Abstract: A rotary mechanical face seal includes first and second seal face members, the sealing face of one seal face member being urged into engagement with the sealing face of the other seal face member, said seal face members being such that when subjected to temperature gradients due to the generation of heat at the sealing faces, the sealing faces will remain substantially parallel in spite of any thermal distortion of the seal face members.

Abstract: A rotary mechanical face seal includes first and second seal face members, the sealing face of one seal face member being urged into engagement with the sealing face of the other seal face member, said seal face members being such that when subjected to temperature gradients due to the generation of heat at the sealing faces, the sealing faces will remain substantially parallel in spite of any thermal distortion of the seal face members.

Abstract: A mechanical face seal has a first seal face member mounted in fixed rotational and radial relationship to one component and sealed with respect thereto; abutment means mounted in fixed rotational and radial relationship to a second component and sealed with respect thereto; and a second seal face member interposed between the first seal face member and the abutment means. Spring means is arranged to apply an axial load between the first and second seal face members, said second seal face member having opposed faces, one of said faces being maintained in sealing engagement with a corresponding face on the first seal face member under the axial load applied by the spring means and the other face being sealed with respect to a corresponding face on said abutment means.

Abstract: A mechanical face seal comprises a first seal face member associated in fixed relationship and sealed with respect to one component, a second seal face member associated in fixed rotational relationship and sealed with respect to a second component and a third seal face member interposed between the first and second seal face members. Springs are provided to urge the second seal face member towards the first seal face member and maintain the first, second and third seal face members in sealing engagement. The sealing faces of the first, second and third seal face members are inclined, so that the first and second seal face members impose a radial load on the third seal face member. Two such seal assemblies may be provided co-axially of one another to provide a double seal.

Abstract: In a mechanical face seal for producing a fluid tight seal between a pair of relatively rotatable components a first sealing element is associated with one of said components and is fixed axially with respect thereto; a second sealing element is associated with the other component and is movable axially with respect thereto; means is provided for sealing the second sealing element with respect to its associated component and loading it axially into sealing engagement with the first sealing element and a thrust bearing is provided between the sealing element to partially reduce the load applied thereto.

Abstract: A method of monitoring the wear of the sealing faces of a mechanical face seal comprising; positioning a probe radially of the axially moveable seal face member of the seal or a component which moves axially with the seal face member; producing a signal which is directed radially outwardly from the surface of the seal face member or component so that it may be picked up by the probe; and arranging the surface of the seal face member or component such that there is a change in signal, indicative of the wear on the sealing faces, as the seal face member moves axially with respect to the probe.

Abstract: A mechanical face seal comprises a seat associated with one of a pair of relatively rotatable components and a seal face member associated with the other component and movable axially with respect thereto. Said seal face member has a sealing face which engages an opposed face of the seat to provide a seal therebetween, and an integral secondary sealing means remote from said face. Means is provided to urge the seal face member axially into sealing engagement with the seat and the secondary sealing means radially into sealing engagement with the component associated with the seal face member.

Abstract: A seal assembly primarily for use with the stern bearing of a ship comprises inner and outer face seal elements mounted on a rubber body for rotation with the propeller shaft. Any oil from the bearing which leaks past the inner element, or sea water which leaks past the outer element, enters a void space formed by pockets in the rubber body. These pockets are separated by inclined vanes which act as a centrifugal pump to expel the leakage material through a passage in a seat for the seals. The assembly can also be used in other applications where the leakage material is corrosive or is likely to cause blockages.

Abstract: A seal for producing a liquid-tight closure between a rotary component and a partition separating two chambers, where the rotary component penetrates the partition, said seal includes a retaining means which may be secured to the partition so that it surrounds the rotary component. The retaining means locates an annular floating member, so that it is free to float radially. The annular floating member has a small clearance about the rotary component and is provided with sealing means which will close the gap between the floating member and the rotary component to form a liquid-tight closure, upon exposure to liquid, following the flooding of one of the chambers.

Abstract: A shaft seal including a sealing element and a drive ring assembly for mounting the sealing element with respect to a shaft, for rotation therewith; the drive ring assembly comprising a pair of concentric rings one mounted within the bore of the other, a plurality of circumferentially spaced radial clamping screws in screw threaded engagement with the outer ring, so that they may be tightened against the outer surface of the inner ring, the abutting surfaces of the screws and the inner ring being mutually inclined, so that tightening of the screws against the inner ring, will cause the inner ring to move axially towards a shoulder on the bore of the outer ring, so as to compress a sealing ring positioned between the shoulder and the opposed end of the inner ring, thereby causing the sealing ring to expand radially into sealing engagement with the opposed surfaces of the shaft and the outer ring, while at the same time said screws deform the inner ring into clamping engagement with the shaft.

Abstract: A mechanical face seal adapted to withstand a pressure differential across its sealing faces, includes a bellows unit of monolithic construction, comprising a plurality of corrugations, the crowns of the convolutions directed towards the high pressure side of the seal being of greater radius of curvature than the crowns of the convolutions directed towards the low pressure side of the seal.

Abstract: A rotary face seal located about a shaft and urged into seal face contact with a stationary seat formed on a housing which contains pressurized fluid. In order to overcome distortion of the seal due to the fluid pressure, which is likely to cause wear of the seal face, the seal is subjected to a radial compressive pre-stress applied between an elastomeric, e.g. rubber, strip and a support ring.

Abstract: An axially movable seal face member of a rotary mechanical face seal, for example for a ship's stern shaft, is sealed to its associated structure, and at the same time loaded axially, by the wedging action of a ring urged radially between two oppositely inclined annular surfaces on bodies associated with the member and the structure, either the ring or the surfaces or both being of resilient material. The ring could be a rubber O-ring and the surfaces could be two further O-rings. Alternatively the ring could be rigid, or the ring could be resilient but the other two surfaces rigid.

Abstract: A sealing member for sealing an axially movable face seal member to an associated component comprises an annular body of graphite or other predominantly carbon-containing material of U-shape or C-shape in cross-section formed around a supporting annular core.

Abstract: A rotary mechanical seal assembly for a shaft comprises a freely floating ring of flexible material which has inner and outer axially directed lips to bear against the surfaces of the shaft and housing, at least one of these lips being normally out of contact with its associated surface so that no wear takes place. The seal is brought into action by the application of pressure either applied from an outside source or created by leakage past an adjacent upstream face-type seal for which the seal of the invention forms an emergency back-up. There may be a detector to sense the leakage. There could be two such lip seals facing one another.

Abstract: In a stern seal and bearing assembly for the stern shaft of a ship there is an oil seal assembly at the outboard end of the bearing and a sea water seal (preferably a face seal) axially spaced from it, with a drain from the space between the two, and the oil seal assembly comprises a pair of lip seals directed towards each other with a drain from the space between them. The oil supply to the bearing can be at low pressure, for example simply the static head from a tank slightly above the level of the bearing, and the last-mentioned drain may have a swan neck above the oil level.