# What is Kinematic Link? Definition, Types, Diagram

By BYJU'S Exam Prep

Updated on: September 25th, 2023

Kinematic Link is any part of a machine that moves relative to another part. Before we get into the specifics of the kinematic link, let’s look at the link. A mechanical linkage is a collection of systems that regulate forces and movement. Geometry is used to study the movement of a body or link so that the connection is considered rigid. Joints are the connections between links modeled to provide optimal movements, such as pure rotation or sliding. A kinematic chain is a linkage representing a network of rigid links and ideal joints.

Open chains, closed chains, or a combination of open and closed chains can be used to build linkages. A joint connects each link in a chain to one or more other links. Thus, a kinematic chain can be represented as a linkage graph, in which the links are paths, and the joints are vertices. A Kinematic link can be made up of several rigidly fastened parts and does not move relative to one another.

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## What is a Kinematic Link?

A kinematic link, element, or link is a resistive body part of the machine that connects other elements that move relative to it. In a reciprocating steam engine, for example, the piston, piston rod, and crosshead are one link; the connecting rod with big and small end bearings is a second link; the crank, crankshaft, and flywheel are the third link; and the cylinder, engine frame, and main bearings are the fourth link.

“A kinematic link or element is defined as the part of a machine that has a relative motion with regard to another part of the same machine.”

A link or element must not be rigid, but it must be resistant. A body is said to be resistant if it can transmit the necessary forces with negligible distortion. The kinematic link is a vital part of the GATE exam. As a result, a link should have the following two characteristics:

• It should be capable of relative motion.
• It must be a resistant body.

A kinematic link is a machine part or assemblage of parts moving about other machine elements. As an example, consider a piston in an engine. The piston moves about other engine components, such as the cylinder and connecting rod. There are four types of the link which are:

A rigid link is one that does not deform when conveying motion. Links, in general, have a flexible nature. They are termed rigid if they do not deform much while conveying motion.

For example, crank and connecting rod.

A flexible link is one that is partially distorted while conveying motion in such a way that the transmission of motion is not affected.

Examples, Springs, chains, Rope, Belts, etc.

A fluid link is deformed by having fluid in a closed vessel and transmitting motion via the fluid via pressure.

For example, hydraulic press and hydraulic jack.

A floating link is a link that is not connected to the frame.

A kinematic link or element is any part of a machine that moves relative to another part. A link can be made up of many elements that are tightly connected together and cannot move relative to one another. The number and end vertices of a link can also be used to classify it:

A binary joint is formed when two links are linked at the same point. As an example, A chain with two binary joints, designated B, can be seen in Figure.

A ternary joint is formed when three links are linked at a junction. It is regarded as equivalent to two binary joints since repairing any one link results in two binary joints with each of the other two connections. Ternary linkages are denoted as T in Figure.