How to make a Stirling Displacer. How to make your own Stirling engine. Piece of hardwood or plywood

It replaced other types of power plants, however, work aimed at abandoning the use of these units suggests an imminent change in leading positions.

Since the beginning of technological progress, when the use of engines that burn fuel inside was just beginning, their superiority was not obvious. The steam engine, as a competitor, contains a lot of advantages: along with traction parameters, it is silent, omnivorous, easy to control and configure. But lightness, reliability and efficiency allowed the internal combustion engine to take over the steam.

Today, issues of ecology, economy and safety are at the forefront. This forces engineers to throw their forces on serial units operating on renewable fuel sources. In the year 16 of the nineteenth century, Robert Stirling registered an engine powered by external heat sources. Engineers believe that this unit is able to change the modern leader. The Stirling engine combines efficiency, reliability, runs quietly, on any fuel, this makes the product a player in the automotive market.

Robert Stirling (1790-1878):

Stirling engine history

Initially, the installation was developed with the aim of replacing the steam-powered machine. Boilers of steam mechanisms exploded, when exceeded allowable norms pressure. From this point of view, Stirling is much safer, functioning using a temperature difference.

The principle of operation of the Stirling engine is to alternately supply or remove heat from the substance on which work is performed. The substance itself is enclosed in a closed volume. The role of the working substance is performed by gases or liquids. There are substances that perform the role of two components, the gas is transformed into a liquid and vice versa. The liquid-piston Stirling engine has: small dimensions, powerful, generates high pressure.

The decrease and increase in the volume of gas during cooling or heating, respectively, is confirmed by the law of thermodynamics, according to which all components: the degree of heating, the amount of space occupied by the substance, the force acting per unit area, are related and described by the formula:

P*V=n*R*T

• P is the force of the gas in the engine per unit area;
• V is the quantitative value occupied by gas in the engine space;
• n is the molar amount of gas in the engine;
• R is the gas constant;
• T is the degree of gas heating in the engine K,

Stirling engine model:

Due to the unpretentiousness of the installations, the engines are divided into: solid fuel, liquid fuel, solar energy, chemical reaction and other types of heating.

Cycle

The Stirling external combustion engine uses a set of phenomena of the same name. The effect of the ongoing action in the mechanism is high. Thanks to this, it is possible to design an engine with good characteristics within normal dimensions.

It should be taken into account that the design of the mechanism provides for a heater, a refrigerator and a regenerator, a device for removing heat from the substance and returning heat at the right time.

Ideal Stirling cycle, (diagram "temperature-volume"):

Ideal circular phenomena:

• 1-2 Change linear dimensions substances with a constant temperature;
• 2-3 Removal of heat from the substance to the heat exchanger, the space occupied by the substance is constant;
• 3-4 Forced reduction of the space occupied by the substance, the temperature is constant, heat is removed to the cooler;
• 4-1 Forced increase in the temperature of the substance, the occupied space is constant, the heat is supplied from the heat exchanger.

The ideal Stirling cycle, (pressure-volume diagram):

From the calculation (mol) of a substance:

Heat input:

Heat received by the cooler:

The heat exchanger receives heat (process 2-3), the heat exchanger gives off heat (process 4-1):

R – Universal gas constant;

CV - the ability of an ideal gas to retain heat with a constant amount of space occupied.

Due to the use of a regenerator, part of the heat remains, as the energy of the mechanism, which does not change during the passing circular phenomena. The refrigerator receives less heat, so the heat exchanger saves the heat of the heater. This increases the efficiency of the installation.

Efficiency of circular phenomenon:

ɳ =

It is noteworthy that without a heat exchanger, the set of Stirling processes is feasible, but its efficiency will be much lower. Running the set of processes backwards leads to a description of the cooling mechanism. In this case, the presence of a regenerator, required condition, since when passing (3-2) it is impossible to heat the substance from the cooler, the temperature of which is much lower. It is also impossible to give heat to the heater (1-4), the temperature of which is higher.

