US20170313398A1

US20170313398A1 - Protective device for the sealing of a stern tube of propeller-driven ships

Info

Publication number: US20170313398A1
Application number: US15/523,799
Authority: US
Inventors: Johannes Goetz; Wolfgang Brandt; Nils BOETTCHER; Carlos Fangauf; Detlef Hammerschmidt; Andreas Konieczny; Fred Menig; Christian Preißler; Mathias Rusch; Marko Wrage; Lars Ziemen
Original assignee: SKF Marine GmbH; SKF AB
Current assignee: SKF Marine GmbH
Priority date: 2014-11-12
Filing date: 2015-11-12
Publication date: 2017-11-02
Also published as: DE102014223064B4; CN107108005A; WO2016075230A2; JP6840667B2; WO2016075230A3; JP2017534524A; DE102014223064A1; KR20170088831A

Abstract

A protective device for a stern tube seal of a propeller-driven vessel, wherein an intermediate space is left open between a stern tube and a propeller hub, which intermediate space is covered by a tubular protective cover concentric with the propeller hub, which protective cover is fixedly anchored to the stern tube and axially overlies the propeller hub leaving an annular gap, wherein a ring concentric with the propeller hub and U-shaped in radial section is disposed inside the protective cover in the intermediate space between the stern tube and the propeller hub, the U-opening of which ring is directed radially outward, and wherein the ring is at least partially formed of a material that has a pourable consistency at 20° C.

