scholarly journals Numerical calculation and experimental measurement for gear mesh force of planetary gear transmissions

2022 ◽  
Vol 162 ◽  
pp. 108085
Author(s):  
He Dai ◽  
Feng Chen ◽  
Chao Xun ◽  
Xinhua Long
Keyword(s):  
Numerical Calculation ◽  
Experimental Measurement ◽  
Planetary Gear ◽  
Gear Mesh

Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

2015 ◽  
Author(s):  
Fengxia Lu ◽  
Rupeng Zhu ◽  
Haofei Wang ◽  
Heyun Bao ◽  
Miaomiao Li
Keyword(s):  
Degrees Of Freedom ◽  
Sliding Friction ◽  
Planetary Gear ◽  
Gear Train ◽  
Variable Step Size ◽  
Step Size ◽  
Planetary Gear Train ◽  
Gear Mesh ◽  
Meshing Stiffness ◽  
Nonlinear Dynamics Model

A new nonlinear dynamics model of the double helical planetary gear train with 44 degrees of freedom is developed, and the coupling effects of the sliding friction, time-varying meshing stiffness, gear backlashes, axial stagger as well as gear mesh errors, are taken into consideration. The solution of the differential governing equation of motion is solved by variable step-size Runge-Kutta numerical integration method. The influence of tooth friction on the periodic vibration and nonlinear vibration are investigated. The results show that tooth friction makes the system motion become stable by the effects of the periodic attractor under the specific meshing frequency and leads to the frequency delay for the bifurcation behavior and jump phenomenon in the system.

An Analytical and Numerical Investigation of Modulation Sidebands of a Planetary Gear Under Fluctuated External Torque

2018 ◽  
Author(s):  
Yunbo Yuan ◽  
Wei Liu ◽  
Yahui Chen ◽  
Donghua Wang
Keyword(s):  
Planetary Gear ◽  
Transmission Error ◽  
Operating Conditions ◽  
Radial Acceleration ◽  
External Torque ◽  
Gear Mesh ◽  
Planetary Gear Sets ◽  
Static Transmission Error ◽  
Frequency Modulations ◽  
Mesh Phasing

Certain operating conditions such as fluctuation of the external torque to planetary gear sets can cause additional sidebands. In this paper, a mathematical model is proposed to investigate the modulation mechanisms due to a fluctuated external torque (FET), and the combined influence of such an external torque and manufacturing errors (ME) on modulation sidebands. Gear mesh interface excitations, namely gear static transmission error excitations and time-varying gear mesh stiffness, are defined in Fourier series forms. Amplitude and frequency modulations are demonstrated separately. The predicted dynamic gear mesh force spectra and radial acceleration spectra at a fixed position on ring gear are both shown to exhibit well-defined modulation sidebands. Comparing with sidebands caused by ME, more complex sidebands appear when taking both FET and ME into account. An obvious intermodulation is found around the fundamental gear mesh frequency between the FET and ME in the form of frequency modulations, however, no intermodulation in the form of amplitude modulations. Additionally, the results indicate that some of the sidebands are cancelled out in radial acceleration spectra mainly due to the effect of planet mesh phasing, especially when only amplitude modulations are present.

A Three-Dimensional Load Sharing Model of Planetary Gear Sets Having Manufacturing Errors

2015 ◽  
Author(s):  
Nicholas D. Leque ◽  
Ahmet Kahraman
Keyword(s):  
Three Dimensional ◽  
Planetary Gear ◽  
Load Sharing ◽  
Distribution Model ◽  
Gear Mesh ◽  
Position Errors ◽  
Proposed Model ◽  
Manufacturing Errors ◽  
Manufacturing Tolerancing ◽  
Planetary Gear Sets

Planet-to-planet load sharing is a major design and manufacturing tolerancing issue in planetary gear sets. Planetary gear sets are advantageous over their countershaft alternatives in many aspects, provided that each planet branch carries a reasonable, preferably equal, share of the torque transmitted. In practice, the load shared among the planets is typically not equal due to the presence of various manufacturing errors. This study aims at enhancing the models for planet load sharing through a three-dimensional formulation of N-planet helical planetary gear sets. Apart from previous models, the proposed model employs a gear mesh load distribution model to capture load and time dependency of the gear meshes iteratively. It includes all three types of manufacturing errors, namely constant errors such as planet pinhole position errors and pinhole diameter errors, constant but assembly dependent errors such as nominal planet tooth thickness errors, planet bore diameter errors, and rotation and assembly dependent errors such as gear eccentricities and run-outs. At the end, the model is used to show combined influence of these errors on planet load sharing to aid designers on how to account for manufacturing tolerances in the design of the gears of a planetary gear set.

