IL148883A - Liquid piston heat engine - Google Patents

Description

Liquid Piston Stirling Engine The present invention relates to the technical field of Gravitational Stirling engine - Stirling engine that uses the force of gravity.

Stirling engine, invented in 1816, is the subject of many research projects conducted today, both as energy source and as heat pump for refrigerators. The Stirling heat pump is a Freon free refrigerator that can eliminate the use of ozone depleting chlorofluorocarbons (CFC).

The Stirling engine is environment friendly. The engine may use natural heat sources such as solar energy or geothermal energy.

One of the problems facing Stirling engine designers is the sealing of the engine pistons. The methods used to solve the problem are complicated and expansive. As result, engine's production and maintenance are expensive. One of the methods to solve the sealing problem is the use of liquid piston.

Liquid pistons are used in the prior art. The following is a list of patents that defines heat engines that uses liquid: US5899067 is a "hot liquid" heat engine that implement a cycle similar to Stirling cycle that uses Hot Liquid instead of Hot Air. The engine uses metal pistons, fixed cylinders and operates against gravity.

US5022229 is a cryoco^^ operates against gravity.

US4148195 is a heat pump that uses fixed cylinders and liquid pistons. Unlike the current invention, the pistons are moving against gravity.

US424583 is a Double acting, Alpha type Stirling engine that uses fix cylinders and metal pistons.

US5195321 is a "Liquid piston heat engine". The engine is not a Stirling engine, needs an electrical engine to start its operation (unlike Stirling engines that are self-starting). The engine uses two degenerate Stirling engine (doesn't produce power), named Fluidyne and used as pump, to accelerate the engine rotation, by changing the mass center of the engine. The engine uses fixed cylinders and operates against gravity.

Stirling engine with Liquid pistons implementation has two problems: 1. Liquid pistons weight is not balanced by each other unlike metal pistons that are balanced by the use of crankshafts. As result, liquid piston moves against gravity. 2. The transfer of the engine energy into rotational flywheel pivot is complex without the use of crankshafts.

The present invention solves the 1st problems by the use double acting liquid pistons and moving cylinders: The internal pressure difference between the hot cylinder and the cold cylinder is used to move the liquid pistons inside the cylinders. The cylinders are out of balance and moves by Gravity. The cylinder movement is translated to the rotation of a flywheel pivot.

Gravitation is the power source of the engine - the engine will not work without the present of gravitation.

The present invention uses close environment that maintain high pressure.

The engine can use high temperature by using liquid metal (mercury) or melted metals in the hot cylinder.

Because of its simplicity and small number of component, very small engines can be implemented.

Double acting Stirling engines exists in the prior art as in United States Patent No. 4,524,583 or United States Patent No. 4,428,197. The embodiment of these engines uses metal pistons and suffers from sealing problems.

The significance of the present invention is the use of double acting liquid pistons. Two engines that form a closed system where the two hot cylinders are connected and share a double acting liquid piston and the two cold cylinders are connected and share a double acting liquid piston. The advantage of this simple embodiment is the combination of efficient liquid pistons with high pressure / high temperature engine.

In these aspects, the present invention is distinguished from and superior over the prior art.

The principle of operation of the present invention can be best understood by reference to a specific embodiment. In this embodiment the engine is constructed from two parallel pipes, shaped as rings that can rotate vertically on a central pivot. The rings rotation is limited to 90° in each direction.

Each ring-pipe is partially filled with liquid to a level that enables the liquid to function as an efficient piston that divides the pipe into two cylinders. Two flexible pipes connect the two rings. Before connecting the rings, the rings are rotated in opposite direction to create a 90° phase shift between them. One flexible pipe connects the left side open ends of both rings. The second flexible pipe connects the right side open ends of both rings. The two flexible pipes are tightly attached to each other, to enable optimal heat exchange between them.

The two rings are synchronized by a gear mechanism that maintains a constant bi-directional rotation between the rings. < The gear is also used to transfer the power generated by the bi-directional rotation of both rings into a continuous rotation of a flywheel pivot.

One ring is externally heated and the second ring is externally cooled. The left side of the hot ring and the left side of the cold ring are two cylinders with liquid pistons that are connected by pipe that function as regenerator. The cylinders are synchronized to maintain a constant phase shift between them. By definition they are forming an Alpha type Stirling engine. It applies to the right side of both rings.

The result is a closed system composed of two Alpha type Stirling engines, with moveable cylinders, where the two hot cylinders are connected and shares a double acting liquid piston and the two cold cylinders are connected and shares a double acting liquid piston.

