Research On Materials And Structure Optimization Of Acrylic Rubber Oil Seal With High Wear-resistant Performance

Rotary shaft lip seal namely oil seal is a key basic component to prevent the leakage of lubricating medium in rotating parts.It is widely used in construction machinery,automobile,industrial pump and gas turbine.The material and structure parameters of oil seal have important influence on its wear resistance and sealing performance.At present,The oil seal material used in automobile transmission is mainly fluorine rubber,but with the emergence of new synthetic additives,The oil seal products made of fluorine rubber failed prematurely due to its swelling,and acrylic rubber?ACM?can endure this kind of medium,but the existing problem of poor wear resistance of ACM rubber material makes its application of rotary shaft lip seal restricted due to premature failure.Therefore,we intends to start with material and structural parameters optimization of ACM oil seal in this paper.Firstly,the influence of fiber-shaped fillers and its combination with solid self-lubricant on the properties of acrylic rubber composite was discussed.Based on this,the effect of surface modification of fiber-shaped filler on the friction and wear performance of acrylic rubber composite was also investigated.Secondly,based on the oil seal products manufactured using self-made wear resistant rubber composite,the finite element analysis software was used to simulate and analyze the contact state of oil seals with different structural parameters,and the influence of structural parameters on the wear behavior of oil seals was investigated through experimental tests.The main research contents and results are as follows:?1?The addition of fiber filler can significantly improve the friction and wear performance of ACM vulcanizates,of which the acular wollastonite modified vulcanizates have the best friction performance.With the increase of acular wollastonite,the friction coefficient of modified ACM vulcanizate decreased gradually,while the volume wear decreased firstly and then increased.When the acicular wollastonite content was 35phr,the friction coefficient of the vulcanized rubber was 0.445,and the wear volume decrease to 1.77mm³ from 7.15mm3.Compared with low load condition of 25 N,the friction coefficient of vulcanized rubber decreased as a whole under high load condition of 50N.The characteristics of unmodified ACM vulcanized rubber are adhesive wear and dual plough wear.The addition of fiber fillers gradually changed the wear characteristics of vulcanized rubber into fiber pull-out and abrasive wear,which effectively inhibited the adhesive wear of the worn surface,and appeared the characteristic transverse ridgeline markings of rubber material,and the worn surface was smooth and level.When high load is added,some wear signs of vulcanized rubber change from abrasive wear to adhesive wear.?2?The friction performance of micron MoS₂ and polyphenyl ester modified ACM/wollastonite vulcanized rubber was improved,among which the effect of micron MoS₂modified sample was better.the friction coefficient of 6 phr micron MoS₂ modified sample was 5.2%lower than that of ACM/wollastonite vulcanized sample,and the wear volume was6.2%lower.At this time,The matrix load is borne by acicular wollastonite and micron MoS₂.micron MoS₂ can play a good lubrication effect.The wear characteristics are adhesive wear and slight abrasive wear.Change micron MoS₂ to nanometer MoS₂ to modify the vulcanized rubber.When the amount of nano MoS₂ was 1 phr,the friction coefficient of the vulcanized rubber sample reached the lowest point of 0.4 lower than that of the micron MoS₂ modified sample.KH560 was used for chemical modification of acicular wollastonite,and infrared spectrometer was used to verify the modification effect of KH560 on acicular wollastonite.Although the friction coefficient of the modified samples did not change significantly,the wear amount further decreased by 9.7%.At this time,acicular wollastonite is more evenly mixed and more difficult to extract from the ACM matrix.Optical image measurement instrument showed that the transfer film of KH560 modified vulcanized adhesive was uniform and dense.?3?The radial force obtained by finite element analysis is in agreement with the measured radial force.With the increase of interference,the pumping rate,radial force and contact width of seals also increase at the same time,and the overall contact pressure rises,which is conducive to preventing the leakage of lubricating oil.Among them,the maximum contact pressure first rises and then slightly decreases.And because seals only need a small axial force can prevent the leakage of lubricating oil;In addition,the greater the axial force,the greater the friction between the lip and the axis of rotation.Therefore,the comprehensive performance of the seal is better when the interference is 1 mm.When the stiffness of the spring increases,the contact pressure of the seal increases,but the pumping rate first increases and then decreases slightly.The increase of stiffness coefficient is beneficial to prevent the leakage of lubricating oil and also increase the wear of the main lip.When the stiffness coefficient is 1.4n/mm,the comprehensive performance of seals is better.The increase of R value of seals will reduce the radial force of the main lip,increase the contact width of the main lip,and promote the uniform distribution of contact pressure,thus reducing wear.Considering that R value is too large,too small radial force will easily lead to early leakage of seals.Therefore,when R value is 0.4mm,the sealing performance and wear resistance of the oil seal main lip are better.