Drive unit for raising and lowering roll-up awnings or blinds, comprising: - an electric motor and an engagement shaft rotatable about a main axis, intended for connection to the roll-up awning or blinds; - a planetary gear placed between the electric motor and the engagement shaft, comprising an upstream reduction stage and a downstream reduction stage; - an irreversibility device placed between the upstream stage and the downstream stage suitable to transmit a rotation from upstream to downstream and to block a rotation from downstream to upstream; characterized in that said irreversibility device comprises - a driver component rotatable together with planet wheels of the upstream stage, provided with at least one pair of abutments (46a, 46b) spaced circumferentially; - a driven component engageable for rotation with the driver component and rotatable together with a sun gear of the downstream stage, provided with at least one functional surface; - a tubular container body provided with a cylindrical inner lateral surface, in which are housed the abutments (46a, 46b) of the driver component and the functional surface of the driven component, which, together with the lateral surface of the container body, define a compartment, wherein said functional surface is shaped so that the compartments have a maximum radial dimension at the centre and are tapered towards the circumferential ends; - arranged in the compartment, a pair of rolling bodies (82', 82") displaceable on the functional surface and a spacer element placed between said rolling bodies (82', 82''), to maintain the two rolling bodies (82', 82") towards the circumferential ends of the compartment; wherein, in a first operating condition in which the electric motor imposes a downstream rotation, at least one of said abutments goes in contact with one of the rolling bodies (82") and pushes it towards the centre of the compartment and the driver component engages the driven body in rotation; and wherein, in a second operating condition in which the engagement shaft tries to transmit an upstream rotation, the driven body rotates so as to wedge at least one of said rolling bodies towards the circumferential end of the compartment, blocking the relative rotation with the inner surface, avoiding the entrainment in rotation of the driver component. - an electric motor and an engagement shaft rotatable about a main axis, intended for connection to the roll-up awning or blinds; - a planetary gear placed between the electric motor and the engagement shaft, comprising an upstream reduction stage and a downstream reduction stage; - an irreversibility device placed between the upstream stage and the downstream stage suitable to transmit a rotation from upstream to downstream and to block a rotation from downstream to upstream; characterized in that said irreversibility device comprises - a driver component rotatable together with planet wheels of the upstream stage, provided with at least one pair of abutments (46a, 46b) spaced circumferentially; - a driven component engageable for rotation with the driver component and rotatable together with a sun gear of the downstream stage, provided with at least one functional surface; - a tubular container body provided with a cylindrical inner lateral surface, in which are housed the abutments (46a, 46b) of the driver component and the functional surface of the driven component, which, together with the lateral surface of the container body, define a compartment, wherein said functional surface is shaped so that the compartments have a maximum radial dimension at the centre and are tapered towards the circumferential ends; - arranged in the compartment, a pair of rolling bodies (82', 82") displaceable on the functional surface and a spacer element placed between said rolling bodies (82', 82''), to maintain the two rolling bodies (82', 82") towards the circumferential ends of the compartment;