Research On Design And Load Sharing Characteristic Of Encased Differential Gear Train With Parallel Double Row Planets

The encased differential planetary gear transmission system is mainly used in the main reducer of heavy equipment such as engineering machinery,crane and ship power transmission system,There are some problems such as large vibration and impact,uneven distribution of planetary wheel load,which restricts the excellent characteristics and service life of the transmission system.In view of this,an encased differential gear train with parallel double row planets is proposed in this paper.The planetary gears of the differential train and star gears of the encased train are changed from the traditional single row uniform structure to the double row parallel space uniform structure.so that double planetary gears and star gears can participate in the power distribution,reduce the impact and vibration,make the load distribution more uniform,improve the load sharing performance and improve the service life of transmission system.The transmission principle of encased differential gear train with parallel double row planets is analyzed.According to the transmission ratio condition,adjacent condition,concentric condition and assembly condition of the transmission system,the basic parameters of the gears of the encased differential gear train with parallel double row planets are determined,and the encased differential gear train with parallel double row planets is designed.The tooth contact strength 、root bending strength and tooth surface bonding strength of each gear in the transmission system are checked and calculated,and the transmission efficiency of the transmission system is calculated.The finite element simulation analysis of t encased differential gear train with parallel double row planets is carried out to verify that the gears of the transmission system meet the requirements of gear strength;the finite element modal analysis of t encased differential gear train with parallel double row planets is carried out to verify that the transmission system will not produce resonance phenomenon in normal operation.Equivalent elastic displacement formulas for calculating eccentricity errors and installation errors of components of transmission system are deduced,and load distribution coefficient formulas of transmission system are deduced based on elastic mechanics analysis method.The effects of eccentricity errors and installation errors on load distribution of transmission system are analyzed,and the effects law of eccentricity errors and installation errors on load sharing characteristics of transmission system are obtained.The virtual prototype model of the planetary gear double row parallel encased differential gear transmission system and traditional single row encased differential planetary gear transmission system is established.The dynamic simulation of the virtual prototype model are carried out by means of ADAMS software.The contace force changing situation in meshing transmission process is analyzed,and the simulation results of the two systems are compared and analyzed.