摘要 |
In apparatus of the type having a shaft which moves axially or is rotated, a rotary seal on the shaft for eliminating the breakaway friction between the shaft and its mount. The seal includes an inner sleeve surrounding the shaft and rotatable thereon, the sleeve having one or more seals on the inner surface thereof and in engagement with the shaft. The inner sleeve is supported at its ends on a pair of bearings which mount the shaft for movement. An outer sleeve fixed relative to a reference surrounds the inner sleeve and is received within a tubular member forming part of a fixed support. A power device coupled through a driver spur gear and a driven spur gear rotates the inner sleeve relative to the shaft and the outer sleeve as the shaft moves in a particular direction, such as axially or rotationally. The inner sleeve thereby eliminates the axial component of breakaway friction between the inner sleeve and the shaft. The inner sleeve can rotate in one direction or back and forth in opposite directions.
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