Design And Characteristic Analysis Of Hydro-Mechanical Continuous Variable Transmission

Gearbox is the core part of vehicle system having big artistic influence on the operation quality of vehicle.Carry out the research of the gearbox which is adapting to agricultural machinery operation features in the Xinjiang having became the issue that needed to be addressed as a matter of urgency.The Hydro-mechanical Continuously Variable Transmission(HMCVT)not only have excellent characteristics of continuously adjustable transmission ratio?super power transmission?high efficiency,but also have excellent maneuverability and great fuel economy.There were still few researches on HMCVT used on agricultural vehicles in China.Carrying out the research which is adapting to agricultural machinery operation features in the Xinjiang not only can provide new trains of thought for agricultural machinery,but also can provide basis for the further research of CVT technology of agricultural machinery.This research is mainly focused on the objective that design a new HMCVT in the Xinjiang,the specific contents are follows:(1)The research analyzed forms and features of the power distribution and power converge characteristics of the fixed axis gear and the planetary gear institutions;established arithmetic transmission,geometric transmission,continuous transmission theoretical model of HMCVT;designed a arithmetic geometric torque distribution speed confluence HMCVT transmission scheme which combines variable displacement pump-fixed displacement motor with double planetary row.(2)The research designed transmission structure scheme and realized control logic of HMCVT by using the combination of clutch and brake.The mechanical power flow and hydraulic power flow dynamic route of HMCVT has been analyzed.The research established each section output speed theoretical model of HMCVT and finished work parameter calculation and type selection design of the hydraulic system components which meeting the requirements of general drive-ratio,geometric transmission,continuous transmission theoretical model of HMCVT.Thus,character of speed and displacement ratio,characteristic curve of cotton picker speed variation with the engine speed,the torque characteristics,and the power split ratio of HMCVT has been analyzed.(3)The research completed the structural design of HMCVT and two double planetary row design schemes have been put forward,then,determines the final scheme which is fast to install by comparing the two renovation methods for the two double planetary row design schemes.Two support mechanism used of pairs of planetary gear row have been designed in this study to improve the stability of pairs of planetary gear row,then the shaft,enclosure and the whole machine structure also have been designed.Finally,the research completed product drawings and process the prototype of HMCVT.(4)The research put forward the design requirements of HMCVT test platform and the architectural placement has been designed.The mechanics part,diagram clutch part and variable pump connect with quantitative motor part of HMCVT test platform not only have been designed in this research,but also the measurement and control systemhave been designed.Finally,the rudiment of test platform of HMCVT has been built.