physics

Revolute joint

Revolute joint is a physics topic covered in the lgStudy science library. This page brings together a partial reference excerpt, illustrations, worked examples, real-world applications and a short study plan, so you can understand Revolute joint rather than just read about it. In short: A revolute joint (also called pin joint or hinge joint) is a one-degree-of-freedom kinematic pair used frequently in mechanisms and machines. The joint constrains the motion of two bodies to pure rotation along a common axis.

Key takeaways

Revolute joint belongs to physics; place it in that map before memorising details.
Learn the definition first, then one example that makes the definition concrete.
Connect Revolute joint to a quantity you can measure, compute or draw — that is where exam questions come from.
Reproduce the core statement of Revolute joint from memory before moving on to harder problems.

Reference excerpt

A revolute joint (also called pin joint or hinge joint) is a one-degree-of-freedom kinematic pair used frequently in mechanisms and machines. The joint constrains the motion of two bodies to pure rotation along a common axis. The joint does not allow translation, or sliding linear motion, a constraint not shown in the diagram. Almost all assemblies of multiple moving bodies include revolute joints in their designs. Revolute joints are used in numerous applications such as door hinges and other uni-axial rotation devices. A revolute joint is usually made by a pin or knuckle joint, through a rotary bearing. It enforces a cylindrical contact area, which makes it a lower kinematic pair, also called a full joint. However, If there is any clearance between the pin and hole (as there must be for motion), so-called surface contact in the pin joint actually becomes line contact. The contact between the inner and outer cylindrical surfaces is usually assumed to be frictionless. But some use simplified models assume linear viscous damping in the form T = B ω {\displaystyle T=B\,\omega } , where T is the friction torque, ω is the relative angular velocity, and B is the friction constant. Some more complex models take stiction and the Stribeck effect into consideration.

Illustrations

Worked examples

Example 1 — a first encounter with Revolute joint

Start with the simplest possible case. Write down what Revolute joint claims or describes in one sentence, then invent the smallest concrete situation in which that sentence is true. In physics, the smallest case is usually a single object, a single equation or a single measurement. Check that every symbol or term in your sentence has a meaning in that case.

Example 2 — changing one variable

Take the situation from Example 1 and change exactly one quantity: double it, halve it, or set it to zero. Predict what should happen to Revolute joint before you calculate. Comparing your prediction with the result is the fastest way to find out whether you understand the idea or only the words.

Example 3 — an exam-style question

Typical questions about Revolute joint ask you to (a) state it precisely, (b) apply it to given data, and (c) explain a limitation. Practise writing all three answers in under five minutes; the third part is what separates a full-mark answer from an average one.

Applications of Revolute joint

In research: Revolute joint appears in physics research whenever the underlying quantities have to be modelled precisely. Papers usually cite it as a starting assumption and then explore where it breaks down.
In technology and industry: Engineering practice reuses Revolute joint in design rules, simulations and safety margins. Knowing the idea lets you read a specification sheet and understand why the numbers look the way they do.
In the classroom: Revolute joint is common in secondary-school and first-year university syllabi. It links to neighbouring topics Classical mechanics stubs, Kinematics, Rigid bodies, so understanding it makes those chapters shorter.
In everyday life: Look for Revolute joint outside the textbook — in sport, cooking, traffic, electronics or the sky above you. An example you found yourself is remembered far longer than one you were given.

Ask Teacher Smith questions about this articleOpens your AI tutor with a question about “Revolute joint” →

Affiliate

Preply — study more efficiently by working with a personal tutor. 50% off.

How to study Revolute joint in 20 minutes

Read the reference excerpt below once, without taking notes.
Close the page and write down what Revolute joint means in your own words.
Compare your version with the excerpt and mark what you missed.
Work through the three examples above with pen and paper.
Explain Revolute joint out loud to somebody else — or to Teacher Smith in the lgStudy chat.

Frequently asked questions

What is Revolute joint in simple terms?

Why does Revolute joint matter?

Because it connects several physics ideas at once: it gives you a definition you can apply, a quantity you can calculate, and a way to check whether a result is plausible.

How should I study Revolute joint?

Read the excerpt, restate it from memory, then work through the examples and applications listed on this page. The five-step study plan above takes about twenty minutes.

What does this page cover?

It gives you a compact reference excerpt plus original lgStudy explanations, examples, applications and study material on Revolute joint.