- Main bearings, also known as crankshaft bearings, are designed to support the crankshaft within the engine block. They are positioned at the main bearing journals of the crankshaft and provide support for the rotational motion of the crankshaft. Main bearings are subjected to radial loads and are crucial for maintaining the alignment and smooth rotation of the crankshaft.

The primary function of a bearing is to enable the controlled transfer of loads and motion while minimizing friction and wear. Bearings achieve this through the use of rolling elements, such as balls or rollers, or through sliding surfaces, depending on the specific type of bearing. By doing so, bearings help to maintain the integrity and alignment of rotating shafts, axles, and other mechanical components, ensuring smooth and efficient operation of the machinery.