Dynamic Analysis of Helical Planetary Gear Train

2013 ◽  
Vol 404 ◽  
pp. 312-317 ◽  
Author(s):  
Xian Zeng Liu ◽  
Jun Zhang
Keyword(s):  
Steady State ◽  
Free Vibration ◽  
Dynamic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Design Parameters ◽  
Planetary Gear Train ◽  
State Dynamic ◽  
The Impact

A dynamic model for helical planetary gear train (HPGT) is proposed. Based on the model, the free vibration characteristics, steady-state dynamic responses and effects of design parameters on system dynamics are investigated through numerical simulations. The free vibration of the HGPT is classified into 3 categories. The classified vibration modes are demonstrated as axial translational and torsional mode (AT mode), radial translational and rotational mode (RR mode) and planet mode (P mode) followed by the characteristics of each category. The simulation results agree well with those of previous discrete model when neglecting the component flexibilities, which validates the correctness of the present dynamic model. The steady-state dynamic responses indicate that the dynamic meshing forces fluctuate about the average static values and the time-varying meshing stiffness is one of the major excitations of the system. The parametric sensitivity analysis shows that the impact of the central component bearing stiffness on the dynamic characteristic of the HPGT system is significant.

Dynamics of the Gear Train Set in Wind Turbine

2011 ◽  
Vol 697-698 ◽  
pp. 701-705
Author(s):  
D.D. Ji ◽  
Y.M. Song ◽  
J. Zhang
Keyword(s):  
Wind Turbine ◽  
Dynamic Model ◽  
Harmonic Balance Method ◽  
Planetary Gear ◽  
Gear Train ◽  
Dynamic Responses ◽  
Multi Stage ◽  
Lumped Parameter ◽  
Cartesian Coordinate ◽  
The Impact

A lumped-parameter dynamic model for gear train set in wind turbine is proposed to investigate the dynamics of the speed-increasing gear box. The proposed model is developed in a universal Cartesian coordinate, which includes transversal and torsional deflections of each component, time-varying mesh stiffness, gear profile errors and external excitations. By solving the dynamic model, a modal analysis is performed. The results indicate that the modal properties of the multi-stage gear train in wind turbine are similar to those of a single-stage planetary gear set. A harmonic balance method (HBM) is used to obtain the dynamic responses of the gearing system. The responses give insight into the impact of excitations on the vibrations.

Vibration Characteristics of Friction Plate of a 6-Speed Planetary Gear Train Base on Multi-Body Dynamic Model

2017 ◽  
Author(s):  
Tinghui Su ◽  
Zheng Cao ◽  
Yimin Shao ◽  
Liming Wang ◽  
Hongwu Li ◽  
...  
Keyword(s):  
Dynamic Model ◽  
Impact Damage ◽  
Planetary Gear ◽  
Vibration Characteristics ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Operation Conditions ◽  
Friction Plate ◽  
Multi Body ◽  
The Impact

As braking components, friction plates are key components in automobile transmissions. Due to tough working conditions, i.e. high speed, high friction, fracture and plastic deformation are easily observed in friction plates. However, most of previous studies mainly focused on the chemical analysis of the fracture friction plate, the researches on impact damage have rarely published in the listed literature. In order to investigate the impact damage for friction plate, a dynamic model for a friction plate of a 6-speed planetary gear train is established based on multi-body theory. The dynamic model of planetary gear transmission mechanism is constructed. The rotating speed of the inner hub is obtained. Furthermore, the contact force between the friction plate and the inner hub is calculated. The relationship between the vibration characteristics of the friction plate and operation conditions are studied.

