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Title: |
1890 Article-Stearns Manufacturing Co., 10 X 16 Steam Engine |
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Source: |
The Steam User 1890 pg 106 |
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Insert Date: |
4/20/2011 4:30:08 PM |
By observation of the cut on the opposite page it will be seen that the design of this engine is singularly symmetrical and elegant. The metal is judiciously distributed where it will do the most good, and, at the same time, the lines are graceful and appropriate.
It will also be noticed that two bearings are used upon the engine frame for the main shaft. The advantage of this will be obvious. It increases the surface of the main bearings immensely, permits the use of a double crank with two discs, and brings the strain of the work totally within the engine, so that, instead of the crank-pin tending at each stroke to throw the engine back and forth upon its foundation, with the outboard bearing as a fulcrum, the engine is self-contained and manifests no disposition to drag itself out of line at every revolution.
Owing to the mischievous effect of the expansion of engine cylinders when bolted down to foundation or to the bed frame, the cylinders are made overhanging. The manufacturers say they are aware that this has been objected to, at times, by those who have not given thought to the details of construction, but by a moment's comparison of the relative stress upon the stud bolts of the front head of the cylinder, due to its weight, and that due to the pressure of steam upon the back head, the latter would be found so much greater that the former becomes inconsiderable. For instance, take a 16-inch engine; the weight of cylinder and attachments may be 2,000 pounds. The area of a 16-inch cylinder is 201 inches, and the pressure at 100 pounds brings the strain up to 20,000 pounds; therefore the bolts, which are calculated to safely resist the latter pull, will hardly feel the small weight thrust upon them.
The ports for admission and exhaust are large, so as to give the engine the instant benefit of all the pressure in the steam-chest.
The slide valve on engines of 16 inch diameter and over is balanced by a pressure plate scraped to a fit upon the back of the valve. This plate bridges over the valve and relieves it of steam pressure, so that it is possible to run them by hand with throttle open. (These engines are manufactured by the Stearns Manufacturing Co., Erie, Pa.) |
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1890 Stearns Manufacturing Co., 10 X 16 Steam Engine
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