Sliding friction effect on dynamics of crossed beveloid gears with small shaft angle

We propose a new method of incorporating the gear sliding friction model and loaded mesh model into an analytical nonlinear crossed beveloid geared vibration model to evaluate the mesh and dynamic characteristics. A 3-dimensional quasi-static loaded tooth contact analysis is employed and the derivation of distributed sliding friction forces and synthesis of frictions to the effective form is applied in the nonlinear dynamic analysis. Using the proposed method, the excitation effects of frictions on tooth mesh and dynamic responses at different load levels are found and investigated. The analysis results show that the existence of sliding frictions between the engaged teeth indeed tends to affect the contact pattern, normal load distribution and maximum contact pressure, but it is unsubstantial. The torque load effect of friction is found with greater degressive influence on mesh stiffness and transmission error at heavier load case. The magnitude and directionality of sliding friction on effective total engaged teeth exhibit less obvious variations than on each tooth due to the contributions from multiple teeth effect. Also, friction excitations tend to decrease the dynamic mesh force slightly for both light and heavy load cases.