摘要 |
An air bearing is coaxially mounted around a rotatable shaft, such as an engine crankshaft, by means of a flexible boot having walls forming a chamber therebetween. The bearing includes a pair of flexible lip seals thereon which contact the shaft at low speeds or when the shaft rotation is stopped and thereby effects sealing. The boot chamber is adapted to be pressurized by air to lift the seals out of contact with the shaft. In this manner, continuous streams of air will flow past the seals to prevent oil or contaminants from moving in a direction opposite to the air flow direction. The bellows arrangement, integral with the lip seal assemblies, enables the seal to be moved in a radially outward direction to accommodate lateral shaft movement. An alternate embodiment eliminates the lip seals and produces a dynamic seal which compensates for temperature differential affects and makes the air bearing clearance with the shaft self-compensating.
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