EFFECTS OF LOW-SPEED ON ROLLER BEARING FATIGUE LIFE

True lest series were conducted to study the effect of low speed and h igh load on the rolling-element fatigue life of 30 min and 40 mm bore cylindrical roller bearings at inner race speeds from 19 to 3725 ,pm a nd lubricant film parameter Lambda (Lambda) ratios from 0.03 to 1.2. M aximum Hertz stress ranged from 2.24 to 4.2 GPa (325 to 609 ksi). A to tal of 387 bearings were tested out of which 123 failed. Bearing life was directly related to transit contact time (TT). As TT increases, li fe also increases. That is, bearings which run slower have longer live s in terms of bearing revolutions. A transit time life factor (LF) is suggested to be used with STLE life factors for slow moving industrial equipment roller bearings. Both TT and the total number of stress cyc les affect the magnitude of measured surface residual stress induced d uring bearing operation. There was a relation observed between the dec omposition of retained austenite and induced compressive residual stre ss measured on the inner-race surface.