Gas-Engines and Producer-Gas Plants

the utmost importance. The piston does its work under very peculiar conditions. It is driven at great linear velocities; and

the explosion-chamber, it uncovers more and more of the frictional surface constituting the interior wall of the cylinder. This surface, as a result, is regularly brought into contact with the ignited, expanding gases after each explosion. For this rea

nce that cost should not be considered. Besides, the surplus oil which is usually caught in the drip-pan is by no means

al oils, therefore, are suitable for the purpose. Those oils should be selected which, with a maximum of viscosity, are capable of withst

dish. In order that the temperature may be uniform the vessel is shielded from the direct flame by interposing a piece of sheet metal or a layer of dry sand. As soon as gases begin to arise a lighted ma

s to evaporate at about 365 degrees F. Ignition occurs at 535 degrees F. The point of complete combustibility lies between 625 and 645 degrees F. Oil of this quality solidifies at 39

e preferably lubricated with fresh oil, because their constant movement renders inspection difficult and the control of lubrication irksome. A good, industrial mineral oil of usual market quality will be found satisfactory. In order to bring home

a small iron arm f is suspended, which arm dips in the oil contained in the cup G of the oiler. When the shaft a is turned this arm, as it sweeps through the oil-bath, collects a certain quantity of oil which it deposits on the collector b. From this spindle the oil passes through an outlet-pipe opening into the bottom of the oiler, and thence to the cylinder. The entire apparatus is closed by

automatic En

ricators are nowadays widely used on large engines. It is advisable to add a little salt

t the inlets of cylinders. In order that pressure-lubricators may operate perfectl

and of the two connecting-rod hea

ht-feed lubr

ing the piston and end

ected either by a splasher mounted in front of the cylinder or by a lubricator secured to the connecting-rod by which the pivot is lubricated through the medium of a small tube supplying special oil (Fig. 21). The head of the connecting-rod where it meets the crank, must also be carefully lubricated because of the important nature of the work which it must perform, and because of the shocks to which it is subjected at each explosion. For motors of high power the system which seems to give most satisfactory results is that illustrated in Fig. 70. The a

d of oiling th

the bearing by capillary attraction with a constant quantity of oil, the supply being regulated by varying the thickness of the cotton. When the motor is stopped, the cotton should be removed in order that oil-feeding may not uselessly continue. Glass, sight-feed lubricators with stop-cocks, are very often used on crank-shafts. They are cleaner and much more easily regulated. Of all shaft-bearing lubricators, those which are most to be recommended are of the revolving-ring type (Fig. 72). They presuppose, however, bearings of large size and a special arrangement of

tton-waste

ith a drain-cock and a glass tube in order to

he system adopted consists of a small tube curved in any convenient direction and discharging in the stem

g type of be

over the crank. A more serious difficulty is presented when the oil from a crank-bearing finds its way to the hub of the fly-wheel, whence it is driven by the centrifugal force to the rim. The oil is not only splashed against the walls of the engine-room, but it also de

haft with

t a time without a stop. This happens in the case of mill and shop engines. Lubricators of large