| Practice has proved that only by improving the gear manufacture precision and installation accuracy to meet the increasing demands for high performance of gear is not enough, and it will also greatly increase the manufacture cost of gear transmission. Numerous studies have proved that the appropriate gear modification can compensate for the error caused by tooth load, reduce the gear meshing impact, reduce the vibration and noise, improve the load distribution of gear tooth and gear bearing capacity, improve the stability and reliability of the gear transmission to a certain extent. Therefore, the appropriate modification of helical gear is an effective method to reduce the impact, vibration and noise, improve the performance of gear transmission under the condition of not changing basic parameters of gear. However, when the selection of gear modification methods and parameters is unreasonable, gear transmission performance will be deteriorated. The article studied the modification of a helical gear pair of a certain type of coal transport machine reducer through using the finite method which combined contact finite element analysis with dynamic simulation. The research of the article completed the determination of gear modification scheme and experimental verification more intuitively and accurately. The main tasks which have been done are as follows:1 According to the geometric size calculation formulas of helical gear, the involute equation, helix equation were deduced, and more precise helical gear parametric 3D model was established through the use of more precise modeling method of gear tooth- mixed scanning method in the 3D drawing software Pro/E. And then finished the virtual assembly of helical gear pair without interference.2 Gear contact was analyzed into the finite element software ANSYS Workbench. According to the meshing properties of gear transmission and the tooth profile modification principle, the elastic deformation of gear tooth was obtained by combining with the finite element contact analysis results to determine the appropriate modification amount, then the modification curve and length were determined. Studied the tooth axial modification method, from the comprehensive consideration such as processing cost and effect, applied drum modification whose processing method is simple and modification effect is better on the small helical gear studied in the article.3 Dynamic meshing simulation of helical gear pairs before and after the modification was carried out in the dynamic simulation software ADAMS. The results verified that the modification scheme in the paper can effectively reduce the maximum mesh stress during the process of gear engagement, reduce the meshing impact, so as to improve the stability and reliability of helical gear transmission.4 Analyzed the modification processing method of the helical gear pair and deduced the relation between corresponding processing parameters.Then processed the helical gears.5 Built the vibration and noise test platform on which the vibration and noise test of the before and after modification helical gear pairs was carried out.In this paper, the results of the vibration and noise test verified verified the gear modification scheme determined by the finite element method can effectively reduce the vibration and noise combining the actual working condition of gear, so as to improve the comprehensive performance of the gear. |
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