Novel approach for planetary gear train dimensional synthesis through kinematic mapping

2019 ◽  
Vol 234 (1) ◽  
pp. 273-288 ◽  
Author(s):  
Liang Sun ◽  
Zhenfei Wang ◽  
Chuanyu Wu ◽  
Guofeng Zhang
Keyword(s):  
Angular Displacement ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Gear Train ◽  
Transmission Ratio ◽  
Dimensional Synthesis ◽  
Open Chain ◽  
Planetary Gear Train ◽  
Kinematic Mapping ◽  
Noncircular Gears

The synthesis of a kinematic trajectory traversed by an output link (planet gear) and posture of a planetary gear train with noncircular gears can be divided into two phases: dimensional synthesis of the open-chain 2R mechanism (planetary carrier) and optimization of the transmission ratio of noncircular gear pairs. According to kinematic mapping theory, more than one closed coupler trajectory can be obtained by five preset poses. Simultaneous consideration of the trajectory shape, posture, and gear ratio is difficult during planetary gear train synthesis. This work therefore proposes a new method for the synthesis of planetary gear train in which different path segments in different trajectories are selected and a group of same-type 2R mechanisms is employed to pass through them in order to rebuild a new, closed trajectory. Subsequently, the transmission ratio of noncircular gear pairs can be determined using the relative angular displacement of the 2R mechanism. To improve the roundness of the pitch curves of noncircular gears, two optimization steps are implemented using a genetic algorithm without alternating the data points of the requisite open trajectories. For example, a mechanism for rice pot seedling transplanting is obtained by using the method.

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

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.

Analysis and Design of a Spatial Planetary Noncircular Gear Train for Rice Seedling Transplanting Based on Three Given Positions

2020 ◽  
Vol 63 (1) ◽  
pp. 165-176
Author(s):  
Liang Sun ◽  
Yuzhu Zhou ◽  
Hengmin Huang ◽  
Chuanyu Wu ◽  
Guofeng Zhang
Keyword(s):  
Lateral Displacement ◽  
Kinematic Model ◽  
Planetary Gear ◽  
Gear Train ◽  
Transmission Ratio ◽  
List Type ◽  
Gear Pair ◽  
Planetary Gear Train ◽  
Analysis And Design ◽  
Noncircular Gears

HighlightsA method for solving a spatial transplanting mechanism with noncircular gears is proposed.A new mechanism for transplanting rice pot seedlings is proposed.A trajectory with a small lateral displacement at the preparation phase is obtained.The working performance is validated by simulations and field tests.Abstract. This study proposes a method of solving the parameters of a spatial planetary gear train with noncircular gears to meet the requirements of wide-narrow row pot seedling transplanting (WPST). First, the planetary gear train was simplified to a spatial open-chain 2R mechanism (planetary carrier). A kinematic model of the 2R mechanism was derived from the three given homogeneous matrices describing the spatial position and attitude information of grasping, extracting, and planting seedlings. Second, the length of each link, attitude of each rotation axis, and relative initial angles were calculated. The model for solving the transmission ratio was deduced. A spatial planetary gear train configuration with a single planet carrier and two-stage driving was derived, in which the middle axis could be determined by combining the selected configuration, represented trajectory, and transmission ratio of each gear pair. Finally, a planetary gear train combining a noncircular gear pair and a helical gear pair was used in the WPST mechanism design. Simulations and tests conducted on a prototype confirmed the correctness of the theoretical model and the practicality of the design. Keywords: Noncircular gear, Planetary gear train, Spatial trajectory, Transmission ratio, Transplanting mechanism.

scholarly journals Work of the planetary gear trains as differentials and their capabilities

2019 ◽  
Vol 287 ◽  
pp. 04001
Author(s):  
Kiril Arnaudov ◽  
Stefan Petrov ◽  
Emiliyan Hristov
Keyword(s):  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Gear Train ◽  
Motor Drive ◽  
Planetary Gear Train ◽  
Maximum Security ◽  
Single Carrier ◽  
Planetary Gear Trains ◽  
Gear Trains

