Research On The Friction Performance Of Thin-walled Flexible Bearing Rings Based On Intensified Grinding And Ultra-precision

Thin-walled flexible bearings are a kind of bearings commonly used in industrial robots.They often endure periodic alternating stress during use.The friction and wear caused by the relative sliding of rollers and raceways is one of the main failure forms of thin-walled flexible bearings.In view of this situation,the thin-walled flexible bearing is the research object in this paper,and the main research purpose is to reduce bearing wear.Strengthening function of bearing ring raceway surface based on strengthening grinding-superfinishing,through theoretical analysis,simulation modeling analysis,and experiment The combination of the three methods was used to study the friction performance of thin-walled flexible bearing rings after strengthened grinding-superfinishing.Firstly,the theoretical analysis of the strengthened grinding-superfinishing was carried out,and the theoretical model of the collision between the single steel ball-grinding powder and the workpiece was established,and the theoretical relationship between the strengthened grinding process parameters,the superfinishing amount and the oil film thickness and pressure during bearing operation was obtained.Based on the secondary development of Abaqus / Python,a three-dimensional random collision model of reinforced grinding was established,and the superfine treatment of the reinforced surface was carried out using data screening methods.Finally,based on the surface morphology of the material after the strengthened grinding-superfinishing simulation calculation,Based on Fortran for fluid dynamic pressure lubrication simulation,oil film thickness and pressure distribution under different process parameters.strengthened grinding,superfinishing,and friction and wear tests were carried out on thin-walled bearing rings in sequence,and the surface roughness,microhardness,surface morphology,friction and wear of the surface of the bearing ring raceway after strengthened grinding and superfinishing To conduct research.The main conclusions are as follows:(1)With the increase of the strengthening grinding time,the surface roughness of the ferrule raceway first rises and then decreases and then remains stable.The super-finish treatment can significantly reduce the roughness.The surface roughness of the superfinish 3s sample decreases from 0.81 ± 0.09μm to 0.29 ± 0.04μm,continue to increase the superfinishing time,the sample roughness will fluctuate up and down at 0.28μm.(2)With the increase of the depth,the hardness of the ferrule raceway withstrengthened grinding-superfinishing treatment gradually decreased from 780-800 HV to 710.3 ± 1.2HV.With the increase of the grinding time,the surface hardness and the depth of the hardened layer also Increased,but after 15 minutes of strengthened grinding time,the change in the depth of the hardened layer is not obvious,basically maintained between 90-100μm.Superfinishing will reduce the thickness of the hardened layer of the raceway.With the increase of superfinishing time,the hardened layer formed by the final strengthening grinding will be covered by superfinishing.(3)Strengthened grinding-the surface of the raceway after the super-precision treatment still retains the micro-pits produced by the strengthened grinding process,and with the increase of the grinding time,the number of remaining pits first increases and then decreases,after the super-finish treatment The surface becomes noticeably flat,but some pits are still retained.With the increase of superfinishing time,the number of remaining pits is getting less and less,and the existence of pits can not be seen on the surface of the ferrule raceway of superfinishing time 12 s and 15 s.(4)Strengthened grinding-super-finishing can reduce the friction coefficient and wear of the bearing raceway surface,but after the strengthened grinding time exceeds 15 min,the surface of the raceway reinforcement layer tends to saturate,and the friction coefficient and the amount of wear do not change significantly;super finishing The amount of wear reaches the minimum between 3-9s,but the superfinishing time is further improved,and the micro-textures that are beneficial to lubricating grinding are gradually removed.At this time,the amount of wear is increasing.When the final micro-textures are completely removed,the wear The volume tends to be stable.