@dmanofdland That is correct with the exception of my last Ringbom where the tube was already coming from the top like in this one. The old tube was only 3 mm inner diameter which was too narrow a passage for the air and air viscosity reduced the engine power a lot. This last tube is 5 mm and that made the engine a lot more powerful. Ideally the passage between the two cylinders should be as wide and as short as possible.
@dmanofdland The cylinder at the bottom is connected to the glass cylinder on top. But it is not the displacer. The displacer is a piston that is attached to the end of the brass rod. It moves inside the metal cylinder. It is not tight, it has clearance of about 2 mm from the walls of the cylinder, its job is not to provide compression, but to move air inside the metal cylinder from hot to cool end and back (hence name "displacer").
@blg53 The force that moves the displacer is created by the air pressure exerted by the moving (heavy) glass power piston to the relatively large (8 mm) diameter of the displace's push rod. And yes it still moves it despite imperfect seal between the rod and its bearing. Because the displacer and its rod are made to be very light and the presence of the repelling magnets counteracts whatever weight id does have making it gravity-neutral. When not in motion the displacer rod sits (levitates)
@dmanofdland No, no cyringe there. The displacer rod is a thin-walled brass tube with 8 mm outer diameter. The sleeve (bearing ) it slides through is a relatively thick-walled aluminim tube with 8 mm internal diameter. The choice of meterials is not perfect, both are too soft and as a result don't keep the polish well. But it was all I had. The seal is far from perfect, but I figured it was better to keep is slightly loose than too tight. I used graphite powder as a lubricant .
@dmanofdland Did not have to. The power piston and the cylinder are the two parts of a 20 cc glass cyringe, they are made to have a tight and accurate seal. All I had to do is to put a bit of weight on top of the pistin to give it inertia that acts the same way a flywheel does.
Have you seen the new diode flash lights that ar charged by movment of a magnet thru a tube just as what you have here, but with an inductive coil wound about the sleave in wich the magnetic piston moves.
Thanks for kind words, I was pretty thrilled when it started chugging along. The displacer weight could be an issue if the displacer push rod diameter is too small, mine is 8 mm which seems enough for the levitating (gravity-neutral) displacer. I will experiment with the weight of the power piston though, because it's functional purpose is to provide the overdrive push for the displacer, what the flywheel normally does, so it should be reasonabley weighty.
I am afraid I do not have the same feeling! the power piston can be efficcient without to much weight the "spring gas" will play the role of the flywheel but displacer and piston mass should be balanced... check my videos (without displacer!!!).
Checked your videos. If I understand you correctly your pet Stirling system is laminal flow or thermodynamic ones which works on the resonant standing wave along the regenerator stack with temperature gradient. This is I guess what you call "spring gas".There the power piston has to be very light. Mine are more conventional Stirling engines, there are no "spring" in the gas there, ie no acoustic resonance.
The pressure to move the displacer rod and the displacer with it is provided by inertial overdrive of either flywheel (Ringbom) or a heavy (inertial) power piston (Free Piston system). The displacer push rod has to be of reasonably large diameter so that it provides sufficient application area for this pressure to exert enough force to move it (and the displacer with it). Al least this is my understanding of how it works.
Oh, and in this system the displacer should be as light as possible as the enegy to move it is subtracted from the output. The heavier the displace is, the less efficient the engine is, the less power output.
My guess is that you can probably fit two O-rings both side of the light displacer to store energy at each dead point and then increase the length of your cylinder to reach a 2.5 inch displacement of the piston (or more) that allows "spring effect" to occur even with a light piston...then reaching more than 1000 pulse/mn.
I agree the displacer rod surface has to be large enough to let it rise with small increase in pressure!
Yeah, that would probably work. A planar spring on either side of the displacer is probably even a better solution than O-rings. The problem I guess is that it would limit the hot end temperature as the O-ring would burn and planar spring lose elasticity if too hot. Personally my aim is not to extract maximum RPMs or Pulses per minute (PPMs ?), but to extract maximum possible power out of an engine of given size. I suspect it can be more reliably achieved with a heavy power piston than springs.
But your idea is interesting, I'll certainly give it a thought. My reservation about high RPMs or PPMs is that when achieved they would reduce the power produced (very low torque) because it would not allow enough time for the gas to travel between the hot and cold ends in sufficient volumes due to viscosity. The faster PPMs the less amount of gas is involved in the movement which obviously reduces power.
@dmanofdland That is correct with the exception of my last Ringbom where the tube was already coming from the top like in this one. The old tube was only 3 mm inner diameter which was too narrow a passage for the air and air viscosity reduced the engine power a lot. This last tube is 5 mm and that made the engine a lot more powerful. Ideally the passage between the two cylinders should be as wide and as short as possible.
