Research On The Profile Modification Of Cylindrical Roller Bearing Based On PMWR Method

The bearings are indispensable parts of mechanical contact field,its life and performance directly determines the whole life and efficiency.The main reason for the failure of bearings is the unreasonable contact pressure distribution in the contact area.The contact area between the bearing roller and the raceway is properly reconstructed,which can re-distribute the pressure in the roller contact area.Therefore,how to determine a reasonable roller modification curve is the key to solve the uneven distribution of bearing contact pressure and reduce the peak value of contact pressure.Starting from the general law of mechanical nature and contact problems,a method of Profile Modification Without Re-analysis based on the optimal contact pressure distribution is put forward,or “PMWR ” method for short.Taking the PMWR method as the modification theory,we explore new ideas and methods suitable for cylindrical roller bearing modification.(1)The PMWR modification method is put forward which can make the contact pressure distribution reach the best state on the contact surface,and we describe the modification process detailedly.In addition,two optimization models for PMWR method are put forward to ensuring the best distribution of contact pressure.A new solution is proposed to solve the problem of the non-definite solution to the modification value under the condition of uniform load and partial load,which eliminates the rotation problem of the modification amount and makes the modification value unique.(2)The profile of single roller is modified by the PMWR method,we verify the rationality and effectiveness of the PMWR method used in roller repair.The modified results of PMWR method are compared with the modified results of the two kinds of Lundberg logarithmic curves under uniform load and partial load conditions respectively,highlighting the advantages of the PMWR method.(3)The modification method of multi-column nodes of single-roll considering circumferential axial coupling effect is proposed,which solves the problem that the load transfers between the contact nodes in the circumferential columns due to multiple columns contact.And according to the positions of the contact nodes in each column,the coordinate corrections of the modification value of the nodes are proposed to make the modification result more accurate.(4)The theoretical calculation method of the normal contact force of the loaded maximum roller in a bearing is proposed.Taking the maximum loaded roller as a modification object,and reducing the maximum contact pressure generated by the maximum loaded roller as the modification target,the modification program of "initial analysis of the bearing assembly-the single roller prerepair-the multi roller modification" is put forward.And through numerical case analysis,it is proved that this scheme can effectively reduce the contact pressure peak of the bearing assembly,eliminate the “edge effect” of the roller at each position,and greatly increase the bearing life.