Hydraulic cylinder buffer seal backup ring

Abstract

A seal assembly for a hydraulic cylinder piston rod of a hydraulic cylinder includes an annular buffer seal and an annular backup ring. A first axial pressure side of the annular buffer ring faces a rod end chamber of the hydraulic cylinder and fits adjacent a first axial side surface of an annular groove defined in a rod end of the hydraulic cylinder through which the piston rod passes, and a second axial seal side opposite from the first axial pressure side includes a radially outer annular seal surface and a radially inner annular seal surface, wherein the radially outer annular seal surface is spaced farther from the first axial pressure side of the annular buffer seal than the radially inner annular seal surface of the buffer seal such that an annular notch is formed around an inner diameter of the annular buffer seal on the second axial seal side of the annular buffer seal. The annular backup ring includes a radially extending leg portion that extends along substantially an entire radial extent of the radially outer annular seal surface of the annular buffer seal, and an axially extending leg portion that extends axially into the annular notch formed around the inner diameter of the annular buffer seal on the second axial seal side of the annular buffer seal.