Abstract: Hydraulic wing actuator for turning movement of a spindle, especially a rudder stock (3), comprising a lower part (2) fixed to the ship hull and an upper part (1) secured to the lower part and which together define a substantially torus shaped guiding path for wings (8, 7) connected with the lower part and the rudder stock respectively, where a ball shaped hub (4) being secured to the rudder stock (3) and journalled slideably in the lower and upper parts, creating the radially inward facing, concave limitation of the guiding path, which remaining torus shaped part being formed by the upper and lower parts, at least one fixed partition wall (5) being connected with the lower part and the upper part and comprising to both sides protruding wings (8) abutting tightly to the guiding path, whereby one fluid conduit leads to each side of each fixed partition wall (5) for alternatively pressurizing or depressing the two spaces on both sides of the partition walls, and at least one carrier (6) being fixedly connected