Conceptual Design of Gear Differentials for Automotive Vehicles

1994 ◽  
Vol 116 (2) ◽  
pp. 565-570 ◽  
Author(s):  
Hong-Sen Yan ◽  
Long-Chang Hsieh
Keyword(s):  
Conceptual Design ◽  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Gear Train ◽  
Design Constraints ◽  
Two Degrees Of Freedom ◽  
Design Concepts ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Gear Differential

An automotive gear differential is a joint-fractionated planetary gear train with two degrees-of-freedom. We summarize the characteristics of planetary gear trains and the design constraints of noncoupled automotive gear differentials to synthesize their corresponding kinematic graphs. Based on these graphs and the proposed respecializing process, we generate the atlas of design concepts for automotive gear differentials with any types of gear pairs. As a result, there are 4, 25, and 156 design concepts for five-, six-, and seven-bar automotive gear differentials, respectively.

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 GEAR-SHIFTING MECHANISM WITH A ROTARY CONFIGURATION FOR APPLICATIONS IN A 16-SPEED BICYCLE TRANSMISSION HUB

2016 ◽  
Vol 40 (4) ◽  
pp. 597-606
Author(s):  
Yi-Chang Wu ◽  
Li-An Chen
Keyword(s):  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Systematic Design ◽  
Embodiment Design ◽  
Planetary Gear Trains ◽  
Epicyclic Gear ◽  
Gear Mechanism ◽  
Gear Trains ◽  
To Come ◽  
Gear Differential

A multi-speed bicycle transmission hub includes a geared speed-changing mechanism for providing different speed ratios and a gear-shifting mechanism for controlling the gear stage. This paper focuses on the embodiment design of a mechanical gear-shifting mechanism with a rotary configuration used in a 16-speed transmission hub for bicycles. A 16-link, five-degrees of freedom (DOF) split-power epicyclic gear mechanism, which consists of a gear differential and four sets of parallel-connected basic planetary gear trains, is introduced. Based on the clutching sequence table, a systematic design process is developed to come up with the embodiment design of the gear-shifting mechanism. A feasible and compact 16-speed rear transmission hub for bicycles is presented.

SYSTEMATIC METHOD FOR THE SYNTHESIS OF SOUTH POINTING CHARIOT WITH PLANETARY GEAR TRAINS

1996 ◽  
Vol 20 (4) ◽  
pp. 421-435 ◽  
Author(s):  
Long-Chang Hsieh ◽  
Jen-Yu Liu ◽  
Meng-Hui Hsu
Keyword(s):  
Degrees Of Freedom ◽  
Planetary Gear ◽  
Equation Of Motion ◽  
Two Degrees Of Freedom ◽  
Kinematic Design ◽  
Planetary Gear Trains ◽  
Long Time ◽  
Constrained Equations ◽  
Gear Trains ◽  
Mechanical Devices

South pointing chariots have been the fascinating mechanical devices for designers for a long time. Up to date, the gear trains used in the south pointing chariots are the planetary gear trains with two degrees of freedom and with train value -1. The purpose of this work is to present a systematic approach for the kinematic design of south pointing chariots with planetary gear trains. According to train circuit equation, we propose equation of motion of PGTs. Then, based on the equation of motion of PGTs, we derive two constrained equations for the kinematic design of south pointing chariots. Finally, based on these two equations, we synthesize the corresponding south point chariots for arbitrary planetary gear trains with two degrees of freedom. Some design examples are illustrated to demonstrate the design process.

On the Design of Three Links Robot for Drawing Epicycloid and Hypocycloid Curves

2006 ◽  
Author(s):  
Meng-Hui Hsu ◽  
Zong-You Tsai ◽  
Long-Chang Hsieh ◽  
Jen-Yu Liu
Keyword(s):  
Degrees Of Freedom ◽  
Design Method ◽  
Planetary Gear ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Major Type ◽  
Design Constraints ◽  
Two Degrees Of Freedom ◽  
Singular Link ◽  
Angular Velocities

An epicycloid or hypocycloid mechanism is capable of drawing an exact epicycloid or hypocycloid curve. Similar mechanism designs can be found abundantly in industrial machines or educational equipment. Currently, the major type of epicycloid or hypocycloid configurations is planetary gear trains, which contain a binary link that has one fixed and one moving pivot, and a singular link adjacent to the moving pivot. The main feature of the configurations is that any point on the singular link may describe an epicycloid or hypocycloid curve when the binary link is rotated. Presently, the major types of configurations of epicycloid (hypocycloid) mechanisms have one degree of freedom. However, at present, as far as the authors are concerned, there appears to be no approach in designing epicycloid (hypocycloid) mechanisms with two degrees of freedom. Thus, the main aim of this paper is to develop a new design method in designing new configurations of epicycloid (hypocycloid) mechanisms. This paper analyses the characteristics of the topological structures of existing planetary gear train type epicycloid (hypocycloid) mechanisms with one degree of freedom. The equation of motion and kinematical model of the mechanism was derived and appropriate design constraints and criteria were implemented. Subsequently, using the design constraints and criteria, this work designs a new and simple epicycloid (hypocycloid) mechanism that is a three-links robot and has two degrees of freedom. We can easily control the angular velocities of the binary and singular links to satisfy the criterion to draw an epicycloid (hypocycloid) curve. Additionally, an epicycloid (hypocycloid) path of a point on the three links robot is simulated by computer drawing to prove the feasibility of proposed theory. Finally, a prototype of three links robot for drawing an epicycloid (hypocycloid) path is done well. We know the methods of design and manufacture of the proposed epicycloid or hypocycloid mechanism in linkage is easily done.

