scholarly journals Vibration Based Diagnosis for Planetary Gearboxes Using an Analytical Model

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Liu Hong ◽  
Yongzhi Qu ◽  
Yuegang Tan ◽  
Mingyao Liu ◽  
Zude Zhou
Keyword(s):  
Analytical Model ◽  
Planetary Gear ◽  
Diagnostic Techniques ◽  
Dynamic Simulations ◽  
Diagnostic Efficacy ◽  
Planetary Gearbox ◽  
Gear Teeth ◽  
Detection And Identification ◽  
Planetary Gear Sets ◽  
Frequency Components

The application of conventional vibration based diagnostic techniques to planetary gearboxes is a challenge because of the complexity of frequency components in the measured spectrum, which is the result of relative motions between the rotary planets and the fixed accelerometer. In practice, since the fault signatures are usually contaminated by noises and vibrations from other mechanical components of gearboxes, the diagnostic efficacy may further deteriorate. Thus, it is essential to develop a novel vibration based scheme to diagnose gear failures for planetary gearboxes. Following a brief literature review, the paper begins with the introduction of an analytical model of planetary gear-sets developed by the authors in previous works, which can predict the distinct behaviors of fault introduced sidebands. This analytical model is easy to implement because the only prerequisite information is the basic geometry of the planetary gear-set. Afterwards, an automated diagnostic scheme is proposed to cope with the challenges associated with the characteristic configuration of planetary gearboxes. The proposed vibration based scheme integrates the analytical model, a denoising algorithm, and frequency domain indicators into one synergistic system for the detection and identification of damaged gear teeth in planetary gearboxes. Its performance is validated with the dynamic simulations and the experimental data from a planetary gearbox test rig.

scholarly journals Fault Diagnosis for a Multistage Planetary Gear Set Using Model-Based Simulation and Experimental Investigation

2016 ◽  
Vol 2016 ◽  
pp. 1-19 ◽  
Author(s):  
Guoyan Li ◽  
Fangyi Li ◽  
Yifan Wang ◽  
Dehao Dong
Keyword(s):  
Fault Diagnosis ◽  
Spectral Characteristics ◽  
Planetary Gear ◽  
Spectral Structure ◽  
Mesh Stiffness ◽  
Planetary Gearbox ◽  
Frequency Components ◽  
Close Frequency ◽  
Simulated Analysis ◽  
Potential Energy Method

The gear damage will induce modulation effects in vibration signals. A thorough analysis of modulation sidebands spectral structure is necessary for fault diagnosis of planetary gear set. However, the spectral characteristics are complicated in practice, especially for a multistage planetary gear set which contains close frequency components. In this study, a coupled lateral and torsional dynamic model is established to predict the modulation sidebands of a two-stage compound planetary gear set. An improved potential energy method is used to calculate the time-varying mesh stiffness of each gear pair, and the influence of crack propagation on the mesh stiffness is analyzed. The simulated signals of the gear set are obtained by using Runge-Kutta numerical analysis method. Meanwhile, the sidebands characteristics are summarized to exhibit the modulation effects caused by sun gear damage. At the end, the experimental signals collected from an industrial SD16 planetary gearbox are analyzed to verify the theoretical derivations. The results of experiment agree well with the simulated analysis.

scholarly journals PITTING DAMAGE LEVELS ESTIMATION FOR PLANETARY GEAR SETS BASED ON MODEL SIMULATION AND GREY RELATIONAL ANALYSIS

2011 ◽  
Vol 35 (3) ◽  
pp. 403-417 ◽  
Author(s):  
Cheng Zhe ◽  
Hu Niaoqing ◽  
Gu Fengshou ◽  
Qin Guojun
Keyword(s):  
Feature Selection ◽  
Test Data ◽  
Grey Relational Analysis ◽  
Model Simulation ◽  
Planetary Gear ◽  
Damage Level ◽  
Planetary Gearbox ◽  
Relational Analysis ◽  
Planetary Gear Sets ◽  
Grey Relational

The planetary gearbox is a critical mechanism in helicopter transmission systems. Tooth failures in planetary gear sets will cause great risk to helicopter operations. A gear pitting damage level estimation methodology has been devised in this paper by integrating a physical model for simulation signal generation, a three-step statistic algorithm for feature selection and damage level estimation for grey relational analysis. The proposed method was calibrated firstly with fault seeded test data and then validated with the data of other tests from a planetary gear set. The estimation results of test data coincide with the actual test records, showing the effectiveness and accuracy of the method in providing a novel way to model based methods and feature selection and weighting methods for more accurate health monitoring and condition prediction.

