Condition Monitoring of Motor-Gear System Dynamics With Rotor and Gear Faults

2020 ◽  
Vol 15 (11) ◽  
Author(s):  
Wenyu Bai ◽  
Guanjun Bao ◽  
Datong Qin ◽  
Yawen Wang ◽  
Teik C. Lim
Keyword(s):  
Condition Monitoring ◽  
Planetary Gear ◽  
Response Spectra ◽  
Rotational Frequency ◽  
Gear System ◽  
Electromechanical System ◽  
Gear Mesh ◽  
Dynamic Eccentricity ◽  
Mechanical Faults ◽  
Slip Frequency

Abstract An electromechanical system consisting of an electric motor and planetary gear set is modeled and analyzed in this paper. The model integrates various internal excitations including time-varying gear mesh stiffness, nonlinear spatial effect and, saturation effect, and component flaws. The simulation results predict the effects of rotor and gear faults including broken rotor bar, rotor static and dynamic eccentricity, and tooth root crack of the gear on the electromechanical system behavior. It is verified as the results obtained are in accordance with the features derived within previous researches. Furthermore, new sidebands merged on the dynamic response spectra such as slip frequency harmonics, rotor rotational frequency harmonics, and fault-related rotational frequency harmonics can be applied to detect electrical and mechanical faults in the motor-gear system. This paper lays the foundation for the comprehensive further study of working condition monitoring for the motor-gear system.

Torsional Vibrations and Dynamic Loads in a Basic Planetary Gear System

1986 ◽  
Vol 108 (3) ◽  
pp. 348-353 ◽  
Author(s):  
R. August ◽  
R. Kasuba
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear System ◽  
Dynamic Loads ◽  
Ring Gear ◽  
Gear Mesh ◽  
Input And Output ◽  
Planetary Gear System ◽  
Three Degrees Of Freedom

An interative method has been developed for analyzing dynamic loads in a light weight basic planetary gear system. The effects of fixed, semi-floating, and fully-floating sun gear conditions have been emphasized. The load dependent variable gear mesh stiffnesses were incorporated into a practical torsional dynamic model of a planetary gear system. The dynamic model consists of input and output units, shafts, and a planetary train. In this model, the sun gear has three degrees of freedom; two transverse and one rotational. The planets, ring gear, and the input and output units have one degree of freedom, (rotation) thus giving a total of nine degrees of freedoms for the basic system. The ring gear has a continuous radial support. The results indicate that the fixed sun gear arrangement with accurate or errorless gearing offers in general better performance than the floating sun gear system.

scholarly journals Detection and Localization of Tooth Breakage Fault on Wind Turbine Planetary Gear System considering Gear Manufacturing Errors

2014 ◽  
Vol 2014 ◽  
pp. 1-13 ◽  
Author(s):  
Y. Gui ◽  
Q. K. Han ◽  
Z. Li ◽  
F. L. Chu
Keyword(s):  
Planetary Gear ◽  
Response Spectra ◽  
Gear System ◽  
Lumped Parameter Model ◽  
Lumped Parameter ◽  
Manufacturing Errors ◽  
Gear Manufacturing ◽  
Planetary Gear System ◽  
Planetary Gear Box ◽  
Detection And Localization

Sidebands of vibration spectrum are sensitive to the fault degree and have been proved to be useful for tooth fault detection and localization. However, the amplitude and frequency modulation due to manufacturing errors (which are inevitable in actual planetary gear system) lead to much more complex sidebands. Thus, in the paper, a lumped parameter model for a typical planetary gear system with various types of errors is established. In the model, the influences of tooth faults on time-varying mesh stiffness and tooth impact force are derived analytically. Numerical methods are then utilized to obtain the response spectra of the system with tooth faults with and without errors. Three system components (including sun, planet, and ring gears) with tooth faults are considered in the discussion, respectively. Through detailed comparisons of spectral sidebands, fault characteristic frequencies of the system are acquired. Dynamic experiments on a planetary gear-box test rig are carried out to verify the simulation results and these results are of great significances for the detection and localization of tooth faults in wind turbines.

An analyzing method of coupled modes in multi-stage planetary gear system

2014 ◽  
Vol 15 (11) ◽  
pp. 2357-2366 ◽  
Author(s):  
Wei Sun ◽  
Xin Ding ◽  
Jing Wei ◽  
Xinglong Hu ◽  
Qingguo Wang
Keyword(s):  
Planetary Gear ◽  
Gear System ◽  
Coupled Modes ◽  
Multi Stage ◽  
Planetary Gear System

Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

2015 ◽  
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.

