- When the machine is working, the hydraulic seal acts as a barrier to the medium, so what is the medium?
(1) The medium can be oil, water, and gas. They are the key to the transmission of power in mechanical equipment. The medium cannot directly contact the parts in the equipment, so the medium and the parts need to be isolated, and the seal is to seal the medium And the parts that exist.
(2) The medium and the seal are in an interactive relationship. The equipment must operate normally without allowing the medium to leak into the seal. This is a very critical factor.
- Interrelation of media and seals:
1. Under the action of medium pressure, the stress distribution on the main contact surface is approximately a quadratic parabolic curve, and the peak stress remains almost at the midpoint of the contact surface, but the curves on the left and right sides are asymmetric.
2. When the medium pressure increases from 1 MPa to 2 MPa, the peak stress on the main contact surface increases from 7 MPa to 9 MPa. This is due to the fact that the seal ring will produce more pressure when subjected to higher medium pressure in the axial direction. With large secondary compression, the increase in peak stress is greater than the increase in medium pressure. As the medium pressure increases, the contact width of the main contact surface increases slightly.
3. With the contact center point as the center, the stress value gradually decreases from the peak point to both sides, and increases with the increase of the medium pressure, and the contact width of the side contact surface also increases with the increase of the medium pressure. Therefore, the second compression of the sealing ring caused by the medium pressure is the main factor for the stress on the side contact surface.
4. The peak stress on the main contact surface increases with the increase of the medium pressure and is always higher than the medium pressure. Therefore, the sealing ring can still prevent the leakage of the medium when the medium pressure suddenly rises.
Due to the "self-tightening seal" characteristics of the sealing ring and the ideal contact stress parabolic distribution characteristics, it has the ability to adapt to medium pressure changes and good sealing performance, so it is widely used in mechanical seals.