The Conceptual Design of Differential Mechanisms

2013 ◽  
Vol 284-287 ◽  
pp. 973-978
Author(s):  
Chia Chun Chu
Keyword(s):  
Conceptual Design ◽  
Design Process ◽  
Degrees Of Freedom ◽  
Geometric Constraints ◽  
The Other ◽  
Design Approach ◽  
Process Step ◽  
Two Degrees Of Freedom ◽  
Number Synthesis

The purpose of this paper is to present a design approach based on the geometric constraints of joints for synthesizing differential mechanisms with two degrees-of-freedom, including some mechanisms with the same functions but distinct structures. The concept of virtual axes is presented. And, there are five steps in the design process. Step 1 is to decide fundamental entities by the properties of existing mechanisms and the technique of number synthesis, and 10 suitable fundamental entities of differential mechanisms are available. Step 2 is to compose geometric constraints, and 14 items are obtained. Step 3 is to compose links, and 15 items are derived. Step 4 is to assign fixed constraints for inputs or outputs, and 15 results are found. The final step is to particularize the obtained events by the properties of existing mechanisms and the structures of fundamental entities. As a result, 8 feasible results for differential mechanisms with two degrees-of-freedom and two basic loops are obtained in which 2 are existing designs and the other 6 are novel.

Footbridges as an important part of a system: the context as an experience

2021 ◽  
Author(s):  
Toon Maas ◽  
Mohamad Tuffaha ◽  
Laurent Ney
Keyword(s):  
Design Process ◽  
Degrees Of Freedom ◽  
The Other ◽  
Infrastructure Projects ◽  
Good Design ◽  
Cultural Processes ◽  
The Relationship

<p>“A bridge has to be designed”. Every bridge is the exploration of all degrees of a freedom of a project: the context, cultural processes, technology, engineering and industrial skills. A successful bridge aims to dialogue with these degrees of freedom to achieve a delicate equilibrium, one that invites the participation of its users and emotes new perceptions for its viewers. In short, a good design “makes the bridge talk.”</p><p>Too often, the bridge, as an object, is reduced to its functionality. Matters of perceptions and experiences of the users are often not considered in the design process; they are relegated to levels of chance or treated as simple decorative matter. The longevity of infrastructure projects, in general, and bridges, in particular, highlights the deficiencies of such an approach. The framework to design bridges must include historical, cultural, and experiential dimensions. Technology and engineering are of paramount importance but cannot be considered as “an end in themselves but a means to an end”. This paper proposes to discuss three projects by Ney &amp; Partners that illustrate such a comprehensive exploration approach to footbridge design: the Poissy and Albi crossings and the Tintagel footbridge.</p><p>The footbridges of Poissy and Albi dialogue most clearly with their historical contexts, reconfiguring the relationship between old and new in the materiality and typology use. In Tintagel, legend replaces history. Becoming a metaphor for the void it crosses, the Tintagel footbridge illustrates the delicate dialogue of technology and engineering on one side and imagination and experience on the other.</p>

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.

Synthesis of Seven-Link Mechanisms

1973 ◽  
Vol 95 (2) ◽  
pp. 533-540 ◽  
Author(s):  
D. Kohli ◽  
A. H. Soni
Keyword(s):  
Closed Form ◽  
Nonlinear Equations ◽  
Degrees Of Freedom ◽  
The Other ◽  
Linear Superposition ◽  
Two Degrees Of Freedom ◽  
Closed Form Solutions ◽  
Highly Nonlinear ◽  
Principle Of Linear Superposition

The mechanisms derived from the seven-link chains with five links in their two loops and having two degrees of freedom are examined for six synthesis problems. Using displacement matrices, closed form synthesis equations are derived. It is shown that three synthesis problems may be solved using the principle of linear superposition, and closed form solutions may be obtained. The other three synthesis problems involve highly nonlinear equations and must be solved numerically.

Constraint Redundancy in Mobility of Parallel Manipulators

2008 ◽  
Author(s):  
Akhtar N. Malik ◽  
Jian S. Dai ◽  
Gordon R. Pennock
Keyword(s):  
Parallel Manipulator ◽  
Degrees Of Freedom ◽  
Systematic Approach ◽  
Parallel Manipulators ◽  
The Other ◽  
Redundant Constraints ◽  
Parallel Platform ◽  
Number Synthesis ◽  
The Individual ◽  
Three Degree Of Freedom

This paper presents a systematic approach to obtain the degrees of freedom (DOF) of the platforms of parallel manipulators. The paper begins with general Kutzbach criterion for mobility. With simple mathematical transformations this criterion is modified to incorporate number of parallel legs used in the parallel platform-type mechanism and the number of joints in the legs. The theory of screws is used to study the freedom of the joints in the individual legs and the mobility of the platform. It is established that the general Kutzbach mobility criterion does not cater for situations where the freedom screws (or constraint screws) of the joints in a leg become dependent on the freedom screws (or constraint screws) of one or more of the other legs; thus, altering the mobility of the platform. The general modified Kutzbach mobility formula is further modified to resolve the problem of redundant constraints. The paper then provides a systematic approach towards the number synthesis of parallel platform-type mechanims. The paper includes three examples of such mechanisms analyzed by this approach. Results agree with the existing studies carried out on the mechanism used in the examples. A numerical example of a three-degree-of-freedom parallel manipulator with three legs is used to show the enumeration of all possible parallel manipulators. This includes cases with and without redundant constraints.

