GB2501690A - Gravity heat engine with rotary valve - Google Patents

Abstract

A gravity engine 10 has at least two identical drums 12, 14 attached to a horizontal shaft 20 rotatably supported by a frame 22, 24. A sequence valve 32 controls a sequence of liquid movements between the drums 12, 14, a boiler 30 and a condenser 28. In a first range of angular movement, the boiler 30 is attached to whatever drum 12, 14 is lower and the condenser 28 is coupled to whatever drum is higher for the boiler 30 pressure to force transfer of liquid to the higher drum. The weight of liquid in the higher drum 12, 14 causes, during a second range of angular movement, rotation of the shaft 20. The resulting rotary motion may be coupled to rotate electrical generators, irrigation wheels or pumps. The boiler can be heated by ground heat, direct solar heat, solar panels and burning waste materials. The condenser can employ water cooling, heat radiation cooling, convection in air and cooling by contact with soil.

Description

Gravity Engine Apparatus and Method The present invention relates to a heat engine where a working substance is put though a temperature cycle between high and low temperatures and employed to provide mechanical movement.

Various heat engines employing working substances are known. A prime example is to be found in steam engines where a high temperature and high pressure steam is created in a boiler and repeatedly employed to push upon a piston to impart mechanical work before the steam is discarded through a condenser. Usually, in a steam engine, working in an open cycle, the working substance, the steam, is discarded after expansion into the atmosphere. In the present invention the working substance is sent to a condenser to be returned to the boiler, thereby conserving materials.

Heat engines, of which steam engines are an example, but which can also be said to include internal combustion engines of all kinds, employ piston pressure to generate mechanical energy. Pistons and their associated crankshafts and gearboxes cause wear and waste energy from the engine in the form of unnecessary mechanical losses. The present invention seeks to provide improvement over prior art solutions by eliminating pistons from energy provision.

A prior art gravity device is to be found in the so-called "nodding bird" toys where a hollow toy figure resembling a bird is pivoted to rock upon a rest. A working substance is contained within the hollow figure. The figure has an upright position where a head portion is above the pivot and a tail portion is below the pivot. Local heat sources cause a working substance be displaced into the head portion from the tail portion for the figure to overbalance, the head portion and the tail portion rotating about the pivot under the force of gravity to assume a tilted position. This position causes the working substance to be cooled, and returned to the tail portion. The balance shifts again and the figure returns under gravity to the upright position. The "nodding bird" provides, as a novelty, reciprocating motion. Unfortunately, reciprocating motion on such a small scale is difficult to put to use. The present invention seeks to use a similar gravitational principle to the nodding bird, but to provide rotary motion instead of reciprocating motion and on a scale suitable for providing useful mechanical work and services.

Heat engines require a source of heat to provide heat to a boiler. The boiler temperature depends upon the nature of the working substance. The present invention seeks to provide an apparatus that can employ a variety of different working substances that require only a relatively low temperature heat source for the apparatus to function.

Prior art heat engines require complex valve gear having many moving parts, requiring adjustment and prone to failure. The present invention seeks to provide much simplified valve gear with only two moving parts and certain in its adjustment.

Heat sources require fuel. Fuel can be a scarce commodity in third world countries. The present invention seeks to provide a heat engine that can employ a variety of low cost fuels or even locally available environmentally available heat sources to function and provide mechanical work.

To summarize, the present invention seeks to provide a piston-less heat engine that has a self-contained working substance, that works from relatively low temperature heat sources that are cheap or cost effectively nothing to obtain, and is suitable and cheap enough for use in third world economies.

According to a first aspect, the present invention provides an apparatus for providing mechanical energy by employing a working substance repeatedly cycled between a boiler and a condenser, the apparatus comprising: a shaft supportable by a frame; at least two substantially identical drums, the drums each being supportable at a respective end of a respective radial arm to be spaced from the shaft at equal distances from the shaft in a circularly symmetric manner, the drums being free to rotate with rotation of the shaft and each drum comprising first and second taps; a liquid transfer tube coupled to the taps; and a sequence valve operable to couple the boiler, the condenser and the taps to execute a liquid exchange sequence between drums; where the sequence comprises: in a first range of angular movement, the sequence valve coupling boiler pressure to whichever drum is lower and coupling the condenser to whichever drum is higher to cause liquid to be transferred from the lower to the upper drum through a liquid transfer tube; and in a second range of angular movement allowing the previously higher drum to fall under the weight of liquid to turn the shaft and to become the lower drum for repeating the first range of angular movement.