Dynamic Characteristic Research on Thin Rim Structure for Herringbone Planetary Gear Train

2010 ◽  
Vol 44-47 ◽  
pp. 1514-1518
Author(s):  
Shang Jun Ma ◽  
Geng Liu ◽  
Zhong Hong Bu
Keyword(s):  
Steady State ◽  
Planetary Gear ◽  
Gear Train ◽  
Thin Wall ◽  
Steady State Response ◽  
Planetary Gear Train ◽  
State Response ◽  
Mode Superposition Method ◽  
Internal Gear ◽  
Herringbone Planetary Gear Train

A torsional and translational vibration dynamics model for serial herringbone planetary gear train, which considers the effects of the time-varying errors and meshing stiffness as well as elastic coupling between two stage trains at the same time, was established by using lumped mass method. Time domain dynamic load excitation which derived from dynamics equation is taken as the input of steady-state response solution. The steady-state response of gear structure was solved with mode superposition method combined with external judgment program. The effects of rim thickness for thin wall herringbone planetary gear and single-stage internal gear were also analyzed. Through the comparison, the displacement and stress results of key locations on structure have reached the satisfying and disirable values when the rim thickness of planetary gear is greater than 4.0 mn and rim thickness of internal gear greater than 6.5 mn.

STEADY STATE AND DYNAMIC MODELING OF AN INDIRECT DISTRICT HEATING SYSTEM

2010 ◽  
Vol 18 (01) ◽  
pp. 61-75 ◽  
Author(s):  
L. LI ◽  
M. ZAHEERUDDIN ◽  
SUNG-HWAN CHO ◽  
SANG-HOON JUNG
Keyword(s):  
Steady State ◽  
Dynamic Model ◽  
District Heating ◽  
Heating System ◽  
Dynamic Responses ◽  
District Heating System ◽  
Steady State Model ◽  
Heated Floor ◽  
The Impact ◽  
Important System

An indirect district heating system (IDHS) with heated floor area of 851 031 m2 and ten heat exchange stations was modeled in this study. An aggregated steady state model for the system was developed to study the impact of important system parameters. A dynamic model of the IDHS was developed based on energy balance principles. The dynamic model consists of sub-system models such as boiler, pipe network, heat exchanger, terminal heater and zone models. Simulation results of the dynamic responses show that the overall efficiency of the IDHS system is 78.7%, and the two highest heat loss components are the boiler heat losses and the secondary water makeup loss.

Free vibration characteristics of compound planetary gear train sets

2008 ◽  
Vol 222 (8) ◽  
pp. 1389-1401 ◽  
Author(s):  
S Dhouib ◽  
R Hbaieb ◽  
F Chaari ◽  
M S Abbes ◽  
T Fakhfakh ◽  
...  
Keyword(s):  
Free Vibration ◽  
Rotation Speed ◽  
Angular Position ◽  
Planetary Gear ◽  
Vibration Characteristics ◽  
Operating Conditions ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Lagrange Formulation ◽  
Natural Modes

In this study, a plane model of a compound planetary gear train (CPGT) is proposed in order to study its free vibration characteristics. Two translations and one rotation are considered for each element (sun, carrier, ring-1, ring-2, and planets) of the CPGT. The contact between the teeth in mesh is modelled by linear springs with stiffness called gearmesh stiffness. The phasing between these stiffness is taken into account. Using Lagrange formulation, the equation of motion is derived. Starting from the eigenvalue problem of the system, the influence of the planets’ number and position, and the effect of the gyroscopic phenomena on the free vibration of the CPGT are studied. The natural modes are classified into three groups: translational (the carrier, ring 1, and sun have pure modal translational deflection with no rotation), rotational (the carrier, ring 1, and sun have pure modal rotational deflection with no translation), and planets’ modes (only the planets have a modal deflection). It was found that the change of the planets’ angular position does not affect this classification. On the other hand, the study of the influence of the carrier rotation speed show that the gyroscopic effect separates the repeated translational modes into distinct ones. The obtained results are much important in the design process in order to avoid critical operating conditions which lead to undesirable vibrations.

