Main performance

The section of Y-ring seal is Y-shaped, which is a typical lip seal.

It can be divided into wide type, narrow type and Y type according to the different proportion of height and width of the section.

According to whether the two lips are equal in height, they can be divided into Yx seal rings with equal height lips for shafts and holes, Y seal rings for rods and holes with unequal height lips, as shown in the figure:

Y-shaped sealing ring is widely used in reciprocating sealing device, and its service life is longer than that of O-ring.

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:

Reliable sealing performance;

Small friction resistance and smooth movement;

Good pressure resistance, wide applicable pressure range;

Simple structure and low price;

Easy installation

Sealing principle:

The Y-shaped sealing ring sticks to the coupling surface of the sealing pair with its open lip. When there is no internal pressure, a small contact pressure is generated only due to the deformation of the lip tip. In the case of sealing, every point in contact with the sealing medium has a normal pressure equal to the medium pressure, so the bottom of the lip ring will be subject to axial compression, the lip will be subject to circumferential compression, and the contact with the sealing surface will become wider, while the contact stress will increase. When the internal pressure rises again, the distribution form and size of the contact pressure will further change, and the lips will fit more closely with the sealing surface, so the sealing performance will be better. This is the "self sealing effect" of the Y-ring. Due to this self sealing effect, a Y-shaped ring can effectively seal 32MPa high pressure.

The Y-shaped seal ring is mainly used for reciprocating sealing. According to its working principle, when installing the Y-shaped seal ring, the lip must face the side with high pressure to play a role, so the Y-shaped seal ring can only play a role in one direction.

When the coupling piece moves at the working speed, a seal oil film is formed between the seal lip and the sliding surface. The existence of the oil film can improve the friction condition of the seal ring and reduce the wear; The oil film plays a sealing role in the pneumatic seal.

The leakage of piston in reciprocating stroke is different. When the internal pressure is low, the leakage in the extraction stroke increases with the increase of the internal pressure; The pressing stroke decreases with the increase of internal pressure. When the internal pressure is large enough (about more than 7.5MPa), the leakage will no longer change with the internal pressure.

When the internal pressure p1 of Y-shaped seal ring is low, the friction force increases with the increase of internal pressure. When the internal pressure is large enough, the friction will not change much. If the lubrication is good, there is even a downward trend. The starting friction test results of Y ring abroad show that the starting friction has little relationship with the stopping time, which is the biggest difference from O ring.

This is extremely beneficial for intermittent motion machinery. At the same time, when the internal pressure is low, the starting friction increases with the increase of the internal pressure. When the internal pressure exceeds 5MPa, the starting friction is independent of the internal pressure. Therefore, for machinery with intermittent high pressure, there will be no problem of excessive starting friction. After the sealing lip is worn, due to the effect of medium pressure, the lip has certain automatic compensation ability.