How are engine bearings lubricated?

Engine bearings are lubricated primarily through a pressurized oil system. Engine oil is pumped from the oil sump through galleries to the bearings, creating a thin film that reduces friction between the bearing surfaces and the crankshaft. The oil not only lubricates but also helps dissipate heat and carries away contaminants. In some designs, additional features like oil jets may be used to ensure adequate lubrication under varying operating conditions.