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. Let's look at 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.
It's 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 into 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 on a lathe to 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 a larger cylinder and the latter is connected 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?
The well-known Stirling engine can be created independently from improvised materials. Any heat source in this design is able to give you energy at the exit of the device.
materials
To make a Stirling engine with your own hands you will need:
- CD - disk;
- plastic holder from under CDs;
- aluminum sheet measuring 25 x 13 cm;
- epoxy resin;
- wire;
- 7" PVC pipe;
- Styrofoam;
- copper pipe ¾ inch;
- adhesive tape;
- thermal gun and hot glue;
- hacksaw for metal;
- drill;
- wire cutters;
- jigsaw;
- compass.
Step 1. It is necessary to cut off part of the structure from the CD holder. The result should be a circle without a bottom and top with smooth edges. Height - about 4 cm.
Step 2. Use a compass to measure the diameter of the resulting circle. Transfer it to the foam. Make two circles. Be sure to mark the center. Sand the circles with a jigsaw. Glue them. For a clear fit in the circle, glue the outer edge with duct tape.
Step 3. Cut out circles with a diameter of the circumference of a CD holder from aluminum sheets. There should be two.
Step 4. Exactly in the middle of the top aluminum sheet, drill a hole into which the wire will enter. To make the wire move straight, as we need it, weld a piece of an angled pipe, as shown in the photo. In his top hat, make another hole for the wire. Take the wire itself that will hold the piston, check that it can move through these holes, but at the same time there is also a tightness.
Closer to the edge of the top cover, drill another hole with a diameter equal to a piece of the existing metal pipe.
Step 5. Now you need to make a piston. To do this, take a piece of metal pipe, which will then go into this design. Rinse it and place it on a lid lined with a piece of plastic bag. Lubricate the inside of the tube and the bag itself with oil. After that, pour into the resulting mold, heated epoxy. It should be warm, not hot. As it solidifies with force, you will have to push out the learned piston. Form a hook from the wire. Drill a hole in a piece of epoxy and insert this wire into it. The piston is ready.
Step 6. Part of the structure needs to be assembled. Glue the bottom of the structure with hot glue. Also make a few more wire hooks. Cut the hook, which will be located in the middle of the whole structure. Seal the ends of the hooks with epoxy.
Step 7. Fasten the pipe to the aluminum top sheet. Lubricate it, insert the piston. Make a layout of the moving part of the structure. To do this, simply attach paper and make basic markings. Bend the wire according to the drawn layout.
Step 8. Drill a hole in the hooks, slightly larger than the main wire.
Step 9. Cut the PVC pipe in half and attach it to the aluminum base with hot glue. Make holes in the pipe into which you put the wire crankshaft. Attach a plastic jar lid or CD to the other end of the shaft. They must rotate.
Hello! Today I want to bring to your attention a homemade engine that converts any temperature difference into mechanical work:
Stirling's engine- a heat engine in which a liquid or gaseous working fluid moves in a closed volume, a kind of external combustion engine. It is based on periodic heating and cooling of the working fluid with the extraction of energy from the resulting change in the volume of the working fluid. It can work not only from fuel combustion, but also from any heat source.
I present to your attention my engine, made from pictures from the Internet:
Seeing this miracle, I had a desire to make it)) Moreover, there were many drawings and engine designs on the Internet. I will say right away: it is not difficult to do, but it is a bit problematic to adjust and achieve normal operation. It worked fine for me only the third time (I hope you won’t suffer like that)))).
Stirling engine working principle:
Everything is made from materials available to every brain:
Well, how about without sizes)))
The frame of the engine is made of wire from paper clips. All fixed wire connections are soldered()
The displacer (the disk that moves the air inside the engine) is made of drawing paper and glued with superglue (it is hollow inside):
The smaller the gap between the covers and the displacer in the upper and lower positions, the greater the efficiency of the engine.
The displacer rod is made from a blind rivet (manufacturing: carefully pull out the inner part and, if necessary, clean it with zero sandpaper; glue the outer part to the upper “cold” cover with the cap inward). But this option has a drawback - there is no complete tightness and there is little friction, although a drop of engine oil will help get rid of it.
Piston cylinder - neck from an ordinary plastic bottle:
The piston casing is made of a medical glove and secured with a thread, which, after winding, must be impregnated with superglue for reliability. A disk made of several layers of cardboard is glued in the center of the casing, on which the connecting rod is fixed.
The crankshaft is made from the same paper clips as the entire engine frame. the angle between the knees of the piston and the displacer is 90 degrees. The working stroke of the displacer is 5 mm; piston - 8mm.
Flywheel - consists of two CD discs that are glued to a cardboard cylinder and planted on the crankshaft axis.
So, stop talking nonsense, I present to you engine running video:
The difficulties I had were mainly due to excessive friction and the lack of accurate dimensions of the structure. in the first case, a drop of engine oil and crankshaft alignment corrected the situation, then in the second, you had to rely on intuition))) But as you can see, everything turned out (though I completely redid the engine 3 times))))
If you have any questions - write in the comments, we'll figure it out)))
Thank you for your attention)))
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Explanation of the operation of the Stirling engine.
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We start by marking the flywheel.
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Six holes failed. It turns out not beautiful. The holes are small and the body between them is thin.
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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.
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I milled but you can also file.
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This is part of the rod. The rest is soldered by PSR.
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Reamer work on the sealing washer.
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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.
