MM-5 leak, displacer/power piston contact
Posted: Sun Mar 02, 2008 7:00 am
Hello,
Yesterday I finished assembling my first Stirling engine; the MM-5.
Great experience and it runs very well even though it has a leak that
caused the Air Leak test to fail repeatedly. After much trouble
shooting, I found the leak source to be at the displacer rod tube.
The engine seems to run fine (ran for 35 min. yesterday on a cup of
boiling water), but I think it would run better if this leak was
eliminated.
Also the displacer on it's uppermost travel makes contact with the
power piston at it's lowermost travel. I can see the contact cause
the foam displacer to bend, and I see this makes the displacer rod
shift, pressing it against the displacer tube. This surely causes a
reduction in engine performance.
I'm sure that others have experienced the same situations with their
MM-5's. Does anyone have suggestions on how to minimize the leak and
prevent the displacer/power piston contact?
Also, if anyone has an MM-1 (pre-assembled engine), does it have the
displacer/power piston contact problem?
Thanks in advance for your help,
Bud Wood
Yesterday I finished assembling my first Stirling engine; the MM-5.
Great experience and it runs very well even though it has a leak that
caused the Air Leak test to fail repeatedly. After much trouble
shooting, I found the leak source to be at the displacer rod tube.
The engine seems to run fine (ran for 35 min. yesterday on a cup of
boiling water), but I think it would run better if this leak was
eliminated.
Also the displacer on it's uppermost travel makes contact with the
power piston at it's lowermost travel. I can see the contact cause
the foam displacer to bend, and I see this makes the displacer rod
shift, pressing it against the displacer tube. This surely causes a
reduction in engine performance.
I'm sure that others have experienced the same situations with their
MM-5's. Does anyone have suggestions on how to minimize the leak and
prevent the displacer/power piston contact?
Also, if anyone has an MM-1 (pre-assembled engine), does it have the
displacer/power piston contact problem?
Thanks in advance for your help,
Bud Wood