A device for transmitting motion between the rotor of a synchronous permanent-magnet motor and the working part, having an increased free rotation angle, which comprises at least two motion transmission couplings which mutually cooperate in a kinematic series. Each coupling is constituted by at least one driving element which is eccentric with respect to the rotation axis and is rigidly coupled to a first component of the motion transmission system and by at least one driven element, which is also eccentric with respect to the rotation axis and is rigidly coupled to the component arranged kinematically after the preceding one. The angle covered by the elements of each coupling is, as a whole, less than a round angle. The intermediate components of the kinematic transmission have both a driven element and a driving element for receiving the motion from the preceding one and transmitting it to a subsequent one.