scholarly journals Patent Analysis and Structural Synthesis of Epicyclic Gear Trains Used in Automatic Transmissions

2019 ◽  
Vol 10 (1) ◽  
pp. 82 ◽  
Author(s):  
Huafeng Ding ◽  
Changwang Cai
Keyword(s):  
Structural Characteristics ◽  
Main Shaft ◽  
Structural Synthesis ◽  
New Approach ◽  
Automatic Transmissions ◽  
Epicyclic Gear ◽  
Transformation Relation ◽  
Gear Trains ◽  
Basic Graph ◽  
Patent Survey

A patent survey is conducted to investigate the application status of epicyclic gear trains (EGTs) used in automatic transmissions (ATs). In this regard, 673 AT patents are investigated firstly, and 274 different EGTs are obtained after the patent processing. EGTs are presented by corresponding double bicolor graphs (DBGs) and they are sorted into 13 groups in accordance with the degree of freedom (DOF) of DBGs and the degree of hollow vertices. Then, structural characteristics of obtained EGTs, which are used to detect whether the EGTs obtained in the future can be used in ATs, are analyzed and summarized. Finally, a new approach is proposed to obtain new configurations of the EGTs with one main shaft based on the transformation relation between DBG and the basic graph. Several examples are presented to illustrate the validity of the proposed approach.

Automatic Structural Synthesis of Epicyclic Gear Trains With One Main Shaft

2015 ◽  
Author(s):  
Huafeng Ding ◽  
Shuai Liu ◽  
Peng Huang ◽  
Changwang Cai ◽  
Zhen Huang
Keyword(s):  
Automobile Industry ◽  
Structural Characteristics ◽  
Graph Representation ◽  
Synthesis Process ◽  
Automatic Method ◽  
Main Shaft ◽  
Topological Graphs ◽  
Epicyclic Gear ◽  
Adjacency Matrices ◽  
Gear Trains

Design of automatic gear boxes with better performance is a pursuit goal of the modern automobile industry. In order to develop CAD method for the creative design of automatic gear boxes, this paper proposes an automatic method for the structure synthesis of one degree of freedom (DOF) epicyclic gear trains (EGTs) with one main shaft which serve as the key mechanisms in automatic gear boxes. First, based on the graph representation of EGTs, the canonical perimeter graphs and the corresponding canonical adjacency matrices are obtained. Then, based on the canonical adjacency matrices, the characteristic number strings are obtained and used to identify isomorphism in the synthesis process. Third, an automatic method is proposed to generate the basic graphs of the topological graphs of EGTs, and the basic graphs up to 9 links are synthesized. After that, based on the structural characteristics for the graphs of EGTs, an automatic method is proposed to synthesize the topological graphs of EGTs from the basic graphs, and an algorithm for the detection of rigid subchains in EGTs is also presented. Finally, a program is developed, and 1-DOF EGTs having one main shaft with up to 9 links are synthesized.

Epicyclic gear trains for automotive automatic transmissions

2000 ◽  
Vol 214 (5) ◽  
pp. 523-532 ◽  
Author(s):  
C-H Hsu ◽  
J-J Hsu
Keyword(s):  
Adjacency Matrix ◽  
Gear Train ◽  
Graph Representation ◽  
Structural Synthesis ◽  
Automatic Transmissions ◽  
Epicyclic Gear ◽  
Systematic Methodology ◽  
Gear Trains ◽  
Configuration Synthesis ◽  
Admissible Graph

Epicyclic gear trains, which contain at least four coaxial links, are widely used in automatic transmissions. This paper presents a systematic methodology for the synthesis of epicyclic gear trains for automotive automatic transmissions. The graph representation of epicyclic gear trains is applied to develop an approach for the structural synthesis of the graphs of admissible epicyclic gear trains. Next, for each admissible graph the adjacency matrix of an epicyclic gear train is defined to develop an algorithm for the configuration synthesis of epicyclic gear trains. Using the proposed algorithm, all possible epicyclic gear trains for automotive automatic transmissions are systematically synthesized. In this paper, admissible epicyclic gear trains with up to ten links have been successfully synthesized. The results of work will lead to the creation of new multispeed automotive automatic transmissions.

Innovation Synthesis of Basic Configurationof Epicyclic Gear Trains with Three-Degrees of Freedom

2011 ◽  
Vol 199-200 ◽  
pp. 358-364
Author(s):  
Heng Bin Ren ◽  
Mao Lin Huang
Keyword(s):  
Degrees Of Freedom ◽  
Synthesis Method ◽  
Kinematic Chain ◽  
Practical Application ◽  
New Approach ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
Train System ◽  
Three Degrees Of Freedom ◽  
Basic Configuration

Epicyclical gear trains with three-degrees of freedom have found its wide application as the development of new technique. Currently, nearly all domestic researches on epicyclical gear trains with three or more degrees of freedom are aimed at the practical application, and scare works systematically investigate basic configuration and synthesis of the train system. An innovation synthesis method is proposed based on the compound joint kinematic chain and the substitution of low pair with high pair for epicyclical gear trains with three-degrees of freedom, and the possible independent basic configurations of epicyclical gear trains with three-degrees of freedom are obtained by applying the proposed method and the utilization of the method is also discussed. The method provides not only a new approach for innovation synthesis of epicyclical gear trains but also a few basic configurations of epicyclical gear trains with three-degrees of freedom for practice design.

