1. Main performance The cross-section of the Y-shaped s […]
1. Main performance
The cross-section of the Y-shaped sealing ring is Y-shaped, which is a typical lip-shaped sealing ring.
According to the different ratios of the height and width of the section, it can be divided into wide type, narrow type, Yx type and so on.
If the heights of the two lips are equal, they can be divided into Y-shaped seals with equal height lip for shafts and holes, Y-shaped seals for shafts with unequal height lip, and Y-shaped dense rings for holes.
Y-shaped seals are widely used in reciprocating sealing devices, and their service life is longer than that of O-shaped seals. The applicable working pressure of Y-shaped sealing ring is not more than 40MPa, and the working temperature is -30~+80℃.
Working speed range: 0.01~0.6m/s when made of nitrile rubber; 0.05~0.3m/s when made of fluorine rubber; 0.01~1m/s when made of polyurethane rubber.
The sealing performance, service life and working pressure limit of Y-shaped sealing ring without retaining ring are all made of polyurethane rubber.
The performance characteristics of Y-shaped sealing ring:
1) Reliable sealing performance;
2) The friction resistance is small and the movement is stable;
3) Good pressure resistance, wide applicable pressure range;
4) Simple structure and low price;
5) Easy to install.
2. Sealing principle
The Y-shaped sealing ring relies on its open lip to stick to the coupling surface of the sealing pair, and is in linear contact. Under the action of the medium pressure, a "peak" contact stress is generated. The higher the pressure, the greater the stress. When the coupling parts move relatively at the working speed, a layer of sealing liquid film is formed between the sealing lip and the sliding coupling surface to produce a sealing effect. After the sealing lip is worn, it has a certain automatic compensation ability due to the effect of the medium pressure. Therefore, when the shaft extends out, the liquid in the "besieged area" is forced back to the small cavity, thereby forming a reliable sealing state and improving the sealing performance of the Y-shaped sealing ring. The higher the pressure in the "besieged area", the greater the contact stress of the secondary lip to the coupling surface, and the better the sealing performance.