recoiling displacer

[fullofhotair]

The head and foot of the displacer would have springs embedded .As the displacer reaches the cold end the springs would contact the top of the cylinder and compress into the displacer. Taking the shock out of the stroke and then recoiling. The same for the hot end.

[Ian S C]

fullofhotair, that just about explains the free piston engine I'm working on at the moment, it's working ok, just having a little (I hope) problem with the cooling system, but I can run a transistor radio of the linear alternator. The displacer has two springs on the rod, one inside at the bottom (the rod sticks out the bottom end), and one at the outside that stops the displacer hitting the top (hot end). This is a rebuild of a motor I built about 10yrs ago, and so far is working much better than the original, even though it's using the same displacer, and power piston. At the moment the hot cap is mild steel as the old one was, I must find a bit of stainless exhaust pipe with a 38 mm bore. Ian S C

[fullofhotair]

Ian SC
That's great. You even have the original design to compare it to. Does this engine have a regenerator?

[Ian S C]

The only regeneration is on the displacer piston it's self, it's 35 mm dia X 120 mm long, in a 38 mm cylinder, and at maximum stroke it's got quite a bit of dead space at the ends. I made the transfer port between the cylinders about 4 times the size of the original motor, Just got to hope I'v fixed the leak in the cooling system, the water was getting in the bottom of the displacer cylinder, from there to the power cylinder, water injection is not a benefit. Ian S C