Technical Area 

This invention is about stirling engine, which is an internal combustion engined heat machine known as hot air engine and converting the heat to mechanical motion. 

Invention in question is about stirling engine, having an accordion/bellows element with opening and closing feature, that is placed between the connecting rod and gas transmission pipe and moving in an expansion gap whether folding or stretching to achieve the radial motion without using the cylinder and the piston.

 Previous Technique 

Increasing world population, decreasing energy sources and developimg technology cause continuous increase in energy need, on the other hand cause global warming and environmental problems. If the disadvantages of stirling engine, which is an externally heated engine, are removed and produced with mass production, it will be a solution for increasing energy need and environmental problems. 

In stirling engines, the heat is supplied from an external source, so there is the opportunity to use many heat sources in a wide range, from fossil based fuels to solar energy. Theoretically, heat efficiency is high and needs less maintenance. 

In stirling engines, there does not exist sudden explosions and valves, there exists continuous combustion, sinusoidal pressure change in engine conversion, balanced inertial forces, so both noise and vibration are reduced.  

In partial loading, it has a better performance than high compreesion rated (over filled) gasoline engines. It has a wide range of velocity and proper rotating moment characteristics. Oil consumption is too low. It can be operated in very low pressure.  

In the stirling engines used with the present technique, sealing is the main problem. Low molecular weight of hydrogen makes it the best working gas. But, these small molecules require additional auxiliary systems and has preservation difficulties. These sytems may be simple as gas tubes or complex ones like gas generator. In any case, it creates additional weight, increase in cost and undesirable problems.  

In the stirling engines used with the present technique, an oiling process is carried out. This process arises extra costs.   

The Advantages of Our Invention: 

-         Sealing problem is completely removed.

-         Energy loss caused by the friction of the cylinder and the piston is removed.

-         There is no need for oiling.

-         Costs are minimized.

-         There is no need for special materials. And this causes the invention to be economical and low-cost.

-         It is possible to produce based on mass production.

-         It creates a point that, alternative energy is being reached by the individual user. 

To achieve the above mentioned objects, it has an accordion/bellows element with opening and closing feature, that is placed between the connecting rod and gas transmission pipe and moving in an expansion gap whether folding or stretching.   

To achieve the above mentioned objects, the point is obtaining the required linear motion by the hot working gas affecting the folding and/or stretching material.

 The Figures Describing Our Invention: 

Figure-1: Two-dimensional general view of stirling engine used in previous technique.  

Figure-2; Two-dimensional general view of stirling engine which is the subject of this invention. 

Figure-3; Three-dimensional view of the accordion/bellows element of the stirling engine, subject of the invention. 

Figure-4; Three-dimensional view of the accordion/bellows element placed over cooling plates, subject of the invention. 

Figure-5; Two-dimensional side and cross-section views of the accordion/bellows element, subject of the invention.

 Part Numbers: 

1-Crankshaft

2-Connecting rod

3-Gas transmission pipe

4-Working gas

5-Regenerator

6-Transmission gap

7-Heat source

8-Cooling plates

9-Accordion/bellows element

9.1- Expansion Area

9.2- Bottom base

9.3- Top base

9.4- Flexible surfaces

10-Piston

11-Cylinder

A-Hot application

B-Cold application 

Detailed Explanation of the Invention 

The invention is composed of the following parts, in terms of the parts common in present technique and our invention. It contains connecting rods (2), gas transmission pipe (3), transmission gap (6), cold applied (B) second piston (10), cylinder (11), regenerator (5) and cooling plates (8), working gas (4) is heated by a heat source (7) and expands, hot application (A) piston (10) is pushed in the cylinder (11) and transmits the linear motion along the connecting rod (2).

And our invention has an extra accordion/bellows element having opening and closing feature in the expansion gap (9.1) placed between the connecting rods (2) and gas transmission pipe (3) without using the cylinder (11) or piston (10) to achieve the required radial motion.

The accordion/bellows element (9) mentioned above contains a movable bottom base (9.2) and a fixed top base (9.3) and folding and/or stretching flexible surfaces (9.4) formed over the accordion/bellows element(9).

 Working principle of the system is as follows. Stirling engine works by heating an amount of working gas (4) (eg, air or gases like helium, hydrogen) in one region and cooling in another region in a closed area. When the gas is heated, its pressure increases as it is in a closed area and pushes the bottom plate (9.2) of the accordion/bellows element (9) and forms radial motion in the crank shaft (1).

 This heated working gas (4) is transmitted to cold application (B) accordion bellows element (9) through gas transmission pipe (3) and cools there. After cooling, it is ready again to be heated and expansion and this cycle goes on continuously.

Accordion bellows element (9) pushes the bottom base (9.2) forward when heated. When it is closed, it pumps the gas inside to the second bellows element (9). And when it is opened, it vacuums gas in the other bellows element (9). In this case, it does the job of the cylinder piston couple of the previous technique, and also sealing and friction problems are removed.  

SUMMARY

STIRLING ENGINE 

The invention is about stirling engines, in which the working gas (4) is expanded by heating with a heat source (4) and pushes the piston (10) in hot application (A) cylinder and the created linear motion is transmitted to crankshaft (1) by the connecting rods (2) through a gas transmission pipe (3), and containing a transmission gap (6), second cold application (B) piston (10) and cylinder (11), and it is about the accordion/bellows element (9) having the feature of opening and closing by stretching oand/or folding in an expansion gap (9.1) placed between the mentioned connecting rods (2) and gas transmission pipe (3) to achieve the required radial motion without using the cylinder (11) and piston (10).

Menderes Suludere
08/01/2008