Construction machinery is inseparable from the oil cylinder, and the oil cylinder cannot be separated from the seal. A common seal is a sealing ring, also called an oil seal, which acts as a barrier against oil and prevents oil from overflowing or passing through. Here, the editor of the mechanical community has compiled some common types and forms of cylinder seals for everyone.
Common seal rings used in hydraulic cylinders are the following types: dust ring, piston rod seal, buffer seal, guide support ring, end cover seal and piston seal.
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 method, it can be divided into a snap-in type and a press-in type. Pay attention to mechanical engineers (MechanicalEngineers) to get more mechanical knowledge.
Basic form of snap-in dust ring
The snap-in dust ring is the most common. As the name suggests, the dust ring is stuck in the groove on 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 variants of the structure. For example, the H and K cross-sections have a double-lip structure, but they are inseparable.
Some variants of snap-in dust rings
The press-in dustproof ring is used under severe and heavy load conditions. It is not stuck in the groove, but is wrapped with a layer of metal to increase the strength of the polyurethane material and pressed into the hydraulic cylinder end cover. There are also many types of press-in dust rings, including single lip and double lip.
Press-in dust ring and some variants
Piston rod seal
The piston rod seal is also called a U-shaped cup, which is the main piston rod seal, installed inside the end cover of the hydraulic cylinder, to prevent leakage of hydraulic oil. The piston rod sealing ring is made of polyurethane or nitrile rubber. In some cases, it needs to be used with a support ring (also called a retaining ring). The support ring is used to prevent the sealing ring from being squeezed and deformed under pressure. There are also many variants of piston rod seals.
Common form of piston rod seal
Some variants of piston rod seals
Buffer seal
The buffer seal is used as an auxiliary piston rod seal to protect the piston rod when the system pressure suddenly increases. There are three common types of buffer seals. Follow us: mechanical engineers, focusing on the sharing of information on the machinery industry, professions, and occupations, serving millions of engineers in the manufacturing industry. Type A is a single-piece sealing ring made of polyurethane. Type B and Type C are two-piece, used to prevent seal extrusion and allow the seal to withstand higher pressure.
Several common forms of buffer seals
Guide support ring
The guide support ring is installed on the end cover of the hydraulic cylinder and the piston to support the piston rod and the piston, guide the piston to move linearly, and prevent metal-to-metal contact. There are plastics, bronze coated with PTFE and so on.
Guide support ring for hydraulic cylinder end cover and piston respectively
End cover sealing ring
The end cover sealing ring is used to seal the cylinder end cover and the cylinder wall. It is a static seal to prevent hydraulic oil from leaking from the gap between the end cover and the cylinder wall. Usually consists of a nitrile rubber O-ring and a support ring (retaining ring).
End cover sealing ring
Piston seal
The piston seal ring is used to isolate the two chambers of the hydraulic cylinder and is the main seal in the hydraulic cylinder. Usually two-piece, the outer ring is made of PTFE or nylon, and the inner ring is made of nitrile rubber. Pay attention to mechanical engineers (MechanicalEngineers) to get more mechanical knowledge. There are also many variations, including the use of bronze coated with PTFE, and so on. On single-acting cylinders, there are also polyurethane U-shaped cups.
Several common forms of piston seals
