Mesh Phasing Relations of General Compound Planetary Gears

2007 ◽  
Author(s):  
Yichao Guo ◽  
Robert G. Parker
Keyword(s):  
Dynamic Analysis ◽  
Planetary Gear ◽  
Phase Relations ◽  
Time Varying ◽  
Planetary Gears ◽  
Mesh Phasing ◽  
Gear Meshes

This paper systematically studies the mesh phase relations of general compound planetary gears. The mesh phase relations are described by the relative phases between mesh tooth variation functions of all gear meshes. The analysis allows for the fact that compound planetary gears may have gear meshes with different mesh periods. A numbering method is proposed for the accurate definitions of the relative phases in a general compound planetary gear. The phases of all gear meshes relative to the base referred mesh are calculated analytically. Important relations among these relative phases are also studied. The results from this study are important for the clarification of the mesh phasing properties of general compound planetary gears, and they are necessary for the dynamic analysis of compound planetary gears, which involves time-varying mesh stiffnesses.

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.

Optimization of Profile Modifications With Regard to Dynamic Tooth Loads in Single and Double-Helical Planetary Gears With Flexible Ring-Gears

2015 ◽  
Vol 138 (2) ◽  
Author(s):  
M. Chapron ◽  
P. Velex ◽  
J. Bruyère ◽  
S. Becquerelle
Keyword(s):  
Equations Of Motion ◽  
Integration Scheme ◽  
Time Varying ◽  
Time Step ◽  
Planetary Gears ◽  
Contact Algorithm ◽  
Beam Elements ◽  
Internal Gear ◽  
Gear Meshes ◽  
Optimum Profile

This paper is mostly aimed at analyzing optimum profile modifications (PMs) in planetary gears (PGTs) with regard to dynamic mesh forces. To this end, a dynamic model is presented based on 3D two-node gear elements connected to deformable ring-gears discretized into beam elements. Double-helical gears are simulated as two gear elements of opposite hands which are linked by shaft elements. Symmetric tip relief on external and internal gear meshes are introduced as time-varying normal deviations along the lines of contact and time-varying mesh stiffness functions are deduced from Wrinckler foundation models. The equations of motion are solved by coupling a Newmark time-step integration scheme and a contact algorithm to account for possible partial or total contact losses. Symmetric linear PMs for helical and double-helical PGTs are optimized by using a genetic algorithm with the objective of minimizing dynamic tooth loads over a speed range. Finally, the sensitivity of these optimum PMs to speed and load is analyzed.

Effect of Ring-Planet Mesh Phasing and Contact Ratio on the Parametric Instabilities of a Planetary Gear Ring

2007 ◽  
Vol 130 (1) ◽  
Author(s):  
Sripathi Vangipuram Canchi ◽  
Robert G. Parker
Keyword(s):  
Parametric Excitation ◽  
Planetary Gear ◽  
Time Varying ◽  
Ring Gear ◽  
Contact Ratio ◽  
System Parameters ◽  
Gear Ring ◽  
Parametric Instabilities ◽  
Planetary Gear System ◽  
Mesh Phasing

Parametric excitation of a rotating ring subject to moving time-varying stiffnesses has previously been investigated and given as closed-form expressions in the system parameters. These conditions are applied to identify ring gear parametric instabilities in a planetary gear system. Certain mesh phasing and contact ratio conditions suppress parametric instabilities, and these conditions are presented with examples.

scholarly journals An Improved Rigid Multibody Model for the Dynamic Analysis of the Planetary Gearbox in a Wind Turbine

2016 ◽  
Vol 2016 ◽  
pp. 1-18 ◽  
Author(s):  
Wenguang Yang ◽  
Dongxiang Jiang
Keyword(s):  
Dynamic Analysis ◽  
Transient Analysis ◽  
Planetary Gear ◽  
Time Varying ◽  
Mesh Stiffness ◽  
Vibration Signals ◽  
Planetary Gearbox ◽  
Multibody Model ◽  
Improved Model ◽  
Rigid Multibody

This paper proposes an improved rigid multibody model for the dynamic analysis of the planetary gearbox in a wind turbine. The improvements mainly include choosing the inertia frame as the reference frame of the carrier, the ring, and the sun and adding a new degree of freedom for each planet. An element assembly method is introduced to build the model, and a time-varying mesh stiffness model is presented. A planetary gear study case is employed to verify the validity of the improved model. Comparisons between the improvement model and the traditional model show that the natural characteristics are very close; the improved model can obtain the right equivalent moment of inertia of the planetary gear in the transient simulation, and all the rotation speeds satisfy the transmission relationships well; harmonic resonance and resonance modulation phenomena can be found in their vibration signals. The improved model is applied in a multistage gearbox dynamics analysis to reveal the prospects of the model. Modal analysis and transient analysis with and without time-varying mesh stiffness considered are conducted. The rotation speeds from the transient analysis are consistent with the theory, and resonance modulation can be found in the vibration signals.

