[Figure 79] shows a similar pump with a strainer over the intake, the outlet being through the holes L in the pipe H. In the pump illustrated in [Figure 80] the plunger is hollow, and fills with oil during an inward stroke; the oil is forced out to a passage around the plunger, and passes to the bearings by the holes H.
Fig. 80.—Oil Pump with Hollow Plunger
[Figure 81] shows two methods of preventing oil from leaking out around the plunger. In the first of these, a channel is formed in the upper part of the pump cylinder, leading to the crank case; any oil that leaks past the plunger flows to the crank case by this drain pipe and is not wasted. In the second method a packing of soft material, such as cotton or asbestos, is placed around the plunger, and is pressed against it by a gland, which is like a thick washer. A packing nut screws against the gland, and thus squeezes the packing against the plunger.
Fig. 81.—Methods of Preventing Oil Leaks
Fig. 82.—“Titan” Lubricator
A mechanical lubricator, or oiler, consists of several small oil pumps placed in an oil tank, each pump feeding one special bearing, and all driven by the engine. [Figure 82] is a top view of a 2-cylinder horizontal engine oiled by a six-feed oiler. The bearings that it oils are the two ends of the crank shaft, the two ends of the cam shaft, and the two cylinders; the gears and other bearings are oiled by splash. An oiler is adjustable, so that it will feed any desired quantity of oil.
