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linkage

LINK-ij /ˈlɪŋkɪdʒ/

nounC1GRETOEFL

TechnicalProfessional

An assembly of bodies (links) connected to manage forces and movement.

A linkage is a collection of rigid links connected by joints (like pins or hinges) to form a closed chain. It is used to convert one type of motion into another (e.g., converting the circular motion of a motor into the back-and-forth motion of a windshield wiper).

The story behind the word. The word 'link' comes from an old Scandinavian word for a loop of a chain. In the 19th century, as mechanical engineering became a formalized science, the suffix '-age' (denoting a collection or system) was added to create 'linkage', describing a system of connected bars used to transmit motion.

Word relationships

coupling: A coupling typically connects two shafts end-to-end to transmit power, whereas a linkage is a network of links designed to transform motion paths.

isolation: Isolation refers to keeping components separate and disconnected, preventing any transfer of motion or force.

Commonly confused with

joint: A joint is the connection point between two links, whereas a linkage is the entire assembly of links and joints working together.

Word family

link (verb): To connect two or more things.
link (noun): A single ring of a chain or a single rigid member in a linkage.

Collocations

four-bar linkage
mechanical linkage
steering linkage
wiper linkage

Example sentences

"The four-bar linkage is one of the most common mechanisms used in engineering to guide paths and generate complex motions." A mechanical design textbook
"If the gear shift linkage becomes loose, you will find it difficult to engage the correct gear." An automotive repair guide

Memory hook

Think of a chain 'link' multiplied into a whole system. A 'linkage' is a collection of links working together to guide motion. Linkage is a system of links.

When not to use

Do not use linkage to describe a single, simple connection like a rope or a solid bar; it refers to a system of multiple connected parts designed to guide motion.

Fun facts

The mechanical linkage on a steam locomotive's wheels (the Walschaerts valve gear) is a masterpiece of 19th-century design, allowing the train to go in reverse by changing the timing of the steam valves.
The human knee is not a simple hinge; its ligaments act as a complex four-bar linkage that guides the rolling and gliding motion of the joint.

Related words

mechanism, actuator, gear

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