Failure analysis of aisi 304 stainless steel shaft. Pdf failure analysis of aisi 304 stainless steel shaft. Failure analysis is a technique where facts are gathered through investigations and testing and analyzed to determine the root cause of a product failure. This project is to study about the failure that happens to the drive shaft. Stress analysis, failure analysis, optimize, tensile strength.
Failure analysis failure analysis is the process of collecting and analyzing data to determine the cause of a failure. Failure analysis of conveyor pulley shaft sciencedirect. This article describes in detail the approach and root cause for failure of pinion shafts used in bowl mills of thermal power plants. By considering the drive system forces and torque acting on the output shaft are determine using which the stresses occurring. When disassembling subassemblies and parts, do not clean the parts immediately since cleaning may destroy some of the evidence. Obtaining background information such as serviceoperating conditions, manufacturing history, discussions with the enduser andor eye witness to the failure, 2. This paper describes the failure analysis expertise of the combine harvester axle shaft, made of heat treated crmo steel. See discussions, stats, and author profiles for this publication at. Check the shaft for damage, bent tubing, or missing balance weights.
Top failure mode is highspeed shaft hss or intermediatespeed shaft ims bearing axial cracks damage. Failure analysis introduction having a wheel shaft which is directly driven from a power source in this case, the engine of a motorcycle using a timing belt transmission is a common means for driving small, relatively low cost vehicles. So it is important to identify the major problem of failure to avoid the future failure of that part. Stress analysis assuming a solid shaft with round cross section, appropriate geometry terms can be introduced for c, i, and j resulting in the fluctuating stresses duedueobed gadoso as to bending and torsion as combining these stresses in accordance with the distortion energy failure. Analysis and failure improvement of shaft of gear motor in. This guide will teach you to design, test, install, and maintain your highperformance turbo system. Root cause ac motor failure analysis 1439 table vii common steels and their characteristics table viii causes of shaft failures adapted from 18 a significant number of failures can be diagnosed with a fundamental knowledge of motor shaft failure causes and visual in. Design, failure analysis and optimization of a propeller. The mechanical design analyses establish the cause of. Sometimes operating conditions change to become quite different from the specific conditions for which the seal was intended. The common failure modes of gear shafts were failed to be in decreasing order of frequency, as follows. Shaft failure leads to heavy loss due to stoppage and repairing cost associate with the breakdown. A service water pump in a nuclear reactor failed when its shaft gave way. This paper deals with the failure analysis and redesign of shaft of overhead crane having capacity 25 tonne.
A reexamination of failure analysis and root cause determination m. Pdf this paper reports the results of failure analysis of a two high gearbox shaft of a gearbox in a hot steel rolling mill in thailand which fail. For failure analysis, it is important to accurately determine the time a fracture occurs, because the possible. Experimental analysis of failure of drive shafts ijiet. Failure analysis of gearbox shafts page 1 of 11 failure analysis of gearbox shafts 1. Failure analysis of water pump shaft article pdf available in journal of failure analysis and prevention 102. Dec 27, 2016 shaft failures do not happen everyday, but when they do, it can be a challenge to determine the cause of failure. Gibbon matco associates po box 15580 pittsburgh, pennsylvania 15244 4127881263 december 2004 failure analysis is a complex process applied to all different types of materials. Standard procedures for failure analysis were employed in this investigation. Shaft is subjected to bending and torsional stress.
Shaft failures do not happen everyday, but when they do, it can be a challenge to determine the cause of failure. Fatigue failure also known as failure due to reversed bending fatigue with rotation is the most common cause of pump shaft fracturesfailures. Spiral failure caused by conditions which allow some parts of the ring to slide and others to roll causing. Fatigue failure analysis of a centrifugal pump shaft intechopen. Failure analysis of a shaft used in a bridge crane has been carried out. If the shaft was under any flex then it will have work hardened at the area of breakage.