Planetary gear trains can work differently, namely, with F=1 degree of freedom, i.e. as reducers or multipliers, and also with F=2 degrees of freedom, i.e. as differentials. Moreover, with a two-motor drive they work as a summation planetary gear train and with a one-motor drive, they work as a division planetary gear train. The most popular application of planetary gear trains is as a differential which is bevel and is produced globally in millions of pieces. Some of the cylindrical planetary gear trains can also be used as differentials. Although less often, they are used in heavy wheeled and chain vehicles such as trailer trucks, tractors and tanks. They are also very suitable for lifting machines with a two-motor drive which provides maximum security for the most responsible cranes, such as the metallurgical ones. Initially the paper presents some simple, i.e. single-carrier cylindrical planetary gear trains, both with external and internal meshing, driven by 2 motors. Their kinematic capabilities and velocity, respectively, are considered to realize the necessary gear ratio. Finally, the case of a compound two-carrier planetary gear train is considered, which is composed of 2 simple planetary gear trains. This shows that not only the simple planetary gear trains, i.e. the single-carrier ones, can work as differentials.

Novel Gear Transmission Mechanism With Twice Unequal Amplitude Transmission Ratio

2019 ◽  
Vol 141 (9) ◽  
Author(s):  
Gaohong Yu ◽  
Zhipeng Tong ◽  
Liang Sun ◽  
Junhua Tong ◽  
Xiong Zhao
Keyword(s):  
Structural Characteristics ◽  
Angular Displacement ◽  
Planetary Gear ◽  
Gear Transmission ◽  
Transmission Mechanism ◽  
Gear Train ◽  
Transmission Ratio ◽  
Gear Pair ◽  
Pitch Curve ◽  
Gear Rack

The operation effectiveness of multi-bar transplanting mechanisms is low, and the specific changing law of the transmission ratio (the curve of the transmission ratio has twice unequal amplitude [TUA] fluctuation.), which is needed in vegetable pot seedling transplanting, is difficult to fulfill using a planetary gear train with noncircular gears and a single-planet carrier. To address this problem, we propose a noncircular gear pair that comprises an incomplete noncircular gear, rack, partial noncircular gear, and elliptical gear. The structural characteristics and the working principle of the TUA gear pair were analyzed. The pitch curve equation of the noncircular TUA gears was derived from the relationship of the angular displacement of the corresponding pitch curves. The influence of central angle α and eccentricity k on the shape of the pitch curve, angular displacement, and transmission ratio of the TUA gear pair was analyzed. The TUA gear pair was applied to a proposed vegetable seedling pickup mechanism (SPM) considering the design requirements. Finally, the feasibility of the new noncircular TUA gear transmission mechanism was verified by an SPM test.

A novel planar motion generation method based on the synthesis of planetary gear train with noncircular gears

2019 ◽  
Vol 33 (10) ◽  
pp. 4939-4949 ◽  
Author(s):  
Jun Ye ◽  
Xiong Zhao ◽  
Ying Wang ◽  
XinCheng Sun ◽  
JianNeng Chen ◽  
...  
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Planar Motion ◽  
Motion Generation ◽  
Planetary Gear Train ◽  
Noncircular Gears

A PLANETARY GEAR TRAIN WITH RING-INVOLUTE TOOTH

2008 ◽  
Vol 32 (2) ◽  
pp. 251-266
Author(s):  
Shyue-Cheng Yang ◽  
Tsang-Lang Liang
Keyword(s):  
Planetary Gear ◽  
Conjugate Problem ◽  
Gear Ratio ◽  
Gear Train ◽  
Tooth Surface ◽  
The Sun ◽  
Ring Gear ◽  
Planetary Gear Train ◽  
Envelope Method ◽  
Planet Gear

This paper proposes a planetary gear train with ring-involute tooth profile. Inherent in a planetary gear train is the conjugate problem among the sun, the planet gears and the ring gear. The sun gear and the planet gear can be obtained by applying the envelope method to a one-parameter family of a conical tooth surface. The conical tooth rack cutter was presented in a previous paper [5]. The obtained planet gear then becomes the generating surface. The double envelope method can be used to obtain the envelope to the family of generating surfaces. Subsequently the profile of a ring gear of the planetary gear trains can be easily obtained, and using the generated planet gear and applying the gear theory, the ring gear is generated. To illustrate, the planetary gear train with a gear ratio of 24:10:7 is presented. Using rapid prototyping and manufacturing technology, a sun gear, four planet gears, and a ring gear are designed. The RP primitives provide an actual full-size physical model that can be analyzed and used for further development. Results from these mathematical models are applicable to the design of a planetary gear train.

