GB2605790A

GB2605790A - Apparatus for converting buoyancy forces of a gas in a liquid into mechanical torque

Info

Publication number: GB2605790A
Application number: GB2105181.8A
Authority: GB
Inventors: Stewart Paul
Original assignee: Individual
Current assignee: Individual
Priority date: 2021-04-12
Filing date: 2021-04-12
Publication date: 2022-10-19
Also published as: GB202205250D0; GB2607183A; GB202105181D0

Abstract

A gas powered motor comprises a liquid chamber 2 containing a gas manifold 18 provided with a gas supply. A buoyancy vessel 16 is movable in the liquid chamber and arranged to receive gas from the gas manifold 18, and includes an escape valve 17. The buoyancy vessel 16 is tethered to a drive shaft 8 by a flexible element 13 wound about the drive shaft. Movement of the vessel 16 drives the shaft 8 in one direction by a ratchet mechanism. A second flexible element 14 is wound in an opposite sense about the drive shaft and connected to a counterweight arrangement 26 to rotate the drive shaft 8 to rewind the flexible element 13 onto the drive shaft 8.

Description

APPARATUS FOR CONVERTING BUOYANCY FORCES OF A

GAS IN A LIQUID INTO MECHANICAL TORQUE

TECHNICAL FIELD OF THE INVENTION

This invention relates to apparatus for converting buoyancy forces of a gas in a liquid into mechanical torque which can be used to drive an electricity generator.

BACKGROUND

Electricity generators are used in remote locations in many parts of the world where there is no convenient access to an electricity supply grid, such as on ships for example. Such generators are commonly driven by a petrol or diesel engine which provides the torque to operate an AC or DC generator. However, with fossil fuels in increasingly short supply, and environmental concerns over atmospheric pollution, there is a requirement for a clean, efficient and compact apparatus for producing the necessary torque. -2 -

SUMMARY OF THE INVENTION

When viewed from one aspect the present invention proposes apparatus for converting buoyancy forces of a gas in a liquid into mechanical torque: - a liquid chamber (2), - a gas manifold (18) in the liquid chamber, - a gas supply (3) for the gas manifold, - a buoyancy vessel (16) movable in the liquid chamber and arranged to receive gas from the gas manifold, - a rotatable member (8), - a first flexible element (13) wound about the rotatable member (8) and tethered to said buoyancy vessel (16) such that the buoyancy vessel rotates the rotatable member, - a return arrangement (14, 25, 26) to rotate the rotatable member (8) in an opposite sense to the buoyancy vessel (16) such as to rewind the first flexible element (13) onto the rotatable member (8).

In a preferred embodiment the return arrangement includes a second flexible element (14) which is wound about the rotatable member (8) in an opposite sense to the first flexible element (13).

In a preferred embodiment the second flexible element (14) is connected to a counterweight arrangement (26).

In a preferred embodiment the buoyancy vessel (16) includes an -3 -escape valve (17) to release gas therefrom.

In a preferred embodiment an output shaft (5) is coupled to the rotatable member (8) via a one-way clutch arrangement (12a, 12b).

In a preferred embodiment a plurality of such liquid chambers (2) have their respective rotatable members (8) coupled to the output shaft (5).

In a preferred embodiment said plurality of liquid chambers (2) are mutually interconnected.

In a preferred embodiment the output shaft is arranged to drive an electricity generator (6).

BRIEF DESCRIPTION OF THE DRAWINGS

The following description and the accompanying drawings referred to therein are included by way of non-limiting example in order to illustrate how the invention may be put into practice. In the drawings: Figure 1 is a general view of apparatus for converting the buoyancy forces of a gas in a liquid into mechanical torque; -4 -Figure 2 is a general view of part of a drive arrangement which is provided for each chamber of the apparatus; Figure 3 is another general view showing part of the interior structure of the chambers; Figure 4 is a general external view of one of the chambers; Figure 5 is a ghost view of the lower part of the chamber; Figure 6 is a similar ghost view of the upper part of the chamber.

DETAILED DESCRIPTION OF THE DRAWINGS

Referring firstly to Fig. 1, the apparatus include a panel-like casing 1 which contains a number of vertically disposed chambers 2. The chambers may be open at the top and are conveniently arranged side-by-side in a row. An air supply 3, e.g. an air blower, pump, compressor, or pressurised air tank, is located at one end of the branched pipe 4 to supply air to each of the chambers 2. At the opposite end of the casing 1 an output shaft 5 supplies mechanical torque to drive an AC or DC generator 6 of the kind which produces electricity by electromagnetic induction. The opposite end of the output shaft 5 may be provided with a starter 7 such as a small starter motor or hand crank for example. -5 -

Referring to Fig. 2, at the bottom of each of the chambers a respective rotatable member in the form of a drive shaft 8 is mounted in bearings 9. The drive shaft extends through opposite walls of the chamber, one of which ends turns the output shaft 5 via enmeshed gears 10 and 11. Gear 10 and/or gear 11 is mounted on the respective shaft via a suitable one-way clutch bearing 12a, 12b such as a ratchet, needle roller, sprag clutch etc. First and second flexible elements 13 and 14 are wound about each drive shaft 8, the first element 13 being contained within the chamber 2 and the second element 14 being located outside the chamber. The flexible elements may be cables, chains, lines, ropes etc., and are wound in opposite directions on the drive shaft such that one element unwinds from the shaft as the other winds onto the shaft. It will be appreciated that the two flexible elements could be joined together where they share a common point of attachment to the drive shaft.

