Why are sealed bearings favored over the unsealed alternative? Why ought sealed ball bearings be preferred to unsealed ones? What advantages can sealed ball bearings offer?
Most effective sealing is obtained with optimum shaft surface finishes. The sealing efficiency is affected by the direction of the finish tool marks and the spiral lead. Best sealing results are obtained with polished or ground shafts with concentric (no spiral lead) finish marks. If you must use shafts with spiral finish leads, they should lead toward the fluid when the shaft rotates.

The oil seal turbo, also referred to as the turbocharger oil seal, is a vital component in turbocharged engines. It is designed to contain the oil within the turbocharger, preventing leaks and ensuring the efficient operation of the turbo system. The oil seal turbo plays a key role in maintaining the proper lubrication and cooling of the turbocharger, contributing to the performance and durability of the engine.