In summary, main bearings are primarily responsible for supporting the rotational motion of the crankshaft and withstanding radial loads, while thrust bearings are designed to counteract axial forces and maintain the axial position of the crankshaft. Both types of bearings play critical roles in ensuring the smooth and reliable operation of engines and machinery.

   - Ball Bearing: Ball bearings, including deep groove ball bearings, utilize spherical balls as rolling elements that move between inner and outer raceways. They are primarily designed to support radial loads, with some designs capable of handling limited axial loads. Ball bearings are commonly used in applications where smooth and efficient rotation is required, such as in electric motors, pumps, and gearboxes.