Labyrinth seal

A labyrinth seal is a non-contact seal in which rotating and stationary parts form interlocking chambers and narrow gaps. The repeatedly deflected gap path presents high flow resistance to entering contaminants and escaping lubricant; the passages are often grease-packed so the grease acts as a barrier and flushes dirt outward during relubrication. With no rubbing contact, labyrinth seals run virtually friction- and wear-free with no lip-imposed speed or temperature limit, suiting high peripheral speeds and long service intervals, typically on plummer block housings, fans, pumps and gearboxes. Against standing water or pressure they are not tight on their own – contact seals or combined systems are then required.