerosene. Once a failure mode is detected it is important to understand and eliminate the root cause, whether you are correcting an issue early or replacing a failed system. These tests are divided into two categories: non-destructive tests, which keep a product intact; and destructive tests, which require the product to be altered in order to examine cross-sections or thermal behavior. Examples include: using hammers to remove or install bearings, dropping or striking assembled equipment, and a bearing onto a shaft by applying force to the outer ring. The case study is based on the analysis of Failure of Drive Pulley Shafts. In addition to the destruction of the roller separator pictured above, overheating due to high friction will affect all bearing … If you continue to use this site we will assume that you are happy with it. Nicks are those indentations produced directly by rough handling such as hammering. Apply lubricant to the raceway and rolling contact surface when mounting, Improve mounting procedure. Fatigue (Spalling) Spalling is often the result of overloading, an excessive preload, tight inner-ring … This process is often referred to as “Asking the Repetitive Why” or “the Five Whys”. Root Cause Analysis - Learning from Past Failures “Those who cannot remember the past are doomed to repeat it” – George Santayana (1863) Blog Series – Co-Authored by Don ald Rozette and Robert J. Latino . Since fretting on the raceways often appears similar to brinelling, it is sometimes called “false brinelling”. Removing the root cause will ensure a long machine life. HOW HEAVILY WAS IT LOADED? Figure 7. At this point in the root cause failure analysis (RCFA), we have documented financial implications to justify moving forward with the RCFA (we will address additional financial implications as we work through the failure analysis), and compiled a history of the system in question. Behind to determine a root cause analysis difficult are partially melted due to aging, etc rough. 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