Analysis of Dynamic Characteristics of the Multistage Planetary Gear Transmission System with Friction Force

Abstract

Multistage planetary gear transmission system has been widely utilized in engineering practice due to the salient characteristics, such as high bearing load and large speed ratio. This paper addresses a two-stage planetary gearbox and establishes a system coupling torsional dynamical model which considers the time-varying mesh stiffness, friction forces, and interstage coupling factors. Meanwhile, the friction and lubrication states are classified to comprehensively analyze the calculation of friction coefficients under different conditions. Considering the time-varying influence of friction on the tooth surface under the condition of fluid lubrication, the vibration response under parametric excitation is solved by a numerical method. A multistage planetary transmission test bench is built in the back-to-back form so as to test the vibration of the two-stage planetary gearbox. It shows that the simulation results of the dynamical model are consistent with the test data. Consideration of the calculation of friction on the tooth surface and the friction coefficients is helpful for the establishment of the more accurate dynamical model and lays the foundation for the structural design, fault diagnosis, and dynamic optimization of the multistage planetary gear transmission system.

Dynamic characteristics of helical gear with root crack and friction

“…In the equation ( 2), I x is the moment of inertia at the base circle x, A x is the cross-sectional area, and h is the meshing point to the horizontal midline the distance, x is the length from the base circle, E is the Young's modulus, G is the elastic modulus, Figure 2 plots some specific data about involute gear tooth profile and force analysis. M is the bending moment; F a is the component force of the meshing force along the horizontal direction; F b is the component force of the meshing force along the vertical direction; d is the length from the meshing position to the base circle; x is the length from the base circle; A x is the cross-sectional area, I x is the cross-sectional moment of inertia at the distance x from the tooth root, and the calculation is shown in equation (3).…”

“…Due to its very complex system structure and harsh working environment, the gears in the system are often damaged, leading to failures, resulting in immeasurable losses, and even life-threatening in severe cases. 3 Root cracks are a common failure. Cracks are caused by frequent impact.…”

Optimization of planetary gearbox using nature inspired meta-heuristic optimizers

“…1 Multistage planetary gear systems are used in high torque transmission systems of wind turbines, automobiles, ships, helicopters, spacecrafts and tanks due to their compact structure, lightweight, high transmission ratio and weight carrying capacity. [2][3][4][5][6] The planetary gear mechanism consists of the carrier, the planetary gears mounted on the carrier, the sun gear that the planetary gears contact, and the ring gear (Figure 1). When the sun gear is used as a drive gear, the planet gears engage the sun gear and rotate in the opposite direction.…”

“…8,13 Besides, it is difficult to determine the accuracy of the kinetic model due to nonlinear factors and the complex dynamic coupling of multistage planetary gear mechanisms. 6 Thus, these difficulties have driven the use of meta-heuristic optimizers for design optimization of planetary gears. [6][7][8]10,11,[13][14][15][16][17][18][19] Most of the studies in the literature are related to single-stage planetary gear sets and therefore there is a 1 literature gap for the volume minimization of multistage planetary gears.…”

“…6 Thus, these difficulties have driven the use of meta-heuristic optimizers for design optimization of planetary gears. [6][7][8]10,11,[13][14][15][16][17][18][19] Most of the studies in the literature are related to single-stage planetary gear sets and therefore there is a 1 literature gap for the volume minimization of multistage planetary gears. This study is conducted to measure the performance of recent nature-inspired methods in the design optimization of multistage planetary gear mechanisms.…”