Submarine with a thrust bearing for coupling the propulsion forces from the drive shaft into the pressure hull

Abstract

The present invention relates to a submarine with a pressure hull and a drive system, wherein the drive system has a motor, a shaft and propeller, wherein the shaft is guided through the pressure hull, wherein the shaft is guided in the interior of the pressure hull by way of a thrust bearing 10, wherein the thrust bearing 10 is configured to dissipate the propulsion force generated by way of the propeller in a manner which is transmitted to the submarine, characterized in that the thrust bearing is connected to the hull bottom 30 of the pressure hull.

Description

[0001] The invention relates to a submarine with a thrust bearing which receives the propulsive forces generated by the propeller from the shaft and directs them into the pressure hull.

[0002] Thrust bearings are also known as axial bearings, longitudinal bearings, or thrust bearings. In the context of the invention, a thrust bearing not only guides a shaft but also absorbs forces, particularly those directed along the shaft axis. "Particularly" means that while there may be small force components acting perpendicular to the shaft axis, the majority of the force (> 90%, often > 99%) acts along the shaft axis. This force vector ultimately provides the propulsion for the submarine.

[0003] Typically, a submarine has a propeller shaft extending centrally from the pressure hull. The propeller generates propulsion. However, the power is generally not intended to be transferred to the engine and then to the submarine itself. Therefore, a thrust bearing is located inside the pressure hull, which absorbs the forces from the shaft and redirects them into the vessel's structure.

[0004] Thrust bearings are now typically permanently attached to the base on which they stand. The forces are thus absorbed by the submarine's structures and primarily transferred downwards into the hull.

[0005] A disadvantage of this design, however, is that the deformation of the pressure vessel, especially at greater diving depths, leads to a change in position, so that the shaft and thrust bearing are no longer exactly parallel, but rather tilted. This, in turn, increases wear in the thrust bearing. Furthermore, it reduces operational reliability.

[0006] From CHEN FENG ET AL: "Coupled vibration characteristics of a submarine propellershaft-hull system at low frequency", JOURNAL OF LOW FREQUENCY NOISE, VIBRATION AND ACTIVE CONTROL, Vol. 39, No. 2, April 29, 2019 (2019-04-29), pages 258-279, XP093000439, ISSN: 1461-3484, DOI: 10.1177 / 1461348419846722. Found on the Internet: URL: http: / / journals.sagepub.com / doi / full-xml / 10.1177 / 1461348419846722, coupled vibration characteristics of a submarine propeller shaft-hull system at low frequency are known.

[0007] From ZHANG GANBO ET AL: "Propeller Excitation of Longitudinal Vibration Characteristics of Marine Propulsion Shafting System", SHOCK AND VIBRATION, Vol. 2014, January 1, 2014 (2014-01-01), pages 1-19, XP093000437, NL ISSN: 1070-9622, DOI: 10.1155 / 2014 / 413592, found on the Internet: URL:http: / / downloads.hindawi.com / journals / sv / 2014 / 413592.xml, the propeller excitation of the longitudinal vibration characteristics of ship propulsion shaft systems is known.

[0008] A submarine with a propulsion system is known from WO 2019 / 097 061 A1.

[0009] From CN 110 329 482 A, an external shaft device for submersible vehicles is known, and the device comprises a stern tube, a propeller shaft and a propeller, wherein the propeller shaft penetrates the stern tube, the propeller is arranged on a tail cone section of the propeller shaft, the shaft device for submersible vehicles is integrally arranged outside a cabin of a submersible vehicle, wherein the head of the stern tube is arranged on the tail end face of a pressure-resistant hull, the tail of the stern tube is arranged on a non-pressure-resistant hull, the front end of the propeller shaft is connected by a flexible coupling to an output shaft of a propulsion motor in the cabin, the flexible coupling is arranged outside the cabin, the rear end of the propeller shaft protrudes from the tail of the non-pressure-resistant hull and the propeller is positioned outside the non-pressure-resistant hull.The entire propeller shaft system of the submersible is located outside the cabin, thus minimizing the space required inside. The external propeller shaft system features a modular assembly and disassembly design, making it easy to install and remove components and facilitating maintenance of all shaft system parts. This external propeller shaft system is particularly suitable for submersibles with small tonnage, compact layouts, and limited cabin space.

[0010] The object of the invention is to provide a thrust bearing that is as wear-resistant and reliable as possible.

[0011] This problem is solved by the submarine with the features specified in claim 1. Advantageous further developments are described in the dependent claims, the following description, and the drawings.

