Magnetic Seal System for Belt Conveyor Rollers

The present invention relates to a magnetic seal system for belt conveyor rollers and, more particularly, relates to a seal system formed by axially disposed magnetic radial rings forming a labyrinth seal arranged before the ball bearings of belt conveyor rollers for retaining particles of naturally magnetic pollutant dust, thereby avoiding its propagation into the ball bearings.

For many years an effective form of preventing the entry of naturally magnetic material dust (i.e. dust from iron ore) into the ball bearings of belt conveyor rollers has been sought. Such contaminating material, entering the bearing and polluting them, consequently significantly reduces their useful life by wearing or locking. However, because of the great number of rollers in a conveyor system, the seals could not increase friction without significant inpact on the power required to drive the conveyor. Therefore, rubbing seals were inappropriate, and labyrinth seals, by themselves, tended to permit the pollutants to enter.

The present invention has an object to solve this problem by providing a magnetic seal system, which comprises basically a radial labyrinth defining a magnetic portion able to prevent naturally magnetic dust particles from entering into the ball bearings.

Notwithstanding that the present invention is described as applicable to belt conveyor rollers, the same will be applicable for other types of mechanical seals for bearings wherein a blocking of naturally magnetic particles may be necessary, such as in applications with bearing seals in apparatus for handling ore of iron and steel.

The FIGURE is an elevational cross-sectional view of the labyrinth seal system of the present invention.

Referring to the FIGURE, a magnetic seal system for the roller bearings 11 of a belt conveyor idler or roller 12, 13 is shown. As therein seen, the system comprises a radial labyrinth 10 formed by a pair of radial rings of magnetic material 15', 15" axially separated from one another, and as is well known in the art of labyrinth seals, mounted for relative rotation with respect to each other.

The rings 15' and 15" are disposed between the roller bearing 11 and the ambient conditions or conditions outside the roller to prevent dust particles from entering the bearing 11.

Thus, naturally magnetic particles coming into the vicinity of the rings 15', 15" will be attracted to and held thereby without entering the bearing. As is clearly noted in the FIGURE, the magnetic rings form a relatively restrictive path without any rotational rubbing, and have an axial thickness to increase the magnetic attraction area in the vicinity of the most restrictive postion of the path, whereby the magnetic dust particles are attracted to the rings to provide an effective seal to such particles without increasing any rotational resistance or defining any wear parts.