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To develop accurate diagnostic techniques, this study examines the dynamic responses of spur gear transmission system with including frictional effects on a tooth mesh process. An 8-degree-of-freedom model is developed to include the effects of supporting bearings, a driving motor and a loading system. Moreover, it takes into account not only the t...
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The drive shaft arrangement has a considerable influence on the vibration responses of the shaft-final drive system. In this research, a coupled vibration model is developed based on force analysis of hypoid gear and lumped mass method. The effect of time-varying mesh stiffness, gear backlash and transfer error are included to investigate the effec...
Citations
... The paper also concluded that there is an increase in dynamic transmission error when sliding friction is not negligible. Brethee et al. 2016) investigated the spur gear power transmission system to study the effect of sliding friction. The model incorporated time-varying mesh stiffness, contact force, and moment arm into the model. ...
... The same natural frequencies are appearing in the sidebands and harmonics of the GMF's; however, the second natural frequency has greater modulating characteristics. This indicates that the sliding friction leads to more vibration characteristics of the gearbox assembly (He et al., 2007;Brethee et al., 2016;Jiang and Liu, 2017;Mo et al., 2018;Lundvall et al., 2004). The rotational deflection of each drivetrain component is also increasing with friction since some part of the energy is lost in overcoming the friction. ...
... Hence, the amount of sulphuric acid increases, and it causes decreases the TBN (total base number) and takes part in corrosion of the gear flank. [23][24][25] Peaks (absorbance) for sulfation, at wave no. 1200 cm À1 , oxidation at wave no. ...
... The hardness of the T A B L E 3 Absorbance % of attributes and its correlation with running days of machine. 25,29,30 with the running days of the machine is plotted in Figure 3 to understand the changes in tribological behaviour. COF is increasing with the running days of the machine. ...
The objective of this paper is to study the parameters that affect the remaining useful life of lubricant (RULL). Fourier-transform infrared spectroscopy (FTIR) of gear oil is used to observe the contamination in the oil. Coefficient of friction (COF) has been found out using pin on disc tribometer using gear oil, and simultaneously, wear debris has been collected. Particles distribution and elemental analysis of wear debris were observed by emission scanning electron microscopy (FESEM) Field with energy dispersive x-ray (EDX) respectively. Oxidation, sulfation, soot and water content in lubricant increase with time and decrease the RULL. ANOVA is applied to find out the most influential parameter for wear debris and found a load on gears is the dominating factor for wear. This method is the potential to monitor the root causes of contamination and change in lubricant properties and may help to detect the other early signs of failure.
... For example, Martin and Seabra[11] give a numerical computing result for friction coefficient in FZG meshing spur gears system, lubricated with industrial oil (ester), and in operating conditions, M= (50-200) Nm, n=2000 rpm, values between 0.015 and 0.025. Khaldoon et al. provide the same range of friction coefficient values[12].Another method of validating the results was to compute individual efficiency for gear transmission, bearings, and churning and compare it to literature values. We found an efficiency of 0.98-0.99 for the gear pair which matches the results of Pedrero [13] and Pleguezuelos[14]. ...
The goal of the research is to assess the power losses in a gearbox with helical gears. In addition, the effects of each component of the total power loss in a gear transmission system are investigated. The study shows the important influence of the gear meshing power loss and discuss some aspects concerning the calculus formula. Also, the coefficient of friction is computed and the efficiency of the gear meshing system and the bearing rolling pair. Results are compared to a numerical results obtained by other researchers.
... The TVMS is considered as the most important source of excitation which depends on the time varying point of meshing during the line of action (LOA). Several research works have given a great interest in its study in healthy and cracked cases [12][13][14][15]. ...
In the current work, the nonlinear dynamic behavior of an eight degrees of freedom gear system is investigated. Tooth crack is introduced into the model. The main sources of excitation are the time varying mesh stiffness (TVMS), time varying mesh damping, backlash and friction inter teeth. By using the potential energy method applied into the cantilevered beam, the TVMS is calculated. The backlash is considered as a dead zone. The effect of backlash, friction and tooth crack on the vibration frequencies is highlighted. The crack detection is based on the time-frequency analysis.
... Yi et al. [13] established a new nonlinear dynamic model considering time-varying behaviors of pressure angle and gear backlash. Chen et al. [14,15], Brethee et al. [16], Mohammed et al. [17], Jiang et al. [18], Ma et al. [19] performed dynamic modeling of gear transmission when gear faults were present. Kahraman et al. [20][21][22][23] in the gear research center of the Ohio State University performed a series of gear dynamics investigation experimentally and theoretically that offered good references for gear design. ...
There is no existing effective analytical method for calculating the mesh stiffness of spur gears with tooth root crack when the interactions between the neighboring teeth induced by gear body flexibility are considered, while this factor has been demonstrated to have a considerable effect on the mesh stiffness. In this paper, an improved method of spur gear mesh stiffness is proposed based on the theory of elastic mechanics for circular ring, which is capable of calculating the mesh stiffness with tooth root crack accurately. Then, the calculated gear body-induced stiffness results considering structural coupling effect with tooth root crack is validated by the finite element method. In addition, the effect of different hub hole radius and crack lengths on the stiffness caused by the structural coupling effect are investigated. The results indicate that the proposed analytical method is more accurate for spur gear mesh stiffness calculation with tooth root crack.