[0012] The submarine according to the invention comprises a pressure hull and a propulsion system. The propulsion system includes a motor, a shaft, and a propeller. The motor, located inside the pressure hull, drives the shaft on which the propeller is mounted. Propulsion is generated by the rotation of the propeller. The shaft is guided through the pressure hull. A seal is located at this point, the main function of which is to withstand the diving pressure and prevent water from entering the pressure hull, while simultaneously allowing the shaft to rotate as freely as possible. Therefore, this seal is not typically designed to absorb forces from the shaft generated by the propulsion and then transmit these forces into the pressure hull. To absorb these forces, the shaft is guided inside the pressure hull by a thrust bearing. The thrust bearing is designed to transfer the propulsive force generated by the propeller to the submarine.In addition to this primary task, the thrust bearing can also have other functionalities.

[0013] According to the invention, the shaft need not be formed in one piece from the motor to the propeller. Rather, as shown later in the figures, the shaft can, for example, have a first flange connection between the thrust bearing and the motor. Likewise, as also shown later in the figures, the shaft can, for example, have a second flange connection between the thrust bearing and the propeller, in particular between the thrust bearing and the seal in the thrust body.

[0014] According to the invention, the thrust bearing is connected to the end of the pressure hull. This connection allows the thrust forces and the force of gravity from the thrust bearing to be transferred to the end. The thrust bearing is connected directly and exclusively to the end. Any further connection to other ship structures is intentionally omitted. It is therefore not connected to the bottom of the submarine or to a deck.

[0015] This means that the thrust bearing is no longer simply supported from below by gravity, but is instead attached laterally to the end floor. A supporting structure between the thrust bearing and the deck below it, or the underside of the pressure vessel, is completely eliminated. Likewise, the thrust bearing is not suspended from the upper surface of the pressure vessel.

[0016] The effect of this is that deformations of the pressure body's cylindrical shell have no direct influence on the thrust bearing's position relative to the shaft. The end plate is the end of the pressure body facing the propeller. The end plate is typically curved and concave when viewed from the inside. Even if the end plate deforms, this deformation is usually symmetrical to the central axis, so that the direct connection between the end plate and the thrust bearing prevents any tilting of the thrust bearing relative to the shaft. This significantly reduces wear.

[0017] The end cap is, for example, hemispherical. It can also be designed as a dished end, as described, for instance, in DIN 28011. A dished end has two different radii of curvature: a large radius in the central area and a radius ten times smaller at the edges. The end cap can also be designed, for example, as a basket-arch end according to DIN 28013 or as an elliptically shaped end cap. All these end caps exhibit rotational symmetry, which results in symmetrical deformation due to water pressure. The propeller shaft preferably runs along the central axis of the pressure body. The thrust bearing is also preferably located on the central axis.

[0018] The central axis is considered to be the axis around which the pressure hull is rotationally symmetrical. However, since the pressure hull of submarines is not necessarily in the form of a mathematical cylinder, the central axis, as defined in the invention, is to be understood from the perspective of the end hull. The central axis is the axis of rotational symmetry around which the end hull is rotationally symmetrical. The propeller shaft is typically located on the central axis, which is the axis of rotational symmetry of the end hull.

[0019] This prevents the thrust bearing from tilting relative to the longitudinal axis of the shaft, as the alignment between the shaft and thrust bearing is maintained even during deformation, thus minimizing wear.

[0020] Another effect is that the entire construction can be made much smaller and lighter, since the driving forces are not redirected, but can be introduced directly along the direction of force into the end floor of the pressure hull and thus via the end floor into the entire pressure hull and therefore into the entire ship structure.

[0021] According to the invention, the thrust bearing is connected to the end hull via at least four tension rods. Although the tension rods must support the thrust bearing when at rest, during movement the forces occurring are primarily directed towards the shaft, so that a high load occurs as tension and can thus be introduced directly and efficiently into the thrust hull rather than via a connection of the thrust bearing to the deck or the bottom of the submarine.

[0022] A tension member, in the context of a connection, is a connection specifically designed to absorb tensile and compressive forces. Tension members can be designed as rods or tubes. They do not necessarily have to be round; they can also have a square cross-section or, for example, be designed as I-beams. Tension members can be designed or connected in such a way that they are specifically designed to absorb tensile and compressive forces without being subject to moments. The tension member can be rigidly or rotatably connected to the end plate. The tension member can also be designed, for example, as an eye bar.

[0023] In an unclaimed embodiment, the thrust bearing can be connected to the end base via a cone, a conical cutout, or via two or more conical segments.

[0024] The following section discusses the claimed embodiment with tension rods. The embodiments described below can be implemented analogously with a cone or conical segments. Tension rods and conical segments can also be combined.

