The present invention relates to a drive device (100) of a
brake caliper (200), comprising a
recirculating ball screw-nut
assembly within a cylinder chamber (140) in a caliper body (145), wherein the
recirculating ball screw-nut
assembly comprises a threaded shaft (150) and a nut (160) screwed externally onto the threaded shaft (150), with external teeth (165) of the nut screw,wherein the threaded shaft (150) and the nut screw (160) extend in the direction of a drive axis (170) coaxial to the threaded shaft (150), and wherein the threaded shaft (150) extends in a direction of extension from a front end thereof to a rear end thereof to a thrust plate (180),in which an axial
retaining ring (110) of the nut screw (160) is interposed between the external teeth (165) and the thrust plate (180) and held in position with the use of at least one fixing screw (120) comprising at least one respective tip (125),in which the axial
retaining ring (110) has an inclined surface (111) on which a tapered side (121) of at least one respective tip (125) of at least one fixing screw (120) interferes.