Analysis of the Housing Vibration of a Rotorcraft Planetary Gear Using a Finite Element/Contact Mechanics Model

2017 ◽  
Author(s):  
Christopher G. Cooley ◽  
Adrian A. Hood
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Planetary Gear ◽  
Time Instant ◽  
Frequency Content ◽  
Contact Conditions ◽  
Gear Teeth ◽  
Mechanics Model ◽  
Parametric Studies ◽  
Frequency Components

This study investigates the planetary gear housing vibration for rotorcraft systems with equally spaced and diametrically opposed planets using a finite element/contact mechanics model. This approach permits accurate housing deflection calculations at each time instant that result from the changing contact conditions on all gear teeth and elastic deformations of each gear. Planetary gears with diametrically opposed planets have larger amplitude vibrations and more frequency content than those with equally spaced planets. Parametric studies show that although the frequency content does not change with changes in the system’s parameters, the amplitudes of response at these frequencies are meaningfully impacted. The frequency components of the acceleration spectra can have additional content when the planetary gear has manufacturing and assembly errors. Each error case results in different frequency content in the acceleration spectra. Understanding these housing vibrations is beneficial for interpreting measured accelerometer signals to detect and classify damage.

scholarly journals CALCULATION OF FORCES FORCING VIBRATION IN A PLANETARY GEAR

2019 ◽  
Vol 1 (7) ◽  
pp. 98-105
Author(s):  
V. A. Golubkov ◽  
V. F. Shishlakov ◽  
A. G. Fedorenko ◽  
E. Yu. Vataeva
Keyword(s):  
Spectral Composition ◽  
Planetary Gear ◽  
Analytical Description ◽  
Dynamic Loads ◽  
Planetary Gears ◽  
Planetary Gearbox ◽  
Gear Teeth ◽  
Elastic Forces ◽  
Allowable Range ◽  
Profile Errors

Most electromechanical devices contain planetary gears. Vibration is the result of the interaction of the teeth and is largely determined by the accuracy of the manufacture of their profile and the error of the step at the production stage, as well as the defects arising in the course of operation. The main elements influencing the vibration of the gears of the planetary gearbox are the deviation of the tooth profiles from the involute and the error in cutting the gear teeth. To reduce the dynamic loads in the contact areas and improve the reliability of gearing, these errors should be monitored and normalized in the allowable range. Based on the analysis of the elastic forces arising in the contact of the teeth, we obtain expressions for the contact stiffnesses and the forces forcing the vibration of the gears. Elastic forces are determined by identifying the deformations that occur at the contact of the gear and wheel teeth. The article describes an analytical description of the spectral composition of the forces that compel vibration, depending on the profile errors and the pitch of the gears of the planetary gear.

scholarly journals Effect of mesh phasing on the transmission efficiency and dynamic performance of wheel hub planetary gear sets

2017 ◽  
Vol 232 (19) ◽  
pp. 3469-3481 ◽  
Author(s):  
Ehsan Fatourehchi ◽  
Mahdi Mohammadpour ◽  
Paul D King ◽  
Homer Rahnejat ◽  
Gareth Trimmer ◽  
...  
Keyword(s):  
Dynamic Performance ◽  
Planetary Gear ◽  
Transmission Efficiency ◽  
Gear Teeth ◽  
Design Attributes ◽  
Frictional Performance ◽  
Planetary Gear Sets ◽  
Noise Vibration ◽  
New Generation ◽  
Mesh Phasing

Transmission efficiency and refinement of planetary wheel hub gearing system are key design attributes for heavy and off-highway vehicles. Reduction of power loss, directly leading to the development of new generation ECO-axles requires analysis of gear contacting conditions for lubricated conjunctions to determine frictional performance. This is also affected by gear dynamics, which is a prerequisite for assessment of noise, vibration and harshness performance. Therefore, a combined tribo-dynamic analysis is essential. There is a dearth of such holistic analysis, particularly for the case of wheel hub planetary systems. The paper presents such an analysis, which has not hitherto been reported in literature. The inexorable interplay of transmission efficiency and noise, vibration and harshness refinement is demonstrated. The key attributes of noise, vibration and harshness refinement and transmission efficiency can pose contrary requirements and near-optimal conditions can be highlighted by mesh phasing of gearing contacts, thus alleviating the need for more complex gear teeth modifications entailing prohibitive manufacturing costs.

The Research on Natural Characteristic and Eigensensitivity of Ravingneaux Compound Planetary Gear Sets

2013 ◽  
Vol 446-447 ◽  
pp. 590-596
Author(s):  
Bo Qian ◽  
Shi Jing Wu
Keyword(s):  
Natural Frequency ◽  
Planetary Gear ◽  
Torsional Stiffness ◽  
Ring Gear ◽  
Vibration Model ◽  
Planetary Gear Sets ◽  
Planet Gear ◽  
Natural Characteristic ◽  
Gear Ring ◽  
The Moment

The dynamic model of Ravingneaux compound planetary gear sets has been built. Then the Natural frequency and vibration model have been solved in the Ravingneaux compound planetary gear sets. The eigensensitivity to parameters have been researched based on the dynamical model. The varying trend of natural frequency according to the varying of parameters have been researched, which include gear mass (sun gear, ring gear , or planet gear), the moment of inertia of gears, the support stiffness , the torsional stiffness.

