Cylindrical roller bearings come in various configurations, including single row, double row, and multi-row designs, each offering specific load-carrying capabilities and operational characteristics. Additionally, some cylindrical roller bearings feature a full complement of rollers, while others have a cage or separator to maintain proper roller spacing and alignment.

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.