Nonlinear dynamic model and governing equations of low speed and high load planetary gear train with respect to friction

2011 ◽  
Author(s):  
Chen Shiqi ◽  
Zhao Jiyun ◽  
Li Bingwen ◽  
Xu Zhan ◽  
Feng Yanqiu
Keyword(s):  
Dynamic Model ◽  
Nonlinear Dynamic ◽  
Planetary Gear ◽  
High Load ◽  
Gear Train ◽  
Governing Equations ◽  
Nonlinear Dynamic Model ◽  
Planetary Gear Train ◽  
Low Speed

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.

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.

Research on Tooth Profile Modification of the Herringbone Planetary Gear Train

2015 ◽  
Author(s):  
Heyun Bao ◽  
Huan Liu ◽  
Rupeng Zhu ◽  
Fengxia Lu ◽  
Miaomiao Li
Keyword(s):  
Rotational Speed ◽  
Planetary Gear ◽  
Transmission Error ◽  
Gear Train ◽  
Maximum Magnitude ◽  
Nonlinear Dynamic Model ◽  
Planetary Gear Train ◽  
Straight Line ◽  
The Impact ◽  
Herringbone Planetary Gear Train

A bending-torsional coupled nonlinear dynamic model which contains the modification parameters of herringbone planetary gear train is presented. A formula of modification incentive is analyzed and deduced. The impact of the straight line and parabolic modification parameters on the amplitude of system transmission error is researched. The optimum modification parameters are acquired according to the minimum amplitude of system transmission error. Different amplitudes of the system transmission error, before and after modification, are compared at different rotational speed. The results indicate that the straight line modification parameters on the amplitude of system transmission error are more sensitive. Modification parameters on the amplitude of system transmission error are researched. When the length of the modification is specified, the amplitude of system transmission error is reduced sharply at first, then increased rapidly with the maximum magnitude of the modification increasing; When the maximum magnitude of the modification is specified, the amplitude of system transmission error is increased weakly at first, then decreased sharply, and increased rapidly in the end, with the length of the modification increasing. The modification parameters could form a crescent-shaped zone which can reduce the system transmission error amplitude significantly. The amplitudes of the system transmission error with modification are all reduced at different rotational speed, especially when there is a sympathetic vibration.

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.

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