Двигун стірлінга

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор

31.07.2015

ДВИГУН СТІРЛІНГА

Двигун Стірлінга являє собою тепловий двигун винайдений Робертом Стирлингом в 1816 році. Він відрізняється від двигуна внутрішнього згоряння, тому що паливо згорає поза двигуна, що робить його набагато простіше у виготовленні. Є двигуни Стірлінга, які працюють від тепла ваших рук, хоча їх небагато складніше побудувати. Двигун Стірлінга буде непоганим доповненням до будь-якої колекції любителів робити речі своїми руками.

Основний принцип роботи двигуна Стірлінга полягає в постійно чередуемых нагріванні й охолодженні робочого тіла в закритому циліндрі. Зазвичай в ролі робочого тіла виступає повітря, але також використовуються водень і гелій. У ряді експериментальних зразків випробовувалися фреони, двоокис азоту, скраплений пропан-бутан і вода. В останньому випадку вода залишається в рідкому стані на всіх ділянках термодинамічного циклу. Особливістю стірлінга з рідким робочим тілом є малі розміри, висока питома потужність і великі робочі тиску. Існує також стірлінг з двофазним робочим тілом. Він теж характеризується високою питомою потужністю, високим робочим тиском.

Збірка двигуна Стірлінга своїми руками(мовою оригіналу)

Drawing pin

Super Glue

Red temperature resistant silicone

Tuna can for a water Jacket

Text instructions below.

Step 1: Prepare two coke cans

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
since I have bought a shiny new can opener which opens cans perfectly, ignore this nonsense about tin snips and sanding wheels.

Firstly you need two coke cans with their inside of their tops cut off. Use the tin snips to cut them, this will leave a lethal jagged edge which you must clean up either using a metal file or a small flap sander (could also use a Dremel)

Then cut the bottom off the cans using a Stanley knife. Try not to crease the metal as this will reduce the chances of it being airtight. Some people say that you can use a can opener to remove the tops of the cans however I found that it destroys the sides of the can, you might have more luck!

Step 2: Make the diaphragm

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
The diaphragm of this engine is made from a balloon (just an ordinary one, nothing special!). It’s reinforced with a piece of inner tube in the centre First of all cut the neck off a balloon and the stretch balloon end over the top of a can. Then cut a piece of inner-tube rubber about 1cm square glue and it in the centre of the balloon.

Once the glue is dry, you can use a drawing pin to pierce a hole in the centre of the diaphragm for the displacer wire. Leave the pin in the hole until your ready to fit the displacer later.

Step 3: Cut and drill the bottle cap

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Drill a 2mm hole in either side of the bottle cap for the crank pivot, and a hole in the centre for the displacer wire.

Then cut either side of the bottle cap into a curved shape, this is because sometimes the displacer wire holder flicks to the side a little and it may hit the cap — This is more of an annoyance than a real problem, but you might as well prevent it if you can! Plus I think it looks better with the curves. I used tin snips here — they work well for cutting this thick plastic.

Now remove the diaphragm from the coke can flip and it over so that the inner-tube is on the inside of the can. Glue the bottle cap to the side of the diaphragm that does not have the inner-tube reinforcement. I sanded the bottle cap a little as I found that the glue doesn’t like to stick to this plastic.

The pin is left in place to line up the holes for the wire.

Step 4: the Drill bearing holes

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
I used a long 3.5 mm drill bit to the drill bearing holes. I just drilled them by eye, no need to measure anything. They should be near the top of the where can it bevels in. Make sure that they’re roughly level.

Step 5: Cut the viewing hole

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Next, mark a circle roughly in the centre of the can, so that you can see the cranks/displacer wire etc. It doesn’t have to be a circle, but that makes fitting the trim easier.

Step 6: Separate some electrical connectors and drill them

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Now you need to get some electrical terminal blocks and remove the plastic protection. The best way to get them out of their plastic blocks is to unscrew the screws as much as you can, then twist off the plastic around the screw thread with pliers.

Now drill a 2mm hole straight through the end of each one, as shown. You need three of these drilled. To drill them I held them with pliers.

You also need two of these not drilled in any way.

