| The cylindrical roller bearing with the rear fulcrum of a type of aero-engine turbine has the characteristics of high temperature,high speed,light load,while the traditional cylindrical roller bearing can no longer meet the performance requirements of the engine on the bearing.The cylindrical roller bearing in aero-engine works in the condition of light load and high speed,it often cause severe slippage during the operation of the bearings and premature failure of the cylindrical roller bearings,so the use reliability and service life have been severely challenged.It is necessary to develop a new type of main shaft bearings of aero-engine to provide reliable technical support for a type of aero-engine,which has very important theoretical and practical significance.Designing the outer raceway of the cylindrical roller bearing as a noncircular tri-lobe raceway and artificially applying a certain pretension to the non-load bearing area of the bearing,which is one of the effective methods to solve the problem of bearing slipping due to light load.At present,there are few researches on the trilobe raceway cylindrical roller bearings,and almost no theoretical research on their dynamic characteristics.In this paper,based on the characteristics of a type of cylindrical roller tri-lobe ferrule raceway,Based on the shape control technology of the raceway of the cylindrical roller three lobed wave ferrule,the X,Z,C three-axis linkage non-circular grinding scheme is put forward,and the type and function of the grinding machine are preliminarily selected.Second,A special thin-wall tri-lobe bearing mold is designed,making a special tooling suitable for this type of product for outer ring of the tri-lobe bearing whose phase angle changes.Third,Based on the Fanuc31 i system and highspeed grinding platform equipment,two sets of joint grinding programs are designed according to the curve equations of the workpiece and the grinding wheel.The parameters of wheel speed,workpiece speed,grinding margin and oscillation frequency in the grinding process were determined by the process analysis of the trilobe ferrule raceway of cylindrical roller bearing.After analyzing the influence of grinding parameters,grinding wheel and grinding fluid selection on the surface roughness of the tri-lobe bearing raceway and the influence of grinding parameters on the residual stress on raceway surface,it is concluded that CBN grinding wheel(particle size F170)and coolant type is water-based emulsified fluid are used to reduce the surface roughness of raceway of heat-resistant steel bearing by increasing the linear velocity of grinding wheel,reducing the workpiece speed and the grinding depth per feed and increase the number of grinding.By reducing the linear velocity of grinding wheel and the rotational speed of workpiece and reducing the grinding depth.Reducing the grinding depth of grinding wheel is beneficial to the generation of surface residual compressive stress in tri-lobe raceway.Through the research in this paper,the best grinding process parameters and tool selection for cylindrical roller bearings with Cr4Mo4V tri-lobe raceway are obtained,and the key factors and laws affecting the shape and surface quality of the tri-lobe raceway of cylindrical roller bearings were summarized.Provides theoretical support for the processing of non-round raceways in cylindrical roller bearings... |
PDF Full Text Request