The principle of the engine

In order to understand how the Stirling engine works, let's look at the device and the frequency of the phenomena of the unit. The mechanism converts the heat received from the heater located outside the product into a force on the body. The whole process occurs due to the temperature difference, in the working substance, which is in a closed circuit.

The principle of operation of the mechanism is based on expansion due to heat. Immediately prior to expansion, the substance in the closed circuit heats up. Accordingly, before being compressed, the substance is cooled. The cylinder itself (1) is wrapped in a water jacket (3), heat is supplied to the bottom. The piston that does the work (4) is placed in a sleeve and sealed with rings. Between the piston and the bottom there is a displacement mechanism (2), which has significant gaps and moves freely. The substance in a closed circuit moves through the volume of the chamber due to the displacer. The movement of matter is limited to two directions: the bottom of the piston, the bottom of the cylinder. The movement of the displacer is provided by a rod (5) which passes through the piston and is operated by an eccentric 90° late compared to the piston drive.

• Position "A":

The piston is located in the lowest position, the substance is cooled by the walls.

• Position "B":

The displacer occupies the upper position, moving, passes the substance through the end slots to the bottom, and cools itself. The piston is stationary.

• Position "C":

The substance receives heat, under the action of heat it increases in volume and raises the expander with the piston up. Work is done, after which the displacer sinks to the bottom, pushing out the substance and cooling.

• Position "D":

The piston goes down, compresses the cooled substance, useful work. The flywheel serves as an energy accumulator in the design.

The considered model is without a regenerator, so the efficiency of the mechanism is not high. The heat of the substance after work is removed into the coolant using the walls. The temperature does not have time to decrease by the required amount, so the cooling time is extended, the motor speed is low.

Types of engines

Structurally, there are several options using the Stirling principle, the main types are:

The design uses two different pistons placed in different contours. The first circuit is used for heating, the second circuit is used for cooling. Accordingly, each piston has its own regenerator (hot and cold). The device has a good power to volume ratio. The disadvantage is that the temperature of the hot regenerator creates design difficulties.

• Engine "β - Stirling":

The design uses one closed circuit, with different temperatures at the ends (cold, hot). A piston with a displacer is located in the cavity. The displacer divides the space into cold and hot zones. The exchange of cold and heat occurs by pumping a substance through a heat exchanger. Structurally, the heat exchanger is made in two versions: external, combined with a displacer.

• Engine "γ - Stirling":

The piston mechanism provides for the use of two closed circuits: cold and with a displacer. Power is taken off a cold piston. The displacer piston is hot on one side and cold on the other. The heat exchanger is located both inside and outside the structure.

Some power plants are not similar to the main types of engines:

• Rotary Stirling engine.

Structurally, the invention with two rotors on the shaft. The part performs rotational movements in a closed cylindrical space. A synergistic approach to the implementation of the cycle has been laid. The body contains radial slots. Blades with a certain profile are inserted into the recesses. The plates are put on the rotor and can move along the axis when the mechanism rotates. All the details create changing volumes with phenomena taking place in them. The volumes of the various rotors are connected by channels. Channel arrangements are offset by 90° to each other. The shift of the rotors relative to each other is 180°.

• Thermoacoustic Stirling engine.

The engine uses acoustic resonance to carry out processes. The principle is based on the movement of matter between a hot and a cold cavity. The circuit reduces the number of moving parts, the difficulty in removing the received power and maintaining resonance. The design refers to the free-piston type of motor.

DIY Stirling engine

Today, quite often in the online store you can find souvenirs made in the form of the engine in question. Structurally and technologically, the mechanisms are quite simple; if desired, the Stirling engine is easy to construct with your own hands from improvised means. On the Internet you can find a large number of materials: videos, drawings, calculations and other information on this topic.

