Use Of Combined Seals in Construction Machinery Repair Kits

Generally speaking, the repair kit for construction machinery seals is composed of O-rings, hole seals, shaft seals, dust rings, support rings, and guide rings. The details are as follows:

1. O-ring: It is usually used as a static seal. If the working pressure exceeds 20MPa, it is generally necessary to add a retaining ring made of (PTFE) or polyoxymethylene (POM).

2. Seals for holes: common V-rings, U-rings, Gree rings, combined seals, etc. that is: V-rings for holes, Glyd rings for piston, U-rings, U-rings for rod Combined seals;

V-rings are generally used in heavy-duty hydraulic cylinders and have reliable sealing performance. They usually need to be installed in pairs, with open grooves. The guide element of this type of combined sealing ring is usually a copper sleeve.

U-rings are widely used and have reliable sealing performance. Many engineering hydraulic cylinders and hydraulic hydraulic cylinders are selected for this type of sealing. Open grooves can also be used in closed grooves, and many of the guiding elements are guided belts (DST).

Glyd rings are generally used in sealing environments where internal leakage requirements are not too high, because the material of this sealing ring sealing slip ring is mostly copper powder (PTFE) more than 30%. This mixed material is under low pressure. Its internal leakage value is larger, and the higher the pressure, the better the sealing effect. Servo cylinders generally use this type of sealing ring products. Most of its guide elements use guide strips (DST).

There are many types of combined sealing rings. Many manufacturers imitate the DAS type combined sealing ring of Baose Xiaban Company. They are generally used in hydraulic cylinders with compact structure and size. This combined sealing ring has guide elements, and after using this combined sealing ring, no other guiding elements can be added.

3. Shaft seal: common Y-shaped circles for shafts, U-shaped circles for shafts, step seals, etc.

Step seal: This kind of sealing ring is widely used, generally used as the seal (main seal) in the piston rod sealing system. . (generally need to be used in combination with other sealing rings)

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U-shaped ring for shaft: This sealing ring can be used alone. It can be used alone when the working pressure of the system does not exceed 20MPa. If it is used alone, it is generally necessary to add a retaining ring. It can also be used as a secondary seal, and a step seal is used in the front as the main seal.

V-ring for shaft: Its usage is similar to that of V-ring for piston, it needs to use open groove, and the guiding element generally adopts copper sleeve.

4. Dust ring: There are two common types of dust rings: double-acting dust rings and single-acting dust rings.

There are two main points to pay attention to when choosing a dust ring, one is to choose according to the selection of shaft seals, and the other is to choose according to the working environment.

Double-acting dust rings are generally made of polyurethane; dust rings with skeletons are generally used in extremely harsh environments.

There are several common piston rod seal combinations:

A. Step seal + U-ring + single-acting dust ring

Most of the hydraulic cylinder piston rod part seals are of this type.

B, V-ring + dust ring

Mostly used in heavy-duty hydraulic cylinders, used in combination with V-rings for EK-type holes, hydraulic cylinders.

C. Step seal + Step seal + double-acting dust ring

This seal combination is widely used, but most of them are used in hydraulic cylinders that require low friction resistance and fast running speed.