scholarly journals Natural Frequencies and Vibrating Modes for a Magnetic Planetary Gear Drive

2012 ◽  
Vol 19 (6) ◽  
pp. 1385-1401 ◽  
Author(s):  
Lizhong Xu ◽  
Xuejun Zhu
Keyword(s):  
Natural Frequencies ◽  
Planetary Gear ◽  
Drive System ◽  
Dynamic Equations ◽  
The Sun ◽  
System Parameters ◽  
Meshing Stiffness ◽  
Torsion Mode ◽  
Gear Drive ◽  
Pair Number

In this paper, a dynamic model for a magnetic planetary gear drive is proposed. Based on the model, the dynamic equations for the magnetic planetary gear drive are given. From the magnetic meshing forces and torques between the elements for the drive system, the tangent and radial magnetic meshing stiffness is obtained. Using these equations, the natural frequencies and the modes of the magnetic planetary gear drive are investigated. The sensitivity of the natural frequencies to the system parameters is discussed. Results show that the pole pair number and the air gap have obvious effects on the natural frequencies. For the planetary gear number larger than two, the vibrations of the drive system include the torsion mode of the center elements, the translation mode of the center elements, and the planet modes. For the planetary gear number equal to two, the planet mode does not occur, the crown mode and the sun gear mode occur.

scholarly journals Effects of Eccentricity on the Dynamic Behavior for Electromechanical Integrated Toroidal Drive

2013 ◽  
Vol 20 (2) ◽  
pp. 273-286 ◽  
Author(s):  
Lizhong Xu ◽  
Haifeng Li
Keyword(s):  
Dynamic Behavior ◽  
Natural Frequencies ◽  
Drive System ◽  
The Other ◽  
Dynamic Equations ◽  
Electromechanical Integrated ◽  
Drive Systems ◽  
Forced Responses ◽  
Design And Manufacture ◽  
Center Distance

In electromechanical integrated toroidal drive, eccentric center errors occur which has important influences on the dynamic behavior of the drive system. Here, the dynamic equations of the drive system with eccentric center are presented. Changes of the natural frequencies and vibrating modes along with eccentric center distance are analyzed. The forced responses of the drive system to eccentric center excitation are investigated. Results show that the eccentric center causes some natural frequencies to increase, and the other natural frequencies to drop. It also causes some vibrations to become weak, and the other vibrations to become strong. The eccentric center has more obvious effects on the dynamic behavior of the planets. The results are useful in design and manufacture of the drive systems.

Sensitivity of General Compound Planetary Gear Natural Frequencies and Vibration Modes to Model Parameters

2006 ◽  
Author(s):  
Yichao Guo ◽  
Robert G. Parker
Keyword(s):  
Natural Frequencies ◽  
Planetary Gear ◽  
Lumped Parameter Model ◽  
Model Parameters ◽  
Vibration Modes ◽  
Planetary Gears ◽  
System Parameters ◽  
Modal Properties ◽  
Mass Moment ◽  
Inertia Parameters

This paper studies sensitivity of compound planetary gear natural frequencies and vibration modes to system parameters. Based on a lumped parameter model of general compound planetary gears and their distinctive modal properties [1], the eigensensitivities to inertias and stiffnesses are calculated and expressed in compact formulae. Analysis reveals that eigenvalue sensitivities to stiffness parameters are directly proportional to modal strain energies, and eigenvalue sensitivities to inertia parameters are proportional to modal kinetic energies. Furthermore, the eigenvalue sensitivities to model parameters are determined by inspection of the modal strain and kinetic energy distributions. This provides an effective way to identify those parameters with the greatest impact on tuning certain natural frequencies. The present results, combined with the modal properties of general compound planetary gears, show that rotational modes are independent of translational bearing/shaft stiffnesses and masses of carriers/central gears, translational modes are independent of torsional bearing/shaft stiffnesses and moment of inertias of carriers/central gears, and planet modes are independent of all system parameters of other planet sets, the shaft/bearing stiffness parameters of carriers/rings, and the mass/moment of inertia parameters of carriers/central gears.

