The cylinder seal is a very important component in the hydraulic system to prevent the leakage of hydraulic oil and maintain the pressure of the system. According to their function and structure, cylinder seals can be divided into the following categories:
1. Piston Seals
Function: It is used for sealing between piston and inner wall of cylinder to prevent leakage of hydraulic oil from high pressure side to low pressure side.
Common types:
O-ring: the most common seal, simple structure, easy to install.
U-ring: Better extrusion resistance, suitable for high pressure environments.
Y-ring: has good self-lubricating performance, suitable for high-speed movement.
Gray ring (PTFE + O-ring) : a combination of PTFE and O-ring, with good wear resistance and low friction characteristics.
2. Rod Seals
Function: Used for sealing between the piston rod and the cylinder end cap to prevent hydraulic oil from leaking from the inside of the cylinder to the outside.
Common types:
Sterseal (PTFE + O-ring) : a combination of PTFE and O-ring, with good wear resistance and low friction characteristics.
V-ring: Suitable for high pressure and high speed environment, with good extrusion resistance.
Dust ring: used to prevent external dust and impurities from entering the inside of the cylinder, usually used in conjunction with the piston rod seal.
3. Guide Rings
Function: Used to support piston and piston rod, reduce friction and wear, prevent eccentric movement.
Common types:
PTFE guide ring: has good wear resistance and low friction characteristics.
Nylon guide ring: high strength and wear resistance.
4. Static Seals
Function: Used for sealing between stationary parts such as cylinder end cover and flange to prevent hydraulic oil leakage.
Common types:
O-ring: The most common static seal, suitable for a variety of static connection parts.
Square ring: suitable for high pressure and large diameter static seals.
5. Dust Seals
Function: Used to prevent external dust, impurities and moisture into the inside of the cylinder, protect the piston rod and seal.
Common types:
Single lip dust ring: with a single seal lip, suitable for general dust requirements.
Double lip dust ring: with two sealed lips, better dust effect, suitable for harsh environments.
6. Buffer Seals
Function: Used to reduce the impact of the piston at the end of the stroke, to protect the cylinder and seals.
Common types:
Buffer ring: Usually made of elastic material, installed at the end of the piston.
7. Rotary Seals
Function: Used for sealing between rotary shaft and cylinder to prevent leakage of hydraulic oil.
Common types:
Oil seal: suitable for the sealing of rotary shaft, with good wear resistance and oil resistance.
8. Combo Seals
Function: It combines the functions of piston seal and piston rod seal, usually composed of multiple seals.
Common types:
Grey-ring + Steffen: Combining the advantages of Grey-ring and Steffen, suitable for high pressure and high speed environments.
9. Special Seals
Function: Used for sealing under special working conditions, such as high temperature, low temperature, corrosive media, etc.
Common types:
Fluoro rubber seals: suitable for high temperature and corrosive media.
Silicone rubber seal: suitable for low temperature environment.
Sum up
The classification of cylinder seals is mainly divided according to their function, installation position and material characteristics. Different types of seals play different roles in the hydraulic system to ensure the sealing performance and reliability of the system. Choosing the right seal is very important to improve the efficiency of the hydraulic system and extend the life of the equipment.