Infiltration of corrosive gases, liquids including water or solids can result in corrosive chemical reactions on bearing, gear and seal contact surfaces that can cause premature failure or abnormally high wear rates. Just as failure analysis is a proven discipline for identifying the physical roots of failures, rootcause analysis rca techniques are effective in exploring some of the other contributors to failures, such as the human and latent root causes. Gearbox typical failure modes, detection, and mitigation methods presentation, nrel national renewable energy laboratory. The finite element stress analysis concluded that stress levels developed in the shaft at the failure location are too low to lead to fatigue failure when considered in isolation. The parting of the shaft was determined to have been caused by an impact failure mechanism, with the origin at the incipient cracks in the weld metal. The shafts purpose is to transmit the rotational motion and power torque from the driver to the pump shaft components, mainly the impellers. Causes of transmission failures parts analysis process spur gears 90 roller bearings 93 main shaft washer. Pdf failure analysis and redesign of shaft of overhead crane. Torsional failure modes example angle of twist in elastic range statically indeterminate shafts example. The analysis of this failure was much more detailed, but provided here is a summary. Failure and the failure analysis experience indicates that despite adhering to the available design procedures, premature failure of the rotor shaft during operation of the centrifugal pump is. The procedures are demonstrated in performing failure analysis of a centrifugal pump shaft. Failures of the front pump are, in fact, limited to just a few specific modes such as overheating, overpressurization, shaft failures, contamination and cavitation. First, identify the failure cause and condition of the drive shaft.
Fatigue failure analysis of a centrifugal pump shaft. Understanding factors that cause shaft failures pumps. This blog is a continuation from the previous article from becht engineering, shaft fatigue failures part i. Oversize shaft, rough surface finish, excessive fluid temperature causing elastomer to stick to the shaft, contaminants.
The best way of using the handbook and estimating the failure rate of a mechanical seal is use of the failure mode, effects and criticality analysis fmeca. In carrier failure analysis, it may be necessary to disassemble the unit. Tests performed on samples of the shaft showed that the material has a fatigue limit at a stress range in excess of 300 mpa. The shaft fractured in the keyway with evidence of fatigue. Too often, when a failed component is replaced without determining its cause, there will be a recurring failure.
Both failures are believed the result of operating conditions acting on toolmarks on the keyway. A shaft is a rotating member usually of circular cross. Failure analysis is simply allowing the seal to tell why it did not perform as expected. Apply a static equilibrium analysis on the two shafts to. In order to do this, detailed records of each failure should be maintained. Among the firms capabilities are vibration monitoring, mechanical failure anlaysis. After that we can make an analysis and we try to solve the problem.
Heres a technical explanation of what happens when the shaft bends or breaks. Root cause ac motor failure analysis with a focus on shaft. Any static overload or severe impact can cause brinelling. Pdf failure analysis of a two high gearbox shaft researchgate. The chemical, microstructural, and fractographic analyses provide information on the material science aspects of the failure. Problems at the faces carbons, ceramic, silicon and tungsten carbide faces. Cause, analysis and prevention of motor shaft failures ieee xplore. Advances in automobile andal et al adv automob eng. The attraction of a rotating wheel shaft is that it can be made. Failure analysis of gas blower shaft of a blast furnace reliability based analysis of wedge failure in a vertical shaft a step towards safety. You are likely correct in that it looks like it was too brittle, because the cyclic work action will have work hardened it until it got too hard to flex without cracking. This paper describes the failure analysis of rear axle shaft used in an automobile. The axle shaft was received as fractured after three years of operation. Problems at the faces carbons, ceramic, silicon and tungsten carbide faces wear heat hangup.
Table 201 shaft failure modes failure mode failure cause failure. The first event was most probably a transverse fatigue failure, and the second failure was the peeling failure. Seal was started on shaft, then removed and reinstalled. Pdf failure analysis and redesign of shaft of overhead. Failure analysis failure analysis is the process of determining the original cause of a component failure in order to keep it from happening again. The machinery engineer must therefore be prepared to learn from each seal failure and use that information to improve future designs and applications so that seal life is improved. Machinery failure analysis and troubleshooting, fred geitner and heinz bloch. Introduction to failures failure of the mechanical shaft seal is the most common cause of pump downtime. However, the information is not sufficient to do indepth bearing failure analysis and does not compensate for experience neces sary in this domain. Failure of a service water pump shaft handbook of case. Section 3 contains descriptions of failure types that affect parts, as well as parts analysis terminology thats used in the field to describe conditions that cause components to fail. All books are in clear copy here, and all files are secure so dont worry about it.
