Schaeffler YRTC - Function and Safety Checks Checking the Bearing Frictional Torque; Checking Running Accuracy

Schaeffler Technologies MON 100 19
Function and safety checks
Checking
the bearing frictional torque
The bearing frictional torque (rotational resistance) can only be
measured on a bearing that is already fitted, screw mounted and
fully supported.
When the fixing screws are tightened as specified, the bearing must
rotate evenly.
For bearing frictional torques, see TPI 120, High Precision Bearings
for Combined Loads, or Catalogue HR 1, Rolling Bearings.
The rotational resistance is also influenced by:
■ operating loads
■ screw tightening torque
■ geometrical accuracy of the fit and screw mounting surfaces
■ fit
■ temperature difference between the inner ring and outer ring
■ operating temperature
■ lubricant used
■ grease quantity
If the bearing is unusually difficult to move, loosen all of the fixing
screws and tighten them again in steps in a crosswise sequence.
This will relieve any distortion.
Functional inspection of the measuring system, see mounting
instruction MON 18, Axial/radial bearings YRTM with integral
angular measuring system.
Checking running accuracy The running accuracy can only be checked once the bearing is fitted
and with a dial gauge.
Incorrect running accuracy may be due to:
■ inaccuracies in the adjacent construction that are then trans-
mitted to the raceway system
■ eccentric mounting of the bearing with a fit clearance
■ fixing screws that are not tightened as specified
■ retaining screws that were not loosened before the rings were
mounted