Oil seals are essential rotary shaft sealing components widely used in automobiles, engineering machinery, and hydraulic systems. Composed of a rubber lip, metal frame, and garter spring, they serve to prevent internal oil leakage and block external dust, water, and impurities. This article systematically introduces the definition, structural composition, common materials including NBR, FKM, VMQ and PU, as well as mainstream classifications of oil seals. It also analyzes the main causes of oil seal failure, summarizes key principles for model selection, and puts forward standard installation and daily maintenance guidelines. Proper material matching, accurate dimension selection, standardized mounting and reasonable application conditions are critical to extending the service life of oil seals, reducing equipment failure and ensuring stable mechanical operation.
