Calculation Technology Of Bearing Life At Cycloid Of 2K-V Reducer

2K-V type reducer(called Rotary Vector in Japan,referred to as RV reducer)is a planetary transmission mode that combines cycloid pin wheel transmission and involute gear transmission.It has large transmission ratio,compact structure,stable transmission and high transmission accuracy,long service life and other advantages.Therefore,industrial robots use a large number of 2K-V reducers in the joint arm transmission part.At present,the service life of the domestically produced 2K-V reducer is far behind the international advanced level,and a large amount of foreign equipment is still needed in industrial production.A large number of theoretical studies and practical applications show that the life of the 2K-V reducer depends on the life of the bearing between the cycloid wheel and the crankshaft.Based on high-precision size measurement,ADAMS simulation and theoretical calculations,this paper proposes a method for calculating the life of the boom bearing.(1)Under the rated working load,the bearing load of the rotating arm at the cycloid is analyzed and calculated for the 2K-V reducer.First of all,the load of the arm bearing at the cycloid of the 2K-V reducer is calculated by numerical analysis.On this basis,a high-precision image measuring instrument was used to measure the meshing profile point data of a 2K-V reducer part produced by a certain company,and the reducer model was constructed with threedimensional modeling software,and the ADAMS software was imported for dynamic calculation and output the actual force on the bearing at the cycloid wheel of the 2K-V reducer under conditions.(2)According to the dynamic calculation,the maximum load of the rotary arm bearing at the cycloid wheel is obtained,and the maximum contact stress inside the bearing is calculated.The Hertz contact theory and ANSYS software are used to calculate the maximum contact stress inside the roller bearing respectively,which is 1924 MPa and 2023 MPa,which does not exceed the allowable stress requirement(4000MPa).(3)Considering the force of the bearing with the angle of rotation obtained by theoretical and dynamic calculations,and fusing the bearing life calculation theory and the fatigue damage accumulation theory,the life of the rotating arm bearing at the cycloid of the 2K-V reducer is calculated.The influence of some parameters of the 2K-V reducer on the life of the rotary arm bearing at the cycloid is analyzed through theoretical calculations.The results show that the fatigue life of the rotary arm bearing at the cycloid of the 2K-V type reducer is 6767 hours under theoretical use conditions,and its life is 2139 hours calculated according to the dynamic force.The manufacturing accuracy of parts has a great influence on the life of the bearing.Using the comprehensive performance test bench of 2K-V reducer,using accelerated test to simulate the actual fatigue life of the rotating arm bearing is 2600 hours.The calculated results are basically consistent with the experimental results.In summary,this paper uses theoretical analysis and numerical simulation to calculate the bearing load at the cycloid of the 2K-V reducer,and proposes a bearing life calculation method.The research has certain theoretical significance and engineering application value.