No hay artículos en el carro
No hay artículos en el carroOmar V
Comentado en México el 17 de marzo de 2025
No se pudo cargar el contenido.
Spiros Giagozoglou
Comentado en Australia el 10 de abril de 2024
Easy to assemble. Works very well. Fun toy for the desk and can be educational for kids. They can try to search internet to find out how it works.
Rafael Rojo
Comentado en México el 27 de agosto de 2023
La máquina funciona muy bien y es sorprendente. Tiene buenos acabados.
Omar Tobias
Comentado en México el 24 de noviembre de 2022
No se pudo cargar el contenido.
Edward H. Carlson
Comentado en los Estados Unidos el 12 de julio de 2020
This an elegant engine, both in appearance and in its functioning. You can see all the parts moving. Of my five Stirling engines, it is the best performer at low temperatures. The Stirling engine is a heat engine, just as are steam engines, gasoline engines, hurricanes and the "drinking bird" toy busily bobbing.The large cylinder at the bottom contains the displacement piston. I will call it the displacer. It is driven by a crank on the flywheel. In the small cylinder, the power piston cranks the flywheel twice each revolution, making everything move. The displacer moves the air in the displacement cylinder, alternately to the bottom plate to be heated and then to the top plate to be cooled. This air is confined to the interior of the engine, so that when heated (or cooled), it cannot expand (or contract) but instead must increase (or decrease) its pressure compared to the air outside in the room. The pressure differences cause two power strokes per revolution, one in which the pressure in the engine is below room pressure so the power piston is pushed down, and the other in which the greater pressure inside the engine pushes upward on the power piston. Crucial to a Stirling engine is that the cranks control the pistons so that the power piston is always a quarter of a turn behind in its motion compared to the displacement piston.Here is how this offset between piston motions causes the needed pressure changes. The downward power stroke begins when the power piston is at the top of its cylinder and the displacer is at the middle of its downward stroke. At this point in time, the air is divided evenly between the cool upper region and the warmer lower one. The turning flywheel pushes the power piston to start the power stroke. As the power stroke continues, the displacer pushes more air into the cool upper region, and the overall pressure in the interior drops below room pressure.When the power piston reaches half way down in its power stroke, the displacer is all the way down, so all the air is in the cooler part of the interior space. The pressure in the interior of the engine is at its lowest point so the room air is pushing hardest downward on the power piston. This is the most powerful part of the power stroke, the more so because here the power crank is oriented to furnish its highest torque. The power piston continues downward, reaching the end of this power stroke. The upward power stroke now begins, and the explanation as to how it functions mirrors that of the downward stroke.You can see the two power strokes, one down and the other up! Start the engine on a hot cup. After it is moving at about 1 rps (60 rpm) take it off and set it on the table. Watch as it slows to a stop. In the last 2 or 3 revolutions the flywheel moves with an easily seen jerk at every power stroke. I find it easiest to see this by watching the power crank. The up stroke is harder to see because the engine is not rotationally balanced. The flywheel probably is balanced, but the combined weight of the pistons pulling down unbalances the system.This explanation raises some questions. The main one is that we know that the heat flow between the air and its nearby plate is not instantaneous. But there is a hint that it does happen very quickly. As the engine runs, the rim of the top plate becomes much hotter than the center of the plate. (I measured the plate temperature with one of those thermometer "guns" whose laser pointer shows a red dot showing just which spot is being tested.)The rim is the place that the hot air from below the displacer enters the top space. So for that place to be much hotter than the rest of the plate indicates that much of the heat from below gets dumped here quickly, before the air moves further into the cold region.Another point: the engine leaks air from the space between the power piston and its cylinder wall. This leak is slow enough that it does not affect the efficiency of the engine. But the leak is crucial! If the engine did not leak, it would soon not run at all! The air inside the engine becomes much hotter than outside, and its pressure therefore would be enough to push the power piston all the way up and lock it there! But this is avoided because some interior air leaks out, restoring the interior pressure (averaged over a cycle) to match the outside pressure.You can observe this leak yourself. Hold your cold engine with its power cylinder horizontal. Turn the flywheel so that the power piston is at one end of its motion, and hold it there for about 20 seconds. Then turn the flywheel so the piston is at the other end of its allowed motion, and release it. You should see the piston move back close to where you had held it! Repeat, starting this time with the piston at the other end.
wetwestie
Comentado en Singapur el 4 de diciembre de 2020
I got this for my very gadget driven husband and he loved it. He loves seeing how things work and this is a fun toy that he uses almost daily. You should definitely wipe the bottom of the device dry when you are done using it.
Placeholder
Comentado en India el 14 de octubre de 2016
Nice product, the side transparent portion makes me to understand the mechanism easily. I've tested it with a cigarette lighter, and excellent
KMキャンプ大好き
Comentado en Japón el 25 de enero de 2015
バルク品ですが、商品は素晴らしい物でした。、低温度で動くものですが、手のひら上でちゃんと動きました、感動です。
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