Rolling bearing failure modes and calculation principles

Rolling bearing load analysis for deep groove ball bearing as an example for analysis. As shown in figure 12 - 19, bearing radial load Fr effect, rolling body under load is different, in the lowest position of the rolling element load is the largest. By theoretical analysis, load the biggest load of roller for F0 material ( 5 / z) Fr, z for the number of roller type. When outer ring inner ring rotates, roller rotation and revolves around the axis of the bearing, so the inner and outer ring and the contact point position of the constantly changing roller, A point on the contact surface of raceway and rolling element contact stress as A cyclical change, roller and spinning ring by the periodic change of contact stress the pulsating cycle, the fixed ring on the stability of the point A maximum contact stress pulse cycle. Failure forms of rolling bearing failure pattern mainly has the following three: ( 1) Fatigue pitting and roller ring groove under the contact stress of the pulsating cycle, when the stress value or stress cycle number more than a certain value, the contact surface contact fatigue pitting. Pitting the bearing vibration and noise in operation, the rotation accuracy reduces the working temperature, and the normal work of lose bearing capacity. Contact fatigue pitting is the main failure form of rolling bearing. ( 2) Too much plastic deformation in the static load of or under the action of impact load, the ring raceway and rolling body may occur plastic deformation, the race pits or squished roller, lower the moving accuracy, vibration and noise, lead to bearing cannot work normally. ( 3) Wear in bad lubrication, sealing unreliable and dusty conditions, or roller ring raceway easy generation of abrasive wear, high speed thermal adhesion wear occurs, will also lead to tempering roller bearing overheating. In addition, due to cooperate with rolling bearings, installation, disassembly and maintenance is undeserved, still can cause other forms such as bearing components burst failure, should also take corresponding measures to prevent. Calculation standards for the main failure form, the calculation of rolling bearing rule is: ( 1) For the average speed ( n> 10 r / min) Bearing, fatigue pitting is the main failure forms, should be the life calculation. ( 2) For low speed ( n≤10 r / min) Overloading or big impact work under the condition of bearing, the main failure form of plastic deformation, should carry on the static strength calculation. ( 3) For high speed bearing, in addition to the fatigue pitting adhesion wear is also the important failure forms, so besides should life calculation to check its speed limit.