The influence of hydraulic oil on the seals and methods

Second, the sealing oil resistant material ( Liquid) Performance evaluation: the seal oil resistant rubber materials ( Liquid) Performance, generally adopt standard test oil, according to the test temperature conditions prescribed by the standard and test the steeping time, by means of immersion test values before and after contrast ( Changes such as material hardness, tensile strength, rate, breaking elongation rate of change, volume change rate, compression permanent deformation, etc. ) And evaluate its performance. No standard oil is 'low volume increase oil & quot; , the composition of the mixture of mineral oil by solvent extraction, chemical processing, dewaxing wax particles and neutral oil; No3 - standard oil is a 'high volume increased oil & quot; By the selected naphthenic crude product, vacuum distillation to obtain two kinds of lubricating oil compositions. Different USES is not the same as the assessment of material parameter values. Third, the hydraulic oil ( Liquid) Affect the performance of the seals, seal theory is that: in a dynamic flexible seal and its matching surface between a complete layer of lubrication film. In normal state, it is through this layer of lubricant to achieve sealing and extend the life of the seal. In the hydraulic system, hydraulic oil, Liquid) Affect the performance of packing seal in addition to the medium/intermiscibility of sealing material, oil viscosity, viscosity changes with temperature, reciprocating ( Rotation) Movement velocity, pressure and shaft or the material of the piston rod, cylinder, hardness, geometric shapes, surface finish, and the structure of seal factors that influence the lubricating film formation and film characteristics influence the sealing effect. Generally speaking, form continuous lubrication film can obtain ideal sealing effect. Japan NOK company the first in the world using the latest image processing technology to explain the seal principle of oil seal. Think oil seal ( Rotary dynamic seal) The sealing mechanism by lubricating property and sealing principle of two parts. Lubrication characteristics: the oil seal of the friction characteristics controlled by the fluid viscosity and sliding speed, the relative sliding surface oil seal on the shaft in the oil film lubrication condition, so keep small friction resistance, wear small. Sealing principle: oil seal sliding contact surface oil flow from the air side flow to the oil side and from the oil side flow to the atmospheric side of the cycle. Good lubricating sliding surface, which can prevent wear and tear, no leakage. When the system is high speed, the impact of the formation of a continuous lubrication film, increase the friction heat, is beyond the scope of sealing material heat resistance, causes the damage of the seals. When the pressure is too large, in addition to influence the formation of oil film, will also produce rubber and plastic seal 'squeeze gap & quot; Role, generally can be used with 'ring & quot; To improve. Or choose small friction coefficient and good self-lubrication PTFE composite seal structure will help to improve the lubrication between the friction pair, suitable for high speed reciprocating motion and high-pressure system of oil cylinder piston and piston rod seal. According to the working conditions of system and medium environment reasonably selects the seals and sealing materials, correct installation and maintenance of the seals, is to obtain effective sealing effect, reliability and service life of the key.