Research On Design And Machining Of The Guide Roller For Through-feed Superfinishing Of Tapered Roller

As an important part of rolling bearing, the last process in tapered roller machiningis superfinishing of the conical surface. In through-feed superfinishing of tapered roller,the guide roller plays a role in supporting, guiding and driving the rollers, and has acritical influence on accuracy and surface quality of tapered roller. This paper analyzesand researchs mainly on the design and machining of the guide roll shape and the rib insuperfinishing.1According to the spatial geometric relationship and the mutual movementsbetween the tapered roller and guide roller in superfinishing, and based on the theory ofconjugate surface, the mathematical expression of theoretical guiding face shape of theguide roller is established; The features of theoretical axial profile of the guiding faceare analyzed by numerical calculation, and the results show that the theoretical axialprofile is a slightly concave curve, the feature parameters of theoretical shape ofsuperfinishing guide roller are represented by two concepts named roll shape angle androll shape convexity, and the effect of design parameters of superfinishing guide rolleron the feature parameters is analyzed, the analysis shows that the big end radius of rollerhas a subtle influence, the big end nominal contact angle of roller has a bigger influenceespecially on roll shape angle, the half cone angle of roller has a significant influence onboth of the feature parameters,when the half cone angle of roller increases, the rollshape angel increases sharply and proportionally, the roller shape convexity has a largerincrement accordingly; Thus, some conclusions are gained: when the rollers have thesame cone angles, the lengths within the scope of guide roller spiral groove and onlydiameters with slight differences, the big end nominal contact angle of roller can beadjusted slightly so as to make the same pair of guide roller suitable for the rollers ofdifferent sizes without repetitive design and machining of superfinishing guide roller.2The spatial geometric relationship and mutual movements between grindingwheel and guide roller are analyzed, which shows that they has a similar situation with superfinishing of tapered roller, based on the theory of conjugate surface, regarding thegrinding wheel as tapered roller and making the big end nominal contact angle of rolleras0°, therefore, the mathematical expression of designed superfinishing guide rollershape is also appropriate for the grinding of guide roller. The influence of dressingparameters of grinding wheel and grinding machine adjustment parameter on the featureparameters of theoretical shape of grinding guide roller is analyzed by numericalcalculation, which shows that the dressing parameters of grinding wheel has a similarsituation with the influence of roller’s parameters on the feature parameters oftheoretical shape of superfinishing guide roller, the vertical pendulum angle of grindingwheel frame influences the grinding roll shape convexity significantly but the grindingroll shape angle commonly; based on the analysis, Selective method of the accurategrinding of superfinishing guide roller shape is proposed; numerical calculationexamples show that the grinding roller shape can be very close to the designedsuperfinishing guide roller shape by rational selections of the half cone angle ofgrinding wheel and the vertical pendulum angle of grinding wheel frame, so theaccurate grinding of the guide roller shape can be realized. Grinding experiments of theguide roller and superfinishing experiments of the tapered roller prove well in this way.3Based on the geometric and kinematic relationship as well as the friction betweentapered roller’s spherical base surface and the guider roller’s rib in through-feedsuperfinishing, ideal rib’s shape surface of the guide roller is analyzed, and its axialprofile is simplified as a straight line. the straight profile can be used as a simplifieddesign profile, and a formula for computing the incline angle of the straight profile isderived. Based on the geometric and kinematic relationships between the guider roller’srib and the grinding wheel in the rib grinding process with the special machine tool, therib’s shape surface after grinding is analyzed, and equations of the shape surface and itsaxial profile are established. The results of numerical analysis in an example show thatthe rib’s axial profile after grinding is seriously nonlinear in the root region of about0.5mm height, and is approximately linear in other region; the profile after grinding isclose to the design profile if vertical angle of the grinding wheel head is selectedproperly and the wheel crosses over the rib groove about0.5mm。...