HYDRAULIC ACTUATOR ASSEMBLY FOR A POWER PLANT

A hydraulic actuator assembly for a power plant which has a hydraulic oil storage unit to supply and retrieve hydraulic oil, and operates a valve to selectively supply and stop steam and fluid includes: a cylinder to or from which the hydraulic oil is supplied or discharged; a piston coming into contact with the inner surface of the cylinder having a piston head reciprocating in the cylinder by the supply and discharge of the hydraulic oil to selectively form a first region and a second region; an air discharge valve disposed on the piston head to selectively discharge the hydraulic oil and air from any one of the first and second regions to the other; and a lubricant storage portion on the center of an upper portion of the piston head from an outer circumference to accommodate a lubricant, and then supply it between the piston head and the inner surface of the cylinder. Since the lubricant receiving portion to accommodate the lubricant is formed along the outer circumference of the upper portion of the piston head, the lubricant is supplied between the piston head and the cylinder when the piston reciprocates, thereby preventing the piston head and the cylinder from being worn and thus improving the reliability of the product.