Low temperature Stirling engine:

• Consider the simplest version of the wave engine, for which you will need a tin can, soft polyurethane foam, a disk, bolts and paper clips. All these materials are easy to find at home, it remains to perform the following steps:
• Take a soft polyurethane foam, cut two millimeters smaller diameter from the inner diameter tin can circle. The height of the foam is two millimeters more than half the height of the can. Foam rubber plays the role of a displacer in the engine;
• Take the lid of the jar, make a hole in the middle, two millimeters in diameter. Solder a hollow rod to the hole, which will act as a guide for the engine connecting rod;
• Take a circle cut out of foam, insert a screw into the middle of the circle and lock it on both sides. Solder a pre-straightened paperclip to the washer;
• Drill a hole two centimeters from the center, three millimeters in diameter, thread the displacer through the central hole of the lid, solder the lid to the jar;
• Make a small cylinder out of tin, one and a half centimeters in diameter, solder it to the lid of the can in such a way that the side hole of the lid is clearly centered inside the engine cylinder;
• Make an engine crankshaft out of a paper clip. The calculation is carried out in such a way that the spacing of the knees is 90 °;
• Make a stand for the crankshaft of the engine. From a plastic film, make an elastic membrane, put the film on the cylinder, push it through, fix it;

• Make an engine connecting rod yourself, bend one end of the straightened product in the shape of a circle, insert the other end into a piece of eraser. The length is adjusted in such a way that at the lowest point of the shaft the membrane is retracted, at the extreme upper point, the membrane is maximally extended. Adjust the other connecting rod in the same way;
• Glue the engine connecting rod with a rubber tip to the membrane. Mount the connecting rod without a rubber tip on the displacer;
• Put a flywheel from the disk on the crank mechanism of the engine. Attach legs to the jar so as not to hold the product in your hands. The height of the legs allows you to place a candle under the jar.

After we managed to make a Stirling engine at home, the engine is started. To do this, a lit candle is placed under the jar, and after the jar has warmed up, they give impetus to the flywheel.

The considered installation option can be quickly assembled at home, as a visual aid. If you set a goal and a desire to make the Stirling engine as close as possible to factory counterparts, there are drawings of all the details in the public domain. Stepping through each node will allow you to create a working layout that is no worse than commercial versions.

Advantages

The Stirling engine has the following advantages:

• A temperature difference is necessary for the operation of the engine, which fuel causes heating is not important;
• There is no need to use attachments and auxiliary equipment, the engine design is simple and reliable;
• The resource of the engine, due to the design features, is 100,000 hours of operation;
• The operation of the engine does not create extraneous noise, since there is no detonation;
• The process of engine operation is not accompanied by the emission of waste substances;
• Engine operation is accompanied by minimal vibration;
• Processes in the plant cylinders are environmentally friendly. Using the right heat source keeps the engine clean.

Flaws

The disadvantages of the Stirling engine include:

• It is difficult to establish mass production, since the engine design requires the use of a large amount of materials;
• High weight and large dimensions of the engine, since a large radiator must be used for effective cooling;
• To increase efficiency, the engine is boosted using complex substances (hydrogen, helium) as a working fluid, which makes the operation of the unit dangerous;
• The high temperature resistance of steel alloys and their thermal conductivity complicate the engine manufacturing process. Significant heat losses in the heat exchanger reduce the efficiency of the unit, and the use of specific materials makes the manufacture of the engine expensive;
• To adjust and switch the engine from mode to mode, special control devices must be used.

Usage

The Stirling engine has found its niche and is actively used where dimensions and omnivorousness are an important criterion:

• Stirling engine-generator.

A mechanism for converting heat into electrical energy. Often there are products used as portable tourist generators, installations for the use of solar energy.

• The engine is like a pump (electric).

The engine is used for installation in the circuit of heating systems, saving on electrical energy.

• The engine is like a pump (heater).

In countries with a warm climate, the engine is used as a space heater.

Stirling engine on a submarine:

• The engine is like a pump (cooler).

