Classification of Hydraulic Cylinder Seals:
The hydraulic cylinder seal is installed on the shaft of the hydraulic pump and the hydraulic motor to prevent the working medium from leaking out of the shell along the shaft and the external dust from intruding into the body.
- Piston Seal:
The main function of piston seal is to seal the gap between the piston and the cylinder and prevent hydraulic oil leakage. The piston seal is the main seal in the hydraulic cylinder, which bears pressure in both directions, and is one of the most important seals that the hydraulic cylinder can withstand the pressure value. The requirements for piston sealing are good sealing effect, good pressure holding effect under static conditions, strong pressure bearing capacity during movement, anti-extrusion, low friction coefficient, long service life, etc.
- Static Seal:
The static sealing ring of the end cover is installed at the contact position between the outer circle of the end cover and the inner wall of the hydraulic cylinder; the static sealing ring of the piston is installed between the piston and the piston rod. They are all static sealing rings in hydraulic cylinders. The static seal of the end cover prevents the hydraulic oil from leaking out of the gap between the end cover and the cylinder barrel. The seal is two-way pressure-bearing to prevent hydraulic oil from leaking between the piston and the piston rod. It requires strong anti-extrusion ability and good sealing effect.
- Rotating Seal:
It is installed on the shaft of the hydraulic pump and the hydraulic motor to prevent the working medium from leaking out of the shell along the shaft and the external dust from intruding into the body. The general oil seal has a poor pressure bearing capacity, generally 0.2-0.3MPa, the pressure bearing capacity of the fluorine rubber pressure oil seal is 0.25-0.7MPa, and the maximum pressure bearing capacity of the OTHELLO medium and high pressure oil seal is 40MPa.
The Main Cause Of Seal Leakage:
- Installation Problem:
1. The wrong installation direction of the seal leads to leakage.
2. During installation, foreign matter or dust in the pipeline enters the sealed cavity and causes leakage.
3. Poor assembly causes damage to the seals and leaks.
4. Scratches on the surface of the seal cause leakage.
5. The piston rod is not concentric, and the eccentric load causes leakage.
- Seal Selection Problem:
1. The pressure is too high and the hardness of the seal is too small to be extruded out of the metal groove.
2. The sealing material and the medium are compatible, and the sealing part is softened or dissolved.
3. The seal is used in conditions where the temperature is too high, and the sealing material is carbonized.
4. The low temperature causes the sealing material to harden and shrink to cause leakage.
5. The use line speed is too high, causing the seal to heat up, dry grinding, carbonization and leak.
6. Poor lubrication under working conditions causes the seal to wear and leak.
7. The cavity used is subject to vibration and causes leakage.
8. Leakage caused by seal wear caused by dust.
9. The hardness of the seal is too high to completely fill the metal groove to cause leakage.
10. The size of the seal does not match the metal groove causing leakage.
11. Choose seals that have been stored for a long time and are aged to cause leakage.