In foil bearings, a shaft is supported by the foil loaded with the springs, known as compliant. As the shaft rotates at the high speed breaks the contact between the shaft and the foil, by forcing the foil away from shaft. Under normal circumstances, the high pressure is employed to break the contact between the two, which is generated through the means of rotation. Due to the separation between the shaft and the foil, an adequate space occurs between the two and therefore, wear and tear of the machinery is reduced to a large extent.

Since, the foil bearings usually operate ate the high speed; hence, turbo machinery is one of the major applications of foil bearings. The features of foil bearings include:

• Reliability and authentication
• A high percentage of efficiency can be obtained due to the less amount of friction generated.
• Noiseless operation
• No external system is required to support the operation of foil bearings.
• Foil bearings are capable of working effectively even at the speed higher than that of the critical speed.

There are some drawbacks of foil bearings like high speed is required for proper functioning and lower capacity, if compared to other bearings.