Description

The invention relates to a protective device for the stern tube seal of propeller-driven vessels, wherein an intermediate space is left open between the stern tube and the propeller hub, which intermediate space is covered by a tubular protective cover (rope guard) concentric with the propeller hub, which protective cover is on the one hand fixedly anchored to the stern tube and on the other hand spreads over the propeller hub leaving an annular gap, wherein a ring concentric with the propeller hub and configured U-shaped in radial section is disposed inside the protective cover in the intermediate space between stern tube and propeller hub, the U-opening of which ring is directed radially outward.
A protective device of the above-described type is known from DE 37 18 419 C2. According to this, a net guard is installed on vessels for protection of the stern tube-seal and -bearing. This net guard is usually flange-mounted directly on the drive propeller. Should nets and ropes be located in the water, they are wound up due to the U-shaped geometry of the guard and received in the U-shaped design until a maintenance, in the context of which a removing of the nets and ropes is effected.
Here the ring is disposed and dimensioned in relation to the annular gap such that ends of fishing lines, fishing nets, or similar cord-shaped structures possibly entering through the annular gap are captured by it and wound up.
Due to the large diameter of the ring in question, of the material used (aluminum bronze is usually used for this purpose), of the manufacturing method, and of the processing, relatively high costs arise that sometimes induce the operators of vessels to omit the net guard. In addition there is the high weight that complicates the handling, installation, and maintenance of the rings. Of course the omission of the net guard, i.e., of said ring, represents a great danger to the vessel propulsion.
To attach the rope guard, i.e., the ring, using screws, a hole pattern is required in the ring for flange mounting, which hole pattern varies depending on the vessel or on the respective application. Therefore depending on the application case the bores are introduced shortly before the delivery or installation of the net guard.
The object of the invention is to further develop a protective device of the above-described type for the stern tube seal of propeller-driven vessels such that the disadvantages mentioned are avoided. Accordingly an easily handleable and cost-effective solution is to be provided. Both the manufacture of the net guard and its installation should thus be able to be simplified.
The solution of this object by the invention is characterized in that the ring is at least partially comprised of a material that can have a pourable consistency at room temperature (T=20° C.). Concrete, in particular mineral casting, is preferably considered here.
Here the ring is preferably comprised of at least two ring sectors, wherein each ring sector extends over a defined circumferential angle and wherein the ring sectors are preferably connected to one another. Particularly preferably two, three, four, five, or six ring sectors are provided here that form the ring.
Here the ring sectors can be oriented relative to one another using centering elements; the centering elements are preferably formed from a complementary profiling of the end regions of the ring sectors, which end regions lie in the circumferential direction.
The ring or the ring sectors are preferably attached to the propeller hub or to the protective cover using a screw connection. It is then advantageous here if insert parts are disposed in the ring sectors, which insert parts are penetrated by at least one screw. The insert parts here are preferably at least partially surrounded by the material of the ring.
The material is preferably comprised of filler materials and binder and optionally of additives, wherein the filler material preferably has a weight proportion between 80% and 95%, wherein the binder preferably has a weight proportion between 5% and 20%, and wherein the binder is preferably comprised of a resin, in particular of epoxy resin, and a hardener, in particular of an aminic hardener. All components of the material together have 100 weight-%.
Furthermore it can be provided that reinforcing fibers are added to the material, in particular glass fibers, carbon fibers, or metallic fibers.
As mentioned reinforcing fibers can be added to the ring. In addition to the fibers mentioned these are also understood to include steel bars, meshes, reinforcing iron, cages, steel mesh, and similar elements, such as are also used with normal concrete. A mesh can also be incorporated into the material.
Concrete is a mixture of cement, aggregate, and mixing water; concrete additives and concrete admixtures are also optionally included. The cement acts as a binder to hold together the other components. The strength of the concrete is produced by crystallization of the clinker particles of the cement under water absorption.
Fibers made from steel, plastic, carbon, or glass can be added to the concrete in order to obtain fiber concrete.
In contrast to normal concrete, mineral casting (also called polymer concrete) contains a polymer, i.e., a plastic material, as binder, that holds together the aggregate. Cement is used in mineral casting, if at all, only as filler and assumes no binding effect. The most widely used polymer matrix for mineral casting is unsaturated polymer resin.
In its area of application mineral concrete has significantly better mechanical and chemical properties than cement-concrete. The setting time of these resins can be set by the amount of catalysts and hardeners used. Epoxy resin is preferably used as polymer, i.e., as binder, in order to generate a good vibration-damping behavior.
In general all materials can be used for the implementation of the proposed idea that can be cast “cold,” i.e., materials that can have a pourable consistency at room temperature (20° C.).
The invention thus provides an effective net guard for a vessel drive, in particular made from mineral casting. Here the ring can be one-part or segmented. Various separation geometries can be realized with sectors (or segments) in order to facilitate the exact connecting of sectors into a complete ring; however, the exact connection is of no great importance for the function.
The bores for attaching the rings or the sectors of the rings can be cast together during manufacturing. Inlay parts (inlays) made from various materials (for example, from stainless steel, from brass, from bronze, from aluminum, from fiberglass, from carbon-fiber-reinforced plastic, or from plastic) can also be used here. The inlays can be designed differently, serve for force transmission from the screws, and prevent the spalling of the mineral casting. In addition, further inlays can be cast together, for example, threaded-bushings and -bolts.
In order to take into account varying bore patterns and in order to cover this to the extent possible with only one mold, there are the following approaches:
Firstly slot-inlays have proven successful. These inlays can be provided straight, or curved kidney-shaped (i.e., with or without a radius in the circumferential direction). They are introduced in the mineral casting and can in particular be cast.
Inlays can also be configured as solid-material inlays. In this case they are manufactured from solid material (e.g., bronze, brass, stainless steel, plastic); they are cast together during casting of the ring or of the ring sectors. The hole pattern can then be directly introduced into the solid-material inlay, after removal of the ring or of the ring sector from the mold, according to customer specifications by drilling. Such inlays here must have an appropriate geometry in order to be securely anchored in the mineral casting.
Eccentric inlays are also possible. A bore is eccentrically introduced into this inlay; the inlay can be constructed in the manner of a sliding bearing. By turning a part of the inlay the position of the bore can be changed and thus adapted to the required connection geometry.
Mineral casting has only approximately one quarter of the density of aluminum bronze (which is 8.6 g/cm³). A significant weight reduction and thus advantages with the handling and the installation of the ring or of its sectors thereby result. Combined with the segmenting the handling- and installation-advantages increase. Manual installation is now possible. This saves the use of cranes, lifting- and assembly-tools and reduces the time consumption.
The variety of variants for the end user is maintained, but is significantly reduced for the manufacturer of the rings. By introducing the above-mentioned inlays it is possible to work with only one mold and nevertheless replicate the complete range of different hole patterns. The results are cost- and time-savings.
Thus a significant cost advantage results from the use of mineral casting instead of the material aluminum bronze used to date.

Exemplary embodiments of the invention are depicted in the drawings.

