First Beta Type Stirling Engine

[Piteco]

Hello everybody!

I've read the last month a lot of things about the stirling engine, specifically the beta type. So, now i want to do my own project and need some help guys. I read a lot of topics here in this forum and found out a lot of good information, so i decided to start the design of my project.
The main dimensions are :
Cylinder ID : 23.4mm (it is a tube of 1" with 1mm wall thickness)
Hot cylinder Lenght : 86mm
Cold cylinder lenght : 70mm
Displacer diameter : 21,4mm
Displacer lenght : 62,2mm
Displacer stroke : 40mm (for exact ratio of 1:1,5 it should be 41,97mm)
Power piston diameter : 23,4mm
Power piston lenght : 23mm
Power piston stroke : 23,4mm

But I have some doubts about it. Are these dimensions mutually compatible? If it's correct, how can I predict the performance of this engine? RPM? Torque? etc. I'm thinking of using a heat source of 750°C with a torch.
Below there's some images of it. On the images is missing the support of the engine, i have not done it yet in CAD model.
Thanks for any help you can give.

[Piteco]

I'm trying to figure out the dimensions of the flywheels. I'm thinking on use 2 flywheels made of Steel with 3" diameter and 3/8" thickness. How can I calculate if the inertia of the discs is enough comparing to the pistons inertia?
Some information i forgot to give you : The cylinder will be made by SS, the heat exchanger of aluminium, the power piston of brass.
I've made some changes in the crankshaft, later i'll upload the 3D model of it.

Thanks for any help you can give.

[Piteco]

New pics after the changes I've made.
See what you think about it.
Thanks.

[Ian S C]

I'd go to making the flywheels a bit heavier, if all you have is 3/8" steel, I'd make each of them from two bit bolted together, three cap screws around the rim is enough to hold it together.
Ian S C

[Piteco]

Thanks Ian S C! I've not machined it yet, so I can change to make it a lit bit heavier. The other parts do you think it is right?
I'm a little bit concerned if it will work, because a friend of mine did a project of a stirling beta type and it didn't work.
Thanks!

[Ian S C]

Piteco, it looks OK to me, as long as the piston is a good fit, it should just slide down the cylinder under it's own weight. Then if you block the hole for the displacer rod, put the piston in the cylinder, and block the end, the piston should slide very slowly, or even stop. There should be minimal air leakage at the gland through the piston. All the bearings must be free running.
If the motor is any good, I think you will find that it will actually run without a flywheel, it wont have any power, but it will run quite fast. It's sometimes difficult to turn the motor over without the FW.
Tell your friend to keep trying, on my first motors I ended up with a sore wrist from trying to start them, they sometimes take a bit of work to get them running, but if you get the friction to a minimum it should go.
Ian S C

[Piteco]

Thanks! I'm buying the material next week, and I will start the machining on april 11th.
As I finish the parts I'll post here the results and the first trials.
Thanks for all the tips!!!

[Piteco]

Hello,

This week i've looked the tube for the cylinder and the tube I used in design is not that easy to find, so I've changed the tube for OD=1" ID=23mm its wall thickness is 1.2mm. The new piston diameter is 23mm for the power piston and 21mm for the displacer. Beyond that, I've changed the stroke of the pistons to 20mm (power piston - it was 23,4mm) and 36mm (displacer - now I get exactly 1:1,5 ratio). The clearance between pistons is 1,5mm and the clearance between the displacer and the bottom of the cylinder is 1,5mm too.o you think this changes could be a problem? (I've changed the lenght of displacer and cylinder as well)
Thanks!

[dannipaff]

It is pollution free engine and use of any type of fuel characteristics and it ... The engine, then called the economizer, was first developed and patented by Rev. ... is a special-purpose piston, used in Beta and Gamma type Stirling engines, ...

[Piteco]

Hi everyone!

I've been working a lot last weeks, machining the parts of the engine. This weekend I'll start to build the crankshaft, which will take me some time.
The heat exchanger is almost done. I hope to post here the pics of all components and the engine assembled on sunday.

Cheers!

[Ian S C]

By heat exchanger(I see you mention aluminium) I presume this is at the cold end, for cooling.
Ian S C

[Piteco]

Yes, it is. For the cold chamber.

[Ian S C]

That's ok, it's just that aluminium doesn't like heat, well not too much.
Ian S C

[Piteco]

Guys,

Today I assembled the engine and it worked!!! It was awesome!!!! I'm very happy and proud! Thanks to everyone who helped !!!
Below the link to the video:

https://youtu.be/7GYh--ukyug

I tried with a can filled with kerosene, but the flame wasn't focused on the engine, so i used the torch.

I made another reciepient to put the kerosene, but I haven't tested yet.

The first picture is the "can" I used. lol....
The second and third the "new can" to put Kerosene.
The 4th and 5th pictures the final assembly.

[burnit0017]

Congratulations, thanks for posting the video.