scholarly journals Vibration Characteristics Analysis of Planetary Gears with a Multi-Clearance Coupling in Space Mechanism

Energies ◽  
2018 ◽  
Vol 11 (10) ◽  
pp. 2687 ◽  
Author(s):  
Huibo Zhang ◽  
Chaoqun Qi ◽  
Jizhuang Fan ◽  
Shijie Dai ◽  
Bindi You
Keyword(s):  
Rotational Velocity ◽  
Dynamic Performance ◽  
Planetary Gear ◽  
Vibration Characteristics ◽  
Radial Clearance ◽  
Nonlinear Dynamic Model ◽  
Planetary Gears ◽  
Light Load ◽  
Characteristics Analysis ◽  
Gear Systems

Multi-clearance is the main cause for the performance and reliability decline of complicated mechanical systems. The increased clearance could induce contacts and impacts in joints, and consequently affect control accuracy. A nonlinear dynamic model of planetary gears with multi-clearance coupling is proposed in the current study to investigate the mechanism of influence of clearance on the dynamic performance. In addition, the coupling relationship between radial clearance and backlash is integrated into the multi-body system dynamics. The vibration characteristics of planetary gears with the changes of rotational velocity, clearance size and inertia load are explored. The numerical simulation results show that there are complex coupling relations in planetary gear systems, due to the multi-clearance coupling. The phenomenon of system resonance may occur with the changes of rotational velocities and clearances’ sizes. Multi-clearance coupling can significantly increase the resonant response of planetary gear systems in empty-load or light-load states.

scholarly journals Dynamic Analysis of Planetary Gear Train Based on ADAMS

2018 ◽  
Vol 175 ◽  
pp. 03051
Author(s):  
Yongliang Yuan
Keyword(s):  
Dynamic Performance ◽  
Reference Value ◽  
Planetary Gear ◽  
Gear Train ◽  
Automatic Assembly ◽  
Electronic Industry ◽  
Planetary Gears ◽  
Planetary Gear Trains ◽  
Planet Gear ◽  
Gear Trains

Automatic pin machine is a kind of typical equipment widely used in mechanical and electronic industry, which is mainly used for automatic assembly of pinhole parts. In order to improve the efficiency and stability of the transmission system, the dynamic performance of planetary gears is studied. This paper uses UG to establish the dynamic model of planetary gears. Dynamic simulation and its motion law are obtained using Adams. The contact force between the planet gear and the center gear fluctuates around 5000N, and increases with the load. The results show that Adams can provide an effective prediction of the dynamic characteristics of planetary gear trains, and have a certain reference value for future structural improvements.

scholarly journals Dynamic Performance of Planetary Gear Joint for Satellite Antenna Driving Mechanism Considering Multi-Clearance Coupling

Energies ◽  
2021 ◽  
Vol 14 (4) ◽  
pp. 815
Author(s):  
Jianchao Han ◽  
Lei Liang ◽  
Yang Zhao
Keyword(s):  
Coupling Effect ◽  
Dynamic Performance ◽  
Planetary Gear ◽  
Analytical Models ◽  
Radial Clearance ◽  
Driving Mechanism ◽  
Tracking Accuracy ◽  
Satellite Antenna ◽  
Dynamic Errors ◽  
Stiffness And Damping

Dynamic pointing and tracking accuracy are the most relevant indicators of dynamic performance for the satellite antenna driving mechanism. Multi-clearance coupling in the joints will incur high-frequency vibration and dynamic errors of the system. Joints of existing analytical models are generally oversimplified as planar revolute hinges, which ignore the coupling effect of multi-clearance. It cannot proficiently predict the dynamic behavior of the driving mechanism with multi-clearance on the orbit. To address this problem, a typical 2K-H planetary gear joint model with multi-clearance coupling has been developed by considering radial clearance, backlash, tooth profile error, time-varying meshing stiffness, and damping. A dynamic model of a typical dual-axis driving mechanism is established to analyze the dynamic characteristics of multibody systems with planetary gear joints. The effects of rotational speed, radial clearance, backlash, and their coupling on the dynamic performance of the dual-axis driving mechanism under different driving modes are explored by numerical simulations. The results show that the coupling of radial clearance and backlash in joints have a significant influence on the dynamic performance of the system. Appropriate clearance design avails the dynamic pointing accuracy and tracking accuracy of the dual-axis driving mechanism.

scholarly journals Simulative investigation of ring creep on a planetary bearing of a wind turbine gearbox

2021 ◽  
Author(s):  
Jonas Gnauert ◽  
Felix Schlüter ◽  
Georg Jacobs ◽  
Dennis Bosse ◽  
Stefan Witter
Keyword(s):  
Experimental Data ◽  
Finite Element Method ◽  
Sensitivity Analysis ◽  
Planetary Gear ◽  
The Finite Element Method ◽  
Relative Movement ◽  
Wind Turbine Gearbox ◽  
Interference Fit ◽  
Planetary Gears ◽  
Module Coefficient

