WO2005010352A2

WO2005010352A2 - Drive for a working machine to be applied under water

Info

Publication number: WO2005010352A2
Application number: PCT/DE2004/001381
Authority: WO
Inventors: Jan Wegner
Original assignee: Stiftung Alfred-Wegener-Institut Für Polar- Und Meeresforschung
Priority date: 2003-07-17
Filing date: 2004-06-27
Publication date: 2005-02-03
Also published as: DE10333513A1; WO2005010352A3; DE10333513B4

Abstract

The operation of devices for measurements and experiments in the sea requires energy for various consumers. The aim of the invention is to produce a discontinuous operation drive which is suitable for all water depths and can be charged once with the required amount of energy. Said aim is achieved, whereby a drive (1) for a working machine to be applied under water, particularly, in the deep sea, is provided, whereby the power transmission device (2) consists of a driven shaft (6), a coupled rope winch (7) with a cable (8) which can be rolled up, transmission elements and an ratchet mechanism (20), the floating body (11), at the free end of the rope, being a closed, incompressible floatation sphere (12) which can be loaded with buoyancy energy. During the lowering of the drive (1), potential energy is absorbed by means of the stopped floating body (11) and, after the placement of the drive (1), said energy may be converted into a mechanical work by a controlled release of the ratchet mechanism (20).

Description

Drive for a machine in underwater use

description

The present invention relates to a drive for a work machine in underwater use with a power transmission device with an output shaft and a buoyancy body as an energy source.

All layers of the sea from surface to deep into the sediments on the seabed are the subject of measurements, sampling and experiments of all kinds. This includes measuring devices for recording physical, biological and chemical parameters, samplers for taking material for laboratory tests and experiments to investigate the effects targeted influencing of the environment. Energy is required to operate these devices. The main energy consumers are drives of all kinds, e.g. for filling and closing sample vessels, for moving robotic arms, for moving on the sea floor and for penetrating the test material. Furthermore, energy is required for the operation of light sources for the use of imaging processes, sensors, data processing, signal processing, etc.

While the latter only require electrical energy from batteries or also from the surface via cables, drives can also obtain their energy from alternative power sources. Spring accumulators with mechanical or gas springs are particularly worthy of mention here, which are quickly charged before use and slowly discharged on site via reducing devices over a planned time on the working machine. Batteries for deep-sea use must be designed to be pressure-resistant and are therefore heavy and expensive, in addition to insulation problems in the areas of connectors and cables. Mechanical stores often have due to their design principles, an unfavorable energy-mass ratio and are expensive. If necessary, they can contribute to the basic weight and reduce the required ballast. Another form of alternative sources of power are buoyancy bodies. A floatable body that is brought into the water exerts a depth-independent, upward force that can be used for propulsion purposes.

The Archimedean principle of buoyancy states that a body is immersed in the water until the weight of the displaced water corresponds to the total weight of the immersed body. A body with a specific weight greater than water will perish. A floatable body pressed under water will counteract the downward force as the buoyancy force between the weight of the water displaced during swimming and the weight of the water displaced when fully submerged. The buoyancy force is calculated from the volume of the buoyancy body multiplied by the specific weight of water minus the dead weight of the buoyancy body. As long as the result is positive, there is an upward force. If the result is zero, the body floats weakly in every water depth. If the result is negative, the body sinks. These considerations neglect the fact that water is compressible to a small extent and is compressed by approx. 0.45% per 1000 m depth

(Compressibility ß = 4.4 x 10 ^"0 / Pa), whereby its specific weight and thus the buoyancy force increases slightly on a body that is not, or also negligibly, compressible. Then, for example, a 10 kg heavy air-filled hollow body with 40 liters Total volume at any depth will result in a buoyancy of approximately 294 N. This force is practically constantly available for use even over great water depths, eg 6000 m and more