Grouping of Planetary Gear Modes With Significant Tooth Mesh Deflection

2012 ◽  
Author(s):  
Tristan M. Ericson ◽  
Robert G. Parker
Keyword(s):  
Natural Frequency ◽  
Strain Energy ◽  
Natural Frequencies ◽  
Planetary Gear ◽  
Planetary Gears ◽  
System Parameters ◽  
Planet Gear ◽  
Parameter Values ◽  
Grouping Behavior

High natural frequencies of planetary gears tend collect into groups. The modes at these natural frequencies are characterized by motion of the planet gears with strain energy in the tooth meshes and planet bearings. Each group has one rotational, one translational, and one planet mode. The groups change in natural frequency together when system parameters are varied. The grouping behavior is disrupted with significant differences in planet-to-planet gear parameter values.

Magnetic planetary gear drive

2009 ◽  
Vol 223 (9) ◽  
pp. 2167-2181 ◽  
Author(s):  
L Xu ◽  
X Zhu
Keyword(s):  
Planetary Gear ◽  
Speed Ratio ◽  
Magnetic Torque ◽  
Planetary Gears ◽  
Gear Teeth ◽  
Gear Drive ◽  
Tooth Width ◽  
Pair Number ◽  
Magnetic Gear ◽  
Crown Gear

In this study, a magnetic planetary gear drive is proposed and its operating principle is introduced. The equations of the geometrics and kinematics for the drive are given. The equations of the magnetic induction intensity for the magnetic gear teeth are deduced. The equations of the torques between the planetary gears and sun gear or crown gear are developed. The available parameters of the magnetic planetary drive are presented and the magnetic flux density distributions of the magnetic gear teeth are investigated. The torques between the planetary gears and sun gear or crown gear are analysed. When the relative rotating angle between the gears is increased, the magnetic torque grows, gets to a maximum value, and then drops. The maximum torque represents extreme load-carrying ability of the drive system. The pole pair number, the tooth thickness and the tooth width of the magnetic gears, and the speed ratio of the drive have obvious influence on the output torques. To obtain a large magnetic torque, a large tooth width of the gear, a proper pole pair number, a proper radial thickness of the tooth, a large planetary gear number, and a large speed ratio should be chosen.

scholarly journals ANALYTICAL MODELING OF PLANETARY GEAR AND SENSITIVITY OF NATURAL FREQUENCIES

2013 ◽  
pp. 35-40
Author(s):  
MAJID MEHRABI ◽  
DR. V.P. SINGH
Keyword(s):  
Natural Frequency ◽  
Degrees Of Freedom ◽  
Analytical Modeling ◽  
Natural Frequencies ◽  
Vibration Mode ◽  
Planetary Gear ◽  
Vibration Modes ◽  
Planetary Gears ◽  
System Parameters ◽  
Inertia Parameters

This work develops an analytical model of planetary gears and uses it to investigate their natural frequencies and vibration modes. The model admits three planar degrees of freedom for each of the sun, ring, carrier and planets. Vibration modes are classified into rotational, translational and planet modes. The natural frequency sensitivities to system parameters are investigated for tuned (cyclically symmetric) planetary gears. Parameters under consideration include support and mesh stiffnesses, component masses, and moments of inertia. Using the well-defined vibration mode properties of tuned planetary gears, the eigen sensitivities are calculated and expressed in simple exact formulae. These formulae connect natural frequency sensitivity with the modal strain or kinetic energy and provide efficient means to determine the sensitivity to all stiffness and inertia parameters by inspection of the modal energy distribution.

scholarly journals An investigation on dynamic characteristics of herringbone planetary gear system with torsional flexibility between the left and right teeth of the sun gear

2020 ◽  
Vol 21 (6) ◽  
pp. 602
Author(s):  
Xiangyang Xu ◽  
Hongwei Ge ◽  
Jijun Deng ◽  
Jibo Wang ◽  
Renxiang Chen
Keyword(s):  
Dynamic Characteristics ◽  
Planetary Gear ◽  
Torsional Stiffness ◽  
Main Peak ◽  
The Sun ◽  
Meshing Stiffness ◽  
Input Side ◽  
Left And Right ◽  
Planetary Gear System ◽  
The Right

