Revolute joint

[1] 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, mechanisms, and other uni-axial rotation devices.

It enforces a cylindrical contact area, which makes it a lower kinematic pair, also called a full joint.