Rotary-linear actuation assembly

A rotary-linear actuation assembly (10, 110) comprising a casing (25, 125) with which there are associated:

• an output shaft (14, 113) arranged coaxial with an actuation axis (A) in a translationally and rotationally movable manner;
• at least two actuators, of which a first actuator (11, 111) is adapted to impart a translational movement along the actuation axis (A) on the output shaft (14, 113) and a second actuator (12, 112) is adapted to impart a rotary movement around the actuation axis (A) on the output shaft (14, 113);
• and
• at least one position sensor (30, 130) adapted to detect an instant position of the output shaft (14, 113) inside the casing (25, 125);
• wherein said at least one position sensor (30, 130) is mounted in a rotationally fixed manner about the actuation axis (A) and in a translationally fixed manner along the actuation axis (A), and faces at least a portion (14b, 113a) of the output shaft (14, 113),
• wherein the at least a portion (14b, 113a) of the output shaft (14, 113) bears, on an outer surface thereof, a two-dimensional mark (31, 131) that extends over at least an angular portion around the output shaft (14, 113) and at least an axial section along an axial extension of the output shaft (14, 113),
• wherein said at least one position sensor (30, 130) includes a single stationary sensor that detects both an instant axial position and an instant angular position of the output shaft,
• wherein the stationary sensor is an optical sensor and comprises a laser source emitting a light beam (32) aligned to impinge on the at least a portion (14b, 113a) of the output shaft that bears the two-dimensional mark (31, 131), and a photodetector toward which a return beam (33) is reflected, and
• wherein the two-dimensional mark (31, 131) comprises a plurality of areas (40), and each of the areas (40) comprises invariable markers (41) defining at least one of the contour and center thereof and acting as references.