Research On The Hydro-Mechanical Continuously Variable Transmission Used In Maize Combine Harvester

Now, the automation level of maize combine harvester in China is low and thereliability under bad environment is poor and the slower travel speed increases thetransportation cost. Hydro-mechanical continuously variable transmission can reducethe impact and improve the economy, easy to automate, so it has been widely used inmilitary machinery, construction machinery, and rarely used in agricultural machinery.Therefore，in-depth understanding of the hydro-mechanical continuously variabletransmission characteristic and researching on its application in maize combineharvester have the important practical significance.This paper has designed the mechanical structure and control method ofhydro-mechanical continuously variable transmission for4YZ-3type maize combineharvester and done the simulation analysis.According to the technical requirements of4YZ-3maize combine harvester, ithas created the three-dimensional CATIA model of mechanical and done detailedanalysis of the ratio characteristic, torque characteristic and efficiency characteristics.Use the bond graph theory to establish the F4segment simulation model oftransmission, and do the efficiency simulation. Select the engine for4YZ-3cornharvester and establishment of a mathematical model to get the best economic curve.Do the best economical match based on the engine and the transmission’s operatingconditions. Propose walking and operation control method according to the differentrequirements of the transmission. Create a Simulink simulation model of the vehicle.Simulations validate that, the control method can make the engine work near theeconomy curve; Transmission can meet the different requirements of the two modes;Mutation load of operation mode, the control method can change the engine power toensure the quality of operations.The results of this study have some theoretical and practical significance inhydro-mechanical continuously variable transmission used in maize combineharvester.