For larger cars built for carrying large gangs of men, a three cylinder motor is used which drives through a clutch and gears, similar to that used on automobiles. It is located near the center of the axle and is supported on a frame that is independent of the car proper. This motor unit is easily removed from the car for inspection with all of the parts intact. A universal coupling is provided on the motor shaft to prevent strains due to changes in the alignment from being thrown into the motor. The motor of this car is started with a crank, and may be left standing with the motor running. As with the two cylinder car, the engine is reversible, and is lubricated by mixing the lubricating oil with the gasoline.
(58) Rotating Cylinder Two Stroke Cycle Motor.
An unusual type of two stroke cycle engine is that designed by M. Farcot for aeronautic work. It is of the rotating cylinder type in which the cylinders rotate about a stationary crankshaft, and unlike all previous two stroke motors, whether of the revolving or stationary cylinder type, no initial compression is performed either in the crank-case or otherwise.
Fig. 63. Farcot Rotary Two Stroke Motor.
Undoubtedly the two-cycle rotating multi-cylinder engine has a future when some of the particularly difficult designing problems involved in its production have been successfully tackled. Crank case compression has had its devotees, but so far it has entailed the use of a low compression, owing largely to the difficulties involved in lubricating the bearings and maintaining gas-tight joints, besides other defects. Some of these barriers appear to have been surmounted in this design.
Fig. 63 of the accompanying drawings is a sectional side elevation of the engine, which, it will be seen, is similar in general disposition to the usual arrangement of the rotating cylinder type. In this particular case, however, the short end A of the stationary crankshaft is reduced in diameter at B, and on this part are mounted ball bearings C carrying the circular casing of a rotating centrifugal blower D. To the inner end of the hub of this blower is attached a gear wheel E, the teeth of which mesh with small intermediate pinions carried on a spider F attached to the crankshaft. These pinions are in turn driven by an internally toothed ring G attached to the hub of the crank case H. Thus the blower D is driven in the opposite direction to the crank-case and at a higher speed. In the interior of the blower casing radial blades K are provided.
Fig. 64. Farcot Fan Plates.
A hollow annular casing L is bolted to the cylinders, and communicates with their interiors by means of inlet ports M covered and uncovered by the pistons.