FIG. 1 shows in radial section a protective device for the stern tube seal of a vessel drive including a net guard in the shape of a ring,

FIG. 2 shows in radial section the ring (net guard) according to a first embodiment of the invention,

FIG. 3 shows in radial section and in front view the ring according to FIG. 2,

FIG. 4 shows in radial section the ring according to a further embodiment of the invention,

FIG. 5 shows in radial section the ring according to a further embodiment of the invention,

FIG. 6 shows in front view a ring sector that is a component of the ring according to a further embodiment of the invention,

FIG. 7 shows in front view four ring sectors according to FIG. 6, that together form the ring,

FIG. 8a , FIG. 8b , and FIG. 8c show as viewed from a radial perspective the joint of two adjacent ring sectors shortly before their meeting at a circumferential point of the ring,

FIG. 9 shows in radial section the ring according to a further embodiment of the invention,

FIG. 10 shows in radial section the ring according to a further embodiment of the invention,

FIG. 11 shows in front view the ring, wherein an inlay part is depicted,

FIG. 12 shows in front view the ring, wherein two slots for the attaching are depicted, and

FIG. 13 shows in front view the ring, wherein an eccentric insert for the attaching is depicted.

In FIG. 1 a stern tube seal 1 can be seen that is embodied as a multi-lip seal and includes a plurality of seal lips 13, which interact with a bush 14 that is mounted on a propeller shaft 15. The bush 14 is connected by one end via a flange 16 to the propeller hub 3 and protrudes by the other end into the stern tube 2.
The intermediate space 17 thereby formed is covered by a tubular protective cover 4, which on the one hand is fixedly attached to the stern tube 2 and a piece of which on the other hand projects over the propeller hub 3 leaving an annular gap 5.
A ring 6, U-shaped and concentric with the propeller hub 3, is disposed in the intermediate space 17 formed by the protective cover 4, which ring 6 is open radially outward, i.e., toward the protective cover 4, and is attached to the end side of the propeller hub 3 using an only schematically indicated screw connection 8. The dimensions of the ring 6 are selected such that in its receiving space formed by the U-shaped structure a plurality of winding layers of ends of fishing lines, fishing nets, etc. possibly penetrated into the annular gap 5 can be received. The stern tube seal 1 is thereby protected.
For details explicit reference is made to the above-mentioned DE 37 18 419 C2.
It is essential that according to the invention the ring 6 is at least partially comprised of a material B that can have a pourable consistency at room temperature (T=20° C.). Mineral casting is considered here in particular.
In FIG. 2 the radial section of the ring 6 can be seen. From this it follows that bores 10 are introduced in the ring 6 in order to be able to attach the ring 6 to the propeller hub 3 using screws 8. For the purpose of assembly a mounting bore 18 flush with the bore 10 is available that is provided for the passage of an appropriate tool.
It follows from FIG. 3 that the ring 6 can be configured as a one-piece part.
Insert parts 9, preferably made from metal, can be introduced into the bores or inserted into the mold during casting of the ring 6 in order to ensure stable support for the attaching of the ring 6. In particular a spalling of material of the ring 6 can thus be avoided. FIGS. 4 and 5 here show two different solutions.
In FIGS. 6 and 7 it can be seen that the ring 6 can also be comprised of a plurality of sectors 6′, 6″, 6′″, and 6″″, which each cover a circumferential section.
In order that the individual sectors accurately abut on one another in the circumferential direction and are accurately positioned in the axial direction a (see FIG. 1), centering elements 7 can be provided as are shown in FIGS. 8a, 8b, and 8c for three different variants. Accordingly the precise axial assembly of the ring sectors 6′, 6″ can be improved by the measures depicted here.
Here the transition region between two ring sectors 6′, 6″ is depicted, wherein the view from the radial direction is outlined. As can be seen from the three views according to FIGS. 8a, 8b, and 8c , the joints are not configured flat, but rather crosswise or angled (see FIG. 8a ) or in the manner of an arrow design (see FIG. 8b and FIG. 8c ). The last two possibilities mentioned ensure the precise axial assembly of the two abutting ring sectors 6′ and 6″ so that with the assembling of the ring sectors the individual parts are arranged precisely with respect to each other.
A better installability thus results, in particular with only two segments or sectors. Furthermore, there is a simple possibility of a centering of the sectors relative to one another.
In FIG. 9 an insert part 9 is outlined again that has been cast together with the casting of the ring 6 or of its sectors. In FIG. 10 it can be seen how said insert part 9 has then been pierced in order to be able to attach the ring 6 according to a desired hole pattern.
For this purpose it can be seen in FIG. 11 that an insert part 9 can be provided that includes different bores and thus makes possible the screwing-on of the ring 6 in the context of a certain variability.
The variability is increased more if—as can be seen in FIG. 12—slots 11 are provided that are configured kidney-shaped here and thus make it possible that the ring 6 can be fixedly screwed in a simpler manner
For this purpose FIG. 13 shows a still further possibility: here an insert part is provided in the form of an eccentric insert 12. This insert is formed in the manner of a sliding bearing and has two rings that can be rotated relative to each other (see arrow in FIG. 13). By turning the inner ring of the eccentric insert 12 the position of the passage bore for the screw can thus be changed and adapted to a threaded bore in the propeller hub.

