GB2460300A

GB2460300A - Variable buoyancy drive

Info

Publication number: GB2460300A
Application number: GB0809849A
Authority: GB
Inventors: Neil Lindsay; Roland Primus
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-05-30
Filing date: 2008-05-30
Publication date: 2009-12-02
Also published as: GB0809849D0

Abstract

A drive, claimed to be suitable for an electricity generating system, comprises a body 12 with adjustable buoyancy so that it can sink and rise in a liquid. The body is provided with valves (14, 16, 18, figure 2) so that buoyancy can be adjusted by injecting air or admitting water. The body 12 drives a shaft 2 via an arm 10 and may use a one way ratchet to drive the shaft in only one direction.

Description

The present invention relates to a drive for an electricity generating system and an electricity generating system including such a drive.

With the environmental and political pressures to generate electricity in an efficient and clean manner, it is desirable to achieve alternative methods that do not involve burning of fossil fuels. It is known that gravity and associate buoyancy effects can be utilised to create an output being in the form of useful energy. The present invention provides an effective environmentally sound approach.

According to the present invention there is a drive for an electricity generating system, the drive comprising: -a body arranged to sink and ascend in a liquid; a drive shaft connected to the body; -means to optionally reduce and increase the buoyancy of the body; wherein movement of the body through the effect of gravity andlor buoyancy causes rotation of the drive shaft.

The significant advantage of this system is that the system is efficient wherein a high energy output is provided compared to the associated input. The shaft may drive any energy producing equipment utilising the effects of gravity acting on the body and subsequently the buoyancy effect associated with the increased buoyancy of the body thereby causes the body to rise. It is therefore apparent that energy can be removed from the system in both upward and downward motion of the body.

The body preferably comprises a cavity therein. The body may also comprise one or more inlets to the cavity, and the drive further comprises an arrangement to selectively enable access to the cavity through the inlet.

It will be appreciated that the one or more inlets enable the passage of gas andlor liquid therethrough such that in the sinking phase liquid enters into the body cavity and in the ascending phase gas enters into the body cavity.

An arm is preferably provided to extend between the shaft and the body. It will be appreciated that an increased length provides an increased torque in the shaft. The arm may be flexible and may comprise a flexible elongate member, such as a rope or chain and may function as a pendulum type arrangement.

The means to optionally reduce and increase the buoyancy of the body preferably comprises means to inject gas into the cavity.

The means to inject gas into the body cavity preferably includes a channel through which the gas is passed. The channel is beneficially located through or externally of the arm which extends between a shaft and the body. A means to supply compressed air such as a compressor is also beneficially provided to inject gas into the body, preferably via the channel or external pipework.

A plurality of bodies are preferably connected to the shaft. The effect of this is that as one body sinks, another body is ascending such that continuous rotation of the shaft is achieved. Drive of the shaft may optionally occur in a generally upward or downward movement.

The body is preferably connected to the shaft via a clutch arrangement, even more beneficially the clutch arrangement is an overrunning clutch. The effects of this are that once the shaft is being driven through, for example, the body ascending, the shaft may continue rotating whilst the body sinks.

The shaft preferably rotates about a plurality of bearing sets. The shaft is also beneficially arranged to drive a fly wheel, the fly wheel arranged to connect to a generator. The fly wheel may be a variable mass fly wheel. A control arrangement is preferably provided for control of the reduction and increase of the buoyancy of the body. Even more beneficially, the control arrangement controls at least one of the gas injection into the body cavity and fluid access into the body cavity. The control arrangement also may control the respective phase of a number of bodies causing rotation of the shaft.

The present invention will now be described by way of example only with reference to the accompanying drawings in which: Figure 1 is a schematic plan view of a device according to an exemplary embodiment of the present invention.

Figure 2 is a schematic side view of a device according to an exemplary embodiment of the present invention.

Figure 3 is a schematic representation of the movement of the body with respect to the shaft according to an exemplary embodiment of the present invention.

Figures 4a and b are schematic side views of the body/shaft interface according to an exemplary embodiment of the present invention.

Referring to Figure 1, there is a shaft 2 arranged to rotate on at least one bearing set 4. In its simplest form, the shaft may be connected to, for example, a fly wheel 6 which is then linked by a linking device 8 such as a belt, mechanical clutch, fluid coupling, spider coupling, chain, electrical clutch or electro-mechanical clutch to a generator. Alternatively the shaft 2 is used to directly drive a chosen device. The shaft 2 has a plurality of arms 10 mounted rotatably thereto, the end of each arm 10 comprising a body such as a float 12. It will be appreciated that the arms 10 and float 12 may have any dimensions as necessary, and can be on any scale, for example the arms 10 may extend between 30 and 50 metres in length, and the float may have a diameter of approximately 10 metres. The system may be initially supported in a body of fluid wherein the arms 10 lie generally parallel to the surface of the body of fluids. The floats 12 sit in the body of fluid ready for use. The arms are rotatably mounted to the shaft 2 via a clutch type mechanism wherein movement of the arm 10 in one direction causes corresponding rotation of the shaft however rotation of the arm 10 in the opposite direction has no effect on rotation of the shaft. This will be described in more detail subsequently. It will be appreciated that a large number of arms and/or floats 12 may be utilised to cause increasing rotation speed of the shaft 2 when in use.

