Rotary actuation system for moving a door with orientable wings, in particular for vehicles, said rotary actuation system defining a rotation axis and comprising: - a stator shaft coaxial with the rotation axis and intended to be constrained so as not to rotate about the rotation axis, - an outer housing connected to the stator shaft so as to be able to rotate about the rotation axis, said housing having a cylindrical outer wall coaxial with the rotation axis, - an annular piston of a fluid-dynamic actuator received in a pressure chamber and able to translate parallel to the rotation axis, - a tubular rotor of a screw transmission received in the pressure chamber and connected with the piston so as to translate together with the piston parallel to the rotation axis, wherein the stator shaft, through one or more first rolling members, engages a helical rolling track formed on the rotor, so that a translation of the rotor relative to the stator shaft causes a simultaneous rotation of the rotor relative to the stator shaft about the rotation axis, wherein the rotor engages a linear guide of the housing, so that the rotor can translate relative to the housing parallel to the rotation axis and the housing rotates together with the rotor relative to the stator shaft about the rotation axis, - wherein the fluid-dynamic actuator is a double-acting actuator and the pressure chamber is divided by the piston into a first pressure chamber and a second pressure chamber arranged on opposite sides of the piston characterized in that: - said rotor engages said linear guide through one or more second rolling members, - the pressure chamber is an annular pressure chamber formed between the stator shaft and the outer wall, said piston being in sealed sliding contact with the stator shaft and with the outer wall - the stator shaft directly defines a part of both the first and second pressure chambers (9A, 9B), the rotor, the linear guide and the first and second rolling members (12, 14) are received inside the annular pressure chamber. - a stator shaft coaxial with the rotation axis and intended to be constrained so as not to rotate about the rotation axis, - an outer housing connected to the stator shaft so as to be able to rotate about the rotation axis, said housing having a cylindrical outer wall coaxial with the rotation axis, - an annular piston of a fluid-dynamic actuator received in a pressure chamber and able to translate parallel to the rotation axis, - a tubular rotor of a screw transmission received in the pressure chamber and connected with the piston so as to translate together with the piston parallel to the rotation axis, wherein the stator shaft, through one or more first rolling members, engages a helical rolling track formed on the rotor, so that a translation of the rotor relative to the stator shaft causes a simultaneous rotation of the rotor relative to the stator shaft about the rotation axis, - wherein the fluid-dynamic actuator is a double-acting actuator and the pressure chamber is divided by the piston into a first pressure chamber and a second pressure chamber arranged on opposite sides of the piston - said rotor engages said linear guide through one or more second rolling members, - the pressure chamber is an annular pressure chamber formed between the stator shaft and the outer wall, said piston being in sealed sliding contact with the stator shaft and with the outer wall - the stator shaft directly defines a part of both the first and second pressure chambers (9A, 9B), the rotor, the linear guide and the first and second rolling members (12, 14) are received inside the annular pressure chamber.