Analysis of nonlinear dynamic characteristic of a planetary gear system considering tooth surface friction

2021 ◽  
pp. 135065012199174
Author(s):  
Jingyue Wang ◽  
Ning Liu ◽  
Haotian Wang ◽  
Jiaqiang E
Keyword(s):  
Damping Ratio ◽  
Excitation Frequency ◽  
Planetary Gear ◽  
Gear System ◽  
Tooth Surface ◽  
Lumped Mass ◽  
Heavy Load ◽  
Light Load ◽  
Planetary Gear System ◽  
Bifurcation Behavior

Based on the lumped mass method, a torsional vibration model of the planetary gear system is established considering the nonlinear factors such as friction, time-varying meshing stiffness, backlash, and comprehensive error. The Runge–Kutta numerical method is used to analyze the motion characteristics of the system with various parameters and the influence of tooth friction on the bifurcation and chaos characteristics of the system. The numerical simulation results show that the system has rich bifurcation behavior with the excitation frequency, damping ratio, comprehensive error amplitude, load and backlash, and experiences multiple periodic motion and chaotic motion. Tooth friction makes the bifurcation behavior of the system fuzzy in the high frequency and heavy load areas, makes the chaos of the system restrained in the low-damping ratio and light load areas, advances the bifurcation point of the system in the small comprehensive error amplitude area, and makes the period window of the chaos area larger in the large-backlash area, which makes the bifurcation behavior of the system more complex.

Dynamic Model Development of Wind Turbine Drivetrains by Using Sensor Measurements

2021 ◽  
Author(s):  
Diederik van Binsbergen ◽  
Amir R. Nejad ◽  
Jan Helsen
Keyword(s):  
Wind Turbine ◽  
Angular Displacement ◽  
Model Development ◽  
Rotational Frequency ◽  
Sensor Data ◽  
Gear Mesh ◽  
Modal Properties ◽  
Vibration Sensors ◽  
Displacement Sensors ◽  
Simulation Based

Abstract This paper aims to analyze the feasibility of establishing a dynamic drivetrain model from condition monitoring measurements. In this study SCADA data and further sensor data is analyzed from a 1.5MW wind turbine, provided by the National Renewable Energy Laboratory. A multibody model of the drivetrain is made and simulation based sensors are placed on bearings to look at the possibility to obtain geometrical and modal properties from simulation based vibration sensors. Results show that the axial proxy sensor did not provide any usable system information due to its application purpose. SCADA data did not meet the Nyquist frequency and cannot be used to determine geometrical or modal properties. Strain gauges on the shaft can provide the shaft rotational frequency, while torque and angular displacement sensors can provide the torsional eigenfrequency of the system. Simulation based vibration sensors are able to capture gear mesh frequencies, harmonics, sideband frequencies and shaft rotational frequencies.

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.

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.

scholarly journals Comparison of Electrical and Vibration Analysis Methods for Mechanical Fault Monitoring in Wind Turbine Drivetrains

2019 ◽  
Vol 9 (1) ◽  
pp. 2-7
Author(s):  
P Granjon ◽  
P D Longhitano ◽  
A Singh
Keyword(s):  
Wind Turbine ◽  
Vibration Analysis ◽  
Wind Farm ◽  
Electromechanical System ◽  
Main Bearing ◽  
Monitoring Method ◽  
Fault Monitoring ◽  
Three Phase ◽  
Mechanical Faults ◽  
Electrical Generator

Mechanical faults occurring in drivetrains are traditionally monitored through vibration analysis and, more rarely, by analysing electrical quantities measured on the electromechanical system involved. However, a monitoring method that is able to take into account all of the information contained in three-phase electrical quantities was recently proposed. The goal of this paper is to compare this threephase electrical approach with the usual vibration-based method in terms of its capability to detect mechanical faults in drivetrains. In this context, a 2 MW geared wind turbine operating in an industrial wind farm was equipped with accelerometers near the main bearing and electrical sensors on the stator of the electrical generator for several months. During this period, an important mechanical fault occurred in the main bearing of the system. The evolution of the fault indicators computed by the two previous approaches were compared throughout this period of time. All of the indicators behaved similarly and showed the development of an inner bearing fault in the main bearing. This demonstrated that a mechanical fault occurring in a drivetrain can be monitored and detected by analysing electrical quantities, even if the fault is located some distance from the electrical generator.

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