Multi-Objective Optimization for the Efficiency and Weight of Helicopter Transmission Planetary Gear Train

2014 ◽  
Vol 635-637 ◽  
pp. 177-180
Author(s):  
Kang Huang ◽  
Xiao Hui Zhu ◽  
Xiang Chen ◽  
Gong Chuan Xia
Keyword(s):  
Planetary Gear ◽  
Optimization Method ◽  
Gear Train ◽  
Transmission Ratio ◽  
Design Parameters ◽  
Multi Objective Optimization ◽  
Planetary Gear Train ◽  
Multi Objective ◽  
Critical Design ◽  
Helicopter Transmission

A multi-objective optimization method for the optimization of the efficiency and weight of helicopter transmission planetary gear train was established. Taking the transmission ratio, efficiency weight, and reliability as critical design parameters, taking the conditions of the planetary gear train itself and the strength check constraint for the gear train as constraint functions, making the weight and efficiency of the planetary gear train asoptimization targets and using the Matlab function fgoalattain, a multi-objective optimization has been made. Comparison between the initial and the optimized results showed the success of the optimized planetary gear train in reducing the weight and increasing the efficiency.

A multi-body dynamic study of vibration of a planetary gear train with the planetary bearing fault

2019 ◽  
Vol 233 (3) ◽  
pp. 677-695 ◽  
Author(s):  
Jing Liu ◽  
Linfeng Wang ◽  
Jinlei Ma ◽  
Wennian Yu ◽  
Yimin Shao
Keyword(s):  
Dynamic Model ◽  
Dynamic Modelling ◽  
Planetary Gear ◽  
Elastic Support ◽  
Gear Train ◽  
Radial Clearance ◽  
Ring Gear ◽  
Planetary Gear Train ◽  
Multi Body ◽  
Body Dynamic

Local faults including pits and spalls in any planet bearing can greatly affect the vibration of the planetary gear train, as well as the elastic support of the ring gear. However, the dynamic modelling methods in previous work can only formulate the local fault and the elastic support of the ring gear independently. To address this issue, a multi-body dynamic model for a planetary gear train with a local fault in the planet bearing and an elastic ring gear foundation are introduced to analyze the effect of local fault on the vibration. The local fault in the planet bearing is modelled as a rectangular one. Both the planet bearings including the radial clearance and ring gear with an elastic foundation are considered in the multi-body dynamic model. The contact stiffnesses and damping coefficients of gears and bearings are calculated by the methods reported in the literature. A Coulomb friction model is adopted to model the frictions between mating components of the system. In order to validate the proposed multi-body dynamic model, its simulation results are directly compared with those from theoretical methods as well as the experimental methods reported in the literature. Moreover, parameter studies are conducted to discuss the effects of local faults in the planet-bearing races, the sun gear speed, and the carrier moment on the vibration of the planetary gear train. The analyzing results of this study can provide some guidance for detection approaches of local faults in the planet bearings of planetary gear trains through vibration analysis.

scholarly journals Impacts of Backlash on Nonlinear Dynamic Characteristic of Encased Differential Planetary Gear Train

2019 ◽  
Vol 2019 ◽  
pp. 1-15 ◽  
Author(s):  
Zengbao Zhu ◽  
Longchao Cheng ◽  
Rui Xu ◽  
Rupeng Zhu
Keyword(s):  
Dynamic Equation ◽  
Nonlinear Dynamic ◽  
Planetary Gear ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Gear Teeth ◽  
Nonlinear Dynamic Equation ◽  
Motion State ◽  
Nonlinear Dynamic Characteristic ◽  
The Impact

A multifreedom tensional nonlinear dynamic equation of encased differential planetary gear train with multibacklash and time-varying mesh stiffness was developed in the present research. The nonlinear dynamic response was obtained by solving the formulated nonlinear dynamic equation, and the impacts of backlash on dynamic characteristics of the gear train were then analyzed by combining time process diagram, phase diagram, and Poincaré section. The results revealed that bilateral shock in meshing teeth was caused due to smaller backlash, thus causing dramatic changes in meshing force; hence, the gears were found to be in a chaotic state. Further, during stable motion state, no contact between intermeshing teeth with bigger backlash was noticed; thus, they were in a stable quasiperiodic motion state in the absence of teeth exciting force. Therefore, in order to avoid a bilateral shock in gears as well as to maintain gear teeth lubrication, a slightly bigger backlash is required. The backlash change in any transmission stage caused significant impacts on gear force and the motion state of its own stage; however, the impact on gear force of another stage was quite small, whereas the impact on the motion state of another stage was quite large.

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