The following is a reprint from The Engineer magazine dated April 15, 1905. Sent to us by Richard Mock, 159 Dirkson Ave., West Seneca, New York 14224.
Fig 1. illustrates the simple construction and convenient arrangement of the Bessemer engine, which is manufactured by the Bessemer Gas Engine Company, Grove City, Pennsylvania. One of the more noticeable features of this engine is the absence of mechanically operated valves. The horizontal shaft seen at the side of the engine is for operating the igniter only. The engine operates on the two-cycle principle, thus giving an impulse every second stroke, or one working stroke during each revolution of the crank shaft. This frequency of the working strokes gives the engine a steady motion and adapts it to electric lighting and other service requiring close speed regulation.
The operation of the engine is as follows: During the backward stroke of the piston, Fig 2, the mixture of air and gas is drawn into the front end of the cylinder through the port, A, while at the same time the previous charge is being compressed in the back end or combustion chamber, B. As soon as the piston completes the stroke, the charge is ignited and the piston driven forward by the burning gases. When the piston reaches the end of the stroke in the direction of the shaft, the exhaust port, C, is opened, and at about the same time the gas port, D, at the top of the cylinder is opened, admitting the fresh charge, which was compressed by the piston during the working stroke.
The incoming charge enters the cylinder under moderate pressure and drives the burnt gases before it, thus filling the cylinder very quickly with the fresh mixture. The piston serves as the gas valve and exhaust valve, thus rendering it unnecessary to provide valves for accomplishing the admission and exhaust of the charge. This reduces the number of working parts to the minimum.
The air and gas are drawn into the front end of the cylinder through the gas valve, E, located beneath the cylinder, Fig. 3 being an enlarged view of this valve. The air enters through the large annular opening, F, Fig. 3, while the gas is admitted through a series of small holes or ports, G. The valve, H, when seated closes the opening, F, and the small ports, G, both being opened simultaneously by the valve, which is raised by the suction of the piston. Air enters the valve body through the air pipe, I, Fig. 2, which is connected with the interior of the bed to avoid drawing in dust and dirt.
The governor is located in the gas pipe at the side and on a level with the top of the cylinder, the speed being regulated by throttling the gas and thus modifying the force of the explosion to meet the requirements of the load. The cylinder and back cylinder head are water jacketed, the front head having no jacket, since it is subjected to the low temperatures due to the slight compression of the fresh charge or mixture. This engine is provided with a piston rod, crosshead and guides the same as a steam engine; in fact, the construction throughout is in accord with the best practice in steam and gas engine construction.
The stuffing box in the front head is subjected to only moderate pressures and temperatures, consequently no trouble is experienced in maintaining a tight and durable joint. The working parts are enclosed by a neat hood and crank case which not only prevents dust and dirt from reaching the vital parts, but renders the engine self-oiling and adapted to making long continuous runs with the minimum of attention.
The connecting rod is of the marine type and extra heavy. The pins also are large and provided with means for obtaining ample lubrication. The main shaft bearings are provided with chain oilers which insure copious lubrication at all speeds, and at the same time pre vent any waste of oil.
The piston is oiled by means of a special automatic sight feed oiler. The piston is very long, thus providing liberal wearing surfaces and is provided with four wide packing rings. The engine is not only very simple, but is un usually massive, being designed for all kinds of service for which gas engines can be employed.