Study On Effect Of Displacement Coefficient On The Transmission Quality Of High Speed Gear

Gear transmission is widely used in various mechanical transmission equipment,because of it?s high efficiency,compact structure,reliable operation and long service life.Gear pair can adapt to various operating conditions and can maintain good transmission quality by selected one appropriate displacement coefficient.The study mainly solves the problems of high noise and high temperature during operation of the high-speed gear pair of the electric hedge trimmer.At present,there are few researches on such new electric equipment transmission gears at home and abroad,so there is no corresponding.The study is based on the working conditions of this gearbox,to analyze the influence of the displacement coefficient on the transmission quality of the gear transmission system under ultra-high speed and impact load.Finally,it is hoped that the corresponding research results and methods can be used to guide the gear pair design of subsequent similar equipment.In this paper,there has modeled the high-speed shaft gear pair of the existing hedge trimmer by the 3D modeling software NX10.0,and then analyzed the thermal stress,maximum deformation and maximum principal stress by the finite element analysis software ANSYS,and finally completed the calculation of the fatigue life of the gear pair.It is concluded that the existing main and driven gears and the corresponding gearbox have unreasonable dimensional tolerance design,comparing the total deformation with the design tolerances of the production drawings.Through the calculation of the fatigue life of the main and driven gears,it is concluded that the fatigue life of the main and driven gears is very different.According to the wooden barrel principle,the existing displacement coefficient selection is unreasonable.Under the premise of not changing the existing gear transmission parameters,there has analyzed the main and driven gears in groups to optimize the existing gear pair parameters,according to the gear displacement coefficient.In this paper,there determined the total displacement coefficient preferentially,and the range of the main and driven gears' separately.By the orthogonal experiment principle,there completed the models under the different values,and finite element analysis.At last there has drawn through the conclusions as follows.First: For the driving gear in the paper,the increase of the displacement coefficient is beneficial to its resistance to thermal stress.For the driven gear,as the displacement coefficient increases,the deformation of the gear increases first and then decreases under the action of thermal stress.Second: For such small electric equipment,it's should be considered that the influence of gear pair's thermal deformation in the design.In the study,it completed the optimization of the related gears of the hedge trimmer and the corresponding gearbox through the analysis results.Third: Through analysis,it has obtained the influence rule of tooth root fillet and meshing precision on finite element analysis of transmission gear.Forth:By analyzing the main and driven gears with different displacement coefficients,it has obtained the variation rules of the maximum principal stress and maximum deformation with different displacement coefficients.