Six-bar linkage

In mechanics, a six-bar linkage is a mechanism with one degree of freedom that is constructed from six links and seven joints. An example is the Klann linkage used to drive the legs of a walking machine. In general, each joint of a linkage connects two links, and a binary link supports two joints. If we consider a hexagon constructed from six binary links with six of the seven joints forming its vertices, then the seventh joint can be added to connect two sides of the hexagon to form a six-bar linkage with two ternary links connected by one joint. This type of six-bar linkage is said to have the Watt topology. A six-bar linkage can also be constructed by first assembling five binary links into a pentagon, which uses five of the seven joints, and then completing the linkage by adding a binary link that connects two sides of the pentagon. This again creates two ternary links that are now separated by one or more binary links. This type of six-bar linkage is said to have the Stephenson topology. The Klann linkage has the Stephenson topology. Watt's parallel motion generator consists of the four-bar linkage that has a coupler curve that traces an approximately straight line trajectory, combined with a parallelogram linkage that copies this straight line movement to a desired location. This configuration of six bars and seven joints has two four-bar loops. The six-bars and seven joints of the Stephenson linkage comprise one four-bar loop and one five-bar loop. It has two ternary links that are separated by a binary link. This means the two ternary links are not connected to each other by a joint as in the case of the Watt topology. The Stephenson has three forms depending on the link that is selected as the frame, which are denoted Stephenson I, II and III.

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Five-bar linkage

In kinematics, a five-bar linkage is a mechanism with two degrees of freedom that is constructed from five links that are connected together in a closed chain. All links are connected to each other by five joints in series forming a loop. One of the links is the ground or base. This configuration is also called a pantograph, however, it is not to be confused with the parallelogram-copying linkage pantograph. The linkage can be a one-degree-of-freedom mechanism if two gears are attached to two links and are meshed together, forming a geared five-bar mechanism.

Mécanisme

vignette|Mécanisme d'une crémaillère. Un mécanisme est un assemblage de pièces mécaniques dont certaines peuvent se déplacer par rapport aux autres. Cet assemblage ne constitue donc pas un solide. Chacun de ces mouvements indépendants, ou modes cinématiques, sont appelés degrés de mobilité. Par exemple, le mécanisme d'une montre désigne l'ensemble des ressorts, balancier et engrenages utilisés pour faire tourner les aiguilles. Les mécanismes sont généralement utilisés pour transformer un mouvement en un autre.

Liaison (mécanique)

thumb|Les contacts piston/bielle et piston/chemise peuvent être modélisés par des liaisons pivots. Un mécanisme, ou transmetteur, est l'association de plusieurs pièces liées entre elles par des contacts physiques qui les rendent totalement ou partiellement solidaires, selon qu'ils autorisent ou non des mouvements relatifs des pièces. La liaison mécanique est le modèle de comportement cinématique utilisé pour décrire cette relation, dont la considération est primordiale dans l'étude des mécanismes.

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This paper presents a novel planar four-bar linkage compliant mechanism (called 4-RCC) based on four flexure-based Remote Center of Compliance (RCC) pivots. With particular configurations and dimensions, the beam shortening of the RCC pivots can compensate ...

euspen2022

Statically and dynamically balanced oscillator based on Watt's linkage

Simon Nessim Henein, Hubert Pierre-Marie Benoît Schneegans, Ilan Vardi

We present a new mechanical oscillator architecture that can be made insensitive to linear and angular accelerations while keeping constant oscillation frequency. The oscillator has the kinematics of a Watt linkage, so we call it a Watt oscillator. In orde ...

EUSPEN2020

XY ISOTROPIC HARMONIC OSCILLATOR AND ASSOCIATED TIME BASE WITHOUT ESCAPEMENT OR WITH SIMPLIFIED ESCAPEMENT

Simon Nessim Henein, Ilan Vardi, Lennart Rubbert

The mechanical isotropic harmonic oscillator comprises at least a two degree of freedom linkage supporting an orbiting mass with respect to a fixed base with springs having isotropic and linear restoring force properties. The oscillator may be used in a ti ...

2015

Explore une solution mécanique avec un mécanisme de liaison à quatre barres et un guidage flexible.

Explore le regroupement hiérarchique, les dendrogrammes et diverses fonctions de liaison pour l'agglomération de grappes en fonction de mesures de distance.

Couvre les méthodes de regroupement et les techniques de réduction de dimensionnalité.