The common seal of construction machinery is the seal ring, also known as oil seal. It can isolate the oil and prevent the oil from overflowing or passing through. There are various types of oil cylinders sold on the market. The following types of sealing rings are commonly used for hydraulic oil cylinders: dust ring, piston rod seal ring, buffer seal ring, guide support ring, end cap seal ring and piston seal ring. This article will briefly introduce the dust ring, piston rod seal ring and buffer seal ring.
1. Dust ring
The dust ring is installed on the outside of the end cover of the hydraulic cylinder to prevent external pollutants from entering the cylinder. According to the installation mode, it can be divided into snap in type and press in type. Snap in dust rings are the most common. The dust ring is stuck in the groove of the inner wall of the end cover, and is used under less harsh environmental conditions. The material of the snap in dust ring is usually polyurethane, and there are many variations in the structure, such as the double lip structure in the H and K sections. The press in dust ring is used under severe and heavy load conditions. Instead of being stuck in the groove, the polyurethane material is wrapped with a layer of metal to increase the strength and pressed into the end cover of the hydraulic cylinder. The press in dust ring also has many forms, including single lip and double lip.
2. Piston rod sealing ring
The piston rod seal ring, also known as the u-cup, is the main piston rod seal. It is installed inside the end cover of the hydraulic cylinder to prevent hydraulic oil leakage. The piston rod sealing ring is made of polyurethane or nitrile rubber. In some cases, it needs to be used with the support ring. The support ring is used to prevent extrusion deformation of the sealing ring under pressure. Piston rod seals are also available in a variety of variants.
3. Buffer seal ring
As an auxiliary piston rod seal ring, the buffer seal ring is used to protect the piston rod when the system pressure suddenly increases. There are three common types of buffer seals. Type A is a one-piece sealing ring made of polyurethane. Type B and type C are two-piece type, used to prevent seal extrusion and allow the seal to withstand higher pressure.