According to a second aspect, the present invention provides a method for providing mechanical energy by employing a working substance repeatedly cycled between a boiler and a condenser, the method comprising: a step of supporting a shaft in a frame; a step of providing at least two substantially identical drums, and supporting the drums each at a respective end of a respective radial arm spaced from the shaft at equal distances from the shaft in a circularly symmetric manner, the drums being free to rotate with rotation of the shaft and each drum comprising first and second taps; a step of transferring liquid between drums; and a step of employing a sequence valve to provide sequentially executed connections between the boiler, the condenser and the taps to execute a liquid exchange sequence between drums; where the sequence comprises: a step of, in a first range of angular movement, coupling boiler pressure to whichever drum is lower and coupling the condenser to whichever drum is higher to cause liquid to be transferred from the lower to the upper drum through a liquid transfer tube; and a step of, in a second range of angular movement, allowing the previously higher drum to fall under the weight of liquid to turn the shaft and to become the lower drum for repeating the first range of angular movement.

According to a third aspect, the present invention provides a sequence valve for use in a heat engine, the sequence valve comprising; an inner member and an outer sleeve, the inner member being slideably contained within the outer sleeve; the inner member comprising; a plurality of longitudinal passages adapted to allow through passage of liquid; and flow holes allowing liquid movement from a longitudinal passage to the outer surface of the inner member; the outer sleeve comprising: a plurality of closed circular passages each contained within the outer sleeve and of defined angular extent; where the outer sleeve allows liquid passage between bridged flow holes when the outer sleeve rotates relatively to the inner member.

The invention also provides that the sum of the first and second angular ranges can be 180 degrees and that the first angular range can be 120 degrees and the second angular range can be 60 degrees.

The invention also provides that the shaft can be coupled to rotate at least one of; an electrical generator; an irrigation wheel; and a pump.

The invention also provides that the boiler can be heated by at least one of: ground heat; direct solar heat; solar panels; and burning waste materials.

The invention also provides that the condenser can employ at least one of: water cooling; heat radiation coaling; convection in air; and cooling by contact with soil.

The invention also provides that the sequence valve can comprise; an inner member and an outer sleeve, the inner member being slideably contained within the outer sleeve; the inner member can comprise; a plurality of longitudinal passages adapted to allow through passage of liquid; and flow holes allowing liquid movement from a longitudinal passage to the outer surface of the inner member; where the outer sleeve can comprise: a plurality of closed circular passages each contained within the outer sleeve and of defined angular extent; and where the outer sleeve can allow liquid passage between bridged flow holes when the outer sleeve rotates relatively to the inner member.

The invention also provides for use of a plurality of rotary seals each operable to prevent The invention is further explained, by way of example, by the following description, to be read in conjunction with the appended drawings, in which: Figure 1 shows an isometric view of an exemplary gravity engine according to the invention.

Figure 2, shows in schematic form, the various element of the gravity engine Figures 3A and 3B show, in schematic form, connections involved in operation of the gravity engine when it performs a full rotation (in a clockwise direction as seen in Figure 1 and 2) between first, second, third and fourth positions. and

Figures 4A to 4C show assembly and internal details if the sequence valve Attention is first drawn to Figure 1, showing an isometric view of an exemplary gravity engine according to the invention.

Fig. 1 shows the essential components of a gravity engine 10. It consists of first 12 and second 14 cylindrical drums, supported by a radial arm 16. The drums 12 14 rotate in a single direction, as indicated by exemplary arrow 18 about a main horizontal shaft 20 suitably supported in three bearings between a first support frame 22 and a second support frame 24. At one end of the shaft 20, in this example, an electric generator 26 is connected, if necessary through an elliptic gearing, to provide correct speed of rotation for the generator. The shaft 20 also carries the rotary seal connections (not shown in Figure 1) to the stationery condenser 28 and boiler 30. The shaft also carries the sequence valve 32, to provide the cyclical connections as described later.

Attention is next drawn to Figure 2, showing in schematic form, the various elements of the gravity engine 10.

