Influence of sliding surfaces on O-rings

The roughness of the sliding surface is a direct factor affecting the friction and wear of the O-ring surface. Generally speaking, the smooth surface has less friction and wear, so the roughness value of the sliding surface is often very low (Ra0.2-.050μm). However, experiments show that too low surface roughness (Ra below 0.050μm) will adversely affect friction and wear. This is because of the tiny surface irregularities that maintain the necessary lubricating oil film. It is therefore necessary to select the appropriate surface requirements. The material of the sliding surface also affects the life of the O-ring. The greater the hardness of the sliding surface material, the higher the wear resistance, the stronger the ability to maintain smoothness, and the longer the life of the O-ring. This is also an important reason for the chrome plating on the surface of the piston rod of the hydraulic cylinder. In the same way, it can be explained that the sliding surface made of copper and aluminum alloy with the same roughness has more serious friction and wear on the sealing ring than the steel sliding surface. The sealing ring with low hardness and large compression is not as good as high hardness and small compression. Amount of sealing ring durable case.