Spherical roller bearing has barrel-shaped rollers. It is capable of handling heavy loads and are used where there is a vibration between different moving components. The flexibility in the design as the inner and outer races move independently of each other compensating vibration. In spite of what their name may suggest, circular roller bearings are not really round in shape. The moving components of the circular roller course are fundamentally round. But have a (barrel-like) profile that makes them appear like cylinders that have been marginally over-inflated.
Flour mills, cement mills, gearboxes of rolling mills, hangars support wheels, etc.