As shown in Fig. 3, each chamber 2 contains a buoyancy vessel 16 which can move up-and-down within the chamber 2. The buoyancy vessel is open at its bottom end 16a and is provided with an air escape valve 17 at its top end. Beneath the buoyancy vessel 16 an air manifold 18 is fixed within the chamber supplied with air from a branch 19 of the air pipe 4 via an inlet control valve 20 (e.g. solenoid-operated) and a non-return valve 21. An air transfer pipe 22 passes through the top of the air manifold with its bottom end terminating within the manifold. When the buoyancy vessel 16 is in the position shown, the top of the transfer pipe 22 -6 -passes into the buoyancy vessel through the open end 16a. The bottom end 23 of the manifold 18 may be open allowing the first flexible element 13 to pass into the air manifold 18 and travel upwards through the air transfer pipe before being tethered to the buoyancy vessel 16 by a cross-pin 24. As can be seen in the external view of Fig. 4 and the ghost views of Figs 5 and 6, the second flexible element 14 is wound on the portion of the drive shaft 8 which projects outside the chamber 2 and travels upwards alongside the chamber until it reaches the top of the chamber where the element passes over a pulley 25. The flexible element 14 then enters a guide tube 26 where the element is fixed to a counterweight (not shown) which can slide up-and-down under gravity within the guide tube 26.

In use, each of the chambers 2 is filled with water up to a level 27, as indicated in Fig. 6. The buoyancy vessel 16 may be guided within the chamber 2 by spaced runners 29 which allow water to flow between them. Similarly, as shown in Fig. 5, apertured supports 30 may be provided for the air manifold 18, which also allow water to flow beneath the manifold. Air is fed under pressure through the branch pipe 19 so that the manifold 18 starts to fill with air. The water level in the manifold 18 falls to a level 28 (Fig. 3) and air travels up through the transfer pipe 22 displacing water from the buoyancy vessel 16. As its buoyancy increases due to the air entry the buoyancy vessel rises through the water causing the first flexible element 13 to unwind making the drive shaft 8 rotate, which in turn imparts torque to the output shaft 5. At the same time, rotation of the drive shaft 8 causes the -7 -counter-wound second element 14 to wind onto the drive shaft which in turn raises the counterweight within the guide tube 26. When the buoyancy vessel 16 reaches the water surface 27 in the chamber 2, air exits through the escape valve 17 so that the vessel re-fills with water until the buoyancy falls sufficiently to allow the vessel to sink back towards the starting position shown. Such return is assisted by the action of the counterweight within the guide tube 26 which causes the rotation of the drive shaft 8 to reverse and re-winds the first flexible element onto the drive shaft. The one-way bearings 12a and/or 12b (Fig. 2) ensure that the reverse rotation does not produce reverse torque on the output shaft 5. These bearings also act such that torque is only applied to the output shaft when the buoyancy of the vessel 16 is sufficient to exceed the rotational speed of the output shaft 5.

In its simplest form the apparatus could comprise a single chamber 2, but by providing multiple chambers the torque on the output shaft can be increased considerably. Furthermore, by using an electronic or mechanical control system to time the opening of the inlet control valves 20 (Fig. 3) the filling of the manifolds can be operated sequentially to ensure that a substantially smooth and continuous torque is produced.

Although the water chambers 2 may have a separate watertight casings it is possible for multiple chambers to be interconnected. Indeed, multiple chambers 2 may be provided within a single common watertight casing which contains multiple buoyancy vessels 16 along with their associated components. -8 -

The number and volume of the liquid chambers 2 and the type of air supply used is determined by the depth of water and the air pressure and flow required to create the required output torque.

In its simplest form the escape valve 17 could be a small hole which allows air to escape from the buoyancy vessel 16 at a controlled rate, but a valve which only opens when the buoyancy vessel reaches the water surface is preferable. A simple ball valve or a float-operated valve may be used.

In most cases a starter 7 will not be necessary although it might be useful in dry simulations for example.

Although the above example describes an air and water system it will be appreciated that any gas could be used with any liquid which provides sufficient buoyancy.

Whilst the above description places emphasis on the areas which are believed to be new and addresses specific problems which have been identified, it is intended that the features disclosed herein may be used in any combination which is capable of providing a new and useful advance in the art. -9 -

Claims

CLAIMS1. Apparatus for converting buoyancy forces of a gas in a liquid into mechanical torque: - a liquid chamber (2), - a gas manifold (18) in the liquid chamber, - a gas supply (3) for the gas manifold, - a buoyancy vessel (16) movable in the liquid chamber and arranged to receive gas from the gas manifold, - a rotatable member (8), - a first flexible element (13) wound about the rotatable member (8) and tethered to said buoyancy vessel (16) such that the buoyancy vessel rotates the rotatable member, - a return arrangement (14, 25, 26) to rotate the rotatable member (8) in an opposite sense to the buoyancy vessel (16) such as to rewind the first flexible element (13) onto the rotatable member (8).
2. Apparatus according to claim 1 wherein the return arrangement includes a second flexible element (14) which is wound about the rotatable member (8) in an opposite sense to the first flexible element (13).
3. Apparatus according to claim 2 wherein the second flexible element (14) is connected to a counterweight arrangement (26).
-10 - 4. Apparatus according to any preceding claim wherein the buoyancy vessel (16) includes an escape valve (17) to release gas therefrom.
5. Apparatus according to any preceding claim wherein an output shaft (5) is coupled to the rotatable member (8) via a one-way clutch arrangement (12a, 12b).
6. Apparatus according to claim 5 wherein a plurality of such liquid chambers (2) have their respective rotatable members (8) coupled to the output shaft (5).
7. Apparatus according to claim 6 wherein said plurality of liquid chambers (2) are mutually interconnected.
8. Apparatus according to any of claims 5 to 7 wherein the output shaft drives an electricity generator (6).