The first 12 and second 14 drums are supported by their respective portions of the radial arm 16 that terminate on the sequence valve 32. The condenser 28 and the boiler 30 are also coupled to the drums 12 14 through the sequence valve 32. A liquid transfers tube 34 is provided, supported and located appropriately, having a first end 36 and a second end 36a, selectably connectable to the taps 38 -44 on the drums 12 14 tube 34 through the sequence valve 32 to transfer liquid between the drums. The first drum 12 has a first drum first tap 38 and a first drum second tap 40 by which liquid can be moved to and from the first drum 12 when the sequence valve 32 so connects. The second drum 14 has a second drum first tap 42 and a second drum second tap 44 by which liquid can be moved to and from the second drum 14 when the sequence valve 32 so connects. The above connections are shown schematically in the Figure as external pipe connections to show the liquid transfer, but the flow path is actually realized though the connections made by the sequence valve 32.

Attention is next drawn to Figures 3A and 3B showing, in schematic form, connections involved in operation of the gravity engine 10 when it performs a full rotation (in a clockwise direction as seen in Figure 1 and 2) between first, second, third and fourth positions. In Figure 3A and 3B the angle Al is 120 degrees and the angle A2 is sixty degrees. Position 2 is 120 degrees clockwise from Position 1, position 3 sixty degrees clockwise from position 2. Position 4 is sixty degrees clockwise from position 3. Position 1 S is returned to by a further 120 degree clockwise rotation.

Attention is also drawn to Table 1 that lists the manner in which the connections are made and the angles of movement during which the connections are made.

Tapping AngleOtol2O Anglel2Oto Anglel8Oto Angle300to degrees 180 degrees 300 degrees 360 degrees First drum Liquid transfer closed Condenser 28 closed first tap 38 tube end 36 First drum boiler 30 closed Liquid transfer closed second tap tube end 36 Second drum Condenser 28 closed Liquid transfer closed first tap 42 tube end 36 a Second Drum Liquid transfer closed boiler 30 closed second tap tube end 44 36a Liquid transfer First drum closed first drum closed tube end 36 first tap second tap 38 40 Liquid transfer Second drum closed Second drum closed tube end 36a second tap first tap 44 42 Table 1: Connections for different amounts of Gravity Engine rotation.

The drums 12 14, liquid transfer tube 34, the liquid transfer tube ends 36 36a, taps 38-44, condenser 28 and boiler 30 are connected as indicated in Table 1. As shown in Figures 3A and 3B the above sequence of connections causes always one of the drums 12 14 to weighted with liquid at the upper end of the radial arm 16 while on the opposite side of the shaft 20 the other drum 14 12 to be substantially empty of liquid. The weight difference between the two drums 14 12 causes the gravity engine 10 to rotate for much the same reason that an overshot waterwheel rotates, the greater weight of liquid at a height allowing gravitational force to turn the drums 12 14 about the shaft 20.

In operation, higher pressure vapour from the boiler 30 is connected to the drum 12 14 at the lower level, while the gravity engine 10 moving parts are negotiating degrees of motion. Simultaneously, the upper drum 14 12 is connected to the lower condenser 28 pressure. This causes liquid to be transferred from lower to the upper drum 12 14.

This is illustrated in Fig.3A. The connection to the boiler 30 and condenser 28 is cut off, when drums 12 14 reach Position 2. The drums 12 14 then rotate to position 3 as shown in Figure 3B. The sequence of operations are then repeated with the drums, the lower one occupying the upper position, and vice versa. The torque changes as the drums rotate from positions (1) to (4), completing a full cycle.

The torque generated during the positions 2 to 3 and during positions 4 to I is given by TA = 2m0gRcos (150-.) (1) where * is the angle measured from position 1 shown in Figure 3A m0 mass of liquid transferred from lower to upper chamber during position Ito II R Effective radius of chambers on the shaft 20 g Acceleration due to gravity The torque during position ito 2 is proximately given by TBnTIO gR(e /60) eos(150-8) for8>60...(2) T11=mo gR(0 /60) cos(30-{-0) forO<60 Note that "changes from 180 to 300 O for position 3 to 4 The torque during position 3 to 4 is proximately given by T = rn0 g R ((0-180) /60) cos (0-150) for 0<240.. (3) T = m0 g R ((0-180) /60) cos (330-0) for 0> 240 Attention is next drawn to Figures 4A, 4B and 4C showing respectively, in figure 4A, the sequence valve 32 dis-assembled into two parts, in Figure 4B the assembled sequence valve 32, and in Figure 4C a split view showing details of the interior of the outer sleeve of the sequence valve 32.

