Guide Roller's Ideal Surface And Its Driving Characteristics In Through-feed Superfinishing Of Tapered Rollers

Tapered roller is a kind of important rolling element in rolling bearing.Throughfeed superfinishing is the major finishing process of tapered roller's rolling surface.In this process,the rollers is supported by two guide rollers to ensure its posture,and are driven by the guide rollers to achieve its through-feed and rotation.The geometrical shape of the guide roller has an important influence on the crown and surface quality of ground roller by affecting the roller's posture and motion stability.There are slipping between the guide rollers and rollers in the process.The slipping affects the service life of guide roller because of the wear of guide roller's surface,what's more,it affects the superfinishing efficiency and quality by causing the roller's rotation speed to change.Therefore,it is of great theoretical significance and good application value to study the ideal shape of guide roller and its driving characteristics on roller in through-feed superfinishing of tapered rollers.The fixed posture through-feed superfinishing is an important way in through-feed superfinishing of tapered rollers.In this paper,the guide roller' ideal profile characteristics and its driving characteristics on roller in fixed posture through-feed superfinishing are studied.The main research contents and conclusions are as follows:(1)The ideal profile equation of guide roller in fixed posture through-feed superfinishing is established and characteristics of guide roller's ideal profile are analyzed.The ideal profile equation of guide roller is established according to the conjugate surface principle based on the analysis of the geometrical and relative motion relation between the guide roller and roller.The characteristics of guide roller's ideal profile are analyzed by numerical examples because the ideal profile equation is a complicated mathematical expression which can not be analyzed analyticaly.The results show that the axial section shape of guide roller is slightly concave and inclined.The inclined angle of the axial section shape of the front guide roller is greater than that of the rear guide roller,and the degree of concave is less than that of the rear guide roller when the roller's posture is oblique.The inclined angle and concave degree of axial section shape of the front guide is same as that of rear guide roller when the roller's posture is alignment.(2)The characteristics of the guide rollers driving roller are studied.The compute method of relative sliding speed between the guide roller and the roller is established.And their characteristics are analyzed by analyzing the contact geometric relation and relative motion relation,as well as the static equilibrium relation between the guide roller and the roller under stable working conditions.The results show that:(1)In the relative sliding between the guide roller and the roller,axial sliding speed is equal to the through-feed speed of roller,while the circumferential sliding speed distribute unevenly along the contact line between the guide roller and the roller,and its distribution curve is an oblique line.(2)There is a corresponding critical value of roller's half cone angle under certain working condition.When the roller's half cone angle is less than the critical value,the direction of circumferential relative sliding velocity of each point on the contact line is consistent,and its value is not zero.It is in a circumferential overall slipping state between the guide roller and the roller.When the roller's half cone angle is larger than the critical value,there is a circumferential pure rolling point on the contact line.Both sides of the pure rolling point are in a circumferential sliding state,but the sliding speed are in the opposite direction.When the roller's half cone angle is equal to the critical value,there is a circumferential pure rolling point,which is located at the large end of roller.(3)The larger the roller's half cone angle is,the more uneven the sliding on the contact line is,the greater the degree of sliding is,the more easily the guide roller wears,in addition,the smaller the roller's rotation speed is,the lower the superfinishing efficiency is.But there is no significant influence on superfinishing efficiency because of the change of roller's rotation speed is not big in the vast majority of tapered roller's cone angle range(half cone angle is less than 5°).