AbstractWind turbines (WT) must be further optimized concerning availability and reliability. One of the major reasons of WT downtime is the failure of gearbox bearings. Some of these failures occur, due to the ring creep phenomenon, which is mostly detected in the planetary bearings. The ring creep phenomenon describes a relative movement of the outer ring to the planetary gear. In order to improve the understanding of ring creep, the finite element method (FEM) is used to simulate ring creep in planetary gears. First, a sensitivity analysis is carried out on a small bearing size (NU205), to characterize relevant influence parameters for ring creep—considered parameters are teeth module, coefficient of friction, interference fit and normal tooth forces. Secondly, a full-scale planetary bearing (SL185030) of a 1MW WT is simulated and verified with experimental data.

Dynamic Analysis of Planetary Gear Reducer

2018 ◽  
Vol 880 ◽  
pp. 87-92
Author(s):  
Daniela Vintilă ◽  
Laura Diana Grigorie ◽  
Alina Elena Romanescu
Keyword(s):  
Finite Elements ◽  
Differential Equations ◽  
Dynamic Analysis ◽  
Frequency Response ◽  
Planetary Gear ◽  
Resonance Phenomenon ◽  
Superposition Method ◽  
Planetary Gears ◽  
Tower Crane ◽  
Systems Of Differential Equations

This paper presents dynamic analysis of a three stage planetary gear reducer for operate a tower crane. Ordinary and planetary gears have been designed respecting the coaxial, neighboring and mounting conditions. Harmonic analysis has been processed to identify frequency response for displacements, strains and deformations. The aim of the study was to determine critical frequencies to avoid mechanical resonance phenomenon. The obtained results are based on the superposition method for solving the systems of differential equations resulting from the analysis with finite elements.

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 Characteristics Analysis for the Headstock of a Vertical Machining Center

2016 ◽  
Vol 836-837 ◽  
pp. 348-358
Author(s):  
Zhe Li ◽  
Song Zhang ◽  
Yan Chen ◽  
Peng Wang ◽  
Ai Rong Zhang
Keyword(s):  
Dynamic Characteristics ◽  
Natural Frequencies ◽  
Vibration Characteristics ◽  
Numerical Control ◽  
Vibration Test ◽  
Machining Accuracy ◽  
Modal Test ◽  
Machining Center ◽  
Characteristics Analysis ◽  
Nc Machine

Dynamic characteristics of numerical control (NC) machine tools, such as natural frequency and vibration property, directly affect machining efficiency and finished surface quality. In general, low-order natural frequencies of critical components have significant influences on machine tool’s performances. The headstock is the most important component of the machine tool. The reliability, cutting stability, and machining accuracy of a machining center largely depend on the structure and dynamic characteristics of the headstock. First, in order to obtain the natural frequencies and vibration characteristics of the headstock of a vertical machining center, modal test and vibration test in free running and cutting conditions were carried out by means of the dynamic signal collection and analysis system. According to the modal test, the first six natural frequencies of the headstock were obtained, which can not only guide the working speed, but also act as the reference of structural optimization aiming at frequency-shift. Secondly, by means of the vibration test, the vibration characteristics of the headstock were obtained and the main vibration sources were found out. Finally the corresponding vibration reduction plans were proposed in this paper. That provides the reference for improving the performance of the overall unit.

scholarly journals Reliability and Random Lifetime Models of Planetary Gear Systems

2018 ◽  
Vol 2018 ◽  
pp. 1-12 ◽  
Author(s):  
Peng Gao ◽  
Liyang Xie ◽  
Wei Hu
Keyword(s):  
Load Distribution ◽  
Planetary Gear ◽  
Working Process ◽  
Random Load ◽  
Working Mechanism ◽  
Dynamic Reliability ◽  
Reliability Models ◽  
Process Failure ◽  
Failure Dependence ◽  
Gear Systems

Conventional reliability models of planetary gear systems are mainly static. In this paper, dynamic reliability models and random lifetime models of planetary gear systems are developed with dynamic working mechanism considered. The load parameters, the geometric parameters, and the material parameters are taken as the inputs of the reliability models and the random lifetime models. Moreover, failure dependence and dynamic random load redistributions are taken into account in the models. Monte Carlo simulations are carried out to validate the proposed models. The results show that the randomness of the load distribution is obvious in the system working process. Failure dependence has significant influences on system reliability. Moreover, the dispersion of external load has great impacts on the reliability, lifetime distribution, and redundancy of planetary gear systems.

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