Improvement Of NC Lathe Suitable For Bearing Ring Machining

Bearing is one of the most important parts in today's mechanical equipment,but for most domestic bearing manufacturing enterprises,the main production equipment is still based on traditional hydraulic lathe or general CNC lathe at present.There is no special CNC lathe equipment which is suitable for bearing ring processing in the market.It is of great significance to design a professional CNC lathe according to the processing requirements,which is with higher accuracy,higher efficiency,suitable for the bearing industry,and can solve the processing pain points of the industry,it is quite important for the transformation and upgrading of the whole bearing industry to upmarket manufacturing.Therefore,this paper focuses on the research and improvement of the existing universal full-function CNC lathe i5T3.3(3628s)of SMTCL,and improvement of spindle rigidity and cooling chip removal system,so that it can be transformed from the traditional general-purpose equipment to the special equipment which can meet the industry's exclusive needs,in order to develop the bearing industry market and enhance the market share of product subdivision.By collecting the statistical data of the failure of i5T3.3 NC lathe in recent years,it is found that the failure rate of equipment in bearing enterprises is higher than the average level in three aspects:processing accuracy,surface quality and chip removal machine.Then according to the causes of the failure,it is concluded that the equipment needs to be improved in three aspects:equipment rigidity,chip breaking and long chip discharge.In this paper,the processing specificity of bearing hard turning is analyzed.The finite element static analysis and modal analysis of the whole machine of i5T3.3 NC lathe are carried out by ANSYS WORKBENCH 16.0 software under the condition of hard turning load.It is found that the main deformation position of the machine tool in the process of processing is the spindle part.Then the static analysis of the spindle box is carried out,the result shows that the most influential factors on the deformation is the spindle unit.Finally,through theoretical calculation,a feasible scheme is provided to upgrade the structure of the spindle unit,that is,replacing an angular contact ball bearing at the front end of the spindle unit with a double row cylindrical roller bearing,which increases the rigidity of the spindle unit by 2.2 times under the hard turning parameters.In addition,the cooling system and chip removal system are improved and upgraded to solve the problems of difficult chip breaking and long scrap removal in bearing steel processing.The cutting experiments of bearing steel were carried out under different cooling pressures.The results show that the cutting chip breakage of bearing steel has been significantly improved and the service life of the blade has been significantly improved under the high-pressure cooling condition of 7MPa.According to the discharging principle of chain-plate scrap removal machine with long rolled iron scraps,the structure,lifting angle,form of chip removal port and operation control of the scrap removal machine are improved to meet the processing requirements of bearing steel materials.In this paper,finite element static analysis and modal analysis are used for the i5T3.3 NC lathe,which provides a theoretical basis for the further improvement of spindle rigidity.According to the problems encountered in the processing of bearing industry,the improvement of cooling system and chip removal system can effectively enhance the competitiveness of SMTCL in the market.This analysis provides a reference for the improvement direction of other products of SMTCL.