Stiffness calculation method of spur gear pair with tooth length modification and misalignment
In order to study the stiffness excitation of spur gear pairs with tooth length modification and misalignment,a general analytical method of time varying meshing stiffness for spur gear pairs with tooth length modification and misalignment was proposed.Firstly,the models of tooth length modification and misalignment were established,and the formula for calculating the total error of spur gear tooth surface was derived.Then,based on the theory of elasticity,tooth contact analysis(TCA),and loaded tooth contact analysis(LTCA),the meshing characteristics such as contact point,instantaneous contact line and contact trace of spur gear pair with tooth length modification and misalignment under loading were calculated.Based on the potential energy method and slice theory,the geometric stiffness,coupling stiffness,Hertzian contact stiffness,and gear foundation stiffness models were constructed,and then the improved analytical formula of time varying meshing stiffness of spur gear pair with tooth length modification and misalignment was derived.Finally,the proposed analytical model was verified by comparing with the results of finite element method.The stiffness excitation of spur gear pair with tooth length modification and misalignment and the influences of different tooth length modification and misalignment on stiffness excitation of spur gear pair were analyzed.The results show that the calculation error of the proposed method of time varying meshing stiffness for spur gear pairs with tooth length modification and misalignment is 3%,which can accurately and effectively analyze the meshing stiffness of spur gear pair with tooth length modification and misalignment,and provides a theoretical basis for the modification design of gear transmission system.