Torsional Vibrations and Dynamic Loads in a Basic Planetary Gear System

1986 ◽  
Vol 108 (3) ◽  
pp. 348-353 ◽  
Author(s):  
R. August ◽  
R. Kasuba
Keyword(s):  
Dynamic Model ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear System ◽  
Dynamic Loads ◽  
Ring Gear ◽  
Gear Mesh ◽  
Input And Output ◽  
Planetary Gear System ◽  
Three Degrees Of Freedom

An interative method has been developed for analyzing dynamic loads in a light weight basic planetary gear system. The effects of fixed, semi-floating, and fully-floating sun gear conditions have been emphasized. The load dependent variable gear mesh stiffnesses were incorporated into a practical torsional dynamic model of a planetary gear system. The dynamic model consists of input and output units, shafts, and a planetary train. In this model, the sun gear has three degrees of freedom; two transverse and one rotational. The planets, ring gear, and the input and output units have one degree of freedom, (rotation) thus giving a total of nine degrees of freedoms for the basic system. The ring gear has a continuous radial support. The results indicate that the fixed sun gear arrangement with accurate or errorless gearing offers in general better performance than the floating sun gear system.

Effect of Rim Thickness on Tooth Root Stress and Mesh Stiffness of Internal Gears

2014 ◽  
Author(s):  
F. Karpat ◽  
B. Engin ◽  
O. Dogan ◽  
C. Yuce ◽  
T. G. Yilmaz
Keyword(s):  
Weight Ratio ◽  
Planetary Gear ◽  
Mesh Stiffness ◽  
Gear Mesh ◽  
Aerospace Applications ◽  
Bending Stresses ◽  
Gear Mechanism ◽  
Internal Gear ◽  
Gear Mesh Stiffness ◽  
Root Stress

In recent years, internal gears are used commonly in a number of automotive and aerospace applications especially in planetary gear drives. Planetary gears have many advantages such as compactness, large torque-to-weight ratio, large transmission ratios, reduced noise and vibrations. Although internal gears have many advantages, there are not enough studies on it. Designing an internal gear mechanism includes two important parameters. The gear mesh stiffness which is the main excitation source of the system. In this paper, 2D gear models are developed in order to compute gear mesh stiffness for various rim thicknesses and different rim shapes of the internal gear design. Effects of root stress with varying rim thickness and some tooth parameters are investigated by using 2D gear models. The stress calculated according to ISO 6336 and the stresses calculated against FEM are compared. These results are well-matched. It is observed that when the rim thicknesses are increased, both the maximum bending stresses and gear mesh stiffness are decreased considerably.

Study on Helical Tooth Profile Modification of Planetary Gear Transmission on the Basis of Gear Transmission Error

2011 ◽  
Vol 86 ◽  
pp. 47-50
Author(s):  
Yu Tang ◽  
Shan Chang ◽  
Zhi Qiang Wang ◽  
Kun Zhang
Keyword(s):  
Planetary Gear ◽  
Transmission Error ◽  
Tooth Profile ◽  
Gear Transmission ◽  
Mesh Stiffness ◽  
Profile Modification ◽  
Gear Mesh ◽  
Tooth Profile Modification ◽  
Planetary Transmission ◽  
Gear Mesh Stiffness

In order to minimize the fluctuation of gear transmission error (GTE) about the planetary gear transmission. A method was developed to deciding tooth profile modification curves of planetary transmission. According to the condition of the invariable design load, computing the dynamic characteristics of the planetary transmission system under modified and un-modified gear. At the same time, the compare is carried through of the dynamic characteristics for modified and un-modified gear. The results of the dynamic calculation indicate that the profile modification method can make the amplitudes of gear mesh stiffness change calmness and reduce the amplitudes of gear mesh stiffness by this method in paper. At last, the conclusion can be obtained that the tooth profile modification can reduce the vibration and noise of the planetary transmission system.

