Calculation of time dependent mesh stiffness of helical planetary gear system using analytical approach

2018 ◽  
Vol 32 (8) ◽  
pp. 3537-3545 ◽  
Author(s):  
Mohsen Rezaei ◽  
Mehrdad Poursina ◽  
Shahram Hadian Jazi ◽  
Farhad Haji Aboutalebi
Keyword(s):  
Analytical Approach ◽  
Planetary Gear ◽  
Gear System ◽  
Time Dependent ◽  
Mesh Stiffness ◽  
Planetary Gear System

Dynamic Response Analysis of Wind Turbine Planetary Gear System With Interval Stiffness Parameters

2014 ◽  
Author(s):  
Sha Wei ◽  
Qinkai Han ◽  
Zhipeng Feng ◽  
Yanhua Shen ◽  
Fulei Chu
Keyword(s):  
Wind Turbine ◽  
Planetary Gear ◽  
Transmission Error ◽  
Gear System ◽  
Dynamic Responses ◽  
Lumped Parameter Model ◽  
Response Analysis ◽  
Mesh Stiffness ◽  
Gear Trains ◽  
Planetary Gear System

Planetary gear transmission system is one of the primary parts of the wind turbine drive train. Due to the assembly state, lubrication conditions and wear, the mesh stiffness of the planetary gear system is an uncertain parameter. In this paper, taking the uncertainty of mesh stiffness into account, the dynamic responses of a wind turbine gear system subjected to wind loads and transmission error excitations are studied. Firstly, a lumped-parameter model is extended to include both the planetary and parallel gears. Then the fluctuation ranges of dynamic mesh forces are predicted quantitatively and intuitively based on the combined Chebyshev interval inclusion function and numerical integration method. Finally, examples of gear trains with different interval mesh stiffnesses are simulated and the results show that tooth separations are becoming more obvious at the resonant speed by considering the fluctuating mesh stiffness of the second parallel gear stage. The nonlinear tooth separations are degenerated obviously as the fluctuation error of the mesh stiffness of the second parallel gear set is increased.

An analyzing method of coupled modes in multi-stage planetary gear system

2014 ◽  
Vol 15 (11) ◽  
pp. 2357-2366 ◽  
Author(s):  
Wei Sun ◽  
Xin Ding ◽  
Jing Wei ◽  
Xinglong Hu ◽  
Qingguo Wang
Keyword(s):  
Planetary Gear ◽  
Gear System ◽  
Coupled Modes ◽  
Multi Stage ◽  
Planetary Gear System

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.

Effect of the bearing clearance on vibrations of a double-row planetary gear system

2019 ◽  
Vol 234 (2) ◽  
pp. 347-357
Author(s):  
Jing Liu ◽  
Shizhao Ding ◽  
Linfeng Wang ◽  
Hongwu Li ◽  
Jin Xu
Keyword(s):  
Contact Stiffness ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Gear System ◽  
Double Row ◽  
External Torque ◽  
Bearing Clearance ◽  
Gear Systems ◽  
Planetary Gear System ◽  
Stiffness And Damping

The bearing clearance, external torque, and input speed can greatly affect vibrations of the planetary gear system. The double-row planetary gear systems are commonly used in the gearbox of special vehicles, which are the key parts to obtain a larger gear ratio. Although many works have been presented to study those factors on vibrations of the single-row planetary gear system, a few works were focused on vibrations of the double-row planetary gear system with the bearing clearance. To overcome this problem, a multi-body dynamic model of a double-row planetary gear system with six planet bearings and one supported bearing of the sun gear is presented. This model is the main part of a gear box transmission system. The new model is developed for studying the effect of the bearing clearance on the planetary system. The meshing stiffness and damping between the gears are obtained by current methods in the listed references, as well as the contact stiffness and damping in bearings. The liner stiffness and damping model is used. The effects of the bearing clearance, external torque, and input speed on vibrations of the system are analyzed. The results show that vibrations of the ring gear and sun gear decrease with the increment of the external torque and increase with the increment of the input speed. Moreover, a reasonable bearing clearance can be helpful for reducing system vibrations for some mating external torque and input speed conditions. The results can provide some guidance to find new method to reduce vibrations and increase the service life of planetary gear systems.

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.

Design and Test of Differential Planetary Gear System for Open Rotor Power Gearbox

2013 ◽  
Author(s):  
Hideyuki Imai ◽  
Tatsuhiko Goi ◽  
Kenichi Kijima ◽  
Tooru Nishida ◽  
Hidenori Arisawa ◽  
...  
Keyword(s):  
Performance Test ◽  
High Efficiency ◽  
High Reliability ◽  
Gear Tooth ◽  
Planetary Gear ◽  
Design Concept ◽  
Gear System ◽  
Open Rotor ◽  
Planetary Gear System ◽  
Validation Tests

The open rotor engine is a next generation aero-engine that satisfies the demand for high fuel efficiency and low CO2 emission. A differential planetary gear system is incorporated in the open rotor engine to connect the turbine output shaft and fan rotors in order to counter-rotate the fan rotors as well as allow the turbine and fan rotors to operate at more efficient speeds. The open rotor gear system is required to have not only 20,000 hp high power transmission, but also an increasingly high efficiency, high reliability and light weight. To achieve these requirements, the following design works were conducted; (1) a low misalignment and lightweight carrier, (2) a flexible structure to absorb the displacement caused by the flight load, (3) an optimum gear tooth modification and (4) reduction of oil churning and windage losses. Also, extensive analyses and simulations such as lube oil flow CFD, FEA and tooth contact analysis were conducted. A full scale prototype gear system was manufactured and validation tests were conducted using a newly constructed test rig to validate the design concept. A slow roll test, rated performance test and efficiency test were conducted. And the design concept was found to be valid. This paper describes details of the prototype design and the results of the validation tests.

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