Geometric design and kinematics analysis of coplanar double internal meshing non-circular planetary gear train

A new type of non-circular planetary gear train is proposed, in which the planetary gear is internally meshed with the sun gear and the ring gear at the same time. The structural form and transmission principle are analyzed, and the design method of non-circular gear pitch curves and related parameters of the gear train are discussed. The input–output relationship under various working conditions of the gear train is deduced. The precise tooth profile of the non-circular gears is obtained by the Boolean operation of MATLAB, then the virtual prototype model of the planetary gear train is established, and the kinematics simulation is carried out in the ADAMS software. The simulation results verify the correctness of the transmission principle and the theoretical analysis of the motion law.

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Design of Vegetable Pot Seedling Pick-up Mechanism with Planetary Gear Train

Chinese Journal of Mechanical Engineering ◽

10.1186/s10033-020-00484-w ◽

2020 ◽

Vol 33 (1) ◽

Author(s):

Zhipeng Tong ◽

Gaohong Yu ◽

Xiong Zhao ◽

Pengfei Liu ◽

Bingliang Ye

Keyword(s):

Design Method ◽

Planetary Gear ◽

Gear Train ◽

Dimensional Synthesis ◽

Planetary Gear Train ◽

Key Points ◽

Physical Prototype ◽

Noncircular Gears ◽

Pitch Curve ◽

Parameter Values

Abstract It has been challenging to design seedling pick-up mechanism based on given key points and trajectories, because it involves dimensional synthesis and rod length optimization. In this paper, the dimensional synthesis of seedling pick-up mechanism with planetary gear train was studied based on the data of given key points and the trajectory of the endpoint of seedling pick-up mechanism. Given the positions and orientations requirements of the five key points, the study first conducted a dimensional synthesis of the linkage size and center of rotation. The next steps were to select a reasonable solution and optimize the data values based on the ideal seedling trajectory. The link motion was driven by the planetary gear train of the two-stage gear. Four pitch curves of noncircular gears were obtained by calculating and distributing the transmission ratio according to the data. For the pitch curve with two convex points, the tooth profile design method of incomplete noncircular gear was applied. The seedling pick-up mechanism was tested by a virtual prototype and a physical prototype designed with the obtained parameter values. The results were consistent with the theoretical design requirements, confirming that the mechanism meets the expected requirements for picking seedlings up. This paper presents a new design method of vegetable pot seedling pick-up mechanism for an automatic vegetable transplanter.

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Research on design method of non-circular planetary gear train transplanting mechanism based on precise poses and trajectory optimization

Advances in Mechanical Engineering ◽

10.1177/1687814018814368 ◽

2018 ◽

Vol 10 (12) ◽

pp. 168781401881436

Author(s):

Xiong Zhao ◽

Mengyan Chu ◽

Xingxiao Ma ◽

Li Dai ◽

Bingliang Ye ◽

...

Keyword(s):

Trajectory Optimization ◽

Design Method ◽

Planetary Gear ◽

Trajectory Control ◽

Gear Train ◽

Control Points ◽

Transmission Performance ◽

Planetary Gear Train ◽

Precise Position ◽

Solution Domain

Among all kinds of transplanting mechanisms which are the important parts of transplanters, the planetary gear train transplanting mechanism is widely used for its excellent transmission performance, but it is difficult to design the gear pitch curves and structural parameters according to the trajectory and pose requirements of transplanting. The current design method of the non-circular planetary gear train transplanting mechanism cannot ensure the precise position and posture in the crucial points of transplanting trajectory, nor take both the anticipated trajectory and the smoothness of the gear pitch curves into account, it will only get one solution which is available for mechanism design. In order to solve those problems, the non-circular planetary gear train transplanting mechanism is analyzed as a combination of the bar-group and gear train system. According to the transplanting requirements, three points with precise position and posture which called pose points in the trajectory are given to obtain the solution domain of the parameters of bar-group, and then trajectory shape control points are inlet to design the desired shape of the transplanting trajectory and obtain the transmission ratio curve which can be used to get the gear pitch curve. The most suitable parameters of bar-group in solution domain are selected based on the smoothness of the gear pitch curves. This article establishes three-dimensional model of the mechanism and utilizes the ADAMS to carry out a motion simulation; all simulation results are consistent with theoretical design results, which confirm that the design method based on prescribed pose points and trajectory control points is adequate for the transplanting mechanism. With the proposed method, the selectivity of the mechanism’s parameters solution is increased, and transmission performance benefits from the integrated design of trajectory control and the smoothness of the pitch curves.

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Geometric Design and Kinematics Analysis of Non-Circular Planetary Gear Train with Cycloid Profile

JST: Engineering and Technology for Sustainable Development ◽

10.51316/jst.151.etsd.2021.31.3.18 ◽

2021 ◽

Vol 31 (3) ◽

pp. 105-112

Keyword(s):

Numerical Calculation ◽

Planetary Gear ◽

Geometric Design ◽

Gear Train ◽

Variable Speed ◽

Kinematics Analysis ◽

Planetary Gear Train ◽

Mathematical Equations ◽

Simulation Results ◽

Set Up

This research presents a method to design a non-circular planetary gear. Therein the satellite gear block consists of eccentric cycloidal gear and elliptical cycloidal gear, which have been given. The mathematical equations of two ring non-circular gears are set up according to the gearing theory considering the undercutting conditions. A numerical calculation program was written in Matlab to calculate and dynamically analyze this planetary gear. The examples presented in the paper clarified the design steps of the method. The simulation results show that the non-circular cycloidal gear can overcome the irregular tooth phenomenon on the traditional non-circular involute gear, and when it is necessary to design infinitely variable speed converters with large amplitudes, the coefficient λ should be adjusted rather than the coefficient μ.

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Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

Volume 10: ASME 2015 Power Transmission and Gearing Conference; 23rd Reliability, Stress Analysis, and Failure Prevention Conference ◽

10.1115/detc2015-48022 ◽

2015 ◽

Cited By ~ 1

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.

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