In figure 4A are shown a sequence valve 32 inner member 46 that fits into a sequence valve 32 outer sleeve 48. The inner member 46 comprises longitudinal passages 50 that allow each of the liquid transfer pipe 34 ends 36a 36, drum 12 14 taps 34-44, condenser 28 and boiler 30 to provide separate connection and flow for each. The longitudinal passages 50 are connected with flow holes 52 that connect with respective longitudinal passages 50 to make the connections required by Table 1 when portions within the outer sleeve 48 permit flow. The interior of the outer sleeve 48 comprises one or more rotary seals 54 to prevent leakage.

Figure 4B shows the inner member 46 assembled into the outer sleeve 48.

Figure 4C shows the outer shell 48 as it would appear if cut along a vertical plane and cut along a horizontal plane (as seen in Figure 4A) and the halves separated longitudinally to reveal internal detail. Closed circular passages 56 permit flow between flow holes 52 when two flow holes 52 are circularly bridged by a circular passage 56.

It is to be understood that stationary boiler 30 and the stationary condenser 28 are coupled to the rotary gravity engine 10 by means of further rotary seals 54 The main advantages of the gravity engine 10 are: a) That no sliding piston is used b) That It comprises a simple mechanical system requiring negligible maintenance c) That the thermodynamic principle used has a high thermal efficiency d) That the gravity engine can utilise temperature differential of several types of heat sources and heat sinks.

e) That no feed pump required for the boiler f) That the gravity engine can be exposed to ambient conditions, and is sufficiently rugged to withstand bad weather conditions. and

g) That the system is designed to avoid vapour locking The gravity engine, as described above, is based on "nodding bird" principle (also known as the drinking bird) that is here redesigned in a novel way such that a continuous rotation is achieved in place of oscillating motion.

Continuous rotary motion considerably facilitates the invention to be employed to connect devices for power output such as electric generators or pumps that will utilise mechanical power. The slow turning of the gravity engine 10 shaft 20 could be connected to a traditional electric generator requiring higher speed of rotation by using a suitable elliptic gear system. The slow rotary movement of the shaft of the gravity engine 10 could be ideal for use in slow irrigation. This gravity engine 10 can use several types of heat sources such as ground heat, solar heat directly or through use of solar panels, employing the heat of the Sun, or by burning of waste materials. The heart of the invention is in the use of a unique and novel rotating sequence valve. The sequence valve 32 automatically performs required flow connections and also provides a means of improving the operating efficiency. A flywheel device could also be coupled to the shaft 20 to improve rotational speed regularity and speed of change. Working substances having appropriate boiling and condensing temperatures can be used to suite the available temperatures of heat source and heat sink.

While the invention has been described with reference to use of only two drums 12 14, it is to be appreciated that a sequence valve 32 may be adapted to be used with any number of drums symmetrically arranged about the shaft on a circle of rotation without departing from the invention as claimed. The sum of the S first and second ranges of movement will be 360 degrees divided by the number of drums 12 14 and each first range of movement will be an appropriate fraction of the former.

The invention can be used not only for performing practical tasks, but is also applicable to use in toys and demonstration models of all kinds.

Those, skilled in the art, will be aware of other variants and modifications that can be applied without departing from the invention as defined in the claims given here below.

The invention is further clarified and defined by the appended Claims.

Claims (20)

