| 摘要 |
The invention relates to an actuator for axial displacement of an object, the actuator (1) comprises an actuator piston (4) comprising and an actuator piston rod (7), wherein the actuator piston (4) is displaceable in the axial direction, and a hydraulic circuit (20) comprising a liquid filled chamber (21), the first end (8) of the actuator piston rod (7) being arranged to be displaced in the axial direction within said liquid filled chamber (21),wherein an axially extending recess (22) mouth in said liquid filled chamber (21) and is arranged to receive the first end (8) of the actuator piston rod (7). The actuator is characterized in that the actuator piston rod (7) in the area of a first end (8)presents a cylindrical envelope surface (24), and in that the recess (22) presents a cylindrical inner surface (25) having matching shape, wherein the actuator comprises a passage extending between the recess (22) and the liquid filled chamber (21) when the cylindrical envelope surface (24) and the cylindrical inner surface (25) are located in overlapping configuration, wherein the passage presents at a braking overlap section a cross section area (A) that decrease as a function of increasing overlap between the cylindrical envelope surface (24) and the cylindrical inner surface (25). |