Almost all refrigerators in their design use heat pumps By installing a Stirling engine, resources are saved.

• The engine is like a pump that creates ultra-low heat levels.

The device is used as a refrigerator. To do this, the process is started in the opposite direction. The units liquefy gas, cool measuring elements in precise mechanisms.

• Underwater engine.

The submarines of Sweden and Japan work thanks to the engine.

Stirling engine as a solar installation:

• The engine is like a battery of energy.

Fuel in such units, salt melts, the engine is used as an energy source. In terms of energy reserves, the motor is ahead of chemical elements.

• solar engine.

Convert the sun's energy into electricity. The substance in this case is hydrogen or helium. The engine is placed in the focus of the maximum concentration of the energy of the sun, created using a parabolic antenna.

The reason for the construction of this unit was a stupid idea: "is it possible to build a steam engine without machines and tools, using only parts that can be bought in a store" and do everything yourself. The result is this design. The entire assembly and setup took less than an hour. Although the design and selection of parts took six months.

Most of the structure consists of plumbing fittings. At the end of the epic, the questions of the sellers of hardware and other stores: “can I help you” and “what are you for?” really pissed me off.

And so we collect the foundation. First, the main cross member. Tees, barrels, half inch corners are used here. I fixed all the elements with a sealant. This is to make it easier to connect and disconnect them by hand. But for finishing assembly it is better to use plumbing tape.

Then the longitudinal elements. A steam boiler, a spool, a steam cylinder and a flywheel will be attached to them. Here all the elements are also 1/2".

Then we make racks. In the photo, from left to right: the stand for the steam boiler, then the stand for the steam distribution mechanism, then the stand for the flywheel, and finally the holder for the steam cylinder. The flywheel holder is made from a 3/4" tee (outer thread). Bearings from a roller skate repair kit are ideal for it. The bearings are held in place by a compression nut. These nuts can be found separately or taken from a tee for multilayer pipes. right corner (not used in the design). A 3/4 "tee is also used as a holder for the steam cylinder, only the thread is all female. Adapters are used to fasten 3/4" to 1/2" elements.

We collect the boiler. A 1" pipe is used for the boiler. I found a second-hand one on the market. Looking ahead, I want to say that the boiler turned out to be small and does not produce enough steam. With such a boiler, the engine runs too sluggishly. But it works. The three parts on the right are: cap, adapter 1 "-1/2" and squeegee. The sling is inserted into the adapter and closed with a cap. Thus, the boiler becomes airtight.

So the boiler turned out initially.

But the sukhoparnik was not of sufficient height. Water entered the steam line. I had to put an additional 1/2" barrel through an adapter.

This is a burner. Four posts earlier was the material "Homemade oil lamp from pipes." Initially, the burner was conceived just like that. But there was no suitable fuel. Lamp oil and kerosene are heavily smoked. You need alcohol. So for now I just made a holder for dry fuel.

This is a very important detail. Steam distributor or spool. This thing directs steam into the working cylinder during the working stroke. When the piston moves back, the steam supply is cut off and discharge occurs. The spool is made from a crosspiece for metal-plastic pipes. One of the ends must be sealed with epoxy putty. With this end, it will be attached to the rack through an adapter.

And now the most important detail. It will depend on whether the engine will work or not. This is the working piston and spool valve. Here, an M4 hairpin is used (sold in furniture fittings departments, it is easier to find one long one and saw off the desired length), metal washers and felt washers. Felt washers are used to fasten glass and mirrors with other fittings.

Felt is not the best best material. It does not provide sufficient tightness, and the resistance to travel is significant. Subsequently, we managed to get rid of the felt. Not quite standard washers were ideal for this: M4x15 for the piston and M4x8 for the valve. These washers need to be as tightly as possible, through a plumbing tape, put on a hairpin and wrap 2-3 layers with the same tape from the top. Then carefully grind with water in the cylinder and spool. I did not take a photo of the upgraded piston. Too lazy to disassemble.