Drives with buoyancy bodies, or buoyancy drives for short, work with little loss, since they only cause frictional resistance and no energetic conversions have overcome. Such buoyancy drives can exist in all such media combinations that have a sufficient difference in specific weights and that allow the necessary movement. The media combination can therefore be two gases, a liquid and a gas or vacuum, two liquids or a liquid and a solid. Solid plastics or possibly expensive syntactic foams can be used. Buoyancy bodies made of composite materials are also conceivable. Naturally, the combination of a liquid and a gas or vacuum achieves the highest buoyancy. For practical reasons, buoyancy drives with water as a liquid and air as a gaseous medium are of the greatest importance. The way the buoyancy drive works reverses the weight drive, e.g. an old grandfather clock.

For example, the patent specification GB 2 190 965 A (compressed air or gas powered buoyancy machine) describes a continuously operating buoyancy drive. Floating bodies that are open on one side are attached to a belt running over two rollers. The buoyancy drive is in a water tank and one of the rollers is equipped with an output shaft. The belt that runs over the rollers and the output shaft represent the power transmission device. The upward open buoyancy bodies are filled with compressed air from a line protruding into the water tank as they pass through bottom dead center, and drive the belt until they reach top dead center turn its open end up, lose air, and go empty down. The whole buoyancy drive is based on the constant supply of air, e.g. presses from a tank under low pressure through the line under the buoyancy body. The machine only works economically if the air e.g. is available as a waste product from another process.

From the document DE 39 09 154 C2 (device for generating a rotary movement by means of a submerged in a liquid column and a floating body rising therein), from which the present invention is based as the closest prior art, a continuously operating, revolving buoyancy drive is also known. Here, the working energy is supplied by the water that constantly flows in at the top, which is lost at the bottom by draining off the water present in the plunge chamber necessary for changing the air-filled buoyancy body that is open at the bottom. The coupling chamber is flooded to connect a buoyancy body to the buoyancy belt standing in the water-filled tank and then sealed again. The chamber is emptied downwards to insert a new air-filled buoyant body from the driven belt in the empty tank. Up and down belts and the coupling elements form the power transmission device. At least one of the axes of the rollers carrying the revolving belts is the output shaft. The buoyancy work is done by coupling the belts from the buoyancy belt to the driven belt, to the mechanisms for translating the buoyancy bodies from the buoyancy belt to the driven belt and to moving the buoyancy bodies from the driven belt to divided the diving chamber and for opening and closing the valves of the diving chamber. However, even with some size of the entire arrangement, only a little measurable drive energy remains for a working machine on the output shaft.

The buoyancy drives presented in the literature always work continuously and are dependent on a constant external energy supply. They have open and therefore compressible buoyancy bodies. They can therefore only work in shallow water and are not suitable for scientific use on the seabed, especially at greater or greater depths. It is therefore the object of the present invention to develop the drive described at the outset for a work machine in underwater use with a power transmission device with an output shaft and a buoyancy body as an energy source in such a way that a discontinuously operating drive is produced, each with an amount of energy required for a defined work under water unique can be loaded. The drive should be suitable for everyone, but especially for greater water depths, simple to set up, safe and reliable in operation and easy to handle.

To solve the problem in a generic drive for a machine in underwater use according to the invention, the power transmission device consists of a cable pulley firmly connected to the output shaft, a cable that can be unwound from the cable pulley, force-coupling elements non-positively connected to the output shaft, and one when the drive is lowered on a support cable in Water-engaging, controlled releasable latching of the rope pulley and the buoyancy body by a closed, incompressible, with a coiled rope and a latched rope pulley with a body which is chargeable by buoyancy, depth of dive and unwindable rope length certain body with an arrangement at the free rope end, the working machine and / or the drive has a weight that more than compensates for the buoyancy.

