Analysis of epicyclic gear train with deformable ring

1989 ◽  
Vol 24 (5) ◽  
pp. 363-372 ◽  
Author(s):  
T.A Stolarski
Keyword(s):  
Gear Train ◽  
Epicyclic Gear

Topological Synthesis of Epicyclic Gear Trains Using Vertex Incidence Polynomial

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Vinjamuri Venkata Kamesh ◽  
Kuchibhotla Mallikarjuna Rao ◽  
Annambhotla Balaji Srinivasa Rao
Keyword(s):  
High Velocity ◽  
Mechanical Energy ◽  
Gear Train ◽  
Recursive Method ◽  
Gear Pair ◽  
Simple Method ◽  
Epicyclic Gear ◽  
Thick Line ◽  
Gear Trains ◽  
Isomorphic Graphs

Epicyclic gear trains (EGTs) are used in the mechanical energy transmission systems where high velocity ratios are needed in a compact space. It is necessary to eliminate duplicate structures in the initial stages of enumeration. In this paper, a novel and simple method is proposed using a parameter, Vertex Incidence Polynomial (VIP), to synthesize epicyclic gear trains up to six links eliminating all isomorphic gear trains. Each epicyclic gear train is represented as a graph by denoting gear pair with thick line and transfer pair with thin line. All the permissible graphs of epicyclic gear trains from the fundamental principles are generated by the recursive method. Isomorphic graphs are identified by calculating VIP. Another parameter “Rotation Index” (RI) is proposed to detect rotational isomorphism. It is found that there are six nonisomorphic rotation graphs for five-link one degree-of-freedom (1-DOF) and 26 graphs for six-link 1-DOF EGTs from which all the nonisomorphic displacement graphs can be derived by adding the transfer vertices for each combination. The proposed method proved to be successful in clustering all the isomorphic structures into a group, which in turn checked for rotational isomorphism. This method is very easy to understand and allows performing isomorphism test in epicyclic gear trains.

Design of an Epicyclic Transmission for Speed Control of a Turbine-Generator System

1992 ◽  
Author(s):  
Indranil Barman ◽  
Donald R. Flugrad
Keyword(s):  
Control Method ◽  
Equations Of Motion ◽  
Speed Control ◽  
Gear Train ◽  
Turbine Generator ◽  
Generator System ◽  
Epicyclic Gear ◽  
The Face ◽  
Fine Control ◽  
Parameter Values

Abstract An improved speed control method is proposed for a turbine-generator system. Whereas the present method employs a steam valve to control the flow of steam according to the desired output, the proposed system uses an epicyclic gear train to provide fine control of the speed, while coarse control is still maintained through the steam valve. The systematic design of such a gear train is the objective of this project. Two configurations are considered as suitable candidates. After the transmissions are analyzed to obtain the speed and torque relations, the dynamic equations of motion and control equations for the systems are derived for simulation purposes. The simulations are then conducted for various load cases and parameter values to determine a suitable design for application in the power industry. The final configuration allows constant generator output speeds to be reliably maintained in the face of significant load disturbances.

Meshing Efficiency Analysis of Two Degree-of-Freedom Epicyclic Gear Trains

2016 ◽  
Vol 138 (8) ◽  
Author(s):  
Essam Lauibi Esmail
Keyword(s):  
Reference Frame ◽  
Power Efficiency ◽  
Power Flow ◽  
Flow Direction ◽  
Efficiency Analysis ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
Two Degree Of Freedom

The concept of potential power efficiency is introduced as the efficiency of an epicyclic gear train (EGT) measured in any moving reference frame. The conventional efficiency can be computed in a carrier-moving reference frame in which the gear carrier appears relatively fixed. In principle, by attaching the reference frame to an appropriate link, torques can be calculated with respect to each input, output, or (relatively) fixed link in the EGT. Once the power flow direction is obtained from the potential power ratio, the torque ratios are obtained from the potential power efficiencies, the particular expression of the efficiency of the EGT is found in a simple manner. A systematic methodology for the efficiency analysis of one and two degree-of-freedom (DOF) EGTs is described, and 14 ready-to-use efficiency formulas are derived for 2DOF gear pair entities (GPEs). This paper includes also a discussion on the redundancy of the efficiency formulas used for 1DOF GPEs. An incomplete in the efficiency formulas in previous literature, which make them susceptible to wrong application, is brought to light.

