Analysis On The Work Characteristic Of Planetary Transmission Of Loader

Compared with other gear transmission, planetary-gear transmission has its advantages:small volume, light weight, compact structure, high efficiency etc. and currently has been more and more applied in the engineering machinery. In the process of the design planetary transmission, some problems must be taken into consideration seriously, for example:each component rotational speed, torque variation characteristics, transmission efficiency, Power flow and whether there is circulating power etc. In addition, some problem should also pay much attention, for example:gear contact force change characteristics, the stress distribution and dynamic analysis of gear teeth key nodes stress.The planetary transmission research of this paper was subsidized by the national natural science foundation "Study on the Key Technologies of Powertrain Load Spectrum of Wheeled Vehicle"(No:50805065).the paper takes a planetary transmission of loader for reaserch. Firstly, rotational speed, torque and transmission efficiency are analyzed in theory; Secondly, Powertrain mathematical model and the corresponding simulation model are built; Thirdly, Based on ADAMS and Simulink software, the paper establishes a combined simulation model and then analysis gearbox working characteristics. Finally, Based on Hypermesh and RecurDyn software, the paper establishes the rigid-flex multi system model by flexibling key gears.and then analysis gear contact force change characteristics, the stress distribution and dynamic analysis of gear teeth key nodes stress.Thesis mainly work and content as follows:(1) Chapter 1 presents the background and significance of the research; After consulting numerous date home and aboard. the paper summarizes the domestic and foreign research profile of planetary gearbox. And then some problems existing in the process are proposed, finally The methods used in the thesis and main works are introduced.(2) The paper takes a planetary transmission of loader for reaserch. rotational speed, torque and transmission efficiency are analyzed in theory;(3) In order to analysis gearbox working characteristics. The paper does the following jobs. Firstly, Engine, Hydraulic torque converter mathematical model and the corresponding simulation model are built; Secondly, planetary transmission Virtual prototyping model are built; Thirdly, drive axle, Vehicle mathematical model and the corresponding simulation modle are built; Finally, Based on ADAMS and Simulink software, the paper establishes a combined simulation model.(4) The paper reaserch Planetary Transmission Work Characteristics nder the ten kinds of working conditions. Content as follows:Analysis on rotational speed, torque and transmission efficiency under the same working condition;Under the different working conditions, analysis on rotational speed, torque transmission efficiency, clutch and brake torque variation characteristics. It turnes out that under the same working condition,the lowest transmission efficiency is planet row Five and others are higher than 97percent. It's worth noting that transmission efficiency in forward gear is higher than reverse gear in the same working condition.;Under the different working conditions, the highest transmission efficiency is forward second gear, Comparatively spesking, the lowest is forward first and fourth gear;(5) Based on Hypermesh and RecurDyn software, the paper establishes the rigid-flex multi system model by flexibling key gears.and then analysis gear contact force change characteristics, the stress distribution and dynamic analysis of gear teeth key nodes stress. It turnes out that compared with pitch circle,root part, gear teeth tip key nodes is greater, and sides stress is greater than middle.