1. Field of the Invention
The present invention relates to an eddy current coupling or a dynamoelectric machine, and more particularly to a new and improved slip ring assembly for such a device. Eddy current couplings and dynamoelectric machines of the type disclosed herein are well known in the art. Generally, a slip ring assembly is utilized to provide electrical energy to a rotating field coil. The electrical energy is generally supplied through a slip ring assembly which includes a pair of slip rings and a pair of brushes for energizing the coil. It is often desirable to enclose the slip rings and brushes to exclude hostile environments in order to prevent chemical or electrolytic corrosion. However, when the slip rings and brushes are enclosed, the chamber in which the slip rings and brushes are located tends to accumulate material worn off the brushes. This wear material is electrically conductive and when allowed to accumulate, will cause a short circuit and ultimate failure of the equipment. The present invention describes a new and improved slip ring assembly which overcomes problems associated with the prior art by providing a sealed slip ring assembly chamber and an impeller for directing particulate debris from the sealed chamber through a passageway means.
2. Prior Art
The Kawano et al U.S. Pat. No. 4,188,713 discloses a method of making a commutator for a small-sized electric motor. Kawano discloses gaps for cleaning out particulate debris by centrifugal force from between the commutator spaces but not from an atmospherically enclosed chamber.