- Anonymous2 decades agoFavorite Answer
詹姆斯?瓦特（James Watt），西元一七三六年元月十九日生於蘇格爾西南部之格陵諾克港，一八一九年八月二十五日逝於伯明罕，享年八十有三。瓦特天資聰穎，記憶特強，尤具語言、音樂與化學天賦。幼承母教，後入文法學校，習拉丁文、希臘文及數學；然奠定其發明根基者，當為乃父之工廠，瓦氏自該處習得製具本事。年十七，瓦氏立志製作數學用具，首至格拉斯哥，旋赴倫敦，受名師指教；一七五七年再返格拉斯哥，製作四分儀、圓規、天秤等數理用具。一七六五年，因鑑於紐柯門式（Nen Comen）蒸汽機甚耗蒸汽，遂發明分離式冷凝器安置蒸汽機上，以救其弊。
Steam Engine Operation
The following diagram shows the major components of a piston steam engine. This sort of engine would be typical in a steam locomotive.
The engine shown is a double-acting steam engine because the valve allows high-pressure steam to act alternately on both faces of the piston. The following animation shows the engine in action:
You can see that the slide valve is in charge of letting the high-pressure steam into either side of the cylinder. The control rod for the valve is usually hooked into a linkage attached to the cross-head, so that the motion of the cross-head slides the valve as well. (On a steam locomotive, this linkage also allows the engineer to put the train into reverse.)
You can see in this diagram that the exhaust steam simply vents out into the air. This fact explains two things about steam locomotives:
It explains why they have to take on water at the station -- the water is constantly being lost through the steam exhaust.
It explains where the "choo-choo" sound comes from. When the valve opens the cylinder to release its steam exhaust, the steam escapes under a great deal of pressure and makes a "choo!" sound as it exits. When the train is first starting, the piston is moving very slowly, but then as the train starts rolling the piston gains speed. The effect of this is the "Choo..... choo.... choo... choo choo-choo-choo" that we hear when it starts moving.
On a steam locomotive, the cross-head normally links to a drive rod, and from there to coupling rods that drive the locomotive's wheels. The arrangement often looks something like this:
In this diagram, the cross-head is connected to a drive rod that connects to one of three drive wheels for the train. The three wheels are connected via coupling rods so they turn in unison.
- Anonymous2 decades ago
- 2 decades ago