The RV Reducer Crankshaft Bearing Grease Elastohydrodynamic Lubrication Analysis

RV reducer is one of the key components of industrial robots,it composed of cycloid wheel drive mechanism and involute cylindrical gear planetary transmission mechanism,it is assembled in the servo motor,play a role in controlling the robot movement.China's industrial robot RV reducer mainly rely on imports,reducer related technology is mainly in the hands of foreign companies,there is few study the relevant technology of the RV reducer also is relatively backward,especially lubrication technology research of the reducer related spare parts.At present,the related parts and components of the RV reducer lubrication technology research is still less,the abnormal crank shaft parts,especially more prone to abnormal crankshaft parts,crankshaft bearing life determines the longevity of the RV reducer,an RV reducer crank shaft bearing lubrication technical research,makes up the blank of the researches in this field in China,to our country the RV reducer with the development of the bearing components has important theoretical significance and practical significance,expand the RV reducer crank shaft bearings Lubrication technology research,to make up for the gaps in the field of research in China,it has important theoretical significance and practical engineering significance for the development of bearing parts of RV reducer.In this paper,the industrial robot RV reducer is studied systematically,applied to the mechanical design,equipment lubrication,tribology,numerical analysis,computer program design and so on.The crankshaft cylindrical roller bearing and tapered roller bearing of the RV reducer is analyzed under the actual working conditions.This paper analyzes the roller bearing load distribution and the motion parameters in the RV reducer actual working condition.Based on the Ostwald model,the crankshaft related bearing line contact grease lubrication isothermal elastohydrodynamic lubrication model was established,using multigrid method to solve for the crank shaft cylindrical roller bearing and tapered roller bearing grease elastohydrodynamic lubrication numerical solution under the actual working condition,obtained the roller and the inner contact lubricant film thickness distribution and the pressure distribution,analyzes the effect of the influence of related parameters,concluded as follow:Under the actual operating conditions of RV reducer at different output speed or the same output speed of different grease rheological index,the solution of the crankshaft cylindrical roller bearings and tapered roller bearings lubrication film thickness distribution and pressure distribution are in line with the typical flow lubrication characteristics,the lubrication film pressure distribution has a clear range of the smallest secondary pressure peak,the lubrication film thickness distribution in the secondary pressure peak has a significant necking;with RV reducer output speed of crank shaft of cylindrical roller bearings and tapered roller bearings,the average film thickness and the minimum film thickness increases,the lubricant film pressure with the improvement of output speed increased;the crank shaft at the cylindrical roller bearings and tapered the largest roller bearing lubricant film pressure,the average film thickness and minimum film thickness increased with the increase of rheological index.Under the same RV reducer output speed conditions,the average thickness and minimum film thickness of the cylindrical roller bearing lubricating film are larger than that of the tapered roller bearing,improve the rheological index of grease has the same result,The analysis shows that:at the same output speed,the crankshaft tapered roller bearing maximum force roller unit length of the load is greater,and the average speed of the roller and the inner ring at the contact surface is small,two factors led to the above results.