Special considerations for O-rings in dynamic applications

In dynamic applications, the design and use of O-rings require special considerations to ensure that they can maintain the sealing effect for a long time during the movement. Here are some key special considerations:

1. Friction

In dynamic applications, O-rings are subject to constant friction, especially in situations of reciprocating, rotating or spiral motion. Excessive friction may cause wear, overheating or deformation of the O-ring, which in turn affects the sealing performance. Therefore, it is necessary to select materials with low friction coefficients (such as fluororubber, PTFE coating, etc.), or add lubricants to reduce friction.

2. Wear resistance of materials

In dynamic applications, O-rings often come into contact with moving surfaces and are prone to failure due to wear. Therefore, o ring materials with good wear resistance (such as fluororubber or polyurethane) are more suitable for dynamic sealing. At the same time, ensure that the surface of the O-ring is smooth and flat to reduce wear.

3. Selection of hardness

In dynamic applications, the hardness of the O-ring has an important impact on its sealing effect and durability. Generally, O-rings with a hardness of 70-90 Shore A are suitable for dynamic applications to ensure that they have sufficient elasticity to seal and can resist the pressure caused by movement.

4. Compression set

Under repeated motion, the O-ring is compressed and released cyclically. The material's resistance to compression set is important to prevent the O-ring from losing its resilience after long-term use. Selecting materials with low compression set (such as silicone rubber, fluororubber, etc.) can increase the life of the seal.

5. Effect of temperature

In dynamic applications, the temperature may rise with the heat generated by friction, affecting the material properties of the O-ring. Therefore, high-temperature resistant materials (such as fluororubber, silicone rubber, etc.) need to be selected to ensure that the sealing performance can be maintained at high temperatures.

6. Pressure shock

In dynamic applications, rapid changes or shocks in pressure may occur, which can easily cause damage to the O-ring. To avoid this, an O-ring structure with a retaining ring or an enhanced sealing material can be selected to improve the pressure resistance.

7. Lubrication

In dynamic applications, proper lubrication can reduce friction, wear and heat, thereby extending the life of the O-ring. The choice of lubricant must be compatible with the O-ring material to avoid swelling or failure of the material.

Through the above special considerations, the life of the O-ring in dynamic applications can be effectively extended and its sealing performance can be improved.