Mechanical movement with rotary resonator, which is isochronous and positionally insensitive

A mechanical horological movement comprising at least one energy storage means designed to drive a gear train of which an output mobile component is designed to pivot about a drive axis and comprising a rotary resonator which comprises at least one central mobile component designed to pivot about a central axis and comprising an input mobile component designed to collaborate with the said output mobile component, wherein the said rotary resonator comprises at least one inertial element designed to pivot with respect to the central mobile component about a secondary axis perpendicular to the said central axis and secant therewith, and returned towards a rest position, relative with respect to the said central mobile component, by at least one elastic return element, and further wherein the said secondary axis passes through the centre of mass of the said inertial element associated with it.