Dynamic analysis for a planetary gear with time-varying pressure angles and contact ratios

2012 ◽  
Vol 331 (4) ◽  
pp. 883-901 ◽  
Author(s):  
Woohyung Kim ◽  
Ji Yeong Lee ◽  
Jintai Chung
Keyword(s):  
Dynamic Analysis ◽  
Planetary Gear ◽  
Time Varying

A Load Distribution Model for Planetary Gear Sets

2017 ◽  
Author(s):  
Yong Hu ◽  
David Talbot ◽  
Ahmet Kahraman
Keyword(s):  
Load Distribution ◽  
Planetary Gear ◽  
Distribution Model ◽  
Component Level ◽  
Gear Mesh ◽  
Position Errors ◽  
Unequally Spaced ◽  
Planetary Gear Sets ◽  
Mesh Phasing ◽  
Gear Meshes

Here, a load distribution model of planetary gear sets is presented capable of dealing with planetary gear sets with any component level and gear set level design variations such as component supporting conditions, different kinds of gear modifications and planetary gear sets with different numbers of equally or unequally spaced planets as well as different gear set kinematic configurations while considering gear mesh phasing. It also accounts for classes of planetary gear set manufacturing and assembly related errors associated with the carrier or gears, i.e. pinhole position errors, run-out errors and tooth thickness errors. Example analyses are provided to indicate the need for a model of this type when studying load distribution of planetary gear sets due to unique loading of the gear meshes associated with planetary gear sets. Comparisons to measurements existing in the literature are provided.

Vibration Resonances in a Planetary Gear Ring: Effects of Mesh Phasing and Contact Ratio

2007 ◽  
Author(s):  
Sripathi Vangipuram Canchi ◽  
Robert G. Parker
Keyword(s):  
Parametric Excitation ◽  
Planetary Gear ◽  
Time Varying ◽  
Ring Gear ◽  
Contact Ratio ◽  
System Parameters ◽  
Gear Ring ◽  
Parametric Instabilities ◽  
Planetary Gear System ◽  
Mesh Phasing

Parametric excitation of a rotating ring subject to moving time-varying stiffnesses have previously been investigated and given as closed form expressions in the system parameters. These conditions are applied to identify ring gear parametric instabilities in a planetary gear system. Certain mesh phasing and contact ratio conditions suppress parametric instabilities, and these conditions are presented with examples.

scholarly journals Mathematical Modeling and Dynamic Analysis of Planetary Gears System with Time-Varying Parameters

2020 ◽  
Vol 2020 ◽  
pp. 1-9
Author(s):  
Zhengming Xiao ◽  
Jinxin Cao ◽  
Yinxin Yu
Keyword(s):  
Gear Tooth ◽  
Planetary Gear ◽  
Time Varying ◽  
Tooth Root ◽  
Planetary Gears ◽  
Varying Parameters ◽  
Gear Dynamics ◽  
Gear Mesh ◽  
Time Varying Parameters ◽  
Root Crack

Planetary gears are widely used in automobiles, helicopters, heavy machinery, etc., due to the high speed reductions in compact spaces; however, the gear fault and early damage induced by the vibration of planetary gears remains a key concern. The time-varying parameters have a vital influence on dynamic performance and reliability of the gearbox. An analytical model is proposed to investigate the effect of gear tooth crack on the gear mesh stiffness, and then the dynamical model of the planetary gears with time-varying parameters is established. The natural characteristics of the transmission system are calculated, and the dynamic responses of transmission components, as well as dynamic meshing force of each pair of gear are investigated based on varying internal excitations induced by time-varying parameters and tooth root crack. The effects of gear tooth root crack size on the planetary gear dynamics are simulated, and the mapping rules between damage degree and gear dynamics are revealed. In order to verify the theoretical model and simulation results, the planetary gear test rig was built by assembling faulty and healthy gear separately. The failure mechanism and dynamic characteristics of the planetary gears with tooth root crack are clarified by comparing the analytical results and experimental data.

A Load Distribution Model for Planetary Gear Sets

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Y. Hu ◽  
D. Talbot ◽  
A. Kahraman
Keyword(s):  
Load Distribution ◽  
Planetary Gear ◽  
System Level ◽  
Distribution Model ◽  
Gear Mesh ◽  
Position Errors ◽  
Unequally Spaced ◽  
Planetary Gear Sets ◽  
Mesh Phasing ◽  
Gear Meshes

A load distribution model of planetary gear sets presented is capable of simulating planetary gear sets having component- and system-level design variations such as component supporting conditions, different kinds of gear modifications and planetary gear sets with different numbers of equally or unequally spaced planets as well as different gear set kinematic configurations while considering gear mesh phasing. It also accounts for classes of planetary gear set manufacturing and assembly related errors associated with the carrier or gears, i.e., pinhole position errors, run-out errors, and tooth thickness errors. Example analyses are provided to indicate the need for a model of this type when studying load distribution of planetary gear sets due to unique loading of the gear meshes associated with planetary gear sets. Comparisons to measurements existing in the literature are provided.

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