It's actually a cylinder. Made from a 1/2" keg, it is secured inside the 3/4" tee with two tie nuts. On one side, with maximum sealing, a fitting is tightly fastened.

Now flywheel. The flywheel is made from a dumbbell pancake. A stack of washers is inserted into the center hole, and a small cylinder from an inline skate repair kit is placed in the center of the washers. Everything is sealed. For the holder of the carrier, a hanger for furniture and paintings was ideal. Looks like a keyhole. Everything is assembled in the order shown in the photo. Screw and nut - M8.

We have two flywheels in our design. There must be a strong connection between them. This connection is provided by a coupling nut. All threaded connections are fixed with nail polish.

These two flywheels appear to be the same, however one will be connected to the piston and the other to the spool valve. Accordingly, the carrier, in the form of an M3 screw, is attached at different distances from the center. For the piston, the carrier is located further from the center, for the valve - closer to the center.

Now we make the valve and piston drive. The furniture connection plate was ideal for the valve.

For the piston, a window lock pad is used as a lever. Came like family. Eternal glory to the one who invented the metric system.

Assembled drives.

Everything is mounted on the engine. Threaded connections are fixed with varnish. This is the piston drive.

A Stirling engine is a kind of engine that starts to run on thermal energy. In this case, the source of energy is completely unimportant. The main thing is to make a difference temperature regime, in this case, such an engine will work. Now we will analyze how you can create a model of such a low-temperature engine from a can of Coca-Cola.

Materials and fixtures

Now we will analyze what we need to take to create an engine at home. What we need to take for stirling:

• Balloon.
• Three cans of cola.
• Special terminals, five pieces (for 5A).
• Nipples for fixing bicycle spokes (two things).
• Cotton wool.
• A piece of steel wire thirty cm long and 1 mm in cross section.
• A piece of large steel or copper wire with a diameter of 1.6 to 2 mm.
• Wooden pin with a diameter of twenty mm (length one cm).
• Bottle cap (plastic).
• Wiring (thirty cm).
• Special glue.
• Vulcanized rubber (about 2 centimeters).
• Fishing line (length thirty cm).
• Several weights for balancing (for example, nickel).
• CDs (three pieces).
• Special buttons.
• A tin can for creating a firebox.
• Heat resistant silicone and tin can for making water cooling.

Description of the creation process

Stage 1. Jars preparation.

First, you should take 2 cans and cut off the top of them. If the tops are cut off with scissors, the resulting notches will have to be ground off with a file.

Stage 2. Making the diaphragm.

As a diaphragm, you can take balloon, which should be reinforced with vulcanized rubber. The ball must be cut and pulled onto a jar. Then glue a piece of special rubber on the central part of the diaphragm. After the glue has hardened, in the center of the diaphragm we will punch a hole for installing the wire. The easiest way to do this is with a special button that can be left in the hole until assembly.

Stage 3. Cutting and creating holes in the lid.

Two holes of two mm must be made in the walls of the cover, they are necessary to install the pivot axis of the levers. Another hole must be made in the bottom of the lid, a wire will go through it, which will be connected to the displacer.

At the last stage, the lid must be cut off. This is done so that the displacer wire does not catch on the edges of the cover. For such work, you can take household scissors.

Stage 4. Drilling.

In the jar, you need to drill two holes for the bearings. In our case, this was done with a 3.5 mm drill.

Stage 5. Making a viewing window.

cut into the engine housing special window. Now it will be possible to observe how all the nodes of the device work.

Stage 6. Terminal modification.

It is necessary to take the terminals and remove the plastic insulation from them. Then we take a drill, and make through holes on the edges of the terminals. In total, three terminals need to be drilled. Leave two terminals undrilled.

Stage 7. Creating leverage.

