Roller Bearings are a type of rolling-element bearing that uses cylinders (rollers) to maintain the separation between the moving parts of the bearing (as opposed to using balls as the rolling element). The purpose of a roller bearing is to reduce rotational friction and support radial and axial loads.Roller bearings transmit loads using cylinder rolling elements, rather than balls, to maintain the separation between moving parts of the bearing.

Proper lubrication of rolling element bearings and gears is critical to long and profitable performance. The basics for successful lubrication of these machine elements are discussed. Procedures for correct selection of oil and grease lubricants are defined. Alternate systems for delivering proper lubrication are presented. Preventive and predictive methods for maintaining lubrication systems at their peak are suggested.

These versatile bearings can contain single or multiple rows of rolling elements; multiple rows can significantly improve radial load capacity. Also, the use of different roller shapes can further reduce friction and support both radial and axial loads.