Simplified Kinematic Analysis of Bevel Epicyclic Gear Trains With Application to Power-Flow and Efficiency Analyses

2005 ◽  
Vol 127 (2) ◽  
pp. 278-286 ◽  
Author(s):  
Carl A. Nelson ◽  
Raymond J. Cipra
Keyword(s):  
Graph Theory ◽  
Kinematic Analysis ◽  
Power Flow ◽  
Computer Software ◽  
Input And Output ◽  
Automatic Transmissions ◽  
Epicyclic Gear ◽  
Analysis Technique ◽  
Angular Velocities ◽  
Gear Trains

A kinematic analysis technique is introduced to find the angular velocities of all links in bevel epicyclic gear trains. The method relies on previous work in graph theory. It improves on existing techniques used for analysis of planar geared mechanisms in its ability to accurately solve the kinematics of spatial geared mechanisms, particularly bevel gear trains, in a simpler manner. Usefulness of the method is demonstrated through its application to power-flow and efficiency analyses as well as its implementation in computer software. This discussion is limited to gear trains whose input and output axes are collinear, such as automotive automatic transmissions.

A Combinatorial Approach for the Automatic Sketching of Planar Kinematic Chains and Epicyclic Gear Trains

1990 ◽  
Vol 112 (1) ◽  
pp. 6-15 ◽  
Author(s):  
Wei-Hua Chieng ◽  
D. A. Hoeltzel
Keyword(s):  
Graph Representation ◽  
Combinatorial Approach ◽  
New Approach ◽  
Kinematic Chains ◽  
Constrained Problem ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
Automatic Mechanism ◽  
Diagram Representation ◽  
Number Of Authors

Automatic mechanism sketching can be considered to be a computational approach for converting the graph representation of a mechanism into its skeleton diagram representation, subject to the constraint of the avoidance of crossing links. The purpose of sketching is to obtain a clearer understanding of the topological and functional characteristics of a mechanism. Since the avoidance of link crossing alone cannot provide control over the numerical solution to the sketching problem, the graph-to-mechanism conversion process, subject to the constraint of link crossing avoidance, can be classified as an ill-constrained problem. The application of heuristics and semi-algorithmic methods have been applied by a number of authors in an attempt to overcome this numerical barrier. This paper introduces a new computational model, based on a combinatorial approach, for algorithmically solving the numerically continuous mechanism sketching problem as a discrete domain problem. This new approach can systematically generate explicit, concrete sketching constraints, thereby providing a well defined methodology for mechanism sketching.

An Application of Generalized Kinematic Chains to the Structural Synthesis of Nonfractionated Epicyclic Gear Trains

1992 ◽  
Author(s):  
Cheng-Ho Hsu
Keyword(s):  
Degrees Of Freedom ◽  
Systematic Approach ◽  
Kinematic Chain ◽  
Structural Synthesis ◽  
Kinematic Chains ◽  
Epicyclic Gear ◽  
Gear Trains ◽  
Three Degrees Of Freedom

Abstract This paper presents a systematic approach, which is based on the concept of generalization for the structural synthesis of geared kinematic chains for epicyclic gear trains with any number of degrees of freedom. First, the fundamental rules of generalized kinematic chains for nonfractionated epicyclic gear trains are investigated. Next, according to the numbers of gear pairs and degrees of freedom, acceptable kinematic chains for nonfractionated epicyclic gear trains are identified from an atlas of basic kinematic chains. Then, each acceptable kinematic chain is specialized to be epicyclic gear trains. Finally, geared kinematic chains for nonfractionated epicyclic gear trains with up to three degrees of freedom and four gear pairs have been susscessfully constructed.

Structural Synthesis and Enumeration of Epicyclic Gear Mechanisms Up to 12-Links Using Acyclic Graph Method

2006 ◽  
Author(s):  
M. S. El-Gayyar ◽  
H. M. El-Eashy ◽  
M. Zaki
Keyword(s):  
Computer Program ◽  
Automatic Detection ◽  
Structural Synthesis ◽  
New Approach ◽  
Acyclic Graph ◽  
Graph Method ◽  
Epicyclic Gear ◽  
Adjacency Matrices ◽  
Isomorphic Graphs

In this paper, a new approach for graphical enumeration of epicyclic gear mechanisms is presented using the concept of acyclic graph. A new graphical code has been introduced to specify the priorities of all vertices of associated displacement graph. This graphical code is used to identify open graph, redundant links and isomorphic graphs. A computer program has been developed for automatic enumeration of displacement graphs as well as automatic detection of isomorphic graphs and open graphs and graphs with a redundant link without using adjacency matrices. This simplified methodology has been applied for the enumeration of epicyclic gear mechanisms with up to 12-links having up to 9 coaxial links. An atlas for 11 and 12-link mechanisms has been constructed using the proposed methodology.

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