[0025] In a further embodiment of the invention, the tie rods are rotatably connected to the thrust bearing. For example, and in particular, the tie rods are rotatably attached to the thrust bearing via pins. The pins are advantageously arranged laterally on the thrust bearing, so that movement of the thrust bearing is possible within the vertical median plane. The shaft also lies within the vertical median plane. The vertical median plane is thus the plane which, in the submarine's normal position, runs perpendicularly through the center of the submarine and therefore also through the center of the shafts.

[0026] In a further embodiment of the invention, the tension rods are arranged on a circular path of the end plate. Preferably, the circular path has its center point on the central axis of the pressure body. This ensures that the force is coupled into the end plate in a rotationally symmetrical manner. Due to the arrangement on a circular path, all connection points are rotationally symmetrical. Because of the rotationally symmetrical shape of the end plate, any deformations of the end plate are also to be expected to be rotationally symmetrical. Therefore, a deformation of the end plate results at most in a longitudinal displacement of the thrust bearing along the shaft axis. Tilting between the shaft and the thrust bearing, particularly between the thrust bearing races, and thus an increase in wear, does not occur.

[0027] In a further embodiment of the invention, the tension rods are arranged symmetrically to the vertical central plane.

[0028] In a further embodiment of the invention, at least two tension rods are arranged on the horizontal central plane.

[0029] In a further embodiment of the invention, the thrust bearing has two opposing pins on its longitudinal side, with the tension rods being attached to each pin. This allows the thrust bearing to be mounted so as to be rotatable about the transverse axis of the boat.

[0030] In another exemplary embodiment of the invention, the thrust bearing is connected to the end plate via a first tie rod, which is arranged in the vertical central plane and extends downwards from the thrust bearing at an angle of, for example, 45°. The thrust bearing is further connected to the end plate via a second tie rod, which is arranged in the vertical central plane and extends upwards from the thrust bearing at an angle of, for example, 45°. The thrust bearing is also connected to the end plate via two further tie rods, which are arranged horizontally and also extend at a 45° angle. The angles are specified with respect to the shaft axis. Thus, all tie rods are attached to the end plate along a circular path. In the rest state, the first tie rod is subjected to a compressive load and the second tie rod to a tensile load due to gravity. During thrusting, a tensile force due to the thrust is added to all tie rods.

[0031] In another exemplary embodiment of the invention, the thrust bearing has two laterally arranged, rotatable attachment points for tie rods, which are, for example, in the form of round pins. At each pin of the thrust bearing, the thrust bearing is connected to the end plate via a first tie rod, which is arranged parallel to the vertical center plane and extends downwards from the pin at an angle of, for example, 45°. Furthermore, at each pin of the thrust bearing, the thrust bearing is connected to the end plate via a second tie rod, which is arranged parallel to the vertical center plane and extends upwards at an angle of, for example, 45°. Finally, the thrust bearing is connected to the end plate via two further tie rods, which are also each attached to the pins. These tie rods are arranged horizontally and also extend at a 45° angle.Thus, all tension rods are attached to the end floor on a circular path.

[0032] In In another exemplary embodiment of the invention, the thrust bearing has two laterally arranged, rotatable attachment points for tie rods, which are, for example, in the form of round pins. At each pin of the thrust bearing, the thrust bearing is connected to the end plate via a first tie rod, which is arranged parallel to the vertical center plane and extends downwards from the pin at an angle of, for example, 45°. Furthermore, at each pin of the thrust bearing, the thrust bearing is connected to the end plate via a second tie rod, which is arranged parallel to the shaft. Finally, the thrust bearing is connected to the end plate via two further tie rods, which are also each attached to the pins. These tie rods are arranged horizontally and also extend at a 45° angle.In this embodiment, the tension rods arranged parallel to the shaft can absorb the tensile force generated by the thrust of the propeller particularly well without force diversion.

[0033] In another exemplary embodiment of the invention, the thrust bearing has two laterally arranged, rotatable attachment points for tie rods, which are, for example, in the form of round pins. At each pin of the thrust bearing, the thrust bearing is connected to the end plate via a first tie rod, which is arranged parallel to the vertical center plane and extends downwards from the pin at an angle of, for example, 45°. Furthermore, at each pin of the thrust bearing, the thrust bearing is connected to the end plate via a second tie rod, which is arranged parallel to the vertical center plane and extends upwards at an angle of, for example, 45°. Finally, the thrust bearing is connected to the end plate via two further tie rods, which are also each attached to the pins. These tie rods are arranged horizontally and also extend at a 45° angle.In addition, the thrust bearing is connected to the end base at both journals of the thrust bearing via a further tie rod, which is arranged parallel to the shaft.

