Seals with particle exclusion means

摘要

A particle exclusion assembly (10) designed to operate in an inclined position and to protect an associated sealing assembly. The assembly includes radially inner and outer relatively rotatable walls (20,22) and axially inner and outer baffles (12,16) and a rotary, controlled porosity, open-celled element (16) which substantially fills the cavity between the two walls (20,22) and the two baffles (12,16). The open-celled element (16) controls the rate of movement of particulate material and restricted annular opening (18) is provided to control ingress and egress of particulate material from the open-celled element (16).