Physical and mechanical properties of O-ring seals

O-ring is a common sealing element, widely used in a variety of static and dynamic sealing applications. For example, in hydraulic systems, rubber O-rings can be used to seal the gap between the piston rod and the hydraulic cylinder, thereby preventing the leakage of hydraulic oil. In order to better understand the performance of rubber O-ring, this article will introduce its physical and mechanical properties in detail.

First, raw materials and structure

Rubber O-rings are usually made of natural rubber, synthetic rubber or silicone rubber. Its basic structure is a circular cross-section, wherein the empty circular cross-section can be used to fill the medium, while the outer circle is closely fitted with the mating surface, so as to achieve the sealing effect.

Physical and mechanical properties

1. Sealing performance

The rubber O-ring has excellent sealing performance. Its sealing principle is mainly based on the compression rebound effect, that is, when the rubber O-ring is compressed by external force, the rubber material inside will deform, fill the gap and produce a sealing effect.

2. Dielectric resistance

Rubber O-ring can be applied to a variety of media, such as hydraulic oil, lubricating oil, gas and so on. Its medium resistance depends on the properties of rubber materials, such as acid resistance, alkali resistance, oil resistance, etc. Selecting the appropriate rubber material can make the rubber O-ring maintain good sealing performance in the specific medium.

3. Temperature adaptability

The rubber O-ring can be used in a certain temperature range. Its temperature adaptability depends on the thermal properties of the rubber material, such as glass transition temperature and softening point. The selection of rubber materials with good temperature adaptability can make the rubber O-ring maintain good sealing performance in different temperature environments.

4. Wear resistance

The rubber O-ring will cause friction with the mating surface during use. Good wear resistance can extend the service life of the rubber O-ring, reduce the frequency of replacement, and thus reduce maintenance costs.

5. Anti-aging performance

Rubber O-ring in the long-term use of the process will be affected by oxygen, ultraviolet and ozone and other environmental factors, aging phenomenon. The rubber material with good anti-aging performance can extend the service life of the rubber O-ring and improve the stability of the sealing performance.

2. Application examples

In hydraulic systems, rubber O-rings are often used to seal piston rods. Here is an application example:

In a hydraulic pump station, the movement of piston rod needs to realize the sealing of hydraulic oil. In order to prevent leakage of hydraulic oil, rubber O-ring is used to seal the piston rod. The specific implementation method is: the rubber O-type sealing ring is installed on the outer circle of the piston rod, so that its section is closely fitted with the surface of the piston rod. When the piston rod moves, the rubber O-ring is compressed, producing a rebound effect, filling the gap between the piston rod and the hydraulic cylinder, so as to achieve the sealing effect.

As a common sealing element, rubber O-ring plays an important role in a variety of static and dynamic sealing occasions. Its excellent physical and mechanical properties, such as sealing performance, medium resistance, temperature adaptability, wear resistance and aging resistance, make it have good adaptability in different application scenarios.