scholarly journals Stress Assessment of Gear Teeth in Epicyclic Gear Train for Radial Sedimentation Tank

2020 ◽  
Vol 14 (3) ◽  
pp. 121-127
Author(s):  
Grzegorz Budzik ◽  
Tadeusz Markowski ◽  
Michał Batsch ◽  
Jadwiga Pisula ◽  
Jacek Pacana ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Load Factor ◽  
The Finite Element Method ◽  
Gear Teeth ◽  
Gear Mesh ◽  
Sedimentation Tank ◽  
Epicyclic Gear ◽  
Comparison Of The Results ◽  
Root Stress

Abstract The paper presents the strength evaluation of planetary gear teeth designed for a radial sedimentation tank drive. A novel type of gear drive, composed of a closed epicyclic gear train and an open gear train with internal cycloidal gear mesh is proposed. Contact stress and root stress in the planetary gear train were determined by the finite element method and according to ISO 6336. The influence of the mesh load factor at planet gears on stress values was also established. A comparison of the results followed. It was observed that the mesh load factor on satellites depends mainly on the way the satellites and central wheels are mounted, the positioning accuracy in the carrier and the accuracy of teeth. Subsequently, a material was selected for the particular design of planetary gear and the assumed load. The analysis of the obtained results allowed assuming that in case of gears in class 7 and the rigid mounting of satellites and central wheels, gears should be made of steel for carburizing and hardening. In case of flexible satellites or flexible couplings in the central wheels and gears in class 4, gears can be made of nitriding steel.

Condition Monitoring of Motor-Gear System Dynamics With Rotor and Gear Faults

2020 ◽  
Vol 15 (11) ◽  
Author(s):  
Wenyu Bai ◽  
Guanjun Bao ◽  
Datong Qin ◽  
Yawen Wang ◽  
Teik C. Lim
Keyword(s):  
Condition Monitoring ◽  
Planetary Gear ◽  
Response Spectra ◽  
Rotational Frequency ◽  
Gear System ◽  
Electromechanical System ◽  
Gear Mesh ◽  
Dynamic Eccentricity ◽  
Mechanical Faults ◽  
Slip Frequency

Abstract An electromechanical system consisting of an electric motor and planetary gear set is modeled and analyzed in this paper. The model integrates various internal excitations including time-varying gear mesh stiffness, nonlinear spatial effect and, saturation effect, and component flaws. The simulation results predict the effects of rotor and gear faults including broken rotor bar, rotor static and dynamic eccentricity, and tooth root crack of the gear on the electromechanical system behavior. It is verified as the results obtained are in accordance with the features derived within previous researches. Furthermore, new sidebands merged on the dynamic response spectra such as slip frequency harmonics, rotor rotational frequency harmonics, and fault-related rotational frequency harmonics can be applied to detect electrical and mechanical faults in the motor-gear system. This paper lays the foundation for the comprehensive further study of working condition monitoring for the motor-gear system.

A Load Distribution Model for Double-Planet Planetary Gear Sets

2019 ◽  
Author(s):  
Yong Hu ◽  
David Talbot ◽  
Ahmet Kahraman
Keyword(s):  
Load Distribution ◽  
Gear Tooth ◽  
Planetary Gear ◽  
System Level ◽  
Distribution Model ◽  
Ring Gear ◽  
Gear Mesh ◽  
Manufacturing Errors ◽  
Planetary Gear Sets ◽  
Bearing Stiffness

Abstract In this paper, a load distribution model for a double-planet planetary gear set is developed by modifying an existing single-planet planetary gear set model [1] to account for an additional planet to planet gear mesh and their impact on phasing relationship among different sun-planet, planet-planet and planet-ring gear meshes. Similar to the single-planet planetary gear set model, the double-planet planetary gear set model accounts for effects of various component and system level variations such as supporting conditions, gear tooth modifications, manufacturing errors and kinematic configurations. The double-planet planetary gear load distribution model is derived for both rigid and flexible ring gear rim, while only parametric studies for a rigid ring gear rim is presented in this paper to demonstrate load distribution characteristics of double-planet planetary gear sets with different planet bearing stiffness and combination of various types of manufacturing errors, including pin hole position error and runout errors.

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