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A systematic analysis of the dynamics of a helical face-gear system with 8 degree of freedom is performed in this study under complex excitation. The nonlinear dynamic system is solved by the Runge-Kutta method. The bifurcation and dynamic load characteristics of the system is identified from a series of diagrams. The effect of multi-factor on bifu...
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... MATEC Web of Conferences 770 7 radial force in x direction are applied to the helical pinion. Radial force in y direction, tangential force in z direction and axial force in x direction are applied to the face-gear. The elastic supported dynamic model of the helical facegear transmission system is built under those forces, as is shown in Fig. 2. In the model, k Ij (I=X, Y, Z, j=p, g) is the bearing stiffness; c Ij (I=X, Y, Z, j=p, g) is the bearing damping; b Ij (I=X, Y, Z, j=p, g) is the bearing backlash; K h is the mesh stiffness; c h is the mesh damping; f is the nonlinear friction coefficient; b h is the gear backlash; e(t) is the transmission errors and varies as a ...
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Citations
... Hu et al. [17][18][19] developed a coupling vibration lumped parameter dynamic model based on a single face-gear pair and studied the influences of the directional rotation radius, transmission error, load, clearance, and other factors on the dynamic response. Moreover, Liu et al. [20] investigated the dynamic characteristics of 8DOF helical face-gear transmission and discussed the chaotic motion and dynamic load characteristics through bifurcation diagrams, time history diagrams, phase diagrams, Poincaré diagrams, and dynamic load coefficient diagrams. Based on the lumped parameter theory, Dong et al. [21] gave a bending-torsion coupling dynamic model of face gear and studied the mathematical relationship between various factors and the dynamic response characteristics. ...
The concentric face-gear split-torque transmission system (CFGSTTS) is a new type of transmission that has significant applications in helicopter main gearboxes. To study the influence of various parameters on the dynamic characteristics of the CFGSTTS, a 23-degree-of-freedom translation-torsion nonlinear dynamic model was established based on the lumped parameter theory. The model includes tooth backlash, error excitation, time-varying meshing stiffness with meshing phase difference, meshing damping, and elastic support deformation. The excitation conditions for the time-varying meshing stiffness of face-gear pairs were calculated based on the strain energy theory. The bifurcation characteristics of the system with different parameters were obtained by the nonlinear dynamics numerical analysis method. The research shows that the system exhibits rich vibration response characteristics at different rotating speeds. The amplitude of the vibration displacement in the system bifurcation diagram increases significantly with the increase of the tooth backlash and input torque, whereas the amplitude decreases constantly with the increase of the meshing damping. The critical rotational speed at which chaotic motion occurs increases significantly with increasing input torque and damping ratio but decreases with increasing tooth backlash. The bearing clearance has a weak influence on the vibration displacement amplitude of the system and the speed range of chaotic motion.
... The modified transversetorsional model was established in the rotating Cartesian coordinates by using the lumped-parameter method; thus, the model was more accurate than the purely torsional model for describing the physical dynamics (Xiao et al., 2016). Liu et al. (2016) performed a systematic analysis of the dynamics of a helical face-gear system with 8 degrees of freedom under complex excitation. The nonlinear dynamic system was solved using the Runge-Kutta method. ...
... The bifurcation and dynamic load characteristics of the system were identified from a series of diagrams. The effect of multi-factor on the bifurcation diagrams was also analyzed (Liu et al., 2016). Cai and Lin (2017) presented a generalized nonlinear dy-namic model based on Lagrange Bond graphs to study the nonlinear dynamic characteristics of a curve-face gear drive, and indicated that the vibration response of the curve-face gear is more complex than that of the face gear due to the influence of external excitation (Cai and Lin, 2017). ...
A novel transmission with multistage face gears as the core component achieves variable speeds via differential gear shifting. Single/multistage coupled vibration models have been established in this study to derive the coupled vibration equation in order to accurately solve the load distribution between the meshing teeth and the vibration shock between the shifting stages in the transmission process, improve the transmission smoothness of the face gears during the shifting processing, suppress the resonance of face gears meshing, reduce the noise, and optimize the power transmission performance. The characterization relationships of the key parameters such as equivalent mass, rotational inertia, equivalent mesh stiffness, support stiffness, and meshing damping coefficient to dynamic characteristics were investigated. The linear and nonlinear dynamic characteristics of coupled vibration differential equations were solved. The influence rules of factors such as integrated transmission error, dynamic load, tooth surface friction, loading speed, and load on the transmission system were analyzed. The results of the study provide a theoretical basis for the expansion of field of application of transmission devices.
A face-gear drive system has been extensively used in important transmission devices with strict requirements for size and weight such as helicopter reducer and so on. Its dynamic characteristics directly affect the stability and reliability of the equipment. A piecewise torsional-bending-pendular nonlinear dynamics model of the face-gear drive system is established to study its nonlinear dynamics and dynamic characteristics. The multi-state engagements including drive-side teeth engaging, teeth disengagement, back-side teeth engaging, and alternate engaging between single-teeth pair and double-teeth pairs caused by the couple of the backlash and the contact ratio being greater than 1.0 is considered. The change of the dynamic engaging force and load distribution ratio for the system is analyzed by numerical results under three different states engagement. The effects of the load coefficient, meshing frequency and the comprehensive transmission error on the dynamic characteristics and nonlinear dynamics of the system are studied based on three different Poincaré mappings defined by bifurcation diagrams, top Lyapunov exponent diagrams, phase portraits and variation curve of the dynamic engaging force. Results show that the complex phenomena such as teeth disengagement, drive-side and back-side impact occur with alternating meshing of the single and double pair teeth via the change of studied parameters. The research is helpful for the optimization of the face-gear drives.
