Spindle bearings

There are three types of spindle bearings- hydrodynamic bearings, hydrostatic bearings and antifriction bearings. A thin film of oil is introduced between the spindle and the journal in a hydrodynamic bearing and hence they are also known as journal bearings. The main application of such bearings is in carrying loads when machine capacity is low. Here frequent starting and stopping of the spindle is not required. One example is in grinding machines. When the spindle rotates, the oil film is moved to wedge-shaped cavities between the spindle and the bearing, thus increasing the oil pressure. A thick film of oil is used hydrostatic bearings. This is used in grinding machines and fine boring machines. For high speed and heavy load applications, antifriction bearings are used. The main advantages of this type of bearings are low friction, less wear and tear, moderate dimensions, easy to replace and high reliability.