bearing failures related to motors controlled by variable frequency drives vfds? the cause could be electrical discharge machining (edm).
the occurrence of the motor shaft voltage and bearing current caused by the inverter will aggravate bearing damage and lead to the premature failure of bearings. many types of equipment are being shut down due to bearing currents, such as filters, insulated bearings and grounding brushes. traditional suppression measures cannot eliminate the bearing current and the bearing damage mechanism under the bearing current is not clear. in this paper, the damage caused by the bearing current to bearings is analyzed in detail. the influences of different working conditions on the bearing current and the damage caused are discussed. the source of bearing currents is introduced and the bearing current model under different working conditions is reviewed. an outlook for future studies is proposed, based on the current research status and challenges.
choosing the best remediation method depends on a thorough understanding of the potential current paths in an installation
in modern electric equipment, especially electric vehicles, inverter control systems can lead to complex shaft voltages and bearing currents. within an electric motor, many parts have electrical failure problems, and among which bearings are the most sensitive and vulnerable components. in recent years, electrical failures in bearing have been frequently reported in electric vehicles, and the electrical failure of bearings has become a key issue that restricts the lifetime of all-electric motor-based power systems in a broader sense. the purpose of this review is to provide a comprehensive overview of the bearing premature failure in the mechanical systems exposed in an electrical environment represented by electric vehicles. the electrical environments in which bearing works including the different components and the origins of the shaft voltages and bearing currents, as well as the typical modes of electrical bearing failure including various topographical damages and lubrication failures, have been discussed. the fundamental influence mechanisms of voltage/current on the friction/ lubrication properties have been summarized and analyzed, and corresponding countermeasures have been proposed. finally, a brief introduction to the key technical flaws in the current researches will be made and the future outlook of frontier directions will be discussed.
discover why motor bearings fail prematurely and strategies for optimizing the lifespan and performance of your equipment.
causes of electrical fluting discharge in wind turbine generator bearings and solutions.
shaft currents can have a destructive effect on electric motor bearings. this article, with information from our friends at aegis shaft grounding rings, is intended to inform professionals about these voltages and their effects on bearings in electric motors. because of the high-speed switching frequencies in pwm inverters, variable frequency drives induce shaft currents in …
here are the five warning signs that you should look out for which indicate that it may be time to replace your bearings before failure occurs.
improper lubrication causes 80% of all bearing failure due to insufficient quantity, incorrect type, or improper application.
common causes of motor bearing failure
learn why bearings fail in electric motors. discover common causes, prevention tips, and solutions to extend the life and performance of your electric motors.
research shows that most bearing failure is due to contamination of the oil. what are some of the other common causes? read on to find out!
bearing currents problems
protecting motor bearings and windings is the first step in preventing motor failures. if you want to make a plant manager’s day, just say: “production’s down because a motor failed.” fortunately, such situations can usually be overcome with some relatively simple techniques and straightforward solutions to protect the bearings and stator windings. these two vulnerable…
this article provides information on the reasons for failures in rolling element bearings and the importance of selecting the appropriate lubricants.
electric motor bearing maintenance good maintenance practices yield excellent service from your electric motors. up to 80% of all electric motors, regardless of size, are rebuilt because of bearing…
want to troubleshoot, repair and prevent electric motor failure at your plant? get tips for report writing, root cause analysis, motor management and more!
when bearings fail, production literally grinds to a halt. keeping up with bearing maintenance is key to preventing failure, and it starts with recognizing the signs of potential problems.
the use of methodologies for condition monitoring of rotating machines has been growing to reduce unplanned downtime and to increase the reliability of the industrial processes. the companies must select a correct maintenance strategy to follow the evolution of rotating machines. condition monitoring is the collection of data related to the health status of the machine and it has been widely studied so far. different methodologies have been developed to identify specific behaviors in the condition of induction motors. this paper proposes a methodology for bearing failure detection by using vibrations data, based on the frequency spectrum applied to induction motors. this methodology allows the use of vibration data obtained from motor bearings to establish their condition and therefore determine the type of damage to the bearing. the effectiveness of the proposed methodology is validated using a data set obtained from nasa (national aeronautics and space administration). the results showed that this type of approach is very useful for analyzing bearings and in this way creating maintenance routes based on the condition of the electric machines.
the below video is a 15 minute segment of an hour long presentation given by todd hatfield of heco at the 2017 reliability, process, and maintenance (rpm) symposium. this presentation discusses common preventable causes of electric motor failures. this section of the presentation discusses bearing related failures as bearings account for about 51% of all …
monitoring electric motor bearing condition is paramount to insure reliability. electric motors are an asset that must be managed, and prolonging their life will insure more contribution to …
engine bearings must work in punishing conditions and will soon break down if not maintained. learn about three common causes of engine bearing failure.
bearings are essential components within pumps, we've listed 8 common reasons for bearing failures to look out for. if you're experiencing issues, contact us.
eight vertical circulating water pumps are used to circulate condenser water at the generation station in a nuclear power plant. the pump installation is pictured in figure 1. the motor pump system is arranged vertically with the drive motor above the pump. each pump is driven by a 28-pole, 2500 hp synchronous motor at 271 rpm. the motors sit on a platform that projects out over a large reservoir and each one delivers 275,000 gpm at about 12 psig. the pumps are location below the motors in the reservoir. there are four pumps per generating unit. each unit can run at full capacity drops about 10 percent. three lower motor bearing failures occurred shortly after sudden ambient temperature drops. analysis showed that there was adequate lubrication but the original bearing design was very sensitive to clearance. a finite element analysis of the motor proved that the case would pinch the bearing when cooled from 70 degrees f to 25 degrees f. this reduced the bearing clearance significantly and caused the failures. a new profiled bearing was developed that would provide better rotor support with larger clearances that would be more tolerant of thermal clearance changes. the bearing failure analysis was wide in scope and was conducted by a large team including engineers from the power plant, turbomachinery consultants, repair shops, and bearing manufacturers. many different theories were considered and investigated. this paper examines the investigations of the bearings lubrication with a computational fluid dynamics (cfd) analysis, the motor rotordynamics, the effects of ambient temperature drop, and the manufacture of a new bearing design.
rolling bearings in electric motors have one failure mode which is common to this application: the problem of electric current passing through the bearings causing damage in the contact area between rolling elements and rings. the lubricant film present in the bearing provides separation between rolling elements and raceways, and the lubrication film also creates a small
electric motors are essential to numerous plant operations, no matter the industry, so understanding how and why they fail can help you develop a better maintenance program in your plant.
get the low-down on bearing failure and a handy checklist to help you identify what's up with yours, including signs to look for and proven fixes.
motor bearing care
the 50 failure modes of electric motors electric motors are essential to numerous plants operations, no matter the industry, which is why understanding their 50 failure modes can help you develop a better maintenance program in your plant. electric motors...
vsd’s are the largest single source of bearing failures in the world today. there is a 57% increase in bearing failures worldwide, which is due to the introduction of igbt variable speed drives.
learn more about bearing failure analysis, when it’s needed, and how to perform it to help keep your operations running and profitable.
expert failure analysis of engines, motors, bearings, and mechanical systems by g2mt labs, including metallurgical and corrosion analysis.
bpi offers thorough bearing failure analysis to identify and address the source of bearing problems. supervisory support for bearing installation.