Bearings with Cylindrical or Crowned outer ringLR series Track Roller Bearings are also called CAM ROLLERS,Website:http://www.rihooindustry.com, used in the heavy loads track or used as an idler wheel to meet the particular application that the friction should be reduced. The outer diameter surface of bearings is shaped to the crowned runner surfaces with R500 ( suffix U ). They can take the metal shield (suffix KDD) or rubble seal (suffix NPP) to prevent the dust.LR bearings are made of the high – quality bearing steel, some types can be made from the corrosion resistance stainless steel. Also bearings can be provided with concentric or eccentric pivot.