Search results
Results from the WOW.Com Content Network
The pressure in the cylinder declines after cutoff as the steam pushes the piston down its bore. Cutoff is one of the four valve events. Early cutoff is used to increase the efficiency of the engine by allowing the steam to expand for the rest of the power stroke, yielding more of its energy and conserving steam. This is known as expansive working.
The reversing lever has a catch mechanism which engages with a series of notches to hold the lever at the desired cut-off position. This means that the operator does not have a full choice of cut-off positions between maximum and mid-gear, but only those which correspond with the notches.
In the simple case, this can be a relatively simple task as in the internal combustion engine in which the valves always open and close at the same points. This is not the ideal arrangement for a steam engine, though, because greatest power is achieved by keeping the inlet valve open throughout the power stroke (thus having full boiler pressure, minus transmission losses, against the piston ...
The first kind is the steam lap, which is the amount by which the valve overlaps the steam port on the live steam side of the piston or slide valve (i.e. the distance the valve needs to move to just begin to uncover the port).
Frederick Ellsworth Sickels (September 20, 1819; [1] Gloucester County, New Jersey – March 8, 1895; Kansas City [2]) was an American inventor, best known for the invention of a cut-off valve for steam engines in 1841. Sickels grew up in New York City, [3] where his father was Chief Health Officer. [4]
Period cutaway diagram of a triple-expansion steam engine installation, circa 1918. This particular diagram illustrates possible engine cutoff locations, after the Lusitania disaster and others made it clear that this was an important safety feature. A marine steam engine is a steam engine that is used to power a ship or boat.
Get AOL Mail for FREE! Manage your email like never before with travel, photo & document views. Personalize your inbox with themes & tabs. You've Got Mail!
A steam engine is a heat engine that performs mechanical work using steam as its working fluid. The steam engine uses the force produced by steam pressure to push a piston back and forth inside a cylinder. This pushing force can be transformed by a connecting rod and crank into rotational force for work.