scholarly journals Dynamic analysis of traction motor in a locomotive considering surface waviness on races of a motor bearing

Author(s):  
Yuqing Liu ◽  
Zaigang Chen ◽  
Wei Li ◽  
Kaiyun Wang

AbstractThe traction motor is the power source of the locomotive. If the surface waviness occurs on the races of the motor bearing, it will cause abnormal vibration and noise, accelerate fatigue and wear, and seriously affect the stability and safety of the traction power transmission. In this paper, an excitation model coupling the time-varying displacement and contact stiffness excitations is adopted to investigate the effect of the surface waviness of the motor bearing on the traction motor under the excitation from the locomotive-track coupled system. The detailed mechanical power transmission path and the internal/external excitations (e.g., wheel–rail interaction, gear mesh, and internal interactions of the rolling bearing) of the locomotive are comprehensively considered to provide accurate dynamic loads for the traction motor. Effects of the wavenumber and amplitude of the surface waviness on the traction motor and its neighbor components of the locomotive are investigated. The results indicate that controlling the amplitude of the waviness and avoiding the wavenumber being an integer multiple of the number of the rollers are helpful for reducing the abnormal vibration and noise of the traction motor.

Energies ◽  
2021 ◽  
Vol 14 (18) ◽  
pp. 5810
Author(s):  
Bingbin Guo ◽  
Zhixiang Luo ◽  
Bo Zhang ◽  
Yuqing Liu ◽  
Zaigang Chen

Wheel flat can cause a large impact between the wheel and rail and excites a forced vibration in the locomotive and track structure systems. The working conditions and fatigue life of the motor bearings are significantly affected by the intensified wheel–rail interaction via the transmission path of the gear mesh. In this study, a fatigue life prediction method of the traction motor bearings in a locomotive is proposed. Based on the L−P theory or ISO 281 combined with the Miner linear damage theory and vehicle–track coupled dynamics, the irregular loads induced by the track random irregularity and gear mesh are considered in this proposed method. It can greatly increase the accuracy of predictions compared with the traditional prediction models of a rolling bearing life whose bearing loads are assumed to be constant. The results indicate that the periodic impact forces and larger mesh forces caused by the wheel flat will reduce the fatigue life of the motor bearings, especially when the flat length is larger than 30 mm. Using this method, the effects of the flat length and relatively constant velocity of the locomotive are analyzed. The proposed method can provide a theoretical basis to guarantee safe and reliable working for motor bearings.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Yanwei Xu ◽  
Weiwei Cai ◽  
Tancheng Xie

Under the variable working condition, the fault signal of the rolling bearing contains rich characteristic information. In view of the problem that the traditional fault diagnosis method of the rolling bearing depends on the prior knowledge and expert experience too much and the low recognition rate of some faults with the single signal, one method of rolling bearing fault diagnosis based on information fusion under the variable working condition is proposed. Firstly, one test and multi-information acquisition system of the rolling bearing is built. Secondly, the metro traction motor bearing nu216 is selected as the research object, and to prefabricate the defects, the data of acoustic emission and vibration acceleration signals during the test of the bearing is acquired. Then, the original signal is processed and extracted by the wavelet packet decomposition, and the normalized feature information is fused by the convolution neural network. Finally, the two-dimensional convolution neural network model is established to diagnose the bearing fault of the metro traction motor under different conditions. The test results show that the intelligent fault diagnosis method of the subway traction motor bearing based on information fusion under variable working conditions can accurately identify the fault type of the bearing, while the load and speed change. When the neural network training set and the test set cover the same working conditions, the accuracy can reach 100%.


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Tingting Wang ◽  
Dongli Song ◽  
Weihua Zhang ◽  
Shiqi Jiang ◽  
Zhiwei Wang

Purpose The purpose of this paper is to analyze the unbalanced magnetic pull (UMP) of the rotor of traction motor and the influence of the UMP on thermal characteristics of traction motor bearing. Design/methodology/approach The unbalanced magnetic pull on the rotor with different eccentricity was calculated by Fourier series expansion method. A bearing thermal analysis finite element model considering both the vibration of high-speed train caused by track irregularity and the UMP of traction motor rotor was established. The validity of the model is verified by experimental data obtained from a service high-speed train. Findings The results show that thermal failure of bearing subassemblies most likely occurs at contact area between the inner ring and rollers. The UMP of rotor of traction motor has a significant effect on the temperature of the inner ring and roller of the bearing. When the eccentricity is 10%, the temperature can even be increased by about 12°C. Therefore, the UMP of rotor of traction motor must be considered in thermal analysis of traction motor bearing. Originality/value In the thermal analysis of the bearing of the traction motor of high-speed train, the UMP of the rotor of the traction motor is considered for the first time


