Hello Professionals,

Motor/timing belt drive in calander

DE bearing is spherical roller bearing 21316 E/c3 (20 Rollers), seized and the shaft got broken, Temperature was +200 C, the damage started with BPFO in the afternoon, 6 hours later...... catastrophic failure.

investigation of the case, we found another positions has 21316 cc/c3 (19 Rollers) and we never experienced a catastrophic failure !

Could an Expert help me in justifying the case

Thank you in advance




Original Post

Though more details are required( photos/spectrum etc) but I suspect sudden fluctuation in load or process parameters may have dislocated bearing in the housing causing high friction / temperature resulted in bearing seizure. 

Also check the greasing schedule for the bearings. 


more info: Motor 140 HP & 1200 rpm

the catastrophic failure happened many times , only with the 21316 E/c3 ( 20 rollers) , so as soon as the BPFO appear, some hours later and it is died !

Could the number of rollers { 21316E/c3 (20Rollers) & 21316 CC/c3 , (19 Rollers)}  play a role in the carrying load capacity and skidding characteristics which leads to fast failure ?





i did not measure and compare, bu it is a good direction to search, but which load exactly should i compare ?

Fap=maximum permissible axial load [kN]

Fr=radial load [kN]

P=equivalent dynamic bearing load [kN]

P0=equivalent static bearing load [kN]

Pm=equivalent minimum load [kN]

****i did not work with these calculations since 20 years ....out of my scope, but i will do my best go through...



You should use some pro tension meter like Trummeter, which has its own calculator for suitable belt tension in N or in Hz. Or measure the force directly at the installation. I think the measured belt force on the Trummeter means just force on one side of the belt so you should multiple it roughly by 2 (or consider angles for more precise value). For the new belt installation, the tension value should also be multiplied by 1,3.

When you get this value, it should be reasonably lower than the radial load bearing values.

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