[0034] In a further embodiment of the invention, the tension rods are designed with at least three parts. The tension rod has a front section and a rear section. The front and rear sections are connected to each other by at least one length-adjustment device. In particular, this device can be a threaded sleeve that engages a thread on both the front and rear sections and changes the length by rotation, preferably with the two threads running in opposite directions. This allows for easy adjustment and alignment of the thrust bearing to the individual submarine, thus compensating, for example, for variations in the dimensions of the end cap or the shaft during installation. Additionally, changes that occur during operation can also be detected and corrected.

[0035] Spatial relationships in this text always refer to a normal position of the pressure hull, i.e., a horizontal orientation of the pressure hull's central axis, i.e., the normal position in calm seas when surfaced and without movement.

[0036] The submarine according to the invention is explained in more detail below with reference to exemplary embodiments shown in the drawings. Fig. 1 first exemplary embodiment Fig. 2 second exemplary embodiment

[0037] In Fig. 1 Figure 1 shows a first exemplary arrangement of a thrust bearing 10 in a submarine. For simplification, a section of the submarine's pressure hull, specifically the end plate 30 with the thrust bearing 10 attached to it, is shown. The thrust bearing 10 has a pin 70 on each of its two sides. Three tie rods 20 are attached to each pin 70: one at a 45° downward angle, one at a 45° upward angle, and one at a sideways angle of less than 45°. All six tie rods 20 are connected to the end plate 30, with the connection points between the tie rods 20 and the end plate 30 lying on a circular path and thus all equidistant from the axis of rotation of the shaft. To facilitate fitting the tie rods 20, each tie rod 20 has a threaded sleeve 60. The length of each tie rod 20 can be changed by rotating the threaded sleeve 60.

[0038] Furthermore, the end cap 30 has a pressure hull penetration 40 through which the shaft is guided from the interior of the pressure hull to the outside. The pressure hull penetration 40 is sealed against the immersion pressure but allows the shaft to rotate freely. On the other side of the thrust bearing 10, the shaft has a coupling flange 50 for connection to the motor via another section of the shaft. Specifically, an axially and radially elastic coupling element is first arranged on the coupling flange. This protects the propulsion motor. Due to the thrust bearing 10, the thrust force of the propeller no longer acts on the coupling flange 50 and thus no longer on the motor.

[0039] Fig. 2 A second alternative exemplary arrangement of a thrust bearing 10 in a submarine is shown. The difference to the one in Fig. 1 The first embodiment shown is that the two in Fig. 1In this embodiment, the upward-pointing tension rods 20 run parallel to the shaft. This allows these two parallel tension rods to efficiently transfer the tensile forces from the propeller's propulsion to the end plate without force redirection. Reference sign

[0040] 10 Thrust bearing 20 Tension rod 30 End cap 40 Pressure body feedthrough 50 Coupling flange 60 Threaded sleeve 70 Pin

Claims

1. Submarine comprising a pressure hull and a propulsion system, wherein the propulsion system comprises a motor, a shaft and a propeller, wherein the shaft passes through the pressure hull, wherein the shaft is guided inside the pressure hull by a thrust bearing (10), wherein the thrust bearing (10) is designed to transmit the propulsive force generated by the propeller to the submarine, characterised in that the thrust bearing is connected to the end plate (30) of the pressure hull, wherein the thrust bearing (10) is connected to the end plate (30) via at least four tie rods (20).

2. Submarine according to claim 1, characterised in that the tie rods (20) are connected to the thrust bearing (10) in a manner permitting rotational movement.

3. Submarine according to one of claims 1 to 2, characterised in that the tie rods (20) are arranged on a circular path of the end plate.

4. Submarine according to any one of claims 1 to 3, characterised in that the tie rods (20) are arranged symmetrically with respect to the vertical centre plane.

5. Submarine according to any one of claims 1 to 4, characterised in that two tie rods (20) are arranged on the horizontal centre plane.

6. A submarine according to any one of claims 1 to 5, characterised in that the tie rods are of a three-part design, wherein the tie rod comprises a front tie rod section and a rear tie rod section, wherein the front tie rod section and the rear tie rod section are connected to one another via at least one device for adjusting the length.

7. A submarine according to claim 6, characterised in that the device for adjusting the length is a threaded sleeve (60).

8. A submarine according to any one of claims 1 to 6, characterised in that the thrust bearing (10) has two opposing pins on the longitudinal side, the tie rods (20) being secured to the pins respectively.

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