Flow-graph techniques for epicyclic gear train analysis†

1973 ◽  
Vol 17 (2) ◽  
pp. 263-272 ◽  
Author(s):  
H. S. NAGARAJ ◽  
R. HARIHARAN
Keyword(s):  
Gear Train ◽  
Flow Graph ◽  
Epicyclic Gear

A step-up epicyclic gear-train and flowgraph analysis†

1973 ◽  
Vol 17 (5) ◽  
pp. 1059-1063
Author(s):  
H. S. NAGARAJ ◽  
R. HARIHARAN
Keyword(s):  
Gear Train ◽  
Epicyclic Gear

Theoretic Study of Efficiency of Two-DOFs of Epicyclic Gear Transmission via Virtual Power

2011 ◽  
Vol 133 (3) ◽  
Author(s):  
Chao Chen ◽  
Teck Teh Liang
Keyword(s):  
Design Optimization ◽  
Fundamental Form ◽  
Degrees Of Freedom ◽  
Gear Transmission ◽  
Gear Train ◽  
Mechanical Transmission ◽  
Virtual Power ◽  
Two Degrees Of Freedom ◽  
Analytical Expression ◽  
Epicyclic Gear

Epicyclic gear train is a fundamental form of mechanical transmission with broad applications. Efficiency study of these trains is critical to design, optimization, and operation. It is known that the efficiencies of these systems are highly related to the internal power flows. We apply the concept of virtual power to find analytical expression of the efficiency of a two degrees of freedom train, with associated applicable ranges. The results are verified by an example.

Cycloid Drives With Machining Tolerances

1989 ◽  
Vol 111 (3) ◽  
pp. 337-344 ◽  
Author(s):  
J. G. Blanche ◽  
D. C. H. Yang
Keyword(s):  
High Efficiency ◽  
Dynamic Instability ◽  
Torque Ripple ◽  
Gear Train ◽  
Space Applications ◽  
Input Shaft ◽  
Epicyclic Gear ◽  
Speed Reducer ◽  
Planet Gear ◽  
Gear Mechanism

The cycloidal speed reducer, or cycloid drive, is an epicyclic gear train in which the profile of the planet gear is an epitrochoid and the annular sun gear has rollers as its teeth. The cycloid drive has very high efficiency and small size, in comparison with a conventional gear mechanism, making it an attractive candidate for limited space applications. On the other hand, in this type of transmissions there exist two major drawbacks, namely, backlash and torque ripple. Backlash, the angle through which the output shaft can rotate when the input shaft is held fixed, has a degrading effect on the output accuracy. Torque ripple, the variation in mechanical advantage as the input shaft rotates, causes vibrations and could lead to dynamic instability of the machinery. If the cycloid drive were manufactured to the ideal dimensions, there would be no backlash nor torque ripple. However, in reality, there will always be some machining tolerances. In this paper an analytical model is developed which models the cycloid drive with machining tolerances. Consequently, the effect of machining tolerances on backlash and torque ripple are investigated. It is found that both the backlash and the torque ripple are inherent periodic functions of the input crank angle.

Simplified modellization of gear micropitting

2002 ◽  
Vol 216 (6) ◽  
pp. 291-302 ◽  
Author(s):  
F Antoine ◽  
J-M Besson
Keyword(s):  
Film Thickness ◽  
Thermochemical Treatment ◽  
Gear Train ◽  
Surface Finishing ◽  
Case Hardening ◽  
Reference Case ◽  
Oil Film ◽  
Epicyclic Gear ◽  
Wide Range ◽  
Physical Phenomena

This document gives a simplified method of calculating gear micropitting. The method has been developed by EUROCOPTER. The objective was to provide a model that took into consideration the maximum number of parameters in order to model the different physical phenomena, particularly: an oil-film thickness calculation taking the influence of pressure into consideration a simplified modellization of roughness an estimation of the plastification effect on the roughness overpressure at the contact surface taking into account the combined effects of roughness and oil-film thickness. The elaborated model is presented in an Excel file form. The application program is called APICS (approche du pitting par calculs simplifiés). In order to validate this model, this program has been applied to: An epicyclic gear train of a helicopter. Tests on discs as part of the ASETT European program. Discs are in hardened M50NiL Duplex (surface treatment: carburized and nitrided). Different kinds of surface finishing were proposed. The reference case of discs in 16NCD13 without thermochemical treatment has been also treated. FZG gear benchtests, also as part of the ASETT program. Gears have been manufactured in hardened M50NiL Duplex, with different kinds of surface finishing proposed. The results of the calculations express quite exactly the experimental facts observed on discs and gears for a wide range of studied cases, covering different materials, different kinds of case hardening and different kinds of surface finishing.

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