1. Main performance
The section of the Y-shaped seal ring is Y-shaped, which is a typical lip shaped seal ring.
It can be divided into wide type, narrow type and Yx type according to the different proportion of height and width of its section.
According to whether the two lips are equal in height, they can be divided into Y-shaped seal rings with equal height for shafts and holes, Y-shaped seal rings with unequal height for shafts and Y-shaped seal rings for holes,
Y-shaped sealing ring is widely used in reciprocating sealing device, and its service life is longer than that of O-ring. The applicable working pressure of Y-shaped seal ring is not more than 40MPa, and the working temperature is – 30~+80 ℃.
Working speed range: 0.01~0.6m/s when nitrile rubber is used; 0.05~0.3m/s when fluororubber is used; When polyurethane rubber is used, it is 0.01~1m/s.
Polyurethane rubber is the best material for sealing performance, service life and working pressure limit of Y-shaped sealing ring without retaining ring.
Performance characteristics of Y-shaped seal ring:
1) Reliable sealing performance;
2) Small friction resistance and smooth movement;
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 sticks to the coupling surface of the sealing pair with its open lip and is in linear contact. Under the action of medium pressure, “peak” contact stress is generated. The higher the pressure, the greater the stress. When the coupling piece moves relative to each other at the working speed, a layer of sealing liquid film is formed between the sealing lip and the sliding coupling surface, thus producing the sealing effect. After the sealing lip is worn, it has certain automatic compensation ability due to the effect of medium pressure. Therefore, when the shaft extends, it forces the liquid in the “encircled area” to press back into the small chamber, thus forming a reliable sealing state and improving the sealing performance of the Y-shaped seal ring. The higher the pressure in the “containment area”, the greater the contact stress between the auxiliary lip and the coupling surface, and the better the sealing performance.