REFERENCE NUMBER LIST

1 Stern tube seal
2 Stern tube
3 Propeller hub
4 Protective cover (rope guard)
5 Annular gap
6 Ring
6′ Ring sector
6″ Ring sector
6′″ Ring sector
6″″ Ring sector
7 Centering element
8 Screw connection
9 Insert part
10 Bore
11 Slot
12 Eccentric insert
13 Seal lip
14 Bush
15 Propeller shaft
16 Flange
17 Intermediate space
18 Mounting bore
B Material (mineral casting/polymer concrete)
a Axial direction

Claims

1. A protective device for a stern tube seal of a propeller-driven vessel, wherein an intermediate space is left open between a stern tube and a propeller hub, which intermediate space is covered by a tubular protective cover concentric with the propeller hub, which protective cover is fixedly anchored to the stern tube and axially overlies the propeller hub leaving an annular gap, wherein a ring concentric with the propeller hub and configured U-shaped in radial section is disposed inside the protective cover in the intermediate space between the stern tube and the propeller hub, the U-opening of which ring is directed radially outward,

and wherein the ring comprises a material that has a pourable consistency at 20° C.

2. The protective device according to claim 1, wherein the material is concrete.

3. The protective device according to claim 1 wherein the ring is comprised of at least two ring sectors, wherein each ring sector extends over a defined circumferential angle and wherein the ring sectors are connected to one another.

4. The protective device according to claim 3, wherein two, three, four, five, or six ring sectors form the ring.

5. The protective device according to claim 3 wherein the ring sectors are aligned relative to one another by centering elements, and wherein the centering elements are formed from a complementary profiling of end regions of the ring sectors lying in a circumferential direction.

6. The protective device according to claim 1, wherein the ring or the ring sectors is or are attached to the propeller hub or to the protective cover using a screw connection.

7. The protective device according to claim 6, wherein insert parts are disposed in the ring or in the ring sectors, which insert parts are penetrated by at least one screw.

8. The protective device according to claim 7, wherein the insert parts are at least partially surrounded by the material of the ring.

9. The protective device according to claim 1, wherein the material is comprised of filling materials and binder, wherein the filling material has a weight proportion between 80% and 95%, wherein the binder preferably has a weight proportion between 5% and 20%, and wherein the binder is comprised of a resin and a hardener.

10. The protective device according to claim 1, wherein glass and/or carbon and/or metallic reinforcing fibers are present in the material.

11. The protective device according to claim 1, wherein the material is mineral casting.

12. The protective device according to claim 9, wherein the resin is an epoxy resin and wherein the hardener is an aminic hardener.

13. The protective device according to claim 2,

wherein the ring comprises at least two ring sectors, wherein each ring sector extends over a defined circumferential angle and wherein the ring sectors are connected to one another,

wherein the ring sectors are aligned relative to one another by centering elements, and wherein the centering elements are formed from a complementary profiling of end regions of the ring sectors lying in a circumferential direction,

wherein the ring or the ring sectors is or are attached to the propeller hub or to the protective cover using a screw connection,

wherein insert parts are disposed in the ring or in the ring sectors, which insert parts are penetrated by at least one screw and are at least partially surrounded by the material of the ring,

wherein the material is comprised of filling materials and binder, wherein the filling material has a weight proportion between 80% and 95%, wherein the binder has a weight proportion between 5% and 20%, and wherein the binder is comprised of a resin and a hardener, and

wherein reinforcing fibers are present in the material.

14. A protective device for protecting a stern tube seal of a propeller-driven vessel, the protective device being mountable in an intermediate space between a stern tube and a propeller hub inside a protective cover adjacent an annular gap between the propeller hub and the protective cover, the protective device comprising:

a ring concentric with the propeller hub and having an outwardly facing channel with an outwardly facing opening, the ring being formed at least partially of a material that is pourable at 20° C.

15. The protective device according to claim 14, wherein the ring comprises concrete.

16. The protective device according to claim 14, wherein the ring comprises mineral casting.

17. The protective device according to claim 14, wherein the ring comprises at least two ring sectors, each ring sector extending over a defined circumferential angle.

18. The protective device according to claim 14, wherein the ring sectors are aligned relative to one another by a complementary profiling of circumferential end regions of the ring sectors.