Effects of tooth-crack-induced mesh stiffness on fault signals of a planetary gear train

Dynamic features of planetary gear train with tooth errors

Proceedings of the Institution of Mechanical Engineers Part C Journal of Mechanical Engineering Science ◽

10.1177/0954406214549503 ◽

2014 ◽

Vol 229 (10) ◽

pp. 1769-1781 ◽

Cited By ~ 6

Author(s):

Zaigang Chen ◽

Yimin Shao

Keyword(s):

Gear Tooth ◽

Planetary Gear ◽

Transmission Error ◽

Geometric Error ◽

Gear Train ◽

Dynamic Features ◽

Mesh Stiffness ◽

Planetary Gear Train ◽

Proposed Model ◽

Dynamic Excitations

As one of the inherited displacement excitation sources which are related to the gear vibration and noise problems, gear transmission error always consists of two parts: gear tooth geometric error and tooth elastic deformation under transmitted load. The gear tooth geometric errors were directly employed as the displacement excitations in previous papers, which are not accurate. In this paper, a new method is developed to transform the gear tooth errors (TEs) to be the appropriate dynamic excitations through the mesh stiffness and the unloaded static transmission error (USTE), where the obtained displacement excitation curves, namely the USTE curves, are very different from the TE curves. Incorporation of the proposed model into the dynamic model of a planetary gear train enables the investigation of the TE effect on the dynamic excitations and vibrations. Two groups of TEs with different amplitudes are employed in the case studies. The results verify that the micro-scale TEs influence not only the dynamic displacement excitation, but also the total mesh stiffness and the planetary gear vibrations greatly.

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Nonlinear Dynamics of a Power-Split Transmission Unit with a Planetary Gear Train and Selectable One-Way Clutches

Complexity ◽

10.1155/2020/8729365 ◽

2020 ◽

Vol 2020 ◽

pp. 1-16

Author(s):

Zhizhou Jia ◽

Pingkang Li

Keyword(s):

Comprehensive Evaluation ◽

Damping Ratio ◽

Planetary Gear ◽

Transmission Error ◽

Gear Train ◽

Mesh Stiffness ◽

Parallel Transmission ◽

Planetary Gear Train ◽

Power Split ◽

In Series

A Planetary Gear Train (PGT) can be used in series-parallel transmission to redistribute powers. Selectable one-way clutches (SOWCs), compared with traditional friction clutches, can simplify controls and diversify patterns especially for hybrid transmissions. In this paper, a nonlinear torsional model of a power-split PGT coupled with three SOWCs is proposed. Piecewise nonlinearities of SOWCs as well as clearance, time-varying mesh stiffness, and synthetic transmission error of the PGT are considered. With a specified group of comprehensive evaluation indices, influences of piecewise nonlinearities of SOWCs are explored. Simulation results show that the piecewise nonlinearities of SOWCs can diminish collision range and reduce resonances of the PGT. Further research studies on parameter configurations of each SOWC reveal that of the three SOWCs, stiffness and radius of the SOWC connected to the sun gear of the PGT are dominant factors. Large stiffness and effective radius of the SOWC render the PGT fall into chaos on lower meshing frequencies; however, enormous impact vibrations occur to the SOWC if it gets too soft. Additionally, the increase of the damping ratio of the SOWC connected to sun gear can distinctly reduce the vibration and maximum dynamic load of the system on the entire working range.

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Optimization of Compound Planetary Gear Train by Improved Mesh Stiffness Approach

Volume 4A: Dynamics, Vibration, and Control ◽

10.1115/imece2017-70403 ◽

2017 ◽

Cited By ~ 1

Author(s):

Jianwu Zhang ◽

Han Guo ◽

Liang Zou ◽

Haisheng Yu

Keyword(s):

Planetary Gear ◽

Coupling Model ◽

Gear Train ◽

Time Varying ◽

Mesh Stiffness ◽

Planetary Gear Train ◽

Planetary Gear Trains ◽

Hybrid Transmission ◽

Gear Trains ◽

Potential Energy Method

An improved mesh stiffness approach is presented for optimization of vibration and noise performance of the planetary gear trains in a full power split hybrid transmission, in which mesh stiffness time-variability and biaxial gear stiffness couplings in gear pairs are taken into account. For improving accuracy of the mesh stiffness in double teeth-meshing region for spur gear pairs, a simplified solution to the loading gear deformations counting for time-varying mesh stiffness of the helical gear pairs is proposed, based on the integral potential energy method and FEM simulation. By the new biaxial coupling model, effects of gear body and tooth coupled stiffnesses on gear pair vibro-acoustic responses are also investigated and approved to be considerable. Numerical examples with optimal analyses of the specified planetary gear trains for the full hybrid transmission are provided. Numerical solutions of eigen frequencies and vibration modes for the gear pairs with a variety of time-varying mesh stiffnesses are constructed by the biaxial coupling model and Fourier Series. The dynamic parameters optimization of the compound planetary gear train is then conducted. The optimized planetary gear system is applied in the full hybrid transmission and bench tests for its vibro-acoustic performance are also undertaken. Computational predictions and experimental results are shown to be in fairly good agreement.

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Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2015-48022 ◽

2015 ◽

Cited By ~ 1

Author(s):

Fengxia Lu ◽

Rupeng Zhu ◽

Haofei Wang ◽

Heyun Bao ◽

Miaomiao Li

Keyword(s):

Degrees Of Freedom ◽

Sliding Friction ◽

Planetary Gear ◽

Gear Train ◽

Variable Step Size ◽

Step Size ◽

Planetary Gear Train ◽

Gear Mesh ◽

Meshing Stiffness ◽

Nonlinear Dynamics Model

A new nonlinear dynamics model of the double helical planetary gear train with 44 degrees of freedom is developed, and the coupling effects of the sliding friction, time-varying meshing stiffness, gear backlashes, axial stagger as well as gear mesh errors, are taken into consideration. The solution of the differential governing equation of motion is solved by variable step-size Runge-Kutta numerical integration method. The influence of tooth friction on the periodic vibration and nonlinear vibration are investigated. The results show that tooth friction makes the system motion become stable by the effects of the periodic attractor under the specific meshing frequency and leads to the frequency delay for the bifurcation behavior and jump phenomenon in the system.

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