Hydraulic piston rod seal

In a hydraulic system, a hydraulic seal for sealing between a piston rod member and a surrounding cylinder member, one of said members having an annular gland therein with a cylindrical gland surface formed therein and spaced from a cylindrical mating surface on said other member, comprising:

• (a) a continuous nondeformable bearing ring disposed in the gland having a first cylindrical bearing ring surface for contact with said cylindrical mating surface on said other member and having a second cylindrical surface spaced axially from said first cylindrical bearing ring surface facing the cylindrical gland surface, said bearing ring also having a conical end surface extending from said first cylindrical bearing ring surface;
• (b) a continuous nondeformable backup seal ring disposed in the gland having a cylindrical surface for contact with the cylindrical mating surface on said other member and having a conical end surface which is partially exposed and partially mating with the conical end surface of said bearing ring, said backup seal ring substantially extending from the cylindrical gland surface to the cylindrical mating surface on said other member;
• and
• (c) a continuous compressible rubber ring in the gland on the side of said bearing ring opposite the cylindrical mating surface on said other member, said ring contacting said bearing ring, said partially exposed surface of said seal ring and the cylindrical gland surface at the annular gland.

In a hydraulic apparatus having a barrel and a piston rod reciprocally movable therein, apparatus for providing a hydraulic seal between the piston and the barrel, comprising:

• (a) an annular retaining plug, the outer periphery of said plug dimensioned to fit concentrically within the barrel, the inner periphery of said plug dimensioned to mate with the piston rod reciprocally movable therein, said plug having first and second glands formed therein, said first gland opening outwardly toward the barrel and said second gland opening inwardly toward the piston rod;
• (b) an O-ring disposed in said first gland for providing a static seal between the barrel and said plug;
• (c) a relatively thin nondeformable bearing ring disposed in said second gland, said ring having a first cylindrical surface for contact with the rod and a second cylindrical surface facing away from the rod and having a conical rearward facing end surface;
• (d) a continuous nondeformable backup seal ring disposed in said second gland and having a third cylindrical surface for contact with the rod and having a forward facing conical end surface which is partially exposed and partially mating with the rearward facing conical end surface of said bearing ring;
• and
• (e) a continuous compressive resilient ring in said gland on the side of said bearing ring opposite said second cylindrical structure contacting the bearing ring and the partially exposed surface of said seal ring.

In a hydraulic apparatus having a cylindrical barrel and a piston rod reciprocally movable therein, the piston rod having an annular gland formed on the surface thereof, said gland having a bottom wall confronting the barrel, an apparatus for providing a hydraulic seal between the piston rod and the barrel comprising:

• a relatively thin non-deformable continuous bearing ring disposed in said gland in contact with the inside surface of said barrel, said bearing ring having a first cylindrical surface for contact with the inside surface of said barrel and having a second surface facing away from said barrel and having a conical rearward facing end surface diverging outwardly from the surface of said barrel;
• continuous backup seal ring in contact with the inside surface of the barrel and having a forward facing conical end surface mating with a rearward facing conical end surface of said bearing ring;
• and
• continuous compressible resilient ring in said gland on the side of said bearing ring opposite the barrel contacting the bearing ring, the seal ring and the gland bottom wall whereby pressure on said resilient ring transmits pressure to said bearing ring and backup seal ring to engage said rings against said barrel.