Single row deep groove ball bearings for hammer drills
For the armature and output shafts single row deep groove ball bearings are normally used. They can be fitted with light or contacting rubber seals dependant upon speed and friction torque requirements. Polymer cages are used where vibration and poor lubrication is a problem. Greases are selected to give good performance with low leakage
under high vibration conditions
. Internal radial clearance will depend on the fitting tolerances required.