This is the first Stirling engine I've built in 28 years, far too long to wait! It's not exactly a very low temp difference engine since it requires at least hot water to run well, but it will run between 30 and 500 rpm. It incorporates some novel design innovations: 1) a thin layer of steel wool spot glued to the aluminum heater and cooler plates to facilitate heat transfer. The layer is pretty much flattened out when the displacer hits it. 2) the displacer is made of blue foam insulation but has two pieces of aluminum foil glued to it, one on each top and bottom half, again to facilitate heat transfer and regeneration. 3) the displacer is driven by a side shaft that protrudes halfway into the displacer and is attached to a small pivot rod at the center line. This eliminates the usual problem of sliding shaft air leakage since it's completely sealed. The bushing through the cylinder is a soft rubber grommet from an old CD drive. The power piston is graphite in a pyrex glass tube. The bearings and magnet counterweight are courtesy of some old hard drives. The flywheel is the bottom of a coffee can. The cylinder is clear plastic from a dust collector accessory. The aluminum plates are sealed with red RTV silicone. The phase angle is adustable, as is the power piston stroke. This has been a fun project and I'm looking forward to trying out some other ideas on bigger engines. I'll be posting a video of this engine running on ice at 30 rpm, just barely turning over. Thanks!
Wednesday, July 18, 2012
Novel model Stirling engine, 68 min. on one cup of hot water
Novel model Stirling engine, 68 min. on one cup of hot water Video Clips. Duration : 1.75 Mins.
This is the first Stirling engine I've built in 28 years, far too long to wait! It's not exactly a very low temp difference engine since it requires at least hot water to run well, but it will run between 30 and 500 rpm. It incorporates some novel design innovations: 1) a thin layer of steel wool spot glued to the aluminum heater and cooler plates to facilitate heat transfer. The layer is pretty much flattened out when the displacer hits it. 2) the displacer is made of blue foam insulation but has two pieces of aluminum foil glued to it, one on each top and bottom half, again to facilitate heat transfer and regeneration. 3) the displacer is driven by a side shaft that protrudes halfway into the displacer and is attached to a small pivot rod at the center line. This eliminates the usual problem of sliding shaft air leakage since it's completely sealed. The bushing through the cylinder is a soft rubber grommet from an old CD drive. The power piston is graphite in a pyrex glass tube. The bearings and magnet counterweight are courtesy of some old hard drives. The flywheel is the bottom of a coffee can. The cylinder is clear plastic from a dust collector accessory. The aluminum plates are sealed with red RTV silicone. The phase angle is adustable, as is the power piston stroke. This has been a fun project and I'm looking forward to trying out some other ideas on bigger engines. I'll be posting a video of this engine running on ice at 30 rpm, just barely turning over. Thanks!
This is the first Stirling engine I've built in 28 years, far too long to wait! It's not exactly a very low temp difference engine since it requires at least hot water to run well, but it will run between 30 and 500 rpm. It incorporates some novel design innovations: 1) a thin layer of steel wool spot glued to the aluminum heater and cooler plates to facilitate heat transfer. The layer is pretty much flattened out when the displacer hits it. 2) the displacer is made of blue foam insulation but has two pieces of aluminum foil glued to it, one on each top and bottom half, again to facilitate heat transfer and regeneration. 3) the displacer is driven by a side shaft that protrudes halfway into the displacer and is attached to a small pivot rod at the center line. This eliminates the usual problem of sliding shaft air leakage since it's completely sealed. The bushing through the cylinder is a soft rubber grommet from an old CD drive. The power piston is graphite in a pyrex glass tube. The bearings and magnet counterweight are courtesy of some old hard drives. The flywheel is the bottom of a coffee can. The cylinder is clear plastic from a dust collector accessory. The aluminum plates are sealed with red RTV silicone. The phase angle is adustable, as is the power piston stroke. This has been a fun project and I'm looking forward to trying out some other ideas on bigger engines. I'll be posting a video of this engine running on ice at 30 rpm, just barely turning over. Thanks!
