Towards Theoretical Kinematics

Theoretical kinematics deals with the general properties of motion. In the eighteenth century in particular work on cycloids, gear wheels and the motion of a rigid body in space yielded the first results. First we discuss the roots of the instantaneous center of rotationInstantaneous center of rotation. We describe how De la HireHirePhilippe de La discovered what is nowadays called the inflexion circleInflexion circle and how Euler discovered the so-called Euler-Savary formulaEuler-Savary formula. We also discuss the appearance of the instantaneous axis of rotation in spherical kinematics and the instantaneous screw axis in space kinematics. Pieces of theoretical kinematics that later became part of a coherent whole emerged in different areas.