Зображення сторінки
PDF
ePub

The fame of the De Glehn Balanced Compound engine having reached America, the Pennsylvania Railroad ordered one from the French builders, and this is the one that was exhibited at the St. Louis Exposition.

The American purchasers specified that it should be exactly similar in design to the other engines of the De Glehn type running on the French lines, except heavier, as American express passenger equipment is much heavier than the European, and a few minor changes in detail were necessary in order to “make it fit” American tracks, and go where our engines will go. In spite of the fact, however, that this engine was built more heavy and powerful than the ones built for the French railways, it is hardly large enough to handle the very heavy passenger trains of the Pennsylvania lines, but with its proper load, with the lighter, but fast, service on certain divisions, it has been, and is, giving most excellent results; and the principle upon which the De Glehn engine is “balanced” is now being used with success by the Baldwin Locomotive Works in their Vauclain FourCylinder, Balanced Compound, and the Cole Balanced Compound engine built by the American Locomotive Works.

Fig. 17 represents the Walschaert gear that delivers the motion to the valves of the high-pressure cylinders

[graphic][ocr errors]

Fig. 16.-DeGlehn Balanced Compound. Pennsylvania Railroad.

[ocr errors][ocr errors][ocr errors]

Fig. 17.—Walschaert Valve Gear for High-Pressure Cylinders of the DeGlehn Compound

[ocr errors][subsumed][ocr errors][ocr errors]

FIG. 18.—Walschaert Valve Gear for Low-Pressure Cylinders of the DeGlehn Compound..

[graphic]

of the De Glehn Compound, and Fig. 18 shows the same type of gear as applied to furnish the motion of the valves of the low-pressure cylinders. In the arrangement of the latter it is seen that the link is driven by an eccentric on the main shaft; this shaft is termed a “crank axle,” because part of it is shaped to form two cranks to which the main rods of the two low-pressure cylinders (one on either side) are connected, and as the entire gear of the low-pressure, or second expansion, engine, of the cylinders and valves, both-are inside of the frame, it was clearly necessary that the eccentric should be placed on the crank axle inside the frame, with sheave and strap exactly like the Stephenson eccentric, except, of course, that but one eccentric is used for each link.' Outside of the frame the return crank on the main-pin actuates the valve gear of the high-pressure engine, which is the only part that can be seen in the photoengraving Fig. 16.

At this date the most powerful passenger engine ever built is the one depicted in Fig. 19, a recent production of the American Locomotive Company for the Lake Shore & Michigan Southern Railroad, and of which some of the principal dimensions are appended; here, again, the Walschaert valve gear is in evidence; and the heaviest and most powerful switching engine in existence at this time, built for the same road by the

« НазадПродовжити »