Author(s):  
Minjie Sun ◽  
Haojie Xu ◽  
Qi An

Raceway waviness error is the main reason to cause rolling elements to vibrate along axial direction and emit noise. In this paper, the mechanical analysis on deep groove ball bearing is carried out. With auto-correlation function, random surface waviness of both inner and outer raceways is simulated. A contact model of rolling elements and raceways considering surface waviness is established. Combining with the theory of acoustic equation, a calculation model is established for the noise caused by vibration of rolling elements and inner ring. The results show that with the decrease of machining accuracy, the noise of rolling elements increases due to axial vibration; with the increase of rotation speed, the noise also increases. Besides, the spectrum of radiation noise of inner raceway with different waviness amplitudes is given. The results indicate that the 3-D waviness on raceway surface has an influence on the vibration and the noise emitted by both rolling elements and inner ring, and provide guidance for sound control in deep groove rolling bearing.


2019 ◽  
Vol 60 (4) ◽  
pp. 256-261
Author(s):  
Yo SAKAIDANI ◽  
Minoru KONDO ◽  
Ken TAKAHASHI

Processes ◽  
2020 ◽  
Vol 8 (5) ◽  
pp. 606
Author(s):  
Hassane Hotait ◽  
Xavier Chiementin ◽  
Lanto Rasolofondraibe

Bearings are essential components in rotating machines. They ensure the rotation and power transmission. So, these components are essential elements for industrial machines. Thus, real-time monitoring is required to detect a possible anomaly, diagnose the failure of rolling bearing and follow its evolution. This paper presents a methodology for automatic online implementation of fault diagnosis of rolling bearings, by AOC-OPTICS (automatic online classification monitoring based on ordering points to identify clustering structure, OPTICS). The algorithm consists of three phases namely: initialization, detection and follow-up. These phases use the combination of features extraction methods, smart ranking, features weighting and classification by the OPTICS method. Two methods have been integrated in the dimension reduction step to improve the efficiency of detection and the followed of the defect (relief method and t-distributed stochastic neighbor embedding method). Thus, the determination of the internal parameters of the OPTICS method is improved. A regression model and exponential model are used to track the fault. The analytical simulations discuss the influence of parameters automation. Experimental validation shows detection with 100% accuracy and regression models of monitoring reaching R 2 = 0.992 .


Author(s):  
Sidi M. Berri ◽  
J. M. Klosner

Abstract The present study is a combined experimental/analytical investigation of the effect of a cracked pinion tooth on the vibrational characteristics of a power transmission system. It is part of an ongoing effort to develop strategies for locating and quantifying local defects by properly processing and interpreting the output signals. Presented, is a system of nonlinear equations representing the analytical model of an experimental test rig. The model includes the effect of crack size on the time-varying gear mesh stiffness, and the equations are solved by using a Newmark-Beta numerical integration scheme. The numerically and experimentally obtained signals, processed by using the wavelet transform, show excellent agreement over a range of crack sizes and running speeds, thus suggesting that mathematical simulation can provide a useful tool for quantifying cracks.


Author(s):  
J. C. Collinger ◽  
W. C. Messner ◽  
J. A. Wickert

A novel vibration control method utilizing magnetically mounted piezoelectric actuators is described. Piezoelectric actuators are bonded to permanent magnets, which are attached to the surface of a steel cantilever beam through their magnetic attraction. The magnetic-piezoelectric control mounts are an alternative to traditional epoxy attachment methods for piezoelectrics which allows easy in-the-field reconfiguration. In model and laboratory measurements, the beam is driven through base excitation and the resonant shunt and synchronized switching techniques are applied to two magnetic-piezoelectric control mounts to attenuate vibration. The coupled system is discretized using a Galerkin finite element model that incorporates relative axial motion between the beam and the mounts, which is governed by the sticking contact stiffness per unit length of the beam-magnet interface. The control mounts are designed using a magnetic array configuration which increases the attraction force for a given magnet thickness. Results show that the magnetic-piezoelectric control mounts provide attenuation, while also providing the flexibility to easily adjust the actuators along the length of the beam.


2016 ◽  
Vol 24 (5) ◽  
pp. 924-936 ◽  
Author(s):  
Yuanyuan Zhang ◽  
Huaiju Liu ◽  
Caichao Zhu ◽  
Chaosheng Song ◽  
Zufeng Li

Stiffness properties of interfacial engineering surfaces are of great importance to the dynamic performance of relevant mechanical systems. Normal contact stiffness and oil film stiffness of line contact problems are studied in this work analytically and numerically. The Hertzian contact theory and the Yang–Sun method are applied to predict the contact stiffness, while the empirical elastohydrodynamic lubrication (EHL) film thickness method and the complete numerical EHL model are used to predict the oil film stiffness. The numerical model mainly consists of the Reynolds equation; the film thickness equation, in which the regular surface roughness is taken into consideration; the force balance equation; and the viscosity-pressure equation. The effects of the normal load, rolling speed, regular surface waviness, and starved lubrication level on the oil film stiffness are investigated.


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