As a material for the manufacture of levers, copper wire is taken, the diameter of which is only 1.88 mm. How exactly to bend the knitting needles, it is worth looking on the Internet. You can take steel wire, just with copper wire, it is more convenient to work.

Stage 8. Manufacturing of bearings.

To make the bearings, you will need two bicycle nipples. The hole diameter needs to be checked. The author drilled them through with a 2 mm drill.

Stage 9. Installation of levers and bearings.

Levers can be placed directly through the viewing window. One end of the wire should be long, the flywheel will lie on it. Bearings should sit firmly in the right places. If there is a backlash, they can be glued.

Stage 10. Making the displacer.

The displacer is made of steel wool for polishing. For the manufacture of the displacer, a steel wire is taken, a hook is created on it, and then a certain amount of cotton wool is wound around the wire. The displacer must be the same size so that it moves smoothly in the bank. The entire height of the displacer should not exceed five centimeters.

At the end on one side of the cotton it is necessary to make a spiral of wire so that it does not come out of the wool, and on the second side we make a loop from the wire. Then we will tie a fishing line to this loop, which will subsequently be attracted through the central part of the diaphragm. Vulcanized rubber should be in the middle of the container.

Step 11. Making the pressure tank

It is necessary to cut the bottom of the jar in a certain way so that about 2.5 cm remains from its base. The displacer together with the diaphragm must be moved to the reservoir. After that, this whole mechanism is transferred to the end of the can. The diaphragm needs to be tightened a little. so that it does not sag.

Then you need to take the terminal that was not drilled, and pass the fishing line through it. The knot must be glued so that it does not move. The wire must be lubricated with high quality oil and at the same time make sure that the displacer can easily stretch the line behind it.

Stage 12. Making push rods.

These special links connect the diaphragm and levers. This is made from a piece of copper wire fifteen cm long.

Stage 13. Creating and installing a flywheel

For the manufacture of the flywheel, we take three old CDs. Take as the center wooden rod. After installing the flywheel, bend the crankshaft rod, so the flywheel will no longer subside.

At the last stage, the entire mechanism is assembled completely.

The last step, creating a firebox

So we have reached the last step in the creation of the engine.

The Stirling engine, once famous, was forgotten for a long time due to the widespread use of another engine (internal combustion). But today we hear more and more about him. Maybe he has a chance to become more popular and find his place in the new modification in the modern world?

Story

The Stirling engine is a heat engine that was invented in the early nineteenth century. The author, as you know, was a certain Stirling named Robert, a priest from Scotland. The device is an external combustion engine, where the body moves in a closed container, constantly changing its temperature.

Due to the spread of another type of motor, it was almost forgotten. Nevertheless, thanks to its advantages, today the Stirling engine (many amateurs build it at home with their own hands) is back again.

The main difference from an internal combustion engine is that the heat energy comes from outside, and is not generated in the engine itself, as in an internal combustion engine.

Principle of operation

You can imagine a closed air volume enclosed in a housing having a membrane, that is, a piston. When the body is heated, the air expands and does work, thus arching the piston. Then cooling occurs, and it bends again. This is the cycle of the mechanism.

It is no wonder that many do-it-yourself thermoacoustic Stirling engines are made at home. The tools and materials for this require the very minimum that everyone has in their home. Consider two different ways how easy it is to create.

Work materials

To make a Stirling engine with your own hands, you will need the following materials:

• tin;
• steel spoke;
• brass tube;
• hacksaw;
• file;
• wooden stand;
• metal scissors;
• fastener details;
• soldering iron;
• soldering;
• solder;
• machine.

This is all. The rest is a matter of simple technique.

How to do

A firebox and two cylinders for the base are prepared from tin, of which the Stirling engine, made by hand, will consist. Dimensions are selected independently, taking into account the purposes for which this device is intended. Suppose the motor is being made for demonstration purposes. Then the sweep of the main cylinder will be from twenty to twenty-five centimeters, no more. The rest of the parts should fit in with it.

