Research On Contact Characteristics Between Oilstones And Rollers In Through-feed Superfinishing Of Taper Rollers

The rolling bearing is an important basic part in industrial production and daily life.Tapered roller bearings are widely used.Generatrix of the tapered roller is a convex curve which,if appropriate,can improve carrying capacity,reduce edge stress concentration and improve elasto-hydrodynamic lubrication.Theories and experiments have proven that logarithmic crown is the best one.In the whole process of tapered roller machining,through-feed superfinishing is the last one which plays a decisive role in keeping quality of tapered rollers.Through-feed superfinishing is not yet mature because of complex and tiny shape of crown.Based on features of through-feed superfinishing of taper rollers,this paper regard the taper roller as a cone which is consisted of many cylindrical slices whose diameters increase in turn.Modeling methods of grinding principle are applied and contact feathers between oilstones and tapered rollers are analyzed.Circumferential contact arc length,dynamic valid edge number,un-deformed chip max thickness of cutting edge and cone roughness of fixed attitude through-feed superfinishing are modeled and analyzed by MATLAB.Change rules of contact line and process of material removal of variable attitude through-feed superfinishing are analyzed.The experiment of through-feed superfinishing of taper rollers is finished.Cone roughness values are obtained by experiments and be contrasted with theory values.Some conclusions are obtained as follows.Circumference contact arc length increases with the increase of cylindrical slice radius.Dynamic valid cutting edge number increases with the increase of cutting surface depth of oilstones as well as cylindrical slice radius.Un-deformed chip max thickness increases with the increase of rotating speed and of cutting surface depth of oilstones as well as cylindrical slice radius but with the decrease of oscillation frequency of oilstones and sharpness of cutting edge.Something happen simultaneously when the small end of a tapper roller rises: the length of the contact line between an oilstone and a small end of a taper roller increases,the distance of two contact lines between an oilstone and a cone of a taper roller increases,the length of two contact lines between an oilstone and a big end of a taper roller decreases.The variable attitude through-feed superfinishing which can machine any kind of crown shape theoretically is proved to be the best process.Cone roughness of taper rollersdecreases with the increase of oscillation frequency of oilstones.Roughness data of experiment is similar to that of theory.In this paper,the contact characteristics between oilstones and taper rollers in through-feed superfinishing are studied in detail.These conclusions provide an important theory support for revealing the correcting mechanism and processing regularity of taper roller crown.