Horizontal coke can engine question

Discussion on Stirling or "hot air" engines (all types)
Post Reply
commander
Posts: 2
Joined: Fri Feb 13, 2015 9:10 am
Location: England

Horizontal coke can engine question

Post by commander »

Hi to you all. I am a new member and intend to build a horizontal coke can engine as per the Jim Larsen video.
This will be my first stirling engine build ad I am sure I can do it, but one thing puzzles me. It concerns the
displacer piston. It seems to me that the displacer piston will sag on its bearing and drag on the bottom
of the cylinder causing friction in both cases. Can anyone explain how to get over this?

Chris.
Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Horizontal coke can engine question

Post by Ian S C »

Chris, You need a long well fitted glad for the displacer rod, and a rod that is rigid enough not to bend under the weight of the displacer, this is one advantage of the vertical engine.
My engines are machined on the lathe, and milling machine, I did build one tin can motor, but even that used parts that had been made for another engine.
Ian S C
commander
Posts: 2
Joined: Fri Feb 13, 2015 9:10 am
Location: England

Re: Horizontal coke can engine question

Post by commander »

Thanks Ian. That makes perfect sense. I have seen one design that has the rod going right through the displacer piston
and out at the far end of the cylinder through another gland, thus holding the piston in place horizontally. I did not want
to do this as it creates another possible source of an air leak, and also the rod and consequently the piston would get
hot from the heat source. I shall not be starting for a few weeks as I have a model ship to finish first. I will let you, and all,
know how it goes.

Chris.
Ian S C
Posts: 2218
Joined: Thu Dec 02, 2010 5:15 am
Location: New Zealand

Re: Horizontal coke can engine question

Post by Ian S C »

Chris, now you will have to build an engine for the ship, I'v got a tin hull with a GAMMA version of Koichi Hirata's ALPA motor that he designed for a boat (look him up in Google).
My current build, a rhombic drive GAMMA has a very long gland as it is forked at the end to take the two con rods, and they must clear the cylinder, so about 1 7/8" long, this engine will be horizontal, although most of my designs are vertical in an attempt to reduce friction.
Ian S C
Post Reply