Effect of hydraulic oil on seals

The hydraulic oil guide is the hydraulic medium used by the hydraulic system using the hydraulic pressure energy, which plays the role of energy transmission, system lubrication, corrosion prevention, rust prevention, cooling, etc. in the hydraulic system. For hydraulic oil, the requirements for liquid viscosity of the hydraulic device at operating temperature and starting temperature shall be met first. As the viscosity change of the oil is directly related to hydraulic action, transmission efficiency and transmission accuracy, the viscosity temperature performance and shear stability of the oil shall meet various requirements for different purposes.

Thus, the role of hydraulic oil can not be ignored. What effect will the hydraulic oil have on the Seal performance? Here is a brief analysis:
No matter which material, it shall have the following properties:
1. Have certain mechanical and physical properties, such as tensile strength, constant elongation strength and elongation;
2. It has certain elasticity, appropriate hardness, and small compression deformation;
3. It is suitable for the working medium and is not easy to swell, decompose and harden;
4. Wear resistance and tear resistance;

5. It has high temperature and low temperature aging resistance.

None of the above mentioned properties of Sealing materials have these properties. It is necessary to select appropriate sealing materials according to the working environment, such as temperature, pressure, medium and motion mode, and meet certain requirements by formulating the matching formula of materials. Or more than two kinds of composite or composite structures can be used to give play to their respective advantages to achieve a more comprehensive effect.

Factors affecting sealing effect: selection of sealing structure, oil film formation, pressure, temperature, material compatibility, material, hardness, geometric shape, surface finish, etc. of the working surface contacted by the dynamic seal.

Compatibility of sealing material and hydraulic oil (fluid)

One of the sources of particle pollution of hydraulic oil is the "debris" or "wear debris" caused by the incompatibility between the seal material and the hydraulic oil. The "debris" caused by the damage of the seal due to the "swelling" or the "extraction" of the unconsolidated inorganic substances and filling reinforcement materials make the seal damaged and ineffective. At the same time, the pollution of the oil causes the hydraulic oil to deteriorate and become ineffective.

Formation of sealing effect: dynamic seal is divided into non-contact seal and contact seal. Non contact seals are mainly various mechanical seals, such as graphite packing rings, floating ring seals, etc; Both rubber and plastic composite seals and rubber and plastic composite seals belong to contact seals. The sealing effect is obtained by blocking the leakage channel with the pre compression force filled in the sealing chamber. The seals used in hydraulic systems are mostly static seals (end face seals), reciprocating seals (piston and piston Rod seals) and Rotary Seals.