Bearings

A bearing is a machine element which supports another moving machine element like a shaft. It allows a relative motion between the contact surfaces of the members, while carrying the load. Main two types of bearing are Rolling contact bearing and Sliding contact Bearing. This course mainly deals with the sliding contact bearings. Sliding contact bearings are also known as journal bearings, sleeve bearings, or plain bearings. In this type of bearing the surface of the shaft slides over the surface of the bush. Due to the relative motion between the contact surfaces, a certain amount of power is wasted in overcoming frictional resistance and if the rubbing surfaces are in direct contact, there will be rapid wear. To reduce the frictional resistance and the rapid wear of rotating surfaces, they are separated by a film of lubricating oil. The lubricant used to separate the journal and bearing is usually a mineral oil refined from petroleum, but vegetable oils, silicon oils, greases etc.

This course describes an introduction to bearings, its types and modes of lubrication to be used for the bearing. Also, it describes the details of sliding contact bearings, the effect of various parameters like temperature, friction etc. on the bearing functionality and the selection procedure of the bearing from the manufacturer's catalogue.