Engine System

Oil seals are primarily employed in engine systems for sealing rotating shafts. Their elastic sealing lips, in conjunction with self-tightening springs, form a dynamic sealing interface by tightly conforming to the shaft surface. This prevents lubricant leakage and isolates external contaminants from infiltrating core components such as crankshafts and valve stems. Taking crankshaft front and rear oil seals as an example, these typically employ a dual-lip fluorocarbon rubber construction (TC type). The primary lip prevents engine oil leakage that could contaminate the environment or infiltrate the combustion chamber, while the secondary lip intercepts dust and moisture, averting bearing dry friction and seizure caused by lubricant loss. Valve oil seals are particularly critical, precisely regulating oil flow at the valve guides. This prevents excessive oil ingress into the combustion chamber – which causes blue smoke from the exhaust, spark plug fouling, and power loss – while ensuring minimal oil lubricates the valve stems to maintain smooth valve train operation. Furthermore, the shaft ends of auxiliary components such as the oil pump and water pump similarly rely on oil seals to maintain sealing integrity. Failure here can lead to insufficient lubricating oil pressure, accelerating wear on piston rings and cylinder walls, or even causing cylinder scoring.