Blohm + Voss Ag

Howaldtswerke-deutsche Werft Aktiengesellschaft Hamburg Und Kiel

Blohm Voss Holding Ag

Gunter E Pietsch

Ernst-Peter Von Bergen

Gerhard H Walter

Holger Hillig

Bodo Voss

Gunter Mewes

Gert Schrader

A system to adjust to the changing draft of ocean-going ships on the aft seal system equipped with several outwardly-directed gaskets and one inwardly-directed gasket, in which, between each two outwardly-directed gaskets a ring-shaped chamber is reserved, to which a feed line for compressed air is connected. Integrated into the feed line is a pressure control mechanism and a discharge channel which can periodically empty into the interior of the ship (bilge), whereby the pressure in the ring-shaped chamber is always maintained slightly below the outside water pressure. The system is characterized by the fact that an electronic draft measurement system is located on the ship's hull to supply electric signals which correspond to the current draft, which signals actuate the pressure control mechanism. In addition, for the lubrication system, there are two pressure control mechanisms pressurized by compressed air, and which are also actuated by the signals of the draft measurement system, whereby these pressure control mechanisms are each connected to the gas cushion of their own externally airtight containers which are pressurized with lubricant and in which a specified level is maintained, whereby the one container empties into a ring-shaped chamber between the inwardly-directed gasket and the outwardly-directed gasket, and the other container empties into the lubricant chamber.

Stern tube seal with a pressure control system to adjust to the changing

A safety device on an aft seal system equipped with at least two gaskets for a ship's propeller shaft, which propeller shaft is sealed with respect to the outside water and with respect to a lubricant chamber, and on which a ring-shaped chamber is reserved between each two gaskets, to which chamber are connected a feed line for compressed air and a discharge channel which can be emptied by means of a solenoid valve which opens and closes periodically. The pressure in the ring-shaped chamber is kept always slightly lower than the respective outside water pressure and the lubricant pressure by means of a pressure regulation mechanism. In the feed line to the ring-shaped chamber, downstream of the pressure regulation mechanism there is a solenoid valve, and downstream of that there is an airtight container with a float switch, whereby when the container is full of fluid due to a clogging of the discharge channel, the solenoid valve closes and thereby protects the pressure regulation mechanism and the other units against flooding.

Safety device for seal systems for propeller shafts on ships

A seal arrangement for controlling any large bearing clearance in the vicinity of a propeller shaft, such as for a propeller drive system for ships with two concentric propeller shafts rotating in opposite directions, has a housing ring for supporting the sealing lips and a supporting ring for supporting the housing ring and defining a clearance therebetween. This clearance can be sealed, and maintained by means of elastic ring walls disposed between and interconnecting the housing to the supporting ring, so that compensation can be achieved for changes in the clearance during rotation of the propeller shaft.

Seal arrangement for propeller shafts of ships

A seal arrangement for controlling any large bearing clearance in the vicinity of a propeller shaft, such as for a propeller drive system for ships with two concentric propeller shafts rotating in opposite directions. The seal arrangement has a housing ring for supporting the sealing lips and a supporting ring for supporting the housing ring and defining a clearance therebetween. This clearance can be sealed and maintained by using elastic ring walls disposed between and interconnecting the housing to the supporting ring, so that compensation can be achieved for changes in the clearance during rotation of the propeller shaft.

This invention relates to lip seals for shafts, whose lip bodies consist of rubber elastic material, and is mounted on the reverse side on an essentially radial surface of a back-up ring which is integral with the housing. When the pressure of the medium to be sealed out increases, dangerous overloads occur on the lip edge, in spite of the roller diaphragm-like deformation of the lip body. According to the invention, these overloads are reduced by the introduction of a trough in the supporting back-up ring in the zone of the lip body near the clamp, into which the lip body is deformed and thus the pressure on the edge of the lip is reduced (FIG. 1 ).

Lip seal to seal a shaft, in particular a ship's propeller shaft

A ship, in particular a deep-draft vessel configured for travel on the oceans or great lakes, can have a hull with two concentrically rotating propeller shafts passing through the hull, and rotate in opposite directions to one another. The ship will generally have seals between the propeller shafts, and between the propeller shafts and the hull. In general, it is necessary to lubricate and cool the sealing surfaces of the individual seals, so that the useful life of the individual seals is prolonged, and the risk of failure of the seals is reduced. For the effective lubrication of highly-stressed seals of propeller drive systems for ships with two concentric propellers rotating in opposite directions, a forced feed lubrication system with circulating lubricating oil has been found to be advantageous.

Ship, in particular deep draft vessel having concentric, contra-rotating

A seal arrangement for controlling any large bearing clearance in the vicinity of a propeller shaft, such as for a propeller drive system for ships with two concentric propeller shafts rotating in opposite directions, has a housing ring for supporting the sealing lips and a supporting ring for supporting the housing ring and defining a clearance therebetween. This clearance can be sealed, and maintained by using elastic ring walls disposed between and interconnecting the housing to the supporting ring, so that compensation can be achieved for changes in the clearance during rotation of the propeller shaft.

The invention employs the principle of the prior art for cooling a heated body by means of so-called heat pipes, with seal devices for rotating shafts, in particular for a ship's propeller shaft. According to this principle, an externally closed chamber extending in the longitudinal direction and filled with a liquid working fluid extends on one end into the body to be cooled, and on the other end into a cold medium, whereby a constant circulation takes place, so that the work fluid is evaporated in the hot portion of the chamber, the vapor flows into the cold portion of the chamber, condenses there, and the condensate is returned to the hot portion by way of a capillary structure (FIG. 1 ).