At the top of the cylinder for moving the piston, two protrusions and holes with a diameter of four to five millimeters are made. The elements will act as bearings for the location of the crank device.

Next, the working body of the motor is made (it will become ordinary water). Tin circles are soldered to the cylinder, which is rolled up into a pipe. Holes are made in them and brass tubes are inserted from twenty-five to thirty-five centimeters in length and with a diameter of four to five millimeters. At the end, they check how tight the chamber has become by filling it with water.

Next comes the turn of the displacer. For manufacturing, a blank is taken from wood. On the machine, they achieve that it takes the form of a regular cylinder. The displacer should be slightly smaller than the cylinder diameter. The optimal height is selected after the Stirling engine is made by hand. Therefore, at this stage, the length should assume some margin.

The spoke is turned into a cylinder rod. In the center of the wooden container, make a hole suitable for the stem, insert it. In the upper part of the rod, it is necessary to provide a place for the connecting rod device.

Then they take copper tubes four and a half centimeters long and two and a half centimeters in diameter. A circle of tin is soldered to the cylinder. On the sides on the walls, a hole is made to communicate the container with the cylinder.

The piston is also adjusted to lathe under the diameter of the large cylinder from the inside. At the top, the rod is connected in a hinged way.

The assembly is completed and the mechanism is adjusted. To do this, the piston is inserted into the cylinder bigger size and connect the latter to another smaller cylinder.

A crank mechanism is built on a large cylinder. Fix part of the engine with a soldering iron. The main parts are fixed on a wooden base.

The cylinder is filled with water and a candle is placed under the bottom. The Stirling engine, made by hand from start to finish, is checked for performance.

Second way: materials

The engine can be made in another way. For this you will need the following materials:

• tin;
• foam rubber;
• paperclips;
• disks;
• two bolts.

How to do

Foam rubber is very often used to make a simple, not powerful Stirling engine at home with your own hands. A displacer for the motor is prepared from it. Cut out the foam circle. The diameter should be slightly smaller than that of the tin can, and the height should be slightly more than half.

A hole is made in the center of the cover for the future connecting rod. To make it go smoothly, the paper clip is rolled into a spiral and soldered to the lid.

The foam circle in the middle is pierced with a thin wire with a screw and fixed on top with a washer. Then connect a piece of paper clip by soldering.

The displacer is pushed into the hole on the lid and the jar is connected to the lid by soldering to seal. A small loop is made on the paper clip, and another, larger hole is made in the lid.

The tin sheet is rolled into a cylinder and soldered, and then attached to the can so that there are no gaps at all.

The paper clip is turned into a crankshaft. The spacing should be exactly ninety degrees. The knee above the cylinder is made slightly larger than the other.

The remaining paper clips turn into racks for the shaft. The membrane is made as follows: the cylinder is wrapped in a polyethylene film, pressed through and fastened with a thread.

The connecting rod is made from a paper clip, which is inserted into a piece of rubber, and the finished part is attached to the membrane. The length of the connecting rod is made such that at the lower shaft point the membrane is drawn into the cylinder, and at the highest point it is extended. The second part of the connecting rod is made in the same way.

Then one is glued to the membrane, and the other to the displacer.

Can legs can also be made from paper clips and soldered. For the crank, a CD is used.

Here is the whole mechanism. It remains only to substitute and light a candle under it, and then give a push through the flywheel.

Conclusion

Such is the low-temperature Stirling engine (built with your own hands). Of course, on an industrial scale, such devices are manufactured in a completely different way. However, the principle remains the same: the air volume is heated and then cooled. And this is constantly repeated.

Finally, look at these drawings of the Stirling engine (you can do it yourself without any special skills). Maybe you are already on fire with the idea, and you want to do something similar?

Explanation of the operation of the Stirling engine.

We start by marking the flywheel.

Six holes failed. It turns out not beautiful. The holes are small and the body between them is thin.

