Abstract: The invention concerns a mechanism having the necessary conditions in order that the rotational motion of a body can be actuated in a decoupled and homokinetic way by motors (M1, M2, M3) installed on the same frame, by means of transmission based on homokinetic joints (CV). In particular, decoupled and constant relations are generated between the motors speeds (q1, q2, q3) and the time derivatives of the variables describing the body orientation (?1, (?2, ?3), thus maintaining the homokinetic condition of the transmission during the simultaneous movements of more motors. The invention therefore concerns new architectures of decoupled and homokinetic joints, with two or three degrees of freedom. They are characterised by uniform input-output kinetostatic relations and suitably wide working spaces.