An Analytical and Numerical Investigation of Modulation Sidebands of a Planetary Gear Under Fluctuated External Torque

2018 ◽  
Author(s):  
Yunbo Yuan ◽  
Wei Liu ◽  
Yahui Chen ◽  
Donghua Wang
Keyword(s):  
Planetary Gear ◽  
Transmission Error ◽  
Operating Conditions ◽  
Radial Acceleration ◽  
External Torque ◽  
Gear Mesh ◽  
Planetary Gear Sets ◽  
Static Transmission Error ◽  
Frequency Modulations ◽  
Mesh Phasing

Certain operating conditions such as fluctuation of the external torque to planetary gear sets can cause additional sidebands. In this paper, a mathematical model is proposed to investigate the modulation mechanisms due to a fluctuated external torque (FET), and the combined influence of such an external torque and manufacturing errors (ME) on modulation sidebands. Gear mesh interface excitations, namely gear static transmission error excitations and time-varying gear mesh stiffness, are defined in Fourier series forms. Amplitude and frequency modulations are demonstrated separately. The predicted dynamic gear mesh force spectra and radial acceleration spectra at a fixed position on ring gear are both shown to exhibit well-defined modulation sidebands. Comparing with sidebands caused by ME, more complex sidebands appear when taking both FET and ME into account. An obvious intermodulation is found around the fundamental gear mesh frequency between the FET and ME in the form of frequency modulations, however, no intermodulation in the form of amplitude modulations. Additionally, the results indicate that some of the sidebands are cancelled out in radial acceleration spectra mainly due to the effect of planet mesh phasing, especially when only amplitude modulations are present.

scholarly journals The Cluster Computation-Based Hybrid FEM–Analytical Model of Induction Motor for Fault Diagnostics

2020 ◽  
Vol 10 (21) ◽  
pp. 7572 ◽  
Author(s):  
Bilal Asad ◽  
Toomas Vaimann ◽  
Anouar Belahcen ◽  
Ants Kallaste ◽  
Anton Rassõlkin ◽  
...  
Keyword(s):  
Induction Motor ◽  
Analytical Model ◽  
Hybrid Model ◽  
Diagnostic Techniques ◽  
Hybrid Finite Element Method ◽  
Laboratory Setup ◽  
Long Run ◽  
Three Phase ◽  
Cage Induction Motor ◽  
Simulation Time

This paper presents a hybrid finite element method (FEM)–analytical model of a three-phase squirrel cage induction motor solved using parallel processing for reducing the simulation time. The growing development in artificial intelligence (AI) techniques can lead towards more reliable diagnostic algorithms. The biggest challenge for AI techniques is that they need a big amount of data under various conditions to train them. These data are difficult to obtain from the industries because they contain low numbers of possible faulty cases, as well as from laboratories because a limited number of motors can be broken for testing purposes. The only feasible solution is mathematical models, which in the long run can become part of advanced diagnostic techniques. The benefits of analytical and FEM models for their speed and accuracy respectively can be exploited by making a hybrid model. Moreover, the concept of cloud computing can be utilized to reduce the simulation time of the FEM model. In this paper, a hybrid model being solved on multiple processors in a parallel fashion is presented. The results depict that by dividing the rotor steps among several processors working in parallel, the simulation time reduces considerably. The simulation results under healthy and broken rotor bar cases are compared with those taken from a laboratory setup for validation.

A Three-Dimensional Load Sharing Model of Planetary Gear Sets Having Manufacturing Errors

2015 ◽  
Author(s):  
Nicholas D. Leque ◽  
Ahmet Kahraman
Keyword(s):  
Three Dimensional ◽  
Planetary Gear ◽  
Load Sharing ◽  
Distribution Model ◽  
Gear Mesh ◽  
Position Errors ◽  
Proposed Model ◽  
Manufacturing Errors ◽  
Manufacturing Tolerancing ◽  
Planetary Gear Sets

Planet-to-planet load sharing is a major design and manufacturing tolerancing issue in planetary gear sets. Planetary gear sets are advantageous over their countershaft alternatives in many aspects, provided that each planet branch carries a reasonable, preferably equal, share of the torque transmitted. In practice, the load shared among the planets is typically not equal due to the presence of various manufacturing errors. This study aims at enhancing the models for planet load sharing through a three-dimensional formulation of N-planet helical planetary gear sets. Apart from previous models, the proposed model employs a gear mesh load distribution model to capture load and time dependency of the gear meshes iteratively. It includes all three types of manufacturing errors, namely constant errors such as planet pinhole position errors and pinhole diameter errors, constant but assembly dependent errors such as nominal planet tooth thickness errors, planet bore diameter errors, and rotation and assembly dependent errors such as gear eccentricities and run-outs. At the end, the model is used to show combined influence of these errors on planet load sharing to aid designers on how to account for manufacturing tolerances in the design of the gears of a planetary gear set.

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