Seal device for rotating shafts, in particular stern tube seal for

A sealing apparatus for rotating shafts, in particular a stern tube seal for a propeller shaft of a ship with or without shaft bushings, with aligned gaskets resting on the shaft and located in a stationary support system, preferably of an axial face seal, and with a backup seal located in the support system, which is designed as a gland seal with soft packings, and a gland which can be moved in the axial direction in a guide body connected to the support system, whereby between the guide body and the gland there is a cavity system, into which, when there is a failure of the main seal, a hydraulic or pneumatic pressure medium can be introduced, which activates the backup seal, is characterized by the fact that the cavity system consists of a number of individual piston-cylinder units uniformly distributed over a circle which is concentric with the shaft axis, corresponding to each of which there is a branch current of the hydraulic or pneumatic pressure medium.

Sealing apparatus for rotating shafts, in particular stern tube seal for

A seal arrangement for rotating shafts, in particular a propeller shaft of a ship which is in contact with water containing impurities, is designed to provide a filter portion substantially adjacent the outermost seal to thereby filter dirt particles out of the water and keep the dirt particles out of the vicinity of the seal. Such a filter can be made from a sintered material and can essentially be designed to fit the existing space available along the propeller shaft.

Sealing arrangement for rotating propeller shafts of ships

Sealing device for rotating shafts, in particular stern tube seal for the propeller shafts of a ship, with a main seal and a backup seal, in which the main seal is designed as a rotating mechanical seal or as a lip seal, and the backup seal is designed as a gland seal, and the activation of the latter takes place by means of an expandable body, which can be pressurized with a hydraulic or pneumatic pressure medium, preferably as a function of the pressure of the medium to be sealed out.

A lubrication system for a rotatable propeller shaft of a ship. The system includes a seal for sealing lubricant adjacent the shaft and at least one annular chamber defining a hose-shaped inflatable body. A ring line supplies a fluid heat transfer medium, such as air, to the at least one annular chamber. The heat transfer medium is heated by a heat source. The heat transfer medium may also act as a pressure medium to inflate the inflatable body. The heat transfer medium can be circulated so that when the propeller shaft is stationary in an extremely cold liquid medium, such as icy sea water, the inflatable body is inflated by the heat transfer medium so that the inflatable body expands to within a major portion of the at least one annular chamber while, simultaneously, heating lubricant in the remaining portion of the annular chamber. Such heating causes the lubricant viscosity to approximately equal the viscosity of the lubricant when the propeller shaft rotates and the lubricant is not heated. During rotation of the propeller shaft, the inflatable body is deflated out of the annular chamber.

Sealing device for a rotating shaft of a ship propeller shaft

A seal assembly for rotating shafts particularly for sterntube seals for ps comprises two slide rings mounted in a receiving ring and pressed against a counter-ring by means of the surrounding sea-water. Between the slide rings an annular space is formed into which a liquid medium is let. The outer slide ring being a hydrostatic seal is lifted by the liquid medium in the annular space against the force of a spring in the receiving ring so that a small amount of the liquid medium leaks out to lubricate the slide rings and to prevent entering of abrasive particles. The inner slide ring is a hydrodynamic seal and is urged into contact with the counter-ring by the hydrostatic head of the sea-water surrounding the seal assembly. The receiving ring is guided in the housing or on the shaft with some clearance so that the faces of the slide rings can maintain a position parallel to the counter-ring.

Seal assembly for rotating shafts

A shaft sealing assembly containing a liquid lubricant uses an arrangement hich can accommodate shaft-eccentricities and vibratory movements which cause radial deflections of the shaft, without impairing the efficiency of sealing of the assembly. The assembly is of a type using a housing in which two flexible sealing rings are spaced apart from each other and mounted to be stationary on the shaft, at least one sealing ring being supported by a mounting ring. The mounting ring is capable of radially being displaced within the housing, when there is shaft-eccentricity, or when radial vibratory movements of the shaft occur. The mounting ring is nonrotatably supported from the inside of the housing by a resilient annular wall made of a sealing material. The arrangement comprises at least one inner annular chamber containing the liquid lubricant, and at least one outer annular chamber disposed radially outside the mounting ring, the two annular chambers being provided with a connecting fluid passage. Rotation of the shaft causes the lubricant from the inner chamber to be guided by deflectors into the outer chamber via the fluid passage. The lubricant is cooled in the outer chamber and led back into the inner chamber. The shaft sealing assembly is particularly useful as an aft-stern tube seal of a vessel, providing seal-safety and long seal-life.

Shaft sealing assembly

A stern tube bearing for vessels is sealed off in a leakproof aft seal asbly which comprises at least one annular chamber between axially spaced sealing elements. The annular chamber is filled with a liquid for lubricating the sealing elements. The liquid is circulated in a circulation system through a separating tank. The head of the circulated liquid is lower than the head of a lubricant in the stern tube bearing which again is lower than the lowest possible head of the sea-water surrounding the aft seal assembly. Any sea-water or dirt entering into the annular chamber will be removed out of it by the circulated liquid and separated from it in the separating tank which can be provided with devices for supervising the circulation system. A forward seal assembly of the stern tube bearing may be included in the circulation system. The connecting pipes run in such a way that in case of any fault or interruption in the circulation system the annular chambers cannot become empty so that the sealing elements remain lubricated.

Growing community of inventors

Hamburg, Georgia

Gunter E Pietsch