Research On Strength And Dynamic Characteristics Of Orthogonal Face Gear Drives

An investigation on meshing characteristics, strength and dynamic characteristics of theorthogonal face gear(FG) drives is made in this paper. Among them, the meshing characteristicsinclude the equations of FG tooth, tooth width design, contact path and the calculation of contactratio. The tooth contact stress, the bending stress and the scuffing of FG drives are included in theanalysis of the strength characteristics, and the linear and nonlinear dynamic responses are studied inthe investigation of dynamic characteristics of FG drives.In the research on the meshing characteristics of FG drives, the equations of FG tooth, thelimiting equations of undercutting and pointing of FG are derived, and correspondingly the minimuminner radius and maximum outer radius coefficient is proposed. Visualizing contact path, and theeffect of transmission parameters and misalignment errors on the location of contact path is studied.The method to achieve high contact ratio of FG drives is analyzed, and parameter range is obtainedwith the contact ratio beyond two.The principle curvatures of tooth surfaces and principle relative curvatures of FG drives in pointcontact are analyzed, and the distribution of these curvatures on tooth surface and their variation withtransmission parameters are obtained. Based on the Hertz theory, the formulae for calculating thetooth contact stress of FG drives is established，and the influences of transmission parameters andmisalignment errors for tooth contact stress is investigated, which includes shaft angle error, shaftcrossing error and axial shift error.According to the meshing characteristics of FG drives, the tooth width of the three-teethgeometric model of FG is developed for calculating the bending stress. Using orthogonal experimentmethod, the design parameters is definited.The distribution of bending stress of FG and spur gear iscalculated by finite element mothod, and a expression of bending stress of FG drives is obtained. Thecorrectness of the expression of spur gear bending stress is testified by the experimentalinvestigations.The tooth surface relative speed, tooth surface sliding speed and the friction coefficient arepresented, and their variation with transmission parameters is obtained in this paper. Based on the H.Blok’s theory, the formulae for calculating the transient contact temperature of a FG drive is presented.The influence of parameters on the transient contact temperature of a FG drive, including transmissionparameters, the shaft angle error, shaft crossing error and axial shift error, is analyed.Based on the theory of the concentrated parameter, a three-dimensional dynamic model with multiple degrees of freedom for the FG transmission system is developed. Using the Runge-Kuttanumerical integral method, the linear and nonlinear dynamic responses of the FG transmission systemis obtained, and the dynamic behavior of FG transmission system including kinetic load modulus,frequency response characteristics and dynamical bifurcation, is analyzed with main parameters.