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Drilling the sleeve of the working cylinder, under the development.
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Drilling for threading on M4.
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How it was done.
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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.
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Dimensions of connecting rods. Brass wire Ф3mm is soldered to them.
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Connecting rod mounting assembly. Bearing option failed. When the connecting rod is tightened, the bearing deforms and creates additional friction. Instead of a bearing, I made Al. bushing with bolt.
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Dimensions of some parts.
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Some flywheel sizes.
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Some dimensions are how to mount on the shaft and articulations.
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Between the cooler and the flame chamber we put an asbestos gasket for 2-3 mm. It is advisable to put paronite gaskets or something that conducts heat less under the bolts that tighten both parts.
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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.
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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 tangible scuffing. To check, close it tightly with your finger from the bottom, and insert the piston from above, it should be very slowly released down.
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I planned to do so but in the process I made changes. In order to find out the stroke of the working cylinder, we move the displacer into the refrigerating chamber, and pull the working cylinder 25 mm. We sharply push the displacer, and how much the working cylinder will move is its stroke. This size plays a very important role.
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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.
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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.
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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.
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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.
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Finished look. Base oak 300x150x15mm.
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Nameplate.
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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 myself on my own equipment. I didn’t like the dimensions that I figured out right away when the device was assembled. It turned out to be 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.
A Stirling engine is an engine that can run on thermal energy. In this case, the source of heat is absolutely not important. The main thing is that there is a temperature difference, in which case this engine will work. The author figured out how to make a model of such an engine from a can of Coca-Cola.
Materials and tools
- one balloon;
- 3 cans of cola;
- electrical terminals, five pieces (for 5A);
- nipples for attaching bicycle spokes (2 pieces);
- metal wool;
- a piece of steel wire 30 cm long and 1 mm in cross section;
- a piece of thick wire made of steel or copper with a diameter of 1.6 to 2 mm;
- a pin made of wood with a diameter of 20 mm (length 1 cm);
- bottle cap (plastic);
- electrical wiring (30 cm);
- Super glue;
- vulcanized rubber (about 2 square centimeters);
- fishing line (length about 30 cm);
- a pair of weights for balancing (for example, nickel);
- CDs (3 pieces);
- pushpins;
- another tin can for making a firebox;
- heat-resistant silicone and a tin can to create water cooling.
Step one. Jars preparation
First of all, you need to take two jars and cut off their tops. If the tops are cut with scissors, the resulting notches will need to be ground off with a file.
Next, you need to cut the bottom of the jar. This can be done with a knife.
Step two. Creating an Aperture
As a diaphragm, the author used a balloon, which was reinforced with vulcanized rubber. The ball must be cut and pulled over the jar, as indicated in the picture. Then a piece of vulcanized rubber is glued to the center of the diaphragm. After the glue hardens, a hole is punched in the center of the diaphragm for installing the wire. The easiest way to do this is with a pushpin, which can be left in the hole until assembly.
Step three. Cutting and creating holes in the lid
In the walls of the cover, you need to drill two holes of 2 mm each, they are needed to install the pivot axis of the levers. Another hole must be drilled in the bottom of the lid, a wire will pass through it, which will be connected to the displacer.
At the final stage, the cover must be cut as shown in the picture. This is done so that the displacer wire does not cling to the edges of the cover. For such work, utility scissors are suitable.
Step four. Drilling
In the jar, you need to drill two holes for the bearings. In this case, this was done with a 3.5 mm drill.
Step five. Creating a viewing window
A viewing window must be cut into the engine housing. Now it will be possible to observe how all the nodes of the device function.
Step six. Terminal modification
You need to take the terminals and remove the plastic insulation from them. Then a drill is taken, and through holes are made at the edges of the terminals. In total, you need to drill 3 terminals, while two should remain undrilled.
Step seven. Creating leverage
As a material for creating levers, copper wire is used, the diameter of which is 1.88 mm. How exactly to bend the knitting needles is shown in the pictures. You can also use steel wire, it's just more pleasant to work with copper wire.
Step eight. Creation of bearings
To make bearings, you will need two bicycle nipples. The hole diameter needs to be checked. The author drilled them through with a 2 mm drill.
Step nine. Installation of levers and bearings
The levers can be installed directly through the viewing window. One end of the wire should be long, it will have a flywheel. The bearings must be firmly in place. If there is a backlash, they can be glued.
Step ten. Creating a Displacer
The displacer is made of steel wool for polishing. To create a displacer, a steel wire is taken, a hook is made on it, and then the required amount of cotton wool is wound on the wire. The displacer must be large enough to move freely in the can. The total height of the displacer should not exceed 5 cm.
As a result, on one side of the cotton wool, it is necessary to form a spiral of wire so that it does not come out of the cotton wool, and on the other side a loop is made of the wire. Next, a fishing line is tied to this loop, which is subsequently pulled through the center of the diaphragm. The vulcanized rubber should be in the middle of the container.
Step 11 Create a Pressure Tank
It is necessary to cut the bottom of the jar so that about 2.5 cm remains from its base. The displacer together with the diaphragm must be placed in the tank. After that, this whole mechanism is installed at 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 stretch the fishing line through it. The knot must be glued so that it does not move. The wire must be well lubricated with oil and at the same time make sure that the displacer easily pulls the line along.
Step 12 Create Push Rods
Push rods connect the diaphragm and levers. This is done with a piece of copper wire 15 cm long.