And thanks for the kind words.
blg53 8 months ago
@dmanofdland The cylinder at the bottom is connected to the glass cylinder on top. But it is not the displacer. The displacer is a piston that is attached to the end of the brass rod. It moves inside the metal cylinder. It is not tight, it has clearance of about 2 mm from the walls of the cylinder, its job is not to provide compression, but to move air inside the metal cylinder from hot to cool end and back (hence name "displacer").
blg53 8 months ago
@blg53 The force that moves the displacer is created by the air pressure exerted by the moving (heavy) glass power piston to the relatively large (8 mm) diameter of the displace's push rod. And yes it still moves it despite imperfect seal between the rod and its bearing. Because the displacer and its rod are made to be very light and the presence of the repelling magnets counteracts whatever weight id does have making it gravity-neutral. When not in motion the displacer rod sits (levitates)
blg53 8 months ago
@blg53 approximately mid-way through its stroke. It is actually take very little force to move it.
blg53 8 months ago
@dmanofdland No, no cyringe there. The displacer rod is a thin-walled brass tube with 8 mm outer diameter. The sleeve (bearing ) it slides through is a relatively thick-walled aluminim tube with 8 mm internal diameter. The choice of meterials is not perfect, both are too soft and as a result don't keep the polish well. But it was all I had. The seal is far from perfect, but I figured it was better to keep is slightly loose than too tight. I used graphite powder as a lubricant .
blg53 8 months ago
@dmanofdland Did not have to. The power piston and the cylinder are the two parts of a 20 cc glass cyringe, they are made to have a tight and accurate seal. All I had to do is to put a bit of weight on top of the pistin to give it inertia that acts the same way a flywheel does.
blg53 8 months ago
Good work!!!
alexblustar 10 months ago
I like this. Good job.
Paradoximoron2 1 year ago
@Paradoximoron2 Thanks mate, it was fun making it.
blg53 1 year ago
This has been flagged as spam show
Online Asian women **busizz4me.info**
alexandriaconcepcion 1 year ago
Have you seen the new diode flash lights that ar charged by movment of a magnet thru a tube just as what you have here, but with an inductive coil wound about the sleave in wich the magnetic piston moves.
TheBattleWagon 2 years ago
@TheBattleWagon
Yes, implemented in my later video
blg53 2 years ago
a work of art!
WorldStove 2 years ago 3
Flattery will get you everywhere .... :o)
blg53 2 years ago
fantastic u skipt a huge part of the inneficiancies of component drag great work friend
NOBOX7 2 years ago
Brilliant!
I had this theorical scheme in mind for a while... I guess the weight of the displacer is the main issue!
nicely done!
lecorfec 2 years ago
Thanks for kind words, I was pretty thrilled when it started chugging along. The displacer weight could be an issue if the displacer push rod diameter is too small, mine is 8 mm which seems enough for the levitating (gravity-neutral) displacer. I will experiment with the weight of the power piston though, because it's functional purpose is to provide the overdrive push for the displacer, what the flywheel normally does, so it should be reasonabley weighty.
blg53 2 years ago
I am afraid I do not have the same feeling! the power piston can be efficcient without to much weight the "spring gas" will play the role of the flywheel but displacer and piston mass should be balanced... check my videos (without displacer!!!).
lecorfec 2 years ago
Checked your videos. If I understand you correctly your pet Stirling system is laminal flow or thermodynamic ones which works on the resonant standing wave along the regenerator stack with temperature gradient. This is I guess what you call "spring gas".There the power piston has to be very light. Mine are more conventional Stirling engines, there are no "spring" in the gas there, ie no acoustic resonance.
blg53 2 years ago
The pressure to move the displacer rod and the displacer with it is provided by inertial overdrive of either flywheel (Ringbom) or a heavy (inertial) power piston (Free Piston system). The displacer push rod has to be of reasonably large diameter so that it provides sufficient application area for this pressure to exert enough force to move it (and the displacer with it). Al least this is my understanding of how it works.
blg53 2 years ago
Oh, and in this system the displacer should be as light as possible as the enegy to move it is subtracted from the output. The heavier the displace is, the less efficient the engine is, the less power output.
blg53 2 years ago
My guess is that you can probably fit two O-rings both side of the light displacer to store energy at each dead point and then increase the length of your cylinder to reach a 2.5 inch displacement of the piston (or more) that allows "spring effect" to occur even with a light piston...then reaching more than 1000 pulse/mn.
I agree the displacer rod surface has to be large enough to let it rise with small increase in pressure!
lecorfec 2 years ago
Yeah, that would probably work. A planar spring on either side of the displacer is probably even a better solution than O-rings. The problem I guess is that it would limit the hot end temperature as the O-ring would burn and planar spring lose elasticity if too hot. Personally my aim is not to extract maximum RPMs or Pulses per minute (PPMs ?), but to extract maximum possible power out of an engine of given size. I suspect it can be more reliably achieved with a heavy power piston than springs.
blg53 2 years ago
But your idea is interesting, I'll certainly give it a thought. My reservation about high RPMs or PPMs is that when achieved they would reduce the power produced (very low torque) because it would not allow enough time for the gas to travel between the hot and cold ends in sufficient volumes due to viscosity. The faster PPMs the less amount of gas is involved in the movement which obviously reduces power.
blg53 2 years ago
wonderful
roidroid 2 years ago
Cheers mate, this one is fun to play with.
blg53 2 years ago