Kinematic pair

A kinematic pair is the general name for two rigid bodies that can move with respect to each other via a mechanical constraint (joint) between the two bodies. In kinematics, one classifies the kinematic pairs in two groups:

• Lower pairs: the constraints is of the surface type. The following joint types exist: revolute joint ("pin", "hinge"), prismatic joint ("slider"), cylindrical joint, screw joint, planar joint, and spherical joint ("ball and socket").
• Higher pairs: the constraint is of the curve or point type. For example: cams or gears.

Kinematic pairs are the building blocks of most kinematic chains and mechanical linkages, e.g., gimbals, robots, car suspensions.

See also

• Degrees of freedom
• Kinematics