• sns01
  • sns02
  • Pinterest
  • sns03
  • linkedin1
English
customers

Apr . 28, 2024 12:12 Back to list

Why bearings fail and what to do about it


Motor bearings are responsible for 51% of all motor failures. (The U.S. Department of Energy puts the number even higher, at 67%.) Find out why bearings are important, what causes bearing failure and get a checklist so you know what to do about it.

Why are bearings important in your motor?

Bearings are critical to the efficient functioning and longevity of an electric motor. Rolling element bearings support and situate the rotor, ensure a small and consistent air gap between the rotor and stator, and transfer load from the shaft to the frame. Without bearings, the motor loses efficiency and power and has increased friction and vibration. Not surprisingly, when bearings fail, there is increased drag, more heat and reduced efficiency.

Causes of bearing failure

  • Improper lubrication
  • Misalignment
  • Incorrect installation and fit
  • Electrical damage
  • Overloading
  • Overheating
  • Contamination

Improper lubrication. According to an article in Reliable Plant, 80% of bearing failures are the result of lubrication failure. That’s a lot of responsibility for a little bit of grease. Lube your bearings properly with the right type of lubricant and keep an eye on motor temperature, as high temps degrade lubricant.

Misalignment. This one can be sneaky, since a motor and load that’s aligned when powered off may be misaligned when normal operation increases the temperature. Watch out for soft foot. (No, soft foot isn’t some weird old timey dance step your grandparents did. It’s improper contact between the machine casing and the base plate, and it’s a major cause of alignment issues.)

Incorrect installation. There are lots of ways to f-up bearing fit, including mounting shaft bearings by applying pressure to the outer race, mounting bearings into a housing by applying pressure to the inner ring, loose fits, tight fits, housings that are out-of-round and bearing seats with a poor finish.

Electrical damage. The passage of electrical current from one ring to the other through the ball, even at low currents, can lead to electrically induced bearing damage over time. The high current of an arcing event causes flaking of the surface material and tempering or melting and re-hardening of the raceway, which forms craters in the raceway and damage to the rolling elements. Even if arcing leaves the bearing intact, the high temperatures wreck the lubricant, which damages the bearing.

Overloading. Whenever a bearing operates beyond rated capacity for temperature, speed or load, overloading occurs. This could be due to production demands, operator error or lower manufacturing standards. Don’t take too much of a load off, however. Bearings need a minimum load to function properly, particularly cylindrical roller bearings which are designed for heavier loads. The exception is preloaded bearings.

Overheating. Bearings have different clearances to allow for thermal expansion during operation, so selecting the correct bearing for the application is important.

Contamination. Watch out for moisture (either from humid environments or temperature swings that cause condensation), poor quality lubricant, acid, dust and dirt. They all cause corrosion.

Look for patterns

Bearing failure is rarely simple. What looks like the cause on first examination may not be what started it all, which is why a root cause analysis is an important way to prevent problems from occurring again. (Our essential guide to motor failure offers some quick tips on doing a root cause analysis.)

Luckily, the culprit leaves evidence behind. Each of the events that leads to bearing failure has a unique damage pattern, and a trained investigator can use clues such as denting, cracking, metal fragments, residues, grooves, marks and wear paths and hints such as noise, colour, shape, orientation, temperature and vibration to identify the perpetrator.

 

Share


Next：

Latest news

If you are interested in our products, you can choose to leave your information here, and we will be in touch with you shortly.


en_USEnglish
afAfrikaans sqAlbanian amAmharic arArabic hyArmenian azAzerbaijani euBasque belBelarusian bn_BDBengali bs_BABosnian bg_BGBulgarian caCatalan cebCebuano coCorsican hrCroatian cs_CZCzech da_DKDanish nl_NLDutch eoEsperanto etEstonian fiFinnish fr_FRFrench fyFrisian gl_ESGalician ka_GEGeorgian de_DEGerman elGreek guGujarati htHaitian Creole haHausa hawHawaiian he_ILHebrew hi_INHindi hmnMiao hu_HUHungarian is_ISIcelandic igIgbo id_IDIndonesian gaIrish it_ITItalian jaJapanese jvJavanese knKannada kkKazakh kmKhmer rwRwandese ko_KRKorean ckbKurdish kyKyrgyz loLao laLatin lvLatvian lt_LTLithuanian lbLuxembourgish mk_MKMacedonian mgMalgashi ms_MYMalay ml_INMalayalam mtMaltese miMaori mrMarathi mnMongolian my_MMMyanmar ne_NPNepali nb_NONorwegian nyNorwegian orOccitan psPashto fa_IRPersian pl_PLPolish pt_PTPortuguese pa_INPunjabi ro_RORomanian ru_RURussian smSamoan gdScottish Gaelic sr_RSSerbian stSesotho snShona sdSindhi si_LKSinhala sk_SKSlovak sl_SISlovenian soSomali es_ESSpanish suSundanese swSwahili sv_SESwedish tlTagalog tgTajik ta_INTamil tt_RUTatar teTelugu thThai tr_TRTurkish tkTurkmen ukUkrainian urUrdu ug_CNUighur uz_UZUzbek viVietnamese cyWelsh xhBantu yiYiddish yoYoruba zuZulu en_USEnglish