Abstract: A circumferential film-riding seal operative in a gaseous or liquid environment about a rotating shaft is provided so that it is able to function with extended lifetime, low leakage, and a high-pressure difference thereacross. These characteristics are achieved by the employment of a segmented seal ring mounted in tandem with a floating load ring surrounding the rotating shaft. The seal ring has a bore surface thereon confronting the shaft, and the bore surface has a circumferential lift region located downstream of a circumferential bearing region. The bearing region has additional lift grooves either in the seal ring or in the shaft surface confronting the bearing region, together with feed grooves connecting the additional lift grooves, respectively, to a higher-pressure region adjacent the shaft.

Abstract: A seal system for a motor pump unit includes a primary and a plurality of backup seals mounted in series within a seal housing. The primary seal is of a hydrostatic type and each of the backup seals is of a normally closed hydrodynamic type. Each of the primary and backup seals has a secondary seal between an axially movable seal ring thereof and the fixed seal housing, and at least one of these secondary seals is a spring-loaded, split piston ring seal. Two of the backup seals are of the Rayleigh type, where the Rayleigh pockets are formed in the seal runner, and the sealing dam is formed on the axially movable seal ring. An insert is provided in the runner of one of the backup seals, which insert is formed from a relatively harder material than the material forming the sealing dam. The other Rayleigh-type backup seal has pumping grooves extending downwardly and inwardly through the runner and toward the shaft to pump liquid into the Rayleigh pockets to ensure proper seal operation.

Abstract: This invention discloses a completely different hydrodynamic gas seal configuration from both the Rayleigh bearing and other prior art. Instead of the shallow, wide, and short single pocket geometry for the Rayleigh bearing, and instead of the multiple depth grooves of the other prior art teachings, the hydrodynamic seal in this invention has a sealing face with lift pockets therein that are deep (normally in the range of about 0.010 inches to about 0.025 inches deep), narrow, long, multiple, coextensive, parallel, and single-depth. This invention incorporates the same basic hydraulic principle of generating pressure rise by the shearing gradient between the rotating shaft and stationary carbon elements, and therefore produces a force which is opposite in direction to the rubbing force generated by the ambient pressure drop across the seal. In this invention the forces are more evenly balanced across the axial face of the seal ring segments, thereby accommodating any conicity of the shaft race.

Abstract: A face seal is provided for a rotating shaft for sealing between a normally high pressure region and a normally lower pressure region, having a seal ring shaped to form a gap between the ring and a runner surface on the shaft, which gap converges in the direction of fluid flow and deliberately creates turbulent flow along the seal gap and sufficient clearance between the rotating runner and the seal ring to accommodate distortions in the seal ring which may occur over its lifetime. A servo system is coupled to the seal ring which moves the seal ring away from the runner during low pressure differences between the regions and which restores the sealing function along the seal gap when the pressure difference between the regions increases sufficiently.

Abstract: A seal structure is provided having a configuration with a very small seal gap between a relatively stationary seal member and a complementary surface on a movable (rotatable) member (such as a rotating shaft) adjacent to which the stationary seal member is mounted. The stationary seal member is movable toward and away from the movable seal member so as to vary the seal gap therebetween. The seal is effective in applications where an incompressible fluid is provided on the high pressure side of the stationary seal member so that leakage along the seal gap is of an incompressible fluid into a lower pressure region on the other side of the seal gap. A sealing dam is provided on the stationary seal member on its sealing face adjacent the low pressure end of the seal gap. A plurality of elongated pads are formed on the sealing surface of the stationary seal member on the high pressure side of the sealing dam, extending perpendicularly to the direction of leakage flow along the seal gap.

Abstract: A seal for sealing between a bidirectionally rotating shaft rotatable in the forward and reverse directions and having a sealing surface thereon located in a pressurized housing containing the shaft. A seal ring mounted in the housing for movement toward and away from the shaft sealing surface and having a high pressure side, a low pressure side, a seal face opposed to the shaft seal surface and an outer face remote from the seal face and exposed to the pressure in the housing. Resilient elements urge the seal ring toward the sealing surface of the shaft. Hydrodynamic elements in the form of a plurality of spaced recesses in the seal face of the seal ring and formed so as to produce negative hydrodynamic lift in the recess and urge the seal ring toward the sealing surface of the rotating shaft during forward rotation thereof.

Abstract: A seal for sealing between a rotating shaft and a housing comprising a seal ring formed by a plurality of circumferentially spaced segments mounted for movement toward and away from the shaft and having a high pressure side, a low pressure side, an inner circumferential face opposed to the shaft and an outer circumferential face. Resilient means urge the seal ring toward the shaft. Hydrodynamic means in the form of one or more plurality of spaced recesses in the inner circumferential face of each segment are formed so as to produce negative hydrodynamic lift in the recess and urge the seal ring segments toward the rotating shaft during normal rotation thereof. The seal segments are circumferentially spaced with the radial space between adjacent segments mated by complementary tongues and grooves formed in adjacent seal segments. The segments are in contact to form a continuous seal.

Abstract: An annular windback is provided in a housing containing a lubricant sump and a rotating shaft therein. The windback is located at one end of the sump and the shaft extends through the windback. The housing has a seal interacting between the housing and the shaft to prevent lubricant from exiting the sump and to prevent other media within the housing from entering the sump. The windback is located between the seal and the one end of the sump and has a spiral groove in the inner annular surface facing the shaft for providing a return path for lubricant carried toward the seal by shaft windage. One or more radial holes are formed in the windback at an axial location thereon between the seal and the closer end of the spiral groove to equalize the pressure at the aforesaid axial location between the windback and the shaft with the pressure in the remainder of the sump.

Abstract: A seal ring construction is provided wherein a seal ring which is formed from a material which is subject to distortion during operation. One end of the ring and portions of the two adjacent sides of the ring which are adjacent the one end of the ring are received in a recess of a stiff shroud assembly. An O-ring recess is formed in each of the sides of the shroud recess which coextend with the two adjacent sides of the ring. Sealing O-rings are positioned in the O-ring recesses and means are formed in the recesses to urge the O-rings into engagement with the sides of the seal ring and into engagement with the inner surface of the shroud recess. The urging means include an inclined surface in each O-ring recess which faces the innermost surface of the shroud recess. In addition, means are provided to take up dimensional differences in the shroud and O-ring components which occur in the manufacturing process.

Abstract: A new and improved fuel assembly is formed to minimize the amount of parasitic structural material wherein a plurality of hollow tubular members are juxtaposed to the fuel elements of the assembly. The tubular members may serve as guide tubes for control elements and are secured to a number of longitudinally spaced grid members along the fuel assembly. The grid members include means thereon engaging each of the fuel elements to laterally position the fuel elements in a predetermined array. Openings in the bottom of each hollow member serve as a shock absorber to cushion shock transmitted to the structure when the control elements are rapidly inserted in their corresponding tubular members.