The sealing methods between the hydraulic cylinder barrel and the piston are usually as follows:
1、 Piston seal
Piston sealing is one of the most common sealing methods in hydraulic cylinders, located between the piston and the cylinder barrel. The main function of piston sealing is to seal the gap between the piston and the cylinder, preventing hydraulic oil leakage. Piston seals are usually made of elastic materials such as rubber or polyurethane, which have good elasticity and wear resistance. There are various forms of piston seals, such as DAS type combination seals, U-shaped seals, Y-shaped seals, etc. The most suitable form should be selected according to different usage environments.
2、 Piston rod seal
The piston rod seal is located between the piston rod and the sealing ring, and its main function is to prevent hydraulic oil leakage. There are also many types of piston rod seals, such as one-way seals, two-way seals, V-shaped seals, etc. Unidirectional sealing rings are mainly suitable for one-way movement when the rod extends, while bidirectional sealing rings are suitable for reciprocating movement and have two sealing lips, making the sealing performance more reliable. V-shaped seals are widely used in piston rod seals of hydraulic cylinders due to their simple structure and excellent sealing performance.
3、 Static seal
Static seals are mainly installed at the contact position between the outer circle of the end cap and the inner wall of the hydraulic cylinder, as well as between the piston and the piston rod. The common static sealing ring is an O-ring with a retaining ring. O-ring seals have good elasticity and sealing performance, and can withstand certain pressures. The function of the retaining ring is to prevent the sealing ring from being squeezed into the sealing gap due to excessive deformation. Static sealing plays a crucial role in hydraulic cylinders, as it prevents hydraulic oil from leaking out of the gap between the end cap and cylinder barrel, ensuring the normal operation of the hydraulic cylinder.
4、 Other sealing methods
In addition to the common sealing methods mentioned above, there are also some special sealing methods, such as rotary seals, combination seals, etc. Rotary seals are usually installed on the shafts of hydraulic pumps and hydraulic motors to prevent the working medium from leaking out of the housing along the shaft. Combination sealing is the combination of multiple sealing methods to improve sealing performance. These special sealing methods have unique advantages in specific application scenarios.
In summary, there are various sealing methods between hydraulic cylinders and pistons. Choosing the appropriate sealing method is crucial for ensuring the normal operation and extending the service life of hydraulic cylinders. When choosing a sealing method, it is necessary to comprehensively consider factors such as working pressure, medium, temperature, speed, as well as the wear resistance and corrosion resistance of the sealing components.