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.

Conditions for Self-Locking in Planetary Gear Trains

2006 ◽  
Vol 129 (9) ◽  
pp. 960-968 ◽  
Author(s):  
David R. Salgado ◽  
J. M. del Castillo
Keyword(s):  
Planetary Gear ◽  
Degree Of Freedom ◽  
The Self ◽  
Gear Train ◽  
Planetary Gear Train ◽  
Analytical Expression ◽  
Planetary Gear Trains ◽  
Input And Output ◽  
Approximate Relationship ◽  
Gear Trains

The objective of the present work is to determine the conditions that have to be satisfied for a planetary gear train of one degree of freedom to be self-locking. All planetary gear trains of up to six members are considered. As a result, we show the constructional solutions of planetary gear trains exhibiting self-locking. Unlike other studies, the self-locking conditions are obtained systematically from the analytical expression for the product of the efficiency of a given train by the efficiency of the train resulting from interchanging its input and output axes. Finally, a proof is given of an approximate relationship between these two efficiencies.

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.

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.

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.

Study on Characteristics of Metal V-Belt Infinitely Variable Power-Split Transmission

2011 ◽  
Vol 383-390 ◽  
pp. 785-789 ◽  
Author(s):  
Hui Pan ◽  
Xing Cai
Keyword(s):  
Planetary Gear ◽  
Gear Ratio ◽  
Gear Transmission ◽  
Gear Train ◽  
Speed Ratio ◽  
Planetary Gear Train ◽  
Power Split ◽  
In Series ◽  
Variable Power ◽  
Changing Rate

Six kinds of torque-splitting and speed-converging metal V-belt IVPST were raised; their global speed ratio and torque ratio of metal V-belt CVT output to metal V-belt IVPST output were derived. Two different torque-splitting and speed-converging metal V-belt IVPSTs were sum up: series and parallel metal V-belt IVPSTs. In series metal V-belt IVPST, speed ratio changing rate and torque ratio were related to gear ratio of planetary gear train and fixed gear transmission, but in parallel metal V-belt IVPST, that were only related to gear ratio of planetary gear train.

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 The Trajectory Analysis of Bevel Planetary Gear Trains

1991 ◽  
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

Abstract 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.

Investigation of Power Transmission Mechanism Under Three-Axis Driving Planetary Gear Train Based on the Mechanism

2016 ◽  
Author(s):  
Masao Nakagawa ◽  
Dai Nishida ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
Power Transmission ◽  
Structural Complexity ◽  
Planetary Gear ◽  
Gear Train ◽  
Experimental Result ◽  
Planetary Gear Train ◽  
Planetary Gear Trains ◽  
Planet Gear ◽  
Gear Trains ◽  
Driving Condition

Planetary gear trains are presently widely used in various machines owing to their many advantages. They, however, suffer from problems of noise and vibration due to their structural complexity. Moreover, their dynamic characteristics are yet to be fully understood. Although several studies have been conducted on two-axis driving and displacement of planet gear, none has considered three-axis driving. In the present study, the general driving conditions of a planetary gear train, including during three-axis driving, were investigated based on the theory of instant center. Ideal driving condition is proposed based on the experimental result on three-axis driving which was tested on an original fully wireless test stand.

Dynamic Characteristics of Double Helical Planetary Gear Train With Tooth Friction

2015 ◽  
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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