Input shaft bearings

Input shaft bearings are selected without considering external radial/axial loads or moments. Please consult factory for advice in case the input shaft is subjected to external loads.

Planet bearings

All planet gear bearings are selected for L10 life of 5000 hrs. assuming an input speed of 1500 rpm to the gear box. When a gear unit is selected with service factor, the bearing life also increases and hence use the following formula to get the adjusted bearing life.

L10a = L10r(Sf)³
Where
L10r = bearing life of the gear unit in hrs with Sf =1=5000 hrs.

L10a = adjusted bearing life of the selected unit in hrs.

Output shaft bearings

Output shaft bearings are selected for a minimum L10 bearing life of 5000 hrs for the allowable overhang load listed with reference rpm (Nr) at 300 for S-Series, 80 rpm for D-Series, 20 rpm for T-Series and 5 rpm for Q-Series gear units.

For calculating the actual bearing life:

L10a = 5000 (Fra/Fr)³ (Nr/Na)

Where :

Fra = Allowable radial load
Fr = Applied Radial Load
Nr = Reference rpm
Na = Actual rpm