revolute joint

A joint that rotates, like an elbow or knee. It allows rotational movement around an axis.

A revolute joint is a mechanical connection that allows rotational movement around a fixed axis—similar to a hinge or pivot.

Common Examples

1. Elbow - rotates your forearm up and down
2. Knee - bends your leg forward and back
3. Door hinge - swings open and closed
4. Robot arm segment - rotates around its axis

Key Characteristics

How It Works

The joint has:

1. A pivot point (axis of rotation)
2. Two connected links that rotate relative to each other
3. Limited rotation range (joint limits)

    Link 2

      |

      |---→ rotates around this axis

      |

    Link 1

In Robotics

Robot arms use multiple revolute joints in sequence:

1. Each joint adds one degree of freedom
2. A 6-joint arm can position and orient its end-effector (gripper) in 3D space
3. More joints = greater flexibility and reach

Related Term

Prismatic joint (the opposite) - allows sliding motion along an axis instead of rotation.