Abstract: A shaft seal has a pair of stationary, yet floating, seals which are biased into engagement with opposite sides of a mating ring carried on a rotating drive sleeve. The mating ring is maintained perpendicular to the axis of rotation and against a squaring surface of the drive sleeve. The location of a secondary seal pressure balances internal machine pressure at the primary seal at a ratio of 80:20, and provides a reverse pressure balance of greater than 100%.
Abstract: A shaft seal comprises a holder carrying a carbon seal for rotation against an end surface of a stationary seal ring, the holder being coupled to a drive sleeve secured to a shaft of the machine which extends through an end wall which mounts the seal ring. The coupling is provided by drive lugs extending from the inboard end of the drive sleeve into slots within the seal holder. A seal is provided between the drive sleeve and the seal holder and is axially movable along a travel land which is equal to the travel land of axially longer shaft seals.
Abstract: Relatively rotating face ring-type shaft seals especially useful for sealing the shaft bearings and lubricant chamber of mud motor driven downhole drill rigs, have a plurality of telescoped annular seal rings slidably mounted in an annular carrier element and riding over the radial face on a face ring to define a sealed intermediate chamber therebetween. This intermediate chamber may be filled with lubricant. Either the telescoped rings or the face rings rotate with the shaft. Biasing means, such as a plurality of springs, load end faces on the seal rings against the radial face of the face ring. Pressure transmission means, such as pistons, O-rings, or the like, mounted in either the carrier element or the face ring, are loaded by the ambient media pressure, such as drilling fluid, to maintain pressure in the intermediate chamber responsive to the pressure of the ambient media.