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.

scholarly journals The Trajectory Analysis of Bevel Planetary Gear Trains

1993 ◽  
Vol 115 (1) ◽  
pp. 164-170 ◽  
Author(s):  
Chen-Chou Lin ◽  
Lung-Wen Tsai
Keyword(s):  
Trajectory Analysis ◽  
Planetary Gear ◽  
Gear Ratio ◽  
Point Of View ◽  
Gear Train ◽  
Geometric Description ◽  
Planetary Gear Train ◽  
Planetary Gear Trains ◽  
Gear Trains

In this paper, the trajectory of bevel planetary gear trains has been studied. The parametric equations of trajectory are derived. It is shown that the trajectory generated by a tracer point on the planet of a bevel planetary gear train is analogous to that of a spur planetary gear train. Two cases, gear ratio equal to one and two, are presented in detail including the geometric description, plane of symmetry, extent of trajectory, number of nodes (cusps) and their locations. The criteria for the existence of cusps are verified algebraically, and interpreted from geometrical point of view.

Self-Locking of 2S-C Type Planetary Gear Train Composed of External Gears

2009 ◽  
Author(s):  
Kiyotaka Ikejo ◽  
Kazuteru Nagamura ◽  
Tuneji Yada ◽  
Yoshiya Kagari
Keyword(s):  
Planetary Gear ◽  
Gear Ratio ◽  
The Self ◽  
Gear Train ◽  
Experimental Result ◽  
Lower Efficiency ◽  
Planetary Gear Train ◽  
Practical Test ◽  
Low Efficiency

A planetary gear train is used in a transmission in many fields, because it has a smaller size, a lighter weight, and a larger gear ratio than a conventional gear train. However, a planetary gear train has a lower efficiency than a conventional gear train. Self-locking sometimes occurs, in which case the planetary gear train can not be driven, because of a significant low efficiency. In this study, we theoretically analyzed the efficiency of a 2S-C type planetary gear train composed of external gears, and presented the condition in which the self-locking occurs. Furthermore, we examined the self-locking of 2S-C type planetary gear train composed of external gears using several gear sets with different numbers of teeth by the practical test. As the result, the condition of the self-locking which was analyzed theoretically agreed with experimental result.

ON THE NEW MECHANICAL PRESS WITH A PLANETARY GEAR TRAIN

2016 ◽  
Vol 40 (1) ◽  
pp. 45-58 ◽  
Author(s):  
Ren-Chung Soong
Keyword(s):  
Dynamic Performance ◽  
Planetary Gear ◽  
Cost Effective ◽  
Gear Train ◽  
Dimensional Synthesis ◽  
Linkage Mechanism ◽  
Planetary Gear Train ◽  
The Press ◽  
Mechanical Press ◽  
Crank Mechanism

A new 1-DOF mechanical press with a geared eight-bar linkage mechanism is presented. The proposed press can generate the required kinematic and dynamic performance for drawing, stamping, deep drawing, and precision cutting processes by simply adjusting the offset of the ram. The press consists of an elementary planetary gear train with a pair of planet gears, a slider-crank mechanism, and a slider-crank mechanism with a variable-length crank. The configuration and a solid model are described, and a kinematic analysis, dynamic analysis, and optimized dimensional synthesis of the press are discussed. Examples are provided to verify the feasibility and effectiveness of the design methodology. The proposed press could lead to more flexible and cost-effective applications.

Sign in / Sign up

Export Citation Format

Share Document