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 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.

Research on Calculation of Unloaded Transmission Error of Planetary Gear Train Caused by Eccentricity

2017 ◽  
Author(s):  
Shuaidong Zou ◽  
Guangjian Wang ◽  
Li Yu
Keyword(s):  
Curve Fitting ◽  
Planetary Gear ◽  
Transmission Error ◽  
Gear Train ◽  
Computational Formula ◽  
Planetary Gear Train ◽  
Ratio Error ◽  
Load Transmission ◽  
Planet Gear ◽  
Load Conditions

In this paper, calculation of no-load transmission error (TE) of planetary gear train is studied. The theory computational model of the eccentric planetary gear train with single planet gear (SPG) under no-load conditions is constructed initially for acquiring the formulas of no-load transmission ratio error and unloaded transmission error (UTE) of internal and external gear pairs. Then computational formula of the UTE of planetary gear train with SPG caused by eccentricity is presented. Through simulation TE and the developed formula of UTE, the eccentricities and initial phasing are uncoupled by curve fitting. Simultaneously, formula of UTE of planet gear train with SPG is validated. At the same time, different groups of initial phasing are analyzed to acquire the relatively good initial phasing group. In addition, the UTE of planetary gear train with multiple planet gears (MPG) caused by eccentricity is developed.

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 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.

A Novel Algorithm for Enumeration of the Planetary Gear Train Based on Graph Theory

2011 ◽  
Vol 199-200 ◽  
pp. 392-399 ◽  
Author(s):  
Ming Yue Ma ◽  
Xiang Yang Xu
Keyword(s):  
Graph Theory ◽  
Mechanism Design ◽  
Planetary Gear ◽  
Gear Train ◽  
Enumeration Algorithm ◽  
Planetary Gear Train ◽  
The Core ◽  
Planet Gear ◽  
Gear Trains ◽  
Novel Algorithm

As well known, graph theory is a powerful tool for mechanism design. The enumeration of planet gear trains can be converted the synthesis of graphs while a planetary gear train is converted to a graph. During the enumeration of graphs, the problem of isomorphism should be solved. This paper proposes a novel algorithm used to generate non-isomorphism graphs and thereby omits the part of isomorphism detection. The vertex characteristic is firstly defined in this paper that is the core of the enumeration algorithm. This paper also gives an example of the application for the algorithm.

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.

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