Study On Lubrication Characteristics Of Air Splicer Of Automatic Winder

The air splicer is a kind of precise mechanical equipment and one of the core components of the automatic winder.Its main transmission form is cam transmission.At present,the manufacturing technology of the high-end air splicer is mainly in the hands of a few foreign countries.In order to break through the technical restrictions,to improve the lubrication characteristics of the air splicer and to improve the working stability and service life,the lubrication characteristics of the air splicer of the automatic winder were studied in this paper.In this paper,the transition curve form of air splicer cam was studied.Based on different calculation conditions such as isothermal,thermal EHL and rough surface,the corresponding EHL lubrication models of steel roller rolling over the transition curve were established.The established models were solved by the corresponding numerical methods such as multigrid method and multigrid integration method,and the lubrication effects under different operating parameters were explored,and the isothermal EHL calculation results were verified by experiments.The main research contents are as follows:（1）In this paper,the background of the research on the lubrication characteristics of the air splicer of the automatic winder,the research status of the EHL and its solution numerical method,the calculation method of the mixed lubrication and the EHL experiment at home and abroad were described,and the research purpose of the paper was put forward,and the research contents of the paper were summarized.（2）The method of expansion was used,the coordinate system of transition curve was established,the equations of arc transition curve,parabola transition curve and polynomial transition curve of 4th and 5th degree were derived,and the effects of cam radius R₀,motion s and transition angle?on the displacement,velocity and acceleration of transition curves were explored.The results show that:The arc transition curve and parabola transition curve will inevitably cause flexible impact at the end of the transition curve.Reducing the cam radius R₀,or increasing the motion s or increasing the transition angle?is conducive to reducing the acceleration of the arc transition curve and parabola transition curve.By designing reasonable parameters,the 4th and 5th degree polynomial transition curve can avoid the flexible impact at the end of the transition curve.（3）The EHL model that the steel roller rolls the transition curve of the cam was established.The equations of the transition curve,the motion equations of the steel roller and the EHL equations were combined to form a control equation group,and the EHL equations were dimensionless and discrete.The multigrid method was used to solve the problem,and the influences of different parameters on the EHL film of the isotherm contact were explored.The results show that the increasing of viscosity increases the accumulation of lubricating oil at the outlet and decreases the increasing speed of the minimum film thickness,and increases the increasing speed of the secondary pressure peak.When the comprehensive radius of curvature increases,the oil film load per unit area in the contact area decreases,the overall pressure of lubricating oil film decreases,and the film thickness increases gradually.When the entrainment speed increases,the speed of the secondary pressure peak increase is greater than that of central pressure,the increase speed of the minimum film thickness is lower than that of the central film thickness.When the load increases,the film thickness decreases,the central pressure increases,the contact area increases,and the minimum film thickness and the secondary pressure peak move toward the outlet.（4）The EHL model that the steel roller rolls the transition curve of the cam was solved by the multigrid method based on the two calculation conditions of isothermal and thermal EHL.The step-by-step scanning method was used to calculate the oil film temperature,and the effects of several operating parameters on the lubrication characteristics were explored respectively.The results show that under the same increment of a certain parameter,the increment of film thickness under the condition of thermal EHL calculation is lower than that under the condition of isothermal EHL calculation;the proper increase of cam radius R₀,rotating speed n,lubricant viscosity₀ or steel roller radius R₁ is conducive to the improvement of lubrication condition;the increase of motion s or transition angleθis unfavorable to the improvement of lubrication condition.（5）The mixed lubrication model of the steel roller rolls through the rough surface of cam transition was established.The load sharing principle and numerical solution were used to solve the model.The calculation method and results were verified,and the influences of various working condition parameters on the mixed lubrication characteristics were explored.The results show that the proper increase of cam radius R₀,rotating speed n,lubricant viscosity₀ or steel roller radius R₁ is beneficial to the improvement of lubrication condition,the increase of motion s or transition angle?is not conducive to the improvement of mixed lubrication.（6）Based on the optical interference method,the experiment was carried out by using the EHL film measuring instrument,and the numerical calculation results of isotherm EHL of line contact were verified and explored.The results show that:the results of film thickness measured by the experiment are in good agreement with the numerical calculation results;the experimental values of the minimum film thickness increase with the increase of the entrainment speed,but the increase degree tends to slow down;the experimental values of the minimum film thickness decrease with the increase of the load,and the relative error between the numerical calculation values and the experimental measurement values increases with the increase of the load.