What is the sealing principle of rubber O-ring?

The sealing principle of rubber O-ring is mainly based on its elastic deformation and contact pressure. The following is a detailed explanation of the sealing principle of rubber O-ring:
1, Overview of Sealing Principle
Rubber O-ring is a typical extrusion type sealing element. The implementation of its sealing performance depends on the initial compression deformation generated by the O-ring during installation, as well as the contact pressure formed under system pressure. When the contact pressure is greater than the internal pressure of the sealed medium, leakage can be effectively prevented.
2, Detailed explanation of sealing principle
Initial compression deformation:
When installing rubber O-rings, it is necessary to generate a certain initial compression deformation in the radial or axial direction. This deformation determines the initial sealing ability of the O-ring.
The size of the initial compression deformation can be achieved by adjusting the fit tolerance between the O-ring and the groove.
Formation of contact pressure:
When the system pressure acts on the O-ring, it will undergo further elastic deformation, thereby forming contact pressure on the sealing contact surface.
The magnitude of contact pressure is related to factors such as the material, hardness, size, and system pressure of the O-ring.
Implementation of sealing effect:
If the contact pressure is greater than the internal pressure of the sealed medium, the O-ring can effectively prevent medium leakage.
When the system pressure increases, the contact pressure of the O-ring will also increase accordingly, thereby enhancing the sealing effect.
3, Factors affecting sealing performance
Material and hardness of O-ring:
O-rings of different materials and hardness have different elasticity and wear resistance, which affects their sealing performance.
For example, O-rings made of high-performance materials such as fluorine glue have better heat resistance, oil resistance, and corrosion resistance.
Dimensions and tolerances of O-rings:
The size and tolerance of O-rings have a significant impact on their sealing performance.
Sizes that are too large or too small, as well as tolerances that are too large, may result in poor sealing performance.
The shape and size of the groove:
The shape and size of the groove also have a significant impact on the sealing performance of the O-ring.
The depth, width, and chamfer parameters of the groove need to match the size of the O-ring.
Installation quality:
The installation quality of O-ring directly affects its sealing performance.
During installation, avoid scratching, twisting, and misalignment to ensure that the O-ring can function correctly.
Work environment:
Factors such as temperature, pressure, and chemical media in the work environment can also affect the sealing performance of O-rings.
For example, high temperature and high pressure environments may cause aging, deformation, or failure of O-ring materials.
The sealing principle of rubber O-ring is based on its elastic deformation and contact pressure. To ensure its sealing performance, it is necessary to choose the appropriate O-ring material, hardness, size, and tolerance, and pay attention to factors such as the shape and size of the groove and installation quality.