Surgical instrument (100) comprising: a housing (110)； an endoscopic part (140) extending distally from the housing (110) and defining a first longitudinal axis (A-A)； a drive gearwheel (200) arranged at least partially inside the housing (110), the drive gearwheel (200) being able to rotate about a drive gearwheel shaft (CC) extending therethrough and being able to move selectively along the axis (CC) of the drive gear wheel between a first position, a second position and a third position； a drive motor (210) arranged in mechanical cooperation with the drive gear (200) and which is configured to rotate the drive gear (200)； a displacement motor (220) arranged in mechanical cooperation with the drive sprocket (200) and which is configured to move the drive sprocket (200) along the drive sprocket (CC) axis between the first position, second position and third position； a rod portion (1500) selectively connectable to a distal end of the endoscopic part； an end effector (160, 1600) selectively connectable to a distal end of the stem part, including the end effector (160, 1600) a first jaw element and a second jaw element, and the end effector (160) defining a second longitudinal axis (BB)； a toothed crown (230) arranged at least partially inside the housing (110) and which is arranged in mechanical cooperation with the end effector (160, 1600), causing the rotation of the toothed crown (230) the rotation of at least one part of the end effector (160, 1600) around the first longitudinal axis； an actuator sprocket (300) arranged at least partially inside the housing (110) and which is arranged in mechanical cooperation with the end effector (160, 1600), causing the rotation of the actuator sprocket (300) to move at least one jaw element towards the other jaw element； and an articulation gearwheel (240) arranged at least partially inside the housing (110) and which is arranged in mechanical cooperation with the end effector (160)； wherein the drive gear (200) is mechanica