With the drive according to the invention, a reliably working discontinuous drive is made available which automatically absorbs energy into an energy store in the form of a buoyancy body during the lowering into its working depth and then releases it again in a controlled manner during work. Then the energy storage must be recharged by bringing the drive back to the water surface and winding the rope. The drive has a high degree of efficiency because it is without

Energy conversion needs, it is environmentally friendly because it works with renewable energy and it is easy to handle. Compared to electrical systems, it shows no loss of energy due to self-discharge and is therefore particularly suitable for long-term use. The "drive by buoyancy" thus fulfills all requirements of a modern one

Drive system, especially for experimental research. For scientific experiments on the sea floor at hundreds to thousands of meters, it is important to carry out a planned experiment scientifically and technically correct, but with little effort in equipment and energy. The logistical effort for the large number of projects on board research ships during the precisely scheduled research trips is great and every saving in costs and ship time is welcome. In addition, budgets are limited, and the cheaper an experiment can be carried out, the more versatile research can be. For the provision of energy in the deep sea, either very expensive and heavy high-pressure-resistant or pressure-compensated batteries or very long, error-prone supply lines from the water surface are required. With the cable variant in particular, the energy supply from a research ship is generally guaranteed. As a result, the ship is bound for the duration of the experiment and the very expensive ship time is heavily used. There are also special requirements with regard to the maneuverability of the ship. For this reason, wired experiments are severely restricted and the use of autonomously operating systems is preferred. In order to save energy, battery-operated autonomous systems often dispense with the particularly complex imaging methods for controlling experiments or only generate a still image at longer intervals. Sensor or time controlled, automatic tests are preferred. In many cases, only drive energy is required to actuate penetration or locking mechanisms, grippers, traversing devices or robot arms. Instead of expensive electric motors with the problem, for example, of pressure-resistant shaft seals for actuating such elements, it is therefore the basic idea of the present invention to provide a limited, precisely calculable, non-aging source of potential energy, which does mechanical work via corresponding mechanical transmission elements can afford. The buoyancy body, which in the invention is designed as a non-compressible body, generates in the water depth a buoyancy force which is dependent on its size and which, via a rope and placed a pulley on an output shaft and provided with mechanical control means, can perform a whole range of tasks. The drive according to the invention is charged with potential energy by fastening the buoyancy body to the free end of the rope which is long on the pulley and corresponding to the intended diving depth of the drive, and by lowering it onto the water bed. The entire working machine, due to its basic weight, which is required anyway for safe positioning on the bottom of the body of water, with additional ballast, is sufficiently heavy to overcome the lifting force when lowering. Immediately at the start of the lowering, the buoyancy body releases its driving buoyancy. So that the entire buoyancy energy is available to the experiment on the water floor, a device must be available which prevents the buoyancy body from unwinding the rope prematurely during the lowering and which only releases the buoyancy body when it reaches the position on the seabed. A latch is suitable for this purpose, which reliably secures the rope pulley during the process of lowering the working machine. After stopping at the bottom of the body of water, the drive according to the invention is activated by a controlled release of the rope pulley and contributes to carrying out correspondingly planned and constructed experiments.

The external shape of the buoyancy body is fundamentally not relevant, but it is an advantageous further development of the drive according to the invention if the buoyancy body is formed by at least one commercially available buoyancy ball. Such buoyancy balls are tested for pressure resistance for the required immersion depth of the drive, have an outer protective cover against damage during handling on board and have coupling points for the rope. They are also commercially available in various sizes and are relatively inexpensive. The drive energy that can be implemented depends on the total volume of the buoyancy body, its own weight, the developable cable route from the bottom up to the surface of the water and the cable weight. there For example, the buoyancy body can also be formed from several individual bodies arranged in any arrangement on the rope. If, according to a further development of the invention idea, the rope consists of a largely buoyancy-neutral material, the rope weight is only slightly influenced by the resulting buoyancy force and causes hardly any loss of drive energy. Since a rope material that is specifically buoyant at all depths is in principle not available, an aramid rope can be used here, for example, which has a particularly favorable ratio of resilience to its own weight under water.