... 6 Brethee et al. considered the influence of friction on the dynamic response of gear system. 7 Existing literature points that transmission error is one of the main excitations that cause gear vibration and noise. Hjelm et al. studied the relationship between transmission error, contact pressure and manufacturing error tolerance. ...
The tooth profile crowning modification was applied onto paired gears for reducing the noise of an electric vehicle reducer. The simulated gear contact spots are compared before and after modification, and are validated by a contact spot experiment. Based on the rigid-flexible coupling model of the gear transmission system, the time-varying meshing stiffness, time-varying meshing force, and the vibration and noise of the gear pairs with different modified gears obtained by simulating calculation are analyzed. The results showed that the selection of modified gear has a great influence on the modification effect. In the way of tooth profile crowning, it is not advisable to modify the pinion independently, as it may increase the frequency and degree of meshing impact between the helical gear pair, making the transmission become less smooth; while modifying the wheel and pinion at the same time can effectively reduce the time-varying meshing stiffness and force, and the vibration and noise. Also, the optimized gear modification scheme is verified by the noise test.
... Yi et al. [13] established a new nonlinear dynamic model considering time-varying behaviors of pressure angle and gear backlash. Chen et al. [14,15], Brethee et al. [16], Mohammed et al. [17], Jiang et al. [18], Ma et al. [19] performed dynamic modeling of gear transmission when gear faults were present. Kahraman et al. [20][21][22][23] in the gear research center of the Ohio State University performed a series of gear dynamics investigation experimentally and theoretically that offered good references for gear design. ...
Gear tooth profile deviations are usually inevitable due to the application of intentional tooth profile modification, the existence of undesired gear manufacturing errors and the tooth surface defects during operation, and they have been demonstrated to have significant effect on the vibration and noise level of gear transmissions. How to calculate the gear mesh forces accurately is crucial for gear dynamic simulation, especially in the presence of gear tooth profile deviations that will complicate the interactions at the gear mesh interface. This paper presents a spur gear dynamic model where the detailed deformations of individual teeth are considered, including the tooth flexible deformations, gear body deformations, the local teeth contact deflections, and the tooth deformations due to its neighboring loaded tooth. This dynamic model is validated by experimental test results with and without tooth tip reliefs. Then, the optimization of the tooth tip relief is performed. Finally, it is compared with three traditional dynamic models to reveal their discrepancies and applicability which could supply theoretical guidance for selection of gear dynamic models.
... Moreover, certain coefficients in the equations are determined on the basis of stand research on samples, e.g. disc-shaped [17,18]. Considering the information above, it is to be stated that the obtained results are correct for the given parameter range [17,19]. ...
... disc-shaped [17,18]. Considering the information above, it is to be stated that the obtained results are correct for the given parameter range [17,19]. ...
... | 1 | = | 1 | sin = 1 sin (17) and similarly ...
The main objective of this paper is to investigate the influence of tooth friction on the dynamic force of the gearbox. This is one of the most insignificantly investigated aspects of the gearbox work, despite both experimental and theoretical research conducted. For this reason, it is not entirely possible to establish the friction force determining the friction coefficient due to the complexity of the process. Currently, various approaches are taken in calculating dynamic models, among others excluding friction, Coulomb models, models in which the value of the friction coefficient depends on the sliding velocity, and the application of complex elastohydrodynamic models. Due to such different approaches, it was decided to examine the influence of tooth friction on the dynamic force for the stationary work conditions of the gearbox. Moreover, a new gear tooth friction model was developed, based on the Coulomb model of friction and rolling friction. The results were obtained for four friction models and, in the fifth case, without including it. Furthermore, the influence of torsional vibration on the friction lever arm was analysed.
... Friction force variation has large fluctuation along gear meshing line, which is the main cause of excitation in gears. The effects of friction on meshing gears include nonlinear dependence of friction on the sliding velocity, and energy dissipation [17,18]. In general, frictional effects can be derived from elasto-hydrodynamic lubrication (EHL) and tribology theory, which is considered the dominant mode of lubrication accumulated with the gears meshing surfaces [19]. ...
... Friction force variation has large fluctuation along gear meshing line, which is the main cause of excitation in gears. The effects of friction on meshing gears include nonlinear dependence of friction on the sliding velocity, and energy dissipation [17,18]. In general, frictional effects can be derived from elasto-hydrodynamic lubrication (EHL) and tribology theory, which is considered the dominant mode of lubrication accumulated with the gears meshing surfaces [19]. ...
To develop online condition monitoring of lubrication characteristics, this research will investigate the effect of lubricant water contamination on the gearbox vibration signatures. A theoretical analysis is conducted to understand the changes of lubricant properties caused by added water content. Then it predicts how the change can alter the tribological behaviour of gear mesh process that can critically lead to changes in vibrations of gears. Moreover, experimental studies have obtained consistent results which allows for an indication of the lubrication performance, showing different degrees of water contamination. Gearbox vibration signal was analysed using modulation signal bispectrum (MSB) analysis, which has high performance in selecting modulation components and suppressing random noise. More accurate and reliable results were produced using this method for assisting and diagnosing lubricant condition.