For one, we sharpen counterweights for the crankshaft. The bearings are pressed in. Subsequently, the bearings are pressed out and a thread is cut into M3 in their place.

I milled but you can also file.

This is part of the rod. The rest is soldered by PSR.

Reamer work on the sealing washer.

Stirling bed drilling. The hole that connects the displacer with the working cylinder. Drill for 4.8 threaded on M6. Then it must be silenced.

Drilling the sleeve of the working cylinder, under the development.

Drilling for threading on M4.

How it was done.

The dimensions are given taking into account the reworked one. Two pairs of cylinder-piston were made, 10mm. and 15mm. Both were tested. If you put the cylinder on 15mm. then the piston stroke will be 11-12mm. and does not work. And here is 10mm. with 24mm travel. just right.

Dimensions of connecting rods. Brass wire Ф3mm is soldered to them.

Connecting rod mounting assembly. The bearing option did not work. When the connecting rod is tightened, the bearing deforms and creates additional friction. Instead of a bearing, I made Al. bushing with bolt.

Dimensions of some parts.

Some flywheel sizes.

Some dimensions are how to mount on the shaft and articulations.

Between the cooler and the flame chamber we put an asbestos gasket for 2-3mm. It is advisable to put paronite gaskets or something that conducts heat less under the bolts that tighten both parts.

The displacer is the heart of the stirling, it should be light and conduct little heat. The stock is taken from the same old hard drive. This is one of the linear motor guides. Very suitable, hardened, chrome plated. In order to cut the thread, I wrapped the middle with a soaked rag, and heated the ends to red.

Connecting rod with working cylinder. Overall length 108mm. Of these, 32mm is a piston with a diameter of 10mm. The piston should go into the cylinder easily, without noticeable scoring. To check, close it tightly with your finger from the bottom, and insert the piston from above, it should be very slowly released down.

I planned to do so but in the process I made changes. In order to find out the stroke of the working cylinder, move the displacer to refrigerator compartment, We extend the working cylinder by 25mm. We heat the flame chamber. Carefully put a ruler under the working connecting rod and remember the data. We sharply push the displacer, and how much the working cylinder will move is its stroke. This size plays a very important role.

View of the working cylinder. Connecting rod length 83mm. Stroke 24mm. The handwheel is attached to the shaft with an M4 screw. The photo shows his head. And in this way the counterweight of the displacer connecting rod is also attached.

View of the displacer connecting rod. Total length with displacer 214mm. Connecting rod length 75mm. Stroke 24mm. Pay attention to the U-shaped groove on the flywheel. It was made for power take-off. The idea was either a generator or a belt on the cooler fan. The upper part is milled on one side to a depth of 7mm and a length of 32mm. The center of the bearing from the bottom is 55mm. It is fastened from below with two bolts on M4. The distance between the centers of the pylons is 126mm.

View of the flame chamber and the cooler. The engine housing is pressed into the pylon. The dimensions of the pylon are 47x25x15, the recess for landing is 12mm. It is attached to the bottom of the board with two M4 bolts.

Lampada 40mm. in diameter height 35mm. Deepened into the shaft by 8mm. At the bottom, a M4 nut is soldered in the center and secured with a bolt from below.

Finished look. Base oak 300x150x15mm.

Nameplate.

I have been looking for a working circuit for a long time. I found it, but it was always connected with the fact that there were problems either with equipment or with materials. I decided to make it like a crossbow. After looking at many options and wondering what I have available and what I can do on my own equipment. Those dimensions that I figured out right away, with assembled apparatus I didn't like it. It turned out too wide. I had to shorten the cylinder bed. And put the flywheel on one bearing (on one pylon). The materials flywheel, connecting rods, counterweight, sealing washer, lamp and working cylinder are bronze. Pylons, working piston, cylinder bed, cooler and washer with a thread from the flame chamber aluminum. steel. Stainless steel flame chamber. Graphite displacer. And what happened I put on display, you be the judge.