Analysis of geometric difference of opposite tooth flanks for traction helical gear pairs in railway transit train
GOU Xiangfeng
LI Huijie
Abstract：[Objective]The influence of the geometric difference of opposite tooth flanks on the contact line length and meshing performance of traction helical gear pairs for rail transit trains was analyzed to reveal the formation mechanism of the transmission performance difference of traction gearboxes during the train's upward and downward travel,and make up for the deficiency that the geometric difference of opposite tooth flanks of helical gears is not considered in existing studies.[Methods]Firstly,the geometric difference angle of opposite tooth flanks was defined,and its calculation formula was derived to provide a parameter basis for the quantitative analysis of the tooth back contact line length.Secondly,combined with the characteristics of the tooth back contact surface and the geometric difference of opposite tooth flanks,a calculation formula for the tooth back contact line length was established to explore the coupling influence law of the geometric difference of opposite tooth flanks and backlash on it.Then,a multi-state meshing dynamic model of helical gear pairs considering the geometric difference of opposite tooth flanks was constructed,and the dimensionless normalization of the model was completed.Finally,the dynamic characteristic analysis of the system was carried out through numerical calculation to clarify the system motion characteristics under different meshing frequencies.[Results]The results show that the geometric difference of opposite tooth flanks leads to an obvious phase difference between the contact line lengths of the tooth flank and the tooth back,and the influence of backlash on the tooth back contact line length increases with the increase of the backlash value;when the dimensionless meshing frequency ω<0.33,the system maintains a stable single-period motion without tooth disengagement;when 0.33≤ω≤0.37,the system presents a short-term tooth back contact phenomenon;with the increase of meshing frequency,the tooth back contact phenomenon disappears completely,and the system presents tooth surface collision and tooth disengagement.The geometric difference of opposite tooth flanks has a significant influence on the dynamic characteristics of helical gear pairs with frequent reversing,and the relevant analysis results can provide a reference for the design and optimization of traction helical gear pairs for rail transit trains.
Keywords：Helical gear pairGeometric difference of opposite tooth flanksTooth back contact lineBacklashMulti-state mesh
Publication Date：2026-05-31
Online Publishing Date：2026-09-12(First online date of this platform, not the publication date of the document)
Pages：9( 33-41 )