US Patent 11624255 Rotating control device with debris-excluding barrier

A rotating control device can include a bearing housing, an inner mandrel rotatably supported in the bearing housing, and a barrier having upper and lower portions, the upper portion being secured against rotation relative to the inner mandrel, the lower portion being secured against rotation relative to the bearing housing, the lower portion including annular recesses, the recesses being progressively deeper in a radially outward direction. Another barrier can include upper and lower portions, the lower portion including multiple annular walls, an upper surface of each wall being inclined downward in a radially outward direction. Another barrier can include upper and lower portions, the upper and lower portions having annular walls, the upper portion walls being interdigitated with the lower portion walls, and the upper and lower portion walls being circumferentially discontinuous, whereby gaps are formed between circumferential ends of the upper and lower portion walls.