Many one-way needle roller bearings have small holes in the inner and outer rings. What's the function of these small holes?
The basic structure and NU type cylindrical roller bearing inner ring bearing the same, but because of the needle, the volume can be reduced, and can bear large radial load to the bearing without inner ring shaft mounting surface with suitable precision and hardness as the raceway surface
It should be the oil storage hole, whose main function is to store grease and lubricate the needle roller.
It's all oil holes, but if it's needle roller bearings, there should be very little oil holes. We also do one-way needle roller bearings, but there are no oil holes, there are oil holes are generally reflected in other series