Two-Degree-of-Freedom Decoupled Nonredundant Cable-Loop-Driven Parallel Mechanism

2013 ◽  
Vol 6 (1) ◽  
Author(s):  
Hanwei Liu ◽  
Clément Gosselin ◽  
Thierry Laliberté
Keyword(s):  
Parallel Mechanism ◽  
Degrees Of Freedom ◽  
Degree Of Freedom ◽  
The Other ◽  
End Effector ◽  
Two Degrees Of Freedom ◽  
Actuation Redundancy ◽  
Rigid Link ◽  
Force Closure ◽  
Two Degree Of Freedom

A novel two-degree-of-freedom (DOF) cable-loop slider-driven parallel mechanism is introduced in this paper. The novelty of the mechanism lies in the fact that no passive rigid-link mechanism or springs are needed to support the end-effector (only cables are connected to the end-effector) while at the same time there is no actuation redundancy in the mechanism. Sliders located on the edges of the workspace are used and actuation redundancy is eliminated while providing force closure everywhere in the workspace. It is shown that the two degrees of freedom of the mechanism are decoupled and only two actuators are needed to control the motion. There are two cable loops for each direction of motion: one acts as the actuating loop while the other is the constraint loop. Due to the simple geometric design, the kinematic and static equations of the mechanism are very compact. The stiffness of the mechanism is also analyzed in the paper. It can be observed that the mechanism's stiffness is much higher than the stiffness of the cables. The proposed mechanism's workspace is essentially equal to its footprint and there are no singularities.

Kinematic Synthesis of Deployable-Foldable Truss Structures Using Graph Theory, Part 1: Graph Generation

1995 ◽  
Vol 117 (1) ◽  
pp. 112-116 ◽  
Author(s):  
D. B. Warnaar ◽  
M. Chew
Keyword(s):  
Graph Theory ◽  
Conceptual Design ◽  
Design Process ◽  
Degrees Of Freedom ◽  
Truss Structure ◽  
Truss Structures ◽  
Structural Synthesis ◽  
Deployable Structures ◽  
Kinematic Synthesis ◽  
Graph Generation

Kinematic structural synthesis has been relatively successful when applied to the conceptual design of mechanisms. The approach presented in this paper, however, views the design process from an initial standpoint of a truss structure. First, graphs are generated that represent truss structures with a given number of nodes and links. Each graph is then modified by designating certain edges in the graph to represent links in the structure that incorporate additional degrees of freedom. In so doing, the graph of a structure is transformed into one representing a mechanism. A procedure is presented that enables the exhaustive generation of these graphs for deployable structures of any given number of nodes and links. From these graphs, it is then possible to obtain enumerable novel deployable truss structures as well as those that have been reported in the literature.

STRUCTURAL SYNTHESIS OF NOVEL BASIC TWO-DOF DIFFERENTIALS

2013 ◽  
Vol 37 (3) ◽  
pp. 713-722
Author(s):  
Chia-Chun Chu
Keyword(s):  
Degrees Of Freedom ◽  
Design Concept ◽  
The Other ◽  
Geometric Constraint ◽  
Graph Representation ◽  
Structural Synthesis ◽  
Two Degrees Of Freedom ◽  
Almost All

Differentials are very important in many crucial applications, but almost all differentials are geared differential mechanisms. Therefore, the main purpose of this paper is to synthesize non-gear or novel differentials. All kinds of basic differentials can be contained in the results by the method. First, a modified graph representation is provided for differential mechanisms with different type. Second, the design concept of composition and decomposition the geometric constraint is presented. Then, ten fundamental entities and seven properties of differentials are collated. Finally, eight feasible results with two degrees-of-freedom and two basic loops are obtained. About the eight results, there are two are existing designs and the other six are novel.

Dynamics of a system of articulated pipes conveying fluid - II. Experiments

1961 ◽  
Vol 261 (1307) ◽  
pp. 487-499 ◽  
Keyword(s):  
Horizontal Plane ◽  
Degrees Of Freedom ◽  
Final Section ◽  
The Other ◽  
Stability Conditions ◽  
Substantial Agreement ◽  
Two Degrees Of Freedom ◽  
Simply Supported ◽  
Pipes Conveying Fluid ◽  
Conveying Fluid

The experiments described here were designed to illustrate general properties examined theoretically in part I, and also to check the theoretical stability conditions that were derived in part I, § 3, for a system having two degrees of freedom. Various assemblies of three articulated pipes were used in the experiments, the first pipe being fixed and the other being free to move in either a vertical or horizontal plane. Both water and air were used as the fluid flowing through the pipes. Three characteristically different forms of instability were observed: buckling when the outlet end was free and when it was simply supported, and amplified oscillations. The observations were in substantial agreement with the theory. The final section of the paper presents a concluding discussion of both parts of this study.

scholarly journals FROM DI-NUCLEUS TO MONO-NUCLEUS: NECK EVOLUTION IN FUSION OF MASSIVE SYSTEMS

2009 ◽  
Vol 18 (10) ◽  
pp. 2169-2174 ◽  
Author(s):  
YASUHISA ABE ◽  
CAIWAN SHEN ◽  
DAVID BOILLEY ◽  
BERTRAND G. GIRAUD
Keyword(s):  
Time Scales ◽  
Heavy Ions ◽  
Degrees Of Freedom ◽  
The Other ◽  
Fusion Process ◽  
Two Degrees Of Freedom ◽  
Mass Asymmetry ◽  
Langevin Approach ◽  
Fluctuation Dynamics ◽  
Three Degrees Of Freedom

Dynamics of the neck degree of freedom during fusioning process between heavy ions is studied. Time scales of the three degrees of freedom (the relative distance, the neck and the mass-asymmetry) are studied, showing an early equilibration of the neck. This means that a di-nucleus formed by the incident combination of ions quickly forms a mono-nucleus with a superdeformation during the fusion process and that the other two degrees of freedom have to be solved in a coupled way. A brief introduction of Langevin approach and dissipation-fluctuation dynamics is also given and of the application to the synthesis of the superheavy elements.

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