Referring also to Figure 2, the float 12 comprises an inlet and non-return valve 14 for receiving air and an outlet including a valve 16 which may be selectively opened to enable fluid to flow into the float. The air inlet and non-return valve 14 and valve 16 are arranged such that the apparatus, when in use will allow the float 12 to sink under its weight when filled with fluid and subsequently to rise when the fluid is forced from the float 12. This is more clearly shown in Figure 3 which shows the cycle of a single float and arm when in use. In position 1, with reference to Figure 3, fluid is allowed to enter the float via valve 16 either by removal of the fluid from the float via inlet and non-return valve 14 or alternatively through corresponding opening of valve 18 thus enabling fluid to fill the float.

This accordingly increases the weight of the float and as such the float will sink thereby rotating the shaft 2. Energy can be then transferred from the rotation of the shaft 2 to perform useful work, On reaching position 2, gas is forced through inlet and non-return valve 14 into the float 12 and thus the liquid is forced out of the float 12 through one or both of valves 16, 18. This will decrease the speed of rotation of the float until position 3 is reached at which point the buoyancy effect of the float will be significant. Once the weight of the float is less than the weight of the liquid displaced through the liquid being expelled from the float, the rotation direction of the float 12 and thus the arm 10 will change arid the float 12 will therefore rise. On reaching approximately position 2 again, air will be withdrawn from the float 12 either by being sucked through inlet and non-return valve 14 or alternatively by opening one or both of valves 16, 18 thereby increasing the weight of the float 12 and thus slowing the speed of rotation of the float until position 1 again is reached. The cycle will then be repeated wherein the weight of the float 12 increases to greater than the weight of the liquid displaced and thus sinks thereby causing rotation of the arm 10 about the shaft 2. A blocking mechanism 19 may be provided to prevent over-rotation of the arms 10. Such blocking mechanism 19 would not conrmonly be used as the control system is programmed to ensure that liquid enters the float 12 as float rises in a controlled manner such that the arm 10 slows to a halt in the horizontal configuration.

Referring to Figure 4, an exemplary embodiment of the clutch mechanism is shown wherein a drive is provided on the shaft which includes a ratchet 22 (which could be replaced by any other electro/mechanical clutch arrangement for example) which is pivoted via pivot point 20 and biased to a closed configuration in which the ratchet locates with corresponding teeth on the shaft. A spring 24 may be provided to bias the ratchet in engagement with the teeth of the shaft. Such a system enables the shaft to rotate, in the embodiment indicated in Figure 4, in a clockwise direction. The control arrangement (not shown) which controls opening of valves 16, 18 and inlet 14 ensures that the plurality of arms 10 and floats 12 act in sequence such that rotation of the shaft 2 is continuous, and at least one arm 10 and float 12 is always providing a force on the shaft to cause rotation, whilst another arm 10/float 12 returns to the position ready for further activation. There is also the option of reversing the above process.

A second embodiment of the present invention relates to a shaft having a clutch arrangement as described above. The shaft is suspended and the body connected to the shaft via a flexible member such as a rope or chain, and when doing so will cause rotation of the shaft. Such an assembly has the appearance of a simple pendulum. Means must be provided to cause rotational movement of the body and again increasing and decreasing the buoyancy of the body via values and a compressor. As the body rotates, the shaft also rotates accordingly and thus the energy is transferred via a clutch arrangement to, for example, a fly wheel. Bodies may be provided on one or both sides of the shaft, and if a body is provided on both sides of the shaft, a pendulum effect can be achieved, as one body falls, the other body rises.

The present invention has been described by way of example only and appreciated by a person skilled in the art for variations and modifications may be made without departing from the scope of protection afforded by the appended claims.

Claims

Claims 1. A drive for an electricity generating system, the drive comprising: -a body arranged to sink and ascend in a liquid; -a drive shaft connected to the body; -means to optionally reduce and increase the buoyancy of the body; wherein movement of the body through the effect of gravity andlor buoyancy causes rotation of the drive shaft.
2. A drive according to claim 1 wherein the body comprises a cavity therein.
3. A drive according to claim 2 wherein the body comprises one or more inlets to the cavity, the drive further comprising an arrangement to selectably enable access to the cavity through the inlet.
4. A drive according to any preceding claim wherein the means to optionally reduce and increase the buoyancy of the body comprises means to inject gas into the cavity.
5. A device according to any preceding claim wherein an arm is provided to extend between the shaft and the body.
6. A device according to claim 4 and 5 wherein the means to inject gas into the body cavity includes a channel defined through the arm through which the gas is passed.
7. A device according to any preceding claim comprising a plurality of bodies connected to the shaft.
8. A device according to any preceding claim wherein the body is connected to the shaft via a clutch arrangement. 7..
9. A device according to claim 8 wherein the clutch arrangement is an overrunning clutch.
10. A device according to any preceding claim wherein the shaft rotates about a plurality of bearings.
11. A device according to any preceding claim wherein the shaft is arranged to drive a flywheel, the flywheel arranged to connect to a generator.
12. A device according to any preceding claim including a control arrangement for control of the reduction and increase of the buoyancy of the body.
13. A device according to claim 12 wherein the control arrangement controls gas injection into the body cavity and fluid access into the body cavity.
14. A device as hereinbefore described with reference to the accompanying drawings.