1. Claims.1. An apparatus for providing mechanical energy by employing a working substance repeatedly cycled between a boiler and a condenser, the apparatus comprising: a shaft supportable by a frame; at least two substantially identical drums, the drums each being supportable at a respective end of a respective radial arm to be spaced from the shaft at equal distances from the shaft in a circularly symmetric manner, the drums being free to rotate with rotation of the shaft and each drum comprising first and second taps; a liquid transfer tube coupled to the taps; and a sequence valve operable to couple the boiler, the condenser and the taps to execute a liquid exchange sequence between drums; where the sequence comprises: in a first range of angular movement, the sequence valve coupling boiler pressure to whichever drum is lower and coupling the condenser to whichever drum is higher to cause liquid to be transferred from the lower to the upper drum through a liquid transfer tube; and in a second range of angular movement allowing the previously higher drum to fall under the weight of liquid to turn the shaft and to become the lower drum for repeating the first range of angular movement.
2. 2. The apparatus according to Claim 1 wherein the sum of the first and second angular ranges is 180 degrees.
3. 3. The apparatus according to Claim 2 wherein the first angular range is 120 degrees and the second angular range is 60 degrees.
4. 4. The apparatus according to any of the preceding claims wherein the shaft is coupled to rotate at least one of; an electrical generator; an irrigation wheel; and a pump.
5. 5. The apparatus, according to any of the preceding claims; wherein the boiler is heated by at least one of: ground heat; direct solar heat; solar panels; and burning waste materials.
6. 6. The apparatus, according to any of the preceding claims; wherein the condenser employs at least one of: water cooling; heat radiation cooling; convection in air; and cooling by contact with soil.
7. 7. The apparatus, according to any of the preceding claims; wherein the sequence valve comprises; an inner member and an outer sleeve, the inner member being slideably contained within the outer sleeve; the inner member comprising; a plurality of longitudinal passages adapted to allow through passage of liquid; and flow holes allowing liquid movement from a longitudinal passage to the outer surface of the inner member; the outer sleeve comprising: a plurality of closed circular passages each contained within the outer sleeve and of defined angular extent; where the outer sleeve allows liquid passage between bridged flow holes when the outer sleeve rotates relatively to the inner member.
8. 8. The apparatus, according to any of the preceding claims, comprising a plurality of rotary seals each operable to prevent working substance leakage.
9. 9. A method for providing mechanical energy by employing a working substance repeatedly cycled between a boiler and a condenser, the method comprising: a step of supporting a shaft in a frame; a step of providing two substantially identical drums, and supporting the drums each at a respective end of a respective radial arm spaced from the shaft at equal distances from the shaft in a circularly symmetric manner, the drums being free to rotate with rotation of the shaft and each drum comprising first and second taps; a step of transferring liquid between drums and a step of employing a sequence valve to provide sequentially executed connections between the boiler, the condenser and the taps to execute a liquid exchange sequence between drums; where the sequence comprises: a step of, in a first range of angular movement, coupling boiler pressure to whichever drum is lower and coupling the condenser to whichever drum is higher to cause liquid to be transferred from the lower to the upper drum through a liquid transfer tube; and a step of, in a second range of angular movement, allowing the previously higher drum to fall under the weight of liquid to turn the shaft and to become the lower drum for repeating the first range of angular movement.
10. 10. The method according to Claim 9 wherein the sum of the first and second angular ranges is 180 degrees.
11. 11. The method, according to Claim 10, wherein the first angular range is 120 degrees and the second angular range is 60 degrees.
12. 12. The method, according to any of claims 9 to 11 including a step of coupling the shaft to rotate at least one of; an electrical generator; an irrigation wheel; and a pump.
13. 13. The method, according to any of claims 9 to 12, including a step of heating the boiler by at least one of: ground heat; direct solar heat; solar panels; and burning waste materials.
14. 14. The method, according to any of claims 9 to 13, including a step of cooling the condenser by at least one: water cooling; heat radiation cooling; convection in air; and cooling by contact with soil.
15. 15. The method, according to any of claims 9 to 14; including the steps of; providing in the sequence valve an inner member and an outer sleeve, the inner member being slideably contained within the outer sleeve; providing in the inner member a plurality of longitudinal passages adapted to allow through passage of liquid; providing in the inner member flow holes allowing liquid movement from a longitudinal passage to the outer surface of the inner member; providing in the outer sleeve a plurality of closed circular passages each contained within the outer sleeve and of defined angular extent; and allowing liquid passage between bridged flow holes when the outer sleeve rotates relatively to the inner member.
16. 16. The method, according to any of claims 9 to 15, including employing a plurality of rotary seals each to prevent working substance leakage.
17. 17. A sequence valve for use in a heat engine, the sequence valve comprising; an inner member and an outer sleeve, the inner member being slideably contained within the outer sleeve; the inner member comprising; a plurality of longitudinal passages adapted to allow through passage of liquid; and flow holes allowing liquid movement from a longitudinal passage to the outer surface of the inner member; the outer sleeve comprising: a plurality of closed circular passages each contained within the outer sleeve and of defined angular extent; where the outer sleeve allows liquid passage between bridged flow holes when the outer sleeve rotates relatively to the inner member.
18. 18. The apparatus, substantially as described with reference to the appended drawings.
19. 19. The method, substantially as described with reference to the appended drawings.S
20. 20. A sequence valve, substantially as described with reference to the appended drawings.