Stroke cushioning apparatus for hydraulic cylinders

摘要

A stroke cushioning apparatus for a hydraulic cylinder provided at rod side stroke end and/or head side stroke end. The rod side stroke end cushioning apparatus comprises a sleeve mounted on a piston rod and a cushion ring mounted on the inner face of a housing defining a passage which accommodates the sleeve when a piston assembly is moved to its rod side stroke end. The cushion ring is allowed to move slightly in an axial direction. When the piston assembly is moved towards its rod side stroke end and the sleeve enters into the passage, flow of fluid is restricted between the cushion ring and the sleeve thus effecting a cushioning action to the piston assembly. The head side stroke end cushioning apparatus comprises a plunger mounted to the piston rod and wall of a passage formed at the head end of the cylinder. The plunger is mounted to the piston rod by means of a plurality of balls with allowing slight movements of the plunger both axially and radially. When the piston assembly is moved towards its head side stroke end and the plunger enters into the passage, flow of fluid is restricted between the plunger and the wall of the passage thus effecting a cushioning action to the piston assembly.