The drive energy provided by the buoyancy body via the power transmission device consisting of the rope, the rope pulley, the output shaft and the power coupling elements must be supplied to the driven machine to be driven. For this purpose, according to a further embodiment of the drive according to the invention, it can advantageously be provided that the force coupling elements are designed as a gearwheel, V-belt pulley, eccentric pulley, cam disk, cam disk or worm wheel. The aforementioned selection of force coupling elements can be connected to the output shaft in a form-fitting manner via generally customary connections such as feather keys, flanges, molded pinions, etc. or by means of pressing or gluing. The specified design options are only examples of any structural combinations of mechanical elements that take into account the requirements of the respective experiment and the conditions under water. In principle, any mechanical task can be mastered, the embodiments are only limited in terms of effort.

According to a further advantageous development of the drive according to the invention, the output shaft equipped with permanent magnets, the rotor and a bearing of the output shaft equipped with coils can form the stator of an electrical generator. The electrical energy that can be generated by the drive according to the invention of up to a few 100 W can be used by consumers are available that cannot work with mechanical energy, for example devices for data processing and transmission, sensor supply, lighting and image recording devices and / or the control of actuators for mechanical energy distribution.

According to further advantageous developments of the drive according to the invention, it can also be provided that the latch, which holds the force transmission device and the associated buoyant body when lowering, is formed by a locking pawl which engages in a ratchet wheel fixed on the output shaft, the latching by a when the drive is placed on a body of water actuated unlocking device is automatically released and that the unlocking device has a delay device operated by a clock spring to release the latch. The latching serves to prevent the rope from unwinding prematurely with the buoyancy device when the machine is lowered onto the water bed. It is therefore necessary to have an unlocking device which functions reliably, for example by being placed on the water bed, and which releases the latching. Due to sediment turbulence caused by touching down on a sea floor, it may make sense to start the experiment only after a waiting period, i.e. to activate the drive with a time delay. For this purpose, a mechanical delay device, which runs like a clockwork and is spring-actuated, can advantageously be introduced between the unlocking device and the latching device in such a way that the unlocking device triggers the mechanism of the delaying device and, after its expiration, the latching device is released. The unlocking device can also be triggered by a simple electronic device control with minimal electrical energy equipment.

Finally, according to a further advantageous continuation of the drive according to the invention on the power transmission device, one can use the power coupling elements or an electronic control device controllable braking device that regulates the delivery of the drive energy. The speed at which the pulley rotates and thus drives the machine will, without further precautions, only depend on the speed at which the float rises to the water surface. However, this in turn is only dependent on the buoyancy force, the flow resistance of the buoyancy body and the rope and the frictional resistances in the power transmission device and the experiment. For a fixed predetermined course of an experiment, however, it is advantageous if, regardless of these different circumstances, there is a controllable inhibition of the running speed in the form of a braking device which more or less throttles the rotation of the rope pulley according to the respective requirements of the experiment. In addition, intermittent operation with breaks in between can be realized and the delivery of the drive energy can be controlled in a targeted manner. The brake device can be designed, for example, in a controllable version as a modified drum brake with brake shoes acting directly on the output shaft, as a disc brake with a brake disc firmly mounted on the output shaft and brake shoes acting on this or as an eddy current brake utilizing the generator. Brake devices that cannot be further controlled, for example impellers that use the water resistance and are arranged on the output shaft or on the pulley, can also be used.

Finally, it can advantageously be provided that a further unlocking device, which can be controlled by the force coupling elements or by an electronic control device, is disposed on the power transmission device. As a rule, after the end of the experiment, but generally at any selectable point in time, the entire working machine can be brought back to the water surface for various reasons. Then it makes sense to use the float to catch up. For this purpose, another unlocking device can be triggered, the neutral ballast from the Machine releases and ensures that the buoyancy outweighs the weight of the machine. When lifting off the ground, the latch engages again and prevents the rope from unrolling further from the rope pulley, provided there is still rope supply. When the buoyancy body has reached the surface of the water, the drive machine and thus the experiment with the data obtained can be recovered from the rope of the buoyancy drive.

