A motorised drive device of an occultation or solar protection device, the motorised drive device comprising at least: - a housing, - an electric motor, - a drive wheel, the drive wheel being configured to be rotated by means of the electric motor and to be placed in contact with a first rolling surface of a rod of the occultation or solar protection device, so as to move the motorised drive device along the rod in a direction of movement, - at least one driven wheel (14a, 14b), the driven wheel (14a, 14b) being configured to rotate freely, around an axis of rotation (X14a, X14b), and to be placed in contact with a second rolling surface of the rod, so as to hold the motorised drive device with respect to the rod, and - an adjustment mechanism, the adjustment mechanism being configured to adjust a distance between the axis of rotation of the drive wheel and the axis of rotation (X14a, X14b) of the driven wheel (X14a, X14b), so as to keep the drive wheel and the driven wheel (X14a, X14b) pressed against the rod, characterized in that the adjustment mechanism comprises a rack and a pawl, and in that, in an assembled configuration of the motorised drive device, the pawl is configured to interact with the rack, so as to adjust the distance between the axis of rotation of the drive wheel and the axis of rotation (X14a, X14b) of the driven wheel (14a, 14b). the motorised drive device comprising at least: - a housing, - an electric motor, - a drive wheel, the drive wheel being configured to be rotated by means of the electric motor and to be placed in contact with a first rolling surface of a rod of the occultation or solar protection device, so as to move the motorised drive device along the rod in a direction of movement, - at least one driven wheel (14a, 14b), the driven wheel (14a, 14b) being configured to rotate freely, around an axis of rotation (X14a, X14b), and to be placed in contact with a second rolling surface of the rod, so as to hold the motorised drive device with respect to the rod, and - an adjustment mechanism, the adjustment mechanism being configured to adjust a distance between the axis of rotation of the drive wheel and the axis of rotation (X14a, X14b) of the driven wheel (X14a, X14b), so as to keep the drive wheel and the driven wheel (X14a, X14b) pressed against the rod, - a housing, - an electric motor, - a drive wheel, the drive wheel being configured to be rotated by means of the electric motor and to be placed in contact with a first rolling surface of a rod of the occultation or solar protection device, so as to move the motorised drive device along the rod in a direction of movement, - at least one driven wheel (14a, 14b), the driven wheel (14a, 14b) being configured to rotate freely, around an axis of rotation (X14a, X14b), and to be placed in contact with a second rolling surface of the rod, so as to hold the motorised drive device with respect to the rod, and - an adjustment mechanism, the adjustment mechanism being configured to adjust a distance between the axis of rotation of the drive wheel and the axis of rotation (X14a, X14b) of the driven wheel (X14a, X14b), so as to keep the drive wheel and the driven wheel (X14a, X14b) pressed against the rod, characterized in that the adjustment mechanism comprises a rack and a pawl, and in that, in an assembled configuration of the motorised drive device, the pawl is configured to interact with the rack, so as to adjust the distance between the axis of rotation of the drive wheel and the axis of rotation (X14a, X14b) of the driven wheel (14a, 14b).