Do You Know The Six Factors That Affect The Sealing Performance Of The Sealing Ring?

When the working speed of the seal ring is very low (<0.03m>0.8m/s), the lubricating oil film may be destroyed, and the oil seal is not well lubricated and frictions heat, resulting in greatly reduced life!
1. Speed of movement
It is recommended that polyurethane or rubber and plastic oil seal work in the speed range of 0.03m/s~0.8a/s
Step 2: Temperature
Low temperature will reduce the elasticity of the polyurethane or rubber seal, resulting in slippery dew, and even the whole oil seal becomes hard and brittle. High temperature will make the oil seal volume expand and become soft, resulting in the oil seal friction resistance increases rapidly and the oil seal pressure capacity decreases. It is recommended that the continuous operating temperature of polyurethane or rubber seal is -10℃ to +80°C.
3. Work stress
The oil seal has the minimum starting service pressure (minimun service pressure), and the low pressure T should be used as the oil seal with low friction performance and small starting resistance. Below 2.5WPa, polyurethane oil seal is not suitable: high pressure to consider the oil seal pressure deformation, need to use anti-extrusion stop ring, grooving processing also has special requirements
In addition, different materials of oil seals have different optimal working pressure ranges. The best working pressure range for polyurethane oil seals is 2.5~31.5a
4. Working medium
In addition to selecting T as a medium in strict accordance with the manufacturer's recommendations, it is important to keep the working medium clean. Aging or pollution of the oil will not only cause the components in the system to fail, accelerate the aging and friction of the oil seal, but also the dirt in it may scratch or embed the oil seal, making the sealing ring ineffective. Therefore, it is necessary to regularly check the quality of the oil and its cleanliness, and replace the oil filter or oil according to the maintenance specifications of the equipment. The air remaining in the oil in the cylinder will be compressed by high pressure, which will cause the oil seal to burn out and even fully carbonized. In order to avoid this situation, exhaust treatment should be carried out at the initial operation of the hydraulic system. The hydraulic cylinder should also run at low pressure and slow speed for a few minutes to confirm that the residual air in the oil has been drained before it can work normally.
5 Lateral load
The piston must generally be equipped with a supporting ring to ensure that the cylinder can withstand a larger load. Seals and support rings play completely different roles, seals have different roles, seals can not replace the support ring load. Hydraulic cylinders with lateral forces must be supported by rings with strong bearing capacity (metal rings can be used when heavy loads are loaded) to prevent oil from working under eccentric conditions and causing leakage and abnormal wear.
6. Hydraulic shock
There are many factors of impact if the excavator scoop suddenly hits the stone. The moment a crane lifts or drops a heavy object. In addition to the factors, for high pressure large flow hydraulic systems,
When the actuator (hydraulic cylinder or hydraulic motor, etc.) is reversing, if the reversing valve performance is not very good, it is easy to produce hydraulic shock. The instantaneous high pressure generated by the hydraulic shock may be several times the working pressure of the system, and such a high pressure will tear the oil seal or locally squeeze it into the gap in a very short time, causing serious damage. Generally, the cylinder with hydraulic impact should be installed on the piston rod with a buffer ring and a stop ring. The buffer ring is installed in front of the oil seal to absorb most of the impact pressure, and the stop ring prevents the oil seal from squeezing into the gap under high pressure and the root from being bitten.