The result is that the gas valve lever remains closed and hence the gas valve misses, that is, it does not take in any gas on the suction stroke.
But as long as the speed is right the balls do not fly apart wide enough to throw over the lever and the roller, the cam strikes it and the gas valve lever opens the gas valve.
The Throttling Governor.—This governor also has a pair of flyballs which are rotated in the same way as in the governor described above. The ver tical shaft with the grooved sleeve works a lever that opens and closes a gas valve, or throttle, as it is called, in the gas supply pipe more or less in order to keep the speed uniform. It is shown in Fig. 13.
How the Engine is chief parts of the engine to be oiled are (1) the piston, (2) the crankshaft bearings, and (3) the connecting rod bear ings. Besides, there are numerous other smaller moving parts which must be lubricated.
piston has a groove cut in its periphery and as this passes the oil duct it fills with oil, and so lubricates the piston and the cylinder.
The bearing of the connecting rod on the wrist pin is lubricated by an oil tube from the same oil cup, which sets in the piston over and directly in a line with an oil pipe in the bearing, and this is also shown at B.
The bearings of the crankshaft are lubricated either by (1) sight feed oil cups or (2) by ring oilers. A ring oiler has an oil well, or reservoir, which is filled with oil and a metal ring which is large enough so that when it is hung on the shaft the lower edge dips into the oil, as shown at C.
As the shaft revolves the ring turns a little at a time with it and carries oil to the bearing as it moves round. With this system of oiling there is never any danger of hot boxes.
The bearings of the connecting rod on the crank shaft are oiled by a wiper oiler. A sight feed of cup is mounted on an upright rod, or on the crank guard, that is, a heavy metal sheet arched over the crank. The wiper consists of an oil tube set in the crank-pin bearing and having in it a piece of lamp wick.
As the crank revolves, the lampwick strikes the open end of the oil cup pipe and wipes off the oil. When the wick is soaked with oil it reaches the bearing and the crankpin and keeps them lubricated.
The numerous other small parts to be lubricated are oiled by small oil cups or by hand through oil • Kinds of Water Circulating Systems.—There are two simple ways to keep water circulating around the cylinder to keep it cool, and these are (1) by using a stream of city water, or water that is under pressure from any other source, and (2) by employ ing a water tank.
Using a Steady Flow of Water.—Where a steady flow of water can be had it is simply piped into the cylinder jacket through a .cock at its lower end; the heated water is then carried off by a spout near the top of the jacket, as shown at A, B and C in Fig. 38, when it empties into a funnel and is carried away by the waste pipe to a sewer.
The Cooling Tank, or Thermo-Siphon System.— Where flowing water is not available engines of from 1 to 15 horsepower can be cooled by means of a tank, as shown in Fig. 84.
When the water in the cylinder jacket heats up it gets lighter and rises through the pipe into the tank, while the cold water, since it is the heaviest, falls to the bottom of the tank and then flows on back into the cylinder jacket. In this way the water is circulated, or siphoned, by its thermal action., that is the action of the heat itself.
The Exhaust Pot and Exhaust the burnt gases in the cylinder are exhausted directly into the air they sound like the staccato reports of a Lewis machine gun mowing down a detachment of boches.
To silence these noises an exhaust pot is used, and this is simply a large iron, or other vessel, as shown in Fig. $5, into which the burnt gases are driven by the exhaust stroke; they then expand in it until the pressure they exert is just about that of the atmos phere, when they exhaust into the open air without noise.