By definition, a phase shift of two Stirling Cycle's states exists between the two engines. For example, if one engine is in the Heating state, the other engine is in the Cooling state. As result, a temperature difference always exists between the two regenerator-pipes that connect the two engines. Since both pipes are attached, they function as efficient regenerator. The working gas pressure in the hot ring-pipe increases. Because of the phase shift, the pressure in one cylinder is grater then the other. The working gas push the liquid piston towered the other cylinder. The ring is out of balance and rotates to the opposite direction by Gravity. This is the heating state of Stirling cycle in one engine and the cooling state in the second engine.

These and further advantages of the invention will become more clearly understood in the light of the following description of a preferred embodiment of the invention, given by way of example only, with reference to the accompanying drawings, wherein: Fig. 1 is a perspective illustration of the ring-pipe engine.

Fig. 2 is a top view of the ring-pipe engine structure.

Fig. 3A - 3B illustrates the vertical section A-A in t e ring-pipe.

Fig. 4 illustrates a section in the regenerator pipes.

Fig. 5A - 5D illustrates the rings synchronization mechanism.

Fig. 6 " is a 3D illustration of the synchronization mechanism.

Fig. 7 illustrates the Stirling Cycles of the two Ring-Pipe engines, relative to the synchronization gearwheels of Fig. 5B.

Referring to Fig. 1 the ring-pipe engine includes two ring-pipes, 1 and 2, with rectangular shaped section, that rotates on two separate pipes that function as pivots 4.

Ring-pipe 1 function as the hot side of the engine and ring 2 is the cold side of the engine. Ring pipe 1 is positioned in phase shift of 90° relative to ring-pipe 2. Each ring-pipe is divided by the partition 6. The two rings are half filled with liquid that function as pistons and divide each ring to two cylinders. Each cylinder has an opening 7 that enables the working gas to move between hot and cold rings, using the flexible pipes 21. The flexible pipes 21 are attached together and function as regenerator.

Flywheel 5 is connected to Pivot 3 that rotates inside said pipes pivots 4. Pivot 3 and flywheel 5 are part of the synchronization device that resides between the ring-pipes.

Fig 2. is a top view of the engine.

Synchronization device 40 connects and synchronizes ring pipe 1 and ring pipe 2. AA and BB are sections in the hot ring pipe 1 and the cold ring pipe 2.

Fig. 3A illustrates the section AA defined in Fig 2.

To simplify the engine construction, the ring-pipe is build from an external pipe 23 and an internal pipe 24 soldered to circular walls. The rectangular partition 6 is soldered to the pipes and walls of the ring-pipe. The liquid 25 that half fill the ring-pipe function as double-acting piston for both cylinders (21 ,22). Each cylinder has a connector 7 that enables the working gas transfer, using pipes 21.

Fig. 3B illustrates the pivot of each ring-pipe.

The pivot is built from two separated pivots. Pivot 4 is a pipe that functions as the pivot of the ring-pipe. The ring-pipe rotates around Pipe 4, using the bearing 30.

Pivot 3 transfers the engine power to the flying wheel. Pivot 3 rotates inside pipe 4, using the bearing 31.

Fig. 4 illustrates a section in the regenerator pipes 21.

The section of pipes 21 reveals two flexible pipes, 210 and 211, with heat conduction capacity and optimized contact surface 212, enclosed within isolation tube.

Fig 5 illustrates the synchronization device The synchronization device is located between ring-pipe 1 and ring-pipe 2. The synchronization device purpose is: - To maintain a constant phase shift between the hot and cold cylinders; - To transfer the power generated by the ring-pipe back and forth movement into a continuous rotational movement of a flywheel pivot 3; The power generated by the ring pipes is transferred by gearwheel 8, concentric and soldered to the hot ring-pipe 1.

Gear 19 is concentric and soldered to the cold ring-pipe.

Pivot 9 and the gear wheels 11 , 16, 17 and 12 are responsible to capture and transfer the clockwise movement of the gear 8, and to synchronize the movement of the second ring pipe 2, using gearwheel 19, concentric and soldered to the hot ring-pipe 2.

Pivot 10 and the gear wheels 13, 15 and 14 are responsible to capture and transfer the counter clockwise movement of the gear 8 and to synchronize the movement of ring pipe 2.

Gearwheel 11 captures the clockwise movement of gear 8 and gear 13 capture the counter clockwise movement of gear 8.

In order to capture the movement, gears 11 and 13 have tooth only on 180° section of their circumference." To keep the movement of gears 11 " and 13 when they are not in gear with 8, gear 15 and 16 are always in gear.

Gear 12 transfers the clockwise movement to gear 19 and gear 14 transfers the counter clockwise movement to gear 19.

In order to transfer the movement, gears 12 and 14 have tooth only on 180° section of their circumference.

In order to maintain the 90° phase shift between ring-pipe 1 and ring-pipe 2, gear wheel 12 has a 90° phase shift relative to gear wheel 11 and gear wheel 14 has a 90° phase shift relative to gear wheel 3.

