| Gear transmission is the most widely used transmission device and the core component of many mechanical and electrical products. As the development of industrial technology, the gear transmission is more and more used under the high-speed and heavy load conditions. Under these conditions, the deformation of gear caused by uneven temperature distribution and the meshing impact generated by manufacture and installation of errors will have a certain degree of damage of gear. At the same time, the fatigue characteristics of gear will become more obvious under the variable load. Therefore, gear profile modification is necessary, because gear tooth modification can make sure the gear meshing transmission has better performance under high speed condition as well as reduce the vibration and noise of gear transmission and also can make the tooth surface load distribution is more uniform must carry on the gear tooth correction. Finally lead to high efficiency of the gear transmission.Research on the gear tooth modification guarantee the accuracy of the gear model which imprecise gear model will partly influence the dynamic contact stress analysis results, therefore, using UGNX created involute tooth geometric equation and the gear root transition curve and parameter function to. create gear models. Under the boundary conditions and constraints loads, the involute gear model was imported into ANSYS/LS-DYNA numerical simulation and it has a nonlinear dynamic analysis when it under the high speed condition in order to obtain gear tooth surface contact stress, strain and acceleration time history curve during high-speed transmission. By comparing the Hertz formula of the maximum contact stress of tooth surface, the rationality of the finite element calculation results can be determined.Using the above mentioned dynamic analysis of the gear at high speed and evolution equations of profile modification can obtain a series of parameters which required for the tooth profile modification and then get the model of gear with different modification curves, then carry on the dynamic calculation of the gear model to set the boundary conditions required for high speed operation. After that, circular curve has a better modification performance comparing the analysis results with curve-linear curve, walker curve and circular curve. The analysis also be operated under the different condition of high speed and it shows that when the circular curve gear profile modification under the condition which the velocity is less than 340rad/s, the gear meshing impact, vibration and noise is small.Similarly, repair gear model for nonlinear dynamic analysis under high speed can be created by combined the nonlinear dynamic analysis results and tooth modification theory. When the gear model is under 300rad/s condition, circumferential displacement can be got by observation, tooth-shaped ends of the arc and drum modification can reduce gear appropriate shock. The maximum contact stress in the direction of the teeth can be extracted, contact stress curve also can be generated, comparing the involute spur gear, gear tooth circular-arc gear and drum gear curve of contact stress can know that drum modification effect is more prominent, the drum corrected gear analysis in different speed range and get the speed is less than 320rad/s, the gear transmission stability.This paper is mainly talk about using the finite element software to make the dynamic analysis the gear model under high speed condition, according to the results of dynamic analysis combined with gear modification theory, resulting in the design of its tooth profile modification and repair tooth-shaped design, modification gears are setting under 300rad/s of the boundary conditions, nonlinear dynamic analysis and to determine the gear modification method and modification parameters for the high speed condition. Through the study of this paper to provide reference data for gear design and better able to meet the engineering application. |
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