Forms of embodiment of the invention are explained in more detail below with reference to the schematic figures. It shows

Figure 1 shows a drive according to the invention with a generator, a latch and a braking device in perspective,

2a-2b a drive according to the invention with latching and unlocking device in two positions, FIG. 3 a drive according to the invention with unlocking device with delay, and FIGS. 4a-4d a drive according to the invention with a selection of power coupling elements.

Figure 1 shows a drive 1 according to the invention schematically in a perspective view. A power transmission device 2 is mounted on a base plate 3 of a work machine, not shown, and is anchored, for example, by its own weight, on the bottom 4 of a sea 5. A cable pulley 7 connected to an output shaft 6 carries the entire intended length of a cable 8, the maximum the depth of the machine can be. In the lowered state before starting work, the rope 8 is completely wound onto the rope pulley 7 and the drive 1 is locked. The output shaft 6 rests in bearings 9 on the Base plate 3 are fixed. The end of the cable 8 forms a fastening device 10, for example a snap hook, for a buoyancy body 11. If several buoyancy bodies 11 are provided, a plurality of fastening devices 10 can be present in parallel or one above the other. The buoyancy body 11 has the shape of a commercially available buoyancy ball 12 made of glass with a protective cover 13 with protective ribs 14 and an eyelet 15 for coupling to the fastening device 10 of the cable 8.

In the present exemplary embodiment, the output shaft 6 equipped with permanent magnets is the rotor 16 of an electrical generator 17, the stator 18 of which forms the bearing 9 with integrated coils. Magnets and coils are not shown here. The electrical energy is tapped at the connections 19 and is used, for example, to control the force distribution with mechanical actuators, the sensor supply, data transmission devices and other consumers in the experiment that cannot work with mechanical energy.

Furthermore, a latch 20 and a braking device 39, which is shown in more detail in FIG. 2a and FIG. 2b, are shown schematically.

FIG. 2 schematically shows a drive 1 with a latch 20 and an unlocking device 21, which is automatically activated when it is placed on the water bed 4. FIG. 2a shows the latched state during the lowering (indicated by two downward-pointing arrows) of the drive 1, mounted on the base plate 3. The rope pulley 7 with the rope 8, on which the buoyancy body 11 (not shown here) pulls upwards, is firmly connected to the output shaft 6. On the output shaft 6, a ratchet wheel 22 is fixed, in which a locking pawl 23 engages and thus prevents the pulley 7 from running off. The locking pawl 23 is supported via an axis of rotation 24 and an unlocking lever 25 on a fixed block 26 and is pressed by a return spring 27. The Unlocking lever 25 sits on a further axis of rotation 28 and is in turn pressed against the block 26 by a further return spring 29.

FIG. 2b shows the unlocked state after the drive 1 is placed on the floor 4. The unlocking lever 25 is rotated counterclockwise by its placement force about its further axis of rotation 28 into a position flush with the base plate 3. The unlocking lever 25 presses the locking pawl 23 upward and rotates it clockwise about its axis of rotation 24. As a result, the locking pawl 23 finally releases the ratchet wheel 22 and the rope pulley 7 can act on the rope due to the buoyancy of the buoyancy body 11 (not shown here) 8 start to spin. When the drive 1 is lifted off the floor 4 again (for example after dropping ballast), the locking pawl 23 is turned back into its original positions by its return spring 27 and the unlocking lever 25 by its further return spring 29, comes into contact with the block 26 and the locking lever 23 engages back into the ratchet wheel 22. The drive 1 is locked again and the device can be recovered on the rope 8 after floating.