Herringbone planetary gear system (HPGS) has high power density and complex structure. The torsional flexibility of the left and right teeth of the sun gear is closely related to the dynamic characteristics of the HPGS. In this research, considering the coordination conditions of both sides torsional stiffness and axial slide of the sun gear, a new dynamic model of the HPGS considering the meshing phase difference between left and right teeth of the sun gear is developed based on the lumped-parameter method, and the influence mechanism of torsional stiffness and axial sliding is studied. Moreover, the dynamic parameters and dynamic characteristics of the HPGS are analyzed in the case of varying torsoinal stiffness and axial slide. The results show that the torsional stiffness of left and right teeth and the axial slide of sun gear have significant impacts on the dynamic parameters and dynamic mesh force response. With the increase of the torsional flexibility (the decrease the torsional stiffness), the sun gear and planet gear meshing stiffness and the maximum tooth surface load are both increased on the left side (input side) and decreased on the right side, but the main peak values and peak frequencies of dynamic response on both sides of the s-p meshing pairs decrease significantly. In addition, when the sun gear slides toward the output side axially, meshing stiffness and dynamic mesh force response main peak values decreased on the left side (input side) and increased on the right side, but the main resonance peaks frequencies keep the same.

scholarly journals Dynamic modal analysis of double-sided meshing nutation drive with double circular arc spiral bevel gears

2020 ◽  
Vol 11 (1) ◽  
pp. 115-123
Author(s):  
Zheng Lin ◽  
Ligang Yao ◽  
Zhiyu Xie
Keyword(s):  
Modal Analysis ◽  
Natural Frequencies ◽  
Transmission Error ◽  
Drive System ◽  
Nonlinear Dynamic Model ◽  
Circular Arc ◽  
Spiral Bevel Gears ◽  
Bevel Gears ◽  
Meshing Stiffness ◽  
Spiral Bevel

Abstract. In order to reduce the vibration of the double-sided meshing nutation drive with double circular arc spiral bevel gears, the dynamic modal of the nutation system is analyzed. The bending-torsional-axial coupling nonlinear dynamic model of the double-sided meshing nutation drive system with time-varying meshing stiffness, meshing damping, transmission error and tooth backlash is established, and the equation of motion of the system is derived. The natural frequencies and corresponding modal modes of the nutation system are calculated, and the effects of the average meshing stiffness of gears and the bearing support stiffness of nutation gears on the modal of the system are analyzed. The modal analysis of double circular arc spiral bevel gears is carried out, and the ten order natural frequencies and their corresponding modes are obtained. The results show that the nutation drive system and the double circular arc spiral bevel gears do not resonate during transmission.

scholarly journals Numerical Analysis on Chaotic Vibration of Drive System for a Movable Tooth Piezoelectric Motor

2017 ◽  
Vol 2017 ◽  
pp. 1-17 ◽  
Author(s):  
Chong Li ◽  
Jichun Xing ◽  
Jiwen Fang ◽  
Zhong Zhao
Keyword(s):  
Numerical Analysis ◽  
Drive System ◽  
Dynamic Equations ◽  
Piezoelectric Motor ◽  
Mesh Stiffness ◽  
System Parameters ◽  
Chaotic Vibrations ◽  
Chaotic Vibration ◽  
Nonlinear Dynamic Equations ◽  
Wave Generator

The nonlinear dynamic equations of the drive system for movable tooth piezoelectric motor are established. Using these equations, the chaotic vibrations of the system are investigated. The results show that chaotic vibrations occur in the movable tooth drive system under some parameters. The average mesh stiffness, theoretical radius, and wave generator offset significantly influence the nonlinear chaotic vibrations of the drive system of the movable tooth piezoelectric motor. The ranges for the system parameters that lead to a motor with bad dynamics are shown. The results can be used to predict the dynamic load and optimize power density of the proposed piezoelectric motor.

scholarly journals VIBRATION ANALYSIS OF PLANETARY GEAR SYSTEM

2013 ◽  
pp. 30-34
Author(s):  
MAJID MEHRABI ◽  
DRV.P. SINGH
Keyword(s):  
Vibration Analysis ◽  
Natural Frequencies ◽  
Linear Time ◽  
Planetary Gear ◽  
Vibration Modes ◽  
System Parameters ◽  
Linear Time Invariant ◽  
Inertia Parameters ◽  
Planetary Gear System ◽  
Time Invariant

In this work a dynamic model of a planetary gear transmission is developed to study the sensitivity of the natural frequencies and vibration modes to system parameters in perturbed situation. Parameters under consideration include component masses ,moment of inertia , mesh and support stiff nesses .The model admits three planar degree of freedom for planets ,sun, ring, and carrier. Vibration modes are classified into translational, rotational and planet modes .Well-defined modal properties of tuned (cyclically symmetric) planetary gears for linear ,time-invariant case are used to calculate eigensensitivities and express them in simple formulae .These formulae provide efficient mean to determine the sensitivity to stiffness ,mass and inertia parameters in perturbed situation.

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