A bearing is a machine element that constrains relative motion to only the desired motion, and reduces friction between moving parts. The design of the bearing may, for example, provide for free linear movement of the moving part or for free rotation around a fixed axis; or, it may prevent a motion by controlling the vectors of normal forces that bear on the moving parts. Most bearings facilitate the desired motion by minimizing friction. Bearings are classified broadly according to the type of operation, the motions allowed, or to the directions of the loads (forces) applied to the parts.

AP TM ROLLER BEARINGS SERVICE LIMITS Diesel Locomotives Steel/Polymer Cage with HDL/EcoTurn Seal Diameters Are Averages Amount Of Grease (Ounces) Class And Size Roller Assembly Outer Ring (Cup) Backing Ring Each Roller Assembly Around Spacer Inboard Total Quantity Max.