Labyrinth lubricant seal for belt conveyor roll

摘要

The embodiment of the invention disclosed is a conveyor roll having a cylindrical shell with integral end caps and axial sleeves extending inwardly from the end caps. The shell, end caps and sleeves are rotatably journalled about the shaft by roller bearings between the sleeves and the shaft. An internal labyrinth is provided in each sleeve between the bearing and the end of the shell, this internal labyrinth including a rotatable collar and a non-rotatable bushing carried respectively by the shell and shaft and having a series of facing cylindrical and annular surfaces providing a labyrinthine passageway of restricted cross-section extending from the bearing means to an annular outlet at the end of the shell. An external labyrinth is provided outside the end cap. This includes first and second annular flanges carried respectively by the shaft and shell and axially spaced from the annular outlet and from one another. These two flanges provide inner and outer radial passages. The outer radial passage has radial and axial dimension exceeding those of the inner radial passage whereby centrifugal force acting on a radial column of lubricant in the outer radial passage opposes leakage from the shell.