Step 7: Make the cranks

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
For the cranks I used some 1.8 mm (approx — I don’t know the exact size) copper wire — you can use old spokes, or steel wire, if you don’t have copper. I used copper because it’s easier to bend and I like copper. If you need to straighten the copper wire you can clamp it in a drill and hold the other end with some pliers — spinning the drill should straighten the wire. Make sure you wear some decent safety gear though, in case the wire slips!

I’ve included photo’s of every step of bending the cranks below. The displacer piece should protrude about 20mm and the other parts protrude about 5mm, no need to be exact though. The displacer part is at 90 degrees to the push rods — this is the best angle for this engine.

The electrical blocks are fitted as you bend the cranks, be careful to make sure that they all point the same way, as you won’t be able to access the screws from the viewing window.

Step 8: the Drill bearings

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
I used two spoke nipples for the bearings. You can get at these bike shops or scavenge them from old buckled/broken wheels.

Check your cranks before you drill them, they might fit without being drilled.

Like the terminal blocks, I drilled them out with a 2mm drill bit to remove the thread.

Step 9: Fit the cranks bearings and

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Now you can the thread cranks though. You can thread them through the viewing window at an angle. If you can’t fit them through you can cut one end down a little until they do. You need to leave one end of the cranks long for the flywheel attachment though. The bearings should be a tight fit in the holes but if they are loose you can glue them in place.

Make sure that the screws point towards the viewing window so that you can tighten them.

Step 10: Make the displacer

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
The displacer is made from steel wire wool wrapped around around a piece of steel wire. Bend a small hook in the end of the wire and begin rolling steel wool around this. Once you get near the size of a coke can, cut the wool. Pull out the wire most of the way and cut the wool so that the displacer is around 2 inches high. On the other end of the wire (not the hook end — bend a spiral, this is just to give the wire more surface area so it can’t be pulled out. Finally trim a slight bevel around the top to match the bevel on the coke can.

You can test the displacer in a coke can now — it needs to fall freely under it’s own weight. You can spin the displacer inside of the can to smooth it out. Try and make the spiral roughly into the shape of a coke can dome. Once your happy with the displacer movement you can tie about a foot of fishing wire onto the hook end of the displacer. Apply some super glue to the knot so that it can’t wriggle loose when the engine is running.

Now you can remove the pin from the diaphragm, so you can thread the loose end of the fishing wire through the diaphragm so that the inner-tube rubber will be on the inside of the pressure vessel.

Step 11: Make the pressure vessel.

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Cut the bottom off a coke can leaving about an inch from the base. Put the displacer and balloon into the pressure vessel, then push this base into the end of the can. Check that the displacer still moves freely.

Now fit the balloon over the top it should not be tight or loose — just tight not enough to sag.

Take an electrical connector that is not drilled tie and the fishing line through the screw hole about an inch above the bottom of the bottle cap — make sure that the displacer is at the bottom of the pressure vessel by tapping it on the table. Glue the knot so that it can’t come lose. Apply a drop of oil to the wire and check that the displacer can be pulled easily and that it falls easily pulling the wire with it.

Step 12: Make the push rods

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
Now you can make the push rods that connect the diaphragm to the cranks. Begin by taking a piece of copper wire (about 15cm long), threading it through the two holes in the side of the bottle cap. Then the push rods are bent inwards to match the distance of the cranks. You will need to cut the rods to length, they should just fit into the terminal blocks when their respective crank arms are pointing downward. Make sure that the rods can pivot freely in the bottle cap.

Step 13: Making the flywheel

ДВИГУН СТІРЛІНГА . Моделіст-Конструктор
To make the flywheel, I used a 1cm piece of 20mm wooden dowel as a centre for some old CD’s. The dowel was about 0.5 mm to big for the CD centres, so I had to sand it down a bit. Drill a 2mm hole all the way through the centre of the dowel and another around 3mm from the outside, about 5mm deep. This is so the crank shaft can be bent back on itself, to grip the flywheel. The CD’s are just glued to this

Короткий опис статті: двигун стірлінга

Джерело: ДВИГУН СТІРЛІНГА | Моделіст-Конструктор

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