Investigation On Contact Characteristics Of Thin-Wall Angular Contact Ball Bearings For Robots

As an irreplaceable important equipment in advanced manufacturing industry,industrial robot is one of the important indexes to measure the level and the content of science and technologyof manufacturing industry.As the core part of the robot,the thinwall angular contact ball bearing must satisfy the requirements of the robot,such as thin wall,high bearing capacity,high precision,low friction torque,light weight and so on.The classical theory of Rolling bearings are all based on the rigid ring hypothesis and calculation does not take into account the deformation of the ring.But it has a relatively big error for thin-wall bearings which have flexible supported rings.This paper focuses on theThin-Wall Angular Contact Ball Bearings ZR76/82 C for Robots.The static and dynamic contact characteristics are analyzedwith the help of ABAQUS finite element softwareand the static contact deformation test and dynamic performance test are carried out.Optimizationdesignconsidering the contact stiffness ofthe thin-wall angular contact ball bearing ismade by RomaxCLOUD.Inthe RomaxDesigner system modeling and analysis software,the influence of different supporting methods on the bearing contact characteristics is studied.The results of this study can provide reference for the analysis and calculation,structural design and the shafting design of the thin-wall bearings.The staticfinite element model for thin-wall angular contact ball bearing ZR76/82 C is established.The deformation of the ring and the influence of the thickness of the ring on the deformation under the flexible constraints is analyzed.Those are compared with the situation under the rigid constraints.The static contact deformation test of the bearing are carried out on the bearing static test device developed by the research group.The axial displacement and radial deformation of the bearing under axial load are measured.The correctness of the finite element model is verified.The dynamic finite element model is established.Boundary conditions are realized bythe distribution coupling settingsunder thethe flexible ring.The velocity,displacement,acceleration,friction moment and mises of bearing under different working conditions are analyzed.The vibration and friction moment of bearing under different working conditions are tested by using bearing dynamic performance tester.Failure bearings are Failure analysed by confocal laser scanning microscope.Optimization design considering the contact stiffnessof the thin-wall angular contact ball bearing is made by RomaxCLOUD.A multi-object optimal design is put forward and a mathematical model is set up,which is expected offers the design with bigger contact stiffness,minimum oil film thickness and longger life.The contact stiffness simulation analysis of the optimized bearing is carried out.The calculation results of RomaxCLOUD are compared with the finite element solution.Rigid ring and flexible ring bearing assembly model are established by the RomaxDesigner system modeling and analysis software.The difference of displacement,shape deviation and load distribution between rigid and flexible models are analyzed.Flexible ring bearing assembly model supported bysolid shaft and hollowshaft with different aperture are established.The effect of support modeon the contact characteristics of bearing,such as displacement,deformation andload distributionare obtained.