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2020

Working principle of rotary seal

Rotary seal is a kind of dynamic seal. It is used to seal rods, shafts, pins, rotary joints, etc. that rotate or swing. It is composed of a slip ring filled with PTFE and a rubber O-ring that provides elastic force. It is a two-way rotary sealing ring that can withstand pressure on both sides or alternating pressure, rotary hydraulic rotation exists in various industrial fields such as construction machinery, construction machinery and automotive equipment.

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Rotary sealIt is a kind of dynamic seal. It is used to seal rods, shafts, pins, rotary joints, etc. that have rotating or swinging motion. It is composed of a slip ring made of filled polytetrafluoroethylene and a rubber O-ring that provides elasticity. It is a two-way action that can withstand pressure on both sides or alternating pressure.Rotary sealThere is a rotary hydraulic rotation in various industrial fields such as construction machinery, construction machinery and automotive equipment.

Rotary sealAlso known as oil seal. It can prevent the bearing in the melting of the grease flow, but also to prevent the dust and impurities intrusion. In order to adapt to the rotating seal of various working conditions, the materials used are different, and the structure of the seal is also diverse. The sealing pressure of the high-pressure oil seal is as high as 1~1.2MPa, the sealing pressure of the ordinary oil seal is zero or about 0.05MPa, and some have high pressure, up to tens of MPa, and the sealing speed can be from zero speed to thousands of speed per minute.

There are many types of rotary seals and different structures. They are often used in rotary seals with no pressure or low pressure, and are often called monotypes. The material of the skeleton and lip can be freely selected according to the needs to form the required oil seal, which is often called a combined seal. In the free state, the inner diameter of the oil seal lip is smaller than the outer diameter of the journal. Even if there is no spring tightening, a certain radial pressure is formed on the outer surface of the journal.

When the shaft rotates, a 0.3-0.5mm wide sealing band is formed between the oil seal lip and the journal, and an oil film with a thickness of about 0.003mm is maintained in the annular sealing band. Maintaining a thin and uniform oil film between the lip and the journal is the best state for the oil seal. Maintaining the existence of the oil film ensures the effectiveness of lubrication and sealing, and also ensures the sealing and anti-dust effect of the oil seal.