Compounding of Concurential Rotation Movements

By the composing of the rotation movements with the concurrent instantaneous axes in a point, a rotation movement with the instantaneous axis passing through that point is obtained. The resultant instantaneous angular velocity is sum of the component angular velocity. As examples of the mechanical systems in which appear the concurrent rotation movements are: the pivot bearings of the radial-axial with balls type, the ball radial bearings and the planetary mechanisms with bevel gears which are used both as differential to automotives and as orientation mechanisms (wrist) on the industrial robots.