Protected seal assembly and protective filter unit therefor

摘要

A protective filter unit for use with a fluid seal assembly. The filter unit includes a screen positioning unit and a filter screen extending inwardly of portions of the positioning unit and terminating in an inner screen edge spaced just apart by a working clearance from a shaft forming a part of the sealed mechanism. The filter is associated in use with a seal having a seal casing which may be aligned with the screen positioning unit of the filter, and an elastomeric seal body having portions defining a seal band which engages the sealed shaft and another portion bonded to the seal casing. Preferably the screen positioning unit includes inner and outer support rings held apart by spacers, and the support rings, the spacers, and the screen are all made from plastic materials.