Analysis of the influence of continuous variable characteristic parameters on the quality of HMCVT transition

YANG Zhaohu; DU Youhong; TAN Yunying; LI Qingtao; CHEN Xinghai

doi:10.16578/j.issn.1004.2539.2025.10.016

Abstract：[Objective]To analyze the stage changing quality of small and medium-sized tractors equipped with hydro-mechanical continuously variable transmission(HMCVT)in the process of power changing,based on a HMCVT with continuously variable characteristic parameters,the traditional gear planetary transmission structure was changed into the traction planetary transmission structure,and a multi-stage HMCVT system was proposed.[Methods]Considering the influence of changing time and displacement ratio of the hydraulic system on the stage changing quality,AMESim modeling and simulation analysis of the multi-stage HMCVT system was carried out by adding a variable concerning which the characteristic parameters of the traction planetary array were continuously changing.When the change period t0=0.8 s was set in the simulation,multi-parameter adjustment analysis was carried out on the three evaluation indexes of the change period quality,such as velocity drop,impact degree and sliding power,in the characteristic parameter k 1.5-2.[Results]The design of the three-stage HMCVT system can reduce the maximum sliding power by 25.6%or the maximum impact degree by 20.84%by changing the value of the characteristic parameter k in the L and H stages.By changing the value of the characteristic parameter k in the S and L sections,the sliding work can be reduced by 6.68%,but the impact of changing the characteristic parameter k on the impact degree changes within 1%.The overall velocity drop will increase with the increase of the characteristic parameter k.The research results can provide reference for further improving the stage changing quality.