End face seal assemblies

Abstract

An improved rotary end face mechanical seal assembly particularly adapted for intermittent use in severe service environments. The seal comprises at least one relatively stiff primary sealing ring having an axially facing, radially directed end face portion, at least a part of which, in use, engates an oppositely directed member to form a primary seal band area. The primary seal ring includes an at least partially outwardly directed seat for receiving a portion of a secondary sealing and driving member which is made from an elastomeric material, which engages the seat so as to form a secondary seal, to transmit driving torque to said primary seal, and to prevent relative rotation between the primary seal ring and the secondary sealing and driving member. The secondary member also transmits an axial end load to the primary seal face to achieve the primary seal. The primary seal ring contains means forming a lubricant reservoir, so that lubricant may be retained in the area of the primary sealing surface even when the apparatus containing the seals is not in use, and so that, upon starting up, the lubricant will be supplied immediately to the seal faces lying immediately adjacent the seal band area. In a preferred form, the seal assemblies are formed from substantially identical pairs of seal parts, arranged in a mirror image relation.