The fracture originated in the threaded portion of the sleeve nut on the driveend side of the shaft. Results of the failure analysis showed that the cracking initiated at the thread root as a result of corrosion fatigue. For most machine shafts, however, analysis should be. Additionally, the coarsened heataffected zones were found to be hydrogen embrittled. With the knowledge presented in this publication, it is pos sible to assess simple failure situations and start the right analysis. Due to the difficulty to find adequate areas for indoor parking. When performing a thorough shaft failure analysis, our experts and engineers take into consideration the shafts postfailure condition, operating environment, metallurgical factors, equipment history, recent operational repairs, product design and inservice handling. This analysis clearly indicated that ceasing of the movement of the bowl mill segment all of a sudden due to hard, rocky lumps was the main cause for failure. Failure analysis in study of any failure, the analyst must consider a broad spectrum of. This paper presents the comparison of the different methodology used, their application and limitation by. Failure analysis of centrifugal pump shaft free download as word doc.
A rotating bending fatigue failure from a motor shaft. W hether related to motors, pumps or any other types of industrial machinery, shaft failure analysis is frequently misunderstood, often being perceived as difficult and expensive. The failure consisted of a transverse fracture through the shaft diameter near the keyway center, coupled with a peeling failure in the keyway that progressed around and along the shaft. The shaft seal is exposed to widely varying operating conditions. The latter was probably driven by the torsional load. When performing a thorough shaft failure analysis, our experts and engineers take into consideration the shaft s post failure condition, operating environment, metallurgical factors, equipment history, recent operational repairs, product design and inservice handling. This process is a function of time, temperature, speed, load and environment. Hydraulic gear pump and motor failure analysis and repair. Section 1 is an overview of parts analysis, and section 2 provides guidelines for using an investigative approach during the analysis process.
A mechanical seal will normally be a component part of a pump, compressor or other system component at a higher indenture level. Before getting into the calculation methods, first a quick refresher on high. Vibratory loads, or system dynamic loads depend on the interrelation of the components in the entire system with one another and torquemeter readings or a study of the system is required to assess instantaneous loads. Failure analysis of machine shafts efficient plant. Root cause analysis of bowlmill pinion shaft failures. Failure analysis of a crane gear shaft pdf free download. Then do the hardness test to know how hard the material that use in drive shaft. Root cause failure analysis understanding mechanical. Advances in automobile andal et al adv automob eng 10. Apply a static equilibrium analysis on the two shafts to find a relationship.
The shaft breakage occurred due to dynamic, alternating. A reexamination of failure analysis and root cause. By tracing the progression marks backward, we can see the failure started at the corner of the keyway. In most cases, damage to the front pump is a result of a failure and not the true cause of the failure. The primary cause of the failure was the use of an unspecified material.
Root cause ac motor failure analysis 1439 table vii common steels and their characteristics table viii causes of shaft failures adapted from 18 a significant number of failures can be diagnosed with a fundamental knowledge of motor shaft failure causes and visual inspection. The overall subject of this paper is the frequent failure analysis of output shaft of gear motor used for cold rolling mill to drive the payoff fourhi horizontally inserted. Check the slip spline for excessive radial movement. Pdf fatigue failure analysis of a centrifugal pump shaft. Abstract the various methodology used for failure analysis of the shaft used in. The objective of this paper is to study various shafts failure analysis and select the best method to find out the root cause failure of heavy nip roller shaft used in. International journal of engineering research and general. Gearbox typical failure modes, detection and mitigation. Gearbox typical failure modes, detection and mitigation methods. There is problem of failure of the shaft in gear box which is mounted on the crane. What went wrong and how to fix it includes instructional photos, checklists, and stepbystep instructions. When tearing down the drive axle, do it in the recomthe appropriate service manual to perform the repairs. Failure analysis component failures can result from improper maintenance, installation, or assembly procedures.
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