A New Technique Based on Loops to Investigate Displacement Isomorphism in Planetary Gear Trains

2002 ◽  
Vol 124 (4) ◽  
pp. 662-675 ◽  
Author(s):  
V. V. N. R. Prasad Raju Pathapati ◽  
A. C. Rao
Keyword(s):  
Graph Isomorphism ◽  
Planetary Gear ◽  
Degree Of Freedom ◽  
Gear Train ◽  
Graph Representation ◽  
Kinematic Structure ◽  
Graph Representations ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
A New Technique

The most important step in the structural synthesis of planetary gear trains (PGTs) requires the identification of isomorphism (rotational as well as displacement) between the graphs which represent the kinematic structure of planetary gear train. Previously used methods for identifying graph isomorphism yielded incorrect results. Literature review in this area shows there is inconsistency in results from six link, one degree-of-freedom onwards. The purpose of this paper is to present an efficient methodology through the use of Loop concept and Hamming number concept to detect displacement and rotational isomorphism in PGTs in an unambiguous way. New invariants for rotational graphs and displacement graphs called geared chain hamming strings and geared chain loop hamming strings are developed respectively to identify rotational and displacement isomorphism. This paper also presents a procedure to redraw conventional graph representation that not only clarifies the kinematic structure of a PGT but also averts the problem of pseudo isomorphism. Finally a thorough analysis of existing methods is carried out using the proposed technique and the results in the category of six links one degree-of-freedom are established and an Atlas comprises of graph representations in conventional form as well as in new form is presented.

Signal Flow Graphs for Spatial Gear Trains

1994 ◽  
Vol 116 (1) ◽  
pp. 326-331 ◽  
Author(s):  
R. Ma ◽  
K. C. Gupta
Keyword(s):  
Operations Research ◽  
Equations Of Motion ◽  
Planetary Gear ◽  
Gear Train ◽  
Signal Flow ◽  
Signal Flow Graphs ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
System Variables ◽  
Flow Graphs

Signal flow graphs (SFG) have been applied in many areas such as circuit analysis, controls, mechanical vibrations, statistics, and operations research. They have also been applied to the analysis of planetary gear trains which are planar, i.e., where all of the gear axes are parallel. In this paper, signal flow graphs are applied to spatial planetary gear trains. Some additional terminology and rules which are needed for this important application are developed in this paper and illustrated by examples. The significance of applying SFG to a gear system is that the graph describes the interrelationship among the system variables by linking causes and effects, offers the information about the topology of system connection, and the kinematic equations of motion can be written easily by inspection. In this way, it helps use to visualize and understand spatial gear train systems better.

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.

Investigation of Planet Gear Motion in a Planetary Gear Train With Direct High Speed Monitoring

2018 ◽  
Author(s):  
Tomoki Fukuda ◽  
Masao Nakagawa ◽  
Syota Matsui ◽  
Toshiki Hirogaki ◽  
Eiichi Aoyama
Keyword(s):  
High Speed ◽  
Planetary Gear ◽  
Gear Train ◽  
Improved Method ◽  
Lighting Conditions ◽  
Planetary Gear Trains ◽  
Low Weight ◽  
Torque Capacity ◽  
Planet Gear ◽  
Gear Trains

Planetary gear trains (PGTs) are widely applied in various machines owing to their advantages, such as compactness, low weight, and high torque capacity. However, they experience the problems of vibration due to the structural and motional complexities caused by planet gears. In a previous study, it was shown that high speed monitoring is effective for evaluating the motion of planet gears under steady conditions and transient conditions including the influence of backrush. However graphical investigation was conducted manually, and improvement in accuracy is required. In this report, an improved method is proposed, which includes lighting conditions and measurement conditions. Throughout these improvement processes, instant center of rotation is calculated automatically with detected coordinates using software. This makes it possible to estimate the transient response of PGTs with planet gear motion.

The Analysis of Planetary Gear Trains

2010 ◽  
Vol 2 (2) ◽  
Author(s):  
Madhusudan Raghavan
Keyword(s):  
Planetary Gear ◽  
Gear Train ◽  
Compact Representation ◽  
Planetary Gear Train ◽  
Traditional Concept ◽  
Planetary Gear Trains ◽  
Gear Trains ◽  
Large Families ◽  
Case Basis

The generalized lever is a new tool in gear train representation. It extends the traditional concept of a lever representation of a planetary gear set to 1 that includes negative lever ratios. This allows an exhaustive permutation of the nodes of a lever, thereby leading to all possible topological arrangements of a planetary gear train. Consequently, we achieve a compact representation of large families of planetary gear trains, which would otherwise have to be dealt with on a case-by-case basis.

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