Search results
Results from the WOW.Com Content Network
Reversing lever. This is the most common form of reverser. It is also known as a Johnson bar in the United States. It consists of a long lever mounted parallel to the direction of travel, on the driver’s side of the cab. It has a handle and sprung trigger at the top and is pivoted at the bottom to pass between two notched sector plates.
Stephenson valve gear is a convenient arrangement for any engine that needs to reverse and was widely applied to railway locomotives, traction engines, steam car engines and to stationary engines that needed to reverse, such as rolling-mill engines. It was used on the overwhelming majority of marine engines.
In a steam engine, cutoff is the point in the piston stroke at which the inlet valve is closed. On a steam locomotive, the cutoff is controlled by the reversing gear . The point at which the inlet valve closes and stops the entry of steam into the cylinder from the boiler plays a crucial role in the control of a steam engine.
An oscillating cylinder engine cannot be reversed by means of the valve linkage (as in a normal fixed cylinder) because there is none. Reversing of the engine can be achieved by reversing the steam connections between inlet and exhaust or, in the case of small engines, by shifting the trunnion pivot point so that the port in the cylinder lines up with a different pair of ports in the port face.
The valve gear, actuated by connection to the driving wheels, ensures that steam is delivered to the piston with precision. Types are slide valves, piston valves or poppet valves. [2] [3]: 62 Valve chest / Steam chest Valve chamber next to the cylinder (24) containing passageways to distribute steam to the cylinders. [6]: 41 [3]: 75 Firebox
A reversing valve is a type of valve and is a component in a heat pump, that changes the direction of refrigerant flow. By reversing the flow of refrigerant, the heat pump refrigeration cycle is changed from cooling to heating or vice versa. This allows a residence or facility to be heated and cooled by a single piece of equipment, by the same ...
The Baker valve gear replaces the expansion link of the Walschaerts gear with an assembly of levers and links which produces the same effect of allowing continuous variation valve travel. The remainder of the gear is the same, so that the return crank and combination lever take the same form, although the proportions are usually modified.
The Hackworth valve gear is a design of valve gear used to regulate the flow of steam to the pistons in steam engines. It is a radial gear, with an actuating lever driven from the crank. The drive may be taken directly from the crank or indirectly via a return crank (as in all pictures). The other end of the actuating lever is attached to a die ...