How does a valve gear work?
How does a valve gear work?
The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing gear. It is sometimes referred to as the “motion”.
How does a steam valve work?
An expansion valve is a device in steam engine valve gear that improves engine efficiency. It operates by closing off the supply of steam early, before the piston has travelled through its full stroke. This expanding steam is still sufficient to drive the piston, even though its pressure decreases as it expands.
How does Walschaerts valve gear work?
The Walschaerts valve gear is an improvement on the earlier Stephenson valve gear in that it enables the driver to operate the steam engine in a continuous range of settings from maximum economy to maximum power. The valve opens to admit steam to the cylinder just before the start of a piston stroke.
Do steam engines have gears?
The steam locomotive, as commonly employed, has its pistons directly attached to cranks on the driving wheels; thus, there is no gearing, one revolution of the driving wheels is equivalent to one revolution of the crank and thus two power strokes per piston (steam locomotives are almost universally double-acting.
What is valve Gearbox?
A gearbox is an actuator that produces a mechanical advantage through a series of gears resulting in reduced input torque to operate a valve. Gearboxes can be driven via a manual handwheel or electric multiturn actuator. Reversing gearboxes are also available.
How do steam engines go backwards?
The left pedal, when fully released, allows the engine to move the car forward as the throttle is opened to apply steam to the engine. When the left pedal is fully pressed and held to the floor while the throttle is opened to send steam to the engine, the engine moves the car backwards.
Can Ball Valves be used for steam?
Ball valves, like all valves, are generally rated at a lower pressure for steam service than for liquid or dry gaseous service. Wet steam is damaging to all valve parts at the moment of opening and closing, or when throttling. Free ammonia in the low pressure or condensate will attack bronze.
What is main steam stop valve?
A main steam stop valve is a valve usually connected directly to the boiler for the purpose of shutting off the steam from the main steam line.
Can a locomotive go in reverse?
They Can… Modern diesel-electric or electric locomotives can run equally well in either direction. There is a lever called a “reverser” in the locomotive cab that determines the direction of travel. It has three positions: forward, neutral, and reverse.
What is Valve Gearbox?
How is valve gear used in a locomotive?
“Valve gear” is the mechanism used to move the valve system that opens and closes the inlet and exhaust ports that let steam into and out of a locomotive’s cylinders. There are many different designs of valve gear, including the following more commonly used types:
Where can I find steam engine valve gear?
Windows Version by Charles Dockstader HCR 69 Box 3111 California Valley CA 93453 805 475 2519 UpDated Mar 20, 2009 Windows Ver 2.7.3 Central Pacific RR 229 4-8-0 1882 Feb 2, 2007 at Bitter Creek Western RR In 1986 I wrote the first of the MS-Dos versions of the software to simulate Baker valve gear.
How are the valves used in a steam engine?
The valves on a steam engine control the flow of steam in and out of the cylinders. Several types of valves were developed over the years, but most fall within three main catagories: Poppet valves similar in principle to those used in internal combustion engines.
Who was the inventor of the valve gear?
Walschaerts (no apostophe) valve gear invented by Belgian railway engineer Egide Walschaerts in 1844, gained near-universal acceptance in the early 20th century. It is commonly externally mounted and driven by an eccentric crank mounted on the end of the locomotive crank-pin.
How does a valve gear work? The valve gear of a steam engine is the mechanism that operates the inlet and exhaust valves to admit steam into the cylinder and allow exhaust steam to escape, respectively, at the correct points in the cycle. It can also serve as a reversing gear. It is sometimes referred…