Gear 17 transfers pivot 9 continues rotation to gear 18 that is attached to the flywheel pivot. 3.

Fig. 7 illustrates the relation between the Stirling cycle of both ring-pipe engines and the synchronization gears position (rows A B C and D).

Column AA displays the synchronization gear 11 and 13 as they appear at vertical section A-A in the hot ring-pipe. Column BB displays the synchronization gear 12 and 14 as they appear at vertical section B-B in the cold cylinders ring-pipe in Fig 2.

There are two Stirling engines in each row: The first engine is composed of the left cylinder in column AA and the left cylinder in column BB.

The second engine is composed of the right cylinder in column AA and the right cylinder in column BB.

It will be now readily comprehended that the arrangement according to the present invention constitutes a simple method to construct a Stirling engine with minimal, not expansive components, yet achieve.a high pressure, high temperature and powerful Stirling engine.

It will be also appreciated that many modifications and variations of the invention may be applied without departing from the scope thereof, as defined in and by the appended claims.

Claims (1)

What is claimed is:

1. A gravitational Stirling engine having a double acting liquid pistons and moving cylinders, comprising: a. liquid; b. the presence of gravitation or artificial gravitation force; c. two open pipes, partially filled with said liquid to a level that enable the liquid to function as an efficient piston that divides each said pipes into two cylinders; d. said pipes, vertically connected to a central pivot, and moveable within limits by gravity when said liquid piston moves inside them by changes in the gas pressure captured within the said cylinders; e. regenerator comprising tow pipes with good thermal conductivity attached with maximal shared surface and thermally isolated from the external environment; f. means to connect one said regenerator pipe to the left open end of said hot pipe and to the left open end of said cold pipe and means to connect second said regenerator pipe to the right open end of the hot,said pipe and to the right open end of the cold said pipe g. means for heating the first said pipe and cooling the second said pipe; h. a cycle defined for the hot pipe as the movement of the pipe back and forth to the extent of its said limits; i. a cycle defined for the cold pipe as the movement of the pipe back and forth to the extent of its said limits; j. means to synchronize the bi-directional movements of the hot pipe and the cold pipe so that a constant phase shift exists between the said cycle of the hot pipe and the said cycle of the cold pipe; k. means to convert the said bi-directional movement of said pipes to a continuous rotation of a flywheel pivot, forming two closed systems that have a Stirling cycle heat engine design, where working gas is captured between the double acting liquid piston of the hot pipe and the double acting liquid piston of the cold pipe; said engine as claimed in claim 1 wherein said open pipes are shaped as ring-pipes with open ends, each vertically rotate able on an horizontal pivot in the range of ± 90°, each divided to two cylinders by a double acting liquid piston, said engine as claimed in claim 2 wherein said ring-pipe pivot is an open pipe. said engine as claimed in claim 3 with means to synchronize the bi-directional movement of said ring-pipes with a constant phase shift between the ring-pipes said cycles and with means to convert it to a continuous rotation of a flywheel pivot, comprising: a. a ring shaped gearwheel attached and concentric to the hot ring; b. a ring shaped gearwheel attached and concentric to the cold ring; c. a clockwise flywheel pivot concentric to both said ring-pipes, freely rotate able by two bearings attached to each said ring-pipe's open pipe pivot; d. a gearwheel attached to said flywheel pivot, position between the tow ring-pipes; e. a second clockwise pivot with 3 gearwheels attached to it: i. a partial gear wheel with tooth only on 180° section of his circumference, resides on the end of said clockwise pivot, in gear with said ring shaped gearwheel that is attached to hot ring-pipe; g ii. a second partial gear wheel with tooth only on 180° section of his circumference, resides on the other end of said clockwise pivot, with phase shift of 90° relative to the first gear wheel and in gear with said ring shaped gearwheel that is attached to cold ring- pipe; iii. a gearwheel position in the pivot center; f. a counter clockwise pivot with 4 gearwheels attached to it: i. a partial gear wheel with tooth only on 180° section of his circumference, resides on the end of said counter-clockwise pivot, in gear with said ring shaped gearwheel that is attached to hot ring-pipe; and with phase shift of 180° relative to the said partial gearwheel, attached to clockwise pivot; ii. a second partial gear wheel with tooth only on 180° section of his circumference, resides on the other end of said clockwise pivot, with phase shift of 90° relative to the first gear wheel and in gear with said , ring shaped gearwheel that is attached to cold ring- Pipe; iii. a third gearwheel reside on the pivot in gear with the gearwheel attached to the flywheel pivot; iv. a fourth gearwheel resides on the pivot center and in gear with said center gearwheel that resides on said clockwise pivot. A double acting, gravitational Stirling engine with moveable cylinders and liquid pistons substantially as hereinbefore described with reference to the accompanying drawings. Horenstein Amikam