The influence of hydraulic oil on the seals and methods

Hydraulic oil used in hydraulic transmission system as the working medium, energy transfer, conversion and control role, but also of the various components within the hydraulic system of the lubrication, anti-corrosion, rust and cooling etc. And the seal plays to prevent fluid in the hydraulic system from the joint surface between leakage, pressure maintenance, maintain energy transfer and conversion. Use most of the sealing material at home and abroad is a polymeric elastomer, some also have use of plastic and all kinds of metal under special conditions. But no matter which belongs to a kind of material, shall have the following properties: 1, has certain mechanical properties: such as tensile strength, tensile modulus, elongation 2, has certain elasticity, suitable hardness, and the compression permanent deformation; 3, to adapt themselves to the working medium, it is not easy to produce swelling, decomposition, hardening, wear-resisting, a tear resistance 5, has a high temperature resistant, low temperature aging performance. However, there is no sealing materials including all of the above performance, need according to the working environment, such as temperature, pressure, medium as well as the movement way to select the appropriate sealing material, and through developing materials with formula to meet certain requirements. Or with two or more materials composite or composite structure in the form of play to their respective special skill, achieve the result of a more comprehensive. The formation of the sealing effect: dynamic seals are divided into non-contact seal and contact seal. Non-contact seal is mainly all kinds of mechanical seal, such as: graphite packing ring, float ring seal, etc. ; Rubber and plastic composite seal and rubber seals are in contact sealing, depend on the loading in a sealed cavity, the preloading force blocking leakage channels for sealing effect. Hydraulic system is more than the sealers for static seal ( End face seal) And traverse seal ( Piston and piston rod seal) And rotating seal. Factors influencing the sealing effect: the choice of sealing structure and oil film formation, pressure, temperature, material compatibility, dynamic seal are exposed on the surface of the work material, hardness, geometric shapes, surface finish, etc. A, sealing materials and hydraulic oil ( Liquid) Compatibility: the particle pollution source of hydraulic oil is the seal material does not match with the hydraulic oil of the detrital & quot; Or 'grindings & quot; 。 Seals for 'soluble up & quot; 'Produced by the damaged elastic & quot; Or by 'extraction & quot; Out, which has not been the combination of inorganic and filling reinforcing material, make the seal damage and failure, and formed the oil pollution of hydraulic oil is so failure. Widely used in hydraulic system of vane pump, in the work pressure is greater than 6. 9 mpa, under the condition of wear and tear problems become prominent, which is used in the hydraulic oil anti-wear agent; In order to adapt to the high temperature heat source and open flame near the hydraulic system, the use of flame resistant phosphate and water Ethylene glycol hydraulic fluid, oil-in-water and water-in-oil emulsion, etc. And 'should use & quot; Of all kinds compound additive, antioxidant, antirust configuration of different USES hydraulic oil ( Liquid) A wide variety. Such as: anti-wear hydraulic oil no zinc type of compound type ( No grey type) Anti-wear hydraulic oil compound, is to use hydrocarbons sulfide, phosphate and phosphite ester, and at the same time containing sulfur, phosphorus and nitrogen S - three elements P - N extreme pressure antiwear agent. In extreme pressure industrial gear oil, also with P - S type extreme pressure agent is given priority to. Seal produce 'soluble up & quot; Or 'extraction & quot; What is the cause of the hydraulic oil additives in various chemical elements and their concentrations, on the basis of 'similar miscibility & quot; The principle of different influence on different seal material, also is not only the medium resistance of sealing material. For example: Shell Omala 320 gear oil and Shell Omala 460 gear oil displays the polarity of p ( P) Nitrile rubber element concentration at about 300 parts per million, so because of containing propylene nitrile groups and have polarity, has excellent oil resistant performance, but not suitable for this type of oil medium conditions. As the hydraulic oil ( Oil) Varieties of continuous research and development, to improve the oil ( Liquid) Performance of anti-wear and extreme pressure additives, metal attenuated agent, emulsifier and anti-foam additive, etc. , the influence of the seal material need to verify through the experiment.