FIG. 3 also schematically shows a drive 1 with a latch 20, an unlocking device 21 and a delay device 30. When it comes into contact with the ground, the unlocking device 21 triggers and starts the spring-operated drain mechanism of the delay device 30. After the spring mechanism has expired, the delay device 30 in turn actuates the latch 20 and unlocks drive 1. After loosening the ground contact, the entire actuation chain falls back into its original state and drive 1 is locked again.

FIGS. 4a to 4d show a drive 1 according to the invention with various force coupling elements, each with specific tasks for the experiment to be driven. In Figure 4a, a gear 31 is shown, the can drive another gear 32 or a chain to reverse the direction of rotation. FIG. 4b shows a V-belt pulley 33 with a V-belt 34, for example as a transmission belt with a constant direction of rotation. FIG. 4c shows an eccentric disk 35 on the end face, with which an oscillating movement can be generated via a suitably mounted articulated lever 36. FIG. 4d finally shows a cam disk 37, with the aid of which any control movement can be generated depending on the angle and with a variable stroke by means of a rocker arm 38. Other forwarding elements such as cams, screws, downstream gears, etc. are also possible.

LIST OF REFERENCE NUMBERS

1 drive 2 power transmission device

3 base plate

4 water bed

5 sea

6 output shaft

7 pulley

8 rope

9 bearings

10 fastening device

11 buoyancy bodies

12 buoyancy ball

13 protective cover protective ribs

eyelet

rotor

generator

stator

latching

unlocking

ratchet

locking pawl

axis of rotation

release lever

block

Return spring further axis of rotation further return spring

delay means

Gear another gear

pulley

fan belt

eccentric

articulated lever

cam

rocker arm

braking device

Claims

claims

1. Drive for a machine in underwater use with a power transmission device with an output shaft and a buoyancy body as an energy source, characterized in that the power transmission device (2) from a cable pulley (7) firmly connected to the output shaft (6), one of the cable pulley (7) Unwindable rope (8), non-positively connected force coupling elements to the output shaft (6) and a controlled releasable latching (29) of the rope pulley (7) and the buoyancy body (11) engaging in the water when the drive (1) is lowered on a support rope closed, incompressible, with coiled rope (8) and pinned rope pulley (7) with a certain amount of buoyancy energy chargeable by buoyancy, diving depth and developable rope length with an arrangement at the free end of the rope is formed, the machine and / or the drive (1) a die Buoyancy overcompensating weight.

2. Drive according to claim 1, characterized in that the buoyancy body (11) is formed by at least one commercially available buoyancy ball (12).

3. Drive according to one of claims 1 or 2, characterized in that the rope (8) consists of a largely buoyancy-neutral material.

4. Drive according to one of claims 1 to 3, characterized in that the force coupling elements as a gear (31), eccentric (35), cam (37), cam, V-belt pulley or worm wheel are formed.

5. Drive according to one of claims 1 to 4, characterized in that the output shaft (6) equipped with permanent magnets, the rotor (16) and a bearing of the output shaft (6) equipped with coils, the stator (18) of an electrical generator (17) form.

6. Drive according to one of claims 1 to 5, characterized in that the latch (20) is formed by a locking pawl (22) engaging in a ratchet wheel (22) fixed on the output shaft (6).

7. Drive according to one of claims 1 to 6, characterized in that the latch (20) is automatically released by an unlocking device (21) actuated when the drive (1) is placed on a water bed (4).

8. Drive according to claim 7, characterized in that the unlocking device (21) has a delay device (30) operated by a clock spring for releasing the latch (20).

9. Drive according to one of claims 1 to 8, characterized in that a controllable by the force coupling elements or by an electronic control device, the delivery of the drive energy regulating braking device (39) is arranged on the power transmission device (2).

10. Drive according to one of claims 1 to 9, characterized in that on the power transmission device (2) is controlled by the force coupling elements or by an electronic control device, ballast-shedding further unlocking device.